CN110908006B

CN110908006B - Object detection sensor and object detection system

Info

Publication number: CN110908006B
Application number: CN201910728043.4A
Authority: CN
Inventors: 出口干雄
Original assignee: Omron Corp
Current assignee: Omron Corp
Priority date: 2018-09-14
Filing date: 2019-08-08
Publication date: 2023-09-22
Anticipated expiration: 2039-08-08
Also published as: JP7091963B2; CN110908006A; JP2020046190A

Abstract

The invention provides an object detection sensor capable of acquiring position information of an object with a simple structure. The object detection sensor includes: the 1 st line and the 2 nd line, the 1 st transmitting unit, the 1 st receiving unit, the 1 st detecting unit, the 2 nd transmitting unit, the 2 nd receiving unit, the 2 nd detecting unit, and the position information estimating unit. The 1 st and 2 nd transmission units transmit signals to the 1 st and 2 nd lines. The 1 st and 2 nd receiving units receive signals respectively obtained from the 1 st and 2 nd lines. The 1 st and 2 nd detecting units detect propagation delay times of signals from the 1 st and 2 nd lines received in the 1 st and 2 nd receiving units. The position information estimating unit estimates position information of the object based on a balance of signals obtained from a change in propagation delay time of the signals received from the 1 st and 2 nd lines detected in the 1 st and 2 nd detecting units.

Description

Object detection sensor and object detection system

Technical Field

The present invention relates to an object detection sensor and an object detection system that detect positional information (presence and position) of an object in a noncontact manner.

Background

In various industrial processes, the acquisition of presence (presence) and position information of an object is an indispensable function for identifying and processing a target object, and generally, such a function is realized using various sensors.

In particular, there are many cases where it is required to detect an object in a noncontact manner, and sensors using light, magnetism, ultrasonic waves, and the like are used. Performance parameters such as a detectable distance, conditions of a detection target object, position resolution, and the like, or a device price are different from one sensor to another. Accordingly, a sensor having a function for realizing a desired function is appropriately selected and used.

In any case, in these existing sensing technologies, a sensor device having a specific function for detecting an object or advanced electronic circuit technology is required, and the higher the required performance, the more complicated the structure, resulting in high costs.

For example, as a proximity sensor capable of detecting an object such as a metal at a relatively long distance, the following products are sold in the market.

Long-distance type proximity sensor TL-L of Oulongson company

http：//www.fa.omron.co.jp/products/family/479/lineup.html

Crohn's company proximity sensor

https：//www.keyence.co.jp/products/sensor/proximity/

These sensors can detect an object in a distance of about several mm to several cm using a principle of detecting a change in a magnetic field caused by eddy current generated in the object by a high-frequency magnetic field. However, the target object is limited to a good conductor such as a metal, and only the proximity of the target object can be detected, and three-dimensional positional information cannot be obtained alone.

As a sensor capable Of obtaining three-dimensional position information, a device called a TOF camera (TOF) has been popular in recent years.

As the TOF camera, for example, the following products are sold in the market.

Panasonic Co Ltd

https：//panasonic.co.jp/es/pespl/products/new/tofcamera.html

Basler Co Ltd

https：//ttps：//www.baslerweb.com/jp/products/cameras/3d-cameras/time-of-flight-camera/tof640-20gm_850nm/

In principle, these sensors use a strong light source modulated at a high frequency and an electronic circuit using an image sensor or advanced technology, and therefore have a complicated structure and an increased cost compared with the above-described proximity sensor.

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

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open No. 2009-59528

Disclosure of Invention

Problems to be solved by the invention

However, the above-described conventional object detection sensor has the following problems.

That is, the conventional object detection sensor has a limit in cost performance, and is configured to be able to detect objects other than metal over a relatively long distance, and therefore, the structure is necessarily complicated, which leads to an increase in cost.

The invention provides an object detection sensor and an object detection system capable of acquiring position information of an object with a simple structure.

Means for solving the problems

The object detection sensor according to the invention 1 detects a change in effective dielectric constant around a detection line based on a signal obtained from a change in propagation delay time of a signal transmitted to the detection line, and detects the presence or absence of an object in the vicinity of the detection line or position information of an object in which the detection line moves, and includes a plurality of detection lines, a transmitting unit, a receiving unit, a detecting unit, and a position information estimating unit. The transmitting unit transmits signals to the plurality of detection lines. The receiving unit receives the obtained signals from the plurality of detection lines, respectively. The detection unit detects propagation delay times of signals from the plurality of detection lines received in the reception unit. The position information estimating unit estimates position information of the object based on a balance (balance) of signals obtained from a change in propagation delay time of signals received from the plurality of detecting lines detected in the detecting unit.

Here, when an object is present in the vicinity of the detection line, the propagation delay time of the signals transmitted to the plurality of detection lines is detected by using the case where the effective dielectric constant of the surroundings of the detection line is changed, and the propagation delay time of each detection line is changed. Then, the position information of the object is estimated based on the balance of signals obtained from the changes in the propagation delay times detected in the plurality of detection lines.

Here, the detection line is an electrical linear member having an input unit to which an electrical signal is input and an output unit to which the signal is output, and has, for example, a meandering (pulse) shape or a linear shape.

The position information of the object estimated by the position information estimating unit includes not only the angle of the object observed 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 electrical signal propagates in an electrical wire depends on the spatial permittivity of the surroundings of the electrical wire. The dielectric constant is not necessarily uniform in space, and the strength of the electric field generated by the electric signal also depends on the distance from the electric wire, and therefore, the propagation speed is determined substantially based on the amount (effective dielectric constant) by which they are weighted and averaged in the whole space. It is considered that the dielectric constant of air is almost the same as that of vacuum, but in general, the dielectric constant of a substance is larger than that of air, and the ratio of the dielectric constant of air to that of vacuum (relative dielectric constant) is, for example, about 2 to 4 in a plastic-series material, and many materials show a value of about 1 bit. On the other hand, the dielectric constant of a substance containing polar molecules such as water or alcohol represents a large value of several 10 or more.

In addition, a material having good conductivity like a metal can be equivalently regarded as having an infinite relative dielectric constant. Therefore, if an object is present in the vicinity of the electric wire, the effective dielectric constant of the space around the electric wire becomes larger than in the case where no object is present. Thereby, the propagation delay time of the electric signal conducted in the electric wire becomes large.

In the object detection sensor of the present invention, such an electric wire that inputs and outputs an electric signal is used as a detection line, and a time difference (propagation delay time) between when signals are transmitted to a plurality of detection lines and when signals travel back through the lines is measured, and a balance of signals obtained from a change in the propagation delay time is detected.

By this means, it is possible to estimate positional information such as the position and direction of an object by detecting whether the object is near the plurality of detection lines or at a position closest to the plurality of detection lines, based on the balance of signals indicating changes in propagation delay time in the plurality of detection lines.

Further, as long as the material, the size, the shape, and the like of the object are known, for example, even in the case where 2 detection lines are used, the distance from the detection line to the object can be estimated.

The object detection sensor according to claim 2 is the object detection sensor according to claim 1, wherein the plurality of detection lines includes a 1 st line and a 2 nd line.

Here, the object detection sensor is constituted by using 2 detection lines (1 st line and 2 nd line).

Thus, based on the balance of the signals indicating the changes in propagation delay time of the signals inputted to the 2 detection lines (the 1 st line and the 2 nd line), the position information such as the distance from the 1 st line and the 2 nd line to the object, the direction, and the like can be estimated.

The object detection sensor according to claim 3 is the object detection sensor according to claim 2, wherein the 1 st line and the 2 nd line have substantially the same shape and substantially the same size, and are disposed with a predetermined distance therebetween.

The 1 st line and the 2 nd line having substantially the same shape and size are disposed with a predetermined distance therebetween.

Thus, since the 1 st line and the 2 nd line have substantially the same shape and substantially the same size, when an object is present at substantially the same distance from the 1 st line and the 2 nd line, propagation delay times in both lines are substantially the same.

Therefore, from the balance of the signals indicating the changes in propagation delay time in the 1 st line and the 2 nd line, the position information of the object can be easily estimated.

The object detection sensor according to the 4 th aspect of the present invention is the object detection sensor according to the 2 nd or 3 rd aspect of the present invention, wherein the position information estimating unit estimates an angle at which the object exists with respect to a straight line connecting the 1 st and 2 nd aspects based on a balance of signals obtained from the 1 st and 2 nd aspects.

Here, the angle (direction) at which the object exists with respect to the 1 st line and the 2 nd line is estimated from the balance of the signals indicating the propagation delay times obtained in the 1 st line and the 2 nd line, respectively.

Thus, it is possible to estimate whether or not an object is present in the vicinity of the 1 st line and the 2 nd line, and, for example, if the material, the size, the shape, and the like of the object are known, it is possible to estimate the distance to the object.

The object detection sensor according to claim 5 is the object detection sensor according to any one of claims 2 to 4, wherein the position information estimating unit estimates the distance to the object using a sum of balanced sum signals of signals obtained from the 1 st line and the 2 nd line.

Here, the direction in which the object exists is estimated based on the balance of the signals obtained from the 1 st line and the 2 nd line, and the distance to the object is estimated based on the sum of the signals (voltage values, etc.) thereof.

Thus, the direction and distance of the object existing nearby can be estimated from the simplified configuration using the 1 st line and the 2 nd line.

The object detection sensor according to claim 6 is the object detection sensor according to claim 1, wherein the plurality of detection lines includes a 1 st line, a 2 nd line, a 3 rd line, and a 4 th line.

Here, the object detection sensor is constituted by using 4 detection lines (1 st line to 4 th line).

Thus, the positional information such as the distance from the 1 st line to the 4 th line to the object, the direction, and the like can be estimated based on the balance of the signals in the 1 st line and the 2 nd line, the balance of the signals in the 3 rd line and the 4 th line, and the like, among the signals indicating the changes in the propagation delay time of the signals inputted to the 4 detection lines (the 1 st line to the 4 th line), respectively.

The object detection sensor according to the 7 th invention is the object detection sensor according to the 6 th invention, and the 1 st, 2 nd, 3 rd and 4 th lines are arranged to be rotationally symmetrical at substantially 90 degree intervals.

Here, the 4 detection lines (1 st to 4 th lines) are arranged to be rotationally symmetrical about an axis arranged at the center of the lines at substantially 90 degree intervals.

Thus, for example, the 1 st line and the 2 nd line are arranged at the opposite positions, the 3 rd line and the 4 th line are arranged at the opposite positions, and the presence or absence of the presence of the object, the positional information, and the like can be estimated by using the signal balance in the 1 st line and the 2 nd line and the signal balance in the 3 rd line and the 4 th line.

The object detection sensor according to claim 8 is the object detection sensor according to claim 6 or claim 7, wherein the 1 st line and the 2 nd line are disposed to face each other with a predetermined distance therebetween, and the 3 rd line and the 4 th line are disposed to face each other with a predetermined distance therebetween.

Here, the 4 detection lines (1 st to 4 th lines) are arranged such that the distance between the 1 st line and the 2 nd line arranged to face each other and the distance between the 3 rd line and the 4 th line arranged to face each other are the same (1 st distance).

Thus, the 4 detection lines (1 st to 2 nd lines) can be arranged rotationally symmetrically around the intersection point of the straight line connecting the 1 st line and the 2 nd line and the straight line connecting the 3 rd line and the 4 th line.

Therefore, the presence or absence of the presence of the object, the positional information, and the like can be easily estimated using the signal balance in the 1 st line and the 2 nd line, and the signal balance in the 3 rd line and the 4 th line.

The object detection sensor according to claim 9 is the object detection sensor according to any one of claims 6 to 8, wherein the 1 st line, the 2 nd line, the 3 rd line, and the 4 th line have substantially the same shape and substantially the same size.

Here, the 4 detection lines (1 st line to 4 th line) have substantially the same shape and size.

Thus, since the 1 st line and the 2 nd line have substantially the same shape and substantially the same size, when an object is present at substantially the same distance from the 1 st line and the 2 nd line, propagation delay times in both lines are substantially the same. Also, since the 3 rd line and the 4 th line have substantially the same shape and substantially the same size, the propagation delay time in the 3 rd line and the 4 th line is substantially the same in the case where objects exist at substantially the same distance from the two lines.

Therefore, the position information of the object can be easily estimated based on the balance of the signals indicating the changes in the propagation delay times in the 1 st line and the 2 nd line and the balance of the signals indicating the changes in the propagation delay times in the 3 rd line and the 4 th line.

The object detection sensor according to the 10 th aspect of the present invention is the object detection sensor according to any one of the 6 th to 9 th aspects of the present invention, wherein the position information estimating unit estimates the position of the object based on the balance of the signals obtained from the 1 st and 2 nd lines and the balance of the signals obtained from the 3 rd and 4 th lines.

Here, the direction of the object and the distance to the object are estimated based on the balance of the signals obtained from the 1 st line and the 2 nd line and the balance of the signals obtained from the 3 rd line and the 4 th line.

Thus, by a simplified configuration in which the 1 st line and the 2 nd line, the 3 rd line, and the 4 th line are each provided as a group, the direction and distance of an object existing in the vicinity can be estimated.

The object detection sensor according to claim 11 is the object detection sensor according to claim 16, wherein the plurality of detection lines are formed in a substantially straight line shape and are arranged substantially parallel to each other.

Here, the plurality of detection lines formed in a substantially straight line shape are arranged substantially parallel to each other.

Thus, by detecting a change in signal balance in a plurality of detection lines arranged substantially parallel to each other, the position of an object in a direction orthogonal to the plurality of detection lines can be estimated.

The object detection system according to the 12 th invention includes: the 1 st system including the object detection sensor according to any one of the 11 th inventions, and the 2 nd system including the object detection sensor according to any one of the 11 th inventions.

Here, the object detection system is constituted to include 2 systems (1 st system and 2 nd system) including a plurality of detection lines formed in a straight line and arranged substantially parallel to each other.

Here, the signal balance representing the change in propagation delay time detected in the 1 st system and the 2 nd system respectively is collected to the position information estimating unit included in the 1 st system or the 2 nd system, and the position information of the object is estimated.

Thus, the position information of the object can be estimated using 2 systems including a plurality of linear detection lines each arranged substantially parallel to each other.

The object detection system according to claim 13 is the object detection system according to claim 12, wherein the 1 st system and the 2 nd system are arranged so that a plurality of detection lines formed in a substantially straight line are substantially orthogonal to each other.

Here, 2 systems (system 1 and system 2) including a plurality of detection lines formed in a straight line and arranged substantially parallel to each other are arranged such that the plurality of detection lines in a straight line are substantially orthogonal to each other.

Thus, the positional information of the object can be easily estimated based on the signal balances detected in the 1 st system and the 2 nd system which are arranged to overlap in a substantially orthogonal manner.

The object detection system according to the 14 th aspect is the object detection system according to the 12 th or 13 th aspect, wherein the position information estimating unit estimates the position of the object based on the balance of signals obtained from the plurality of detection lines included in the 1 st aspect and the balance of signals obtained from the plurality of detection lines included in the 2 nd aspect.

Here, in the position information estimating unit included in the 1 st system or the 2 nd system, the position of the object is estimated based on the balance of the signals obtained in the 1 st system and the balance of the signals obtained in the 2 nd system.

The object detection system according to the 15 th invention is the object detection system according to the 12 th invention, and further includes a 3 rd system including the object detection sensor according to the 11 th invention.

Here, the object detection system includes not only 2 systems (1 st system and 2 nd system) including a plurality of detection lines formed in a straight line and arranged substantially parallel to each other, but also 3 rd system (3 rd system).

Thus, the position information of the object can be estimated based on the signal balances detected in each of the 3 systems.

The object detection system according to claim 16 is the object detection system according to claim 15, wherein the 1 st, 2 nd and 3 rd systems are arranged so that a plurality of detection lines formed in a substantially straight line cross each other at an angle of substantially 120 degrees.

Here, the 3 systems (1 st to 3 rd systems) are arranged such that a plurality of substantially linear detection lines intersect each other at an angle of substantially 120 degrees.

Thus, the positional information of the object can be easily estimated based on the signal balances detected in the 3 systems (1 st to 3 rd systems) which are arranged to overlap each other so as to intersect at an angle of approximately 120 degrees.

An object detection system according to claim 17 is the object detection system according to claim 15, wherein the 3 rd system is configured such that a plurality of detection lines formed in a substantially straight line cross each other at an angle of substantially 45 degrees with respect to the 1 st system and the 2 nd system in which the plurality of detection lines formed in a substantially straight line are substantially orthogonal to each other.

Here, the 3 rd system (3 rd system) is disposed so that the plurality of detection lines formed in a straight line intersect at an angle of approximately 45 degrees with respect to the 2 systems (1 st system and 2 nd system) including the plurality of detection lines formed in a straight line and disposed approximately in parallel.

Thus, for example, even when a plurality of objects exist in the vicinity of the 1 st to 3 rd systems, the positional information of each object can be estimated based on the signal balances detected in the 3 systems.

An object detection system according to an 18 th aspect of the present invention is the object detection system according to any one of the 15 th to 17 th aspects of the present invention, wherein the position information estimating unit estimates the position of the object based on the balance of signals obtained from a plurality of detection lines included in the 1 st aspect, the balance of signals obtained from a plurality of detection lines included in the 2 nd aspect, and the balance of signals obtained from a plurality of detection lines included in the 3 rd aspect.

Here, the positional information of the object is estimated using a signal balance indicating a change in propagation delay time obtained in 3 systems (1 st to 3 rd systems).

Thus, the position information of the object can be easily estimated based on the signal balances detected in the 3 systems, respectively.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the object detection sensor of the present invention, the position information of the object can be obtained with a simple structure.

Drawings

Fig. 1 is a control block diagram showing a configuration of an object detection sensor according to an embodiment of the present invention.

Fig. 2 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.

Fig. 3 is an explanatory diagram showing a detection principle of object position information using the object detection sensor of fig. 1.

Fig. 4 is a graph showing the relationship between the distance and the output voltage in the case where the brass round bar of fig. 3 is located on the front surface of the line of each channel (channel).

Fig. 5 is a graph showing the results of examining the change in the output voltage of each channel by changing X and Y in fig. 3.

Fig. 6 is a diagram showing a relationship between the intervals of the lines of the 2 channels of fig. 3 and the distances from the respective lines to the object.

Fig. 7 is a diagram showing a structure of an object detection system including an object detection sensor according to another embodiment of the present invention.

Fig. 8 is a diagram showing a structure of an object detection system including an object detection sensor according to still another embodiment of the present invention.

Fig. 9 is a diagram showing a structure of an object detection system including an object detection sensor according to still another embodiment of the present invention.

Fig. 10 is a diagram showing a structure of an object detection system including an object detection sensor according to still another embodiment of the present invention.

Detailed Description

(embodiment 1)

The object detection sensor 1 according to an embodiment of the present invention will be described below with reference to fig. 1 to 6.

The object detection sensor 1 according to the present embodiment is a sensor for detecting an object 30 (see fig. 2) existing in the vicinity of a plurality of detection lines 20 (1 st line 21 and 2 nd line 22), and includes a circuit unit 10 and a detection line 20 as shown in fig. 1.

Specifically, the object detection sensor 1 of the present embodiment detects propagation delay times in the respective detection lines (1 st line 21 and 2 nd line 22) by using a case where propagation delay times of signals transmitted to the plurality of detection lines (1 st line 21 and 2 nd line 22) change due to a change in effective dielectric constants around the detection lines (1 st line 21 and 2 nd line 22) when an object is present in the vicinity of the plurality of detection lines (1 st line 21 and 2 nd line 22). Then, the object detection sensor 1 estimates positional information of the object 30 (see fig. 2) based on the balance of signals obtained from the changes in the propagation delay time detected in the plurality of detection lines (the 1 st line 21 and the 2 nd line 22).

As shown in fig. 1, the circuit unit 10 includes: 1 st pulse generating section 11a, 1 st transmitting section 12a, 1 st receiving section 13a, 1 st detecting section 14a, 2 nd pulse generating section 11b, 2 nd transmitting section 12b, 2 nd receiving section 13b, 2 nd detecting section 14b, and position information estimating section 15.

The 1 st pulse generating unit 11a generates a pulse signal to be sent to the 1 st line 21.

The 1 st transmitting unit 12a transmits the pulse signal generated in the 1 st pulse generating unit 11a to the 1 st line 21 and the 1 st detecting unit 14 a.

The 1 st receiving unit 13a receives the pulse signal transmitted from the 1 st transmitting unit 12a to the 1 st line 21 and the pulse signal propagated through the 1 st line 21.

The 1 st detecting section 14a compares the pulse signal sent from the 1 st sending section 12a with the pulse signal received by the 1 st receiving section 13a, and detects the propagation delay time of the pulse signal.

The 2 nd pulse generating unit 11b generates a pulse signal to be sent to the 2 nd line 22.

The 2 nd transmitting unit 12b transmits the pulse signal generated in the 2 nd pulse generating unit 11b to the 2 nd line 22 and the 2 nd detecting unit 14 b.

The 2 nd receiving unit 13b receives the pulse signal transmitted from the 2 nd transmitting unit 12b to the 2 nd line 22 and the pulse signal propagated through the 2 nd line 22.

The 2 nd detecting means 14b compares the pulse signal sent from the 2 nd transmitting means 12b with the pulse signal received in the 2 nd receiving means 13b, and detects the propagation delay time of the pulse signal.

The position information estimating unit 15 receives the propagation delay times of the pulse signals detected by the 1 st detecting unit 14a and the 2 nd detecting unit 14b, and estimates the position information of the object 30 with respect to the 1 st line 21 and the 2 nd line 22 (see fig. 2) based on the balance of the changes in the propagation delay times in the 1 st line 21 and the 2 nd line 22.

Here, the position information of the object 30 estimated by the position information estimating unit 15 includes not only the relative positions with respect to the 1 st line 21 and the 2 nd line 22, but also position information indicating whether or not the object 30 exists in the vicinity of the 1 st line 21 and the 2 nd line 22.

The principle of estimating the positional information of the object 30 in the vicinity of the 1 st line 21 and the 2 nd line 22 will be described in detail in the following section.

In order to detect the propagation delay time of the signals transmitted to the plurality of lines (the 1 st line 21 and the 2 nd line 22) by using the change in the effective dielectric constant of the surroundings when the object 30 (see fig. 2) exists nearby, the detection line 20 detects the propagation delay time in each line (the 1 st line 21 and the 2 nd line 22) and is provided at a predetermined position, and includes the 1 st line 21 and the 2 nd line 22 as shown in fig. 1.

As shown in fig. 2, the 1 st line 21 and the 2 nd line 22 are formed by laying metal wires having meandering shapes (pulse shapes) of substantially the same shape and substantially the same dimensions in a sheet shape. The 1 st line 21 and the 2 nd line 22 are formed by sandwiching a metal wire between 2 insulating films. This can prevent noise from being generated by contact with another conductor.

Further, as the 1 st line 21 and the 2 nd line 22, a structure in which an insulating-coated metal wire is sandwiched by a cloth-like or net-like sheet may be used instead of the insulating film.

The 1 st line 21 has an input unit to which a pulse signal is input from the 1 st transmitting unit 12a, and an output unit to which a pulse signal is output to the 1 st receiving unit 13 a.

The 2 nd line 22 includes an input unit to which a pulse signal is input from the 2 nd transmitting unit 12b, and an output unit to which a pulse signal is output to the 2 nd receiving unit 13 b.

As shown in fig. 1, the object detection sensor 1 of the present embodiment transmits a pulse signal to the 1 st line 21, receives the pulse signal propagated through the 1 st line 21, detects a propagation delay time, transmits a pulse signal to the 2 nd line 22, receives the pulse signal propagated through the 2 nd line 22, and detects a propagation delay time. Then, signals indicating changes in propagation delay time in the 1 st line 21 and the 2 nd line 22 are compared, and based on the balance thereof, it is estimated whether or not there is an object 30 in the vicinity of the 1 st line 21 and the 2 nd line 22, or positional information of the object 30 such as the direction (angle) of the object 30 and the distance of the object 30.

Here, the distance between the object 30 as the detection target and each of the detection lines (the 1 st line 21 and the 2 nd line 22) varies according to the position of the object 30. Therefore, the signals indicating the change in the propagation delay time of the pulse signal obtained from the respective detection lines (the 1 st line 21 and the 2 nd line 22) are compared, and based on the balance thereof, the direction (angle) in which the object 30 exists with respect to the straight line connecting the 2 detection lines (the 1 st line 21 and the 2 nd line 22) can be estimated.

Thus, it is possible to estimate whether or not the object 30 approaches the vicinity of the 1 st line 21 and the 2 nd line 22, the direction (angle) of the object 30, or the position of which of the 1 st line 21 and the 2 nd line 22 the object 30 is in, based on the balance of the signals indicating the changes in propagation delay time in the plurality of detection lines (the 1 st line 21 and the 2 nd line 22).

As a result, by using the case where the effective dielectric constants of the surroundings of the 1 st line 21 and the 2 nd line 22 change when the object 30 approaches, it is possible to estimate positional information such as the position and the direction of the object 30 using a simplified structure such as the 1 st line 21 and the 2 nd line 22 made of a metal wire or the like.

In the object detection sensor 1 of the present embodiment, as shown in fig. 2, the detection lines (1 st line 21 and 2 nd line 22) having substantially the same shape and substantially the same size are arranged at predetermined positions with a predetermined distance therebetween.

Thus, when the object 30 is equidistant from the 1 st line 21 and the 2 nd line 22, the delay time after the pulse signals propagated through the 1 st line 21 and the 2 nd line 22 is substantially the same in the 1 st receiving unit 13a and the 2 nd receiving unit 13 b. Thus, when the object 30 approaches one of the 1 st line 21 and the 2 nd line 22, a difference occurs in propagation delay time between the 1 st line 21 and the 2 nd line 22, and thus the direction (angle) in which the object 30 exists with respect to the straight line connecting the 1 st line 21 and the 2 nd line 22 can be easily 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 signals obtained from 2 detection lines (the 1 st line 21 and the 2 nd line 22).

That is, if the object 30 approaches the 1 st line 21 and the 2 nd line 22, the change in effective dielectric constant around the 1 st line 21 and the 2 nd line 22 becomes large. As a result, propagation delay time of the pulse signals in the 1 st line 21 and the 2 nd line 22 increases according to the change in effective dielectric constants around the 1 st line 21 and the 2 nd line 22.

Thus, when the object 30 is located closer to the 1 st line 21 and the 2 nd line 22, the effective dielectric constants around the 1 st line 21 and the 2 nd line 22 change greatly, and the distances from the 1 st line 21 and the 2 nd line 22 to the object 30 can be estimated by using the sum of signals indicating that the propagation delay time of the pulse signals changes greatly.

The estimation of the distances from the 1 st line 21 and the 2 nd line 22 to the object 30 may be performed based on the material, the size, and the like of the object 30 that are recognized in advance, instead of using the sum of signals indicating the propagation delay times.

< principle of detection of position information on object >

The principle of estimating the position information of the object 30 by the object detection sensor 1 according to the present embodiment will be described below with reference to fig. 3 to 6.

Here, as shown in fig. 3, one end of a parallel wire (length 160 mm) composed of 2 wires having a coated outer diameter of about 1mm was short-circuited and turned back to be used as a detection wire. Then, 2 identical wires (1 st and 2 nd wires 21 and 22) were arranged in parallel with a space of 40mm, one of them being a-ch (1 st wire 21) and the other being B-ch (2 nd wire 22).

Then, as the object 30, a columnar brass round bar having a diameter of 30mm and a length of 50mm was assumed.

As shown in fig. 3, the brass round bar (object 30) was brought close to a-ch (line 1, 21) and B-ch (line 2, 22), and signals obtained from the changes in propagation delay time of the pulse signals in the respective lines 21, 22 were measured.

As shown in fig. 3, the position of the brass round bar is assumed to be expressed in terms of distance X in the direction of the straight line from the midpoint of the straight line connecting a-ch (1 st line 21) and B-ch (2 nd line 22) and height Y from the straight line.

The relationship between the height Y of the brass round bar (object 30) at the front side (on the midpoint of the straight line connecting the 1 st line 21 and the 2 nd line 22) of each channel (the 1 st line 21 and the 2 nd line 22) and the output voltage from each channel (the 1 st line 21 and the 2 nd line 22) is represented by the graph shown in fig. 4.

As shown in the graph, the output voltages of the channels (1 st line 21 and 2 nd line 22) are approximately inversely proportional to the height Y. Thus, the relationship between the output voltage and the distance r to the brass round bar (object 30) can be expressed approximately as

s＝k/r。

Here, k is a constant.

Next, the results of examining the changes in the output voltages of the respective channels (the 1 st line 21 and the 2 nd line 22) are shown in fig. 5, with changing X and Y.

In the graph shown in fig. 5, the output voltages from the 2 channels (1 st line 21 and 2 nd line 22) have a shape that is almost right-left symmetrical with respect to the position of the midpoint (x=0) of the 2 lines (1 st line 21 and 2 nd line 22). It is also understood that the output voltage of each channel is maximum when the brass round bar (object 30) is located on the front surface of each channel (1 st line 21 and 2 nd line 22) (a-ch is x= -2cm, and B-ch is x=2 cm), and decreases as the brass round bar deviates from the front surface, and the output voltage decreases as the distance increases.

Therefore, it is known that based on the magnitude and balance of the output signals of the 2 channels (the 1 st line 21 and the 2 nd line 22), the positional information about the distance and direction (angle) to the brass round bar (the object 30) can be estimated.

Here, as shown in fig. 6, if the interval between 2 channels (1 st line 21 and 2 nd line 22) is d and the distances from the channels (1 st line 21 and 2 nd line 22) to the object 30 are r1 and r2, then the relationship between these passes

[ 1 ]

[ 2 ]

To represent.

If it is arranged, it is

[ 3 ] of the following

[ 4 ] of the following

If the outputs of the respective lines are S1 and S2, S1 and S2 are expressed by the following equations.

[ 5 ]

[ 6 ]

Using these formulae, the product is

[ 7 ]

Since k and d are known, r can be found from S1 and S2.

Since these can be expressed by the following expression, the angle θ of the object 30 with respect to each channel (the 1 st line 21 and the 2 nd line 22) can be obtained based on r that has been already obtained.

[ 8 ] of the following

In the object detection sensor 1 of the present embodiment, as described above, the electronic circuit (the circuit unit 10, the 1 st line 21, the 2 nd line 22, and the like) for realizing object detection is constituted by a combination of only standard semiconductor devices.

Thus, the function of three-dimensional object detection can be realized with a simplified structure and at 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, in the object detection sensor 101 of the present embodiment, 4 detection lines (1 st line 121, 2 nd line 122, 3 rd line 123, and 4 th line 124) having substantially the same shape and substantially the same size are arranged rotationally symmetrically at substantially 90-degree intervals in the circumferential direction equidistant from the center of the circular plate. In the object detection sensor 101, the change in propagation delay time of the pulse signal is measured from each of the detection lines (1 st line 121, 2 nd line 122, 3 rd line 123, and 4 th line 124).

Then, based on the sum of the signals obtained from the 4 detection lines (1 st line 121 to 4 th line 124), position information on the presence or absence of the object 30 and the distance from the center of each detection line is estimated.

More specifically, the position information of which direction (angle) the object 30 is present in is estimated on the surface connecting the 1 st line 121 and the 2 nd line 122, based on the difference in the magnitudes of the signals indicating the propagation delay times in the 1 st line 121 and the 2 nd line 122 arranged at the positions facing each other.

Similarly, positional information about the direction (angle) in the plane connecting the 3 rd line 123 and the 4 th line 124 is estimated from the difference in the magnitudes of signals indicating the propagation delay times in the 3 rd line 123 and the 4 th line 124 arranged at the positions opposed to each other.

By combining these positional information on the directions (angles), the three-dimensional arrangement of the object 30 can be easily estimated.

Here, if the direction from the 1 st line 121 toward the 2 nd line 122 is the X axis, the direction from the 3 rd line 123 toward the 4 th line 124 is the Y axis, and the plane including the relatively upward line is the Z axis, the direction (angle) in which the object 30 exists with respect to the plane including the Y axis can be estimated from the balance between the signal output from the 1 st line 121 and the signal output from the 2 nd line 122. If the estimated angle is set to θ, the face passes

[ 9 ] of the invention

Such a formula represents.

Also, based on the balance of the signal output from the 3 rd line 123 and the signal output from the 4 th line 124, it is possible to estimate the direction (angle) in which the object exists with respect to the plane including the X-axis, and if the angle is set to Φ, the plane is expressed as

[ 10 ] of the following

As a result, the intersection of these 2 faces is

[ 11 ]

It can be estimated that the object 30 is present on the straight line.

That is, based on the balance of the signals output from the respective detection lines (1 st line 121 to 4 th line 124), the distance from the center point of the circumferential direction in which the 1 st line 121 to 4 th line 124 are arranged to the object 30 can be estimated.

Therefore, by configuring the object detection sensor 101 using 4 detection lines (1 st line 121 to 4 th line 124), the three-dimensional position of the object 30 can be easily estimated.

Embodiment 3

An object detection system 250 including object detection sensors (system 1) 201a to 201c according to still another embodiment of the present invention will be described below with reference to fig. 8.

In the system configuration shown in fig. 8, only the line portions of the object detection sensor (system 1) 201a including the plurality of lines A1 to A8 formed in a straight line, the object detection sensor (system 2) 201B including the plurality of lines B1 to B8 formed in a straight line, and the object detection sensor (system 3) 201C including the plurality of lines C1 to C8 formed in a straight line are shown for convenience of description. However, in an actual configuration, the plurality of lines A1 to A8 each have an input unit and an output unit, respectively, and as shown in fig. 1, the following configuration is assumed: pulse signals are output to the lines A1 to A8, the pulse signals after propagation are received, propagation delay time is detected, and 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 includes: an object detection sensor 201a having a plurality of lines A1 to A8 formed in a straight line, an object detection sensor 201B having lines B1 to B8, and an object detection sensor 201C having lines C1 to C8.

In the object detection sensor 201a, a plurality of lines A1 to A8 formed in a straight line are arranged at equal intervals and substantially parallel to each other.

In the object detection sensor 201B, a plurality of lines B1 to B8 formed in a straight line are arranged at equal intervals and substantially parallel to each other.

In the object detection sensor 201C, a plurality of lines C1 to C8 formed in a straight line are arranged at equal intervals and substantially parallel to each other.

Then, as shown in fig. 8, the object detection sensors 201a to 201C are arranged such 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.

Thus, it is possible to easily estimate which of the lines A1 to A8, B1 to B8, and C1 to C8 the object 30 is present closest to, from the distribution of the magnitudes of the signals obtained as the outputs of the lines A1 to A8, B1 to B8, and C1 to C8 included in the object detection sensors 201a to 201C.

As a result, by comprehensively using the signal balances obtained from the 3 systems (the object detection sensors 201a to 201 c), the coordinates of the foot of the vertical line downward from the object 30 on the surface including each system can be estimated. Further, the distances from the lines A1 to A8, the lines B1 to B8, and the lines C1 to C8 to the object 30 can be estimated based on the magnitudes of the absolute values of the respective signals.

In the example of fig. 8, each of the detection line groups A, B, C is composed of 8 lines A1 to A8, lines B1 to B8, and lines C1 to C8, and these lines are denoted as Ai, bj, and Ck (i, j, k=1 to 8).

In the object detection system 250 of the present embodiment, 8 lines A1 to A8, lines B1 to B8, and lines C1 to C8 included in the respective object detection sensors 201a to 201C are arranged to intersect at an angle of about 120 degrees to each other.

Therefore, 88 is formed in the substantially triangular region surrounded by the lines A1 to A8, the lines B1 to B8, and the lines C1 to C8. In these substantially triangular regions, when the object 30 is present in the region, the outputs of the lines Ai, bj, ck surrounding the region become large.

This makes it possible to easily estimate the position information such as the distance and direction from each line Ai, line Bj, and line 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 fig. 9 and 10.

In the system configuration shown in fig. 9, only the line portion of the object detection sensor (system 1) 301a including the plurality of lines A1 to A8 formed in a straight line and the object detection sensor (system 2) 301B including the plurality of lines B1 to B8 formed in a straight line are shown for convenience of description. However, in an actual configuration, the plurality of lines A1 to A8 each have an input unit and an output unit, respectively, and as shown in fig. 1, the following configuration is assumed: pulse signals are output to the lines A1 to A8, the pulse signals after propagation are received, propagation delay time is detected, and 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 (system 1) 301a and an object detection sensor (system 2) 301b.

In the object detection sensor 301a, a plurality of lines A1 to A8 formed in a straight line are arranged at equal intervals and substantially parallel to each other.

In the object detection sensor 301B, a plurality of lines B1 to B8 formed in a straight line are arranged at equal intervals and substantially parallel to each other.

Then, as shown in fig. 9, the object detection sensors 301a and 301B are arranged such that the lines A1 to A8 and the lines B1 to B8 intersect each other at an angle of substantially 90 degrees.

Thus, it is possible to easily estimate which of the lines A1 to A8 and B1 to B8 the object 30 is present at closest positions from the distribution of the magnitudes of the signals obtained as the outputs of the lines A1 to A8 and B1 to B8 included in the object detection sensors 301a and 301B.

Here, for example, in the case where the object 330a is only one, it is possible to estimate coordinates of the feet of the vertical line downward from the object 330a on the surface including the line group (the lines A1 to A8 or the lines B1 to B8), and it is possible to realize the object detection sensor 301a, 301B as 2 systems.

However, for example, as shown in fig. 9, when there are a plurality of objects 330a and 330B, the object 330a is present at a position closest to the line A2 among the lines A1 to A8 and closest to the line B3 among the lines B1 to B8.

Therefore, the position information of the object 330a can be easily estimated from the fact that the signals indicating the propagation delay times outputted from these lines A2 and B3 become large.

Likewise, the object 330B exists at a position closest to the line A5 among the lines A1 to A8 and closest to the line B6 among the lines B1 to B8. Therefore, the position information of the object 330B can be easily estimated from the fact that the signals indicating the propagation delay times outputted from these lines A5 and B6 become large.

However, in the configuration of the present embodiment, as shown in fig. 9, if a plurality of objects 330a and 330B are present in the vicinity of the lines A1 to A8 and the lines B1 to B8, if the signals indicating the propagation delay times output from the lines A2 and B6 become large, it is difficult to recognize that there is an object at the intersection of these 2 lines A2 and B6.

Similarly, when the signals output from the lines A5 and B3 become large, it is difficult to recognize that there is an object at the intersection of these 2 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 in the detection target range, it is estimated that there is an object as if there is actually no object position, and there is a problem of false detection of so-called ghost (ghost).

Therefore, in the object detection system 450 of the present embodiment, as shown in fig. 10, the lines A1 to A8 and the lines B1 to B8 of the 2 systems are arranged so as to intersect each other at substantially 90 degrees in the longitudinal and lateral directions, and the 3 rd lines C1 to C8 are arranged so as to intersect the lines A1 to A8 and the lines B1 to B8 at substantially 45 degrees.

This can solve the problem of erroneous detection of the ghost. In addition, compared with the example of the line arrangement crossing at an angle of approximately 120 degrees to each other described using fig. 8, the estimation of the position information of the objects 330a, 330b can be implemented by dividing the estimation into the checkered pattern. As a result, there is an advantage that the calculation can be simplified in addition to processing the coordinate data by the arithmetic expression.

Other embodiments

Although the 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 present invention.

(A)

In the above-described embodiment, the configuration in which a plurality of detection lines (1 st line 21 and 2 nd line 22) are sent from different transmission units (1 st transmission unit 12a and 2 nd transmission unit 12 b), signals are received by different reception units (1 st reception unit 13a and 2 nd reception unit 13 b), and propagation delay times are detected by different detection units (1 st detection unit 14a and 2 nd detection unit 14 b) has been described as an example. However, the present invention is not limited thereto.

For example, a signal may be transmitted from a single transmitting unit to a plurality of detecting lines, a signal from a plurality of detecting lines may be received by a single receiving unit, and each propagation delay time may be detected by a single detecting unit.

That is, the transmitting unit, the receiving unit, and the detecting unit may be provided separately for each of the plurality of detecting lines or may be shared as long as the position information estimating unit is shared.

In the case of using a common transmission unit, signals to be transmitted from the transmission unit to the respective detection lines may be transmitted at different timings.

(B)

In the above embodiment, the detection line is formed by a meandering shape (pulse shape) or a linear metal wire. However, the present invention is not limited thereto.

For example, the mode of the detection line is not limited to a meandering shape or a linear shape, and may be other shapes.

(C)

In the above-described embodiment, description has been given taking an example in which the presence or absence of the object existing in the vicinity of the detection line, the position information such as the direction and the distance, etc., is detected by the object detection sensor or the object detection system. However, the present invention is not limited thereto.

For example, the present 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 use of the object detection sensor.

(D)

In the above embodiment, in the description of the detection principle of the object position information, the example in which the brass round bar is used is described as the object 30. However, the present invention is not limited thereto.

For example, the object 30 whose position information can be detected by the present object detection sensor is not limited to a metal such as a brass round bar, and may be an object made of other materials such as resin, paper, liquid, and rubber, or a moving body such as a person or a passenger car.

(E)

In the above embodiment, an example in which 8 detection lines formed in a straight line are arranged substantially in parallel will be described. However, the present invention is not limited thereto.

For example, the number of the linear detection lines is not limited to 8, and may be increased or decreased depending on the application, the type of the object to be detected, and the like. The arrangement of the detection lines forming the straight lines is not limited to being substantially parallel, and may be, for example, disposed so as to intersect each other or disposed at a position apart from each other.

(F)

In the above-described embodiment, as shown in fig. 1, the 1 st pulse generating means 11a for generating the pulse signal transmitted to the 1 st line 21 and the 2 nd pulse generating means 11b for generating the pulse signal transmitted to the 2 nd line 22 are described as examples of different configurations. However, the present invention is not limited thereto.

For example, the 1 st pulse generating unit and the 2 nd pulse generating unit may be provided as a single pulse generating unit.

Industrial applicability

The object detection sensor according to the present invention has an effect of obtaining positional information of an object with a simple structure, and therefore can be widely applied to a proximity detection sensor of an object, and the like.

Description of the reference numerals

1. Object detection sensor

10. Circuit unit

11a 1 st pulse generating unit

11b pulse 2 generating unit

12a 1 st transmitting unit (transmitting unit)

12b 2 nd transmitting unit (transmitting unit)

13a 1 st receiving unit (receiving unit)

13b 2 nd receiving unit (receiving unit)

14a 1 st detection unit (detection unit)

14b 2 nd detection unit (detection unit)

15. Position information estimation unit

20. Circuit for detection

21. Line 1

22. Line 2

30. Object

101. Object detection sensor

121. Line 1

122. Line 2

123. Line 3

124. Line 4

201a object detection sensor (1 st system)

201b object detection sensor (System 2)

201c object detection sensor (System 3)

250. Object detection system

301a object detecting sensor (1 st system)

301b object detecting sensor (System 2)

330a,330b object

350. Object detection system

401a object detecting sensor (1 st system)

401b object detecting sensor (System 2)

401c object detecting sensor (System 3)

450. Object detection system

A1 to A8 lines (lines for detection)

B1 to B8 lines (lines for detection)

C1-C8 circuits (circuits for detection)

Claims

1. An object detection sensor that detects a change in effective dielectric constant around a detection line based on a signal obtained from a change in propagation delay time of a signal transmitted to the detection line, and detects position information of an object including the presence or absence of or movement of an object near the detection line, the object detection sensor comprising:

a plurality of the detection lines including metal wires having substantially the same shape and substantially the same size;

a transmitting unit configured to transmit the signals to the plurality of detection lines;

a receiving unit configured to receive the signals obtained from the plurality of detection lines, respectively;

a detection unit configured to detect propagation delay times of the signals received by the reception unit from the plurality of detection lines; and

a position information estimating unit that estimates the position information of the object based on a balance of signals obtained from a change in the propagation delay time of the signals received from the plurality of detecting lines detected in the detecting unit.

2. The object detection sensor according to claim 1,

the plurality of detection lines includes a 1 st line and a 2 nd line.

3. The object detection sensor according to claim 2,

the 1 st line and the 2 nd line are disposed with a predetermined distance therebetween.

4. The object detection sensor according to claim 2 or 3,

the position information estimating unit estimates an angle at which the object exists with respect to a straight line connecting the 1 st line and the 2 nd line, based on a balance of the signals obtained from the 1 st line and the 2 nd line.

5. The object detection sensor according to claim 2 or 3,

the position information estimating unit estimates a distance to the object using a balance of the signals obtained from the 1 st line and the 2 nd line and a sum of the signals.

6. The object detection sensor according to claim 1,

the plurality of detection lines includes a 1 st line, a 2 nd line, a 3 rd line, and a 4 th line.

7. The object detection sensor of claim 6,

the 1 st line, the 2 nd line, the 3 rd line, and the 4 th line are arranged to be rotationally symmetrical at substantially 90 degree intervals.

8. The object detection sensor according to claim 6 or 7,

the 1 st line and the 2 nd line are arranged to face each other with a predetermined distance of 1 st distance therebetween,

the 3 rd line and the 4 th line are disposed to face each other with a predetermined distance therebetween, the predetermined distance being the 1 st distance.

9. The object detection sensor according to claim 6 or 7,

the 1 st line, the 2 nd line, the 3 rd line, and the 4 th line have substantially the same shape and substantially the same size.

10. The object detection sensor according to claim 6 or 7,

the position information estimating unit estimates a position of the object based on a balance of the signals obtained from the 1 st line and the 2 nd line and a balance of the signals obtained from the 3 rd line and the 4 th line.

11. The object detection sensor according to claim 1,

the plurality of detection lines are formed in a substantially linear shape and are arranged substantially parallel to each other.

12. An object detection system comprising:

a system 1 comprising the object detection sensor of claim 11; and

a system 2 comprising the object detection sensor of claim 11.

13. The object detection system of claim 12,

The 1 st system and the 2 nd system are configured such that the plurality of detection lines formed in a substantially linear shape are substantially orthogonal to each other.

14. An object detection system according to claim 12 or 13,

the position information estimating unit estimates the position of the object based on the balance of the signals obtained from the plurality of detection lines included in the 1 st system and the balance of the signals obtained from the plurality of detection lines included in the 2 nd system.

15. The object detection system of claim 12,

further comprising a 3 rd system comprising the object detection sensor of claim 11.

16. The object detection system of claim 15,

the 1 st system, the 2 nd system, and the 3 rd system are configured such that the plurality of detection lines formed in a substantially straight line cross each other at an angle of substantially 120 degrees.

17. The object detection system of claim 15,

the 3 rd system is the 1 st system and the 2 nd system, which are arranged to be substantially orthogonal to each other with respect to the plurality of detection lines arranged to be substantially linear, and the plurality of detection lines arranged to be substantially linear are each intersected at an angle of substantially 45 degrees.

18. The object detection system according to any one of claim 15 to 17,

the position information estimating unit estimates the position of the object based on the balance of the signals obtained from the plurality of detection lines included in the 1 st system, the balance of the signals obtained from the plurality of detection lines included in the 2 nd system, and the balance of the signals obtained from the plurality of detection lines included in the 3 rd system.