Industrial Robot Systems

Abstract

The present invention provides an industrial robot system. The industrial robot system includes: a robot having a torque sensor on at least one rotation axis; and a control device (3) for controlling the robot. The control device (3) includes: a torque output unit (31) that outputs a torque value based on the robot's posture or the robot's posture and action; a program storage unit (32) that stores an action program; a drive control unit (34) that causes the robot's structural components to rotate around the rotation axis according to the action program; and an output correction unit (33) that correlates the torque detection value detected by the torque sensor with the torque value output from the torque output unit during the rotation of the structural components around the rotation axis caused by the drive control unit (34).

Description

Technical Field

[0001] The present invention relates to an industrial robot system. Background Art

[0002] There is known an industrial robot such as a cooperative robot that has a torque sensor mounted on at least one axis in order to detect interference with surrounding humans (see, for example, Patent Document 1).

[0003] Generally, in order to maintain accuracy, a torque sensor measures a detection value when a predetermined torque is applied in a state where no torque is applied, and thus the torque sensor is calibrated alone and integrated into an industrial robot for use.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2009-220184 Summary of the invention

[0007] Problem that the invention aims to solve

[0008] However, when the torque sensor is assembled to the robot, the torque sensor itself may be deformed due to the tightening force of the mounting bolts used to assemble the torque sensor to the robot, so that the correction value of the torque sensor calibrated before assembly may not be used.

[0009] In addition, since the output characteristics of a torque sensor are generally nonlinear, there is a problem that when calibrating with high accuracy, it is necessary to perform calibration (matching) in many patterns, which requires a lot of time and labor.

[0010] Solutions for solving problems

[0011] One embodiment of the present invention is an industrial robot system, which comprises: a robot having a torque sensor on at least one rotating axis; and a control device that controls the robot, the control device comprising: a torque output unit that outputs a torque value based on the posture of the robot or the posture and action of the robot; a program storage unit that stores an action program; a drive control unit that causes the structural components of the robot to rotate around the rotating axis according to the action program stored in the program storage unit; and an output correction unit that associates the torque detection value detected by the torque sensor with the torque value output from the torque output unit during the rotational action of the structural components around the rotating axis caused by the drive control unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a diagram showing the overall configuration of an industrial robot system according to one embodiment of the present invention.

[0013] Figure 2 It means that Figure 1 Block diagram of the control device of an industrial robot system.

[0014] Figure 3 It means according to Figure 1 A diagram of an origin position during a calibration operation of a torque sensor of an industrial robot system that detects torque about a third axis.

[0015] Figure 4 It means in Figure 3 A diagram showing a state in which the second arm is rotated in one direction during a calibration operation.

[0016] Figure 5 It means in Figure 3 A diagram showing a state in which the second arm is rotated in another direction during the calibration action.

[0017] Figure 6 Yes means through Figures 3 to 5 A diagram showing an example of the output characteristics of the torque sensor obtained through a calibration operation.

[0018] Figure 7 Yes means Figure 1 An overall structural diagram of a modified example of an industrial robot system.

[0019] Description of reference numerals:

[0020] 1: Industrial robot system

[0021] 2: Robot

[0022] 3: Control device

[0023] 22: Rotating body (structural component)

[0024] 23: First arm (structural component)

[0025] 24: Second arm (structural component)

[0026] 25: Wrist unit (structural component)

[0027] 26, 27, 28: Torque sensor

[0028] 31: Torque output part

[0029] 32: Program storage unit

[0030] 33: Output correction unit

[0031] 34: Drive control unit

[0032] A: First axis (rotation axis)

[0033] B: Second axis (rotation axis)

[0034] C: The third axis (rotation axis) DETAILED DESCRIPTION

[0035] Hereinafter, an industrial robot system 1 according to an embodiment of the present invention will be described with reference to the drawings.

[0036] like Figure 1 As shown, the industrial robot system 1 of the present embodiment includes: a robot 2 ; and a control device 3 that controls the robot 2 .

[0037] The robot 2 is, for example, a vertical articulated robot. The type of the robot 2 is not limited, and any other type of robot 2 may be used.

[0038] The robot 2 comprises: a base 21, which is set on the ground (setting surface); a rotating body (structural component) 22, which is supported in a manner that allows it to rotate around a vertical first axis (rotation axis) A relative to the base 21; a first arm (structural component) 23, which is supported in a manner that allows it to rotate around a horizontal second axis (rotation axis) B relative to the rotating body 22; a second arm (structural component) 24, which has a long axis supported in a manner that allows it to rotate around a horizontal third axis (rotation axis) C relative to the first arm 23; and a wrist unit (structural component) 25, which is supported at the front end of the second arm 24.

[0039] Torque sensors 26 , 27 , 28 for detecting torques around the first axis A, the second axis B, and the third axis C are disposed between the base 21 and the rotating body 22 , between the rotating body 22 and the first arm 23 , and between the first arm 23 and the second arm 24 .

[0040] like Figure 2 As shown, the control device 3 includes a torque output unit 31, a program storage unit 32, an output correction unit 33 of the torque sensors 26, 27, and 28, and a drive control unit 34. The control device 3 is composed of a memory and a processor.

[0041] The torque output unit 31 is a processing unit for outputting a torque value according to the posture of the robot 2 or the posture and movement of the robot 2. Specifically, the torque output unit 31 obtains and outputs a torque value generated by the mass, gravity, and inertia of the structural components connected to the torque sensors 26, 27, and 28 according to the posture of the robot 2 or the posture and movement of the robot 2.

[0042] The torque output unit may also associate the posture of the robot 2 with the torque value, and the rotation angle of the structural component around the rotation axis A, B, C provided with the torque sensors 26, 27, 28 with the torque value, and output the torque value based on the posture of the robot 2 and the rotation angle of the structural component around the rotation axis A, B, C provided with the torque sensors 26, 27, 28. Alternatively, the torque value acting due to the weight and gravity of the structural component connected to the torque sensors 26, 27, 28 may be calculated and output based on the posture of the robot 2. In addition, when the robot 2 moves and decelerates, for example, when accelerating and decelerating and moving at a predetermined position, the inertial force acting on the torque sensors 26, 27, 28 due to the mass of the structural component may be calculated and output.

[0043] More specifically, the torque output unit 31 is a storage unit for outputting a torque value according to the posture of the robot 2 or the posture and movement of the robot 2, and is composed of a memory. The torque output unit 31 may also store data that associates the posture and torque value of the robot 2, and data that associates the rotation angle and torque value of the structural components around the rotation axes A, B, and C equipped with the torque sensors 26, 27, and 28, and outputs the torque value based on the associated data. Alternatively, the torque value calculated according to the posture of the robot 2 and the movement of the robot 2 may be temporarily (indirectly) stored in the torque output unit 31, and the stored torque value may be output by the torque output unit 31.

[0044] When the torque output unit 31 stores data relating the rotation angle of the components around the rotation axes A, B, and C having the torque sensors 26, 27, and 28 and the torque, the rotation angle of the first arm 23 around the second axis B and the torque value caused by the mass acting around the second axis B by the components including the first arm 23, the second arm 24, and the wrist unit 25 are associated with each other, and the rotation angle of the second arm 24 around the third axis C and the torque value acting around the third axis C by the components including the second arm 24 and the wrist unit 25 are associated and stored. As a specific example, creating a table of contents, a correlation graph, or a correlation approximate expression is equivalent to this. Here, the torque value is not caused by an external force, but is a torque of the mechanism of the robot 2 including the components of the robot 2 and the attached tool, etc., acting on the torque sensors 26, 27, and 28.

[0045] Since the masses and dimensions of the components including the first arm 23, the second arm 24, and the wrist unit 25 are known, it is possible to accurately calculate the torque value around the second axis B corresponding to the rotation angle of the first arm 23 around the second axis. In the torque output unit 31, the data of the pre-calculated torque value can be directly stored or indirectly stored.

[0046] When the moment value is stored indirectly, the mass, size or center of gravity position of the structural components including the first arm 23, the second arm 24 and the wrist unit 25 used for calculating the moment is stored, and the moment value can be calculated by calculation using the rotation angle. When the moment value is calculated based on the posture of the robot 2 and the information of each structural component and accessory of the robot 2, the moment value acting with gravity or gravity and the movement of the robot 2 is calculated.

[0047] Here, the torque value acting on the torque sensors 26, 27, 28 changes not only based on the rotation angle of the first axis A, the second axis B, and the third axis C including the rotation axes having the torque sensors 26, 27, 28, but also based on the posture of the robot 2 including the angle of the axis in front of them. Therefore, when the rotation angle and the torque value are associated, it is assumed that the posture of the axis in front of them is a predetermined angle. When there are multiple values ​​as the predetermined angle, it is best to store the data in advance.

[0048] The program storage unit 32 is constituted by a memory, and stores an operation program.

[0049] As the action program, in addition to the action program taught in advance to make the robot 2 perform the operation, there can also be exemplified a calibration program for acquiring information for calibrating the torque sensors 26, 27, and 28. For example, a calibration program for the torque sensor 28 that detects the torque around the third axis C, for example, Figures 3 to 5 As shown, the second arm 24 is rotated in only one direction about the third axis C relative to the first arm 23 and is stopped at a plurality of rotation angles in the middle of the rotation, and the torque detection value output from the torque sensor 28 is stored at this time.

[0050] The output correction unit 33 is composed of a processor, and during the execution of the calibration program, the torque detection value detected by the torque sensors 26, 27, and 28 is associated with the torque output by the torque output unit 31 at each rotation angle, thereby Figure 6 As shown, the output characteristics of the torque sensors 26, 27, and 28 are generated. The output characteristics of the torque sensor 27 that detects the torque about the second axis B are generated together with the output characteristics of the torque sensor 28 that detects the torque about the third axis C.

[0051] On the other hand, when the torque sensor 26 detecting the torque around the first axis A is assumed to be installed on a horizontal ground, a calibration procedure different from that of the torque sensors 27 and 28 is performed. The torque sensor 26 performs calibration based on the output of the torque value during the rotational movement around the first axis A using the mass and center of gravity of the mechanism. When the robot 2 is assumed to be installed on a horizontal ground, the torque generated by gravity acts on the second axis B, the third axis C, and each axis of the wrist unit 25 except the first axis A which is a vertical rotation axis or the first axis A which takes a posture of a vertical rotation axis, so calibration can be performed in a state where the robot 2 is stopped at a predetermined rotation angle.

[0052] However, the moment generated by gravity does not work on the first axis A, so in order to calibrate the first axis A, the posture of the robot 2 around the first axis A is changed, and the calibrated moment is all "0" when the first axis A is stopped. The moment caused by the inertial force that works by moving the first arm 23 of the robot 2 at a fixed speed is used to change the posture of the robot 2 around the first axis A, and calibrate all the moments to a fixed value. Alternatively, it is also possible to calibrate so that the value of the moment when rotating around the first axis A at a fixed speed becomes "0".

[0053] Furthermore, the robot 2 is accelerated or decelerated so as to change the torque value acting on the torque sensor 26, for example, decelerated and stopped at a certain position, and the torque value of the inertial force acting on the torque sensor 26 is used for calibration.

[0054] In this case, the torque output unit 31 calculates and outputs an inertial force caused by the mass of components acting on the torque sensor 26 when the robot 2 moves by accelerating or decelerating according to the posture and operation of the robot 2 .

[0055] What stores the torque detection value output from the torque sensor 26 , which detects the torque about the first axis A, when calibrated in this way, is the calibration program of the torque sensor 26 .

[0056] Here, in the case where the torque sensors 27 and 28 are offset, after the torque sensors 27 and 28 are calibrated, calibration is performed using the torque sensors 27 and 28 based on the torque detection value detected by pressing with a fixed force or torque by the robot 2, or preferably, calibration is performed to calibrate different torque values ​​at certain speeds. As a result, the accuracy of the generated output characteristics is improved.

[0057] When the robot 2 is placed on a table tilted relative to the gravity direction, the torque about the first axis A can be calibrated using the torque value acting on the torque sensors 27 and 28 due to gravity. Therefore, by placing the robot 2 on this platform, the torque sensor 26 can also be calibrated.

[0058] The generated output characteristic is output to and stored in the drive control unit 34. The drive control unit 34 is composed of a processor and a memory.

[0059] Then, when the previously taught operation program is executed, when the torque detection values ​​detected by the torque sensors 26 , 27 , 28 are input, the torque detection values ​​corrected by the output correction unit 33 are calculated based on the stored output characteristics.

[0060] The drive control unit 34 generates a command signal according to the action program read from the program storage unit 32, outputs it to the robot 2, and determines whether the corrected torque detection value exceeds a predetermined threshold value. If it exceeds, the command signal is output to make the robot 2 perform the following specified actions: stop the robot 2, slow down, move in the direction where the force is exerted to avoid it, return to the previous action direction, or execute a pre-prepared action program, etc.

[0061] The operation of the industrial robot system 1 of the present embodiment configured as above will be described below.

[0062] When the industrial robot system 1 of the present embodiment is installed in a factory or the like, the calibration program stored in the program storage unit 32 is executed by the operation of the control device 3 .

[0063] In the calibration procedure, for example, the second arm 24 is rotated about the third axis C relative to the first arm 23 and is kept stationary at a plurality of rotation angles. In this state, the torque detection value output from the torque sensor 28 is read by the output correction unit 33 .

[0064] A torque value is input to the output correction unit 33, and the torque value is associated with the rotation angle of the second arm 24 output from the drive control unit 34 and stored in the torque output unit 31. As a result, an output characteristic that associates the input torque detection value and the torque value is generated in the output correction unit 33. Similarly, an output characteristic is also generated for the torque sensor 27 that detects the torque around the second axis B of the first arm 23 relative to the rotating body 22. The generated output characteristics of each torque sensor 26, 27, and 28 are sent to the drive control unit 34 for storage. Thus, the calibration operation is completed.

[0065] When the pre-taught motion program is read out from the program storage unit 32 and the robot 2 is operated by the drive control unit 34, the torque detection value detected by the torque sensors 26, 27, and 28 is directly input to the drive control unit 34, and the corrected torque detection value is calculated based on the stored output characteristics. Then, it is determined whether the moment or force generated by the action of the external force obtained based on the calculated torque detection value exceeds a predetermined threshold value. If it exceeds, it is determined that the surrounding object is in contact with the robot 2, so that the robot 2 stops or decelerates, or returns to the previous motion direction, or moves in the direction where the force acts to avoid it, or executes the pre-prepared motion program.

[0066] Thus, according to the industrial robot system 1 of the present embodiment, the torque values ​​detected by the torque sensors 26, 27, 28 at a plurality of rotation angles and the torque values ​​stored in the torque output unit 31 (the torque values ​​output by the torque output unit 31) are associated in the output correction unit 33, thereby generating a highly accurately calibrated output characteristic, that is, a relationship of torque with respect to the torque values ​​detected by the torque sensors 26, 27, 28. Thus, there is an advantage that even if the torque sensors 26, 27, 28 are deformed when the torque sensors 26, 27, 28 are assembled to the robot 2, or the torque sensors 26, 27, 28 have strong nonlinear characteristics, the calibration of the torque sensors 26, 27, 28 can be performed simply and accurately in a short time by the automatic operation of the robot 2 itself, as long as the calibration program is executed on the control device 3 of the robot 2.

[0067] In addition, in the present embodiment, an example is given of a case where calibration is performed in a state where accessory structural components such as tools installed on the mechanism portion of the robot 2 are not included, but if the size, weight and center of gravity of the accessory structural components are known, the torque value in a state where the accessory structural components are installed can also be stored in the torque output unit 31.

[0068] This provides an advantage that the torque sensors 26 , 27 , 28 can be recalibrated even in an environment where different tools are attached to each user and the tools cannot be removed.

[0069] Moreover, based on the posture of the robot 2, the mass of the structural components attached to the robot 2 and the value of the center of gravity, the torque value acting on each torque sensor 26, 27, 28 by the mechanism of the robot 2 can be calculated, and the net force acting on each torque sensor 26, 27, 28 can be calculated.

[0070] Furthermore, in the calibration program, the user can arbitrarily change the rotation angle for detecting the set torque. Even in an environment where the range of motion of the robot 2 is limited, the torque sensors 26, 27, 28 can be easily calibrated.

[0071] In addition, in the present embodiment, the following case is described but not limited thereto: the drive control unit 34 performs contact determination with the robot 2 based on the torque and force caused by the action of the external force obtained according to the torque value, which is associated with the detected value detected by the output correction unit 33. Alternatively, for example, the drive control unit 34 can also be used to directly hold the structural components of the robot 2 to perform the guiding operation, so as to reduce the force applied to the robot 2 by the operator, and generate the action command of the robot 2, thereby controlling the auxiliary torque. In this way, the guiding operation can be easily performed.

[0072] In addition, as the industrial robot system 1 of the present embodiment, the robot system in which the base 21 of the robot 2 is set on the ground is described as an example, but instead, Figure 7 As shown, a robot system including a two-axis positioner 50 which is installed on the ground and has a base 21 of the robot 2 installed on the upper surface may be used.

[0073] In this case, the two-axis positioner 50 includes: a base portion 51, which is set on the ground; a swing portion 52, which is supported in a manner that it can swing relative to the base portion 51 around a horizontal swing axis K; and a rotation portion 53, which can rotate relative to the swing portion 52 around a rotation axis L orthogonal to the swing axis K. The base 21 of the robot 2 is set on the upper surface of the rotation portion 53. In addition, the installation of the base portion 51 is not limited to the ground, and can also be a horizontal or downward wall surface as long as it can be installed on a grounded surface. In the present invention, the same is true for other installed surfaces.

[0074] Then, in a state where the robot 2 is set on the rotating part 53 of the two-axis positioner 50, the swing part 52 is swung (rotated) around the swing axis K, thereby tilting the robot 2 with respect to the ground. In this way, the torque around the first axis A can be calibrated using the mass and center of gravity of the mechanism. In addition, by controlling the two-axis positioner 50 with an additional axis, calibration can be performed automatically in a short time.

[0075] In addition, instead of the dual-axis positioner 50, a single-axis positioner can also be used, which includes: a base part 51, which is set on the ground; and a swing part 52, which is supported in a manner that can swing around a horizontal swing axis K relative to the base part 51, and the base 21 of the robot 2 can be set on the upper surface.

[0076] Furthermore, in the present embodiment, a single system in which each torque sensor 26, 27, 28 outputs one torque detection value is exemplified, but instead, the torque sensors 26, 27, 28 may include two or more systems of torque detection units that detect the torque acting on each torque sensor 26, 27, 28. Each torque detection unit detects the torque acting on the torque sensors 26, 27, 28 and outputs it as a torque detection value.

[0077] Furthermore, among the plurality of torque sensors 26, 27, 28 provided in the robot 2, the number of torque detection units provided in each torque sensor 26, 27, 28 can be changed by using the torque sensors 26, 27, 28. Thus, the number of torque detection units can be changed by using the installation portion of the torque sensors 26, 27, 28.

[0078] When the torque sensors 26 , 27 , 28 have two or more systems of torque detection units, the output values ​​of a single or multiple torque detection units and the torque output unit 31 can be associated, and the output correction unit 33 can be used to obtain the corrected, compensated, and modified torque value.

[0079] The output correction unit 33 associates the torque detection value of the torque detection unit of each system with the output value of the torque output unit 31, and outputs the value of the torque that has been corrected, revised, and modified based on the torque detection value. In addition, the output correction unit 33 associates the torque detection values ​​of a plurality of systems, in other words, a plurality of torque detection values, with the output value of the torque output unit 31, and outputs the value of the torque that has been corrected, revised, and modified based on the torque detection value.

[0080] When a detection system of at least two torque sensors 26, 27, and 28 is prepared, and two or more torque values ​​are obtained, and these values ​​are compared and the difference is greater than a threshold value, it is judged that the torque sensors 26, 27, and 28 are faulty. Or, even if the torque detection value of one system cannot be detected due to some influence such as a fault, the torque detection value of other systems can be used to stop the robot 2 quickly and stably.

[0081] Furthermore, by using the output values ​​of the torque detection units of the torque sensors 26 , 27 , 28 a plurality of times and acquiring the torque value from the output correction unit 33 , it is possible to obtain a more accurate torque value in each of the torque sensors 26 , 27 , 28 .

[0082] In addition, at least two systems of torque detection units are provided in each of the torque sensors 26, 27, and 28. However, there is a possibility that a difference occurs in the torque detection values ​​detected due to deformation when the torque sensors 26, 27, and 28 are mounted, imbalance of torque with respect to the torque detection units of at least two systems due to the posture of the robot 2, and the like. In contrast, in each system, the torque detection value detected by each torque detection unit and the torque value output by the torque output unit 31 are associated with each other, thereby absorbing the difference in the output value of the torque detection value of each system, which is caused by the influence of other axis interference caused by forces in directions other than the torque acting on the torque sensors 26, 27, and 28 due to the single-column arm support structure, etc.; uneven stress distribution; deformation when the torque sensors 26, 27, and 28 are mounted; and individual differences in the detection units constituting each system. In addition, the torque actually acting on the torque sensors 26, 27, and 28 can be calculated with high accuracy for two or more systems, and two or more torque values ​​can be obtained from one torque sensor 26, 27, and 28. Furthermore, even when the influence of other-axis interference changes due to a change in the axis angle (arm posture) other than the axis, the axis angle of the other axis that affects the axis is changed, and the torque detection value is correlated with the output value of the torque output unit 31, thereby enabling the torque sensors 26, 27, and 28 to be calibrated with higher accuracy while also taking into account the other-axis interference.

[0083] Similar to the force sensor, the torque sensors 26, 27, and 28 have detection methods such as detection of displacement, deformation, and detection of characteristic changes. At this time, the physical quantities detected include resistance, current, electrostatic capacitance, charge, inductance, light, image, ultrasound, and magnetism.

[0084] The torque sensors 26, 27, and 28 may also include one or more detection units for detecting physical quantities related to the torque. The physical quantity detected by the detection units of the torque sensors 26, 27, and 28 may be any physical quantity that changes due to the applied torque or force, such as a physical quantity that is detected by detecting the displacement of a structure as a change in resistance, electrostatic capacitance, electrochemical quantity, or magnetism.

[0085] In addition, in the present embodiment, as the torque sensors 26, 27, 28, torque sensors that detect the torque acting on the torque sensors 26, 27, 28 may be used, or force sensors that detect force and moment, torque sensors that detect the torque acting around the rotation axes A, B, C, and torque sensors that detect the torque around the rotation axes A, B, C and around other axes may be used.

[0086] Moreover, for the torque sensors 26, 27, and 28, the detection parts of the torque sensors 26, 27, and 28 can be combined or set in the reducer, motor, gear, bearing part, arms 23, 24, etc. that constitute the rotating axis structure of the robot 2, thereby detecting the torque.

[0087] In addition, the torque sensors 26, 27, and 28 can also detect torque by estimating torque based on the current value of the motor or estimating torque based on the command position and current position of the motor. In this way, any structure is possible as long as each torque sensor 26, 27, and 28 can detect torque based on the output value of the detection unit.

[0088] The torque detection value detected by the torque sensors 26 , 27 , and 28 may be a value converted into torque, or a value obtained by converting a physical quantity into analog data or digital data.

[0089] When using the torque sensors 26, 27, and 28 to detect torque, the output correction unit 33 can also be used to associate the output of the detection unit of the torque sensors 26, 27, and 28 with the output of the torque output unit 31, and the output correction unit 33 can be used to detect the accurate torque acting on each torque sensor 26, 27, and 28 from the output of the detection unit of the torque sensors 26, 27, and 28. The torque sensors 26, 27, and 28 detect values ​​converted into torque or physical quantities related to torque.

[0090] The calculation unit may calculate the torque from the physical quantity related to the torque, and may be provided on a printed circuit board and accommodated inside the robot 2 together with the detection units of the torque sensors 26 , 27 , and 28 .

[0091] Moreover, a computing unit may be provided in the control device 3 of the robot 2 to transmit the output value of the detection unit of the torque sensors 26, 27, and 28 to the control device 3 controlling the robot 2 in a wired or wireless manner, and the torque may be calculated by the control device 3 of the robot 2.

[0092] Furthermore, the operation unit may be provided in a control device different from the control device for controlling the robot 2. Furthermore, the output value of the detection unit of the torque sensors 26, 27, 28 may be transmitted to a device different from the control device for controlling the robot 2 by wire or wireless, and the torque may be obtained by the different control device. In this way, the operation unit of the torque sensors 26, 27, 28 may be arranged at the same position as the detection unit of the torque sensors 26, 27, 28, and the industrial robot system 1 of this embodiment may be realized by using the control device 3 which is more suitable.

[0093] In this way, the torque sensors 26, 27, 28 for obtaining the torque acting on the rotation axes A, B, C may include a detection unit for detecting a physical quantity related to the torque and a calculation unit for obtaining the torque based on the detection value of the detection unit.

[0094] Moreover, the output correction unit 33 can also associate the output values ​​of multiple detection units of each system of each torque sensor 26, 27, and 28 with the output value of the torque output unit 31, and output the corrected, compensated, and modified torque value based on the output value of the detection unit of each torque sensor 26, 27, and 28.

[0095] Furthermore, the output correction unit 33 can also associate the output values ​​of the detection units of the multiple systems of each torque sensor 26, 27, 28 with the output value of the torque output unit 31, and output the value of the torque that has been corrected, compensated, and modified based on the output value of the detection unit. Thus, the value of the torque can be obtained with high accuracy in each torque sensor 26, 27, 28.

[0096] When the torque acting on the torque sensors 26, 27, 28 is calculated based on the torque detection value or the output value of the detection unit using the output correction unit 33, any other method may be used as long as it is a method that can associate the output value of the detection unit of the torque sensors 26, 27, 28 with the torque for calibration by using a conversion using a catalog table, an algorithm of a calibration matrix, a linear or nonlinear conversion by a function, etc.

[0097] The above-described embodiments are derived from the various aspects of the present invention disclosed below.

[0098] One embodiment of the present invention is an industrial robot system, which comprises: a robot having a torque sensor on at least one rotating axis; and a control device that controls the robot, the control device comprising: a torque output unit that outputs a torque value based on the posture of the robot or the posture and action of the robot; a program storage unit that stores an action program; a drive control unit that causes the structural components of the robot to rotate around the rotating axis according to the action program stored in the program storage unit; and an output correction unit that associates the torque detection value detected by the torque sensor with the torque value output from the torque output unit during the rotational action of the structural components around the rotating axis caused by the drive control unit.

[0099] According to this scheme, based on the action program stored in the program storage unit, the driving control unit causes the structural component to rotate at least around one rotation axis, and the torque value detected by the torque sensor changes according to the rotation action. The moment value of the structural component around the rotation axis can be calculated with high accuracy for each rotation angle according to the mass and size of the robot's mechanical part.

[0100] Thus, by correlating the torque value detected by the torque sensor in the rotational motion with the torque value output by the torque output unit according to the posture of the robot or the posture and motion of the robot, the output correction unit can generate a calibrated output characteristic with high accuracy, that is, a relationship of the torque value with respect to the torque value detected by the torque sensor. Thus, even if the torque sensor is deformed when it is assembled to the robot or the torque sensor has a strong nonlinear characteristic, the torque sensor can be calibrated with high accuracy in a short time.

[0101] In the above solution, the torque output unit may also have associated data of the posture of the robot and the torque value.

[0102] Moreover, in the above scheme, the torque output unit calculates the torque value acting on the torque sensor based on the posture of the robot or the posture and movement of the robot, and the information of each of the structural components of the robot or the information of each of the structural components and accessory components of the robot.

[0103] The output correction unit may further associate the calculated torque value with the torque detection value detected by the torque sensor.

[0104] Furthermore, in the above aspect, the drive control unit may further perform contact determination of the robot based on the moment value correlated with the torque detection value detected by the torque sensor by the output correction unit.

[0105] According to this structure, when the robot is moving to perform an operation, when the torque or force caused by the action of an external force obtained based on the torque detection value detected by the torque sensor exceeds a predetermined threshold value, it is determined with high precision that interference has occurred between the robot and surrounding objects, and the following predetermined actions can be performed: the robot is stopped accurately, or decelerated to a stop, or returned to the previous direction of movement, or moved in the direction in which the force acts to avoid it, or a pre-prepared action program is executed, etc.

[0106] Moreover, in the above scheme, the drive control unit can also control the auxiliary torque when directly holding the structural component of the robot for guiding operation based on the torque value associated with the torque detection value detected by the torque sensor using the output correction unit.

[0107] Furthermore, in the above aspect, the structural component may be a component of a mechanism portion of the robot that can move around the rotation axis.

[0108] According to this configuration, the torque sensor can be calibrated with high accuracy in a state where a component such as a tool is not mounted on the mechanism portion of the robot.

[0109] Furthermore, in the above aspect, the structural component may further include a component mounted on the mechanism portion of the robot.

[0110] According to this configuration, the torque sensor can be calibrated with high accuracy in a state where a component such as a tool is mounted on the mechanism portion of the robot.

[0111] The above description is always an example, and the present invention is not limited to the above-mentioned embodiments and modifications as long as the features of the present invention are not impaired. The constituent elements of the above-mentioned embodiments and modifications include elements that maintain the identity of the invention and can be replaced and are self-evident. That is, other modes considered within the scope of the technical idea of ​​the present invention are also included in the scope of the present invention.

Claims

1. An industrial robot system, It is characterized in that have: A robot having a torque sensor on at least one rotation axis; and a control device, which controls the robot, The control device has: a torque output unit, which outputs a torque value according to the posture of the robot or the posture and action of the robot; A program storage unit storing an action program; a drive control unit for causing the structural component of the robot to perform a rotational motion around the rotation axis according to the motion program stored in the program storage unit; as well as an output correction unit that generates output characteristics of each of the torque sensors that associates a torque detection value detected by the torque sensor with the torque value output from the torque output unit during the rotational motion of the structural component around the rotation axis caused by the drive control unit, and outputs the generated output characteristics to the drive control unit, The torque output unit has associated data between the posture of the robot and the torque value.

2. The industrial robot system according to claim 1, It is characterized in that The drive control unit performs contact determination of the robot based on the moment value associated with the torque detection value detected by the torque sensor by the output correction unit.

3. The industrial robot system according to claim 1 or 2, It is characterized in that The drive control unit controls the assist torque when the component of the robot is directly grasped for guiding operation, based on the moment value associated with the torque detection value detected by the torque sensor by the output correction unit.

4. The industrial robot system according to claim 1 or 2, It is characterized in that The structural component is a component of a mechanism portion of the robot that is movable around the rotation axis.

5. The industrial robot system according to claim 4, It is characterized in that The structural component includes a component mounted on the mechanism portion of the robot.

6. The industrial robot system according to claim 1 or 2, It is characterized in that The torque sensor includes two or more torque detection units for detecting torque acting on the torque sensor. The output correction unit associates each of the torque detection values ​​detected by the torque detection unit with the moment value.

7. An industrial robot system, It is characterized in that have: A robot having a torque sensor on at least one rotation axis; and a control device, which controls the robot, The control device has: a torque output unit, which outputs a torque value according to the posture of the robot or the posture and action of the robot; A program storage unit storing an action program; a drive control unit for causing the structural component of the robot to perform a rotational motion around the rotation axis according to the motion program stored in the program storage unit; as well as an output correction unit that generates output characteristics of each of the torque sensors that associates a torque detection value detected by the torque sensor with the torque value output from the torque output unit during the rotational motion of the structural component around the rotation axis caused by the drive control unit, and outputs the generated output characteristics to the drive control unit, The torque output unit calculates the torque value acting on the torque sensor based on the posture of the robot or the posture and movement of the robot and the information of each structural component of the robot or each structural component and auxiliary component of the robot. The output correction unit associates the calculated torque value with the torque detection value detected by the torque sensor.

8. The industrial robot system according to claim 7, It is characterized in that The drive control unit performs contact determination of the robot based on the moment value associated with the torque detection value detected by the torque sensor by the output correction unit.

9. The industrial robot system according to claim 7 or 8, It is characterized in that The drive control unit controls the assist torque when the component of the robot is directly grasped for guiding operation, based on the moment value associated with the torque detection value detected by the torque sensor by the output correction unit.

10. The industrial robot system according to claim 7 or 8, It is characterized in that The structural component is a component of a mechanism portion of the robot that is movable around the rotation axis.

11. The industrial robot system according to claim 10, It is characterized in that The structural component includes a component mounted on the mechanism portion of the robot.

12. The industrial robot system according to claim 7 or 8, It is characterized in that The torque sensor includes two or more torque detection units for detecting torque acting on the torque sensor. The output correction unit associates each of the torque detection values ​​detected by the torque detection unit with the moment value.

13. An industrial robot system, It is characterized in that have: A robot having a torque sensor on at least one rotation axis; and a control device, which controls the robot, The control device has: a torque output unit, which outputs a torque value according to the posture of the robot or the posture and action of the robot; A program storage unit storing an action program; a drive control unit for rotating the structural component of the robot around the rotation axis according to the motion program stored in the program storage unit; as well as an output correction unit that generates an output characteristic of each of the torque sensors that associates a detection value detected based on a physical quantity related to torque with the torque value output from the torque output unit during the rotational motion of the structural component around the rotation axis caused by the drive control unit, and outputs the generated output characteristic to the drive control unit, The torque output unit calculates the torque value acting on the torque sensor based on the posture of the robot or the posture and movement of the robot and the information of each structural component of the robot or each structural component and auxiliary component of the robot. The output correction unit associates the calculated torque value with the torque detection value detected by the torque sensor.

14. The industrial robot system according to claim 13, It is characterized in that The torque sensor includes a detection unit that detects the physical quantity related to the torque of two or more systems, and detects the detection value based on the physical quantity, wherein the two or more systems detect the torque acting on the at least one rotating shaft. The output correction unit associates each of the detection values ​​with the torque value.

Images