Robot Control Device

Abstract

A robot control device capable of suppressing erroneous detection in a non-contact sensor is provided. [Solution] The robot control device is a robot control device for a robot provided with multiple non-contact sensors 2e, 2b, and includes an identification unit that identifies the position of each non-contact sensor 2e, 2b in response to the robot's posture, and a judgment unit that designates one of the multiple non-contact sensors 2e, 2b as a target sensor and determines whether a non-contact sensor 2b other than the target sensor is interfering with a predetermined detection range 37e of the target sensor based on each identified position.

Description

[Technical field]

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

[0002] There are cases where humans and robots work together to perform tasks on a workpiece. Robots used in such cases are called collaborative robots. Collaborative robots may be equipped with non-contact sensors that detect nearby objects, such as humans.

[0003] For example, Patent Document 1 describes a robot arm provided with a capacitance-type proximity sensor to detect objects around the robot. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-20287 Summary of the Invention [Problem to be solved by the invention]

[0005] However, a robot may take various postures to perform an operation, which may cause interference between the non-contact sensors provided on the robot. When interference occurs, the non-contact sensors may detect something erroneously.

[0006] In view of the above problems, an object of the present invention is to provide a robot control device that can suppress erroneous detection in a non-contact sensor. [Means for solving the problem]

[0007] In order to solve the above problems, the robot control device of the present invention is a robot control device for a robot provided with a plurality of non-contact sensors, and includes an identification unit that identifies the position of each of the non-contact sensors in accordance with the posture of the robot, and a judgment unit that designates one of the plurality of non-contact sensors as a target sensor and determines whether or not a non-contact sensor other than the target sensor is interfering with a predetermined detection range of the target sensor based on each of the identified positions.

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

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

[0010] In addition, 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 the 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] The robot control device further includes a sensor control unit that, when the determination unit determines that the interference has occurred, controls the non-contact sensors that interfere with each other so as to avoid the interference.

[0012] In addition, in the robot control device, the sensor control unit performs at least one of the following controls for the non-contact sensors that interfere with each other: disabling object detection, changing the detection range, and changing the detection direction. Effect of the Invention

[0013] According to the robot control device of the present invention, it is possible to suppress erroneous detection in the non-contact sensor. [Brief description of the drawings]

[0014] [Figure 1] 1 is a schematic diagram illustrating an example of an overall configuration of a robot system according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram illustrating an example of various functions of the control device of FIG. 1; [Diagram 3] 3 is a diagram illustrating an example of position determination of a non-contact sensor in the position determination unit of FIG. 2. [Figure 4] 2 is a diagram showing an example of a positional relationship among a plurality of non-contact sensors in FIG. 1; [Diagram 5] 1. FIG. 4 is a diagram showing another example of the positional relationship among the plurality of non-contact sensors in FIG. [Figure 6] 3 is a diagram illustrating an example of avoidance control in a sensor control unit in FIG. 2. [Figure 7] 2 is a flowchart showing an example of the flow of an interference determination process in the control device of FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. In order to facilitate understanding of the description, the same reference numerals are used to designate the same components in each drawing, and duplicated description will be omitted as appropriate.

[0016] === Implementation form === <Overall composition> FIG. 1 is a diagram illustrating an example of a schematic overall configuration of a robot system 10 including a controller 3 as a robot controller according to an embodiment of the present invention.

[0017] The robot system 10 is an industrial robot that performs processing such as machining or transporting a workpiece. The robot system 10 is also a collaborative robot that works in the same space as a human, for example.

[0018] As shown in FIG. 1, a 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. 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, a floor surface or a wall surface, and supports the entire robot 1. The first arm A1 is connected to the base 7 via a rotation shaft. The first arm A1 rotates around the rotation shaft relative to the base 7 by a motor (not shown). The second arm A2, the third arm A3, and the fourth arm A4 rotate around their respective rotation shafts 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 arm is connected to the other arms or the like via the rotation shaft as a joint, and is operable. The robot 1 performs a predetermined operation by moving each joint.

[0020] The non-contact sensor 2 is a sensor that detects an object such as a person without contact. In this embodiment, the "object" is a broad concept that includes objects such as a human being and a workpiece. For example, the non-contact sensor 2 detects the approach of an object. The non-contact sensor 2 may also detect the displacement of an object. In this embodiment, a case in which the non-contact sensor 2 detects the approach of an object is taken as an example.

[0021] The non-contact sensor 2 is, for example, a capacitance sensor. The non-contact sensor 2 is not limited to a capacitance sensor as long as it can detect an object in a non-contact manner. For example, the non-contact sensor 2 may be an infrared, ultrasonic, millimeter wave, or LiDAR sensor. In this embodiment, the non-contact sensor 2 will be described as a capacitance sensor.

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

[0023] The non-contact sensor 2 is configured using a detection electrode. The detection electrode is, for example, flat. The detection electrode is, for example, rectangular. The shape of the detection electrode may be designed to match the outer shape of the arm, and is not limited. 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 the non-contact sensor 2 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 forms a capacitance between the detection electrode and a nearby object. The capacitance changes depending on the distance between the detection electrode and the object. The non-contact sensor 2 outputs an output according to the capacitance formed between the detection electrode and the object as a sensor value. The non-contact sensor 2 amplifies a voltage according to the capacitance generated in the detection electrode by an amplifier or the like, and outputs the voltage as a sensor value. The specific circuit configuration of the non-contact sensor 2 is not limited. It should be noted that a known shield electrode, active shield electrode, or the like may be provided on the opposite side (on the main body side of the robot 1) to the direction in which the electric field is generated with respect to the detection electrode.

[0024] In this way, the non-contact sensor 2 outputs a sensor value according to the capacitance (that is, the distance) formed between the non-contact sensor 2 and the object.

[0025] The control device 3 is a robot control device. That is, the control device 3 is an information processing device that controls the operation of the robot 1. The control device 3 is configured with, for example, a CPU, a memory, a communication device, and a storage device, and executes various functions by executing a predetermined program.

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

[0027] The control unit 21 controls the operation of the robot 1. Specifically, the control unit 21 controls the operation of each arm of the robot 1 to cause the robot 1 to execute a predetermined operation. That is, the control unit 21 controls the rotation of each rotation axis constituting 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 operation of the robot 1. Specifically, the control unit 21 compares the sensor value with a threshold value and determines whether or not an object is in proximity to the robot 1. Then, when the control unit 21 determines that an object is in proximity to the robot 1, it stops the operation of the robot 1. For example, when the sensor value increases in response to the approach of an object, the control unit 21 determines that an object is in proximity when the sensor value is equal to or greater than the threshold value. For example, the control unit 21 stops the operation even when the robot 1 is in the middle of a predetermined operation. Note that the control unit 21 is not limited to stopping the operation of the robot 1, and may decelerate the operation of the robot 1.

[0029] The identification unit 22 identifies the positions (coordinates) of the non-contact sensors 2 corresponding to the posture of the robot 1. To this end, the identification unit 22 includes a posture identification unit 27 and a position identification unit .

[0030] The posture identification unit 27 identifies the posture of the robot 1. Specifically, the posture identification unit 27 acquires the angles of the rotation axes constituting the joints of the robot 1. For example, the posture identification unit 27 acquires the angles of the rotation axes (joint angles) from an encoder provided for the rotation axes. Then, the posture identification unit 27 calculates the posture of the robot 1 from the angles of the rotation axes. The posture of the robot 1 is indicated, for example, by the position and direction of the rotation center of each rotation axis constituting the robot 1. The posture identification unit 27 calculates the posture of the robot 1 from the angles of each rotation axis using link parameters. The 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 identification unit 27 calculates the position and direction of the rotation center of each rotation axis from the angle of each rotation axis, and identifies the posture of the robot 1. The posture of the robot 1 is identified, for example, with the base 7, which is a fixed position, as a reference.

[0031] The position identifying unit 28 identifies the position (coordinates) of each non-contact sensor 2 provided on the robot 1 in accordance with the posture of the robot 1. Specifically, the position identifying unit 28 identifies the position of each non-contact sensor 2 using the position and direction of the rotation center of each rotation axis identified by the posture identifying unit 27.

[0032] FIG. 3 is a diagram showing an example of position determination of the non-contact sensor 2. The position determination unit 28 determines 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. FIG. 3 shows an example of a case where the position determination unit 28 determines 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 determined based on the rotation axis corresponding to the fourth arm A4. FIG. 3 shows an example of the rotation center of the rotation axis corresponding to the fourth arm A4 as the rotation center C1, and an example of the direction of the rotation center C1 as the 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 position determination unit 28 determines the position of the non-contact sensor 2e using a sensor position parameter indicating the relative positional relationship between the rotation center C1 and the non-contact sensor 2e. Specifically, the position identifying unit 28 identifies the position of the sensor surface 30e, which is the sensor surface 30, with respect to the rotation center C1. That is, the position identifying unit 28 identifies the position of the non-contact sensor 2e as a three-dimensional offset position with respect to the rotation center C1 and the size of the sensor surface 30e. For example, the position identifying unit 28 identifies the positions of the four corners (corner 31e, corner 32e, corner 33e, corner 34e) of the sensor surface 30e of the non-contact sensor 2e with respect to the rotation center C1. As a result, even if the robot 1 changes its posture, the position of the non-contact sensor 2e corresponding to the posture is identified. In addition, by identifying the position with respect to the rotation center C1, the detection direction of the object by the sensor surface 30e of the non-contact sensor 2e (for example, the direction in which the electric field is generated) is identified.

[0033] In this manner, the position specifying unit 28 specifies the position of the sensor surface 30e of the non-contact sensor 2e in accordance with the posture of the robot 1. Then, the position specifying unit 28 specifies the position of the sensor surface 30e of the non-contact sensor 2e in accordance with the posture of the robot 1. To Similarly, the position of the sensor surface 30 corresponding to the posture of the robot 1 is identified.

[0034] Returning to FIG. 2, the determination unit 23 determines an interference state between the 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. The interference state is a state in which at least a part of a non-contact sensor 2 is included in a detection range 37 of another non-contact sensor 2. The detection range 37 is a range in which an object can be detected by the non-contact sensor 2, and is set in advance corresponding to each non-contact sensor 2. Specifically, the detection range 37 is set in advance as a three-dimensional area for the non-contact sensor 2. In this embodiment, the detection range 37 is a rectangular parallelepiped area extending from the sensor surface 30 of the non-contact sensor 2.

[0035] The determination unit 23 determines one of the multiple non-contact sensors 2 as a "target sensor." Then, it determines whether or not the target sensor interferes with a non-contact sensor 2 other than the target sensor. That is, the determination unit 23 determines whether or not a non-contact sensor 2 other than the target sensor is located within the detection range 37 of the target sensor. That is, the determination unit 23 determines whether or not the sensor surface 30 of the non-contact sensor 2 other than the target sensor is located within the detection range 37 of a rectangular parallelepiped extending from the sensor surface 30 of the target sensor.

[0036] FIG. 4 is a diagram showing an example of the positional relationship between a target sensor and a non-contact sensor 2 different from the target sensor. FIG. 4 shows a non-contact sensor 2e as the target sensor. FIG. 4 also shows a non-contact sensor 2b as a non-contact sensor 2 different from the target sensor. That is, FIG. 4 shows the positional relationship between the sensor surface 30e of the non-contact sensor 2e, the position of which is specified by the position specifying unit 28, and the sensor surface 30b of the non-contact sensor 2b. Then, a rectangular parallelepiped 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 with four corners constituting the sensor surface 30e and four corners, i.e., corners 42e, 43e, 44e, and 45e of a boundary surface 41e that is a predetermined detection distance away from the sensor surface 30e. The side surfaces between the sensor surface 30e and the boundary surface 41e are four surfaces, namely, a boundary surface 46e, a boundary surface 47e, a boundary surface 48e, and a boundary surface 49e. The sensor surface 30b of the non-contact sensor 2b has four sides, namely, a side 51b, a side 52b, a side 53b, and a side 54b.

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

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

[0039] Then, the determination unit 23 performs a second determination. Specifically, the determination unit 23 determines whether or not the boundary surfaces of the detection range 37e of the non-contact sensor 2e, which is the target sensor, intersect with the non-contact sensor 2b, which is the non-contact sensor 2 different from the target sensor. The boundary surfaces are six surfaces, namely, the sensor surface 30e, the boundary surface 41e, the boundary surface 46e, the boundary surface 47e, the boundary surface 48e, and the boundary surface 49e, corresponding to the detection range 37e. The boundary surfaces may be five surfaces excluding the sensor surface 30e. Then, the determination unit 23 determines whether or not each of the boundary surfaces intersects with the sensor surface 30b of the non-contact sensor 2b. Specifically, the determination unit 23 determines whether or not an intersection occurs between each of the boundary surfaces and each side (side 51b, side 52b, side 53b, side 54b) of the sensor surface 30b of the non-contact sensor 2b. Then, the determination unit 23 determines that interference has occurred when even a partial intersection occurs between each of the boundary surfaces and each of the sides of the sensor surface 30b of the non-contact sensor 2b. In this case, a part (not the whole) of the non-contact sensor 2b is included within the range of the detection range 37e of the non-contact sensor 2e, which means that interference has occurred. Furthermore, the determination unit 23 performs a third determination when no intersection occurs between each of the boundary surfaces and each of the sides of the sensor surface 30b of the non-contact sensor 2b. Note that the determination unit 23 may determine that no interference has occurred when no intersection occurs between the boundary surfaces and the sides of the sensor surface 30b. For example, in the case of FIG. 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] Then, the determination unit 23 performs a third determination. Specifically, the determination unit 23 determines whether or not the entirety of the non-contact sensor 2b, which is a non-contact sensor 2 different from the target sensor, is located inside the detection range 37e of the non-contact sensor 2e, which is the target sensor. That is, the determination unit 23 determines whether or not the entirety of the sensor surface 30b of the non-contact sensor 2b is within the area of ​​the detection range 37e. Then, the determination unit 23 determines that interference has occurred when the entirety of the sensor surface 30b of the non-contact sensor 2b is within the area of ​​the detection range 37e. Furthermore, the determination unit 23 determines that interference has not occurred when the entirety of the sensor surface 30b of the non-contact sensor 2b is not within the area of ​​the detection range 37e. For example, as shown in FIG. 5, when the entirety of the sensor surface 30b of the non-contact sensor 2b is within the inside of the detection range 37e of the non-contact sensor 2e, it is determined in the third determination that interference has occurred.

[0041] The first, second, and third judgments determine whether or not the target sensor interferes with a non-contact sensor 2 different from the target sensor. Then, the judgment unit 23 changes the target sensor to the other non-contact sensor 2, and performs the interference state judgment process again. That is, each of the multiple non-contact sensors 2 is set as a target sensor, and the interference state with the other non-contact sensor 2 is judged.

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

[0043] FIG. 6 is a diagram showing a first example of avoidance control in the sensor control unit 24. FIG. 6 shows an example in which the non-contact sensor 2e and the non-contact sensor 2b interfere with each other. Specifically, the non-contact sensor 2b is within the range of the detection range 37e of the non-contact sensor 2e. In addition, the non-contact sensor 2e is within the range of the detection range 37b of the non-contact sensor 2b. In such a case, the sensor control unit 24 performs control to invalidate the detection of the object. That is, the sensor control unit 24 invalidates the object detection by the non-contact sensor 2e and the object detection by the non-contact sensor 2b. The invalidation is to prevent the detection range 37e and the detection range 37b from being generated in the non-contact sensor 2e and the non-contact sensor 2b, respectively. For example, the generation of an electric field is stopped in the non-contact sensor 2e and the non-contact sensor 2b. In addition, the control using the sensor value may not be performed while the detection range 37e and the detection range 37b are generated in the non-contact sensor 2e and the non-contact sensor 2b, respectively. By disabling the detection of an object by the non-contact sensor 2e and the non-contact sensor 2b that interfere with each other in this manner, the interference state is eliminated and erroneous detection due to the interference state is suppressed.

[0044] Here, FIG. 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 the 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 performs a change in the direction of shortening the detection distance (reducing the sensitivity) for each of the detection ranges 37e and 37b. FIG. 6 shows an example in which the detection distance of the detection range 37e is shortened as a detection range 50e, and an example in which the detection distance of the detection range 37b is shortened as a detection range 50b. In this way, the interference state is eliminated by shortening the detection distance. Specifically, the non-contact sensor 2b does not enter within the detection range 50e of the non-contact sensor 2e, and the non-contact sensor 2e does not enter within the detection range 50b of the non-contact sensor 2b. In this manner, by changing the object detection range 37 of the non-contact sensor 2e and the non-contact sensor 2b that interfere with each other, erroneous detection due to an interference state is suppressed.

[0045] FIG. 6 also shows a third example of the avoidance control in the sensor control unit 24. The sensor control unit 24 performs control to change the detection direction of the 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 performs the change so that the non-contact sensor 2e or the non-contact sensor 2b that interferes with the detection range 37e and the detection range 37b does not enter the range. FIG. 6 shows an example in which the direction of the detection range 37e is changed as a detection range 55e, and an example in which the direction of the detection range 37b is changed as a detection range 55b. In this way, the interference state is eliminated by changing the detection direction. Specifically, the non-contact sensor 2b does not enter the range of the detection range 55e of the non-contact sensor 2e, and the non-contact sensor 2e does not enter the range of the detection range 55b of the non-contact sensor 2b. In this way, by changing the object detection directions of the non-contact sensors 2e and 2b that interfere with each other, erroneous detection due to the interference state is suppressed.

[0046] <Processing flow> 7 is a flowchart showing an example of the flow of the interference detection process according to this embodiment. The following steps are repeatedly executed at a predetermined control period while the robot 1 is in operation. That is, the interference detection process is executed in response to the posture that changes due to the operation of the robot 1. Note that the order and content of the following steps can be changed as appropriate.

[0047] It is assumed that the multiple non-contact sensors 2 provided on the robot 1 are assigned numbers from 1 to M. It is assumed that the numbers of the non-contact sensors 2 can be specified by the variables N and V. Specifically, the variable N is a variable that specifies the non-contact sensor 2 as the target sensor. The variable V is a variable that specifies the non-contact sensor 2 that determines whether or not there is interference with the target sensor. The non-contact sensor 2 specified by the variable V is referred to as the "opponent sensor." In the initial state, the variables N and V are 1 (initial value). The variables N and V are initialized when starting the following steps.

[0048] (Step SP10) The posture identification unit 27 acquires the angles of the rotation axes of the robot 1 and identifies the posture of the robot 1. Then, the process proceeds to step SP11.

[0049] (Step SP11) The position specifying unit 28 specifies the position of each of the non-contact sensors 2 provided on the robot 1 in accordance with the posture of the robot 1. Then, the process proceeds to step SP12.

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

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

[0052] (Step SP14) The determination unit 23 determines whether the variable N designating the target sensor and the variable V designating the other sensor are the same number. If the variables N and V are equal, the process proceeds to step SP19. If the variables N and 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 designated by the variable N and the counterpart sensor designated by the variable V. If it is determined in the first determination that no interference is occurring, the process proceeds to step SP19. If it is not determined in the first determination that no interference is occurring, the process proceeds to step SP16.

[0054] (Step SP16) The determination unit 23 performs a second determination corresponding to the target sensor designated by the variable N and the other sensor designated by the variable V. If it is determined in the second determination that interference is occurring, the process proceeds to step SP18. If it is determined in the second determination that interference is not occurring, the process proceeds to step SP17.

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

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

[0057] (Step SP19) The judgment unit 23 judges whether the variable V is the final 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 the variable V. Then, the process returns to step SP13, and the process is executed again. That is, for the target sensor of the variable N, the non-contact sensor 2 with a different number (the variable V with 1 added) is set as the counterpart sensor, and a determination is performed.

[0059] (Step SP21) The judgment unit 23 judges whether or not 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 judgment unit 23 adds 1 to the variable N. The judgment unit 23 also returns the 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, whether or not the non-contact sensors 2 are interfering with each other is determined according to the posture of the robot 1 during operation, and if interference is occurring, a countermeasure (avoidance control) is executed. Note that, after executing interference avoidance control for the interfering non-contact sensors 2, if the posture of the robot 1 changes to a state where no interference occurs, it is preferable to cancel the interference avoidance control.

[0062] <Action and effect> As described above, in this embodiment, it is possible to determine whether the non-contact sensor 2 is in an interference state according to 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 target to be detected or is in a state where it is detecting another non-contact sensor 2. In other words, it is possible to suppress erroneous detection by the non-contact sensor 2. Furthermore, if interference determination is not performed, it is necessary to install the non-contact sensors 2 on the robot 1 so that they do not interfere with each other. However, by performing interference determination and being able to grasp the interference state, it is possible to mount more non-contact sensors 2 on the robot 1 and to increase the sensor surface 30 of the non-contact sensor 2. Therefore, it is possible to expand the space in which objects can be detected.

[0063] Furthermore, when 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 area, it becomes possible to determine the presence or absence of interference in three dimensions, improving the accuracy of interference determination.

[0065] In addition, 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 state can be resolved by controlling the non-contact sensors 2 to avoid the interference. In other words, erroneous detection of an object by the non-contact sensors 2 is suppressed.

[0067] In addition, by performing control to disable object detection, control to change the detection range 37, and control to change the detection direction, the interference state can be effectively eliminated. In other words, erroneous detection of an object by the non-contact sensor 2 is suppressed.

[0068] === Variations === The present disclosure is not limited to the above-mentioned embodiment. In other words, the above-mentioned specific example, to which a person skilled in the art appropriately adds design modifications, is also included in the scope of the present disclosure as long as it has the features of the present disclosure. In addition, each element of the above-mentioned embodiment and the following modified examples can be combined to the extent technically possible, and the combination of these is also included in the scope of the present disclosure as long as it has the features of the present disclosure.

[0069] For example, in the above embodiment, the posture identifying unit 27 identifies the posture of the robot 1 using the angles of each joint of the robot 1, but the method of identifying the posture of the robot 1 is not limited. The posture identifying unit 27 may identify the posture state of the robot 1 by photographing the robot 1 with a camera or the like and analyzing the photograph. Also, the posture of the robot 1 may be identified using a control signal from the control unit 21 that controls the operation of the robot 1.

[0070] In the above embodiment, the detection range 37 is a rectangular parallelepiped, but the detection range 37 can be set appropriately according to the sensor. That is, the shape, direction, size (distance), etc. of the detection range 37 are not limited to a rectangular parallelepiped and can be set appropriately.

[0071] In addition, in the above embodiment, the first, second, and third examples of the avoidance control are shown, but each control may be combined. Also, the avoidance control is not limited to the first, second, and third examples. For example, the angle of the sensor surface 30 may be physically changed.

[0072] Furthermore, among the non-contact sensors 2 provided on the robot 1, the non-contact sensors 2 that may interfere with the operation of the robot 1 may be limited in advance. In other words, the combination of non-contact sensors 2 that are the subject of interference determination may be limited in advance. By limiting the non-contact sensors 2 in advance, the pattern of the non-contact sensors 2 that perform interference determination can be suppressed, making it possible to improve the efficiency of processing. The non-contact sensors 2 that may interfere may be limited in accordance with the posture pattern of the robot 1.

[0073] Also, in the above embodiment, the case where it is determined whether or not the non-contact sensor 2 interferes with another non-contact sensor 2 is described as an example. It is also possible to specify which part of the detection range 37 of the non-contact sensor 2 interferes with the other non-contact sensor 2, and perform object detection in an area of ​​the detection range 37 other than the interfering part. [Explanation of symbols]

[0074] 1:Robot 2, 2a to 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 provided with a plurality of non-contact sensors, an identification unit that identifies a position of each of the non-contact sensors in response to a posture of the robot; a determination unit that determines whether or not a non-contact sensor other than the target sensor interferes with a detection range of the target sensor that is set in advance, based on each of the identified positions, and determines whether or not the non-contact sensor other than the target sensor interferes with the detection range of the target sensor that is set in advance, based on each of the identified positions; A robot control device comprising:

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

3. 3. The robot control device according to claim 1, wherein the detection range of the target sensor is a range that is set in advance as a three-dimensional area 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 a boundary surface of the detection range of the target sensor intersects with the non-contact sensor different from the target sensor, or when the entirety of the non-contact sensor different from the target sensor is located inside the detection range of the target sensor.

5. a sensor control unit that controls the non-contact sensors interfering with each other so as to avoid the interference when the determination unit determines that the interference has occurred; The robot control device according to claim 1 or 2, further comprising:

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

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