Robot control device

Abstract

The present invention provides a robot control device that can suppress false detections in non-contact sensors. [Solution] The robot control device is a robot control device for a robot equipped with a plurality of non-contact sensors 2e, 2b, and comprises: an identification unit that identifies the position of each non-contact sensor 2e, 2b in accordance with the posture of the robot; and a determination unit that identifies one of the plurality of non-contact sensors 2e, 2b as a target sensor and determines, based on the identified position, whether a non-contact sensor 2b other than the target sensor is interfering with the detection range 37e of the target sensor which has been set in advance.

Description

Technical Field

[0001] The present invention relates to a robot control device in a robot provided with a plurality of non-contact sensors.

Background Art

[0002] There are cases where a human and a robot cooperate to perform work on a workpiece. A robot used in such a case is called a collaborative robot. In a collaborative robot, a non-contact sensor for detecting an object such as a nearby person may be mounted.

[0003] For example, in Patent Document 1, it is described that a capacitive proximity sensor is provided on the arm of a robot to detect an object around the robot.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, a robot can take various poses in order to perform operations. Therefore, there is a possibility of interference between the non-contact sensors provided on the robot. When interference occurs, there is a possibility of false detection in the non-contact sensor.

[0006] In view of the above problems, an object of the present invention is to provide a robot control device capable of suppressing false detection in a non-contact sensor.

Means for Solving the Problems

[0007] To solve the above problems, the robot control device according to the present invention is a robot control device for a robot equipped with a plurality of non-contact sensors, comprising: a specification unit that specifies the position of each of the non-contact sensors in accordance with the posture of the robot; and a determination unit that specifies one of the plurality of non-contact sensors as a target sensor and determines, based on the specified position of each of the non-contact sensors, whether a non-contact sensor other than the target sensor is interfering with the detection range of the target sensor which has been set in advance.

[0008] Furthermore, in the robot control device, the determination unit determines that interference has occurred if a non-contact sensor different from the target sensor is located within the detection range of the target sensor.

[0009] Furthermore, in the robot control device, the detection range of the target sensor is a range that has been set in advance as a three-dimensional region for the target sensor.

[0010] Furthermore, in the robot control device, the determination unit determines that interference has occurred when the boundary surface of the detection range of the target sensor intersects with a non-contact sensor different from the target sensor, or when the entire non-contact sensor different from the target sensor is located inside the detection range of the target sensor.

[0011] Furthermore, the robot control device further includes a sensor control unit that, when the determination unit determines that interference has occurred, controls the non-contact sensors that are interfering with each other to avoid the interference.

[0012] Furthermore, in the robot control device, the sensor control unit performs at least one of the following controls on the non-contact sensors that interfere with each other: a control to disable object detection, a control to change the detection range, and a control to change the detection direction. [Effects of the Invention]

[0013] According to the robot control device of the present invention, false detection in the non-contact sensor can be suppressed.

Brief Description of Drawings

[0014] [Figure 1] FIG. 8 is a schematic diagram showing an example of the overall configuration of a robot system according to an embodiment of the present invention. [Figure 2] FIG. 11 is a diagram showing an example of various functions in the control device of FIG. 1. [Figure 3] FIG. 14 is a diagram showing an example of position identification of a non-contact sensor in the position identification unit of FIG. 2. [Figure 4] FIG. 17 is a diagram showing an example of the positional relationship among a plurality of non-contact sensors in FIG. 1. [Figure 5] FIG. 20 is a diagram showing another example of the positional relationship among a plurality of non-contact sensors in FIG. 1. [Figure 6] FIG. 23 is a diagram showing an example of avoidance control in the sensor control unit of FIG. 2. [Figure 7] FIG. 26 is a flowchart showing an example of the flow of interference determination processing in the control device of FIG. 1.

Embodiments for Carrying Out the Invention

[0015] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. For ease of understanding of the description, the same reference numerals are given to the same components in each drawing as much as possible, and duplicate descriptions are omitted as appropriate.

[0016] ===Embodiment=== <Overall Configuration> FIG. 42 is a diagram schematically showing an example of the overall configuration of a robot system 10 including a control device 3 as a robot control device according to an embodiment of the present invention.

[0017] The robot system 10 is an industrial robot that performs processes such as machining and conveyance on a workpiece. Further, the robot system 10 is a collaborative robot that works sharing the same space as a person, for example.

[0018] As shown in FIG. 1, the robot system 10 mainly includes a robot 1, a non-contact sensor 2, and a control device 3.

[0019] The robot 1 is an articulated robot and has a plurality of arms and a plurality of joints. Specifically, the robot 1 includes a base 7, a first arm A1, a second arm A2, a third arm A3, and a fourth arm A4. Note that the number of arms provided is not limited. The base 7 is the base of the robot 1. The base 7 is fixed to, for example, the floor surface or the wall surface and supports the entire robot 1. The first arm A1 is connected to the base 7 via a rotation axis. And the first arm A1 rotates around the rotation axis with respect to the base 7 by a motor (not shown). The second arm A2, the third arm A3, and the fourth arm A4 rotate around the rotation axis by respective motors (not shown) in the same manner as the first arm A1. A tool or the like is provided at the tip of the fourth arm A4. In this way, the arms are connected to other arms or the like with the rotation axis as a joint and are operable. By the movement of each joint, the robot 1 performs a predetermined operation.

[0020] The non-contact sensor 2 is a sensor that detects an object such as a person without contact. In the present embodiment, the "object" is a broad concept including a human and an object such as a workpiece. For example, the non-contact sensor 2 detects the proximity of an object. Note that the non-contact sensor 2 may detect the displacement of an object. In the present embodiment, a case where the proximity of an object is detected by the non-contact sensor 2 is taken as an example.

[0021] The non-contact sensor 2 is, for example, a capacitance-type sensor. Note that the non-contact sensor 2 is not limited to the capacitance-type sensor as long as it can detect an object without contact. For example, the non-contact sensor 2 may apply a sensor of a method such as infrared rays, ultrasonic waves, millimeter waves, or LiDAR. In the present embodiment, a case where the non-contact sensor 2 is a capacitance-type sensor is described as an example.

[0022] Multiple non-contact sensors 2 are provided on the robot 1. As shown in Figure 1, the robot 1 is equipped with, for example, non-contact sensors 2a, 2b, 2c, 2d, 2e, and 2f as non-contact sensors 2. Note that the installation locations and number of non-contact sensors 2 on the robot 1 shown in Figure 1 are just examples, and the installation locations and number of non-contact sensors 2 are not limited to the specific example shown in Figure 1.

[0023] The non-contact sensor 2 is constructed using a detection electrode. The detection electrode is, for example, flat. Alternatively, the detection electrode is, for example, rectangular. The shape of the detection electrode may be designed to match the outer shape of the arm, for example, and is not limited to that shape. The non-contact sensor 2 generates an electric field from the detection electrode in a predetermined direction. Specifically, the non-contact sensor 2 generates an electric field on the side opposite to the main body of the robot 1 to which it is attached. That is, the non-contact sensor 2 generates an electric field around the robot 1. The detection electrode of the non-contact sensor 2 then forms a capacitance with a nearby object. The capacitance changes depending on the distance between the detection electrode and the object. The non-contact sensor 2 outputs a sensor value corresponding to the capacitance formed between the detection electrode and the object. The non-contact sensor 2 amplifies the voltage corresponding to the capacitance generated at the detection electrode using an amplifier or the like, and outputs it as a sensor value. The specific circuit configuration of the non-contact sensor 2 is not limited. Furthermore, a known shield electrode or active shield electrode may be provided on the opposite side of the direction in which the electric field is generated (towards the main body of the robot 1) from the detection electrode.

[0024] In this way, the non-contact sensor 2 outputs a sensor value corresponding to the capacitance (i.e., distance) formed between it and the object.

[0025] Control device 3 is a robot control device. In other words, control device 3 is an information processing device that controls the movement of robot 1. Control device 3 is configured with, for example, a CPU, memory, communication device, and storage device, and performs various functions by executing a predetermined program.

[0026] <Functional configuration> Figure 2 shows an example of the various functions of the control device 3. The control device 3 comprises a control unit 21, a identification unit 22, a determination unit 23, and a sensor control unit 24.

[0027] The control unit 21 controls the movement of the robot 1. Specifically, the control unit 21 controls the movement of each arm of the robot 1 to cause the robot 1 to perform a predetermined action. In other words, the control unit 21 controls the rotation of each pivot axis that constitutes each joint of the robot 1.

[0028] Furthermore, the control unit 21 uses the sensor value, which is the output of the non-contact sensor 2, to stop the movement of the robot 1. Specifically, the control unit 21 compares the sensor value with a threshold value to determine whether or not an object is in close proximity to the robot 1. If the control unit 21 determines that an object is in close proximity to the robot 1, it stops the movement of the robot 1. For example, if the sensor value increases in response to the proximity of an object, the control unit 21 determines that an object is in close proximity when the sensor value exceeds the threshold value. For example, the control unit 21 stops the movement of the robot 1 even if it is in the middle of a predetermined movement. Note that the control unit 21 is not limited to stopping the movement of the robot 1, but may also slow down the movement of the robot 1.

[0029] The identification unit 22 identifies the position (coordinates) of each non-contact sensor 2 corresponding to the posture of the robot 1. For this purpose, the identification unit 22 includes a posture identification unit 27 and a position identification unit 28.

[0030] The posture determination unit 27 determines the posture of the robot 1. Specifically, the posture determination unit 27 obtains the angles of the rotation axes that constitute the joints of the robot 1. For example, the posture determination unit 27 obtains the angle (joint angle) at the rotation axis from an encoder provided on the rotation axis. Then, the posture determination unit 27 calculates the posture of the robot 1 based on the angles of each rotation axis. The posture of the robot 1 is indicated, for example, by the position and direction of the rotation center of each rotation axis that constitutes the robot 1. The posture determination unit 27 calculates the posture of the robot 1 from the angles of each rotation axis using link parameters. Link parameters are information that associates the angle of each rotation axis with the relative position and direction of each rotation axis. As a result, the posture determination unit 27 calculates the position and direction of the rotation center of each rotation axis from the angles of each rotation axis and determines the posture of the robot 1. The posture of the robot 1 is determined, for example, with respect to the base 7, which is a fixed position.

[0031] The positioning unit 28 determines the position (coordinates) of each non-contact sensor 2 installed on the robot 1, corresponding to the posture of the robot 1. Specifically, the positioning unit 28 determines the position of each non-contact sensor 2 using the position and direction of the rotation center of each rotation axis determined by the posture determining unit 27.

[0032] Figure 3 shows an example of positioning of the non-contact sensor 2. The positioning unit 28 identifies the position of the sensor surface 30 of each non-contact sensor 2. The sensor surface 30 is the surface of the detection electrode of the non-contact sensor 2. Figure 3 shows an example of when the positioning unit 28 identifies the position of the sensor surface 30e, which is the sensor surface 30 of the non-contact sensor 2e. The non-contact sensor 2e is provided on the fourth arm A4. Therefore, the position of the non-contact sensor 2e is identified with reference to the rotation axis corresponding to the fourth arm A4. Figure 3 shows an example of the rotation center of the rotation axis corresponding to the fourth arm A4 as rotation center C1, and an example of the direction of rotation center C1 as direction D1. The relative positional relationship between the rotation center C1 and the non-contact sensor 2e does not change with respect to the posture of the robot 1. Therefore, the positioning unit 28 identifies the position of the non-contact sensor 2e using sensor position parameters that indicate the relative positional relationship between the rotation center C1 and the non-contact sensor 2e. Specifically, the positioning unit 28 determines the position of the sensor surface 30e, which is the sensor surface 30, with respect to the rotation center C1. That is, the positioning unit 28 determines the position of the non-contact sensor 2e as a three-dimensional offset position relative to the rotation center C1 and as the size of the sensor surface 30e. For example, the positioning unit 28 determines the positions of the four corners (corners 31e, 32e, 33e, and 34e) of the sensor surface 30e of the non-contact sensor 2e with respect to the rotation center C1. This ensures that even if the robot 1 changes its posture, the position of the non-contact sensor 2e corresponding to that posture is determined. Furthermore, by determining the position relative to the rotation center C1, the direction of object detection by the sensor surface 30e of the non-contact sensor 2e (for example, the direction of electric field generation) is determined.

[0033] In this way, the positioning unit 28 determines the position of the sensor surface 30e of the non-contact sensor 2e in accordance with the posture of the robot 1. Similarly, the positioning unit 28 determines the position of the sensor surface 30 of the non-contact sensors 2 other than the non-contact sensor 2e in accordance with the posture of the robot 1.

[0034] Returning to Figure 2, the determination unit 23 determines the interference state between the multiple non-contact sensors 2 based on the position of each non-contact sensor 2 identified by the position identification unit 28. That is, the determination unit 23 determines the interference state based on the position of the sensor surface 30 of each non-contact sensor 2. An interference state is a state in which at least a part of another non-contact sensor 2 is within the detection range 37 of one non-contact sensor 2. The detection range 37 is the range in which an object can be detected by the non-contact sensor 2, and is preset for each non-contact sensor 2. Specifically, the detection range 37 is preset as a three-dimensional region for the non-contact sensor 2. In this embodiment, the detection range 37 is a rectangular parallelepiped region extending from the sensor surface 30 of the non-contact sensor 2.

[0035] The determination unit 23 designates one of the multiple non-contact sensors 2 as the "target sensor." It then determines whether the target sensor and a different non-contact sensor 2 are interfering with each other. Specifically, the determination unit 23 determines whether a different non-contact sensor 2 is located within the detection range 37 of the target sensor. In other words, the determination unit 23 determines whether the sensor surface 30 of a different non-contact sensor 2 is located within the detection range 37 of a rectangular parallelepiped extending from the sensor surface 30 of the target sensor.

[0036] Figure 4 shows an example of the positional relationship between a target sensor and a non-contact sensor 2 that is different from the target sensor. In Figure 4, the non-contact sensor 2e is shown as the target sensor. Also in Figure 4, the non-contact sensor 2b is shown as a non-contact sensor 2 that is different from the target sensor. That is, Figure 4 shows the positional relationship between the sensor surface 30e of the non-contact sensor 2e whose position has been determined by the position determination unit 28 and the sensor surface 30b of the non-contact sensor 2b. Then, a rectangular detection range 37e is set in a predetermined direction with respect to the sensor surface 30e of the non-contact sensor 2e as the target sensor. That is, the detection range 37e is a rectangular parallelepiped whose vertices are the four corners that make up the sensor surface 30e and the four corners 42e, 43e, 44e, and 45e of the boundary surface 41e which is a predetermined detection distance from the sensor surface 30e. Furthermore, the side surface between the sensor surface 30e and the interface surface 41e consists of four surfaces: interface surface 46e, interface surface 47e, interface surface 48e, and interface surface 49e. In addition, the sensor surface 30b of the non-contact sensor 2b has four edges: edge 51b, edge 52b, edge 53b, and edge 54b.

[0037] The determination unit 23 determines, based on the first determination, the second determination, and the third determination, whether or not the target sensor and a non-contact sensor 2 different from the target sensor are interfering with each other.

[0038] The determination unit 23 first performs a first determination. Specifically, the determination unit 23 sets a plane on which the sensor surface 30b of a non-contact sensor 2b, which is a non-contact sensor 2 different from the target sensor, extends. The determination unit 23 designates one direction perpendicular to the plane as the first direction and the other direction perpendicular to the plane as the second direction. The determination unit 23 then determines whether the entire region of the rectangular parallelepiped constituting the detection range 37e is located on the first direction side with respect to the plane. Specifically, the determination unit 23 determines whether all eight corners (corners 31e to 34e, and corners 42e to 45e) constituting the detection range 37e are located on the first direction side with respect to the plane. The determination unit 23 then determines that no interference has occurred if all eight corners constituting the detection range 37e are located on the first direction side with respect to the plane. Furthermore, the determination unit 23 determines whether all eight corners (corners 31e to 34e, and corners 42e to 45e) that constitute the detection range 37e are located on the second direction side with respect to the plane. The determination unit 23 determines that no interference has occurred if all eight corners that constitute the detection range 37e are located on the second direction side with respect to the plane. The determination unit 23 performs a second determination if all eight corners that constitute the detection range 37e are not located on the first or second direction side with respect to the plane. For example, in the case of Figure 4, all eight corners that constitute the detection range 37e are not located on the first or second direction side with respect to the plane to which the sensor surface 30b extends, so the second determination is performed.

[0039] Next, the determination unit 23 performs a second determination. Specifically, the determination unit 23 determines whether the boundary surface of the detection range 37e of the target sensor, the non-contact sensor 2e, intersects with the non-contact sensor 2b, which is a different non-contact sensor 2 from the target sensor. The boundary surface consists of six surfaces corresponding to the detection range 37e: the sensor surface 30e, boundary surface 41e, boundary surface 46e, boundary surface 47e, boundary surface 48e, and boundary surface 49e. Note that the boundary surface may consist of five surfaces excluding the sensor surface 30e. The determination unit 23 then determines whether each of the boundary surfaces intersects with the sensor surface 30b of the non-contact sensor 2b. Specifically, the determination unit 23 determines whether an intersection occurs between each of the boundary surfaces and each edge (edge ​​51b, edge 52b, edge 53b, edge 54b) of the sensor surface 30b of the non-contact sensor 2b. The determination unit 23 then determines that interference has occurred if there is any intersection between each of the boundary surfaces and each of the edges of the sensor surface 30b of the non-contact sensor 2b. In this case, it means that a part (but not the whole) of the non-contact sensor 2b is within the detection range 37e of the non-contact sensor 2e, and interference has occurred. The determination unit 23 also performs a third determination if there is no intersection between each of the boundary surfaces and each of the edges of the sensor surface 30b of the non-contact sensor 2b. The determination unit 23 may also determine that no interference has occurred if there is no intersection between the boundary surface and the edge of the sensor surface 30b. For example, in the case of Figure 4, the boundary surface of the detection range 37e of the non-contact sensor 2e and the non-contact sensor 2b intersect, so it is determined that interference has occurred.

[0040] The determination unit 23 then performs a third determination. Specifically, the determination unit 23 determines whether the entire non-contact sensor 2b, which is a different non-contact sensor 2 from the target sensor, is located inside the detection range 37e of the target non-contact sensor 2e. That is, the determination unit 23 determines whether the entire sensor surface 30b of the non-contact sensor 2b is within the detection range 37e. The determination unit 23 determines that interference has occurred if the entire sensor surface 30b of the non-contact sensor 2b is within the detection range 37e. The determination unit 23 determines that no interference has occurred if the entire sensor surface 30b of the non-contact sensor 2b is not within the detection range 37e. For example, as shown in Figure 5, if the entire sensor surface 30b of the non-contact sensor 2b is inside the detection range 37e of the non-contact sensor 2e, the third determination determines that interference has occurred.

[0041] The first, second, and third determinations determine whether the target sensor is interfering with a different non-contact sensor 2. The determination unit 23 then changes the target sensor to another non-contact sensor 2 and performs the interference state determination process again. In other words, each of the multiple non-contact sensors 2 is set as the target sensor, and the interference state with other non-contact sensors 2 is determined.

[0042] When the determination unit 23 determines that interference has occurred, the sensor control unit 24 controls the non-contact sensors 2 that are interfering with each other to avoid interference. Specifically, the sensor control unit 24 controls the multiple non-contact sensors 2 that are interfering with each other in accordance with the posture of the robot 1 to a state in which they do not interfere with each other in that posture.

[0043] Figure 6 shows a first example of avoidance control in the sensor control unit 24. In Figure 6, the case where non-contact sensor 2e and non-contact sensor 2b interfere with each other is shown as an example. Specifically, non-contact sensor 2b is within the detection range 37e of non-contact sensor 2e. Also, non-contact sensor 2e is within the detection range 37b of non-contact sensor 2b. In such a case, the sensor control unit 24 performs control to disable object detection. That is, the sensor control unit 24 disables object detection by non-contact sensor 2e and object detection by non-contact sensor 2b. Disabling means preventing the generation of detection ranges 37e and 37b in non-contact sensor 2e and non-contact sensor 2b, respectively. For example, the generation of electric fields in non-contact sensor 2e and non-contact sensor 2b is stopped. Alternatively, detection ranges 37e and 37b may be generated in non-contact sensor 2e and non-contact sensor 2b, respectively, while control using sensor values ​​is not performed. By disabling object detection in the non-contact sensors 2e and 2b, which interfere with each other in this way, the interference condition is eliminated, and false detections due to interference are suppressed.

[0044] Here, Figure 6 also shows a second example of avoidance control in the sensor control unit 24. The sensor control unit 24 performs control to change the detection range 37 of an object. That is, the sensor control unit 24 changes the detection range 37e of the non-contact sensor 2e and the detection range 37b of the non-contact sensor 2b. Specifically, the sensor control unit 24 changes the detection distance to be shortened (lower sensitivity) for both the detection range 37e and the detection range 37b. Figure 6 shows an example where the detection distance of the detection range 37e is shortened as the detection range 50e, and an example where the detection distance of the detection range 37b is shortened as the detection range 50b. In this way, by shortening the detection distance, the interference condition is eliminated. Specifically, the non-contact sensor 2b will no longer be within the detection range 50e of the non-contact sensor 2e, and the non-contact sensor 2e will no longer be within the detection range 50b of the non-contact sensor 2b. By changing the object detection range 37 in the non-contact sensors 2e and 2b, which interfere with each other in this way, false detections due to interference are suppressed.

[0045] Figure 6 also shows a third example of avoidance control in the sensor control unit 24. The sensor control unit 24 performs control to change the detection direction of an object. That is, the sensor control unit 24 changes the direction of the detection range 37e of the non-contact sensor 2e and the detection range 37b of the non-contact sensor 2b. Specifically, the sensor control unit 24 changes the detection ranges so that the interfering non-contact sensor 2e or non-contact sensor 2b does not enter the range of the detection range 37e and detection range 37b, respectively. Figure 6 shows an example where the direction of the detection range 37e is changed as the detection range 55e, and an example where the direction of the detection range 37b is changed as the detection range 55b. By changing the detection direction in this way, the interference state is resolved. Specifically, the non-contact sensor 2b will no longer be within the detection range 55e of the non-contact sensor 2e, and the non-contact sensor 2e will no longer be within the detection range 55b of the non-contact sensor 2b. By changing the object detection direction in the non-contact sensors 2e and 2b, which interfere with each other in this way, false detections due to interference are suppressed.

[0046] <Processing flow> Figure 7 is a flowchart showing an example of the interference detection process according to this embodiment. Each of the following steps is repeatedly executed at a predetermined control cycle during the operation of the robot 1. That is, the interference detection process is executed in response to the change in posture caused by the operation of the robot 1. The order and content of each of the following steps can be changed as appropriate.

[0047] It is assumed that the multiple non-contact sensors 2 provided on robot 1 are numbered from 1 to M. The number of the non-contact sensor 2 can be specified using variables N and V. Specifically, variable N is a variable that specifies the non-contact sensor 2 as the target sensor. Variable V is a variable that specifies the non-contact sensor 2 that is used to determine whether or not it is interfering with the target sensor. The non-contact sensor 2 specified by variable V will be referred to as the "opponent sensor". Initially, variables N and V are 1 (initial value). Variables N and V are initialized when the following steps are started.

[0048] (Step SP10) The posture determination unit 27 acquires the angles of each rotation axis of the robot 1 and determines the posture of the robot 1. Then, the process proceeds to step SP11.

[0049] (Step SP11) The positioning unit 28 identifies the position of each non-contact sensor 2 installed on the robot 1, corresponding to the posture of the robot 1. Then, the process proceeds to step SP12.

[0050] (Step SP12) The determination unit 23 sets the non-contact sensor 2 corresponding to the variable N as the target sensor. For example, the non-contact sensor 2 for variable N=1 is set as the target sensor. Then, the process moves to step SP13.

[0051] (Step SP13) The determination unit 23 sets the non-contact sensor 2 corresponding to the variable V as the opposing sensor. For example, the non-contact sensor 2 with variable V=1 is set as the opposing sensor. Then, the process moves to step SP14.

[0052] (Step SP14) The determination unit 23 determines whether the variable N that specifies the target sensor and the variable V that specifies the other sensor have the same number. If variable N and variable V are equal, the process proceeds to step SP19. If variable N and variable V are different, the process proceeds to step SP15.

[0053] (Step SP15) The determination unit 23 performs a first determination corresponding to the target sensor specified by variable N and the opposing sensor specified by variable V. If the first determination determines that no interference has occurred, the process proceeds to step SP19. If the first determination does not determine that no interference has occurred, the process proceeds to step SP16.

[0054] (Step SP16) The determination unit 23 performs a second determination corresponding to the target sensor specified by variable N and the other sensor specified by variable V. If the second determination determines that interference has occurred, the process proceeds to step SP18. If the second determination does not determine that interference has occurred, the process proceeds to step SP17.

[0055] (Step SP17) The determination unit 23 performs a third determination corresponding to the target sensor specified by variable N and the opposing sensor specified by variable V. If the second determination determines that no interference has occurred, the process proceeds to step SP19. If the third determination determines that interference has occurred, the process proceeds to step SP18.

[0056] (Step SP18) The sensor control unit 24 performs interference avoidance control on the non-contact sensors 2 (the target sensor of variable N and the opposing sensor of variable V) that interfere with each other. Then, the process moves to step SP19.

[0057] (Step SP19) The determination unit 23 determines whether the variable V is the last number, M. If the variable V is not M, the process proceeds to step SP20. If the variable V is M, the process proceeds to step SP21.

[0058] (Step SP20) The determination unit 23 adds 1 to variable V. Then, the process returns to step SP13 and is executed again. That is, for the target sensor of variable N, a non-contact sensor 2 with a different number (variable V with 1 added) is set as the opposing sensor, and the determination is made.

[0059] (Step SP21) The determination unit 23 determines whether the variable N is the final number M. If the variable N is not M, the process proceeds to step SP22. If the variable N is M, the process ends.

[0060] (Step SP22) The determination unit 23 adds 1 to variable N. The determination unit 23 also resets variable V to its initial value (i.e., 1). Then, the process returns to step SP12, and the process is executed again.

[0061] As described above, it is determined whether the non-contact sensors 2 are interfering with each other, corresponding to the posture of the robot 1 in operation. If interference occurs, countermeasures (avoidance control) are executed. Preferably, after the avoidance control for interference between the non-contact sensors 2 is executed, if the posture of the robot 1 changes to a state where no interference occurs, the avoidance control is released.

[0062] <Effects and Effects> In this embodiment, it is possible to determine whether the non-contact sensor 2 is in an interference state in accordance with the posture of the robot 1. Therefore, it is possible to distinguish whether the non-contact sensor 2 is in a state where it can detect the object to be detected or is detecting another non-contact sensor 2. In other words, false detections by the non-contact sensor 2 can be suppressed. Furthermore, if interference detection is not performed, it is necessary to install the non-contact sensor 2 on the robot 1 so that they do not interfere with each other. However, by performing interference detection and understanding the interference state, it becomes possible to mount more non-contact sensor 2 on the robot 1 or increase the sensor surface area 30 of the non-contact sensor 2. Therefore, the detectable space of objects can be expanded.

[0063] Furthermore, if another non-contact sensor 2 is located within the detection range 37 of the target sensor, it can be determined that interference is occurring between the target sensor and the other non-contact sensor 2.

[0064] Furthermore, by setting the detection range 37 as a three-dimensional region, it becomes possible to determine the presence or absence of interference in three dimensions, thereby improving the accuracy of interference detection.

[0065] Furthermore, if the boundary surface of the detection range 37 of the target sensor intersects with another non-contact sensor 2, or if the entirety of the other non-contact sensor 2 is included inside the detection range 37 of the target sensor, it can be determined that interference is occurring between the target sensor and the other non-contact sensor 2.

[0066] Furthermore, if interference occurs, the interference can be resolved by controlling the non-contact sensors 2 that are interfering with each other to avoid interference. In other words, false detection of objects by the non-contact sensors 2 is suppressed.

[0067] Furthermore, interference can be effectively resolved by performing controls to disable object detection, change the detection range 37, or change the detection direction. In other words, false detection of objects by the non-contact sensor 2 is suppressed.

[0068] ===Unique Text=== This disclosure is not limited to the embodiments described above. In other words, any design modifications made to the above-described examples by those skilled in the art are also included within the scope of this disclosure, as long as they retain the features of this disclosure. Furthermore, the elements of the above embodiments and the following modifications can be combined to the extent that it is technically possible, and any combination thereof is also included within the scope of this disclosure, as long as it retains the features of this disclosure.

[0069] For example, in the above embodiment, the posture determination unit 27 determined the posture of the robot 1 using the angles of each joint of the robot 1, but the method of determining the posture of the robot 1 is not limited. The posture determination unit 27 may determine the posture state of the robot 1 by photographing the robot 1 with a camera or the like and analyzing the image. Alternatively, the posture of the robot 1 may be determined using control signals from the control unit 21 that controls the operation of the robot 1.

[0070] Furthermore, although the above embodiment illustrates the case where the detection range 37 is a rectangular parallelepiped, the detection range 37 can be appropriately set according to the sensor. In other words, the shape, direction, size (distance), etc. of the detection range 37 are not limited to a rectangular parallelepiped and can be set as appropriate.

[0071] Furthermore, although the above embodiments have shown a first example, a second example, and a third example relating to avoidance control, these controls may be combined. Also, avoidance control is not limited to the first example, the second example, and the third example. For example, the angle of the sensor surface 30 may be physically changed.

[0072] Furthermore, in the non-contact sensors 2 installed on the robot 1, the non-contact sensors 2 that may interfere with the operation of the robot 1 may be limited in advance. That is, the combination of non-contact sensors 2 that are subject to interference detection may be limited in advance. By limiting the non-contact sensors 2 in advance, the patterns of non-contact sensors 2 that perform interference detection can be suppressed, thereby improving the efficiency of the processing. The non-contact sensors 2 that may interfere may be limited in accordance with the posture patterns of the robot 1.

[0073] Furthermore, the above embodiment illustrates a case where it is determined whether or not non-contact sensor 2 is interfering with another non-contact sensor 2. Alternatively, the detection range 37 of non-contact sensor 2 may be identified as being in interference with another non-contact sensor 2, and object detection may be performed in the area of ​​the detection range 37 other than the interfering area. [Explanation of symbols]

[0074] 1: Robot 2, 2a~2f: Non-contact sensors 3: Control device (robot control device) 22: Specific part 23: Judgment section 37, 37b, 37e: Detection range

Claims

1. A robot control device for a robot equipped with multiple non-contact sensors, A identification unit that identifies the position of each of the non-contact sensors in accordance with the posture of the robot, A determination unit that designates one of the multiple non-contact sensors as the target sensor and determines, based on the identified position, whether a non-contact sensor other than the target sensor is interfering with the detection range of the target sensor, A robot control device characterized by comprising the following:

2. The robot control device according to claim 1, characterized in that the determination unit determines that interference has occurred when a non-contact sensor different from the target sensor is located within the detection range of the target sensor.

3. The robot control device according to claim 1 or 2, characterized in that the detection range of the target sensor is a range that has been set in advance as a three-dimensional region for the target sensor.

4. The robot control device according to claim 1 or 2, characterized in that the determination unit determines that interference has occurred when the boundary surface of the detection range of the target sensor intersects with a non-contact sensor different from the target sensor, or when the entire non-contact sensor different from the target sensor is located inside the detection range of the target sensor.

5. If the determination unit determines that interference has occurred, the sensor control unit controls the non-contact sensors that are interfering with each other to avoid the interference. The robot control device according to claim 1 or 2, further comprising the above.

6. The robot control device according to claim 5, characterized in that the sensor control unit performs at least one of the following controls on the non-contact sensors that interfere with each other: a control to disable object detection, a control to change the detection range, and a control to change the detection direction.

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