JP7091963B2 - Object detection sensor and object detection system - Google Patents

Description

Application of Article 30, Paragraph 2 of the Patent Law Published at "Innovation Japan 2018" held on August 30, 2018.

The present invention relates to an object detection sensor and an object detection system that detect the position information (existence and its position) of an object in a non-contact manner.

In various industrial processes, acquiring the existence (presence / absence) and position information of an object is an indispensable function for recognizing and processing an object, and in general, such a function is various. It is realized by using sensors.
In particular, it is often required to detect an object in a non-contact manner, and sensors using light, magnetism, ultrasonic waves, or the like are used. Performance parameters such as the distance that can be detected, the conditions of the object to be detected, the position resolution, and the price of the device are different for each sensor. Therefore, a sensor having a function for realizing the required function is appropriately selected and used.

In any case, these existing sensing technologies require sensor devices with specific functions for detecting objects and advanced electronic circuit technologies, and the higher the required performance, the more complicated the configuration and the cost. Invite high.
For example, the following products are commercially available as proximity sensors capable of detecting an object such as metal over a relatively long distance.

OMRON Long Distance Type Proximity Sensor TL-L
http://www.fa.omron.co.jp/products/family/479/lineup.html
KEYENCE Proximity Sensor
https://www.keyence.co.jp/products/sensor/proximity/
These sensors use the principle of detecting changes in the magnetic field due to eddy currents generated in an object by a high-frequency magnetic field, and can detect an object at a distance of about several mm to several cm. However, the object is limited to a good conductor such as a metal, and it is only possible to detect the proximity of the object, and it is not possible to obtain three-dimensional position information by itself.

As a sensor capable of obtaining three-dimensional position information, a sensor called a TOF camera (TOF: Time Of Flight) has become widespread in recent years.
As the TOF camera, for example, the following products are commercially available.
Panasonic
https://panasonic.co.jp/es/pespl/products/new/tofcamera.html
Basler
https://ttps: //www.baslerweb.com/jp/products/cameras/3d-cameras/time-of-flight-camera/tof640-20gm_850nm/
In all of these sensors, due to the principle of measurement, a strong light source modulated at high frequency and an image sensor or an electronic circuit that makes full use of advanced technology are used, so the configuration is complicated compared to the above proximity sensor. And the cost goes up.

Further, for example, Patent Document 1 discloses a proximity sensor that detects the presence or absence or position of a metal body by using a magnetic field.

Japanese Unexamined Patent Publication No. 2009-59528

However, the above-mentioned conventional object detection sensor has the following problems.
That is, the existing object detection sensor has a limit in terms of performance-to-cost ratio, and the configuration is inevitably complicated in order to have a configuration that can detect an object other than metal over a relatively long distance. Inviting an increase in cost.

An object of the present invention is to provide an object detection sensor and an object detection system capable of acquiring position information of an object by a simple configuration.

The object detection sensor according to the first invention detects and detects a change in the effective dielectric constant around the detection line based on the signal obtained from the change in the propagation delay time of the signal transmitted to the detection line. It is an object detection sensor that detects the presence or absence of an object in the vicinity of the line and the position information of the object including its movement, and is a plurality of detection lines, a transmission unit, a reception unit, a detection unit, and a position information estimation unit. And have. The transmitter sends signals to a plurality of detection lines. The receiving unit receives signals obtained from each of the plurality of detection lines. The detection unit detects the propagation delay time of the signal received from the plurality of detection lines received by the reception unit. The position information estimation unit estimates the position information of the object based on the balance of the signals obtained from the change in the propagation delay time of the signals received from the plurality of detection lines detected by the detection unit.

Here, when an object exists in the vicinity of the detection line, the propagation delay time of the signal transmitted to the plurality of detection lines changes due to the change in the effective dielectric constant around the detection line. The propagation delay time in each detection line is detected. Then, the position information of the object is estimated based on the balance of the signals obtained from the changes in the propagation delay times detected in the plurality of detection lines.

Here, the detection line is an electric wire-like member having an input unit for inputting an electric signal and an output unit for outputting a signal, and has, for example, a serpentine (pulse) shape or a linear shape. is doing.
Further, the position information of the object estimated by the position information estimation unit includes not only the angle of the object seen from the detection line and the distance to the object, but also the presence or absence of the object.

Here, in general, the speed at which an electric signal propagates through an electric wire depends on the permittivity of the space around the electric wire. The permittivity is not always uniform in space, and the strength of the electric field generated by the electric signal also depends on the distance from the electric wire. Is decided. The permittivity of air can be considered to be almost the same as the permittivity of vacuum, but in general, the permittivity of a substance is larger than the permittivity of air, and the ratio to the permittivity of vacuum (relative permittivity) is, for example. , Plastic-based materials are about 2 to 4, and most materials show single-digit values. On the other hand, the dielectric constant of a substance containing polar molecules such as water and alcohol shows a large value of several tens or more.

Further, a material having good conductivity such as metal can be regarded as having an infinite relative permittivity equivalently. Therefore, when an object exists in the vicinity of the electric wire, the effective permittivity of the space around the electric wire becomes larger than that in the case where the object does not exist. This increases the propagation delay time of the electric signal transmitted through the electric wire.
In the object detection sensor of the present invention, an electric wire to which such an electric signal is input / output is used as a detection line, and a time difference between transmitting a signal to a plurality of detection lines and propagating and returning the signal through the line. (Propagation delay time) is measured to detect the signal balance obtained from the change in the propagation delay time.

As a result, whether or not an object is in close proximity to the vicinity of the plurality of detection lines due to the balance of signals indicating changes in the propagation delay time in the plurality of detection lines, or which of the multiple detection lines is used. By detecting whether an object is closest to the detection line, it is possible to estimate the position information such as the position and direction of the object.
Further, if the material, dimensional shape, and the like of the object are known, the distance from the detection line to the object can be estimated even when two detection lines are used, for example.

The object detection sensor according to the second invention is the object detection sensor according to the first invention, and the plurality of detection lines have a first line and a second line.
Here, the object detection sensor is configured by using two detection lines (first line and second line).
As a result, from the first line and the second line to the object based on the balance of the signal indicating the change in the propagation delay time of the signal input to the two detection lines (the first line and the second line), respectively. Position information such as distance and direction can be estimated.

The object detection sensor according to the third invention is the object detection sensor according to the second invention, and the first line and the second line have substantially the same shape and substantially the same dimensions, and have a predetermined distance. Are arranged via.
Here, the first line and the second line having substantially the same shape and dimensions are arranged over a predetermined distance.

As a result, since the first line and the second line have substantially the same shape and substantially the same dimensions, when an object exists at a substantially same distance from the first line and the second line, both lines have substantially the same shape and dimensions. The propagation delay time is about the same.
Therefore, it is possible to easily estimate the position information of the object from the balance of the signals indicating the change in the propagation delay time in the first line and the second line.

The object detection sensor according to the fourth invention is the object detection sensor according to the second or third invention, and the position information estimation unit is the first from the balance of the signals obtained from the first line and the second line. Estimate the angle at which the object exists with respect to the straight line connecting the first line and the second line.
Here, the angle (direction) in which the object exists with respect to the first line and the second line is estimated from the balance of the signals indicating the propagation delay times obtained in the first line and the second line, respectively.

This makes it possible to estimate whether or not an object exists in the vicinity of the first line and the second line, and for example, if the material, size, shape, etc. of the object are known, that object. The distance to can be estimated.

The object detection sensor according to the fifth invention is an object detection sensor according to any one of the second to fourth inventions, and the position information estimation unit is a signal obtained from the first line and the second line. Estimate the distance to the object using the balance of and the sum of the signals.
Here, the direction in which the object exists is estimated based on the balance of the signals obtained from the first line and the second line, and the distance to the object is estimated based on the sum of the signals (voltage value, etc.).
As a result, the direction and distance of objects existing in the vicinity can be estimated by a simple configuration using the first line and the second line.

The object detection sensor according to the sixth invention is the object detection sensor according to the first invention, and the plurality of detection lines include a first line, a second line, a third line, and a fourth line. There is.
Here, the object detection sensor is configured by using four detection lines (first line to fourth line).
As a result, among the signals indicating the change in the propagation delay time of the signal input to each of the four detection lines (first line to the fourth line), for example, the signal on the first line and the second line. Based on the balance and the signal balance between the third line and the fourth line, it is possible to estimate the position information such as the distance and direction from the first line to the fourth line to the object.

The object detection sensor according to the seventh invention is the object detection sensor according to the sixth invention, and the first line, the second line, the third line, and the fourth line are arranged symmetrically at intervals of approximately 90 degrees. Has been done.
Here, the above-mentioned four detection lines (first to fourth lines) are arranged rotationally symmetrically at intervals of approximately 90 degrees with the axis arranged at the center thereof as the center.
As a result, for example, the first line and the second line are arranged at opposite positions, and the third line and the fourth line are arranged at opposite positions, so that the signal balance between the first line and the second line can be obtained. , The presence / absence of an object, position information, and the like can be estimated by using the signal balance between the third line and the fourth line.

The object detection sensor according to the eighth invention is the object detection sensor according to the sixth or seventh invention, and the first line and the second line face each other through a predetermined distance having a first distance. The third line and the fourth line are arranged so as to face each other with a predetermined distance having a first distance.
Here, the distance between the first line and the second line arranged to face each other and the distance between the third line and the fourth line arranged to face each other are the same distance (first distance). Four detection lines (first to fourth lines) are arranged so as to be.

As a result, four detection lines (first line to second line) are rotated around the intersection of the straight line connecting the first line and the second line and the straight line connecting the third line and the fourth line. Can be arranged symmetrically.
Therefore, the presence / absence of an object, position information, and the like can be easily estimated by using the signal balance between the first line and the second line and the signal balance between the third line and the fourth line.

The object detection sensor according to the ninth invention is an object detection sensor according to any one of the sixth to eighth inventions, and the first line, the second line, the third line and the fourth line are abbreviated. It has the same shape and almost the same dimensions.
Here, the four detection lines (first line to fourth line) have substantially the same shape and dimensions.

As a result, the first line and the second line have substantially the same shape and substantially the same dimensions. Therefore, when an object exists at a substantially same distance from the first line and the second line, both lines have substantially the same shape and dimensions. The propagation delay time is about the same. Similarly, since the third line and the fourth line have substantially the same shape and substantially the same dimensions, if an object exists at approximately the same distance from the third line and the fourth line, both lines have substantially the same shape and dimensions. The propagation delay time is about the same.

Therefore, the position information of the object is obtained based on the balance of the signal indicating the change in the propagation delay time in the first line and the second line and the balance of the signal indicating the change in the propagation delay time in the third line and the fourth line. It can be easily estimated.

The object detection sensor according to the tenth invention is an object detection sensor according to any one of the sixth to ninth inventions, and the position information estimation unit is a signal obtained from the first line and the second line. The position of the object is estimated based on the balance and the balance of the signals obtained from the third line and the fourth line.

Here, the direction of the object and the distance to the object are estimated based on the balance of the signals obtained from the first line and the second line and the balance of the signals obtained from the third line and the fourth line.
As a result, the direction and distance of objects existing in the vicinity can be estimated by a simple configuration in which the first line and the second line and the third line and the fourth line are each a set.

The object detection sensor according to the eleventh invention is the object detection sensor according to the sixteenth invention, and the plurality of detection lines are formed in a substantially straight line and are arranged substantially parallel to each other.
Here, a plurality of detection lines formed in a substantially straight line are arranged so as to be substantially parallel to each other.
Thereby, by detecting the change in the signal balance in the plurality of detection lines arranged substantially parallel to each other, the position of the object in the direction orthogonal to the plurality of detection lines can be estimated.

The object detection system according to the twelfth invention has a first system including an object detection sensor according to any one of the eleventh inventions and a second system including an object detection sensor according to any one of the eleventh inventions. It is equipped with a system.
Here, an object detection system including two systems (first system and second system) including a plurality of detection lines formed in a straight line and arranged substantially parallel to each other is configured.

Here, the signal balance indicating the change in the propagation delay time detected in the first system and the second system is collected in the position information estimation unit included in the first system or the second system, and the position information of the object is collected. Presumed.
This makes it possible to estimate the position information of an object using two systems each having a plurality of linear detection lines arranged substantially parallel to each other.

The object detection system according to the thirteenth invention is the object detection system according to the twelfth invention, and in the first system and the second system, a plurality of detection lines formed in a substantially straight line are substantially orthogonal to each other. Arranged to do.
Here, two systems (first system and second system) including a plurality of detection lines formed in a straight line and arranged substantially parallel to each other are provided so that the plurality of linear detection lines are substantially orthogonal to each other. It is placed in.
As a result, the position information of the object can be easily estimated based on the signal balances detected in the first system and the second system arranged so as to be substantially orthogonal to each other.

The object detection system according to the fourteenth invention is the object detection system according to the twelfth or thirteenth invention, and the position information estimation unit balances signals obtained from a plurality of detection lines included in the first system. And the balance of the signals obtained from the plurality of detection lines included in the second system, the position of the object is estimated.

Here, in the position information estimation unit included in the first system or the second system, the position of the object is estimated based on the balance of the signal obtained in the first system and the balance of the signal obtained in the second system. ..
As a result, the position information of the object can be easily estimated based on the signal balances detected in the first system and the second system arranged so as to be substantially orthogonal to each other.

The object detection system according to the fifteenth invention is the object detection system according to the twelfth invention, and further includes a third system including the object detection sensor according to the eleventh invention.
Here, in addition to the two systems (first system and second system) including a plurality of detection lines formed in a straight line and arranged substantially parallel to each other, a third system (third system) is further described. Configure the provided object detection system.
Thereby, the position information of the object can be estimated based on the signal balance detected in each of the three systems.

The object detection system according to the sixteenth invention is the object detection system according to the fifteenth invention, and the first system, the second system, and the third system have a plurality of detection lines formed substantially linearly. They are arranged so as to intersect each other at an angle of approximately 120 degrees.

Here, the above-mentioned three systems (first to third systems) are arranged so that a plurality of detection lines, each of which is substantially linear, intersect each other at an angle of approximately 120 degrees.
As a result, the position information of the object is easily estimated based on the signal balance detected in each of the three systems (first system to third system) arranged so as to intersect at an angle of approximately 120 degrees. be able to.

The object detection system according to the seventeenth invention is the object detection system according to the fifteenth invention, and in the third system, a plurality of detection lines formed in a substantially straight line are arranged so as to be substantially orthogonal to each other. A plurality of detection lines formed in a substantially straight line are arranged so as to intersect each of the first system and the second system at an angle of approximately 45 degrees.

Here, for two systems (first system and second system) including a plurality of detection lines formed in a straight line and arranged substantially parallel to each other, a plurality of detection lines formed in a straight line are provided. The third system (third system) is arranged so as to intersect each other at an angle of approximately 45 degrees.
Thereby, for example, even when a plurality of objects exist in the vicinity of the first system to the third system, the position information of each object can be estimated based on the signal balance detected in each of the three systems. ..

The object detection system according to the eighteenth invention is an object detection system according to any one of the fifteenth to seventeenth inventions, and the position information estimation unit is from a plurality of detection lines included in the first system. An object based on the balance of the obtained signal, the balance of the signals obtained from the plurality of detection lines included in the second system, and the balance of the signals obtained from the plurality of detection lines included in the third system. Estimate the position.

Here, the position information of the object is estimated using the signal balance indicating the change in the propagation delay time obtained in the three systems (first system to the third system).
Thereby, the position information of the object can be easily estimated based on the signal balance detected in each of the three systems.

According to the object detection sensor according to the present invention, the position information of an object can be acquired by a simple configuration.

The control block diagram which shows the structure of the object detection sensor which concerns on one Embodiment of this invention. FIG. 6 is a schematic diagram showing a positional relationship between a detection line included in the object detection sensor of FIG. 1 and an object to be detected. It is explanatory drawing which shows the detection principle of the object position information using the object detection sensor of FIG. The graph which shows the relationship between the distance and the output voltage when the brass round bar of FIG. 3 is in front of the line of each channel. The graph which shows the result of having examined the change of the output voltage of each channel by changing X and Y of FIG. The figure which shows the relationship between the line spacing of two channels of FIG. 3 and the distance from each line to an object. The figure which shows the structure of the object detection system which includes the object detection sensor which concerns on other embodiment of this invention. The figure which shows the structure of the object detection system which includes the object detection sensor which concerns on still another Embodiment of this invention. The figure which shows the structure of the object detection system which includes the object detection sensor which concerns on still another Embodiment of this invention. The figure which shows the structure of the object detection system which includes the object detection sensor which concerns on still another Embodiment of this invention.

(Embodiment 1)
The object detection sensor 1 according to the embodiment of the present invention will be described below with reference to FIGS. 1 to 6.
The object detection sensor 1 according to the present embodiment is a sensor that detects an object 30 (see FIG. 2) existing in the vicinity of a plurality of detection lines 20 (first line 21 and second line 22), and is FIG. 1. As shown in the above, a circuit unit 10 and a detection line 20 are provided.

Specifically, the object detection sensor 1 of the present embodiment is a detection line (first line 21 and second line) when an object exists in the vicinity of a plurality of detection lines (first line 21 and second line 22). By utilizing the fact that the effective dielectric constant around 22) changes and the propagation delay time of the signal transmitted to the plurality of detection lines (first line 21 and second line 22) changes, each detection The propagation delay time on the line (first line 21 and second line 22) is detected. Then, the object detection sensor 1 is an object 30 (see FIG. 2) based on the balance of signals obtained from changes in propagation delay time detected in a plurality of detection lines (first line 21 and second line 22). Estimate the location information of.

As shown in FIG. 1, the circuit unit 10 includes a first pulse generation unit 11a, a first transmission unit 12a, a first reception unit 13a, a first detection unit 14a, a second pulse generation unit 11b, and a second transmission unit 12b. It includes a second receiving unit 13b, a second detecting unit 14b, and a position information estimating unit 15.
The first pulse generation unit 11a generates a pulse signal transmitted to the first line 21.

The first transmission unit 12a transmits a pulse signal generated by the first pulse generation unit 11a to the first line 21 and the first detection unit 14a.
The first receiving unit 13a receives the pulse signal transmitted from the first transmitting unit 12a to the first line 21 and the pulse signal propagating through the first line 21.
The first detection unit 14a compares the pulse signal transmitted from the first transmission unit 12a with the pulse signal received by the first reception unit 13a, and detects the propagation delay time of the pulse signal.

The second pulse generation unit 11b generates a pulse signal transmitted to the second line 22.
The second transmission unit 12b transmits the pulse signal generated by the second pulse generation unit 11b to the second line 22 and the second detection unit 14b.
The second receiving unit 13b receives the pulse signal transmitted from the second transmitting unit 12b to the second line 22 and the pulse signal propagating on the second line 22.

The second detection unit 14b compares the pulse signal transmitted from the second transmission unit 12b with the pulse signal received by the second reception unit 13b, and detects the propagation delay time of the pulse signal.
The position information estimation unit 15 receives the propagation delay time of the pulse signal detected by the first detection unit 14a and the second detection unit 14b, respectively, and changes in the propagation delay time between the first line 21 and the second line 22. Based on the balance, the position information of the object 30 (see FIG. 2) with respect to the first line 21 and the second line 22 is estimated.

Here, the position information of the object 30 estimated by the position information estimation unit 15 is not limited to the position relative to the first line 21 and the second line 22, but is in the vicinity of the first line 21 and the second line 22. Position information indicating whether or not the object 30 exists is also included.
The principle of estimating the position information of the object 30 in the vicinity of the first line 21 and the second line 22 will be described in detail later.

In the detection line 20, when an object 30 (see FIG. 2) is present in the vicinity, the effective dielectric constant of the surroundings changes and the propagation delay time of the signal transmitted to the plurality of lines (first line 21 and second line 22) is delayed. Is installed at a predetermined position in order to detect the propagation delay time on each line (first line 21 and second line 22) by utilizing the change of the first line, as shown in FIG. 21 and a second line 22 are provided.

As shown in FIG. 2, the first line 21 and the second line 22 are configured by laying metal wires having substantially the same shape and a meandering shape (pulse shape) having substantially the same dimensions in a sheet shape. The first line 21 and the second line 22 are configured to sandwich a metal wire between the two insulating films. This makes it possible to prevent noise from being generated due to contact with other conductors.

As the first line 21 and the second line 22, instead of the insulating film, those configured to sandwich the insulatingly coated metal wire with a cloth-like or mesh-like sheet may be used.
The first line 21 has an input unit in which a pulse signal is input from the first transmission unit 12a and an output unit in which the pulse signal is output to the first reception unit 13a.

The second line 22 has an input unit in which a pulse signal is input from the second transmission unit 12b and an output unit in which the pulse signal is output to the second reception unit 13b.
As shown in FIG. 1, the object detection sensor 1 of the present embodiment sends a pulse signal to the first line 21, receives the pulse signal propagated on the first line 21, and detects the propagation delay time. , A pulse signal is sent to the second line 22, the pulse signal propagated on the second line 22 is received, and the propagation delay time is detected. Then, the signals indicating the changes in the propagation delay time on the first line 21 and the second line 22 are compared, and based on the balance, whether or not there is an object 30 in the vicinity of the first line 21 and the second line 22. Or, the position information of the object 30 such as the direction (angle) of the object 30 and the distance to the object 30 is estimated.

Here, the distance between the object 30 to be detected and the respective detection lines (first line 21 and second line 22) changes depending on the position of the object 30. Therefore, the signals indicating the changes in the propagation delay time of the pulse signals obtained from the respective detection lines (first line 21 and second line 22) are compared, and the two detection lines (first line) are compared based on the balance. It is possible to estimate the direction (angle) in which the object 30 exists with respect to the straight line connecting the 1st line 21 and the 2nd line 22).

As a result, the object 30 comes close to the vicinity of the first line 21 and the second line 22 due to the balance of the signals indicating the change in the propagation delay time in the plurality of detection lines (first line 21 and second line 22). It is possible to estimate whether or not the object 30 is present, the direction (angle) of the object 30, or which of the first line 21 and the second line 22 is closer to the object 30.

As a result, by utilizing the fact that the effective permittivity around the first line 21 and the second line 22 changes when the object 30 approaches, the first line 21 and the second line 22 made of a metal wire or the like are simplified. It is possible to estimate the position information such as the position and direction of the object 30 by using various configurations.
Further, in the object detection sensor 1 of the present embodiment, as shown in FIG. 2, detection lines (first line 21 and second line 22) having substantially the same shape and substantially the same dimensions are connected via a certain distance. It is placed in place.

As a result, when the object 30 is equidistant from the first line 21 and the second line 22, the delay time after the pulse signal propagated on the first line 21 and the second line 22 is the first receiving unit 13a and the delay time. It becomes substantially the same in the second receiving unit 13b. Therefore, when the object 30 approaches either the first line 21 or the second line 22, the propagation delay time in the first line 21 and the second line 22 is different, so that the first line can be easily reached. The direction (angle) in which the object 30 exists with respect to the straight line connecting the 21 and the second line 22 can be estimated.

Further, in the object detection sensor 1 of the present embodiment, the distance to the object 30 is estimated based on the sum of the signals obtained from the two detection lines (first line 21 and second line 22).
That is, when the object 30 approaches the first line 21 and the second line 22, the change in the effective permittivity around the first line 21 and the second line 22 becomes large. As a result, the propagation delay time of the pulse signal on the first line 21 and the second line 22 increases due to the change in the effective dielectric constant around the first line 21 and the second line 22.

As a result, when the object 30 is located close to the first line 21 and the second line 22, the effective dielectric constant around the first line 21 and the second line 22 changes significantly, and the pulse signal By using the sum of the signals indicating that the propagation delay time has changed significantly, the distance from the first line 21 and the second line 22 to the object 30 can be estimated.
The distance estimation from the first line 21 and the second line 22 to the object 30 is based on the material, size, etc. of the object 30 recognized in advance, instead of using the sum of the signals indicating the propagation delay time. May be done.

<About the detection principle of object position information>
The principle of estimating the position information of the object 30 by the object detection sensor 1 of the present embodiment will be described below with reference to FIGS. 3 to 6.
Here, as shown in FIG. 3, a parallel conductor (length 160 mm) composed of two conductors having an outer diameter of about 1 mm is short-circuited at one end and folded back to be used as a detection line. Then, two identical lines (first line 21 and second line 22) are arranged in parallel with each other at a distance of 40 mm, one of which is A-ch (first line 21) and the other of which is B-ch (first line). 2 tracks 22).

Then, as the object 30, a cylindrical brass round bar having a diameter of 30 mm and a length of 50 mm is used.
As shown in FIG. 3, the brass round bar (object 30) is brought close to Ach (first line 21) and B-ch (second line 22), and the pulse signal is propagated on each of the lines 21 and 22. The signal obtained from the change in delay time was measured.

As shown in FIG. 3, the position of the brass round bar is the distance X along the straight line direction from the midpoint of the straight line connecting Ach (first line 21) and B-ch (second line 22). And the height Y from the straight line.
The height Y when the brass round bar (object 30) is in front of each channel (first line 21 and second line 22) (on the middle point of the straight line connecting the first line 21 and the second line 22). , The relationship with the output voltage from each channel (first line 21 and second line 22) is represented by the graph shown in FIG.

As shown in this graph, it can be seen that the output voltages from each channel (first line 21 and second line 22) are approximately inversely proportional to the height Y. Therefore, the relationship between the output voltage and the distance r to the brass round bar (object 30) is
s = k / r
Can be approximately expressed as. Here, k is a constant.

Next, FIG. 5 shows the results of examining changes in the output voltage of each channel (first line 21 and second line 22) by changing X and Y.
In the graph shown in FIG. 5, the output voltage from the two channels (first line 21 and second line 22) is the midpoint (X = 0) of the two lines (first line 21 and second line 22). The shape is almost symmetrical with respect to the position. The output voltage of each channel is such that when the brass round bar (object 30) is in front of each channel (first line 21 and second line 22) (A-ch is X = -2 cm, B-ch). Is maximum at X = 2 cm) and becomes smaller as it deviates from the front, and it can be seen that the output voltage becomes smaller as the distance increases.

Therefore, the position information regarding the distance and direction (angle) to the brass round bar (object 30) is estimated based on the magnitude and balance of the output signals of the two channels (first line 21 and second line 22). You can see that you can do it.
Here, as shown in FIG. 6, the distance between the two channels (first line 21 and the second line 22) is d, and the distance from each channel (first line 21 and the second line 22) to the object 30 is r. _{Assuming 1} and r2, these relationships are

によって表される。
これを整理すると、

Represented by.
To organize this,

となる。
それぞれの線路の出力を、Ｓ_１およびＳ_２とすれば、Ｓ_１およびＳ_２は、以下の数式によって表される。

Will be.
Assuming that the outputs of the respective lines are S ₁ and S ₂ , S ₁ and S ₂ are expressed by the following mathematical formulas.

これらを用いて、

With these,

となり、ｋおよびｄは既知であるから、Ｓ_１およびＳ_２からｒを求めることができる。
また、これらは、以下の数式によって表すことができるため、既に求めたｒを元に、各チャンネル（第１線路２１および第２線路２２）に対する物体３０の角度θを取得することができる。

Since k and d are known, r can be obtained from S ₁ and S ₂ .
Further, since these can be expressed by the following mathematical formulas, the angle θ of the object 30 with respect to each channel (first line 21 and second line 22) can be obtained based on the already obtained r.

本実施形態の物体検知センサ１では、以上のように、物体検知を実現するための電子回路（回路部１０、第１・第２線路２１，２２等）は、標準的な半導体デバイスのみの組み合わせによって構成される。
これにより、簡素な構成、かつ極めて低コストで、３次元物体検知の機能を実現することができる。

In the object detection sensor 1 of the present embodiment, as described above, the electronic circuits (circuit unit 10, first and second lines 21, 22 and the like) for realizing the object detection are a combination of only standard semiconductor devices. Consists of.
This makes it possible to realize a three-dimensional object detection function with a simple configuration and extremely low cost.

(Embodiment 2)
The object detection sensor 101 according to another embodiment of the present invention will be described below with reference to FIG. 7.
As shown in FIG. 7, the object detection sensor 101 of the present embodiment has four detection lines (first line 121, second line 122, third line 123, and fourth line) having substantially the same shape and substantially the same dimensions. The lines 124) are arranged rotationally symmetrically at intervals of approximately 90 degrees along the circumferential direction equidistant from the center of the disk. Further, the object detection sensor 101 measures the change in the propagation delay time of the pulse signal from each of the detection lines (first line 121, second line 122, third line 123, and fourth line 124).

Then, from the sum of the signals obtained from the four detection lines (first line 121 to fourth line 124), the position information regarding the presence / absence of the object 30 and the distance from the center of each detection line is estimated.
More specifically, the surface connecting the first line 121 and the second line 122 is determined by the difference in the magnitude of the signal indicating the propagation delay time between the first line 121 and the second line 122 arranged at positions facing each other. The position information of which direction (angle) the object 30 exists in is estimated.

Similarly, the direction in the plane connecting the third line 123 and the fourth line 124 from the difference in the magnitude of the signal indicating the propagation delay time between the third line 123 and the fourth line 124 arranged at positions facing each other. Estimate the position information regarding (angle).
Thereby, the three-dimensional arrangement of the object 30 can be easily estimated by integrating the position information regarding these directions (angles).

Here, it is assumed that the direction from the first line 121 to the second line 122 is the X-axis, the direction from the third line 123 to the fourth line 124 is the Y-axis, and the upward direction perpendicular to the surface including the line is the Z-axis. From the balance between the signal output from the first line 121 and the signal output from the second line 122, the direction (angle) in which the object 30 exists with respect to the surface including the Y axis can be estimated. If this estimated angle is θ, this surface will be

という数式によって示される。
同様に、第３線路１２３から出力される信号と第４線路１２４から出力される信号のバランスに基づいて、Ｘ軸を含む面に対する物体３０が存在する方向（角度）を推定することができ、この角度をΦとすれば、この面は、

It is indicated by the formula.
Similarly, the direction (angle) in which the object 30 exists with respect to the surface including the X-axis can be estimated based on the balance between the signal output from the third line 123 and the signal output from the fourth line 124. If this angle is Φ, this surface will be

と数式によって示される。
この結果、この２つの面の交線は、

Is indicated by a mathematical formula.
As a result, the line of intersection of these two surfaces is

であり、物体３０は、この直線上に存在することを推定することができる。
つまり、それぞれの検出用線路（第１線路１２１～第４線路１２４）から出力される信号のバランスに基づいて、第１線路１２１～第４線路１２４が配置された周方向の中心点から物体３０までの距離を推定することができる。
よって、４つの検出用線路（第１線路１２１～第４線路１２４）を用いて物体検知センサ１０１を構成することで、物体３０の３次元的な位置を容易に推定することができる。

It can be estimated that the object 30 exists on this straight line.
That is, based on the balance of the signals output from the respective detection lines (first line 121 to fourth line 124), the object 30 is located from the center point in the circumferential direction in which the first line 121 to the fourth line 124 are arranged. The distance to can be estimated.
Therefore, by configuring the object detection sensor 101 using four detection lines (first line 121 to fourth line 124), the three-dimensional position of the object 30 can be easily estimated.

(Embodiment 3)
The object detection system 250 including the object detection sensor (first system) 201a to the object detection sensor (third system) 201c according to still another embodiment of the present invention will be described below with reference to FIG. ..

In the system configuration shown in FIG. 8, for convenience of explanation, an object detection sensor (first system) 201a including a plurality of linearly formed lines A1 to A8, and a plurality of linearly formed lines B1 to B8. Of the object detection sensor (second system) 201b including the above, and the object detection sensor (third system) 201c including a plurality of linearly formed lines C1 to C8, only the line portion is shown. However, in an actual configuration, the plurality of lines A1 to A8 and the like each have an input unit and an output unit, and as shown in FIG. 1, a pulse signal is output to each line A1 to A8. It is assumed that it has a configuration in which the propagated pulse signal is received, the propagation delay time is detected, and the position information is estimated. The same applies to the other lines B1 to B8 and C1 to C8.

As shown in FIG. 8, the object detection system 250 of the present embodiment has an object detection sensor 201a having a plurality of linearly formed lines A1 to A8, an object detection sensor 201b having lines B1 to B8, and lines C1 to. It is equipped with an object detection sensor 201c having a C8.
In the object detection sensor 201a, a plurality of linearly formed lines A1 to A8 are arranged at equal intervals and substantially parallel to each other.

In the object detection sensor 201b, a plurality of linearly formed lines B1 to B8 are arranged at equal intervals and substantially parallel to each other.
In the object detection sensor 201c, a plurality of linearly formed lines C1 to C8 are arranged at equal intervals and substantially parallel to each other.
As shown in FIG. 8, the object detection sensors 201a to 201c are arranged so that the lines A1 to A8, the lines B1 to B8, and the lines C1 to C8 intersect each other at an angle of 120 degrees.

As a result, from the distribution of the signal magnitudes obtained as the outputs of the lines A1 to A8, the lines B1 to B8, and the lines C1 to C8 included in the object detection sensors 201a to 201c, the object 30 is which line A1 to. It can be easily estimated whether or not it exists at the position closest to A8, B1 to B8, and C1 to C8.
As a result, by comprehensively using the signal balances obtained from the three systems (object detection sensors 201a to 201c), the coordinates of the foot of the perpendicular line drawn from the object 30 on the surface including each system can be estimated. Further, the distance from each line A1 to A8, B1 to B8, C1 to C8 to the object 30 can be estimated based on the magnitude of the absolute value of each signal.

In the example of FIG. 8, the detection line groups A, B, and C are all composed of eight lines A1 to A8, B1 to B8, and C1 to C8, which are Ai, Bj, and Ck (Ai, Bj, and Ck). Let i, j, k = 1-8).
In the object detection system 250 of the present embodiment, the eight lines A1 to A8, B1 to B8, and C1 to C8 included in the respective object detection sensors 201a to 201c are arranged so as to intersect each other at an angle of about 120 degrees. Has been done.

Therefore, 88 substantially triangular regions surrounded by the respective lines A1 to A8, B1 to B8, and C1 to C8 are formed. In these substantially triangular regions, when the object 30 is present on the region, the output of the lines Ai, Bj, and Ck surrounding this region becomes large.
This makes it possible to easily estimate the position information such as the distance and direction from each line Ai, Bj, Ck to the object 30.

(Embodiment 4)
The object detection system 350 including the object detection sensors 301a and 301b according to still another embodiment of the present invention will be described below with reference to FIGS. 9 and 10.
In the system configuration shown in FIG. 9, for convenience of explanation, an object detection sensor (first system) 301a including a plurality of linearly formed lines A1 to A8 and a plurality of linearly formed lines B1 to B8 are provided. Of the object detection sensor (second system) 301b including the above, only the line portion is shown. However, in an actual configuration, the plurality of lines A1 to A8 and the like each have an input unit and an output unit, and as shown in FIG. 1, a pulse signal is output to each line A1 to A8. It is assumed that it has a configuration in which the propagated pulse signal is received, the propagation delay time is detected, and the position information is estimated. The same applies to the other lines B1 to B8.

As shown in FIG. 9, the object detection system 350 of the present embodiment includes an object detection sensor (first system) 301a and an object detection sensor (second system) 301b.
In the object detection sensor 301a, a plurality of linearly formed lines A1 to A8 are arranged at equal intervals and substantially parallel to each other.
In the object detection sensor 301b, a plurality of linearly formed lines B1 to B8 are arranged at equal intervals and substantially parallel to each other.

As shown in FIG. 9, the object detection sensors 301a and 301b are arranged so that the lines A1 to A8 and the lines B1 to B8 intersect each other at an angle of approximately 90 degrees.
As a result, from the distribution of the signal magnitudes obtained as the outputs of the lines A1 to A8 and the lines B1 to B8 included in the object detection sensors 301a and 301b, which line A1 to A8 and B1 to B8 the object 30 is. It can be easily estimated whether it exists at the position closest to.

Here, for example, when there is only one object 330a, estimating the coordinates of the foot of the perpendicular line drawn from the object 330a on the surface including the line group (tracks A1 to A8 or tracks B1 to B8) is an object detection. It can be realized by two systems of sensors 301a and 301b.
However, for example, as shown in FIG. 9, when a plurality of objects 330a and 330b exist, the object 330a is located at the position closest to the line A2 in the lines A1 to A8 and the line B3 in the lines B1 to B8. Exists in.

Therefore, the position information of the object 330a can be easily estimated by increasing the signal indicating the propagation delay time output from these lines A2 and B3.
Similarly, the object 330b exists at the position closest to the line A5 in the lines A1 to A8 and the line B6 in the lines B1 to B8. Therefore, the position information of the object 330b can be easily estimated by increasing the signal indicating the propagation delay time output from these lines A5 and B6.

However, in the configuration of the present embodiment, as shown in FIG. 9, when a plurality of objects 330a and 330b exist in the vicinity of the lines A1 to A8 and the lines B1 to B8, the propagation delay output from the lines A2 and the line B6. When the signal indicating the time becomes large, it is difficult to distinguish it from the case where an object is on the intersection of the two lines A2 and B6.
Similarly, when the signals output from the lines A5 and B3 become large, it is difficult to distinguish the case where an object is on the intersection of the two lines A5 and B3.

That is, in the configuration of the object detection system 350 of the present embodiment, when a plurality of objects exist within the detection target range, it is estimated as if there is an object even at a position where there is no object. There is a problem that so-called ghosts are erroneously detected.
Therefore, in the object detection system 450 of the present embodiment, as shown in FIG. 10, the two lines A1 to A8 and the lines B1 to B8 are arranged vertically and horizontally so as to intersect each other at approximately 90 degrees. Moreover, the third lines C1 to C8 are arranged so as to intersect these lines A1 to A8 and B1 to B8 at approximately 45 degrees.

Thereby, the above-mentioned problem of false detection of ghost can be solved. Further, the estimation of the position information of the objects 330a and 330b can be carried out by dividing them into a grid pattern as compared with the example of the line arrangement which intersects with each other at an angle of about 120 degrees described with reference to FIG. As a result, there is an advantage that the calculation can be simplified when processing the coordinate data mathematically.

[Other embodiments]
Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the gist of the invention.

(A)
In the above embodiment, signals are transmitted from different transmission units (first and second transmission units 12a and 12b) to the plurality of detection lines (first and second lines 21 and 22), and the signals are sent separately. A configuration in which signals are received by the receiving units (first and second receiving units 13a and 13b) and the propagation delay time is detected by separate detecting units (first and second detecting units 14a and 14b) will be described as an example. did. However, the present invention is not limited to this.
For example, a single transmitter sends signals to multiple detection lines, a single receiver receives signals from multiple detection lines, and a single detector receives each propagation delay. Time may be detected.

That is, as long as the position information estimation unit is common, the transmission unit, the reception unit, and the detection unit may be separately provided for each of the plurality of detection lines, or may be used in common.
In the case of a configuration using a common transmission unit, the signals transmitted from the transmission unit to each detection line may be transmitted at different timings.

(B)
In the above embodiment, an example in which a detection line is formed by a meandering shape (pulse shape) or a linear metal wire has been described. However, the present invention is not limited to this.
For example, the form of the detection line is not limited to a meandering shape or a linear shape, and may be another shape.

(C)
In the above embodiment, an example of detecting position information such as the presence / absence, direction, and distance of an object existing in the vicinity of a detection line by an object detection sensor or an object detection system has been described. However, the present invention is not limited to this.
For example, the object detection sensor may be used as a sensor that detects only the presence or absence of an object, or may be used as a sensor that detects only the direction of an object, depending on the application of the object detection sensor.

(D)
In the above embodiment, in the explanation of the detection principle of the object position information, an example in which a brass round bar is used as the object 30 has been described. However, the present invention is not limited to this.
For example, the object 30 whose position information can be detected by the object detection sensor is not limited to a metal such as a brass round bar, but may be an object made of other materials such as resin, paper, liquid, and rubber. , A moving object such as a person or a passenger car.

(E)
In the above embodiment, an example in which eight linearly formed detection lines are arranged substantially in parallel has been described. However, the present invention is not limited to this.
For example, the number of detection lines formed in a straight line is not limited to eight, and may be increased or decreased depending on the application, the type of the object to be detected, and the like. Further, the arrangement of the detection lines formed in a straight line is not limited to substantially parallel, and may be arranged so as to intersect each other or at positions separated from each other, for example.

(F)
In the above embodiment, as shown in FIG. 1, a first pulse generating unit 11a for generating a pulse signal transmitted to the first line 21 and a pulse signal transmitted to the second line 22 are generated. An example in which the second pulse generating unit 11b and the second pulse generating unit 11b are provided as separate configurations has been described. However, the present invention is not limited to this.
For example, the first pulse generation unit and the second pulse generation unit may be provided as a single pulse generation unit.

Since the object detection sensor of the present invention has the effect of being able to acquire the position information of the object with a simple configuration, it can be widely applied to the proximity detection sensor of the object and the like.

1 Object detection sensor 10 Circuit unit 11a First pulse generation unit 11b Second pulse generation unit 12a First transmission unit (transmission unit)
12b 2nd transmitter (transmitter)
13a First receiver (receiver)
13b 2nd receiver (receiver)
14a First detection unit (detection unit)
14b 2nd detection unit (detection unit)
15 Position information estimation unit 20 Detection line 21 1st line 22 2nd line 30 Object 101 Object detection sensor 121 1st line 122 2nd line 123 3rd line 124 4th line 201a Object detection sensor (1st system)
201b Object detection sensor (second system)
201c Object detection sensor (3rd system)
250 Object detection system 301a Object detection sensor (1st system)
301b Object detection sensor (second system)
330a, 330b Object 350 Object detection system 401a Object detection sensor (1st system)
401b Object detection sensor (second system)
401c Object detection sensor (3rd system)
450 Object detection system A1 to A8 line (detection line)
B1 to B8 line (detection line)
C1 to C8 line (detection line)

Claims (18)

Based on the signal obtained from the change in the propagation delay time of the signal transmitted to the detection line, the change in the effective dielectric constant around the detection line is detected to determine the presence or absence of an object in the vicinity of the detection line. It is an object detection sensor that detects the position information of an object including its movement.
A plurality of the detection lines including metal wires having substantially the same shape and dimensions ,
A transmission unit that sends the signal to the plurality of detection lines, and a transmission unit.
A receiving unit that receives the signal obtained from each of the plurality of detection lines, and a receiving unit.
A detection unit that detects the propagation delay time of the signal from the plurality of detection lines received by the reception unit, and a detection unit.
A position information estimation unit that estimates the position information of the object based on the balance of the signal obtained from the change in the propagation delay time of the signal received from the plurality of detection lines detected by the detection unit.
The object detection sensor equipped with. The plurality of detection lines have a first line and a second line.
The object detection sensor according to claim 1. The first line and the second line are arranged via a predetermined distance.
The object detection sensor according to claim 2. The position information estimation unit estimates the angle at which the object exists with respect to the straight line connecting the first line and the second line from the balance of the signals obtained from the first line and the second line.
The object detection sensor according to claim 2 or 3. The position information estimation unit estimates the distance to the object by using the balance of the signals obtained from the first line and the second line and the sum of the signals.
The object detection sensor according to any one of claims 2 to 4. The plurality of detection lines have a first line, a second line, a third line, and a fourth line.
The object detection sensor according to claim 1. The first line, the second line, the third line, and the fourth line are arranged rotationally symmetrically at intervals of approximately 90 degrees.
The object detection sensor according to claim 6. The first line and the second line are arranged so as to face each other with a predetermined distance having a first distance.
The third line and the fourth line are arranged so as to face each other with a predetermined distance having the first distance.
The object detection sensor according to claim 6 or 7. The first line, the second line, the third line, and the fourth line have substantially the same shape and substantially the same dimensions.
The object detection sensor according to any one of claims 6 to 8. The position information estimation unit determines the position of the object based on the balance of the signals obtained from the first line and the second line and the balance of the signals obtained from the third line and the fourth line. To estimate,
The object detection sensor according to any one of claims 6 to 9. The plurality of detection lines are formed substantially linearly and are arranged substantially parallel to each other.
The object detection sensor according to claim 1. The first system including the object detection sensor according to claim 11 and
The second system including the object detection sensor according to claim 11 and
Object detection system equipped with. In the first system and the second system, the plurality of detection lines formed in a substantially straight line are arranged so as to be substantially orthogonal to each other.
The object detection system according to claim 12. The position information estimation unit is based on the balance of the signals obtained from the plurality of detection lines included in the first system and the balance of the signals obtained from the plurality of detection lines included in the second system. To estimate the position of the object,
The object detection system according to claim 12 or 13. A third system including the object detection sensor according to claim 11 is further provided.
The object detection system according to claim 12. The first system, the second system, and the third system are arranged so that the plurality of detection lines formed in a substantially straight line intersect each other at an angle of approximately 120 degrees.
The object detection system according to claim 15. The third system is formed substantially linearly with respect to the first system and the second system in which the plurality of detection lines formed substantially linearly are arranged so as to be substantially orthogonal to each other. A plurality of detection lines are arranged so as to intersect each other at an angle of approximately 45 degrees.
The object detection system according to claim 15. The position information estimation unit has the balance of the signals obtained from the plurality of detection lines included in the first system, the balance of the signals obtained from the plurality of detection lines included in the second system, and the said. The position of the object is estimated based on the balance of the signals obtained from the plurality of detection lines included in the third system.
The object detection system according to any one of claims 15 to 17.

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