JP6745459B2 - Water content observation device, water content observation method, and cultivation device - Google Patents

Description

The present invention relates to a water content observation device, a water content observation method, and a cultivation device for observing the water content contained in a plant.

Conventionally, it has been known that a normal plant has an electric potential difference between inside and outside of a cell to generate an electromotive force. The mechanism of such electromotive force generation can be explained based on, for example, an electrophysiological model of axial organs of higher plants. In particular, various methods for nondestructively investigating the state of roots of plants (for example, water stress) by utilizing electromotive force between roots and soil have been proposed.

As a prior art for measuring water stress in a plant using the above method, for example, Patent Document 1 is known. In Patent Document 1, a first non-polarizing electrode is connected to a plant, a second non-polarizing electrode is connected to soil in which a plant is vegetated, and a potentiometer is provided between these two non-polarizing electrodes. By measuring the electromotive force between the two non-polarizable electrodes with this potentiometer, the water stress on the plant can be measured.

JP 2001-272373 A

As an example of plants, in order to improve the sugar content of fruits such as tomatoes, the amount of water contained in leaves of tomatoes is usually considered. However, the water content of the tomato leaves and the like is not determined only by the water provided by the manual irrigation by the grower (farmer) or the automatic irrigation of the irrigation device (for example, the sprinkler), but the environmental conditions around it (for example, the temperature, It is known that the property of fluctuating under the influence of humidity). The above-mentioned Patent Document 1 does not pay attention to such a property, and it is not possible to specifically control the water content of the tomato leaves or the like in consideration of the influence of the surrounding environmental conditions.

Also, in order to improve the value (that is, unit price) of tomatoes, it is possible to improve the sugar content of tomatoes. To increase the sugar content, at what timing and how much irrigation should be performed. Was largely due to artificial arrangements such as the farmer's past experience and intuition.

Generally, increasing the sugar content of fruits such as tomatoes leads to an improvement in quality and unit price, but on the other hand, it is not easy to grow, so the yield decreases and the production volume decreases. The sides are strong. In other words, there is a trade-off relationship between higher fruit functionality and yield. Therefore, it is expected that the yield will be improved and the productivity will be increased in the future.

In addition, as described in Patent Document 1, when an electrode is connected to a plant or soil for measurement, there is a concern that the root of the plant may be damaged depending on the measurement time.

The present invention has been made in view of the above-mentioned conventional situation, and in consideration of the influence of surrounding environmental conditions, it is possible to flexibly control the amount of water contained in plants containing fruits such as tomatoes. It is an object to provide a water content observation device, a water content observation method, and a cultivation device.

The present invention is a water content observing device for observing the water content of a plant , wherein a near-infrared laser reference light of a first wavelength having a characteristic of being hard to be absorbed by the water by optical scanning is used for the water content of the plant . A first light source that irradiates a preset irradiation range including a calculation target site, and a second wavelength near-infrared laser measurement light having a characteristic of being easily absorbed by moisture by the optical scanning is directed to the irradiation range . a second light source for irradiating Te, in certain measurement period, the near infrared reflected at each irradiation position of the irradiation range and the reflected light of the reflected said near-infrared laser reference beam at each irradiation position of the irradiation range Based on the reflected light of the external laser measurement light, a water content calculation unit that repeatedly calculates the water content contained in the water content calculation target site of the plant, and an environmental control device that controls environmental conditions around the plant. A control that instructs the environmental control device to change or maintain the environmental condition based on a change in the amount of water contained in the water content calculation target part of the plant that is connected and calculated by the water content calculation unit. And a water content observing device.

Further, the present invention, a water content observing device, based on the time-series transition of the water content calculated by the water content calculation unit in a part of the measurement period, a predetermined amount of water to the plant. Provided is a cultivation control unit including a cultivation control unit for irrigation.

Further, the present invention is a method for observing a water content in a water content observing apparatus for observing the water content contained in a plant, wherein the first light source has a characteristic of being close to a first wavelength having a characteristic that it is hardly absorbed by water by optical scanning. the infrared laser reference beam is irradiated toward the predetermined irradiation range including moisture value computation portion of the plant, the second light source, by the optical scanning, the second wavelength with easy property to be absorbed in water Irradiate the near infrared laser measurement light toward the irradiation range , in a constant measurement period, the reflected light of the near infrared laser reference light reflected at each irradiation position of the irradiation range and each of the irradiation range Based on the reflected light of the near-infrared laser measurement light reflected at the irradiation position , repeatedly calculating the water content in the water content calculation target site of the plant, an environmental control device for controlling the environmental conditions around the plant The present invention provides a method for observing water content, which is connected to the environmental control device and instructs the environmental control device to change or maintain the environmental condition based on the change in increase/decrease of the water content in the calculated water content calculation target site of the plant.

According to the present invention, it is possible to flexibly control the amount of water contained in a plant containing fruits such as tomatoes in consideration of the influence of surrounding environmental conditions.

Conceptual explanatory view showing an example of the usage situation of the plant detection camera of each embodiment The block diagram which shows the structural example of the plant observation system in which the plant detection camera of each embodiment is arrange|positioned in the greenhouse along with the control apparatus for controlling the environmental conditions in a greenhouse. Block diagram showing an example of the internal configuration of the plant detection camera in detail The figure which shows in detail an example of an internal structure of the image determination part of a plant detection camera. Flowchart explaining an example of the initial setting operation in the control unit of the plant detection camera Explanatory drawing of the principle of moisture detection in the invisible light sensor A graph showing an example of spectral characteristics of near-infrared light with respect to water (H ₂ O) The flowchart explaining an example of a detailed operation procedure regarding the detection of the water contained in the leaf of the plant in the invisible light sensor The flowchart explaining an example of the calculation procedure of the moisture index in step S18-5. The figure explaining an example of the measuring method of a comparative example. (A) A graph showing an example of the intensity of reflected light with respect to the wavelength of near-infrared light when irradiating the leaves with near-infrared light outdoors, (B) a white background board bd was installed indoors and outdoors A graph showing an example of the intensity of reflected light with respect to the wavelength of near-infrared light when irradiating the leaves with near-infrared light Illustration of an example of how to attach leaves to a white background board A graph showing an example of the time change of the standardized pixel average moisture index in the first water potential control experiment A graph showing an example of a temporal change of the standardized pixel average moisture index in the second water potential control experiment Graph explaining an example of irrigation volume and irrigation timing The flowchart explaining an example of the optimal irrigation flow search procedure of 1st Embodiment. The figure which shows an example of the user interface (UI) screen regarding water potential control. The figure which shows an example of the search irrigation amount input screen popup-displayed on the UI screen. The flowchart explaining an example of the water stress control (cultivation control) procedure of 1st Embodiment. The figure which shows typically an example of (A)-(D) water stress profile. The flowchart explaining an example of the optimal irrigation amount search procedure in the modification 1 of 1st Embodiment. (A) a diagram showing an image showing the water content of the leaf to be measured, taken by the plant detection camera of the second embodiment, and showing an example of an image of the leaf before the displacement, (B) second The figure which shows the image showing the water content of the leaf of a measurement object imaged with the plant detection camera of embodiment, and which shows an example of the image of the leaf after position gap. A graph showing an example of the time variation of the standardized pixel average moisture index in the water potential control experiment when the position shift occurs. Table showing an example of the standardized pixel average moisture index before and after the misalignment correction in time series The flowchart explaining an example of the position shift correction procedure of 2nd Embodiment. (A) It is a figure which shows the white background board used for detecting the position gap in the modification 1 of 2nd Embodiment, and is a front view of a white background board, (B) The modification of 2nd Embodiment. 2 is a side view of the white background plate shown in FIG. 1A, showing a white background plate used to detect the positional deviation in FIG. The figure explaining an example of the mechanical arrangement|positioning of the white background board and the plant detection camera in the modification 2 of 2nd Embodiment. (A) A frame image obtained by picking up foliage of tomato, and (B) a diagram showing a leaf occupying space obtained when a threshold is set to 0.05 m for a visible light image of (A), (C) A view showing the occupied space of the leaves obtained when the photographing distance is set to 1 m and the threshold value is set to 0.3 with respect to the visible light image of (A) Flowchart explaining an example of a threshold setting procedure Graph showing frequency distribution of reflection intensity ratio in all pixels Explanatory drawing showing an example of the relationship between temperature, relative humidity, and satiation Explanatory diagram showing an example of transition of leaf transpiration due to changes in temperature and relative humidity (A)-(D) The figure which shows typically each example of the water stress profile based on the transpiration of the leaf by the change of temperature and relative humidity. The figure which shows another example of the user interface (UI) screen regarding water potential control. The figure which shows an example of the fixed value setting input screen of the environmental control mode designated in the UI screen shown in FIG. The figure which shows an example of the satiety difference setting program input screen of the environmental control mode designated in the UI screen shown in FIG. The flowchart explaining an example of the control operation procedure of the surrounding environment conditions of the plant of 3rd Embodiment.

Hereinafter, each embodiment specifically disclosing the water content observation device, the cultivation device, and the water content observation method according to the present invention will be described in detail with reference to the drawings as appropriate. However, more detailed description than necessary may be omitted. For example, detailed description of well-known matters and duplicate description of substantially the same configuration may be omitted. This is for avoiding unnecessary redundancy in the following description and for facilitating understanding by those skilled in the art. It should be noted that the accompanying drawings and the following description are provided for those skilled in the art to fully understand the present disclosure, and are not intended to limit the claimed subject matter by these.

(First embodiment)
The plant detection camera 1 shown in FIG. 1 will be described as an example of the water content observation device of the present embodiment. In addition, the cultivation apparatus of the present embodiment is an example of a plant detection camera 1 shown in FIG. 1 and an example of a cultivation control unit that supplies fertilizer (for example, liquid fertilizer, that is, liquid fertilizer) or irrigates a plant with a predetermined amount of water. The fertilizer water supply device WF and the monitor 50 that displays a user interface screen 60 (see FIG. 17) and the like. The present invention can also be expressed as a water content observation method that executes each process performed by the plant detection camera 1. The plant detection camera 1 of the present embodiment can detect the distribution state of the presence or absence of water in the plant.

Here, the observation target of the plant detection camera 1 of the present embodiment is a plant, and as a more specific example, fruit vegetables will be exemplified and described. For example, in the growth of fruit and vegetables such as tomatoes, in order to increase the sugar content of the fruits of tomatoes, the water and fertilizers of roots and leaves were digested in an appropriate amount in photosynthesis, and as a result, when water and fertilizers were sufficiently supplied, It is known that water and fertilizer need to be in short supply. For example, if sufficient moisture is supplied to the leaves, the leaves will be in a healthy state and have a flat shape. On the other hand, if the water content to the leaves is considerably insufficient, the shape of the leaves will be warped. On the other hand, if the fertilizer in the soil is insufficient, symptoms such as yellowing of the leaves occur.

In the present embodiment described below, the plant detection camera 1 irradiates a plant (for example, a leaf) with a plurality of types of laser light having different wavelengths, and based on the intensity ratio of each diffuse reflection light reflected at the irradiation position of the leaf, An example of detecting leaf moisture will be described. In the present embodiment, the leaves of the plant are measured, but the leaves are not limited to the leaves, and other parts such as fruits, stems and flowers may be used. This also applies to the second embodiment.

(Outline of plant detection camera)
FIG. 1 is a conceptual explanatory diagram showing an example of a usage situation of the plant detection camera 1 of each embodiment. The plant detection camera 1 is installed at a fixed point in a greenhouse where fruit vegetables such as tomatoes are vegetated. Specifically, the plant detection camera 1 is installed, for example, on a base BS fixed to a mounting jig ZG mounted so as to sandwich a columnar support MT1 extending vertically upward from the ground. There is. The plant detection camera 1 is operated by being supplied with power from a power switch PWS attached to the support MT1, and outputs reference light LS1 and measurement light LS2, which are a plurality of types of laser light having different wavelengths, toward the plant PT to be observed. Irradiation is performed over the irradiation range RNG.

The plant PT is, for example, a fruit vegetable plant such as tomato, which grows roots from the soil SL filled in the soil culture pot SLP installed on the base BB, and has stems PT1, stems PT2, leaves PT3, and fruits. It has PT4 and flower PT5 respectively. The fertilizer water supply device WF is installed on the base BB. The fertilizer water supply device WF supplies water to the soil cultivation pot SLP via the cable WL, for example, according to an instruction from the wireless communication system RFSY connected via a LAN (Local Area Network) cable LCB2. As a result, water is supplied to the soil SL, so that the roots of the plant PT absorb water, and each part in the plant PT (that is, stem PT1, stem PT2, leaf PT3, fruit PT4, flower PT5). Is supplied with water.

Further, the plant detection camera 1 receives the diffuse reflection lights RV1 and RV2 reflected at the irradiation position of the plant PT irradiated with the reference light LS1 and the measurement light LS2, and further receives the ambient light RV0. As will be described later, the plant detection camera 1 has a normal camera function, and an image within a predetermined angle of view by the incident light of the ambient light RV0 (that is, a visible light image of the plant PT in the greenhouse shown in FIG. 1). ) Can be imaged. The plant detection camera 1 outputs to the data logger DL output data including various detection results (see below) and image data based on the diffuse reflected lights RV1 and RV2.

The data logger DL outputs the output data from the plant detection camera 1 via a LAN cable LCB1 and a wireless communication system RFSY to a management PC (Personal Computer, PC) of an office control room located geographically distant from the greenhouse. (Not shown). The wireless communication system RFSY controls the communication between the data logger DL in the vinyl house and the management PC in the control room in the office, and further, the communication specifications are not particularly limited, and further, the water and fertilizer for the soil cultivation pot SLP are controlled. An instruction from the management PC regarding supply is transmitted to the fertilizer water supply device WF.

A monitor 50 is connected to the management PC in the office control room, and the management PC displays the output data of the plant detection camera 1 transmitted from the data logger DL on the monitor 50. In FIG. 1, the monitor 50 displays, for example, the entire plant PT to be observed and the distribution state regarding the presence or absence of water in the entire plant PT. Further, the monitor 50 displays the enlarged distribution state of a specific designated portion (that is, the designated portion ZM designated by the zoom operation of the observer who uses the management PC) of the entire plant PT and the image data corresponding to the designated distribution portion. And are generated and displayed for comparison. Further, the monitor 50 as an example of the display unit displays a UI screen 60 including a leaf moisture monitoring screen Gm1 (see FIG. 17) described later.

The plant detection camera 1 is configured to include a visible light camera VSC and a non-visible light sensor NVSS. The visible light camera VSC (acquisition unit) uses the environmental light RV0 for visible light having a predetermined wavelength (for example, 0.4 to 0.7 μm), similar to the existing surveillance camera, for example. Image. Hereinafter, the image data of the plant imaged by the visible light camera VSC will be referred to as “visible light camera image data”.

The non-visible light sensor NVSS projects the reference light LS1 and the measurement light LS2 that are non-visible light (for example, infrared light) having a plurality of types of wavelengths (see later) onto the same plant PT as the visible light camera VSC. .. The non-visible light sensor NVSS uses the intensity ratio of the diffuse reflection lights RV1 and RV2 reflected at the irradiation position of the plant PT irradiated with the reference light LS1 and the measurement light LS2 to determine the water content at the irradiation position of the plant PT to be observed. The presence or absence of is detected.

In addition, the plant detection camera 1 outputs output image data (hereinafter, referred to as “detection result image data”) corresponding to the detection result of moisture of the invisible light sensor NVSS to the visible light camera image data captured by the visible light camera VSC, or It generates and outputs display data in which information about the detection result image data is combined. The display data is not limited to the image data in which the detection result image data and the visible light camera image data are combined, and may be the image data generated so that the detection result image data and the visible light camera image data can be compared. The output destination of the display data from the plant detection camera 1 is, for example, an external connection device connected to the plant detection camera 1 via a network (not shown), and is the data logger DL or the communication terminal MT (see FIG. 3). .. This network may be a wired network (for example, intranet, Internet) or a wireless network (for example, wireless LAN).

(Plant observation system with a plant detection camera installed in a greenhouse)
Next, a configuration example of the plant observation system 1000 in which the plant detection camera 1 of each embodiment is installed in a vinyl house VGH will be described with reference to FIG. FIG. 2 is a block diagram showing a configuration example of a plant observing system 1000 in which the plant detection camera 1 of each embodiment is arranged in a vinyl house VGH together with a control device 200 for controlling environmental conditions of the vinyl house VGH. .. It should be noted that the details of the operation of each part except the plant detection camera 1 and the air conditioner 227 among the parts shown in FIG. 2 are disclosed in published documents filed by the same applicant as the present application (specifically, JP-A-2014-57570). May be incorporated in the present specification. Here, the plant detection camera 1 is installed in the vinyl house VGH in a situation in which the environmental conditions (eg, temperature and humidity) around the plants (for example, fruits such as tomatoes) grown in the vinyl house VGH can be changed. A configuration example of the installed plant observation system 1000 will be described.

The plant observation system 1000 shown in FIG. 2 includes a plant detection camera 1, a control device 200, an environment sensor 211, opening/closing valves 213 and 215, a water supply pump 217, a side window 219, a ventilation device 221, and a ceiling curtain. 223, a side curtain 225, and an air conditioner 227. The control device 200 has a role as an environment control device capable of maintaining and changing the environmental conditions (for example, temperature and humidity) around the plants grown in the greenhouse VGH. The control device 200 is configured to include an I/F unit 201, a built-in clock 203, an arithmetic processing unit 205, and a storage unit 207. The storage unit 207 includes a first storage unit 207a, a second storage unit 207b, and a third storage unit 207c.

The main body of the greenhouse VGH is formed, for example, in an inverted U-shaped cross section and has a semicircular cross section, a pair of side walls that support the roof, and a pair of side walls that are orthogonal to the side wall and that face each other. Equipped with a wife wall part. Hereinafter, the direction passing through the pair of end wall portions is referred to as the longitudinal direction, and the direction passing through the pair of side wall portions is referred to as the lateral direction. The shape of the main body of the vinyl house VGH described above is an example, and the shape is not limited thereto.

The environment sensor 211 measures, as the ambient temperature of the plant PT, the room temperature in the vinyl house VGH around the plant PT and the underground temperature of the soil SL on which the plant PT is sown. Further, the environment sensor 211 preferably includes a humidity sensor that measures the humidity around the plant PT and an illuminance sensor that measures the illuminance around the plant PT. The environment sensor 211 outputs the measurement result (for example, the temperature and humidity around the plant PT) to the control device 200.

In the vinyl house VGH, a water supply device (not shown) including a watering device and a mist device is provided in order to water the community of the plant PT grown in the vinyl house VGH. The water sprinkling device includes two water sprinkling tubes, and when water is passed through the water sprinkling tubes, the water spouts in a shower shape or a fountain shape through the water passage holes. The two watering tubes are laid along the pair of side wall portions of the vinyl house VGH over substantially the entire length of the vinyl house VGH in the longitudinal direction. Further, the mist device includes a mist tube, and this mist tube has a large number of nozzles attached to a pipe wall through which water is passed, and when water is passed, water is sprayed from the nozzles.

This water supply device is an on-off valve consisting of a solenoid valve on the flow paths for supplying water to the water spray device and the mist device, respectively, in order to individually control the timing of ejecting water or hot water from the water spray device and the mist device. 213 and 215 are provided. The on-off valves 213 and 215 are individually controlled via the I/F unit 201 of the control device 200, and individually selected whether to supply water or hot water to the water sprinkling device and the mist device. Water or hot water supplied to the water sprinkling device and the mist device is pressurized to a predetermined pressure by the water supply pump 217.

The main body of the greenhouse VGH is in a closed state in which external light (for example, sunlight) incident from the roof portion is dimmed, and the external light (for example, sunlight) incident from the roof portion is irradiated to the plant PT without being dimmed. A ceiling curtain 223 that can be opened and closed between the opened state and the opened state is attached.

A side window 219 that can be opened and closed is formed on the side wall of the main body of the vinyl house VGH, and the opening amount of the side window 219 is adjusted, so that the ventilation resistance of the air when the outside air is taken into the main body of the vinyl house VGH. Is adjusted. In addition to the side window 219, a side curtain 225 is arranged on the side wall of the main body of the greenhouse VGH.

The side curtain 225 is a plant without dimming the external light (for example, sunlight) incident from the side wall of the main body of the greenhouse VGH and the external light (for example, sunlight) incident from the side wall. It is configured so that it can be opened and closed between an open state in which the PT is irradiated. The ceiling curtain 223, the side curtain 225, and the side window 219 are driven by the control device 200. When the ceiling curtain 223 and the side curtain 225 are opened/closed, the amount of heat flowing into the main body of the vinyl house VGH is adjusted. By opening/closing the ceiling curtain 223 and the side curtain 225, the inside of the main body of the vinyl house VGH is adjusted. The rate of temperature rise in the space is adjusted. Further, by adjusting the opening amount of the side window 219, the speed at which outside air is taken into the main body of the greenhouse VGH is adjusted. The ceiling curtain 223 and the side curtain 225 mainly contribute to the adjustment of the amount of heat entering the internal space of the main body of the vinyl house VGH. Further, the side window 219 is used when the outside air is taken into the internal space of the main body of the vinyl house VGH to adjust the temperature by utilizing the temperature difference between the inside and the outside of the main body of the vinyl house VGH.

The ventilation device 221 is arranged above the pair of end wall parts in order to form an air flow around the plant PT. The ventilation device 221 is operated as necessary, and when the side window 219 is open, the ventilation device 221 is operated, so that the outside air can be forcibly taken into the main body of the greenhouse VGH. The ventilation device 221 may be either a ventilation fan for exhausting air from the main body of the vinyl house VGH or a blower for taking in outside air into the main body of the vinyl house VGH. The blower is arranged inside the main body of the greenhouse VGH, and it is also possible to forcibly form an air flow around the plant PT and adjust the humidity around the plant PT. Further, the air conditioner 227 may be arranged in the vinyl house VGH, if necessary. The air conditioner 227 has a role of adjusting the temperature and humidity inside the greenhouse VGH.

The environment in which the plant PT grows in the main body of the greenhouse VGH controls the side window 219, the ventilation device 221, the ceiling curtain 223, the side curtain 225, the air conditioner 227, etc. in addition to the water supply device (not shown) described above. It changes depending on the situation. The control device 200 is an environmental control device for controlling environmental conditions (for example, temperature and humidity) around the plant PT, in addition to the water supply device (not shown) described above, a side window 219, a ventilation device 221, and a ceiling curtain. 223, the side curtain 225, the air conditioner 227, etc. are controlled.

The control device 200 opens and closes the on-off valves 213 and 215, adjusts the water supply pressure and water temperature of the water pump 217, opens and closes the ceiling curtain 223 and the side curtain 225, adjusts the opening amount of the side window 219, operates and stops the ventilation device 221. Controls ventilation to a blower pipe (not shown). An electromagnetic contactor (electromagnetic relay) that turns on and off the power supply to each device is used to start and stop the power supply to each device. The control device 200 is housed in a housing attached to the main body of the vinyl house VGH and constitutes a control panel. The control device 200 also acquires environmental condition information (for example, temperature information, humidity information) from the environmental sensor 211 in a predetermined cycle, and acquires the acquired environmental condition information and instruction information from the plant detection camera 1 (see below). Is used to perform the control described above. The specific operation of the control device 30 will be described later. The control device 200 includes a device such as a microcomputer that operates according to a program as a main hardware element.

For example, the control device 200 is configured as a personal computer, receives the output of the environment sensor 211 through the I/F unit 201, and gives an instruction to each device. That is, the control device 200 can control each device by executing the program. The control device 200 may be configured as a dedicated device instead of a general-purpose personal computer.

As shown in FIG. 2, the control device 200 includes an I/F unit 201 to which the above-described devices and the environment sensor 211 are connected, a storage unit 207 that stores various data, a real-time clock that measures the date and time, and the like. And a built-in clock 203. In addition, the control device 200 is provided with an arithmetic processing unit 205 that controls each of the above-described devices using information on the environmental conditions acquired from the environmental sensor 211 through the I/F unit 201 and various data stored in the storage unit 207. .. The I/F unit 201 includes an electromagnetic contactor (not shown) that turns on/off power supply to each device. The time interval at which the I/F unit 201 acquires the environmental condition information from the environmental sensor 211 is set to, for example, about 1 to 15 minutes. A device (not shown) serving as a user interface is connected to the I/F unit 201 so that the user can set the contents to be stored in the storage unit 207 and adjust the time of the internal clock 203 through the device. is there.

The first storage unit 207a stores the ambient temperature and the water amount in association with each other according to the growth stage of the plant PT. The second storage unit 207b stores the ambient temperature and the timing of sprinkling in association with each other according to the growth stage of the plant PT. The third storage unit 207c stores the number of days after germination of the plant PT and the environment sensors 211 having different height positions in association with each other.

For example, in order to lower the temperature of the leaf PT3 of the plant PT, the control device 200 controls the ceiling curtain 223 and the side curtain 225 to reduce the light, the side window 219, the ventilation device 221 and the air conditioner 227 to perform ventilation or dehumidification, a sprinkling device and a mist. The watering by the device is used in combination.

The ceiling curtain 223 and the side curtain 225 not only suppress the rise in the internal temperature of the main body of the greenhouse VGH by dimming, but also suppress the strong light in summer, so that the photosynthesis of the plant PT can be efficiently performed. Can be expected.

The ventilation device 221 and the side window 219 ventilate by exhausting the air inside the main body of the vinyl house VGH and taking the outside air into the main body of the vinyl house VGH to raise the internal temperature of the main body of the vinyl house VGH. Suppress. In addition, the air conditioner 227 forms an air flow around the plant PT to promote the transpiration action of the plant PT (see later), and further reduces the humidity around the plant PT.

Further, the watering device and the mist device lower the temperature of the leaf PT3 by applying water having a temperature lower than the ambient temperature of the plant PT to the plant PT, and also deprive the heat of vaporization to lower the ambient temperature of the plant PT. It is used to The watering device mainly contributes to lowering the temperature of the leaf PT3 of the plant PT and the ambient temperature of the plant PT in the lower part of the main body of the greenhouse VGH. The mist device mainly contributes to reducing the temperature in the upper part of the main body of the greenhouse VGH.

When sprinkling water for the purpose of lowering the temperature of leaves, it is desirable to set the water temperature to about 10° C. by a chiller (not shown) in summer. Since the chiller requires a relatively long time until the water temperature reaches the set temperature, when using the chiller, consider the time until the water temperature reaches the set temperature and trace back from the timing of supplying water from the water supply device to the plant PT. It is necessary to adjust the temperature. In addition, when the temperature of the plant PT becomes low as in the winter, the water temperature may be set to about 15° C. by a chiller to raise the temperature of the leaves.

In the present embodiment, as described above, in order to control the environment of the plant PT, dimming by the ceiling curtain 223 and the side curtain 225, ventilation or dehumidification by the side window 219, the ventilation device 221, and the air conditioner 227, and a watering device. And the sprinkling with the mist device is used in combination.

The water sprinkling device and the mist device are mainly used for the purpose of supplying water to the plant PT and controlling the ambient temperature of the plant PT. Therefore, the control device 200 controls at least one of the timing and the amount of water sprayed by the water spray device and the mist device according to the ambient temperature and humidity of the plant PT measured by the environment sensor 211. The timing and amount of water sprayed with respect to the ambient temperature and humidity of the plant PT detected by the environment sensor 211 are determined in advance and stored in the storage unit 207.

In addition, the control device 30 controls the ventilation device 221 (including the air conditioner 227 as necessary) for the purpose of dehumidification, cooling, ventilation, etc. according to conditions such as temperature, humidity, and illuminance measured by the environment sensor 211. May be operated.

(Explanation of each part of the plant detection camera)
FIG. 3 is a block diagram showing an example of the internal configuration of the plant detection camera 1 in detail. The plant detection camera 1 shown in FIG. 3 has a configuration including a non-visible light sensor NVSS and a visible light camera VSC. The non-visible light sensor NVSS has a configuration including a control unit 11, a projection unit PJ, and an image determination unit JG. The projection unit PJ has a first projection light source 13, a second projection light source 15, and a projection light source scanning optical unit 17. The image determination unit JG includes an imaging optical unit 21, a light receiving unit 23, a signal processing unit 25, a detection processing unit 27, and a display processing unit 29. The visible light camera VSC has an imaging optical unit 31, a light receiving unit 33, an imaging signal processing unit 35, and a display control unit 37. The communication terminal MT is carried by a user (for example, a growth observer of a plant PT of fruit vegetables such as tomatoes. The same applies hereinafter).

In the description of each part of the plant detection camera 1, the control unit 11, the invisible light sensor NVSS, and the visible light camera VSC will be described in this order.

The control unit 11 is configured by using, for example, a CPU (Central Processing Unit), an MPU (Micro Processing Unit), or a DSP (Digital Signal Processor), and generally controls the operation of each unit of the visible light camera VSC and the invisible light sensor NVSS. Signal processing for overall control, data input/output processing with other units, data arithmetic processing, and data storage processing. The control unit 11 also includes a timing control unit 11a described later (see FIG. 4).

The control unit 11 sets the detection threshold value M of the plant PT to be detected by the invisible light sensor NVSS in the detection processing unit 27 described below. Details of the operation of the control unit 11 will be described later with reference to FIG.

The timing control unit 11a controls the projection timing of the first projection light source 13 and the second projection light source 15 in the projection unit PJ. Specifically, when the timing control unit 11a causes the first projection light source 13 or the second projection light source 15 to project the projection light, the timing control unit 11a outputs the light source scanning timing signal TR to the first projection light source 13 or the second projection light source 15. Output.

In addition, the timing control unit 11a alternately outputs the light source emission signal RF to the first projection light source 13 or the second projection light source 15 at the start of a predetermined projection cycle. Specifically, the timing controller 11a outputs the light source light emission signal RF to the first projection light source 13 at the start of the odd-numbered projection cycle, and outputs the light source emission signal RF at the second projection light source at the start of the even-numbered projection cycle. Output to 15.

Next, each part of the invisible light sensor NVSS will be described.

When the first projection light source 13 as an example of the first light source receives the light source scanning timing signal TR from the timing control unit 11a of the control unit 11, the first projection light source 13 outputs from the timing control unit 11a for each odd-numbered projection cycle (default value). The reference light LS1 (for example, near-infrared light), which is a laser beam of invisible light having a predetermined wavelength (for example, 905 nm), is transmitted through the projection light source scanning optical unit 17 in accordance with the light source emission signal RF of Project on PT.

The presence/absence of detection of water in the plant PT may be determined by comparing it with a predetermined detection threshold M. The detection threshold M may be a predetermined value or an arbitrarily set value, and a value based on the intensity of diffuse reflection light acquired in the absence of water (for example, in the absence of water). A value obtained by adding a predetermined margin to the acquired intensity value of diffuse reflected light) may be used. That is, the presence/absence of water detection may be determined by comparing the detection result image data acquired in the absence of water with the detection result image data acquired thereafter. In this way, by acquiring the intensity of the diffusely reflected light in the absence of water, a threshold suitable for the environment in which the plant detection camera 1 is installed can be set as the detection threshold M for the presence or absence of water.

When the second projection light source 15 as an example of the second light source receives the light source scanning timing signal TR from the timing control unit 11a of the control unit 11, the second projection light source 15 outputs from the timing control unit 11a for every even-numbered projection cycle (default value). The measurement light LS2 (for example, infrared light), which is invisible laser light having a predetermined wavelength (for example, 1550 nm) according to the light source emission signal RF of the plant PT, is transmitted through the projection light source scanning optical unit 17. To project. In the present embodiment, the measurement light LS2 projected from the second projection light source 15 is used to determine whether or not water is detected in the plant PT. The wavelength 1550 nm of the measurement light LS2 has a characteristic that it is easily absorbed by water (see FIG. 7).

Furthermore, the plant detection camera 1 uses the diffuse reflection light RV1 of the reference light LS1 as reference data for detecting water at the irradiation position of the plant PT, and the diffuse reflection light at the irradiation position of the plant PT irradiated with the measurement light LS2. The presence or absence of water at the irradiation position of the plant PT irradiated with the reference light LS1 and the measurement light LS2 is detected using RV2 and the diffuse reflection light RV1 of the reference light LS1. Therefore, the plant detection camera 1 uses the reference light LS1 and the measurement light LS2 of two different wavelengths and their diffuse reflection lights RV1 and RV2 to detect water in the plant PT with high accuracy. Can be detected.

The projection light source scanning optical unit 17 projects the reference light LS1 projected from the first projection light source 13 or the measurement light LS2 projected from the second projection light source 15 onto the plant PT existing in the detection area of the invisible light sensor NVSS. Are two-dimensionally scanned. Thereby, the plant detection camera 1 irradiates the reference light LS1 and the measurement light LS2 on the basis of the diffuse reflection light RV2 in which the measurement light LS2 is reflected at the irradiation position of the plant PT and the above-described diffuse reflection light RV1. It is possible to detect the presence or absence of water at the irradiation position of.

Next, the internal configuration of the image determination unit JG will be described in detail with reference to FIGS. 3 and 4. FIG. 4 is a diagram showing in detail an example of the internal configuration of the image determination unit JG of the plant detection camera 1.

The imaging optical unit 21 is configured using, for example, a lens, collects light (for example, diffuse reflection light RV1 or diffuse reflection light RV2) incident from the outside of the plant detection camera 1, and diffuses reflection light RV1 or diffuse reflection light RV2. Is imaged on a predetermined imaging surface of the light receiving unit 23.

The light receiving unit 23 is an image sensor having a peak of spectral sensitivity with respect to both wavelengths of the reference light LS1 and the measurement light LS2. The light receiving unit 23 converts an optical image of the diffuse reflected light RV1 or the diffuse reflected light RV2 formed on the imaging surface into an electric signal. The output of the light receiving unit 23 is input to the signal processing unit 25 as an electric signal (current signal). The imaging optical unit 21 and the light receiving unit 23 have a function as an imaging unit in the invisible light sensor NVSS.

The signal processing unit 25 has an I/V conversion circuit 25a, an amplification circuit 25b, and a comparator/peak hold processing unit 25c. The I/V conversion circuit 25a converts a current signal, which is an output signal (analog signal) of the light receiving unit 23, into a voltage signal. The amplifier circuit 25b amplifies the level of the voltage signal that is the output signal (analog signal) of the I/V conversion circuit 25a to a level that can be processed by the comparator/peak hold processing section 25c.

The comparator/peak hold processing unit 25c binarizes the output signal of the amplification circuit 25b according to the result of comparison between the output signal (analog signal) of the amplification circuit 25b and a predetermined threshold value, and sets the threshold value/moisture index detection processing unit. 27a. The comparator/peak hold processing unit 25c includes an ADC (Analog Digital Converter), detects and holds the peak of the AD (Analog Digital) conversion result of the output signal (analog signal) of the amplifier circuit 25b, and further holds the peak. Is output to the threshold setting/moisture index detection processing unit 27a.

The detection processing unit 27 includes a threshold value setting/water content index detection processing unit 27a, a memory 27b, and a detection result filter processing unit 27c. The threshold setting/moisture index detection processing unit 27a creates and registers frequency distribution data in advance. The frequency distribution data indicates the frequency distribution of the reflection intensity ratio in all the pixels of one frame image. As will be described later, the threshold setting/moisture index detection processing unit 27a, which is an example of the threshold calculation unit, calculates and sets the threshold Sh of the reflection intensity ratio for identifying the shape of the leaf using this frequency distribution data. To do.

Further, the threshold value setting/moisture index detection processing unit 27a outputs the output (peak information) of the comparator/peak hold processing unit 25c in the diffuse reflection light RV1 of the reference light LS1 and the comparator/peak in the diffuse reflection light RV2 of the measurement light LS2. The presence or absence of water at the irradiation position of the reference light LS1 and the measurement light LS2 of the plant PT is detected based on the output (peak information) of the hold processing unit 25c.

Specifically, the threshold value setting/moisture index detection processing unit 27a temporarily stores the output (peak information) of the comparator/peak hold processing unit 25c in the diffuse reflected light RV1 of the reference light LS1 in the memory 27b, Next, the process waits until the output (peak information) of the comparator/peak hold processing unit 25c in the diffuse reflection light RV2 of the measurement light LS2 is obtained. The threshold value setting/moisture index detection processing unit 27a refers to the memory 27b after obtaining the output (peak information) of the comparator/peak hold processing unit 25c in the diffuse reflection light RV2 of the measurement light LS2, Output (peak information) of the comparator/peak hold processing unit 25c in the diffuse reflection light RV1 of the reference light LS1 in the same line of the plant PT included in the above and the comparator/peak hold processing unit 25c in the diffuse reflection light RV2 of the measurement light LS2. Calculate the ratio with the output (peak information).

For example, at the irradiation position where water is present, part of the measurement light LS2 is easily absorbed, so the reflection efficiency at that irradiation position is reduced, and the intensity (that is, amplitude) of the diffuse reflection light RV2 is attenuated. Therefore, the threshold setting/moisture index detection processing unit 27a calculates the calculation result (for example, the difference between the intensities of the diffuse reflected light RV1 and the diffuse reflected light RV2 (amplitude difference ΔV)) for each line of the plant PT included in the angle of view. The presence or absence of water at the irradiation position of the reference light LS1 and the measurement light LS2 can be detected based on the calculation result or the intensity ratio of the diffuse reflected light RV1 and the diffuse reflected light RV2).

The threshold value setting/water content index detection processing unit 27a has an amplitude difference (VA-VB) between the amplitude VA of the diffuse reflected light RV1 of the reference light LS1 and the amplitude VB of the diffuse reflected light RV2 of the measurement light LS2, and the amplitude VA. The presence/absence of water at the irradiation position of the reference light LS1 and the measurement light LS2 of the plant PT may be detected according to the comparison of the ratio RT of the above and the predetermined detection threshold M (see FIG. 6).

Further, the threshold value setting/moisture index detection processing unit 27a calculates an intensity ratio of the diffuse reflection light RV1 and the diffuse reflection light RV2, that is, a reflection intensity ratio (also referred to as a measurement value) Ln (I ₉₀₅ /I ₁₅₅₀ ), and this reflection From the sum of the intensity ratios Ln(I ₉₀₅ /I ₁₅₅₀ ), the sum of water indexes corresponding to the amount of water contained in the leaves is obtained. The reflection intensity ratio Ln(I ₉₀₅ /I ₁₅₅₀ ) is, for example, all the pixels forming one frame of the visible light image captured by the visible light camera VSC or 1 of the invisible light image obtained by the invisible light sensor NVSS. For all the pixels that make up the frame, for example, it is calculated for each predetermined number of pixels (1×1 pixel, 4×4 pixels), and is expressed as the reflection intensity ratio W1 to Wk for each predetermined number of pixels.

The memory 27b is configured using, for example, a RAM (Random Access Memory), and temporarily stores the output (peak information) of the comparator/peak hold processing unit 25c in the diffuse reflection light RV1 of the reference light LS1.

The detection result filter processing unit 27c extracts information regarding the detection result of water from the plant detection camera 1 after filtering extra components such as noise based on the output of the threshold value setting/water content index detection processing unit 27a. The detection result filter processing unit 27c outputs information regarding the extraction result to the display processing unit 29. For example, the detection result filter processing unit 27c outputs, to the display processing unit 29, information regarding the detection result of water at the irradiation position of the reference light LS1 and the measurement light LS2 of the plant PT.

The display processing unit 29 uses the output of the detection result filter processing unit 27c, and as an example of the information regarding the water content at the irradiation position, a non-visible light image indicating the position of the water content at the irradiation position for each distance from the plant detection camera 1 ( (Detection result image) data is generated. The display processing unit 29 outputs the detection result image data including the information on the distance from the plant detection camera 1 to the irradiation position to the display control unit 37 of the visible light camera VSC. The invisible light image may not include information on the distance from the plant detection camera 1 to the irradiation position.

Next, each part of the visible light camera VSC will be described. The imaging optical unit 31 is configured using, for example, a lens, collects the ambient light RV0 from within the view angle of the plant detection camera 1, and forms an image of the ambient light RV0 on a predetermined imaging surface of the light receiving unit 33.

The light receiving unit 33 is an image sensor having a peak of spectral sensitivity with respect to the wavelength of visible light (for example, 0.4 μm to 0.7 μm). The light receiving unit 33 converts the optical image formed on the imaging surface into an electric signal. The output of the light receiving unit 33 is input to the imaging signal processing unit 35 as an electric signal. The imaging optical unit 31 and the light receiving unit 33 have a function as an imaging unit in the visible light camera VSC.

The image pickup signal processing unit 35 uses the electric signal output from the light receiving unit 33 to generate visible light image data defined by RGB (Red Green Blue) or YUV (luminance/color difference) that can be recognized by a person. .. As a result, the visible light image data captured by the visible light camera VSC is formed. The imaging signal processing unit 35 outputs visible light image data to the display control unit 37.

The display control unit 37 uses the visible light image data output from the imaging signal processing unit 35 and the detection result image data output from the display processing unit 29 to determine whether water is present at any position of the visible light image data. When detected, as an example of the information regarding the water content, display data in which visible light image data and detection result image data are combined, or display data in which the visible light image data and the detection result image data are displayed in a comparable manner is generated. To do. The display control unit 37 (output unit) transmits the display data to, for example, the data logger DL or the communication terminal MT connected via the network to prompt the display.

The data logger DL transmits the display data output from the display control unit 37 to the communication terminal MT or one or more external connection devices (not shown), and the communication terminal MT or one or more external connection devices (for example, FIG. 1). The display data on the display screen of the monitor 50) in the office control room shown in FIG.

The communication terminal MT is, for example, a portable communication terminal used by an individual user, receives the display data transmitted from the display control unit 37 via a network (not shown), and displays the display screen (not shown) of the communication terminal MT. Display data is displayed on the display screen.

(Description of an example of the initial operation in the control unit of the invisible light sensor)
Next, an example of an initial operation in the control unit 11 of the non-visible light sensor NVSS of the plant detection camera 1 according to the present embodiment will be described with reference to FIG. FIG. 5 is a flowchart illustrating an example of an initial setting operation in the control unit 11 of the plant detection camera 1.

When the control unit 11 instructs the threshold setting/moisture index detection processing unit 27a to set the threshold Sh of the reflection intensity ratio for identifying the leaf shape, the threshold setting/moisture index detection processing unit 27a causes the threshold Sh Is calculated and set (S1). Details of the process of setting the threshold Sh will be described later with reference to FIGS. 28 to 30, for example. When the threshold Sh is a fixed value, the process of step S1 can be omitted.

The control unit 11 sets the moisture detection threshold M in the detection processing unit 27 of the invisible light sensor NVSS in the threshold setting/moisture index detection processing unit 27a (S2). It is preferable that the detection threshold M be appropriately set according to the plant to be detected.

After the process of step S2, the control unit 11 outputs a control signal for starting the imaging process to each unit of the visible light camera VSC (S3-1). Further, the control unit 11 outputs the light source scanning timing signal TR for causing the first projection light source 13 or the second projection light source 15 to start the projection of the reference light LS1 or the measurement light LS2 to the first projection light source of the non-visible light sensor NVSS. 13 or the second projection light source 15 (S3-2). In addition, the execution timing of the operation of step S3-1 and the operation of step S3-2 may be earlier, or may be simultaneous.

FIG. 6 is an explanatory diagram of the principle of detecting moisture in the invisible light sensor NVSS. The threshold value setting/moisture index detection processing unit 27a may determine that moisture is detected if RT>M, and may determine that moisture is not detected if RT≦M. In this way, the threshold setting/moisture index detection processing unit 27a detects the presence or absence of water according to the comparison result of the ratio RT of the amplitude difference (VA-VB) and the amplitude VA and the detection threshold M. The influence of noise (for example, ambient light) can be eliminated, and the presence or absence of water can be detected with high accuracy.

FIG. 7 is a graph showing an example of spectral characteristics of near infrared light with respect to water (H ₂ O). The horizontal axis of FIG. 7 represents wavelength (nm), and the vertical axis of FIG. 7 represents transmittance (%). As shown in FIG. 7, the reference light LS1 having a wavelength of 905 nm has a characteristic that the transmittance of water (H ₂ O) is almost 100%, and thus the reference light LS1 is difficult to be absorbed by water. Similarly, the measurement light LS2 having a wavelength of 1550 nm has a property of being easily absorbed by water because the transmittance of water (H ₂ O) is close to 10%. Therefore, in the present embodiment, the wavelength of the reference light LS1 projected from the first projection light source 13 is 905 nm, and the wavelength of the measurement light LS2 projected from the second projection light source 15 is 1550 nm.

In the case where the projection range of near-infrared light is reduced due to the wilting of the leaf, or even when the thickness of the leaf is increased by curving or curling the leaf, the present embodiment constitutes a non-visible light image of the leaf. An average value obtained by dividing the total sum of reflection intensity ratios in all pixel regions (that is, each pixel) by the number of pixels (hereinafter, referred to as “pixel average moisture index”) and a leaf invisible light image are formed. The sum of the reflection intensity ratios of all the pixels (hereinafter, referred to as “sum of water index”) is used as an index of the amount of water. Further, the normalized average pixel moisture index (or simply “moisture content”) is shown by normalizing the pixel average moisture index value and the total moisture index value when water stress is not applied (that is, at the initial stage) to 1.0. Index)) and the standardized moisture index sum. In this way, by expressing the relative value with the initial value set to 1.0, it is possible to easily make a temporal change in the “pixel average moisture index” and the “total moisture index” between leaves having different angles and leaf thicknesses. Can be compared. The pixel average moisture index and the sum of moisture indices are calculated using the reflection intensity ratio calculated for each pixel that constitutes the invisible light image of the leaf. Therefore, the pixel average moisture index is represented by “(1/the number of pixels forming the invisible light image of the leaf)×ΣLn(I ₉₀₅ /I ₁₅₅₀ )”, and the total moisture index is “ΣLn(I ₉₀₅ /I _{1550 ).} )”, and each has a strong correlation with the water potential (in other words, the amount of water stress applied to the plant). Note that all the pixel regions forming the invisible light image of the leaf have pixel values (that is, reflection intensity ratios of pixels corresponding to positions irradiated with the reference light LS1 and the measurement light LS2) at the beginning of the measurement period, for example. A value is a set of regions in which the value exceeds the threshold Sh. The threshold value Sh may be a preset value or may be calculated according to the method shown in FIG. 29 described later.

(Detailed description of the operation of the invisible light sensor for detecting moisture)
Next, a detailed operation procedure regarding the detection of moisture in the invisible light sensor NVSS of the plant detection camera 1 will be described with reference to FIG. FIG. 8 is a flowchart illustrating an example of a detailed operation procedure regarding detection of water contained in the leaf PT3 of the plant PT in the non-visible light sensor NVSS. As a premise of the description of the flowchart shown in FIG. 8, the timing control unit 11a outputs the light source scanning timing signal TR to the first projection light source 13 or the second projection light source 15, and the plant detection camera 1 outputs the reference light LS1 or It is assumed that the measurement light LS2 is emitted toward the leaf PT3 of the plant PT.

In FIG. 8, the control unit 11 determines whether the light source emission signal RF in the odd-numbered projection cycle is output from the timing control unit 11a (S12). When the light source emission signal RF in the odd-numbered projection cycle is output from the timing control unit 11a (S12, YES), the first projection light source 13 refers to the light source emission signal RF from the timing control unit 11a. The light LS1 is projected (S13). The projection light source scanning optical unit 17 one-dimensionally scans the X-direction line of the plant PT included in the angle of view of the plant detection camera 1 with the reference light LS1 (S15). At each irradiation position on the line in the X direction irradiated with the reference light LS1, diffuse reflection light RV1 generated by diffuse reflection of the reference light LS1 is received by the light receiving unit 23 via the imaging optical unit 21 ( S16).

In the signal processing unit 25, the output (electrical signal) of the diffuse reflected light RV1 in the light receiving unit 23 is converted into a voltage signal, and the level of this voltage signal is amplified to a level that can be processed in the comparator/peak hold processing unit 25c ( S17). The comparator/peak hold processing unit 25c binarizes the output signal of the amplification circuit 25b and outputs the binarized output signal to the threshold value setting/moisture index detection processing unit 27a according to the result of comparison between the output signal of the amplification circuit 25b and a predetermined threshold value. .. The comparator/peak hold processing unit 25c outputs the information on the peak of the output signal of the amplifier circuit 25b to the threshold setting/moisture index detection processing unit 27a.

The threshold value setting/moisture index detection processing unit 27a temporarily stores the output (peak information) of the comparator/peak hold processing unit 25c for the diffuse reflection light RV1 of the reference light LS1 in the memory 27b (S18-2). Further, the threshold value setting/moisture index detection processing unit 27a uses the comparator/related to the same line in the diffuse reflected light RV1 or the diffuse reflected light RV2 with respect to the reference light LS1 or the measurement light LS2 in the previous frame (projection cycle) stored in the memory 27b. The output of the peak hold processing unit 25c is read from the memory 27b (S18-3).

The threshold value setting/moisture index detection processing unit 27a uses the comparator/output of the peak hold processing unit 25c (peak information) for the diffuse reflection light RV1 of the reference light LS1 and the comparator/the diffuse reflection light RV2 of the measurement light LS2 for the same line/ The presence or absence of water on the same line is detected based on the output (peak information) of the peak hold processing unit 25c and a predetermined detection threshold M (S18-4).

The threshold value setting/moisture index detection processing unit 27a, which is an example of the moisture amount calculation unit, calculates a moisture index that is the sum ΣLn(I ₉₀₅ /I ₁₅₅₀ ) of the reflection intensity ratios (S18-5). Details of the calculation of the moisture index will be described later.

The display processing unit 29 uses the output of the detection result filter processing unit 27c to generate detection result image data indicating the detection position of water. The display control unit 37 outputs the detection result image data generated by the display processing unit 29 and the visible light camera image data of the visible light image captured by the visible light camera VSC (S19). The operations of steps S15, S16, S17, S18-2 to S18-5, and S19 are executed for each line in the detection area of one frame (projection cycle).

That is, when the operations of steps S15, S16, S17, S18-2 to S18-5 and S19 for one line in the X direction are completed, steps S15, S16, S17 and S18-2 to the next line in the X direction are completed. The operations of S18-5 and S19 are performed (S20, NO), and thereafter, until the operations of steps S15, S16, S17, S18-2 to S18-5, and S19 for one frame are completed, step S15, The operations of S16, S17, S18-2 to S18-5, and S19 are repeated.

On the other hand, when the execution of the operations of steps S15, S16, S17, S18-2 to S18-5, and S19 is completed for all the lines of one frame (S20, YES), the scanning of the projection light is continued. If yes (S21, YES), the operation of the non-visible light sensor NVSS returns to step S12. On the other hand, when the scanning of the reference light LS1 and the measurement light LS2 is not continued (S21, NO), the operation of the invisible light sensor NVSS ends.

FIG. 9 is a flowchart illustrating an example of the calculation procedure of the moisture index in step S18-5. The threshold value setting/moisture index detection processing unit 27a calculates the reflection intensity ratio Ln(I ₉₀₅ /I ₁₅₅₀ ) in all pixels from one frame of the detection result image data which is invisible light image data (S31). Here, the measured value of the reflection intensity ratio Ln (I ₉₀₅ /I ₁₅₅₀ ) of each pixel is represented by the reflection intensity ratios W1 to Wk. For example, when the image of near infrared light is composed of 76,800 (=320×240) pixels, the subscript k of Wk is a variable representing 1 to 76,800.

The threshold setting/moisture index detection processing unit 27a determines whether or not the reflection intensity ratio Wk for each pixel is larger than a threshold Sh for identifying the leaf PT3 (S32). The initial value of the threshold value Sh is registered in advance in the threshold value setting/water content index detection processing unit 27a as an empirical value. The experience value depends on the specifications of the water content observation device (intensity of irradiation laser light, sensitivity of light receiving element, etc.), water content of leaf to be measured (around 90%), leaf thickness (for example, 200 μm), indoor/outdoor etc. It is determined. In particular, in the case of outdoors, it changes depending on how the sunlight hits and the degree of thickening as a leaf group, and is changed each time.

For example, as an empirical value, when the shooting distance is 1 m, the threshold Sh for indoor shooting is set to about 0.3. The threshold value Sh for outdoor shooting is set to about 0.9. When the shooting distance is 3 m, the threshold Sh for indoor shooting is set to about 0.05. It is preferable to set these threshold values Sh as initial values, check with the actual shape of the leaves to determine whether they are optimal, and change the threshold values Sh if they are not optimal. Further, as will be described later, it is possible to perform a threshold Sh calculation process and register the calculated threshold Sh as an initial value.

When the reflection intensity ratio Wk is less than the threshold value Sh in step S32, the display processing unit 29 determines that this pixel is a pixel representing a background other than the leaves, and the display processing unit 29 displays the monochrome display data for displaying the pixel in monochrome. Generate (S36).

On the other hand, when the reflection intensity ratio Wk is greater than or equal to the threshold value Sh (more than or equal to the threshold value) in step S32, the display processing unit 29 displays this pixel in a gradation color corresponding to the reflection intensity ratio Ln(I ₉₀₅ /I ₁₅₅₀ ). Yes (S33). Here, the gradation color corresponding to the reflection intensity ratio Ln (I ₉₀₅ /I ₁₅₅₀ ) can be displayed in n gradations. n is an arbitrary positive number.

Specifically, when the reflection intensity ratio Ln(I ₉₀₅ /I ₁₅₅₀ ) is less than 0.3, that is, when it is equal to or less than the leaf threshold Sh, the pixel is displayed in white (single color), for example. On the other hand, when the reflection intensity ratio Ln(I ₉₀₅ /I ₁₅₅₀ ) is 0.3 or more and less than 0.4, the pixel is displayed in, for example, dark green. Similarly, when it is 0.4 or more and less than 0.5, the pixel is displayed in green. If it is 0.5 or more and less than 0.55, the pixel is displayed in yellow. When it is 0.55 or more and less than 0.6, the pixel is displayed in orange. If it is greater than or equal to 0.6 and less than 0.75, the pixel is displayed in red. If it is 0.75 or more, the pixel is displayed in purple. In this way, the color of the pixel belonging to the leaf is set to any of the 6 gradations.

If the pixel space occupied by the leaves is not appropriate in comparison with the actual shape of the leaves, the user may set the threshold value Sh up or down at predetermined intervals (for example, 0.01). Good. Alternatively, the user may activate a process for automatically setting a threshold value Sh, which will be described later, and set an appropriate threshold value Sh.

The threshold setting/moisture index detection processing unit 27a identifies an arbitrary area as the pixel space occupied by the leaves (S34). The leaf pixel is a pixel whose reflection intensity ratio Ln (I ₉₀₅ /I ₁₅₅₀ ) exceeds the threshold value Sh (here, 0.3). Also, a rectangular (A×B) area ARE is specified so as to surround the leaf pixels. This area ARE is used as a value for determining the leaf size. The leaf size may be represented by the number of pixels exceeding the threshold Sh.

In the area ARE, the threshold value setting/moisture index detection processing unit 27a determines that the measured value (reflected intensity ratio Ln(I ₉₀₅ /I ₁₅₅₀ )) is larger than the threshold Sh and the reflected intensity ratio Ln(I ₉₀₅ /I ₁₅₅₀ ). The sum of the water content indexes ΣLn(I ₉₀₅ /I ₁₅₅₀ ) is calculated (S35). By obtaining this sum of water index ΣLn(I ₉₀₅ /I ₁₅₅₀ ), the amount of water contained in the entire leaf can be known.

Further, in step S35, the threshold setting/moisture index detection processing unit 27a calculates the number of pixels in the area ARE whose measured value (reflection intensity ratio Ln(I ₉₀₅ /I ₁₅₅₀ )) is larger than the threshold Sh, An average value (referred to as a pixel average moisture index) can be calculated by dividing the total sum ΣLn(I ₉₀₅ /I ₁₅₅₀ ) of the reflection intensity ratios by the calculated number of pixels. This average value is a value obtained by dividing the sum of the reflection intensity ratios by the area of the leaf whose outer shape is determined by the threshold value Sh, and the value obtained by dividing the sum of the reflection intensity ratios within the spot by the constant area of the spot. Is different from. After that, the operation of calculating the moisture index is completed.

Thus, in the present embodiment, instead of obtaining the reflection intensity ratio for each irradiation position, the reflection intensity ratio for each pixel in the frame image is obtained, and the moisture index can be accurately calculated from the sum of the reflection intensity ratios for each pixel. .. Therefore, the soundness of the leaves, that is, the plant can be accurately determined.

Here, as described above, the leaf threshold Sh is set to the following value as an initial value. When the plant detection camera 1 is installed indoors and the leaf PT3 is imaged indoors, and the empirical shooting distance is 1 m, the threshold Sh is set to about 0.3. When the shooting distance is 3 m, the threshold Sh is set to about 0.05. On the other hand, when an image is taken outdoors (for example, in a greenhouse VGH), the condition of external light (for example, sunlight) changes, so the threshold Sh is empirically set to about 0.9. FIG. 28 is a diagram showing a leaf occupation range. FIG. 28A is a frame image in which the foliage of tomato is imaged. The distance between leaves is about 1 cm. FIG. 28B shows the occupied space of the leaves obtained when the shooting distance is set to 3 m and the threshold value Sh is set to 0.05 with respect to the visible light image of FIG. In this case, it can be seen that the leaves partially overlap and the threshold value Sh (=0.05) is an inappropriately set value. FIG. 28C shows the leaf occupying space obtained when the photographing distance is set to 1 m and the threshold value Sh is set to 0.3 with respect to the visible light image of FIG. 28A. In this case, the outer shape of the leaf does not overlap with other leaves, and the occupied space of the leaf is roughly the same as the outer shape of the leaf of the visible light image. In this case, it can be seen that the threshold value Sh (=0.3) is a correctly set value.

Further, the leaf threshold Sh may be registered before performing the following process and performing the process of calculating the moisture index shown in FIG. FIG. 29 is a flowchart illustrating an example of a threshold setting procedure.

The threshold value setting/moisture index detection processing unit 27a appears in a frame image captured by the visible light camera VSC (see, for example, FIG. 28A) occupied by green (G) pixels that are determined to be leaf colors. The ratio (number of G pixels/total number of pixels) is calculated (S101).

The threshold value setting/moisture index detection processing unit 27a obtains a moisture index corresponding to the appearance rate based on the frequency distribution data of the moisture index (S102). FIG. 30 is a graph showing a frequency distribution of reflection intensity ratios in all pixels. The frequency distribution data is registered in the threshold setting/moisture index detection processing unit 27a. Using this frequency distribution data, for example, when the appearance ratio occupied by the green (G) pixels determined to be the color of leaves is 52%, the moisture index is about 0.3.

The threshold value setting/water content index detection processing unit 27a sets the water content index obtained in step S102 as the threshold value Sh (S103). Then, the threshold value setting/moisture index detection processing unit 27a ends this processing.

As described above, by using the visible light image captured by the visible light camera VSC, the measured value Ln(I ₉₀₅ / The outer shape of the leaf can be correctly determined by obtaining the threshold value Sh corresponding to the cumulative frequency of I ₁₅₅₀ ), that is, by changing the threshold value of the water content for each pixel that is determined to be included in the leaf. it can. Therefore, by correctly determining the outer shape of the leaf, the average value in pixel units can be accurately calculated. On the other hand, in the case of using the fixed area of the spot or the outer shape of the visible light image, if the outer shape of the leaf is not correctly captured, a large error will occur in the average value in pixel units.

Here, a comparative example will be described with respect to another method of measuring the water content in the leaves. FIG. 10: is a figure explaining an example of the measuring method of a comparative example. The leaf PT3 of the large leaf which is hermetically packaged in the vinyl bag fk is taken out and fixed on the white board wb so that the leaf PT3 does not move. The white board wb to which the leaf PT3 is firmly fixed is placed on the weight scale gm, and its weight is measured. At this time, since the weight of the whiteboard wb is measured in advance and adjusted to 0 point, the weight of the leaf is displayed on the meter of the weighing scale gm. The change in weight due to leaf transpiration is measured over time. After completing all measurements, the leaves are completely killed and their weight is determined. By deducting the leaf weight at the time of depletion from the leaf weight at the time of measurement, the average water content of the leaf at the time of measurement is obtained. The average leaf water content gradually decreases over time.

On the other hand, in the present embodiment, when measuring the water content of the leaf, the background object is arranged so as to cover the back surface (back side) of the leaf to be measured. Examples of the material of the background material include those which do not contain water and which are not deformed by pesticides, water sprinkling and CO2 spray, for example, plastic, coated paper, sheets such as aluminum foil (plate), plates, or blocks. Further, the size of the background object is such that it has a large surface that covers the leaves to be measured, is within twice the projected area of the leaves to be measured, and does not interfere with photosynthesis of other leaves. Is desirable. The thickness of the background material is 50 μm to 1 mm, which is self-supporting and does not curl, and particularly preferably 50 to 200 μm. In addition, the weight of the background material is preferably such that the leaves do not wither when they are supported by the stems of the leaves. Further, the color of the background material is preferably white or silver which has a high reflectance for visible light and near infrared light.

In this embodiment, a case where a white background plate is used as the background object is shown. Examples of the white background plate include a white plastic plate, an aluminum plate, a standard white plate, and white paper.

FIG. 11A is a graph showing an example of the intensity of the reflected light with respect to the wavelength of the near-infrared light when the near-infrared light is applied to the leaves outdoors. The vertical axis represents the intensity of near infrared light detected by the invisible light sensor NVSS, and the horizontal axis represents the wavelength in the near infrared region. The intensity of near-infrared light detected by the non-visible light sensor NVSS includes the intensity of light from sunlight and the intensity of light scattered by surrounding leaves. That is, the detected intensity of near-infrared light includes the amount of rise in the background due to the multiple scattering of sunlight by the leaves in the vicinity. In addition, since the near-infrared light having a wavelength of 1550 nm is absorbed by the leaves around it, the intensity of light detected by the non-visible light sensor NVSS becomes small. Therefore, the value of the reflection intensity ratio Ln(I ₉₀₅ /I ₁₅₅₀ ) becomes large. Therefore, when measuring the water content of leaves outdoors, it is necessary to set a large value for the threshold value Sh that is compared with the reflection intensity ratio Ln(I ₉₀₅ /I ₁₅₅₀ ).

FIG. 11B is a graph showing an example of the intensity of the reflected light with respect to the wavelength of the near-infrared light when the near-infrared light is applied to the leaves on which the white background plate bd is installed indoors and outdoors. .. The vertical axis represents the intensity of near infrared light detected by the invisible light sensor NVSS, and the horizontal axis represents the wavelength in the near infrared region. Since the white background plate bd is arranged so as to cover the back surface (back side) of the measurement target leaf PT3t, multiple scattering from the peripheral leaf PT3o does not occur. Therefore, the intensity of near infrared light having a wavelength of 1550 nm does not decrease. Further, in the case of indoors, the background does not rise. It should be noted that the threshold value Sh is set to about 0.5 when measuring outdoors. Moreover, when measuring indoors, the threshold value Sh is set to about 0.3.

When the white background plate bd is arranged on the back surface of the leaf PT3t to be measured, the leaves may be arranged without being fixed, or the leaf PT3t may be attached and fixed to the white background plate bd. Here, the case where the leaf PT3t is attached to the white background plate bd is shown. In addition, in each embodiment including this embodiment, the white background plate bd is provided on the back surface of at least one leaf to be measured when viewed from the first projection light source 13 and the second projection light source 15 of the plant detection camera 1. Are arranged respectively.

FIG. 12 is an explanatory diagram of an example of how to attach the leaf PT3t to the white background plate bd. The white background plate bd is a white plastic plate having a vertically long rectangle. At the center of the white background board bd, an opening bd1 is formed that is hollowed out in a rectangular shape. In addition, a circular hole portion bd2 is formed in the upper part of the white background plate bd. A slit bd21 reaching the upper end surface is formed in the hole portion bd2. Further, three slits bd3, bd4, and bd5 are formed below and on both sides of the opening bd1 formed in the white background plate bd.

When the leaf PT3t is attached to the white background board bd, the tip of the leaf PT3t is inserted into one of the three slits bd3, and the left and right white background boards bd are shifted in the front-rear direction around the slit bd21 to form a gap. The stem PT2 of the leaf is passed inside, and the stem PT2 is fixed to the hole portion bd2.

Next, as an observation of the amount of water contained in the leaves of the plant PT using the plant detection camera 1 of the present embodiment, a control experiment of the water potential contained in the leaves was carried out, and the result showed that Consider the sugar content of.

FIG. 13 is a graph showing an example of a temporal change of the standardized pixel average moisture index Dw in the first water potential control experiment. The vertical axis of this graph represents the standardized pixel average moisture index. The standardized pixel average moisture index represents the water potential as an index of the amount of moisture contained in the leaf to be measured, and is 1 in the invisible light image of the plant leaf (that is, the detection result image output from the display processing unit 29). The average water content in the leaf contained per pixel is shown. The horizontal axis of the graph represents the elapsed time in days. The target range Bd as an example of the target water content range represents a target water content range that is determined to be suitable for increasing the sugar content of the tomato fruit, for example, and here, the standardized pixel average water index is used. The value corresponding to Dw is set in the range of 0.8 to 0.9. The target range Bd varies depending on the type of plant, and even the same plant, depending on its observation location (leaf, stem, etc.). Further, in FIG. 13 and FIG. 14 described later, when the standardized pixel average moisture index Dw is below the target range Bd, the plant feels water stress.

The first water potential control experiment shown in FIG. 13 shows an example of a time-series transition of the standardized pixel average water index when an approximately appropriate amount of irrigation is performed at the irrigation timing. In FIG. 13, the state in which the leaf that is the plant sample sm1 is withered is the starting point, and the water potential control experiment has started after the normal irrigation and recovery. In normal irrigation, regular irrigation was performed twice a day, morning and evening. On the other hand, in the water potential control experiment, only the irrigation is performed at the timing determined to be appropriate based on the value of the standardized pixel average moisture index Dw, and the regular irrigation is not performed. Hereinafter, the experimental results shown in FIG. 13 will be described. The monitor 50 displays the time-dependent transition of the standardized pixel average moisture index Dw shown in FIG.

The standardized pixel average water content index Dw of the leaves starts from a withered state close to a value of 0.60, and normal watering is started (day 0). On the next day after the start of the normal irrigation, the standardized pixel average water index Dw of the leaves recovered until the value was around 1.0. Then, for about one week, regular irrigation was regularly performed so that the standardized pixel average water content index Dw of the leaves was maintained at a value of around 1.0 (1st to 8th days). The water was cut off for the next 3 days (9th, 10th and 11th days). As a result of the lack of water, the standardized pixel average water index Dw of the leaves gradually decreased until it reached a value of around 0.7 (day 12).

At this point, as shown by an arrow r11, when a certain amount of watering is performed, the standardized pixel average water content index Dw in the leaves rises and its peak is once included in the target range Bw. Based on this, it descends and goes out of the target range Bw. When the same fixed amount of irrigation is performed again at the timing shown by the arrow r12, the standardized pixel average water content index Dw in the leaves rises again, and after its peak enters the target range Bw, it falls based on unirrigation. .. At this time, the standardized pixel average moisture index Dw falls below the target range Bw, but the deviation amount is smaller than the previous time. When the same fixed amount of irrigation is performed again at the timing shown by the arrow r13, the peak of the standardized pixel average moisture index Dw falls after exceeding the upper limit of the target range Bw, but this time the standardized pixel average moisture index Dw is targeted. It does not fall below the range Bw. Further, when the same fixed amount of watering is performed at the timing shown by the arrow r14, the peak of the standardized pixel average moisture index Dw drops after exceeding the upper limit value of the target range Bw, but the standardized pixel average moisture index Dw is almost the target. Stay in the range Bw (12th to 16th days).

Even if there was water depletion for the subsequent 2 days (17th and 18th days), as shown by arrows r15, r16, r17, and r18, the same irrigation was performed, and thus the standardized pixel mean water index in the leaves was obtained. Dw was controlled so as to be almost within the target range Bw.

FIG. 14 is a graph showing an example of the change over time of the standardized pixel average moisture index Dw in the second water potential control experiment. The vertical axis of this graph represents the standardized pixel average moisture index Dw, as in FIG. 13. The horizontal axis of the graph represents elapsed time in minutes. In the second water potential control experiment, two plant samples sm2 and sm3 of the same species (for example, tomato) different from the first plant sample sm1 were used. The plant sample sm2 (comparative example) is regularly subjected to regular watering twice in the morning and in the evening. On the other hand, the plant sample sm3 (Example corresponding to the present embodiment) is irrigated while applying water stress based on unirrigation. That is, like the water potential control period (12th to 22nd days) shown in FIG. 13, the plant sample sm3 is not irrigated except at the timing of irrigation.

In the second water potential control experiment, as shown in FIG. 14, the leaves were divided into four periods of a water potential drop period TW1, an optimum watering amount search period TW2, a water stress control period TW3, and a water content recovery period TW4. An observation of the standardized pixel mean moisture index Dw in was made. The target range Bw of the standardized pixel average water content index Dw was set to a value range of 0.70 to 0.80, unlike the target range Bw shown in FIG. This is due to the different plant samples used in the second water potential control experiment.

The initial values of water content in leaves of the comparative example and the example are almost the same as 90.5% and 91.2%, respectively. Further, the standardized pixel average moisture index Dw is almost the same in the vicinity of the value 1.30. In addition, the Brix value representing the sugar content of each of the comparative example and the example is the same as the value of 2.3%.

During the water potential control experiment, the plant sample sm2 of the comparative example was continuously irrigated.

On the other hand, no water was applied to the plant sample sm3 of the example during the water potential drop period TW1 (a period of about 0 to 11520 minutes). As a result, after the initial value was set, the standardized pixel average water content index Dw in the leaves of the comparative example was approximately constant at a value of 1.0, while the standardized pixel average water content index in the leaves of the example was set. Dw gradually decreased, and at the end of the water potential drop period TW1, it was below the lower limit value 0.70 of the target range Bw.

In the optimum irrigation amount search period TW2 (a period of about 11520 to 20160 minutes), first, the standardized pixel average water content index Dw in the leaves of the example was below the lower limit value of 0.70 of the target range, so that the arrow in the figure At the time point (timing) indicated by r1, irrigation with the irrigation amount K1 was performed. As a result, the standardized pixel average water content index Dw in the leaves of the example sharply increased, exceeded the upper limit of the target range Bw, and approached the value 1.00. At this point, it is determined that the irrigation volume K1 was too large. After that, the dry period started, and the standardized pixel average water content index Dw in the leaves of the example again fell below the lower limit of the target range to reach the value of 0.60. When the water-free period ends, irrigation with the irrigation amount K2 is performed at the time indicated by the arrow r2. As a result, the standardized pixel average moisture index Dw increased and slightly exceeded the target range Bw. Based on these results displayed on the monitor 50, it is possible to determine that the optimum watering amount is smaller than the watering amounts K1 and K2.

In the water stress control period TW3 (a period of about 20160 to 25920 minutes), when the standardized pixel average moisture index Dw in the leaves of the example starts to fall again and falls below the lower limit value of the target range Bw, irrigation is performed at the time point indicated by the arrow r3. Irrigation was performed with an irrigation amount K3 that was smaller than the amounts K1 and K2. Further, at the time point when the standardized pixel average water content index Dw is below the lower limit value of the target range Bw and is indicated by the arrow r4, irrigation was performed with the irrigation amount K4, as with the irrigation amount K3. As described above, since the irrigation amounts K3 and K4 were intermittently performed, the standardized pixel average water content index Dw was changed to be substantially within the target range Bw while applying water stress to the plant sample sm3. To do. After that, since the leaf of the plant sample sm3 of the example entered a certain period of water depletion, the degree of wilting of the leaf was increased, and the standardized pixel average moisture index Dw was decreased, and the standardized pixel average moisture of the plant sample sm3 was decreased. The index Dw has dropped to a value of 0.4.

During the water content recovery period TW4 (a period of about 25920 to 34560 minutes) after the dry period, the degree of wilting of the leaves of the plant sample sm3 was large, and therefore, the irrigation amount K3 at the time points indicated by arrows r5 and r6, respectively. Irrigation was performed with a irrigation volume K5, K6 higher than K4.

At the end of the water content recovery period TW4, when the water content of the leaves of the plant samples sm2 and sm3 in the comparative example and the example became almost the same value as the initial value (90.7%, 89.0%). As a result of measuring the Brix value representing each sugar content, the Brix value was 2.8% in the comparative example, whereas the Brix value was 3.3% in the example. That is, the Brix value of the comparative example increased by 0.5% before and after the water potential control from the value of 2.3% to 2.8%, but the Brix value of the example increased by 2%. It increased from 3.3% to 3.3%, and increased significantly to 1%.

As described above, in comparison with the plant sample sm2 of the comparative example in which irrigation with a regular irrigation amount was performed without applying water stress, in the plant sample sm3 of the example, the standardized pixel average was applied while applying water stress based on unirrigation. Since the watering was performed at the timing when the water content index Dw reached near the lower limit of the target range, the amount of increase in the sugar content in the leaves increased, and the increase in the sugar content in the leaves due to water stress was observed. As described above, it was found from the water potential control experiment of FIG. 14 that leaf quality is improved by applying water stress.

Here, the measurement of the sugar content in the leaves was performed by the following procedures (T1) to (T5).

(T1) Tomato leaves are dried at a temperature of 105° C. for 2 hours. The water content can be calculated from this change in weight.
(T2) The dried leaves are placed in a mortar, and the leaves are ground and crushed to a powder.
(T3) Pulverized leaf powder is placed in a container containing hot water at 60° C. having a water content four times that of the leaf (before drying) and stirred at room temperature for 2 hours.
(T4) The container containing the leaf powder is left to stand, and the leaf powder is allowed to spontaneously sediment for more than 15 hours.
(T5) The supernatant is extracted and the Brix value is measured with a sugar content meter. However, since this Brix value is a temporary Brix value obtained by using hot water that is four times the water content in the leaves, the true Brix value can be obtained according to Equation (1). Note that the calculation of the true Brix value by the mathematical expression (1) may be performed by the control unit 11 at the time when the Brix value obtained by the sugar content meter is input.

True Brix value (%)=[temporary Brix value×water content×4 times/(1-temporary Brix value)]/[water content+(temporary Brix value×water content×4 times)/(1- Tentative Brix value)] x 100
…… (1)

Based on the above water potential control experiments, the following irrigation amount and irrigation timing are considered. FIG. 15 is a graph illustrating an example of the watering amount and the watering timing. The vertical axis of this graph represents the standardized moisture index (that is, the standardized pixel average moisture index Dw). The horizontal axis represents elapsed time. In the graph, the measurement points are represented by rectangles. The target range Bw is set to a value of 0.8 to 0.9.

The initial value of the standardized pixel average water content index Dw in the leaf is 1.0. When the standardized pixel average water content index Dw gradually decreases from the initial value with the passage of time and reaches near the lower limit value of the target range Bw, the next watering is performed. When the slope (falling speed) at which the standardized pixel average moisture index Dw decreases is "-a", the timing indicated by the arrow ra at which the standardized pixel average moisture index Dw crosses the lower limit of the target range Bw becomes the irrigation point tp. ..

The irrigation amount Kp at the irrigation point tp is obtained by using, for example, the mathematical expression (2).

Water content in leaf next time = Water content in leaf this time + Water absorption from root − Amount of transpiration from leaf (2)

Here, the amount of water absorbed from the root is determined by the amount of watering, the osmotic pressure of the liquid fertilizer (electrical conductivity), the number of roots (surface area), and the like. The amount of transpiration from the leaves can be obtained by the number of leaves, the leaf area, the satiation (that is, the difference between the saturated vapor pressure and the relative humidity), and the like. In general, leaf photosynthesis is active and transpiration is actively performed on a sunny day with a satiation of ³ to 7 g/m ³ (that is, a period in which the relative humidity is around 75% RH). Is said. Therefore, the amount of water in the leaves tends to decrease due to active transpiration on sunny days and mornings, but on the other hand, when the amount of leaves transpiration decreases in the evening (sunset), the amount of water in the leaves rises. To do. In addition, since leaves do not undergo photosynthesis at night, changes in leaf water content are small. On rainy days, the relative humidity is high and transpiration does not occur even if the pores are opened.Therefore, the change in leaf water content is small, and on summer days and other high temperatures, the plant loses more water in the body. Since the stomata are closed so that there is no transpiration, the change in leaf water content is small.

When watering is performed, the standardized pixel average water content index Dw increases, reaches the upper limit of the target range Bw, and then decreases again. At the timing shown by arrow rb, the same irrigation as at the timing shown by arrow ra is performed. After that, at the timing indicated by the arrow rc, the irrigation is performed at the timing when the standardized pixel average moisture index Dw reaches a value of 0.7 below the lower limit of the target range Bw, that is, in the state where the water stress becomes large. Thereby, water stress can be given to a plant.

FIG. 16 is a flowchart illustrating an example of an optimum watering amount search procedure according to the first embodiment. This optimum irrigation amount search operation is a process executed in the optimum irrigation amount search period TW2 shown in FIG. 14, for example, when the irrigation amount search mode button 71 is pressed on the UI screen 60 shown in FIG. It

In the optimum watering amount search operation, first, the control unit 11 sets an initial value, an upper limit value and a lower limit value of the target range Bw by a user (for example, a farmer who is a tomato grower) operation on the UI screen 60 (S41). ). The control unit 11 displays the predicted descent time to the lower limit value of the target range Bw and the scheduled search watering time (S42). In addition, this scheduled search and irrigation time is set to the same time as the predicted descent time or a time close thereto.

The control unit 11 displays the search watering amount input screen 61 shown in FIG. 18 (S43). The control unit 11 determines whether or not the input of the search irrigation amount has been completed (S44), and when the input has not been completed, continues to display the search irrigation amount input screen 61 in step S43.

Further, when the input of the search irrigation amount is completed, the control unit 11 measures the standardized pixel average water content index Dw and adds this measurement point to the graph in the leaf water content monitoring screen Gm1 displayed on the UI screen 60. (S45). The control unit 11 determines whether or not the scheduled search and irrigation time has come (S46). When it is not the scheduled search and watering time, the control unit 11 returns to the process of step S45.

When the scheduled irrigation scheduled time comes, the control unit 11 controls the dripping of the search irrigation amount of water (S47). This search irrigation amount corresponds to the irrigation amounts K1 and K2 in FIG. In addition, the dropping of the search irrigation water may be automatically performed by the fertilizer water supply device WF or may be manually performed by a person. The control unit 11 calculates the moisture index after waiting until the designated time (S48). This designated time is a time designated so that the standardized pixel average moisture index Dw reaches the upper limit value of the target range Bw, and is set based on the predicted descent time and the scheduled search watering time.

The control unit 11 compares the standardized pixel average moisture index Dw with the upper limit value of the target range Bw (S49). When the standardized pixel average water content index Dw exceeds the upper limit of the target range Bw, the control unit 11 returns to step S42 and displays the predicted descent time and the search irrigation scheduled time on the UI screen 60 again. When the standardized pixel average moisture index Dw does not exceed the upper limit of the target range Bw, the control unit 11 returns to step S43 and displays the search watering amount input screen 61.

When the standardized pixel average water content index Dw becomes equal to the upper limit value of the target range Bw, the control unit 11 displays the search watering amount as the optimum water amount so as to shift to the cultivation control process (S50). This display is displayed as a pop-up message, for example. After that, the control unit 11 ends this operation.

FIG. 17 is a diagram showing an example of a user interface (UI) screen 60 relating to water potential control. The UI screen 60 includes a leaf moisture monitoring screen Gm1. On the leaf water content monitoring screen Gm1 arranged on the upper part of the UI screen 60, a graph showing a time-series change of the standardized pixel average water index Dw is displayed. This graph is similar to the graph of FIG. 13 described above.

A setting area 63 is displayed on the lower left side of the UI screen 60. In the setting area 63, an initial setting button 64 and a shift threshold setting button 66 are arranged. Further, an input box 67 for setting an upper limit value of the target range Bw and an input box 68 for inputting a lower limit value of the target range Bw are arranged. A touch panel, a numeric keypad, a mobile terminal, or the like can be used for inputting numerical values into the input boxes 67 and 68.

Further, on the lower right side of the UI screen 60, a watering amount search mode button 71 and a water stress control (cultivation control) mode button 73 are arranged. When the irrigation amount search mode button 71 is pressed, the optimum irrigation amount searching operation shown in FIG. 16 described above is started. When the water stress control (cultivation control) mode button 73 is pressed, the cultivation control operation shown in FIG. 19 described later starts. Further, on the UI screen 60, a display box 72 that displays the set value of the search irrigation amount and a display box 74 that displays the set value of the cultivation irrigation amount are arranged.

FIG. 18 is a diagram showing an example of the search irrigation amount input screen 61 that is popup-displayed on the UI screen 60. On the search irrigation amount input screen 61, the search irrigation amount is input and set in units of milliliters (ml). A touch panel, a numeric keypad, a mobile terminal, or the like can be used to input the search watering amount.

FIG. 19: is a flowchart explaining an example of the water stress control (cultivation control) procedure of 1st Embodiment. This cultivation control operation is processing executed in the water stress control period TW3 shown in FIG. 14, and is executed when the water stress control (cultivation control) mode button 73 is pressed on the UI screen 60 shown in FIG. 17, for example. To be done.

In the water stress control operation, the control unit 11 first displays a cultivation (control) irrigation amount input screen (not shown) (S61). The cultivation irrigation amount input screen is pop-up displayed on the UI screen 60, like the search irrigation amount input screen.

The control unit 11 determines whether or not the input of the cultivation irrigation amount is completed on the cultivation irrigation amount input screen (S62). The cultivation irrigation amount indicates an appropriate irrigation amount obtained in the search process of the optimum irrigation amount search period TW2 (that is, the flowchart shown in FIG. 16). When the input of the cultivation irrigation amount has not been completed, the control unit 11 returns to step S61 and continues to display the cultivation irrigation amount input screen.

On the other hand, when the input of the cultivation irrigation amount is completed, the control unit 11 drops the cultivation irrigation amount of water (S63). The control unit 11 displays the predicted descent time to the lower limit of the target range Bw and the planned cultivation and irrigation time (S64). The planned cultivation and irrigation time is set to the same time as the predicted descent time or a time near the predicted descent time.

The control unit 11 determines whether or not to change the cultivation irrigation amount (S65). When the cultivation irrigation amount is not changed, the control unit 11 proceeds to the process of step S68. On the other hand, when changing the cultivation irrigation amount, the control unit 11 displays the cultivation irrigation amount input screen again (S66). The control unit 11 determines whether or not the input of the cultivation irrigation amount is completed on the cultivation irrigation amount input screen (S67). When the input of the cultivation irrigation amount has not been completed, the control unit 11 returns to step S66 and continues to display the cultivation irrigation amount input screen.

On the other hand, when the input of the cultivation irrigation amount is completed, the control unit 11 determines whether or not the cultivation irrigation scheduled time has come (S68). When the cultivation irrigation scheduled time has not come, the control unit 11 returns to the process of step S64. When the cultivation irrigation scheduled time comes, the control unit 11 drops the cultivation irrigation amount of water (S69). The control unit 11 determines whether to end the cultivation control (S30). When the cultivation control is not ended, the control unit 11 returns to the process of step S64. On the other hand, when ending the cultivation control, the control unit 11 ends this operation.

Next, a water stress profile for giving water stress to a plant will be described. 20A to 20D are diagrams schematically showing an example of the water stress profile. In the water stress profile pf1 shown in FIG. 20A, the moisture index (that is, the standardized pixel average moisture index Dw. The same applies hereinafter) between the upper limit value and the lower limit value of the target range Bw (range of the moisture content of the target). Irrigation is performed so that That is, at the timing of the lower limit value of the target range Bw, irrigation of such an amount that the upper limit value of the target range Bw is reached is performed. In this case, the water stress is small.

In the water stress profile pf2 shown in FIG. 20(B), irrigation is performed at the lower limit of the target range Bw, the peak of the standardized pixel average moisture index Dw falls in the middle of the target range Bw, and the standardized pixel average moisture index Dw of Try to reduce fluctuations. In this case, the water stress is quite small.

In the water stress profile pf3 shown in FIG. 20(C), after the standardized pixel average water index Dw is lowered to the atrophy point, irrigation is performed with a large amount of irrigation until the standardized pixel average water index Dw exceeds the value 1. After raising it, it is lowered to the atrophy point again, and irrigation is performed in the same manner. In this case, there is no water stress in the region where the standardized pixel average water index Dw exceeds the value 1, and the water stress is large near the wilting point. This water stress profile pf3 is used, for example, when the moisture index changes at the flowering or fruiting time of the plant in the other stage, or when it changes depending on the weather.

In the water stress profile pf4 shown in FIG. 20(D), the standardized pixel average water content index Dw is lowered to the atrophy point, and then the irrigation is performed with an irrigation amount that reaches the upper limit of the target range Bw, and the standardized pixel average water content is determined. When the index Dw reaches the upper limit value of the target range Bw and then reaches the lower limit value of the target range Bw again, the irrigation is performed with such an amount of irrigation that the upper limit value of the target range Bw is reached. Such an operation is alternately repeated. In this case, when the standardized pixel average moisture index Dw is near the wilting point, the water stress is large, but when it is near the lower limit of the target range Bw, the water stress is small. Note that these water stress profiles are merely examples, and other water stress profiles can be applied.

As described above, in the plant detection camera 1 according to the first embodiment, the first projection light source 13 of the plant detection camera 1 has a first wavelength (905 nm) near-infrared light having a characteristic of being hard to be absorbed by water by optical scanning. (Reference light) is irradiated toward the leaf PT3 of the plant PT. The second projection light source 15 of the plant detection camera 1 irradiates the leaf PT3 of the plant PT with near-infrared light (measurement light) of a second wavelength (1550 nm) having a characteristic of being easily absorbed by water by optical scanning. .. The threshold value setting/moisture index detection processing unit 27a, based on the reflected light of 905 nm reflected at all irradiation positions of the leaf PT3 and the reflected light of 1550 nm reflected at all irradiation positions of the leaf PT3, the total reflection intensity ratio ΣLn( I ₉₀₅ /I ₁₅₅₀ ), the sum of water index of one leaf and the pixel average water index are calculated. The control unit 11 displays, on the UI screen 60 of the monitor 50, a graph representing a time-series transition of the amount of water contained in the leaf PT3 of the plant PT from the start to the end of the measurement period. On the leaf PT3 of the plant PT, a white background plate bd (background object) that covers the back surface of the leaf PT3 of the plant PT when viewed from the first projection light source 13 and the second projection light source 15 is arranged.

As described above, according to the plant detection camera 1, the UI screen 60 of the monitor 50 displays the time series graph of the water content of the leaf PT3 of the plant PT to display the graph of the water content of the plant. Changes can be presented quantitatively and in chronological order. Further, according to the time-series transition of the standardized pixel average water content index Dw included in the leaf PT3 displayed on the UI screen 60 of the monitor 50, the plant detection camera 1 informs the user of the timing of irrigation of the leaf PT3 and the irrigation. It is also possible to teach the amount. The user can perform irrigation with an appropriate irrigation amount at an appropriate irrigation timing from the graph displayed on the UI screen 60 of the monitor 50. Therefore, when a plant such as tomato is to be highly functionalized, optimal cultivation control can be performed, yield can be improved, and productivity can be increased.

In addition, according to the plant detection camera 1, the target range Bw of the standardized pixel average moisture index Dw (water content) of the plant, the initial value of the water content, and unirrigation as an example of applying stress (for example, water stress) Since the change in the amount of water falling is displayed, the user can grasp the water content of the plant in time series.

Further, according to the plant detection camera 1, it is possible to search for an optimum watering amount such that the standardized pixel average water index Dw (water amount) of the plant falls within the target range Bw.

Further, according to the plant detection camera 1, both a decrease in water content due to unirrigation and an increase in water content due to irrigation, which is an example of applying stress (for example, water stress), are displayed. It becomes easier to search for the optimum irrigation amount such that the index Dw falls within the target range Bw.

Further, according to the plant detection camera 1, the target range Bw of the water content of the plant and the change in the water content due to irrigation for keeping the water content of the plant within the target range are displayed. It becomes easy to perform irrigation with the amount of irrigation that falls within the target range.

Further, according to the plant detection camera 1, it is possible to compare and compare the amount of water contained in the plant irrigated with normal irrigation with the amount of water contained in the plant irrigated while applying water stress. Therefore, the user can efficiently and accurately determine the adequacy of the watering amount and the watering timing.

(Modification 1 of the first embodiment)
FIG. 21 is a flowchart illustrating an example of an optimum irrigation amount search procedure in the first modification of the first embodiment. The same step numbers as those in FIG. 16 will be assigned the same step numbers, and the description thereof will be omitted. After waiting for the designated time in step S48, the control unit 11 calculates the moisture index, and then calculates the increment of the standardized pixel average moisture index Dw so that the search irrigation amount and the moisture index are kept in the target range Bw (within range). Is displayed (S49A). Based on these displays, the user can estimate the optimum water content. After that, the control unit 11 ends this operation.

(Second embodiment)
The second embodiment shows a case where the position shift of the leaf occurs due to some influence during continuous measurement of the standardized pixel average water content index Dw in the leaf. When the standardized pixel average water content index Dw in the leaves is measured in time series, for example, when the white background plate to which the leaf to be measured is attached is tilted due to strong wind or collision and the position of the leaf is displaced, it is caused by the irradiation of laser light. The standardized pixel average water content index Dw in the leaves, which is measured by the reflection intensity ratio, changes abruptly.

When the position shift of the leaf to be measured occurs, the data recording the standardized pixel average moisture index Dw in the leaf in time series fluctuates at once and loses its continuity. The data of the standardized pixel average water content index Dw measured in 1 was discarded, and the measurement was repeated from the beginning. As a result, the acquisition efficiency of the measurement data was significantly reduced.

In the second embodiment, even if a leaf position shift occurs, the data of the standardized pixel average moisture index Dw in the leaf can be efficiently used by effectively utilizing the data measured in time series up to that point. It is possible to obtain well and suppress the increase in measurement time.

FIG. 22(A) is a diagram showing an image showing the water content of the leaf to be measured, which is imaged by the plant detection camera 1 according to the second embodiment, and is an example of the image of the leaf before the displacement. .. FIG. 22(B) is a diagram showing an image showing the water content of the leaf to be measured, which is imaged by the plant detection camera 1 of the second embodiment, and an example of the image of the leaf after the positional deviation. .. In the figure, an area having a large number of dots and being dark is an area having a large water content. The darkest (highest water content) region sc1 exists inside the leaf. A region sc2 having the next darkest region (having a slightly high water content) exists around the region sc1. A thin region (having a low water content) region sc3 exists outside the leaves. In addition, the area of the region sc1 having a large water content is increased after the positional deviation compared with before the positional deviation.

FIG. 23 is a graph showing an example of a change over time of the standardized pixel average water content index Dw in the water potential control experiment when the position shift occurs. The vertical axis of this graph represents the standardized pixel average moisture index, as in the first embodiment. The standardized pixel average moisture index represents a water potential, and represents a value corresponding to the amount of moisture contained in one pixel in an image of a plant leaf. The horizontal axis of the graph represents elapsed time in minutes.

When there is a leaf position shift (see timing tc in the figure), the standardized pixel average water content index Dw changes at once. The standardized pixel average water content index Dw in the leaves when there is no displacement of the leaves changes as shown in the graph gh1. On the other hand, the standardized pixel average water content index Dw in the leaves when the leaves are misaligned changes as shown in the graph gh2.

In the second embodiment, even if there is a leaf position shift, correction based on the following consideration is performed to effectively use the data of the standardized pixel average moisture index Dw before the leaf position shift, Data of the time-series standardized pixel average moisture index Dw is acquired so as to maintain continuity with the data of the standardized pixel average moisture index Dw after the displacement of the leaves.

In the following consideration, it is assumed that the leaves are tilted as the positional deviation of the leaves. In this case, the fact that the leaves are tilted in the pan direction or the tilt direction and the angle is changed corresponds to the thickness of the leaves being changed when viewed from the camera.

The water content in the leaf, which is the water content of the leaf (in other words, the water potential), is proportional to the standardized pixel average water index Dw. As described above, the standardized pixel average moisture index Dw constitutes the sum of the reflection intensity ratios Ln(I ₉₀₅ /I ₁₅₅₀ ) and the number of pixels constituting the leaf invisible light image or the leaf visible light imaged image. It is obtained from the number of pixels occupying green (G) among the number of pixels.

It is known that the reflection intensity ratio Ln(I ₉₀₅ /I ₁₅₅₀ ) is substantially proportional to (correlated with) the leaf thickness t as shown in the mathematical formula (3) based on the known Lambert-Beer's law. .. In Expression (3), α is the absorption coefficient of water, t is the thickness of leaves, C is the concentration of water, and β is the scattering loss term.

Ln(I ₉₀₅ /I ₁₅₅₀ )=αtC+β (3)

In summary, the water content (water potential) in the leaf is represented by a linear function of the standardized pixel average water index Dw having the leaf thickness t as a gradient (slope). That is, the inclination of the water content in the leaf changes depending on the leaf thickness t.

As described above, the change in the leaf angle caused by the positional shift corresponds to the change in the inclination due to the leaf thickness t, and therefore corresponds to the change in the leaf angle (the change in inclination due to the leaf thickness t). The data of the standardized pixel average moisture index Dw after the positional deviation can be obtained by multiplying the data of the standardized pixel average moisture index Dw after the positional deviation by the coefficient Q (correction coefficient).

As a result, the data of the standardized pixel average moisture index Dw obtained in time series before and after the positional deviation can maintain continuity. However, the acquisition of the water content immediately before and immediately after the positional deviation is performed within a short time, so that the actual water content does not change between them.

Specifically, an example of correction of the standardized pixel average moisture index Dw before and after the positional deviation will be shown. FIG. 24 is a table showing an example of the standardized pixel average moisture index before and after the positional deviation correction in time series. In this table, in the graph shown in FIG. 23, when a positional deviation occurs at an elapsed time of 16250 minutes (time 17:10), a standardized pixel average moisture index Dw before correction and a standardized pixel average moisture index Dw after correction are displayed. It is shown. Here, the coefficient Q corresponding to the change in the leaf angle is calculated by the control unit 11 as an example of the coefficient calculation unit, and specifically, the value is 0.7303 (=0.6416/0.8785). ..

FIG. 25 is a flowchart illustrating an example of the positional deviation correction procedure according to the second embodiment. The plant detection camera 1 of the second embodiment has almost the same configuration as that of the first embodiment. The same components as those of the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

The control unit 11 acquires the standardized pixel average moisture index Dw1 at the current time and displays it on the UI screen 60 (S91). The control unit 11 acquires and displays the standardized pixel average moisture index Dw2 after the designated elapsed time (for example, 30 minutes) (S92). The designated elapsed time corresponds to the measurement interval.

The controller 11 determines whether or not the difference between the standardized pixel average moisture index Dw1 and the standardized pixel average moisture index Dw2 exceeds the threshold th (S93). The threshold value th is used to determine a value that is assumed to cause a leaf position shift and change the standardized pixel average moisture index Dw.

Here, the threshold th is set in advance. When setting the threshold th, the control unit 11 displays a deviation determination threshold input screen (not shown). The user inputs a threshold value th for determining that a position shift has occurred on the shift determination threshold value input screen. When the input is completed, the control unit 11 displays the input value and accepts the setting of the threshold th.

When the difference between the standardized pixel average water content index Dw1 and the standardized pixel average water content index Dw2 does not exceed the threshold value th, that is, when it is assumed that there is no leaf positional deviation, the control unit 11 proceeds to the process of step S95. On the other hand, when the difference between the standardized pixel average water content index Dw1 and the standardized pixel average water content index Dw2 exceeds the threshold th, the control unit 11 determines that a positional deviation has occurred, and determines the standardized pixel average water content index Dw2 and the subsequent standardized pixel average. The value of the water content index Dw is displayed on the UI screen 60 after correcting the deviation amount (S94).

After that, the control unit 11 determines whether to end the search control for the optimum watering amount, or to end the cultivation control or not (S95). When the search control of the optimum watering amount is not ended and the cultivation control is not ended, the control unit 11 returns to the process of step S91. On the other hand, when ending the search control for the optimum irrigation amount or ending the cultivation control, the control unit 11 ends this operation.

As described above, in the plant detection camera 1 according to the second embodiment, the control unit 11 as an example of the detection unit detects the displacement of the plant. When the displacement of the plant is detected, the control unit 11 calculates a coefficient Q (correction coefficient) to be multiplied by the moisture index after the displacement based on the moisture index before and after the displacement. The control unit 11 corrects the amount of positional deviation by multiplying the coefficient of moisture Q by the moisture index after displacement, and the moisture index before displacement and the moisture index after displacement are corrected so as to maintain continuity. The result is displayed on the UI screen 60 of the monitor 50.

As a result, the continuity of the standardized pixel average water content index Dw in the leaves measured in time series can be maintained even if the leaves are misaligned. Therefore, the standardized pixel average water content index Dw data measured up to that point can be used meaningfully and effectively without wasting it. As a result, it is possible to efficiently obtain time-series data of the standardized pixel average moisture index Dw in the leaf, and suppress an increase in the measurement time of the standardized pixel average moisture index Dw even if a position shift occurs in the middle. can do.

(Modification 1 of the second embodiment)
In the second embodiment described above, the leaf misregistration is determined by whether or not the difference in the standardized pixel average moisture index Dw exceeds the threshold th. However, a case where the leaf misalignment is physically detected will be described.

FIG. 26(A) is a diagram showing a white background plate bd used for detecting the positional deviation in the modification 1 of the second embodiment, and is a front view of the white background plate bd. FIG. 26(B) is a diagram showing a white background plate bd used for detecting a positional deviation in the modified example 1 of the second embodiment, and is a side view of the white background plate bd shown in FIG. 26(A). Is.

A black-painted quadrangular frame body bd11 having a shape like a frame is provided on the peripheral portion of the white background plate bd. In addition, marks mk1 to mk4 of US marks are drawn at the four corners of the front surface of the white background plate bd. A leaf PT3 is attached to the center of the surface of the white background board bd.

When the plant detection camera 1 images the leaf PT3 attached to the white background board bd, the black background frame bd11 is aligned with the frame of the finder so that the white background board bd and the finder of the plant detection camera 1 are parallel to each other. Give a degree. By imaging the white background plate bd in this state, each distance between the marks mk1 to mk4 is compared with a reference distance registered in advance. This reference distance is a distance between the marks mk1 to mk4 imaged when the white background plate bd is set parallel to the plant detection camera 1. When the distances between the marks mk1 to mk4 are shorter than the reference distance, it is determined that the white background plate bd is tilted and causes a positional shift.

For example, it can be understood that the tilt angle is larger as the distance between the marks mk1 and mk4 is shorter than the reference distance. It can be seen that the shorter the distance between the marks mk1 and mk2 compared to the reference distance, the larger the pan angle.

In this way, it is possible to physically detect the positional deviation of the leaves and measure the positional deviation amount. Furthermore, by registering a coefficient Q corresponding to the measured position shift amount, when the process of multiplying the data of the standardized pixel mean moisture index Dw after the position shift is performed, the standardized pixel mean moisture index before and after the correction is performed. It is not necessary to use the Dw data. Therefore, the processing load can be reduced.

(Modification 2 of the second embodiment)
FIG. 27 is a diagram illustrating an example of a mechanical arrangement of the white background board bdd and the plant detection camera 1 in the second modification of the second embodiment. The white background board bdd is attached on the bar 102 that is erected on the base 101, and is installed as a standing tag. The plant detection camera 1 is fixed to a tripod 151. The white background plate bdd is fixed by being mechanically connected to the plant detection camera 1 by a connecting member mp such as a wire or a rod. If the white background plate bdd is misaligned, the change is directly transmitted to the plant detection camera 1. For example, when a large positional deviation occurs, a large change occurs in the image captured by the plant detection camera 1.

The plant detection camera 1 is positioned on the white background board bd when the correlation degree of the images captured in time series is equal to or less than the threshold value, that is, when the similarity between the previous frame image and the current frame image is significantly reduced. You may judge that a gap has occurred. Thereby, the positional deviation of the white background plate bd can be detected relatively easily.

Further, the detection of the positional deviation is not limited to the above method. For example, the plant detection camera 1 may be equipped with an acceleration sensor that senses a shock. When the white background plate bdd is displaced, the change in the white background plate bdd is transmitted to the plant detection camera 1 via the connecting member mp. When the impact is sensed by the acceleration sensor mounted on the plant detection camera 1, it may be detected that the white background plate bdd is displaced.

(Third Embodiment)
In the first embodiment, for example, as shown in FIG. 15, when the observation target leaf PT3 is watered, the standardized pixel average water index increases, but in the process of decreasing thereafter due to unirrigation, watering is performed. The timing was when the standardized pixel average moisture index decreased near the lower limit of the target range Bw.

Further, the leaf water content at the time of the next calculation in the plant detection camera 1 is obtained by adding the water absorption amount from the root to the leaf water content at the present time and further subtracting the leaf transpiration amount (Formula (2)). reference). Normally, irrigation causes the roots to absorb water, and leaf water content increases at the next calculation. However, during the time period between the irrigation timing and the next irrigation timing, since the water is not irrigated, the transpiration amount of the leaves during that time varies depending on the environmental conditions (for example, temperature and humidity) around the leaves. However, the plant detection camera 1 of the first embodiment does not consider controlling the transpiration amount in consideration of the environmental conditions around the leaves.

Therefore, in the following third embodiment, the user including the irrigation timing and the like for obtaining a high sugar content and a high yield in consideration of environmental conditions (for example, temperature and humidity) around the leaves that determine the transpiration amount of the leaves. An example of the plant detection camera 1 for instructing to maintain or change the environmental condition around the leaf PT3 in the vinyl house VGH in order to apply the water stress in accordance with the water stress profile according to the preference will be described. Since the configuration of the plant detection camera 1 of the third embodiment is similar to that of the plant detection camera 1 of the first embodiment, description of the same description is omitted and different contents will be described.

FIG. 31 is an explanatory diagram showing an example of the relationship among temperature, relative humidity, and saturation. FIG. 32 is an explanatory diagram showing an example of the transition of leaf transpiration due to changes in temperature and relative humidity. FIGS. 33(A) to 33(D) are diagrams schematically showing examples of water stress profiles based on leaf transpiration due to changes in temperature and relative humidity. 33(A) to (D), the transition of the standardized pixel average moisture index or the standardized moisture index sum in time series is simply shown.

When the environmental conditions around the leaf PT3 (for example, temperature and humidity) change, the satiety difference of the leaf PT3 changes as shown in FIG. As a result, the transpiration amount of the leaf PT3 changes. More specifically, when the temperature around the leaf PT3 decreases and the humidity around the leaf PT3 increases, the difference in saturation becomes small, and the leaf PT3 opens pores but is difficult to evaporate. Further, when the temperature around the leaf PT3 rises and the humidity around the leaf PT3 rises, the difference in satiation increases and the transpiration becomes excessive, so that the leaf PT3 closes its pores so as not to lose water. Generally, photosynthesis of the leaf PT3 is active and a suitable satiation is said to be ^{3 to} 7 (g/m ³ ), which is within a range surrounded by a dotted line CU1 and a dotted line CU2 shown in FIG. The temperature and humidity at which the difference in saturation is obtained are preferable as the environmental conditions around the leaf PT3.

(1) A1 state before change in FIG. 32→A1-state after change in FIG. 32 When this state transition occurs, the temperature rises and the humidity falls, but the satiation falls within the range suitable for photosynthesis of the leaf PT3. Therefore, the transpiration of leaf PT3 becomes active. In other words, since the transpiration amount of the leaf shown in Formula (2) increases, the slope -a shown in FIG. 15 increases, and the irrigation point becomes faster. Therefore, the plant detection camera 1 increases the inclination -a shown in FIG. 15 by instructing the control device 200 so that the temperature and humidity are such that the saturated difference in the changed state A1- is obtained, and the irrigation point is increased. Can be accelerated.

(2) A2 state before change in FIG. 32→A2-state after change in FIG. 32 When this state transition occurs, the temperature decreases and the humidity rises, but the satiation falls within the range suitable for photosynthesis of the leaf PT3. Therefore, the transpiration of leaf PT3 becomes active. In other words, since the transpiration amount of the leaf shown in Formula (2) increases, the slope -a shown in FIG. 15 increases, and the irrigation point becomes faster. Therefore, the plant detection camera 1 increases the inclination -a shown in FIG. 15 by instructing the control device 200 so that the temperature and humidity are such that the saturated difference in the changed state A2- is obtained, and the watering point is increased. Can be accelerated.

(3) A3 state before change in FIG. 32→A3-state after change in FIG. 32 When this state transition occurs, the temperature decreases and the humidity rises, but the satiation does not fall within the range suitable for photosynthesis of the leaf PT3. Transpiration of leaf PT3 is reduced. In other words, since the transpiration amount of the leaf shown in Formula (2) decreases, the slope -a shown in FIG. 15 decreases and the irrigation point becomes slower. Therefore, the plant detection camera 1 decreases the inclination -a shown in FIG. 15 by instructing the control device 200 so that the temperature and humidity are such that the saturated difference in the changed A3-state is obtained, and the irrigation point. Can be delayed.

(4) A4 state before change in FIG. 32→A4-state after change in FIG. 32 When this state transition occurs, the temperature rises and the humidity falls, but the satiety is not included in the range suitable for photosynthesis of the leaf PT3. Transpiration of leaf PT3 is reduced. In other words, since the transpiration amount of the leaf shown in Formula (2) decreases, the slope -a shown in FIG. 15 decreases and the irrigation point becomes slower. Therefore, the plant detection camera 1 decreases the inclination -a shown in FIG. 15 by instructing the control device 200 so that the temperature and humidity are such that the saturated difference in the A4-state after the change is obtained, and the watering point. Can be delayed.

Therefore, as shown in FIG. 33(A), the plant detection camera 1 can obtain a water stress profile in which the slopes of the standardized pixel average moisture index or the sum of the standardized moisture indices are both constant values at the time of decrease and at the time of increase. In addition, the control device 200 can be instructed to control the ambient temperature and humidity.

In addition, as shown in FIG. 33(B), the plant detection camera 1 makes the slope of the standardized pixel average moisture index or the sum of the standardized moisture indices gentle when decreasing and increases the slope when increasing in FIG. 33(A). The control device 200 can be instructed to control the ambient temperature and humidity so as to obtain a water stress profile that is the same as the time gradient. In this case, the slope of the standardized pixel average moisture index or the sum of the standardized moisture indices decreases when the irrigation timing decreases, so that the irrigation timing has a longer interval than the irrigation timing in FIG.

Further, as shown in FIG. 33(C), the plant detection camera 1 controls the ambient temperature and humidity so that a water stress profile that does not increase or decrease the standardized pixel average moisture index or the total sum of standardized moisture indices in a certain period is obtained. Can be instructed to the control device 200. In this case, since the transpiration of the leaf PT3 is reduced in a certain period, the irrigation timing is longer than the irrigation timing in FIG. 33(A).

In addition, as shown in FIG. 33(D), the plant detection camera 1 shows the slope of the standardized pixel average moisture index or the standardized moisture index sum at the time of decrease and at the time of increase shown in FIG. 33(A). The control device 200 can be instructed to control the ambient temperature and humidity so as to obtain a water stress profile having a value larger than the slope of. In this case, the transpiration of the leaves PT3 becomes vigorous, decreases, and fluctuates drastically, and therefore the irrigation timing is shorter than the irrigation timing in FIG. 33(A).

FIG. 34 is a diagram illustrating another example of a user interface (UI) screen regarding water potential control. FIG. 35 is a diagram showing an example of the constant value setting input screen of the environment control mode 300 designated on the UI screen 60 shown in FIG. 34. FIG. 36 is a diagram showing an example of a satiety setting program input screen in the environment control mode designated on the UI screen 60 shown in FIG. 34.

The difference between the UI screen 60 shown in FIG. 34 and the UI screen 60 shown in FIG. 17 will be described, and the same components will be denoted by the same reference symbols and description thereof will be omitted. On the UI screen 60 of FIG. 34, a button of the environmental control mode 300 for controlling the environmental conditions (for example, temperature and humidity) around the leaf PT3 to be observed is provided. When the button of the environment control mode 300 is pressed by the user's operation, the control unit 11 of the plant detection camera 1 monitors the constant value setting input screen Gm2 shown in FIG. 35 or the satiety setting program input screen shown in FIG. Display at 50.

On the constant value setting input screen Gm2 shown in FIG. 35, temperature (° C.), humidity (RH%), wind speed (cm/s), and satiation (g/g) so that a constant satiation (g/m ³ ) can be obtained. m ³ ) input areas are provided respectively, and further an automatic satiation conversion button for automatically calculating the satiation is provided. In FIG. 35, for example, 60 cm/s is input so that the wind speed is constant. The value of the wind speed may be 20 to 180 cm/s, for example, depending on the performance of the air conditioner 227.

When the automatic saturation difference conversion button is pressed after the temperature and humidity are input, the control unit 11 calculates the saturation difference and displays the value of the calculation result in the input area of the saturation difference. When this calculated value or the user's desired satiety value is input and designated and the start button is pressed, the control unit 11 instructs the control device 200 to designate the satiety value around the observation target leaf PT3. An environmental control instruction for obtaining a value is transmitted. This environmental control instruction may include only the desired saturation value, or may include not only the saturation value but also the temperature and humidity for obtaining the saturation value. When the control device 200 receives the environmental control instruction from the plant detection camera 1, the control device 200 obtains the satiety difference value, or the temperature, humidity, and satiety difference value included in the environmental control instruction, so that each device in the greenhouse VGH can obtain the satiety difference value. Initiate control or maintain control.

On the satiety difference setting program input screen Gm3 shown in FIG. 36, a drawing area of the time change of the set temperature (° C.) and the set humidity (RH%) is provided so that the user can specify an arbitrary satiety difference. .. Further, as shown in FIG. 36, with respect to the set temperature (° C.), input regions for the temperature lowering rate (° C./h), the holding time (h), and the temperature rising rate (° C./h) may be provided respectively. Similarly, with respect to the set humidity (RH%), input regions for the humidification rate (%/h), the holding time (h), and the drying rate (%/h) may be provided.

When the automatic satiation conversion button is pressed after the set temperature and the set humidity have been drawn and designated, the control unit 11 calculates the set difference and changes the set temperature and the set humidity with the change in the set difference in time. Display on screen. After this, when the start button is pressed by the user's operation, the control unit 11 causes the control device 200 to perform the environmental control for obtaining the change over time of the satiety value drawn and drawn around the observation target leaf PT3. Send instructions. This environmental control instruction may be only the change over time of the desired satiety value, or not only the information about the change over time of the satiety value but the set temperature and set humidity for obtaining the change over time of the satiety value. It is also possible to include the information of each time change of. When the control device 200 receives the environmental control instruction from the plant detection camera 1, the control device 200 obtains information about the time change of the satiety value included in the environmental control instruction, or the time change of the set temperature, the set humidity, and the satiety value. As described above, the control of each device in the greenhouse VGH is started or maintained.

Note that, in FIG. 36, an example has been described in which both the set temperature and the set humidity are changed by the user's operation, but the environmental conditions for changing at least one of the set temperature and the set humidity may be controlled.

Next, an operation procedure relating to control of environmental conditions around the plant PT of the plant detection camera 1 according to the third embodiment will be described with reference to FIG. 37. FIG. 37 is a flowchart illustrating an example of a control operation procedure of the environmental condition of a plant according to the third embodiment.

In FIG. 37, every time the threshold setting/moisture index detection processing unit 27a calculates the moisture index (standardized pixel average moisture index or standardized moisture index sum) of the leaf PT3 (S111), the control unit 11 calculates it in step S111. The most recently calculated K (K: natural number of 2 or more) water index including the water index of the leaf PT3 is obtained (S112). That is, the control unit 11 can recognize the change in the increase or decrease in the water index of the leaf PT3 in step S112. If only one moisture index has been acquired, the control unit 11 does not perform the processing of step S112 and subsequent steps until acquiring two or more moisture indexes.

The control unit 11 determines whether or not the transition of the increase/decrease in the K moisture index matches the transition shown in the predetermined water stress profile (S113). The predetermined water stress profile is, for example, one of the water stress profiles shown in FIGS. 33(A) to (D), and the farmer who is the user increases the sugar content in growing the plant PT (for example, tomato). This is the water stress profile that we consider necessary for this.

When the control unit 11 determines that the transition of the increase or decrease of the K water index matches the transition shown in the predetermined water stress profile (S113, YES), the leaf PT3 evaporates so as to follow the predetermined water stress profile. As a result, an environmental control instruction including maintenance of surrounding environmental conditions (for example, temperature and humidity) is generated, and the maintenance instruction is transmitted to the control device 200 (S114).

On the other hand, when the control unit 11 determines that the change in the increase or decrease of the K water index does not match the change indicated by the predetermined water stress profile (S113, NO), the leaf PT3 follows the predetermined water stress profile. As described above, it is determined that the evaporation has not occurred, and an environmental control instruction including a change in ambient environmental conditions (for example, temperature and humidity) is generated, and the maintenance instruction is transmitted to the control device 200 (S115).

When the control of the water potential (that is, the measurement of the moisture index) is not completed (S116, NO), the process of the plant detection camera 1 returns to step S111, and the step of the control of the water potential (that is, the measurement of the moisture index) is completed until the step is completed. The processing of S111 to S115 is repeated. On the other hand, if the control of the water potential (that is, the measurement of the water content index) is completed (S116, YES), the process shown in FIG. 37 is completed.

As described above, the plant detection camera 1 of the third embodiment is calculated by being connected to the control device 200 for controlling the environmental conditions (for example, temperature and humidity) around the leaf PT3 of the plant PT to be observed. The controller 200 is instructed to change or instruct the environmental condition at the time of calculating the latest moisture index based on the change in increase or decrease of the moisture index (for example, the standardized pixel average moisture index) as the amount of moisture contained in the leaf PT3.

As a result, the plant detection camera 1 obtains the moisture index according to the water stress profile according to the user's preference, also in consideration of the environmental conditions around the leaves (for example, temperature and humidity) that determine the transpiration amount of the leaves. If not, the control device 200 can be instructed to change the environmental condition around the leaf PT3 in the vinyl house VGH. In other words, the plant detection camera 1 gives an instruction to maintain or change the environmental conditions around the leaf PT3 in the vinyl house VGH, thereby responding to the user's preference including the irrigation timing for obtaining a high sugar content, for example. It is possible to support the creation of an environment that gives water stress according to the water stress profile.

Further, the plant detection camera 1 displays, on the monitor 50, the change in the amount of water contained in the leaf PT3 of the plant PT from the start to the end of the control (measurement) of the water potential in a time series manner. As a result, the plant detection camera 1 quantifies the transition of the water content of the plant by displaying a graph showing the time-series transition of the water content of the leaf PT3 of the plant PT on the UI screen 60 of the monitor 50. Can be presented in a timely manner.

Further, the environmental condition is the temperature around the leaf PT3 to be observed, and the plant detection camera 1 transmits to the control device 200 a change instruction to raise or lower the temperature around the leaf PT3. As a result, the control device 200 raises the temperature around the leaf PT3 by controlling each device connected to the control device 200 in the greenhouse VGH according to the change instruction from the plant detection camera 1. It is possible to lower or lower. The plant detection camera 1 can obtain the moisture index according to the water stress profile according to the preference of the user after the temperature control is executed by the control device 200.

The environmental condition is the humidity around the leaf PT3 to be observed, and the plant detection camera 1 transmits to the control device 200 a change instruction to increase or decrease the humidity around the leaf PT3. As a result, the control device 200 raises the humidity around the leaf PT3 by controlling each device connected to the control device 200 in the greenhouse VGH according to the change instruction from the plant detection camera 1. It is possible to lower or lower. The plant detection camera 1 can obtain the moisture index in accordance with the water stress profile according to the user's preference after the humidity up/down control is executed by the control device 200.

The environmental conditions are the temperature and humidity around the leaf PT3 to be observed, and the plant detection camera 1 raises the temperature around the leaf PT3 and lowers the humidity, or lowers the temperature around the leaf PT3. In addition, a change instruction to increase the humidity is transmitted to the control device 200. As a result, the control device 200 raises the temperature around the leaf PT3 by controlling each device connected to the control device 200 in the greenhouse VGH according to the change instruction from the plant detection camera 1. In addition, the humidity can be lowered, or the temperature around the leaf PT3 can be lowered and the humidity can be raised. The plant detection camera 1 can obtain the moisture index according to the water stress profile according to the preference of the user after the temperature and humidity of the control device 200 are controlled up and down.

Further, the environmental condition is the temperature and humidity around the leaf PT3 to be observed, but the plant detection camera 1 transmits a maintenance instruction to the control device 200 to maintain the temperature and humidity around the leaf PT3. .. As a result, the control device 200 controls the devices connected to the control device 200 in the greenhouse VGH in accordance with the maintenance instruction from the plant detection camera 1 to thereby control the temperature and humidity around the leaf PT3. Can be maintained. The plant detection camera 1 can obtain the moisture index according to the water stress profile according to the preference of the user after the temperature and humidity are maintained and controlled by the control device 200.

A white background plate bd that covers the back surface of the leaf PT3 of the plant PT is arranged on the leaf PT3 of the plant PT when viewed from the first projection light source 13 and the second projection light source 15. As a result, the plant detection camera 1 allows the scattered light from surrounding leaves (for example, outside of sunlight or the like) to be detected even in a leaf group in which a large number of leaves are overgrown around the leaf PT3 that is the target site for plant observation. Since the influence of (light scattering) can be eliminated, the water content of the leaf PT3 can be accurately measured.

Although various embodiments have been described above with reference to the drawings, it goes without saying that the present invention is not limited to such examples. It is obvious to those skilled in the art that various changes or modifications can be conceived within the scope described in the claims, and naturally, these also belong to the technical scope of the present invention. Understood.

In addition, in order to apply stress (for example, water stress) to a plant (for example, tomato leaves), the above-described cultivation device of the present embodiment performs non-irrigation treatment such as interrupting irrigation of the plant. explained. However, in the cultivation apparatus of the present embodiment, the method of applying stress (for example, water stress) to plants is not limited to non-irrigation. For example, the cultivating apparatus of the present embodiment, in order to apply stress (eg, water stress) to the plant, not the unirrigated water, the electric conductivity of the liquid fertilizer (that is, liquid fertilizer) supplied to the plant to a predetermined value or more. You can change it to be larger. That is, by changing the cultivation device so that the electric conductivity of the liquid fertilizer becomes greater than or equal to a predetermined value, water stress equivalent to that of unirrigated water is eventually given to the plant. This is because the electric conductivity of the liquid fertilizer is changed to become larger than a predetermined value, so that the root cannot absorb water due to the osmotic pressure (in other words, salt stress is applied), and as a result, the This is because the plant is subject to water stress, like watering. The predetermined value is a known value obtained from the experience of the grower and is the lower limit value of the electrical conductivity of liquid fertilizer when salt stress is applied to the plant.

INDUSTRIAL APPLICABILITY The present invention is useful as a water content observation device, a water content observation method, and a cultivation device that can flexibly control the water content contained in a plant containing fruits such as tomato in consideration of the influence of surrounding environmental conditions. Is.

DESCRIPTION OF SYMBOLS 1 Plant detection camera 11 Control part 11a Timing control part 13 1st projection light source 15 2nd projection light source 17 Projection light source scanning optical parts 21, 31 Imaging optical parts 23, 33 Light receiving part 25 Signal processing part 25a I/V conversion circuit 25b Amplifier circuit 25c Comparator/peak hold processing unit 27 Detection processing unit 27a Threshold setting/moisture index detection processing unit 27b Memory 27c Detection result filter processing unit 29 Display processing unit 35 Imaging signal processing unit 37 Display control unit 50 Monitor 60 UI (user interface) ) Screen 61 Search watering amount input screen 63 Setting area 64 Initial setting button 66 Shift threshold setting button 67, 68 Input box 71 Watering amount search mode button 72, 74 Display box 73 Water stress control (cultivation control) mode button 200 Control device 201 I/F unit 203 Built-in clock 205 Calculation processing unit 207 Storage unit 211 Environment sensor 213, 215 Open/close valve 217 Water pump 219 Side window 221 Ventilation device 223 Ceiling curtain 225 Side curtain 227 Air conditioner 1000 Plant observation system BB Base bd, bdd White Background plate bd1 Opening bd2 Hole bd3, bd4, bd5, bd21 Slit bd11 Frame Bw Target range gh1, gh2 Graph Gm1 Leaf moisture monitoring screen JG Image determination unit PT3, PT3t Leaf LS1 Reference light LS2 Measuring light MT communication terminal NVSS Non-visible light sensor pf1, pf2, pf3, pf4 Water stress profile PJ Projection unit TR Light source scanning timing signal RF Light source emission signal RV0 Ambient light RV1, RV2 Diffuse reflected light VGH Vinyl house VSC Visible light camera WF Fertilizer water supply device

Claims (10)

A water content observation device for observing the water content of a plant,
By optical scanning, a first light source that irradiates a near-infrared laser reference light of a first wavelength having a characteristic that is difficult to be absorbed by water toward a preset irradiation range including the water content calculation target site of the plant,
A second light source that irradiates the near-infrared laser measuring light of the second wavelength having a characteristic of being easily absorbed by moisture toward the irradiation range by the optical scanning;
In a fixed measurement period, the reflected light of the near infrared laser reference light reflected at each irradiation position of the irradiation range and the reflected light of the near infrared laser measurement light reflected at each irradiation position of the irradiation range, Based on, a water content calculation unit that repeatedly calculates the water content in the water content calculation target site of the plant,
The environmental condition is changed based on the transition of the increase or decrease of the water content in the water content calculation target part of the plant that is connected to the environment control device that controls the environmental condition around the plant and is calculated by the water content calculation unit. Or a control unit for instructing the environment control device to maintain,
Water content observation device. The water content observation device according to claim 1, wherein
Further comprising a threshold value holding unit for holding a threshold value of a reflection intensity ratio which is an intensity ratio between the reflected light of the near infrared laser reference light and the reflected light of the near infrared laser measurement light ,
The water content calculation unit calculates the reflection intensity ratio of each of the irradiation positions, and the total reflection intensity ratio of the irradiation positions that is equal to or more than the threshold value among the calculated reflection intensity ratios of the irradiation positions , the plant. Calculate as the water content in the water content calculation target part of
Water content observation device. The water content observation device according to claim 1 or 2, wherein
The control unit, calculated by the water content calculating unit, displays the change in increase or decrease in the water content contained in the plant from the start to the end of the measurement period in time series on the display unit,
Water content observation device. The water content observation device according to any one of claims 1 to 3,
The environmental condition is the temperature around the plant,
The control unit transmits a change instruction to increase or decrease the ambient temperature of the plant to the environmental control device,
Water content observation device. The water content observation device according to any one of claims 1 to 3,
The environmental condition is the humidity around the plant,
The control unit transmits a change instruction to increase or decrease the humidity around the plant to the environment control device,
Water content observation device. The water content observation device according to any one of claims 1 to 3,
The environmental conditions are temperature and humidity around the plant,
The control unit gives a change instruction to increase the ambient temperature of the plant and reduce the ambient humidity of the plant, or an instruction to change the ambient temperature of the plant and increase the ambient humidity of the plant. Transmitting to the environment control device,
Water content observation device. The water content observation device according to any one of claims 1 to 3,
The control unit transmits a maintenance instruction not to change the environmental condition to the environmental control device,
Water content observation device. The water content observing device according to any one of claims 1 to 7,
In the water content calculation target site of the plant, a background object that covers the back surface of the plant is arranged when viewed from the first light source and the second light source,
Water content observation device. A water content observation device according to any one of claims 1 to 8,
Based on a time-series transition of the water content calculated by the water content calculation unit in a part of the measurement period, a cultivation control unit for irrigating the plant with a predetermined amount of water,
Cultivation equipment. A method for observing water content in a water content observing device for observing the water content contained in a plant,
The first light source irradiates the near-infrared laser reference light of the first wavelength having a characteristic of being hardly absorbed by moisture toward a preset irradiation range including the moisture content calculation target site of the plant by optical scanning. ,
The second light source irradiates the near-infrared laser measuring light of the second wavelength having a characteristic of being easily absorbed by moisture toward the irradiation range by the optical scanning,
In a fixed measurement period, the reflected light of the near infrared laser reference light reflected at each irradiation position of the irradiation range and the reflected light of the near infrared laser measurement light reflected at each irradiation position of the irradiation range, Based on, repeatedly calculate the water content in the water content calculation target site of the plant,
Connected to an environmental control device for controlling the environmental conditions around the plant,
Based on the transition of the increase or decrease of the water content in the calculated water content calculation target portion of the plant, instruct the environmental control device to change or maintain the environmental conditions,
Water content observation method.