JP7697704B2 - Fruit surface temperature estimation device, fruit surface temperature estimation method, and program - Google Patents

Description

Article 30, paragraph 2 of the Patent Act applies 1. Disclosure via telecommunications lines Date of website posting: March 14, 2023 Website address: <https://agrmet.jp/conferences/samj2023/#proceedings> 2. Disclosure through the academic conference Date held: March 17, 2023 Name and location of the conference: 2023 National Conference of the Agricultural Meteorological Society of Japan

The present invention relates to a fruit surface temperature estimation device, a fruit surface temperature estimation method, and a program.

When fruit temperatures become too high, high-temperature damage such as sunburn and poor coloring occurs. This has become a problem for many tree species due to the recent rise in temperature caused by global warming. When high-temperature damage occurs, it causes the appearance and quality of the fruit to deteriorate, resulting in a decrease in commercial value. Therefore, in order to prevent high-temperature damage, research has been conducted to estimate fruit temperature from meteorological information such as air temperature, mainly focusing on sunburn in apples (Non-Patent Documents 1, 2).

L. Schrader, J. Zhang, J. Sun ``Environmental Stresses that Cause Sunburn of Apple'' August 2003 Acta Horticulturae 618(618) P379-P405 Okan Ozkaya “A Simple Numerical Model for the prediction of Apple Temperatures under Evaporative Cooling” Research in Agriculture and Agronomy, Vol.2016 (2016), Article ID 884279, P14

Conventional technology requires solving complex equations after preparing many parameters to estimate fruit temperature, which makes the process complicated and tends to increase the introduction cost. As a result, not many fruit growers are able to adopt this technology. The present invention was made in consideration of these circumstances, and one of its objectives is to estimate fruit surface temperature more simply.

The fruit surface temperature estimation device, the fruit surface temperature estimation method, and the program according to the present invention employ the following configuration.
A fruit surface temperature estimation device according to one embodiment of the present invention is a fruit surface temperature estimation device that includes an acquisition unit that acquires information capable of recognizing the size of a fruit and air temperature information, and an estimation unit that estimates the fruit surface temperature based on the size of the fruit and the air temperature information.
A fruit surface temperature estimation method according to one embodiment of the present invention is a fruit surface temperature estimation method in which a fruit surface temperature estimation device acquires information capable of recognizing the size of a fruit and air temperature information, and estimates the fruit surface temperature based on the fruit size and the air temperature information.
A program according to one embodiment of the present invention is a program that causes one or more processors possessed by a fruit surface temperature estimation device to acquire information capable of recognizing the size of a fruit and air temperature information, and estimate the fruit surface temperature based on the fruit size and the air temperature information.
The size of the fruit is expressed, for example, by the diameter or weight of the fruit, but may alternatively be expressed in other ways, such as by the size of a circumscribing rectangle.

The present invention provides a fruit surface temperature estimation device, a fruit surface temperature estimation method, and a program that can more easily estimate fruit surface temperature.

1 is a diagram showing the configuration and usage environment of a fruit surface temperature estimation device 100. 1 is a graph showing the relationship between sunshine hours, direction, and surface temperature of apples. This is a graph showing the relationship between maximum air temperature and maximum fruit surface temperature for apples and mandarins. 1 is a graph showing the relationship between fruit size and fruit surface temperature for peaches, pears, and plums. 4 is a flowchart showing an example of an operation of the first embodiment. 1 is a graph showing the relationship between maximum air temperature and maximum fruit surface temperature taking into account wind speed for apples and mandarins. 1 is a graph showing the relationship between maximum air temperature and maximum fruit surface temperature taking into account wind speed for apples.

Below, a first embodiment of the fruit surface temperature estimation device, fruit surface temperature estimation method, and program of the present invention will be described with reference to the drawings.

First Embodiment
1 is a diagram showing the configuration and usage environment of a fruit surface temperature estimation device 100. The fruit surface temperature estimation device 100 communicates with a terminal device 200 and a weather information server 400, for example, via a network NW. The fruit surface temperature estimation device 100 also communicates with a camera 300, for example, to acquire images.

The terminal device 200 is a terminal connected to the network NW by wire or wirelessly. The terminal device 200 is, for example, a PC, a smartphone, a tablet terminal, or a wearable terminal.

The camera 300 is a camera that can share images with the fruit surface temperature estimation device 100 as necessary. The camera 300 may transmit images via the network NW, or may import images into the fruit surface temperature estimation device 100 using an external storage device. The camera 300 is, for example, a digital camera.

The weather information server 400 is, for example, a server operated by an external organization that distributes weather information. The weather information server 400 stores, for example, mesh data 410, and distributes weather information by referencing the mesh data 410. The mesh data 410 is data in which weather information is recorded for each point divided into sections of, for example, 1 km x 1 km.

The fruit surface temperature estimation device 100 includes, for example, a communication unit 110, an acquisition unit 120, a control unit 130, an estimation unit 150, a notification unit 160, and an image analysis unit 140. These components are realized by, for example, a hardware processor such as a CPU (Central Processing Unit) executing a program (software). Some or all of these components may be realized by hardware (including circuitry) such as an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a GPU (Graphics Processing Unit), or may be realized by cooperation between software and hardware. The program may be stored in advance in a storage device such as an HDD (Hard Disk Drive) or a flash memory (a storage device with a non-transient storage medium), or may be stored in a removable storage medium such as a DVD or a CD-ROM (a non-transient storage medium), and may be installed by mounting the storage medium in a drive device.

The communication unit 110 is, for example, a communication interface for connecting to the network NW. The communication unit 110 is, for example, a network card.

The acquisition unit 120 acquires information from the outside. For example, the acquisition unit 120 acquires meteorological information and the like from an external organization via the communication unit 110, and acquires the size of the fruit. The meteorological information includes, for example, the weather and temperature. The meteorological information may be current information or information at any time in the future. The size of the fruit is expressed, for example, by the fruit diameter or weight. The size of the fruit may be acquired, for example, by analyzing an image captured by the camera 300 described below, or may be acquired as a numerical value measured with a vernier caliper or ruler.

The control unit 130 controls the camera 300 to measure the size of the fruit. The camera 300 is controlled by the control unit 130, and transmits the captured image of the fruit to the image analysis unit 140.

The image analysis unit 140 analyzes the image captured by the camera 300 to derive the size of the fruit. For example, the image analysis unit 140 extracts edge points that are candidates for the outline of the fruit by edge extraction processing, and extracts a series of edge points of a predetermined size as the outline of the fruit. Then, the image analysis unit 140 derives the size of the fruit that can be quantitatively evaluated by finding a circumscribing circle or an approximation circle.

The estimation unit 150 estimates the fruit surface temperature. The estimation unit 150 estimates the fruit surface temperature from the size of the fruit and the air temperature at the location where the fruit tree is located. The estimation method will be described later.

The notification unit 160, for example, notifies the terminal device 200 of the fruit surface temperature for each fruit. The communication unit 150, for example, has a web server function and notifies in the form of a website.

The function of the estimation unit 150 will be described below. The estimation unit 150 estimates the fruit surface temperature by inputting the air temperature into a function (estimation formula) according to the size of the fruit. The air temperature is information obtained from the weather information server 400, and may be the current air temperature or may be estimated based on a future air temperature.

The function is, for example, expressed by equation (1), and is a linear function that increases as the temperature increases. In the equation, αk and βk are both positive coefficients that have different values depending on the type and size of the fruit. Instead of a linear function, other functions (e.g., quadratic functions, exponential functions, etc.) that tend to increase as the temperature increases may be used.

(Fruit surface temperature) = αk × air temperature + βk … (1)

The effectiveness of the above treatment will be explained below. Figure 2 is a graph showing the relationship between sunshine hours, direction, and apple surface temperature. The graph in Figure 2 shows the results of measuring the surface temperature at a position 60° above the equator of the apples at one-minute intervals on a sunny summer day, when six apples in total were prepared - three small fruitlets and three average-sized fruit - and each was placed on a nail attached at a height of 1.2 m so that they were horizontal to the ground. The surface temperature was measured at one-minute intervals for each direction using a thermocouple thermometer. The fruit surface temperature was highest between 2 and 3 p.m. for apples facing southwest and west. Furthermore, the fruit surface temperature was higher for average-sized fruit than for small fruitlets.

FIG. 3 is a graph showing the relationship between the maximum air temperature and the maximum fruit surface temperature for apples and mandarins. In FIG. 3, the maximum air temperature and maximum fruit surface temperature on multiple sunny summer days as well as the values of fruit size are shown in a scatter plot. The graph on the right is a graph for apples, with the circle symbol indicating an apple with a fruit diameter of 60 mm or more, and the triangle symbol indicating an apple with a fruit diameter of less than 60 mm. The graph on the left is a graph for mandarins, with the circle symbol indicating a mandarin with a fruit diameter of 30 mm or more, and the triangle symbol indicating a mandarin with a fruit diameter of less than 30 mm. A sunny day is defined as a day when the total value of the total solar radiation is 10 MJ/m ² or more. For both apples and mandarins, the larger the fruit, the higher the maximum fruit surface temperature tends to be.

Figure 4 is a graph showing the relationship between fruit size and fruit surface temperature for peaches, pears, and plums. In Figure 4, the maximum air temperature and fruit surface temperature were measured on sunny days over an eight-day period for three types of fruit - peaches, pears, and plums, all of which are young - and plotted on a graph. Large fruit A is a large young fruit, and small fruit B is a small young fruit. It can be seen that the fruit surface temperature for all fruits - peaches, pears, and plums - rises in proportion to the maximum air temperature, and that the large fruits have a higher fruit surface temperature than the small fruits.

In other words, regardless of the type of fruit, the larger the fruit, the higher the fruit surface temperature. Also, fruit on trees facing southwest and west between 2 and 3 p.m. is likely to have high fruit surface temperatures. The fact that the fruit surface temperature is likely to be high means that the skin is more likely to get sunburned. The maximum fruit surface temperature on that day can be estimated from the maximum air temperature and the size of the fruit on that day. The estimation unit 150 estimates the fruit surface temperature using an estimation formula that applies the maximum air temperature and the size of the fruit.

The estimation unit 150 may estimate the fruit surface temperature using a function (estimation formula) based on the current air temperature and the size of the fruit obtained from the weather information server 400, for example. The estimation unit 150 may also estimate the future fruit surface temperature using a forecast of the future maximum temperature obtained from the weather information server 400. The air temperature obtained from the weather information server 400 is information on the air temperature of the section in which the fruit trees of the mesh data 410 are located.

[flowchart]
5 is a flow chart showing an example of the operation of the first embodiment. First, the control unit 130 photographs a fruit using the camera 300 (step S100).

Next, the image analysis unit 140 analyzes the size of the fruit using the image of the fruit captured by the camera 300 (step S110).

Next, the acquisition unit 120 acquires the mesh data 410 from the weather information server 400 (step S120). The weather information included in the mesh data 410 is the weather and temperature.

Next, the estimation unit 150 determines whether the weather at the location where the target fruit is located is sunny or not (step S130). If the weather is sunny, the process proceeds to the next step. If the weather is not sunny, the operation in this flowchart ends.

Next, the estimation unit 150 estimates the fruit surface temperature by applying the meteorological information contained in the mesh data 410 acquired in the processing of step S120 to the estimation formula (step S140).

Next, the notification unit 160 notifies the terminal device 200 of the estimated fruit surface temperature (step S150). The notification method may be, for example, a method of displaying the screen in the form of a website, or a method using e-mail, etc.

According to the first embodiment described above, it is possible to estimate the fruit surface temperature more simply. As a result, farmers who obtain the estimation results can take measures to prevent sunburn on the fruit skin.

Second Embodiment
The second embodiment will be described below. The configuration of the second embodiment is the same as that of the first embodiment. The mesh data 410 of the weather information server 400 includes wind speed in addition to the weather and temperature. The estimation unit 150 may estimate the fruit surface temperature by applying wind speed in addition to temperature to the estimation formula.

The function is, for example, a linear function expressed by equation (2) that increases as the temperature increases. In the equation, γk and ηk are both positive coefficients that have different values depending on the type and size of the fruit and the wind speed. Instead of a linear function, other functions (e.g., quadratic functions, exponential functions, etc.) that tend to increase as the temperature increases may be used.

(Fruit surface temperature) = γk × air temperature + ηk … (2)

The effectiveness of the above processing will be explained below. Figure 6 is a graph showing the relationship between the maximum air temperature and the maximum fruit surface temperature for apples and mandarins, taking into account the wind speed. Figure 7 shows the maximum air temperature and maximum fruit surface temperature on multiple sunny summer days with weak winds, as well as the values of fruit size, in a scatter plot. The graph on the right is a graph for apples, with the circle symbol indicating an apple with a fruit diameter of 60 mm or more, and the triangle symbol indicating an apple with a fruit diameter of less than 60 mm. The graph on the left is a graph for mandarins, with the circle symbol indicating a mandarin with a fruit diameter of 30 mm or more, and the triangle symbol indicating a mandarin with a fruit diameter of less than 30 mm. A weak wind day is defined as a day when the average wind speed during the day (11:00-16:00) is 3 m/s or less. For both apples and mandarins, the larger the fruit, the higher the maximum fruit surface temperature tends to be, and adding wind speed information allows for a more accurate estimation of the maximum fruit surface temperature.

Fig. 7 is a graph showing the relationship between maximum air temperature and maximum fruit surface temperature for apples, taking into account wind speed. Fig. 7 is a graph showing, in the form of a scatter plot, the values of fruit size on days when the daily total value of global solar radiation is 10 [MJ/ ^m2 ] or more and the average daytime wind speed is 3 [m/s] or less (weak wind days). Circle symbols represent apples weighing 100 [g] or more, and triangular symbols represent apples weighing less than 100 [g]. It can be seen that apples weighing 100 [g] or more tend to have higher maximum fruit surface temperatures. It can also be seen that the higher the fruit weight, the higher the maximum fruit surface temperature, regardless of the specific fruit weight.

According to the second embodiment described above, by estimating the fruit surface temperature more accurately, it becomes easier to take measures to prevent sunburn of the fruit skin.

The above describes the form for carrying out the present invention using an embodiment, but the present invention is not limited to such an embodiment, and various modifications and substitutions can be made without departing from the spirit of the present invention.

REFERENCE SIGNS LIST 100 Fruit surface temperature estimation device 110 Communication unit 120 Acquisition unit 130 Control unit 140 Estimation unit 150 Notification unit 160 Image analysis unit 200 Terminal device 300 Camera 400 Weather information server 410 Mesh data NW Network

Claims (9)

An acquisition unit that acquires information that allows the size of a fruit to be recognized and temperature information;
an estimation unit that estimates a fruit surface temperature based on the size of the fruit and the air temperature information;
A fruit surface temperature estimation device comprising: the estimation unit estimates the fruit surface temperature by inputting the temperature indicated by the temperature information into a function that is a function according to a size of a fruit and that increases as the temperature increases;
The fruit surface temperature estimating device according to claim 1. The estimation unit further estimates the fruit surface temperature based on a wind speed.
The fruit surface temperature estimating device according to claim 1. the estimation unit estimates the fruit surface temperature by inputting the temperature indicated by the temperature information into a function that is a function according to a size of a fruit and a wind speed and that increases as the temperature increases;
The fruit surface temperature estimating device according to claim 3. the information that enables the size of the fruit to be recognized is an image of the fruit;
Further comprising an image analysis unit that derives the size of the fruit by image analysis.
The fruit surface temperature estimating device according to claim 1. The acquisition unit acquires future temperature information,
The estimation unit estimates a future fruit surface temperature based on the future air temperature information.
The fruit surface temperature estimating device according to claim 1. The estimation unit estimates the fruit surface temperature for each point in the mesh data from which air temperature information is acquired.
The fruit surface temperature estimating device according to claim 1. The fruit surface temperature estimation device
Acquire information that allows the size of the fruit to be recognized and temperature information;
estimating a fruit surface temperature based on the size of the fruit and the air temperature information;
Method for estimating fruit surface temperature. One or more processors of the fruit surface temperature estimation device include:
Acquire information that allows the size of the fruit to be recognized and temperature information;
estimating a fruit surface temperature based on the size of the fruit and the air temperature information;
Program for.

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