Robot control device and robot system

Abstract

To provide a robot control device capable of interrupting power of a drive part when a part of a computer processing part fails or an encoder fails in the computer processing part outputting a signal to interrupt power of the drive part on the basis of a result of comparison processing between operation command value and encoder value, and a robot system of high safety performance.SOLUTION: A device for controlling a robot includes a drive part driving an arm on the basis of command value and a first encoder part outputting first encoder value, and has a first command value comparison part, a first mutual monitoring part, a second command value comparison part, a second mutual monitoring part, and a power interruption part. The first command value comparison part outputs a first command value comparison result in command value and first encoder value. The second command value comparison part outputs a second command value comparison result in the command value and the first encoder value. The first mutual monitoring part and the second mutual monitoring part output an interruption signal on the basis of the first command value comparison result and the second command value comparison result.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a robot control device and a robot system. [Background technology]

[0002] Patent Document 1 discloses a motor control device having an encoder that detects the operation of a motor, the motor control device including a motor control unit that generates a command value related to the operation of the motor, a drive unit that supplies a drive current to the motor, a cutoff unit that cuts off the transmission of a drive signal from the motor control unit to the drive unit, and a safety control unit that causes the cutoff unit to execute a cutoff process. Of these, the motor control unit generates a command value related to the operation of the motor based on an operation command signal for driving the motor and a feedback signal from the encoder so that the operation of the motor follows the operation command signal.

[0003] The safety control unit of this motor control device determines whether a failure has occurred in the encoder based on the results of a comparison between the feedback value from the encoder and the operation command value calculated from the operation command signal, and causes the cutoff unit to execute a cutoff process based on the results of this determination. With this configuration, encoder failure determination is realized using the results of a comparison between the feedback value from the encoder and the operation command value, thereby improving the safety performance of the motor control device. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-136708 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the safety control unit described in Patent Document 1, if a failure occurs in the encoder, the failure can be determined based on a feedback value from the encoder, and the transmission of the drive signal can be cut off. In this way, the safety control unit described in Patent Document 1 ensures the safety performance required of a motor control device. However, the motor control device described in Patent Document 1 is premised on the safety control unit being sound. Therefore, if the safety control unit breaks down, it is not possible to determine whether or not a failure has occurred in the encoder, and even if a failure has occurred, it is not possible to cut off the transmission of the drive signal. [Means for solving the problem]

[0006] A robot control device according to an application example of the present invention includes: An arm, a drive unit that drives the arm based on an operation command value, and a control unit that detects the operation of the drive unit. put out A robot control device for controlling an operation of a robot having a first encoder unit, a first calculation processing unit having a first command value comparison unit and a first mutual monitoring unit; a second calculation processing unit having a second command value comparison unit and a second mutual monitoring unit; No. 1 The power of the drive unit is cut off based on a cut-off signal. The power supply unit includes a first cutoff unit and a second cutoff unit connected in series with the first cutoff unit and cuts off the power of the drive unit based on a second cutoff signal. A power cut-off unit; having The first command value comparison unit compares the operation command value and the Output from the first encoder Compare with the first encoder value 、 The second command value comparison unit compares the operation command value and the Output from the first encoder Compare with the first encoder value 、 The first mutual monitoring unit and the second mutual monitoring unit each, First command value comparison The comparison process by the Compare the result with the second command value The comparison process by the A mutual command value monitoring process is performed to compare the results with the The first calculation process The part , The first mutual monitoring unit Based on the result of the command value mutual monitoring process , toward the first interrupterThe above No. 1 Outputs a blocking signal death, The second calculation processing unit outputs the second cutoff signal to the second cutoff unit based on a result of the command value mutual monitoring process by the second mutual monitoring unit. vinegar do.

[0007] A robot system according to an application example of the present invention includes: A robot control device according to an application example of the present invention; The robot; The present invention is characterized by having the following. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing a robot system according to an embodiment. [Diagram 2] FIG. 2 is a schematic diagram of the robot shown in FIG. [Diagram 3] FIG. 2 is a block diagram showing a main part of the robot system shown in FIG. 1. [Figure 4] 4 is a detailed diagram of a first joint unit, a robot control device, and a power interruption unit shown in FIG. 3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A robot control device and a robot system according to the present invention will be described in detail below with reference to the embodiments shown in the accompanying drawings.

[0010] First, a robot system and a robot control device according to the embodiment will be described. Fig. 1 is a perspective view showing a robot system according to an embodiment, Fig. 2 is a schematic diagram of the robot shown in Fig. 1, Fig. 3 is a block diagram showing a main part of the robot system of Fig. 1.

[0011] A robot system 1 shown in FIG. 1 is used for various tasks such as transport, assembly, and inspection of various workpieces (objects).

[0012] As shown in FIGS. 1 to 3, the robot system 1 includes a base 4, a robot arm 10, a robot 2 including driving units 401 to 406 and driving control units 301 to 306, and a robot control device 8 that controls the operation of the robot 2.

[0013] 1 and 2 is placed on a horizontal floor 101. Note that the base 4 may be placed on a wall, a ceiling, a stand, or the like instead of the floor 101.

[0014] The robot arm 10 shown in FIG. 1 and FIG. 2 includes a first arm 11, a second arm 12, a third arm 13, a fourth arm 14, a fifth arm 15, and a sixth arm 16. An end effector (not shown) can be detachably attached to the tip of the sixth arm 16, and the end effector can grip a workpiece. The workpiece to be gripped by the end effector is not particularly limited, and examples thereof include electronic components and electronic devices. In this specification, the side of the base 4 when the sixth arm 16 is used as a reference is referred to as the "base end side", and the side of the sixth arm 16 when the base 4 is used as a reference is referred to as the "tip side".

[0015] The end effector is not particularly limited, but examples thereof include a hand that grips a workpiece and a suction head that sucks the workpiece.

[0016] A force detection unit (not shown) may be provided between the sixth arm 16 and the end effector. The force detection unit detects the force applied to the end effector. An example of the force detection unit is a six-axis force sensor that can detect force components (translational force components) in the axial directions of three mutually orthogonal axes and force components (rotational force components) around each of the three axes.

[0017] Furthermore, in addition to the above, the robot system 1 may also include, for example, an image sensor, a depth sensor, an inertial sensor, an ultrasonic sensor, a light curtain, a millimeter wave radar, a laser scanner, and the like.

[0018] 1. Robot The robot 2 is a single-arm, six-axis vertical articulated robot in which a base 4, a first arm 11, a second arm 12, a third arm 13, a fourth arm 14, a fifth arm 15, and a sixth arm 16 are connected in this order from the base end to the tip end. Hereinafter, the first arm 11, the second arm 12, the third arm 13, the fourth arm 14, the fifth arm 15, and the sixth arm 16 are also referred to as "arms". The lengths of the arms 11 to 16 are not particularly limited and can be set appropriately.

[0019] The base 4 and the first arm 11 are connected via a first joint 171. The first arm 11 is rotatable with respect to the base 4 about a first rotation axis O1 parallel to the vertical axis as a rotation center. As shown in FIG. 3, the first joint 171 includes a drive unit 401 having a motor 401M and a reduction gear (not shown), and an angle sensor 411. The first arm 11 rotates when driven by the drive unit 401. The motor 401M generates a driving force that rotates the first arm 11.

[0020] The first arm 11 and the second arm 12 are connected via a second joint 172. The second arm 12 is rotatable with respect to the first arm 11 about a second rotation axis O2 parallel to a horizontal plane. As shown in FIG. 3, the second joint 172 includes a drive unit 402 having a motor 402M and a reduction gear (not shown), and an angle sensor 412. The second arm 12 rotates when driven by the drive unit 402. The motor 402M generates a driving force that rotates the second arm 12.

[0021] The second arm 12 and the third arm 13 are connected via a third joint 173. The third arm 13 is rotatable with respect to the second arm 12 about a third rotation axis O3 parallel to a horizontal plane. As shown in FIG. 3, the third joint 173 includes a drive unit 403 having a motor 403M and a reduction gear (not shown), and an angle sensor 413. The third arm 13 rotates when driven by the drive unit 403. The motor 403M generates a driving force that rotates the third arm 13.

[0022] The third arm 13 and the fourth arm 14 are connected via a fourth joint 174. The fourth arm 14 is rotatable with respect to the third arm 13 about a fourth rotation axis O4 that is parallel to the central axis of the third arm 13. As shown in FIG. 3, the fourth joint 174 includes a drive unit 404 having a motor 404M and a reduction gear (not shown), and an angle sensor 414. The fourth arm 14 rotates when driven by the drive unit 404. The motor 404M generates a driving force that rotates the fourth arm 14.

[0023] The fourth arm 14 and the fifth arm 15 are connected via a fifth joint 175. The fifth arm 15 is rotatable with respect to the fourth arm 14 about a fifth rotation axis O5 that is perpendicular to the central axis of the fourth arm 14. As shown in FIG. 3, the fifth joint 175 includes a drive unit 405 having a motor 405M and a reduction gear (not shown), and an angle sensor 415. The fifth arm 15 rotates when driven by the drive unit 405. The motor 405M generates a driving force that rotates the fifth arm 15.

[0024] The fifth arm 15 and the sixth arm 16 are connected via a sixth joint 176. The sixth arm 16 is rotatable with respect to the fifth arm 15 about a sixth rotation axis O6 that is parallel to the central axis of the tip of the fifth arm 15. As shown in FIG. 3, the sixth joint 176 includes a driving unit 406 having a motor 406M and a reduction gear (not shown), and an angle sensor 416. The sixth arm 16 rotates when driven by the driving unit 406. The motor 406M generates a driving force that rotates the sixth arm 16.

[0025] Examples of the angle sensors 411 to 416 include various encoders such as rotary encoders, etc. The angle sensors 411 to 416 detect the rotation angles of the output shafts of the motors 401M to 406M of the driving units 401 to 406 or the output shafts of the reducers.

[0026] Examples of the motors 401M to 406M of the driving units 401 to 406 include AC servo motors, DC servo motors, and the like.

[0027] The reducers of the driving units 401 to 406 may be, for example, a planetary gear type reducer made up of a plurality of gears, a wave reducer, or the like.

[0028] The driving units 401 to 406 and the angle sensors 411 to 416 are each electrically connected to the robot control device 8.

[0029] The robot control device 8 independently controls the operations of the driving units 401 to 406 via the drive control units 301 to 306. Specifically, the robot control device 8 controls the operating conditions of the driving units 401 to 406, such as the angular velocity and the rotation angle, based on the detection results of the angle sensors 411 to 416 and a force detection unit (not shown).

[0030] 2. Robot control device configuration The robot control device 8 includes a robot controller 81, a robot monitoring unit 82, and a power cutoff unit 85.

[0031] 2.1.Robot Controller The robot controller 81 controls the operation of the drive control units 301 to 306, and thereby controls the operation of the robot 2.

[0032] The hardware configuration of the robot controller 81 is not particularly limited, but in Fig. 3, it includes a processor 912, a memory 914, and an external interface 916. These are connected to each other via an internal bus so as to be able to communicate with each other.

[0033] An example of the processor 912 is a CPU (Central Processing Unit). The processor 912 executes various programs stored in the memory 914 to realize the functions of the robot controller 81.

[0034] The processor 912 may be a field-programmable gate array (FPGA), an application specific integrated circuit (ASIC), or the like.

[0035] Examples of the memory 914 include a volatile memory such as a random access memory (RAM) and a non-volatile memory such as a read only memory (ROM). Note that the memory 914 is not limited to being non-removable, and may be a removable memory.

[0036] The memory 914 stores various programs as well as various data received via the external interface 916 and various data output from the robot 2.

[0037] Examples of the external interface 916 include a Universal Serial Bus (USB), an RS-232C, a wired Local Area Network (LAN), and a wireless LAN.

[0038] As described above, the robot controller 81 having the above-mentioned hardware configuration controls the operation of the drive control units 301-306, and thereby controls the operation of the robot 2. In addition, the robot controller 81 reflects the detection results of the angle sensors 411-416 and the detection results of a force detection unit, an image sensor, a depth sensor, etc. (not shown) in the operation of the robot 2.

[0039] 2.2.Robot Monitoring Unit The robot monitoring unit 82 includes a first arithmetic processing unit 83 and a second arithmetic processing unit 84 as two arithmetic processing units independent of each other.

[0040] The hardware configuration of the first arithmetic processing unit 83 is not particularly limited, but in Fig. 3 it includes a processor 932, a memory 934, and an external interface 936. These are connected to each other via an internal bus so as to be able to communicate with each other.

[0041] The hardware configuration of the second arithmetic processing unit 84 is not particularly limited, but in Fig. 3, it includes a processor 942, a memory 944, and an external interface 946. These are connected to each other via an internal bus so as to be able to communicate with each other.

[0042] The memories 934, 944 and the external interfaces 936, 946 are similar to the memory 914 and the external interface 916 described above.

[0043] The processors 932, 942 each include, for example, a CPU, etc. The processors 932, 942 execute various programs stored in the memories 934, 944 to realize the functions of the robot monitor unit 82.

[0044] In addition, the processors 932 and 942 may each be an FPGA, an ASIC, or the like.

[0045] The robot monitoring unit 82 monitors the operation of the robot 2 independently of the robot controller 81, thereby making it possible to further improve the reliability of the functional safety of the robot system 1.

[0046] 2.3.Power cut-off section Fig. 4 is a detailed diagram of the first joint portion 171, the robot control device 8, and the power interruption unit 85 shown in Fig. 3. The configuration of the first joint portion 171 is similar to the configurations of the second joint portion 172, the third joint portion 173, the fourth joint portion 174, the fifth joint portion 175, and the sixth joint portion 176. Therefore, in the following explanation, the first joint portion 171 will be representatively explained based on Fig. 4 etc., and explanations of the other joint portions will be omitted.

[0047] The power cut-off unit 85 is provided in a power supply path 91 between the power source 9 and the drive unit 401. The drive units 401-406 each receive power from the power supply path 91. Therefore, when the power cut-off unit 85 cuts off the power supply path 91, the power supply to the drive units 401-406 is cut off, and the operation of the drive units 401-406 can be stopped.

[0048] The power cut-off unit 85 shown in FIG. 4 includes a first cut-off unit 851 and a second cut-off unit 852. The first cut-off unit 851 and the second cut-off unit 852 are connected in series with each other. The first cut-off unit 851 and the second cut-off unit 852 each cut off the power supply path 91 based on a cut-off signal. Therefore, when at least one of the first cut-off unit 851 and the second cut-off unit 852 operates, the power supply to the drive units 401 to 406 can be cut off. Therefore, the power cut-off unit 85 can be made redundant.

[0049] 3. Operation of the robot control device 3.1.Comparison of operation command value and encoder value The first joint portion 171 shown in FIG. 4 includes the motor 401M and the angle sensor 411, as described above.

[0050] The angle sensor 411 shown in FIG. 4 includes a first encoder unit 421 and a second encoder unit 422, and is multiplexed. The first encoder unit 421 and the second encoder unit 422 are each connected to, for example, the output shaft of the motor 401M. In this embodiment, the angle sensor 411 is multiplexed to achieve redundancy in detecting the angular position of the output shaft of the motor 401M. As a result, even if an abnormality occurs in one of the first encoder unit 421 and the second encoder unit 422, the angular position of the output shaft of the motor 401M can be detected based on the encoder value output from the other encoder unit.

[0051] The first encoder unit 421 outputs a first encoder value E1 representing the angular position of the output shaft of the motor 401M. The second encoder unit 422 outputs a second encoder value E2 representing the angular position of the output shaft of the motor 401M.

[0052] The robot controller 81 receives the first encoder value E1 and the second encoder value E2, and generates a movement command value M1 based on these encoder values ​​E1, E2. The movement command value M1 controls the movement of the motor 401M and includes a target value for the angular position of the output shaft, i.e., the target values ​​of the encoder values ​​E1, E2.

[0053] The first joint 171 shown in Fig. 4 includes the drive control unit 301 shown in Fig. 3, although not shown. The drive control unit 301 receives the encoder values ​​E1 and E2 as feedback signals, and rotates the output shaft of the motor 401M at a desired angular position, angular velocity, and torque so as to approach a target value specified by the motion command value M1. The robot controller 81 thus controls the first joint 171 to a desired angular position, and as a result, controls the attitude of the first arm 11 relative to the base 4 to a desired attitude.

[0054] The first arithmetic processing unit 83 and the second arithmetic processing unit 84 of the robot monitoring unit 82 receive the operation command value M1, and the first encoder value E1 and the second encoder value E2, respectively.

[0055] The first calculation processing unit 83 shown in Fig. 4 has a first command value comparing unit 832. The first command value comparing unit 832 performs a comparison process between the operation command value M1 and the first encoder value E1, and outputs a first command value comparison result. The first calculation processing unit 83 shown in Fig. 4 also has a first cutoff signal output unit 838. The first cutoff signal output unit 838 outputs a cutoff signal B1 based on the first command value comparison result.

[0056] Specifically, the first command value comparison unit 832 performs a comparison process between the target value of the first encoder value E1 included in the operation command value M1 and the feedback value of the received first encoder value E1. If a first command value comparison result indicating that the target value and the feedback value are equal is output, the first cutoff signal output unit 838 determines that the drive control unit 301, the angle sensor 411, and the like are normal, and does not output a cutoff signal B1. On the other hand, if a first command value comparison result indicating that the target value and the feedback value are different is output, there is a high possibility that an abnormality has occurred in the drive control unit 301, the angle sensor 411, and the like. Since this state is not normal, the first cutoff signal output unit 838 outputs a cutoff signal B1.

[0057] The first cutoff unit 851 receives this cutoff signal B1 and cuts off the power supply path 91. This makes it possible to stop the operations of the drivers 401-406.

[0058] The first command value comparison unit 832 may perform a comparison process between the operation command value M1 and the second encoder value E2, or may perform a comparison process between the operation command value M1 and both the first encoder value E1 and the second encoder value E2.

[0059] The second calculation processing unit 84 shown in Fig. 4 has a second command value comparing unit 842. The second command value comparing unit 842 performs a comparison process between the operation command value M1 and the first encoder value E1, and outputs a second command value comparison result. The second calculation processing unit 84 shown in Fig. 4 also has a second cutoff signal output unit 848. The second cutoff signal output unit 848 outputs a cutoff signal B2 based on the second command value comparison result.

[0060] Specifically, the second command value comparing unit 842 performs a comparison process similar to that of the first command value comparing unit 832. When a second command value comparison result indicating that the target value and the feedback value are equal is output, the second cutoff signal output unit 848 determines that the drive control unit 301, the angle sensor 411, etc. are normal, and does not output cutoff signal B2. On the other hand, when a second command value comparison result indicating that the target value and the feedback value are different is output, there is a high possibility that an abnormality has occurred in the drive control unit 301, the angle sensor 411, etc. Since this state is not normal, the second cutoff signal output unit 848 outputs cutoff signal B2.

[0061] The second cutoff unit 852 receives this cutoff signal B2 and cuts off the power supply path 91. This makes it possible to stop the operations of the drivers 401-406.

[0062] The second command value comparison unit 842 may compare the operation command value M1 with the second encoder value E2, or may compare the operation command value M1 with both the first encoder value E1 and the second encoder value E2.

[0063] As described above, the robot control device 8 according to this embodiment has a function of performing a comparison process between the operation command value M1 and the first encoder value E1 or the second encoder value E2, and outputting the interruption signals B1, B2 based on the comparison result. That is, the robot monitoring unit 82 diagnoses whether the robot 2 is operating normally in response to a command from the robot controller 81, and stops the operation of the robot 2 if an abnormality is detected in the operation. This can improve the safety performance of the robot system 1.

[0064] The above-mentioned comparison process can be performed in the control cycle of the robot monitoring unit 82, for example, in cycles of several milliseconds. Therefore, if any abnormality is detected, the abnormality can be quickly detected and the operation of the robot 2 can be stopped.

[0065] The second cutoff unit 852 may be provided as necessary and may be omitted. In that case, the first cutoff unit 851 may be configured to receive and operate both of the cutoff signals B1 and B2.

[0066] The comparison result that the values ​​are equal or different can be determined by taking into consideration fluctuations in the values ​​due to noise, etc. Also, after performing an arbitrary calculation on at least one of the two values, a comparison process may be performed on the calculated value. This also applies to each comparison process and mutual monitoring process described later.

[0067] 3.2.Comparing joint angles and postures with their respective tolerances The first calculation processing unit 83 shown in Fig. 4 has a first posture comparing unit 834. The first posture comparing unit 834 calculates the joint angle of the first joint unit 171 and the posture of the robot 2 based on parameters related to the robot 2 and the first encoder value E1. The first posture comparing unit 834 then performs a comparison process of the joint angle with its allowable range and a comparison process of the posture with its allowable range, and outputs a first posture comparison result. The first cut-off signal output unit 838 outputs a cut-off signal B1 based on the first posture comparison result.

[0068] Examples of parameters related to the robot 2 include the lengths (link lengths) of the arms 11 to 16 and the reduction ratios of the reducers included in the drive units 401 to 406. The first posture comparison unit 834 calculates the joint angle of the first joint unit 171 based on, for example, the reduction ratios of the reducers and the first encoder value E1. The first posture comparison unit 834 also calculates elements such as the posture of the robot 2, such as the tip position and tip direction of the sixth arm 16, and the positions of each joint, based on, for example, the link length and the first encoder value E1.

[0069] The parameters related to the robot 2 may be stored in advance in a memory unit (not shown) in the first calculation processing unit 83 by the manufacturer or user of the robot system 1 via the robot controller 81, and may also be updated as appropriate.

[0070] Meanwhile, in the first calculation processing unit 83, allowable ranges are set in advance for the joint angle of the first joint unit 171 and the posture of the robot 2. Among these, the allowable range of the joint angle is the range of joint angles allowable for the first joint unit 171 when the robot system 1 is normal. Also, the allowable range of the posture is the range of postures allowable for the robot 2 when the robot system 1 is normal.

[0071] These allowable ranges may be stored in advance in a storage unit (not shown) in the first arithmetic processing unit 83 via the robot controller 81 by the manufacturer or user of the robot system 1, and may be updated as appropriate.

[0072] The first posture comparison unit 834 performs a process of comparing the calculated joint angle with an allowable range and a process of comparing the calculated posture with an allowable range, and outputs a first posture comparison result. Then, when the first posture comparison result is outputted indicating that the calculated joint angle and the calculated posture are both within the allowable range, the first cutoff signal output unit 838 determines that the posture of the robot 2 is normal and does not output the cutoff signal B1. On the other hand, when the first posture comparison result is outputted indicating that the calculated joint angle and the calculated posture are both outside the allowable range, there is a high possibility that an abnormality has occurred in the posture of the robot 2. Since this state is not normal, the first cutoff signal output unit 838 outputs the cutoff signal B1.

[0073] The first cutoff unit 851 receives this cutoff signal B1 and cuts off the power supply path 91. This makes it possible to stop the operations of the drivers 401-406.

[0074] In addition, the first posture comparison unit 834 may calculate the joint angle of the first joint unit 171 and the posture of the robot 2 based on the parameter and the second encoder value E2, or may calculate the joint angle of the first joint unit 171 and the posture of the robot 2 based on the parameter and both the first encoder value E1 and the second encoder value E2.

[0075] The second calculation processing unit 84 shown in Fig. 4 has a second posture comparing unit 844. The second posture comparing unit 844 calculates the joint angle of the first joint unit 171 and the posture of the robot 2 based on parameters related to the robot 2 and the first encoder value E1. The second posture comparing unit 844 then performs a comparison process of the joint angle with its allowable range and a comparison process of the posture with its allowable range, and outputs a second posture comparison result. The second cutoff signal output unit 848 outputs a cutoff signal B2 based on the second posture comparison result.

[0076] Specifically, the second posture comparing unit 844 performs a comparison process similar to that of the first posture comparing unit 834. Then, when a second posture comparison result is output indicating that the calculated joint angle and the calculated posture are both within the allowable range, the second cutoff signal output unit 848 determines that the posture of the robot 2 is normal and does not output the cutoff signal B2. On the other hand, when a second posture comparison result is output indicating that the calculated joint angle and the calculated posture are both outside the allowable range, there is a high possibility that an abnormality has occurred in the posture of the robot 2. Since this state is not normal, the second cutoff signal output unit 848 outputs the cutoff signal B2.

[0077] The second cutoff unit 852 receives this cutoff signal B2 and cuts off the power supply path 91. This makes it possible to stop the operations of the drivers 401-406.

[0078] In addition, the second posture comparison unit 844 may calculate the joint angle of the first joint unit 171 and the posture of the robot 2 based on the parameter and the second encoder value E2, or may calculate the joint angle of the first joint unit 171 and the posture of the robot 2 based on the parameter and both the first encoder value E1 and the second encoder value E2.

[0079] As described above, the robot control device 8 according to this embodiment has a function of performing a comparison process between the joint angle and posture calculated from the parameters related to the robot 2 and the first encoder value E1 or the second encoder value E2, and the previously set allowable range of the joint angle and posture, and outputting the blocking signals B1 and B2 based on the comparison result. That is, the robot monitoring unit 82 diagnoses whether the posture, etc. of the robot 2 deviates from the allowable range specified by the user, for example, and stops the operation of the robot 2 when the deviation is detected. In this way, in this embodiment, since the allowable range can be specified by the user, etc., it is possible to set an appropriate allowable range after the fact in consideration of the operation of the robot 2. This makes it unnecessary to set a uniformly wide allowable range, and it is possible to set an allowable range that is not too wide according to the operation. As a result, it is possible to improve the safety performance of the robot system 1 while suppressing the frequency with which the blocking signals B1 and B2 are output.

[0080] The above-mentioned comparison process can be performed in the control cycle of the robot monitoring unit 82, for example, in cycles of several milliseconds. Therefore, if any abnormality is detected, the abnormality can be quickly detected and the operation of the robot 2 can be stopped.

[0081] 3.3.Comparison of Encoder Values The first encoder unit 421 outputs a first encoder value E1 representing the angular position of the output shaft of the motor 401M. The second encoder unit 422 outputs a second encoder value E2 representing the angular position of the output shaft of the motor 401M. Therefore, the first encoder value E1 and the second encoder value E2 are usually equal.

[0082] The robot control device 8 shown in FIG. 4 includes an encoder value comparison unit 86 provided in the first joint unit 171.

[0083] The encoder value comparator 86 performs a comparison process between the first encoder value E1 and the second encoder value E2 to obtain an encoder value comparison result. Specifically, when the encoder value comparator 86 compares the first encoder value E1 and the second encoder value E2 and obtains an encoder value comparison result indicating that the two are equal, the encoder value comparator 86 determines that the angle sensor 411 is normal and does not output a shutoff signal B3. On the other hand, when the encoder value comparison result indicates that the first encoder value E1 and the second encoder value E2 are different, there is a high possibility that an abnormality has occurred in the angle sensor 411. Since this state is not normal, the encoder value comparator 86 outputs a shutoff signal B3.

[0084] Upon receiving this cutoff signal B3, first cutoff unit 851 and second cutoff unit 852 each cut off power supply path 91. This makes it possible to stop the operations of drive units 401-406.

[0085] 4 includes a first signal relay unit 835. When the first signal relay unit 835 receives the cutoff signal B3, it causes the first cutoff signal output unit 838 to output the cutoff signal B1. That is, the first signal relay unit 835 has a function equivalent to relaying the cutoff signal B3. As a result, the first cutoff unit 851 receives the cutoff signal B1 and cuts off the power supply path 91.

[0086] 4 further includes a second signal relay unit 845. Upon receiving the cutoff signal B3, the second signal relay unit 845 causes the second cutoff signal output unit 848 to output the cutoff signal B2. In other words, the second signal relay unit 845 has a function equivalent to relaying the cutoff signal B3. As a result, the second cutoff unit 852 receives the cutoff signal B2 and cuts off the power supply path 91.

[0087] In this way, when the robot monitoring unit 82 receives the cutoff signal B3, it outputs the cutoff signals B1 and B2. As a result, even if the power cutoff unit 85 cannot receive the cutoff signal B3 due to some kind of obstacle, the power supply path 91 can be cut off by receiving the cutoff signals B1 and B2. As a result, even if the power cutoff unit 85 cannot receive the cutoff signal B3, if there is a possibility that an abnormality has occurred in the first encoder unit 421 or the second encoder unit 422, the operation of the driving units 401 to 406 can be stopped.

[0088] As described above, the robot control device 8 according to this embodiment has a function of performing a comparison process between the first encoder value E1 and the second encoder value E2, and outputting the blocking signals B1 and B2 based on the comparison result. That is, the robot monitoring unit 82 diagnoses whether both the first encoder unit 421 and the second encoder unit 422 are sound or not, and if an abnormality is found in at least one of them, stops the operation of the robot 2. This can improve the safety performance of the robot system 1.

[0089] Furthermore, the robot monitoring unit 82 shown in FIG. 4 receives not only the interruption signal B3 but also the first encoder value E1 and the second encoder value E2.

[0090] The first calculation processing unit 83 performs a comparison process between the first encoder value E1 and the second encoder value E2. When the encoder values ​​E1 and E2 are the same, the first calculation processing unit 83 does not cause the first shutoff signal output unit 838 to output the shutoff signal B1, but when the encoder values ​​E1 and E2 are different, the first calculation processing unit 83 causes the first shutoff signal output unit 838 to output the shutoff signal B1.

[0091] The second calculation processing unit 84 also performs a comparison process between the first encoder value E1 and the second encoder value E2. When the encoder values ​​E1 and E2 are the same, the second calculation processing unit 84 does not cause the second shutoff signal output unit 848 to output the shutoff signal B2, but when the encoder values ​​E1 and E2 are different, the second calculation processing unit 84 causes the second shutoff signal output unit 848 to output the shutoff signal B2.

[0092] By having such a function, the robot monitoring unit 82 can output cut-off signals B1, B2 for cutting off the power supply path 91 when the first encoder value E1 and the second encoder value E2 are different, even if an abnormality occurs in the encoder value comparing unit 86 and the encoder value comparison result cannot be obtained, or an abnormality occurs in the signal path connecting the first joint unit 171 and the power cutting unit 85 and the power cutting unit 85 cannot receive the cut-off signal B3. This ensures the safety performance of the robot system 1 even if multiple abnormalities occur simultaneously, such as an abnormality in the angle sensor 411 and an abnormality in the signal path of the cut-off signal B3.

[0093] The above-mentioned comparison process can be performed in the control cycle of the robot monitoring unit 82, for example, in cycles of several milliseconds. Therefore, if any abnormality is detected, the abnormality can be quickly detected and the operation of the robot 2 can be stopped.

[0094] Furthermore, if multiplexing of the angle sensor 411 is not required, the second encoder unit 422 may be omitted.

[0095] 3.4. Mutual monitoring process The first calculation processing unit 83 shown in FIG. 4 has a first mutual monitoring unit 836. The first mutual monitoring unit 836 receives the second command value comparison result output by the second command value comparison unit 842 from the second calculation processing unit 84. The first mutual monitoring unit 836 performs a command value mutual monitoring process to compare the first command value comparison result output by the first command value comparison unit 832 described above with the received second command value comparison result, and outputs the command value mutual monitoring result. When a command value mutual monitoring result indicating that the first command value comparison result and the second command value comparison result are equal is output, the first calculation processing unit 83 determines that both the first command value comparison unit 832 and the second command value comparison unit 842 are healthy, and the first shutoff signal output unit 838 does not output the shutoff signal B1. On the other hand, when a command value mutual monitoring result is output indicating that the first command value comparison result and the second command value comparison result are different, there is a high possibility that an abnormality has occurred in the first command value comparing unit 832 or the second command value comparing unit 842. Since this state is not normal, the first cutoff signal output unit 838 outputs the cutoff signal B1.

[0096] The first mutual monitoring unit 836 also receives the second posture comparison result output by the second posture comparing unit 844 from the second calculation processing unit 84. The first mutual monitoring unit 836 performs a posture mutual monitoring process to compare the first posture comparison result output by the first posture comparing unit 834 described above with the received second posture comparison result, and outputs the posture mutual monitoring result. When a posture mutual monitoring result indicating that the first posture comparison result and the second posture comparison result are equal is output, the first calculation processing unit 83 determines that both the first posture comparing unit 834 and the second posture comparing unit 844 are healthy, and the first blocking signal output unit 838 does not output the blocking signal B1. On the other hand, when a posture mutual monitoring result indicating that the first posture comparison result and the second posture comparison result are different is output, there is a high possibility that an abnormality has occurred in the first posture comparing unit 834 or the second posture comparing unit 844. Since this state is not normal, the first blocking signal output unit 838 outputs the blocking signal B1.

[0097] The first cutoff unit 851 receives this cutoff signal B1 and cuts off the power supply path 91. This makes it possible to stop the operations of the drivers 401-406.

[0098] The second calculation processing unit 84 shown in FIG. 4 has a second mutual monitoring unit 846. The second mutual monitoring unit 846 receives the first command value comparison result output by the first command value comparing unit 832 from the first calculation processing unit 83. The second mutual monitoring unit 846 performs a command value mutual monitoring process to compare the second command value comparison result output by the second command value comparing unit 842 described above with the received first command value comparison result, and outputs the command value mutual monitoring result. When a command value mutual monitoring result indicating that the second command value comparison result and the first command value comparison result are equal is output, the second calculation processing unit 84 determines that both the second command value comparing unit 842 and the first command value comparing unit 832 are healthy, and the second shutoff signal output unit 848 does not output the shutoff signal B2. On the other hand, when a command value mutual monitoring result is output indicating that the second command value comparison result and the first command value comparison result are different, there is a high possibility that an abnormality has occurred in the second command value comparing unit 842 or the first command value comparing unit 832. Since this state is not normal, the second cutoff signal output unit 848 outputs the cutoff signal B2.

[0099] The second mutual monitoring unit 846 also receives the first posture comparison result output by the first posture comparing unit 834 from the first calculation processing unit 83. The second mutual monitoring unit 846 performs a posture mutual monitoring process to compare the second posture comparison result output by the second posture comparing unit 844 described above with the received first posture comparison result, and outputs the posture mutual monitoring result. When a posture mutual monitoring result indicating that the second posture comparison result and the first posture comparison result are equal is output, the second calculation processing unit 84 determines that both the second posture comparing unit 844 and the first posture comparing unit 834 are healthy, and the second blocking signal output unit 848 does not output the blocking signal B1. On the other hand, when a posture mutual monitoring result indicating that the second posture comparison result and the first posture comparison result are different is output, there is a high possibility that an abnormality has occurred in the second posture comparing unit 844 or the first posture comparing unit 834. Since this state is not normal, the second blocking signal output unit 848 outputs the blocking signal B2.

[0100] The second cutoff unit 852 receives this cutoff signal B2 and cuts off the power supply path 91. This makes it possible to stop the operations of the drivers 401-406.

[0101] As described above, the robot control device 8 according to this embodiment has a function of performing mutual monitoring processing to compare the processing results by the first arithmetic processing unit 83 and the second arithmetic processing unit 84, and outputting blocking signals B1, B2 based on the mutual monitoring results. That is, the robot monitoring unit 82 diagnoses whether both the first arithmetic processing unit 83 and the second arithmetic processing unit 84 are sound or not, and if an abnormality is detected in at least one of them, stops the operation of the robot 2. This can improve the safety performance of the robot system 1.

[0102] The mutual monitoring process as described above can be performed at the control period of the robot monitoring unit 82, for example, at a period of several milliseconds. Therefore, if any abnormality is detected, the abnormality can be quickly detected and the operation of the robot 2 can be stopped.

[0103] Furthermore, in addition to the function of performing the mutual monitoring process described above, the robot control device 8 may have a function of mutually monitoring, for example, the encoder value comparison result received by the first arithmetic processing unit 83 and the encoder value comparison result received by the second arithmetic processing unit 84. This allows the robot control device 8 to diagnose whether or not both the signal path between the first joint unit 171 and the first arithmetic processing unit 83 and the signal path between the first joint unit 171 and the second arithmetic processing unit 84 are sound. If an abnormality is detected, the robot monitoring unit 82 may output blocking signals B1 and B2.

[0104] As described above, the robot control device 8 according to this embodiment is a device that controls the operation of the robot 2 that includes the arms 11-16, the driving units 401-406, and the first encoder unit 421. The driving units 401-406 drive the arms 11-16 based on the operation command value M1. The first encoder unit 421 detects the operation of the driving unit 401 and outputs the first encoder value E1. The robot control device 8 has a first arithmetic processing unit 83, a second arithmetic processing unit 84, and a power interruption unit 85. The first arithmetic processing unit 83 has a first command value comparison unit 832 and a first mutual monitoring unit 836. The second arithmetic processing unit 84 has a second command value comparison unit 842 and a second mutual monitoring unit 846. The first command value comparison unit 832 performs a comparison process between the operation command value M1 and the first encoder value E1, and outputs a first command value comparison result. The second command value comparison unit 842 performs a comparison process between the operation command value M1 and the first encoder value E1, and outputs a second command value comparison result. The first mutual monitoring unit 836 and the second mutual monitoring unit 846 perform a command value mutual monitoring process to compare the first command value comparison result and the second command value comparison result. Then, the first calculation processing unit 83 and the second calculation processing unit 84 output cut-off signals B1, B2 based on the result of the command value mutual monitoring process. The power cut-off unit 85 cuts off the power (electricity) of the drive unit 401 based on the cut-off signals B1, B2.

[0105] According to this configuration, the robot monitoring unit 82 of the robot control device 8 has the first command value comparison unit 832 and the second command value comparison unit 842, as well as the first mutual monitoring unit 836 and the second mutual monitoring unit 846, and therefore can perform a command value mutual monitoring process for comparing the first command value comparison result with the second command value comparison result. Therefore, even if an abnormality occurs in a part of the robot monitoring unit 82, specifically the first mutual monitoring unit 836 or the second mutual monitoring unit 846, or an abnormality occurs in the first encoder unit 421, the robot control device 8 can cut off the power of the drive unit 401 and stop the operation of the arm 11. As a result, when the robot monitoring unit 82 is not healthy, the operation of the robot 2 can be stopped, and therefore a robot system 1 with high safety performance can be realized.

[0106] In this embodiment, the first calculation processing unit 83 outputs a cutoff signal B1 based on the first command value comparison result, and the second calculation processing unit 84 outputs a cutoff signal B2 based on the second command value comparison result.

[0107] According to this configuration, the robot control device 8 can output the cutoff signals B1 and B2 based on the result of the command value mutual monitoring process, as well as output the cutoff signal B1 based on the result of the first command value comparison and output the cutoff signal B2 based on the result of the second command value comparison, thereby further improving the safety performance of the robot system 1.

[0108] The robot 2 also includes a second encoder unit 422 that detects the operation of the driving unit 401 and outputs a second encoder value E2. The robot control device 8 according to this embodiment also includes an encoder value comparison unit 86. The encoder value comparison unit 86 performs a comparison process between the first encoder value E1 and the second encoder value E2, and outputs a blocking signal B3 based on the result of the encoder value comparison.

[0109] According to this configuration, the encoder value comparison unit 86 performs a low-load process of comparing the first encoder value E1 and the second encoder value E2, and outputs a shutoff signal B3 based on the result. By providing such an encoder value comparison unit 86, the robot control device 8 has the function of diagnosing whether both the first encoder unit 421 and the second encoder unit 422 are sound or not, and stopping the operation of the robot 2 when an abnormality is detected in at least one of them. In addition, since the configuration of the encoder value comparison unit 86 can be easily simplified, the probability of failure is low and the shutoff signal B3 can be output in a short time. This further improves the safety performance of the robot system 1.

[0110] Furthermore, the first arithmetic processing unit 83 and the second arithmetic processing unit 84 output cutoff signals B1, B2 based on the encoder value comparison result. As a result, even if the power cutoff unit 85 cannot receive the cutoff signal B3 due to some kind of obstacle, the power supply path 91 can be cut off by receiving the cutoff signals B1, B2. As a result, even if the power cutoff unit 85 cannot receive the cutoff signal B3, if there is a possibility that an abnormality has occurred in the first encoder unit 421 or the second encoder unit 422, the operation of the drive unit 401 can be stopped.

[0111] The first calculation processing unit 83 also has a first posture comparing unit 834. The first posture comparing unit 834 calculates the posture of the robot 2 based on the first encoder value E1. Then, the first posture comparing unit 834 performs a comparison process between the posture of the robot 2 and an allowable range for the posture, and outputs a first posture comparison result.

[0112] According to this configuration, if the first posture comparison result indicates that the posture of the robot 2 is outside the allowable range, the robot control device 8 determines that an abnormality has occurred in the posture of the robot 2, and outputs a blocking signal B1. This can further improve the safety performance of the robot system 1.

[0113] Furthermore, the second calculation processing unit 84 has a second posture comparing unit 844. The second posture comparing unit 844 calculates the posture of the robot 2 based on the first encoder value E1. Then, the second posture comparing unit 844 performs a comparison process between the posture of the robot 2 and an allowable range for the posture, and outputs a second posture comparison result.

[0114] According to this configuration, if the second posture comparison result indicates that the posture of the robot 2 is outside the allowable range, the robot control device 8 determines that an abnormality has occurred in the posture of the robot 2, and outputs a blocking signal B2. This can further improve the safety performance of the robot system 1.

[0115] The first mutual monitoring unit 836 and the second mutual monitoring unit 846 perform a mutual attitude monitoring process to compare the first attitude comparison result with the second attitude comparison result. The first calculation processing unit 83 and the second calculation processing unit 84 output blocking signals B1 and B2 based on the result of the mutual attitude monitoring process.

[0116] According to this configuration, the robot monitoring unit 82 included in the robot control device 8 has a function of outputting cutoff signals B1, B2 based not only on the result of the command value mutual monitoring process in which the first command value comparison result and the second command value comparison result are compared, but also on the result of the posture mutual monitoring process in which the first posture comparison result and the second posture comparison result are compared. This makes it possible to improve the functionality of the robot monitoring unit 82, and even if an abnormality occurs in the first posture comparison unit 834 or the second posture comparison unit 844, it is possible to cut off the power of the driving unit 401 and stop the operation of the arm 11. This makes it possible to further improve the safety performance of the robot system 1.

[0117] Further, the power cut-off unit 85 includes a first cut-off unit 851 that cuts off the power of the drive units 401-406, and a second cut-off unit 852 connected in series with the first cut-off unit 851. The first cut-off unit 851 operates based on a cut-off signal B1 output from the first calculation processing unit 83. The second cut-off unit 852 operates based on a cut-off signal B2 output from the second calculation processing unit 84.

[0118] According to this configuration, when at least one of the first cut-off unit 851 and the second cut-off unit 852 operates, it is possible to cut off the power supply to the drive units 401 to 406. Therefore, the power cut-off unit 85 is made redundant.

[0119] Moreover, the robot system 1 according to this embodiment includes a robot control device 8 and a robot 2. The robot control device 8 includes a robot monitoring unit 82 having a first mutual monitoring unit 836 and a second mutual monitoring unit 846 with mutual monitoring functions, and thus can diagnose the soundness of the robot monitoring unit 82 by detecting an abnormality in the first mutual monitoring unit 836 or the second mutual monitoring unit 846. This makes it possible to realize a robot system 1 with high safety performance, which has a function of stopping the operation of the robot 2 when the robot monitoring unit 82 is not sound.

[0120] Although the robot control device and robot system of the present invention have been described above based on the illustrated embodiment, the robot control device and robot system of the present invention are not limited to the above embodiment, and the configuration of each part can be replaced with any configuration having a similar function. In addition, any other configuration may be added to the robot control device and robot system according to the above embodiment. [Explanation of symbols]

[0121] Reference Signs List 1...robot system, 2...robot, 4...base, 8...robot control device, 9...power supply, 10...robot arm, 11...first arm, 12...second arm, 13...third arm, 14...fourth arm, 15...fifth arm, 16...sixth arm, 81...robot controller, 82...robot monitoring unit, 83...first calculation processing unit, 84...second calculation processing unit, 85...power cut-off unit, 86...encoder value comparison unit, 91...power supply path, 101...floor, 171...first joint unit, 172...second joint unit, 173...third joint joint section, 174...fourth joint section, 175...fifth joint section, 176...sixth joint section, 301...drive control section, 302...drive control section, 303...drive control section, 304...drive control section, 305...drive control section, 306...drive control section, 401...drive section, 401M...motor, 402...drive section, 402M...motor, 403...drive section, 403M...motor, 404...drive section, 404M...motor, 405...drive section, 405M...motor, 406...drive section, 406M...motor, 411...angle sensor, 412...angle sensor ser, 413...angle sensor, 414...angle sensor, 415...angle sensor, 416...angle sensor, 421...first encoder unit, 422...second encoder unit, 832...first command value comparison unit, 834...first attitude comparison unit, 835...first signal relay unit, 836...first mutual monitoring unit, 838...first interruption signal output unit, 842...second command value comparison unit, 844...second attitude comparison unit, 845...second signal relay unit, 846...second mutual monitoring unit, 848...second interruption signal output unit, 851...first interruption unit, 852...second interruption unit, 912...processor, 914...memory, 916...external interface, 932...processor, 934...memory, 936...external interface, 942...processor, 944...memory, 946...external interface, B1...shutdown signal, B2...shutdown signal, B3...shutdown signal, E1...first encoder value, E2...second encoder value, M1...operation command value, O1...first rotating axis, O2...second rotating axis, O3...third rotating axis, O4...fourth rotating axis, O5...fifth rotating axis, O6...sixth rotating axis

Claims

1. A robot control device that controls an operation of a robot including an arm, a drive unit that drives the arm based on an operation command value, and a first encoder unit that detects an operation of the drive unit, a first calculation processing unit having a first command value comparison unit and a first mutual monitoring unit; a second calculation processing unit having a second command value comparison unit and a second mutual monitoring unit; a power cut-off unit including a first cut-off unit that cuts off the power of the drive unit based on a first cut-off signal, and a second cut-off unit that is connected in series with the first cut-off unit and cuts off the power of the drive unit based on a second cut-off signal; having the first command value comparison unit performs a comparison process between the operation command value and a first encoder value output from the first encoder unit; the second command value comparison unit performs a comparison process between the operation command value and a first encoder value output from the first encoder unit; the first mutual monitoring unit and the second mutual monitoring unit each perform a command value mutual monitoring process to compare a result of the comparison process by the first command value comparing unit with a result of the comparison process by the second command value comparing unit; The first calculation processing unit outputs the first cutoff signal to the first cutoff unit based on a result of the command value mutual monitoring process by the first mutual monitoring unit, A robot control device characterized in that the second calculation processing unit outputs the second cut-off signal to the second cut-off unit based on a result of the command value mutual monitoring process by the second mutual monitoring unit.

2. the robot includes a second encoder unit that detects an operation of the driving unit, 2. The robot control device according to claim 1, further comprising an encoder value comparison unit that performs a comparison process between the first encoder value and the second encoder value output from the second encoder unit, and outputs a third interruption signal to the first interruption unit and the second interruption unit based on a result of the encoder value comparison.

3. When the first arithmetic processing unit receives the third cutoff signal, the first arithmetic processing unit outputs the first cutoff signal to the first cutoff unit; The robot control device according to claim 2 , wherein the second calculation processing unit outputs the second cutoff signal to the second cutoff unit when the second calculation processing unit receives the third cutoff signal.

4. the robot includes a plurality of the arms, a plurality of the driving units, the first encoder unit provided for each of the driving units, and the second encoder unit provided for each of the driving units; 4. The robot control device according to claim 2, further comprising the encoder value comparison unit provided for each of the driving units.

5. the first calculation processing unit has a first posture comparison unit that calculates a posture of the robot based on the first encoder value, The robot control device according to claim 1 , wherein the first attitude comparison unit performs a process of comparing the calculated attitude with an allowable range for the attitude.

6. the second calculation processing unit has a second posture comparison unit that calculates a posture of the robot based on the first encoder value, The robot control device according to claim 5 , wherein the second attitude comparison unit performs a process of comparing the calculated attitude with an allowable range for the attitude.

7. the first mutual monitoring unit and the second mutual monitoring unit each perform a mutual attitude monitoring process of comparing a result of the comparison process by the first attitude comparing unit with a result of the comparison process by the second attitude comparing unit; The robot control device according to claim 6 , wherein the first arithmetic processing unit and the second arithmetic processing unit output the first cut-off signal and the second cut-off signal based on a result of the mutual posture monitoring process.

8. the robot includes a second encoder unit that detects an operation of the driving unit, The first arithmetic processing unit performs a comparison process between the first encoder value and the second encoder value output from the second encoder unit, and when the first encoder value and the second encoder value are different from each other, outputs the first cutoff signal to the first cutoff unit; The robot control device according to claim 1 , wherein the second calculation processing unit performs a comparison process between the first encoder value and the second encoder value, and if the first encoder value and the second encoder value differ from each other, outputs the second interruption signal to the second interruption unit.

9. A robot control device according to any one of claims 1 to 8, The robot; A robot system comprising:

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