Object detecting system, object detecting method, and program

Abstract

This object detecting system controls the sensitivity of a proximity sensor that includes a plurality of electrodes and that detects a target object on the basis of a change in capacitance, the object detecting system being characterized by additionally including: a circuit that connects the plurality of electrodes; a switching unit that switches between connection methods of the circuit connecting the plurality of electrodes; and a control unit that generates a switching instruction relating to the connection method of the circuit and outputs the switching instruction to the switching unit.

Description

Object detection system, object detection method, and program

[0001] This application claims priority to Japanese Patent Application No. 2024-026447, filed February 26, 2024, the contents of which are incorporated herein by reference.

[0002] Conventionally, there has been a capacitance-type detection sensor that detects the presence or absence of an object and the pressure exerted by the object (see, for example, Patent Document 1). This capacitance-type detection sensor includes a pair of first electrodes and a pair of second electrodes that are positioned farther from the contact surface of the substrate than the pair of first electrodes in a direction perpendicular to the contact surface of the substrate, overlapping the first electrodes and sandwiching the substrate. This capacitance-type detection sensor detects the proximity of an object to the contact surface of the substrate based on a measurement result of the capacitance between the pair of first electrodes, and detects the pressure acting on the substrate from the object in contact with the contact surface of the substrate based on a measurement result of the capacitance between the pair of second electrodes.

[0003] Japanese Patent Application Laid-Open No. 2021-060211

[0004] Capacitive proximity sensors (capacitive detection sensors) are required to have the ability to detect distant objects (hereinafter referred to as distance performance) and the ability to accurately detect the position of the object (hereinafter referred to as spatial resolution).However, generally, improving distance performance reduces spatial resolution, and vice versa, making it difficult to achieve both spatial resolution and distance performance, making it difficult to efficiently detect objects.

[0005] The present invention has been made in consideration of the above circumstances, and one of its objects is to enable efficient detection of target objects.

[0006] In order to solve the above problems and achieve the object, the present invention employs the following aspects: (1): An object detection system according to one aspect of the present invention is an object detection system that includes a plurality of electrodes and controls the sensitivity of a proximity sensor that detects a target object based on a change in capacitance, and further includes a circuit that connects the plurality of electrodes, a switching unit that switches how the circuit that connects the plurality of electrodes is connected, and a control unit that generates a switching instruction regarding how the circuit is connected and outputs the instruction to the switching unit.

[0007] (2) In the aspect (1) above, the control unit generates the switching instruction based on the detection result of the proximity sensor.

[0008] (3): In the aspect (1) above, the control unit generates the switching instruction to switch the way the circuit is connected so that the number of coupled electrodes formed by one or more connected electrodes increases and the area of ​​the coupled electrodes decreases when the distance to the target object is smaller than a preset threshold, and generates the switching instruction to switch the way the circuit is connected so that the number of coupled electrodes formed by one or more connected electrodes decreases and the area of ​​the coupled electrodes increases when the distance to the target object is larger than a preset threshold.

[0009] (4): In the above aspect (1) or (2), the electrodes are mounted on a robot that manipulates the target object, and the control unit generates the switching instruction to switch the way the circuit is connected so that, while approaching the target object, the number of coupled electrodes formed by one or more connected electrodes decreases and the area of ​​the coupled electrodes increases, and when grasping or manipulating the target object, the control unit generates the switching instruction to switch the way the circuit is connected so that the number of coupled electrodes formed by one or more connected electrodes increases and the area of ​​the coupled electrodes decreases.

[0010] (5): A detection method according to one aspect of the present invention is characterized in that a control unit that controls the sensitivity of a proximity sensor that has a plurality of electrodes and detects a target object based on a change in capacitance generates a switching instruction regarding how to connect a circuit connecting the plurality of electrodes and outputs it to a switching unit, changes a coupling electrode formed by one or a plurality of connected electrodes and the area of ​​the coupling electrode to control the sensitivity of the proximity sensor, and detects the target object using the proximity sensor.

[0011] (6): A program according to one aspect of the present invention is characterized in that it causes a control unit that has a plurality of electrodes and controls the sensitivity of a proximity sensor that detects a target object based on changes in capacitance to generate a switching instruction regarding how to connect a circuit that connects the plurality of electrodes and output it to the switching unit, change a coupled electrode formed by one or a plurality of connected electrodes and the area of ​​the coupled electrode to control the sensitivity of the proximity sensor, and detect the target object using the proximity sensor.

[0012] According to aspects (1) to (6), it is possible to efficiently detect a target object.

[0013] 1 is a diagram illustrating an example of the configuration of an object detection system 1 according to a first embodiment. FIG. 2 is a diagram illustrating an example of a usage mode of the transmitting and receiving electrodes 40. FIG. 3 is a diagram illustrating an example of a threshold value. FIG. 4 is a diagram illustrating how to connect the circuit in a first mode in a proximity sensor 20. FIG. 5 is a diagram illustrating an example of a measurement mode when the circuit of the proximity sensor 20 is connected in the first mode. FIG. 6 is a diagram illustrating how to connect the circuit in a second mode in the proximity sensor 20. FIG. 7 is a diagram illustrating an example of a measurement mode when the circuit of the proximity sensor 20 is connected in the second mode. FIG. 8 is a diagram illustrating how to connect the circuit in a third mode in the proximity sensor 20. FIG. 9 is a diagram illustrating an example of a measurement mode when the circuit of the proximity sensor 20 is connected in the third mode. FIG. 10 is a flowchart illustrating an example of processing by a control unit 10. FIG. 11 is a flowchart illustrating an example of processing by the control unit 10. FIG. 12 is a diagram illustrating an example of the configuration of an object detection system 2 according to a second embodiment. FIG. 13 is a diagram illustrating an example of a usage mode of the transmitting and receiving electrodes 60. FIG. 14 is a diagram illustrating how to connect the circuit in a proximity sensor 70 in the first mode. FIG. 15 is a diagram illustrating an example of a measurement mode when the circuit of the proximity sensor 70 is connected in the first mode. 1 is a diagram showing an example of a measurement mode when the circuit of the proximity sensor 70 is connected in the second mode. FIG. 2 is a diagram showing how to connect the circuit of the proximity sensor 70 in the third mode. FIG. 3 is a diagram showing an example of a measurement mode when the circuit of the proximity sensor 70 is connected in the third mode.

[0014] Hereinafter, an embodiment of an object detection system, an object detection method, and a program according to the present invention will be described with reference to the drawings.

[0015] <First Embodiment> Fig. 1 is a diagram showing an example of the configuration of an object detection system 1 according to the first embodiment. The object detection system 1 according to the first embodiment is a so-called self-capacitance type object detection system. The object detection system 1 includes, for example, a control unit 10, a proximity sensor 20, and a camera 30. The object detection system 1 is a system that detects an object approaching, for example, a human body or a robot.

[0016] In the object detection system 1 according to the embodiment, the sensitivity of the proximity sensor 20 is controlled based on the distance between the proximity sensor 20 and a target object, for example. The sensitivity of the proximity sensor 20 includes spatial resolution and distance performance. Increasing the sensitivity of the proximity sensor 20 means increasing the spatial resolution and decreasing the distance performance, and decreasing the sensitivity of the proximity sensor 20 means decreasing the spatial resolution and increasing the distance performance.

[0017] The proximity sensor 20 includes, for example, a switching unit 21, a measuring unit 22, a plurality of, for example, eight transmitting and receiving electrodes, the first transmitting and receiving electrode 41 to the eighth transmitting and receiving electrode 48, and a plurality of, for example, eight wires, the first wire 51 to the eighth wire 58. The first transmitting and receiving electrode 41 to the eighth transmitting and receiving electrode 48 are examples of electrodes. The first wire 51 to the eighth wire 58 form a circuit.

[0018] The switching unit 21 switches the connection of the first wiring 51 to the eighth wiring 58 that connect the first transmitting / receiving electrodes 41 to the eighth transmitting / receiving electrodes 48. A part of the circuit (the first wiring 51 to the eighth wiring 58) and the first transmitting / receiving electrodes 41 to the eighth transmitting / receiving electrodes 48 are included in a flexible and stretchable circuit device (F&S) mounted on, for example, a human body or a robot, such as a humanoid robot. In the embodiment, the F&S in the proximity sensor 20 is mounted on a robot hand that is part of a humanoid robot that manipulates a target object. The robot hand includes a first finger (thumb), a second finger (index finger), a third finger (middle finger), a fourth finger (ring finger), a fifth finger (pinky finger), and a first finger portion, a second finger portion, a third finger portion, a fourth finger portion, a fifth finger portion, and a palm portion that respectively correspond to the palm.

[0019] The first transmitting / receiving electrode 41 to the eighth transmitting / receiving electrode 48 are provided on the robot hand, with the first transmitting / receiving electrode 41 at the second joint of the second finger, the second transmitting / receiving electrode 42 at the third joint of the second finger, the third transmitting / receiving electrode 43 at the second joint of the third finger, the fourth transmitting / receiving electrode 44 at the third joint of the third finger, the fifth transmitting / receiving electrode 45 at the second joint of the fourth finger, the sixth transmitting / receiving electrode 46 at the third joint of the fourth finger, the seventh transmitting / receiving electrode 47 at the second joint of the fifth finger, and the eighth transmitting / receiving electrode 48 at the third joint of the fifth finger. The transmitting / receiving electrodes may be provided on a palm portion other than the fingers, for example. Furthermore, in the embodiment, eight transmitting / receiving electrodes are provided as an example, but the number of transmitting / receiving electrodes may be less than eight or more than eight.

[0020] The camera 30 is provided in a position that corresponds to the eyes of a humanoid robot, for example. The camera 30 captures an image of the surroundings. The image captured by the camera 30 includes a target object. The control unit 10 processes the image captured by the camera 30, and if it detects that the image includes a target object, it uses the results of the image processing to calculate the distance to the target object (hereinafter, the target distance).

[0021] The control unit 10 is realized by, for example, a hardware processor such as a CPU (Central Processing Unit) executing a program (software). Some or all of these components may be realized by hardware (including circuitry) such as an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a GPU (Graphics Processing Unit), or may be realized by a combination of software and hardware.

[0022] The program may be stored in advance in a storage device (a storage device with a non-transitory storage medium) such as an HDD (Hard Disk Drive) or flash memory, or may be stored in a removable storage medium (a non-transitory storage medium) such as a DVD or CD-ROM, and installed by inserting the storage medium into a drive device.

[0023] The control unit 10 generates a switching instruction based on the detection result of the proximity sensor 20. The control unit 10 acquires the target distance based on, for example, a proximity signal output by the measurement unit 22. The control unit 10 generates a control signal for controlling the operation of the robot hand and a switching instruction to be output to the switching unit 21 based on the acquired target distance. The control unit 10 controls the operation of the robot hand based on the generated control signal.

[0024] The control unit 10 generates a switching signal by specifying a mode (hereinafter, "coupling mode") set for each coupling pattern based on the acquired target distance. The coupling pattern is a pattern for coupling the first transmitting / receiving electrodes 41 to the eighth transmitting / receiving electrodes 48 (a way of connecting a circuit including the first wiring 51 to the eighth wiring 58 that connect the first transmitting / receiving electrodes 41 to the eighth transmitting / receiving electrodes 48 to the switching unit 21). The switching signal includes a switching instruction that specifies the coupling mode and instructs switching of the coupling pattern. The control unit 10 outputs the generated switching signal to the switching unit 21 of the proximity sensor 20.

[0025] The switching unit 21 in the proximity sensor 20 switches the coupling pattern by setting a coupling mode according to a switching instruction. For example, based on a switching instruction included in a switching signal output from the control unit 10, the switching unit 21 connects a coupling electrode formed by coupling (short-circuiting) eight transmitting and receiving electrodes to the measurement unit 22. The switching unit 21 includes, for example, switch circuits connected to each of the first wiring 51 to the eighth wiring 58.

[0026] In the switch circuit, ON / OFF is set for each coupling mode with each of the first wiring 51 to the eighth wiring 58. The switching unit 21 sets the coupling mode in accordance with a switching instruction included in a switching signal output by the control unit 10, and switches ON / OFF between the switch circuit and each of the first wiring 51 to the eighth wiring 58 in accordance with the coupling mode.

[0027] The measurement unit 22 calculates the target distance based on the proximity sensor signals output by the first transmitting / receiving electrode 41 to the eighth transmitting / receiving electrode 48. For example, the measurement unit 22 calculates a change in the proximity sensor value included in the proximity sensor signal output from the transmitting / receiving electrodes coupled by the switching unit 21 among the first transmitting / receiving electrode 41 to the eighth transmitting / receiving electrode 48, and when a change in the proximity sensor value is detected, calculates the target distance in accordance with the change in the proximity sensor value. If there are multiple coupled electrodes, the proximity sensor values ​​are acquired by switching between the multiple coupled electrodes in a predetermined time-shared measurement pattern. The transmitting / receiving electrodes not connected to the measurement unit 22 remain unconnected. The measurement unit 22 generates a proximity signal based on the calculated target distance and outputs it to the control unit 10.

[0028] The first transmitting and receiving electrode 41 to the eighth transmitting and receiving electrode 48 all have the same configuration. Fig. 2 is a diagram showing an example of how the transmitting and receiving electrode 40 is used. The first transmitting and receiving electrode 41 to the eighth transmitting and receiving electrode 48 are provided, for example, in the same manner as the transmitting and receiving electrode 40. The transmitting and receiving electrode 40 is provided, for example, on one side of a surface panel P of a robot hand. The transmitting and receiving electrode 40 is an electrode that generates an electric field indicated by electric force lines E and detects electrostatic capacitance.

[0029] For example, when a target object, such as a human hand H, approaches the front panel P, a pseudo-capacitor is generated between the electric field generated by the transmitting / receiving electrodes 40 and the human hand. The generation of the pseudo-capacitor changes the capacitance detected by the transmitting / receiving electrodes 40. The transmitting / receiving electrodes 40 detect the capacitance associated with the generation of the capacitor in the generated electric field. The transmitting / receiving electrodes 40 output a proximity sensor signal based on the detected capacitance to the measurement unit 22.

[0030] The control unit 10 controls the sensitivity of the proximity sensor 20 by specifying a coupling mode and causing the switching unit 21 to switch the coupling pattern of the proximity sensor 20. There are three coupling modes, for example, a first mode to a third mode. The switching unit 21 sets the coupling mode and switches the coupling pattern based on a switching signal output by the control unit 10.

[0031] The first mode is a coupling mode in which the number of coupling electrodes is greater than that of the second mode, the area of ​​the coupling electrodes is smaller, and the sensitivity is higher than that of the second mode. The second mode is a coupling mode in which the number of coupling electrodes is greater than that of the third mode, the area of ​​the coupling electrodes is smaller, and the sensitivity is higher than that of the third mode.

[0032] The first mode is a mode with high spatial resolution but not high distance performance, for example, a combined mode used when the target object is at a short distance. The first mode has, for example, a spatial resolution of 8 and a distance performance of 1. The third mode is a mode with not high spatial resolution and not high distance performance, for example, a combined mode used when the target object is at a long distance. The third mode has, for example, a spatial resolution of 1 and a distance performance of 8.

[0033] The second mode is, for example, a mode with medium spatial resolution and distance performance, and is, for example, a combined mode used when the target object is at a medium distance. The second mode has, for example, a spatial resolution of 4 and a distance performance of 2. The combined electrode is formed by, for example, one of the first transmitting / receiving electrodes 41 to the eighth transmitting / receiving electrodes 48 or two or more of the first transmitting / receiving electrodes 41 to the eighth transmitting / receiving electrodes 48 that are connected together.

[0034] In this case, for example, the first mode may have one coupled electrode (1 ch) at each joint and a range (detectable distance) of 2 mm, the second mode may have one coupled electrode (1 ch) at each finger and a range of 15 mm, and the second mode may have one coupled electrode (1 ch) at all fingers and a range of 50 mm.In other cases, for example, if six transmitting and receiving electrodes are provided on the palm, the first mode may have six coupled electrodes (6 ch) at the palm, the second mode may have two to three coupled electrodes (2 to 3 ch) at the palm, and the third mode may have one coupled electrode (1 ch) at the palm or the entire hand.

[0035] The control unit 10 generates a switching instruction to switch the coupling mode so that the number of coupled electrodes decreases and the area of ​​the coupled electrodes increases, for example, during approach to the target object. Furthermore, the control unit 10 generates a switching instruction to switch the coupling mode so that the number of coupled electrodes increases and the area of ​​the coupled electrodes decreases, for example, when grasping or manipulating the target object.

[0036] Alternatively, when the target distance is smaller than a preset threshold, the control unit 10 generates a switching instruction to switch the coupling mode so that the number of coupled electrodes increases and the area of ​​the coupled electrodes decreases.When the target distance is larger than a preset threshold, the control unit 10 generates a switching instruction to switch the coupling mode so that the number of coupled electrodes decreases and the area of ​​the coupled electrodes increases.

[0037] 3 is a diagram showing an example of thresholds. Thresholds are set for each mode for the target distances of an approaching target object and a moving away target object. Examples of reference thresholds include an approach reference threshold TH1 used when the target object is approaching and a moving away reference threshold TH2 used when the target object is moving away.

[0038] For the first mode, a first approach threshold TH11 and a first separation threshold TH21 are set. For the second mode, a second approach threshold TH12 and a second separation threshold TH22 are set. For the third mode, a third approach threshold TH13 and a third separation threshold TH23 are set. The first approach threshold TH11, the second approach threshold TH12, and the third approach threshold TH13 are thresholds that are referenced when a target object is approaching, and the first separation threshold TH21, the second separation threshold TH22, and the third separation threshold TH23 are thresholds that are referenced when a target object is separating.

[0039] The first curve R1 represents the relationship between the proximity sensor value and the target distance when the combination mode is the first mode. The second curve R2 represents the relationship between the proximity sensor value and the target distance when the combination mode is the second mode. The third curve R3 represents the relationship between the proximity sensor value and the target distance when the combination mode is the third mode.

[0040] For example, when the target distance is sufficiently large, the proximity sensor 20 does not calculate the target distance, but calculates the target distance based on information acquired (measured), such as by calculation based on an image captured by a body device, for example, the camera 30. Subsequently, when the target object approaches and the target distance becomes smaller than the third approach threshold TH13, the proximity sensor 20, whose combined mode is set to the third mode, starts detecting the target object and calculating the target distance.

[0041] Subsequently, when the target object approaches further and the target distance becomes smaller than the second approach threshold TH12, the coupling mode is switched from the third mode to the second mode. Subsequently, when the target object approaches further and the target distance becomes smaller than the first approach threshold TH11, the coupling mode is switched from the second mode to the first mode.

[0042] Furthermore, if the target object moves away while the proximity sensor 20 is detecting the target object and calculating the target distance in the first combined mode, and the target distance becomes larger than the first separation threshold TH21, the combined mode is switched from the first mode to the second mode. Subsequently, if the target object approaches further and the target distance becomes larger than the second separation threshold TH22, the combined mode is switched from the second mode to the third mode.

[0043] Subsequently, when the target object approaches further and the target distance becomes greater than the third separation threshold TH23, the target distance becomes sufficiently large. At this time, detection of the target object by the proximity sensor 20 is terminated. Thereafter, the target object is detected, for example, by image processing an image captured by the camera 30, and the target distance is calculated based on the image captured by the camera 30.

[0044] The three coupling modes, the first mode to the third mode, will be described below in order. FIG. 4 is a diagram showing how the circuit in the proximity sensor 20 is connected in the first mode. In the first mode, the connections between the first transmitting / receiving electrode 41 to the eighth transmitting / receiving electrode 48 and the switching unit 21 via the first wiring 51 to the eighth wiring 58 are individually turned ON, and the connections between the transmitting / receiving electrodes and the wiring other than the ones that are turned ON are turned OFF. For example, when the connection between the first transmitting / receiving electrode 41 and the switching unit 21 via the first wiring 51 is individually turned ON, the connections between the second transmitting / receiving electrode 42 to the eighth transmitting / receiving electrode 48 and the switching unit 21 via the other second wiring 52 to the eighth wiring 58 are turned OFF.

[0045] In this case, the first coupling electrode M11 is generated by the first transmitting / receiving electrode 41. Similarly, when the second transmitting / receiving electrode 42 to the eighth transmitting / receiving electrode 48 are each independently connected to the switching section 21 by the second wiring 52 to the eighth wiring 58, the second transmitting / receiving electrode 42 to the eighth transmitting / receiving electrode 48 generate the second coupling electrode M12 to the eighth coupling electrode M18, respectively.

[0046] The first to eighth coupling electrodes M11 to M18 generate an electric field and detect capacitance corresponding to the generated electric field. The first to eighth coupling electrodes M11 to M18 generate a proximity sensor signal based on the detected capacitance. The first to eighth coupling electrodes M11 to M18 output the generated proximity sensor signal to the measurement unit 22 via the first to eighth wirings 51 to 58 and the switching unit 21.

[0047] 5 is a diagram showing an example of a measurement mode when the circuit of the proximity sensor 20 is connected in the first mode. When the circuit is connected in the first mode, the control unit 10 first turns on the connection between the first transmitting / receiving electrode 41 and the switching unit 21 via the first wiring 51 to generate a first coupling electrode M11. The first coupling electrode M11 generates an electric field and detects capacitance, generates a proximity sensor signal, and outputs it to the measurement unit 22.

[0048] Next, the control unit 10 turns off the connection between the first transmitting / receiving electrode 41 and the switching unit 21 to cancel the first coupling electrode M11, and turns on the connection between the second transmitting / receiving electrode 42 and the switching unit 21 via the second wiring 52 to generate the second coupling electrode M12. The generated second coupling electrode M12 generates an electric field and detects capacitance, and generates a proximity sensor signal based on the detected capacitance. The second coupling electrode M12 outputs the signal to the measurement unit 22.

[0049] Similarly, the third coupling electrode M13 is generated and the second coupling electrode M12 is eliminated, the fourth coupling electrode M14 is generated and the third coupling electrode M13 is eliminated, and the proximity sensor signal associated with these is output in sequence, and after the eighth coupling electrode M18 is generated and the seventh coupling electrode M17 is eliminated, the first coupling electrode M11 is generated again and the eighth coupling electrode M18 is eliminated, and a proximity sensor signal is output. Thereafter, the generation and elimination of the coupled electrodes are repeated in the same manner, and a proximity sensor signal is output.

[0050] Next, a second mode of circuit connection in the proximity sensor 20 will be described. Fig. 6 is a diagram showing the circuit connection in the second mode in the proximity sensor 20. In the second mode, two transmitting and receiving electrodes form a set, and connection to the switching unit 21 via two wires is turned ON, while connection between the transmitting and receiving electrodes and the switching unit 21 via the other wires is turned OFF. For example, the first transmitting and receiving electrode 41 and the second transmitting and receiving electrode 42 form a set, and connection to the switching unit 21 is turned ON via the first wire 51 and the second wire 52, while connection between the third transmitting and receiving electrode 43 to the eighth transmitting and receiving electrode 48 and the switching unit 21 via the other wires, the third wire 53 to the eighth wire 58, is turned OFF.

[0051] In this case, a first coupling electrode M21 is generated by the first transmitting / receiving electrode 41 and the second transmitting / receiving electrode 42. Similarly, when the third transmitting / receiving electrode 43 and the fourth transmitting / receiving electrode 44 are set and the connection with the switching unit 21 via the third wiring 53 and the fourth wiring 54 is turned ON, a second coupling electrode M22 is generated by the third transmitting / receiving electrode 43 and the fourth transmitting / receiving electrode 44.

[0052] Furthermore, when the fifth transmitting / receiving electrode 45 and the sixth transmitting / receiving electrode 46 are set together and the connection with the switching unit 21 via the fifth wiring 55 and the sixth wiring 56 is turned ON, a third coupling electrode M23 is generated by the fifth transmitting / receiving electrode 45 and the sixth transmitting / receiving electrode 46. When the seventh transmitting / receiving electrode 47 and the eighth transmitting / receiving electrode 48 are set together and the connection with the switching unit 21 via the seventh wiring 57 and the eighth wiring 58 is turned ON, a fourth coupling electrode M24 is generated by the seventh transmitting / receiving electrode 47 and the eighth transmitting / receiving electrode 48.

[0053] The first to fourth coupling electrodes M21 to M24 generate an electric field and detect capacitance corresponding to the generated electric field. The first to fourth coupling electrodes M21 to M24 generate a proximity sensor signal based on the detected capacitance. The first to fourth coupling electrodes M21 to M24 output the generated proximity sensor signal to the measurement unit 22 via the first to eighth wirings 51 to 58 and the switching unit 21.

[0054] 7 is a diagram showing an example of the measurement mode when the circuit of the proximity sensor 20 is connected in the second mode. When the control unit 10 connects the circuit in the second mode, it first sets the first transmitting and receiving electrode 41 and the second transmitting and receiving electrode 42 as a set, and turns on the connection with the switching unit 21 via the first wiring 51 and the second wiring 52 to generate the first coupling electrode M21. The first coupling electrode M21 generates an electric field and detects capacitance, generates a proximity sensor signal, and outputs it to the measurement unit 22.

[0055] Next, the first coupling electrode M21 is dissolved by turning OFF the connection between the first transmitting / receiving electrode 41 and the second transmitting / receiving electrode 42 and the switching unit 21, the third transmitting / receiving electrode 43 and the fourth transmitting / receiving electrode 44 are set, and the connection with the switching unit 21 via the third wiring 53 and the fourth wiring 54 is turned ON to generate the second coupling electrode M22. The generated second coupling electrode M22 generates an electric field and detects capacitance, and generates a proximity sensor signal based on the detected capacitance and outputs it to the measurement unit 22.

[0056] Similarly, the third coupling electrode M23 is generated and the second coupling electrode M22 is canceled, the fourth coupling electrode M24 is generated and the third coupling electrode M23 is canceled, and the proximity sensor signal associated with these is output in sequence. After the fourth coupling electrode M24 is generated and the third coupling electrode M23 is canceled, the first coupling electrode M21 is generated again and the fourth coupling electrode M24 is canceled, and the proximity sensor signal is output. Thereafter, the generation and cancellation of the coupled electrodes are repeated in the same manner, and the proximity sensor signal is output.

[0057] Next, a description will be given of a third mode of circuit connection in the proximity sensor 20. Fig. 8 is a diagram showing a third mode of circuit connection in the proximity sensor 20. In the third mode, all of the connections of the first transmitting and receiving electrodes 41 to the eighth transmitting and receiving electrodes 48 with the switching unit 21 via the first wiring 51 to the eighth wiring 58 are turned ON or OFF as a set.

[0058] In the third mode, the first transmitting / receiving electrode 41 to the eighth transmitting / receiving electrode 48 form a coupling electrode M31. The coupling electrode M31 generates an electric field and detects capacitance corresponding to the generated electric field. The coupling electrode M31 generates a proximity sensor signal based on the detected capacitance and outputs the generated proximity sensor signal to the measurement unit 22 via the first wiring 51 to the eighth wiring 58 and the switching unit 21.

[0059] 9 is a diagram showing an example of a measurement mode when the circuit of the proximity sensor 20 is connected in the third mode. When the circuit is connected in the third mode, the control unit 10 turns on the connections of the first wiring 51 to the eighth wiring 58 and the first transmitting / receiving electrode 41 to the eighth transmitting / receiving electrode 48 with the switching unit 21 to generate the coupling electrode M31. The coupling electrode M31 generates an electric field and detects capacitance, generates a proximity sensor signal, and outputs it to the measurement unit 22. Thereafter, the coupling electrode M31 sequentially generates an electric field, detects capacitance, and outputs a proximity sensor signal.

[0060] Next, the processing in the control unit 10 will be described. Figures 10 to 12 are flowcharts showing an example of the processing in the control unit 10. Figure 10 shows the flow when the control unit 10 starts detecting a target object. First, the control unit 10 acquires the target distance detected by an external device such as the camera 30 (step S101).

[0061] Next, the control unit 10 determines whether the acquired target distance is smaller than the third approach threshold TH13 (step S103). If the control unit 10 determines that the target distance is not smaller (greater) than the third approach threshold TH13, the control unit 10 returns the process to step S101. If the control unit 10 determines that the target distance is smaller than the third approach threshold TH13, the control unit 10 determines whether the acquired target distance is smaller than the second approach threshold TH12 (step S105).

[0062] If the control unit 10 determines that the target distance is greater than the second approach threshold TH12, it sets the coupling mode to the third mode (step S107). Then, the control unit 10 ends the process shown in Fig. 10. If the control unit 10 determines that the target distance is not greater (smaller) than the second approach threshold TH12, it determines whether the acquired target distance is smaller than the first approach threshold TH11 (step S109).

[0063] If it is determined that the target distance is smaller than the first approach threshold TH11, the control unit 10 sets the combination mode to the first mode (step S111) and ends the process shown in Fig. 10. If it is determined that the target distance is not smaller (greater) than the first approach threshold TH11, the control unit 10 sets the combination mode to the second mode (step S113) and ends the process shown in Fig. 10.

[0064] Next, the process performed by the control unit 10 after the start of detection of a target object will be described with reference to Fig. 11. When the control unit 10 starts detection of a target object, the control unit 10 determines whether the target object is approaching (step S201). If the control unit 10 determines that the target object is not approaching, the control unit 10 proceeds to the process shown in Fig. 12.

[0065] If it is determined that the target object is approaching, the control unit 10 determines whether the current combination mode is the third mode (step S203). If it is determined that the combination mode is the third mode, the control unit 10 acquires the target distance output by the measurement unit 22 and determines whether the target distance is smaller than the second approach threshold TH12 (step S205).

[0066] If the control unit 10 determines that the target distance is not smaller (greater) than the second approach threshold TH12, the control unit 10 maintains the combination mode in the third mode and terminates the process shown in Fig. 11. If the control unit 10 determines that the target distance is smaller than the second approach threshold TH12, the control unit 10 generates a switching signal including a switching instruction to switch the combination mode from the third mode to the second mode, and outputs the signal to the switching unit 21 (step S207). In this way, the control unit 10 terminates the process shown in Fig. 11.

[0067] If it is determined in step S203 that the combination mode is not the third mode, the control unit 10 determines whether the combination mode is the second mode (step S209).If it is determined that the combination mode is the second mode, the control unit 10 determines whether the target distance is smaller than a second approach threshold TH12 (step S211).

[0068] If the control unit 10 determines that the target distance is smaller than the second approach threshold TH12, it generates a switching signal including a switching instruction to switch the combined mode from the second mode to the first mode, and outputs the signal to the switching unit 21 (step S213). Then, the control unit 10 ends the process shown in Fig. 11. If the control unit 10 determines that the target distance is not smaller (greater) than the second approach threshold TH12, the control unit 10 maintains the combined mode in the second mode, and therefore ends the process shown in Fig. 11.

[0069] If it is determined in step S209 that the combination mode is not the second mode, the control unit 10 confirms that the combination mode is the first mode (step S215). Thereafter, the control unit 10 ends the process shown in Fig. 7. Next, the process of the control unit 10 when it is determined in step S201 that the target object is not approaching will be described with reference to Fig. 12.

[0070] If it is determined that the target object is not approaching, the control unit 10 confirms that the target object is moving away or is stationary (step S301). Subsequently, the control unit 10 determines whether the coupling mode is the first mode (step S303). If it is determined that the coupling mode is the first mode, the control unit 10 determines whether the target distance is smaller than a first separation threshold TH21 (step S305).

[0071] If the control unit 10 determines that the target distance is smaller than the first separation threshold TH21, it generates a switching signal including a switching instruction to switch the coupling mode from the first mode to the second mode, and outputs the signal to the switching unit 21 (step S307). Thereafter, the control unit 10 ends the processing shown in Fig. 12. If the control unit 10 determines that the target distance is not smaller (greater) than the first separation threshold TH21, the control unit 10 maintains the coupling mode in the first mode, and therefore ends the processing shown in Fig. 12.

[0072] If it is determined in step S303 that the combination mode is not the first mode, the control unit 10 determines whether the combination mode is the second mode (step S309).If it is determined that the combination mode is the second mode, the control unit 10 determines whether the target distance is smaller than a second separation threshold TH22 (step S311).

[0073] If the control unit 10 determines that the target distance is smaller than the second separation threshold TH22, it generates a switching signal including a switching instruction to switch the coupling mode from the second mode to the third mode and outputs the signal to the switching unit 21 (step S313). Thereafter, the control unit 10 ends the processing shown in Fig. 12. If the control unit 10 determines that the target distance is not smaller (greater) than the second separation threshold TH22, the control unit 10 maintains the coupling mode in the second mode and therefore ends the processing shown in Fig. 12.

[0074] If it is determined in step S309 that the combination mode is not the second mode, the control unit 10 confirms that the combination mode is the third mode (step S315). Subsequently, the control unit 10 determines whether the target distance is smaller than a third separation threshold TH23 (step S317).

[0075] If the control unit 10 determines that the target distance is smaller than the third separation threshold TH23, it ends the detection of the target object by the proximity sensor 20 and the calculation of the target distance, and starts the detection of the target object and the calculation of the target distance based on the information measured by the external device (step S319). Thereafter, the control unit 10 ends the process shown in Fig. 12. If the control unit 10 determines that the target distance is not smaller (greater) than the third separation threshold TH23, it ends the process shown in Fig. 12 to maintain the coupling mode in the third mode.

[0076] The object detection system 1 of the first embodiment adjusts the sensitivity of the proximity sensor 20 by switching the connection of the multiple transmitting and receiving electrodes. As a result, the target object is detected with appropriate spatial resolution and distance performance using an appropriate coupling mode according to the target distance. As a result, the target object can be detected efficiently.

[0077] Second Embodiment Next, a second embodiment will be described. FIG. 13 is a diagram showing an example of the configuration of an object detection system 2 according to the second embodiment. The object detection system 2 according to the second embodiment is a so-called mutual capacitance type object detection system. The object detection system 2 according to the second embodiment includes, for example, a control unit 10 and a proximity sensor 70. The proximity sensor 70 includes a switching unit 21, a measuring unit 22, first transmitting and receiving electrodes 61 to eighth transmitting and receiving electrodes 68, and first wirings 71 to eighth wirings 78. Of these, the control unit 10, the switching unit 21, and the measuring unit 22 are the same as those in the object detection system 1 according to the first embodiment.

[0078] The first transmitting / receiving electrode 61 to the eighth transmitting / receiving electrode 68 function as either transmitting electrodes or receiving electrodes. The first transmitting / receiving electrode 61 to the eighth transmitting / receiving electrode 68 may be electrodes having both the function of generating an electric field and the function of detecting capacitance, or may be electrodes having either the function of generating an electric field or the function of detecting capacitance. The first wiring 71 to the eighth wiring 78 connect the first transmitting / receiving electrode 61 to the eighth transmitting / receiving electrode 68 to the switching unit 21, respectively. The first wiring 71 to the eighth wiring 78 form a circuit.

[0079] As in the first embodiment, the switching unit 21 in the proximity sensor 70 switches the coupling pattern by setting a coupling mode according to a switching instruction. For example, based on a switching instruction included in a switching signal output from the control unit 10, the switching unit 21 sets eight transmitting and receiving electrodes as transmitting electrodes and selects the transmitting and receiving electrodes that are not set as transmitting electrodes as receiving electrodes, thereby dividing the transmitting and receiving electrodes into transmitting electrodes and receiving electrodes. The transmitting electrodes generate an electric field, and the receiving electrodes absorb electric field lines and detect capacitance. The switching unit 21 selects the transmitting and receiving electrodes as transmitting electrodes or receiving electrodes, and prevents the transmitting and receiving electrodes from simultaneously transmitting and receiving.

[0080] 14 is a diagram showing an example of how the transmitting and receiving electrodes 60 are used. The first transmitting and receiving electrode 61 to the eighth transmitting and receiving electrode 68 are provided, for example, as transmitting and receiving electrodes 60, 60. The transmitting and receiving electrodes 60, 60 are provided, for example, on one side of a surface panel P of a robot hand, with one electrode generating an electric field indicated by electric force lines E and the other electrode absorbing the electric force lines. As a result, a pseudo-capacitor is generated between the transmitting and receiving electrodes 60, 60.

[0081] For example, when a target object, such as a human hand H, approaches the front panel P, a capacitor is also generated between the electric field and the hand, reducing the capacitance between the transmitting and receiving electrodes 60, 60. The other transmitting and receiving electrode 60 detects the reduced capacitance, generates a proximity sensor signal based on the detected capacitance, and outputs it to the measurement unit 22. The measurement unit 22 detects the proximity of the target object (hand H) based on the reduction in capacitance.

[0082] The control unit 10 controls the sensitivity of the proximity sensor 70 by specifying a coupling mode and causing the switching unit 21 to switch the coupling pattern of the proximity sensor 20. As the coupling mode, there are, for example, three modes, a first mode to a third mode, similar to the first embodiment. The switching unit 21 sets the coupling mode and switches the coupling pattern based on a switching signal output by the control unit 10. Other points are the same as those in the first embodiment.

[0083] The first mode is a mode with high spatial resolution but not high distance performance, and is, for example, a coupling mode used when the target object is at a short distance. The first coupling electrode M51 in the first mode includes two transmitting / receiving electrodes (one pair of transmitting and receiving electrodes). The first mode has, for example, a spatial resolution of 4 and a distance performance of 2. The third mode is a mode with not high spatial resolution and not high distance performance, and is, for example, a coupling mode used when the target object is at a long distance. The third coupling electrode M13 in the third mode includes eight transmitting / receiving electrodes (four pairs of transmitting and receiving electrodes). The third mode has, for example, a spatial resolution of 1 and a distance performance of 8.

[0084] The second mode is, for example, a mode with medium spatial resolution and distance performance, and is a coupling mode used when, for example, the target object is at a medium distance. The second coupling electrode M12 in the second mode includes four transmitting / receiving electrodes (two pairs of transmitting and receiving electrodes). The second mode has, for example, a spatial resolution of 2 and a distance performance of 4. The coupling electrode is formed, for example, by one of the first transmitting / receiving electrodes 41 to the eighth transmitting / receiving electrodes 48 or two or more of the first transmitting / receiving electrodes 41 to the eighth transmitting / receiving electrodes 48 that are connected together.

[0085] The three coupling modes, first to third modes, of the second embodiment will be described in order below. Fig. 15 is a diagram showing how the circuit in the proximity sensor 70 is connected in the first mode. In the proximity sensor 70, for example, the first transmitting / receiving electrode 61 and the second transmitting / receiving electrode 62 form a first channel CH1. Similarly, the third transmitting / receiving electrode 63 and the fourth transmitting / receiving electrode 64 form a second channel CH2, the fifth transmitting / receiving electrode 65 and the sixth transmitting / receiving electrode 66 form a third channel CH3, and the seventh transmitting / receiving electrode 67 and the eighth transmitting / receiving electrode 68 form a fourth channel CH4.

[0086] In the first mode, the connection between the first channel CH1 and the switching unit 21 via the first transmitting / receiving electrode 61 and the second transmitting / receiving electrode 62 is turned ON individually for each channel, and the connection via wiring between channels other than the channel whose connection is turned ON and the switching unit 21 is turned OFF. For example, when the connection between the first channel CH1 and the switching unit 21 is turned ON individually, the connections between the other channels, the second channel CH2 to the fourth channel CH4, and the switching unit 21 are each turned OFF.

[0087] In this case, the first channel CH1 generates a first coupling electrode M41. Similarly, when the second channel CH2 to the fourth channel CH4 are connected to the switching unit 21 independently, the second channel CH2 to the fourth channel CH4 generate a second coupling electrode M42 to a fourth coupling electrode M44, respectively.

[0088] The first to fourth coupling electrodes M41 to M44 generate an electric field and detect capacitance corresponding to the generated electric field. The first to fourth coupling electrodes M41 to M44 generate a proximity sensor signal based on the detected capacitance. The first to fourth coupling electrodes M41 to M44 output the generated proximity sensor signal to the measurement unit 22.

[0089] 16 is a diagram showing an example of the measurement mode when the circuit of the proximity sensor 70 is connected in the first mode. When the circuit is connected in the first mode, the control unit 10 first connects the first channel CH1 to the switching unit 21 to generate a first coupling electrode M41. The first coupling electrode M41 generates an electric field and detects capacitance, generates a proximity sensor signal, and outputs it to the measurement unit 22.

[0090] Next, the connection between the first channel CH1 and the switching unit 21 is turned OFF to cancel the first coupling electrode M41, and the connection between the second channel CH2 and the switching unit 21 is turned ON to generate the second coupling electrode M42. The generated second coupling electrode M42 generates an electric field and detects capacitance, and generates a proximity sensor signal based on the detected capacitance and outputs it to the measurement unit 22.

[0091] Similarly, the third coupling electrode M43 is generated and the second coupling electrode M42 is canceled, the fourth coupling electrode M44 is generated and the third coupling electrode M43 is canceled, and the proximity sensor signal is output accordingly. After that, the first coupling electrode M41 is generated again and the fourth coupling electrode M44 is canceled, and the proximity sensor signal is output. Thereafter, the generation and cancellation of the coupled electrodes are repeated in the same manner, and the proximity sensor signal is output.

[0092] Next, a second mode of circuit connection in the proximity sensor 70 will be described. Fig. 17 is a diagram showing the circuit connection in the second mode in the proximity sensor 70. In the second mode, two channels form a set and are connected to the switching unit 21, and the other channels are connected to the switching unit 21, but not connected to the switching unit 21. For example, the first channel CH1 and the second channel CH2 form a set and are connected to the switching unit 21, and the other channels, the third channel CH3 and the fourth channel CH4, are connected to the switching unit 21, but not connected to the switching unit 21.

[0093] In this case, the first channel CH1 and the second channel CH2 form a first coupling electrode M51. Similarly, when the third channel CH3 and the fourth channel CH4 are set and the connection with the switching unit 21 is turned ON, the third channel CH3 and the fourth channel CH4 form a second coupling electrode M52.

[0094] The first coupling electrode M51 and the second coupling electrode M52 generate an electric field and detect a capacitance corresponding to the generated electric field. The first coupling electrode M51 and the second coupling electrode M52 generate a proximity sensor signal based on the detected capacitance. The first coupling electrode M51 and the second coupling electrode M52 output the generated proximity sensor signal to the measurement unit 22 via the switching unit 21.

[0095] 18 is a diagram showing an example of the measurement mode when the circuit of the proximity sensor 70 is connected in the second mode. When the circuit is connected in the second mode, the control unit 10 first sets the first channel CH1 and the second channel CH2 as a set, turns on the connection with the switching unit 21, and generates the first coupling electrode M51. The first coupling electrode M51 generates an electric field and detects capacitance, generates a proximity sensor signal, and outputs it to the measurement unit 22.

[0096] Next, the first channel CH1 and the second channel CH2 are disconnected from the switching unit 21 to cancel the first coupling electrode M51, the third channel CH3 and the fourth channel CH4 are set, and the connection with the switching unit 21 is turned on to generate the second coupling electrode M52. The generated second coupling electrode M52 generates an electric field and detects capacitance, and generates a proximity sensor signal based on the detected capacitance and outputs it to the measurement unit 22.

[0097] Similarly, the generation of the first coupling electrode M51 and the cancellation of the second coupling electrode M52, the generation of the second coupling electrode M52 and the cancellation of the first coupling electrode M51, and the output of the proximity sensor signal associated therewith are sequentially executed. Thereafter, the generation and cancellation of the first coupling electrode M51 and the second coupling electrode M52 are repeated in the same manner to output the proximity sensor signal.

[0098] Next, we will explain the third mode of circuit connection in the proximity sensor 70. Fig. 19 is a diagram showing the third mode of circuit connection in the proximity sensor 70. In the third mode, all of the connections to the switching unit 21 of the first channel CH1 to the fourth channel CH4 are turned ON or OFF as a set.

[0099] In the third mode, the first channel CH1 to the fourth channel CH4 form a coupling electrode M61. The coupling electrode M61 generates an electric field and detects capacitance corresponding to the generated electric field. The coupling electrode M61 generates a proximity sensor signal based on the detected capacitance and outputs the generated proximity sensor signal to the measurement unit 22 via the switching unit 21.

[0100] 20 is a diagram showing an example of the measurement mode when the circuit of the proximity sensor 70 is connected in the third mode. When the circuit is connected in the third mode, the control unit 10 turns on the connections of the first wiring 51 to the eighth wiring 58 and the first transmitting / receiving electrode 41 to the eighth transmitting / receiving electrode 48 with the switching unit 21 to generate the coupling electrode M31. The coupling electrode M31 generates an electric field and detects capacitance, generates a proximity sensor signal, and outputs it to the measurement unit 22. Thereafter, the coupling electrode M31 sequentially generates an electric field, detects capacitance, and outputs a proximity sensor signal.

[0101] The object detection system 2 of the second embodiment has the same effects as the object detection system 1 of the first embodiment. Furthermore, the object detection system 2 of the second embodiment detects a target object using a mutual induction proximity sensor 70. Therefore, for example, even if the target object is spread across multiple positions, the position of the target object can be set with high accuracy.

[0102] In each of the above embodiments, the control unit 10 switches the coupling mode based on the target distance, but the control unit 10 may switch the coupling mode based on other criteria. For example, the control unit 10 may switch between the second mode and the third mode based on whether the fingertips of the robot hand are hidden by the target object in the image captured by the camera 30, or may switch between the first mode and the second mode based on whether the robot hand has come into contact with the target object.

[0103] The above-described embodiment can be expressed as follows: An apparatus comprising: a storage medium storing computer-readable instructions; and a processor connected to the storage medium, including a plurality of electrodes, for controlling sensitivity of a proximity sensor that detects a target object based on a change in capacitance, wherein the processor executes the computer-readable instructions to: generate a switching instruction regarding how to connect a circuit that connects the plurality of electrodes, and output the instruction to a switching unit; change a coupled electrode formed by one or a plurality of connected electrodes and an area of ​​the coupled electrode to adjust the sensitivity of the proximity sensor; and detect the target object using the proximity sensor.

[0104] The above describes the form for carrying out the present invention using an embodiment, but the present invention is not limited to such an embodiment, and various modifications and substitutions can be made within the scope that does not deviate from the gist of the present invention.

[0105] 1, 2 Object detection system 10 Control unit 20 Proximity sensor 21 Switching unit 22 Measurement unit 30 Camera 40 (41 to 48), 60 (61 to 68) Transmitting and receiving electrodes 51 to 58, 71 to 78 Wiring 70 Proximity sensor CH1 to CH4 First channel to fourth channel E Electric line of force H Hand M11 to M18, M21 to M24, M31, M41 to M44, M51, M52, M61 Coupling electrode R1 First curve R2 Second curve R3 Third curve TH1 Approach reference threshold TH2 Separation reference threshold TH11 First approach threshold TH12 Second approach threshold TH13 Third approach threshold TH21 First separation threshold TH22 Second separation threshold TH23 Third separation threshold

Claims

1. An object detection system that controls the sensitivity of a proximity sensor that has multiple electrodes and detects a target object based on changes in capacitance, further comprising: a circuit that connects the multiple electrodes; a switching unit that switches how the circuits that connect the multiple electrodes are connected; and a control unit that generates a switching instruction regarding how the circuits are connected and outputs it to the switching unit.

2. The object detection system according to claim 1, wherein the control unit generates the switching instruction based on the detection result of the proximity sensor.

3. The object detection system of claim 1, wherein the control unit generates the switching instruction to switch the way the circuit is connected so that the number of coupled electrodes formed by one or more connected electrodes increases and the area of ​​the coupled electrodes decreases when the distance to the target object is smaller than a predetermined threshold, and generates the switching instruction to switch the way the circuit is connected so that the number of coupled electrodes formed by one or more connected electrodes decreases and the area of ​​the coupled electrodes increases when the distance to the target object is greater than a predetermined threshold.

4. The object detection system of claim 1 or 2, wherein the electrodes are mounted on a robot that manipulates the target object, and the control unit generates the switching instruction to switch the way the circuit is connected so that, while approaching the target object, the number of coupled electrodes formed by one or more connected electrodes decreases and the area of ​​the coupled electrodes increases, and when grasping or manipulating the target object, the control unit generates the switching instruction to switch the way the circuit is connected so that the number of coupled electrodes formed by one or more connected electrodes increases and the area of ​​the coupled electrodes decreases.

5. An object detection method comprising: a control unit that controls the sensitivity of a proximity sensor that has a plurality of electrodes and detects a target object based on changes in capacitance; generating a switching instruction regarding how to connect a circuit that connects the plurality of electrodes and outputting it to a switching unit; changing a coupled electrode formed by one or a plurality of connected electrodes and the area of ​​the coupled electrode to control the sensitivity of the proximity sensor; and detecting the target object using the proximity sensor.

6. A program that causes a control unit that controls the sensitivity of a proximity sensor that has multiple electrodes and detects a target object based on changes in capacitance to generate switching instructions regarding how to connect the circuits that connect the multiple electrodes and output them to the switching unit, change the combined electrode formed by one or multiple connected electrodes and the area of ​​the combined electrode to control the sensitivity of the proximity sensor, and detect the target object using the proximity sensor.

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