JP2017094446A - Robot control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a robot control device capable of guaranteeing safe stop of a robot 10 by a monitoring section 24 even when an abnormality occurs in a robot system.SOLUTION: A control device 20 includes: a control section 23 which outputs a control signal for driving control of a robot 10; a driving section 21 which inputs the control signal and drives a motor 41 for driving of the robot 10; and a power supply cut-off section 22 which switches an electrical connection state between the driving section 21 and a power source 40 to either a conduction state or a cut-off state. The control device 20 further includes a monitoring section 24 which switches the connection state of the power supply cut-off section 22 to the cut-off state when detecting an abnormality in a robot system. The control device 20 is configured so that the control section 23 is not capable of directly performing a switching operation of the power supply cut-off section 22. The control section 23 outputs an instruction for switching the connection state of the power supply cut-off section 22 to the cut-off state to the monitoring section 24 when detecting the abnormality in the robot system.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a robot control apparatus that constitutes a robot system including a robot having a plurality of rotating units and a motor that drives a rotating shaft of each rotating unit.

  As this type of control device, as can be seen in the following Patent Document 1, electric power is supplied from a control unit that outputs a control signal for driving control of a motor and an external power source through first to third electromagnetic contactors. A device that is configured to be operable by being supplied and includes a drive unit that drives a motor with a control signal output from the control unit as an input is known. The control unit has a function of monitoring the presence or absence of an abnormality of the robot based on position data from an encoder that detects the rotational position of the rotary shaft. A control part switches a 1st electromagnetic contactor from a conduction | electrical_connection state to a interruption | blocking state, when abnormality of a robot is detected. As a result, power supply from the external power source to the drive unit is interrupted, and the robot is stopped.

  The control device further includes a monitoring unit that is completely independent from the control unit. The monitoring unit has a function of monitoring the presence or absence of abnormality of the robot based on the position data from the encoder. When the monitoring unit detects an abnormality of the robot, the monitoring unit switches the second and third electromagnetic contactors from the conduction state to the cutoff state. As a result, power supply from the external power source to the drive unit is interrupted, and the robot is stopped.

  As described above, in the control device described in Patent Document 1 below, the control unit and the monitoring unit independently monitor the presence or absence of abnormality of the robot, thereby guaranteeing the stop of the robot. That is, in the control device described in Patent Document 1, it is possible to guarantee the stop of the robot only with the control unit in consideration of the case where the monitoring unit is not provided.

Japanese Patent No. 5271499

  In order to prevent an operator from entering the operation area of the robot in the production line, safety measures have been conventionally taken to enclose the operation area with a safety protection fence. In recent years, it has been considered that a robot and an operator work together in a production line in order to improve the efficiency of product production. In this case, since there is a possibility that the safety protection fence is not installed, it is necessary to take safety measures in place of the safety protection fence. In order to take this safety measure, the monitoring unit is an essential component of the control device.

  In the control device described in Patent Document 1, a control unit that is independent of the monitoring unit as well as the monitoring unit monitors whether there is an abnormality in the robot, and interrupts power supply when an abnormality is detected. For this reason, even if no abnormality has occurred in the robot, if an abnormality occurs in the control unit, the first electromagnetic contactor may be inadvertently switched by the control unit during the operation of the robot. . As a result, the first electromagnetic contactor is blocked by the control unit separately from the blocking of the second and third electromagnetic contactors by the monitoring unit. When the shut-off is performed, when the motor is stopped, the motor deceleration process is performed in a state where control by the control unit is left. In a situation where control by the control unit is away from the control unit, a robot operation that does not occur under the control of the control unit may be performed. Such an operation is often different from a normal control operation under the control of the control unit, and may be an unexpected operation of the robot. If the robot performs an unexpected motion, there is a risk of anxiety for the worker who works in cooperation with the robot. Therefore, there is a possibility of affecting the safe stop of the robot by the monitoring unit.

  The present invention has been made to solve the above problem, and it is a main object of the present invention to provide a robot control device that can guarantee a safe stop of a robot by a monitoring unit even when an abnormality occurs in a robot system. It is the purpose.

  1st invention comprises the robot system provided with the robot which has a some rotation part and the motor which drives the rotating shaft of each said rotation part, The robot control apparatus which drives and controls the said robot WHEREIN: The drive of the said robot A control unit that outputs a control signal for control; and a drive unit configured to be operable by being supplied with electric power from an external power source and driving the motor with the control signal output from the control unit as an input; A power cutoff unit that switches an electrical connection state between the driving unit and the external power source to either a conduction state or a cutoff state; and a function of monitoring whether the robot system is abnormal or not. When the abnormality is detected, the power cutoff unit is switched to switch the connection state of the power cutoff unit from the conduction state to the cutoff state. The robot control device is configured so that the control unit cannot directly switch the power shut-off unit, and the control unit has a function of monitoring whether there is an abnormality in the robot system. And when abnormality of the said robot system is detected, the instruction | indication which switches the connection state of the said power supply interruption | blocking part from the said conduction | electrical_connection state to the said interruption | blocking state is output with respect to the said monitoring part, It is characterized by the above-mentioned.

  In the above invention, the monitoring unit has a function of monitoring whether there is an abnormality in the robot system. When the monitoring unit detects an abnormality in the robot system, the monitoring unit switches the power cutoff unit so as to switch the connection state of the power cutoff unit from the conduction state to the cutoff state. As a result, power supply from the external power source to the drive unit is interrupted, and the robot is stopped. In the above invention, the control unit has a function of monitoring whether there is an abnormality in the robot system. When detecting an abnormality in the robot system, the control unit outputs an instruction to switch the connection state of the power supply cutoff unit from the conduction state to the cutoff state to the monitoring unit. When the switching instruction is input to the monitoring unit, the monitoring unit finally switches the connection state of the power cutoff unit to the cutoff state. As a result, power supply from the external power source to the drive unit is interrupted, and the robot is stopped.

  Here, the configuration in which the monitoring unit finally switches the connection state of the power cut-off unit to the cut-off state is because the robot control device of the above invention is configured so that the control unit cannot directly switch the power cut-off unit. Is provided. That is, for example, in the conventional configuration in which the control unit can switch the power cut-off unit as described in Patent Document 1, the control unit itself malfunctions in a situation where the connection state of the power cut-off unit should be switched to the cut-off state. The control unit is controlled so that the connection state is maintained in the conductive state, and there is a possibility that the connection state of the power cutoff unit cannot be switched to the cutoff state. On the other hand, in the said invention, since a control part cannot perform switching operation of a power-supply-cutoff part directly, such a problem does not generate | occur | produce. For this reason, according to the said invention, even if it is a case where abnormality arises in a control part, it can prevent that a power supply interruption | blocking part is inadvertently switched by the control part. For this reason, according to the said invention, the safe stop of the robot by a monitoring part can be ensured.

  Moreover, according to the said invention, the motor stop process can also be performed under control by a control part between the time concerning the switch instruction | indication to a power-supply-cutoff part and the progress of the interruption process by a power supply interruption | blocking part. For this reason, it is possible to reduce a period during which an unexpected motion of the robot occurs. Further, since the period for the switching instruction to the power shut-off unit and the progress of the shut-off process by the power shut-off unit is an initial stage of the motor stop start, the motor operation amount is large. Therefore, by performing the motor stop process when the motor operation amount is large, an unexpected large operation of the robot can be suppressed, and the safety of the robot system can be further improved.

  Furthermore, according to the said invention, the operation | work for obtaining the certification | authentication of a third party organization about the part which concerns on the safety | security of a robot control apparatus can be facilitated. In other words, the authentication target range of the third party organization includes a configuration for switching the power cutoff unit. For this reason, in the control device described in Patent Document 1, when the control unit that directly switches the electromagnetic contactor is improved, it is proved that the improvement does not affect the function of safely stopping the robot by the monitoring unit. There is a risk that the workload of On the other hand, in the above invention, since the control unit is configured not to directly switch the power shut-off unit, even when the control unit is improved, the improvement is a safe stop of the robot by the monitoring unit. It becomes easy to prove that it does not affect. Therefore, according to the said invention, when improving a control part, the operation | work for obtaining authentication can be facilitated and the workload for obtaining authentication can be reduced.

  In a second aspect of the present invention, when the control unit detects an abnormality of the robot, the control unit further outputs a signal for stopping the robot as the control signal to the drive unit.

  In the above invention, when a robot abnormality is detected, a signal for stopping the robot is further output from the control unit to the drive unit. For this reason, the means for stopping the robot can be doubled. Moreover, in the above invention, in addition to stopping the robot by cutting off the power supply to the drive unit, the robot can also be stopped by control. Note that a signal for stopping the robot while performing a predetermined operation may be employed as the signal for stopping the robot.

  According to a third aspect of the present invention, each of the control unit and the monitoring unit has a function of monitoring the presence or absence of an abnormality, and the monitoring unit detects the abnormality of the control unit, When the control unit detects an abnormality of the monitoring unit, a signal for stopping the robot is used as the control signal when switching the power cutoff unit so as to switch the connection state from the conduction state to the cutoff state. Is output to the drive unit.

  In the above invention, the robot can be stopped even when an abnormality occurs in either the monitoring unit or the control unit. Further, even when an abnormality occurs in the monitoring unit, the control unit can stop the robot by a signal for stopping the robot, instead of directly switching the power cutoff unit.

  According to a fourth aspect of the present invention, the robot system includes a rotation detection unit that detects rotation position information of the rotation shaft, and the control unit detects the rotation position information detected by the rotation detection unit and its command information. If the deviation of the robot is determined to be greater than or equal to a predetermined amount, it is detected that an abnormality has occurred in the robot, and when the abnormality of the robot is detected, the connection state of the power shut-off unit is changed from the conduction state to the cutoff state. An instruction to switch to a state is output to the monitoring unit.

  In the above invention, the control unit detects an abnormality of the robot when it is determined that the deviation between the rotational position information detected by the rotation detection unit and the command information is a predetermined amount or more. If an abnormality occurs in the robot, the drive control of the robot becomes impossible and the deviation becomes large. Therefore, according to the invention, the abnormality of the robot can be detected with high accuracy.

The figure which shows the outline | summary of a robot system. The figure which shows the structure of a safety controller. The flowchart which shows the procedure of the process of the control part which concerns on abnormality detection. The flowchart which shows the procedure of the process of the monitoring part which concerns on abnormality detection.

  Hereinafter, an embodiment embodying a robot control device will be described with reference to the drawings. The robot according to the present embodiment is used in an assembly system such as a machine assembly factory as an industrial robot, for example.

  First, the outline of the robot system according to the present embodiment will be described with reference to FIG.

  As shown in FIG. 1, the robot 10 constituting the robot system includes a plurality of rotating units and joints that connect the rotating units to each other. The robot 10 according to the present embodiment is configured as a 6-axis vertical articulated robot.

  The robot 10 includes a fixed portion 11 that is fixed to a floor or the like, and a first rotating portion 12 that is provided above the fixed portion 11. The arm of the robot 10 includes a lower arm 13, an upper arm 14, a wrist portion 15, and a hand portion 16 in addition to the first rotating portion 12. The 1st rotation part 12 is equivalent to the root part on the opposite side to the arm tip part among the both ends of an arm. The first rotating unit 12 is rotatable in the horizontal direction with a first axis J1 extending in the vertical direction as a rotation center.

  The first rotating portion 12 is connected to the lower end portion of the lower arm 13 as the second rotating portion so as to be rotatable clockwise or counterclockwise about a second axis J2 extending in the horizontal direction as a rotation center. . The upper arm 14 is coupled to the upper end of the lower arm 13 so as to be rotatable clockwise or counterclockwise about a third axis J3 extending in the horizontal direction. The upper arm 14 is configured to be divided into two arm portions on the base end side (the joint side having the third axis J3 as the rotation center during rotation) and the tip end side, and the base end side is the third rotation. The first upper arm 14A (third rotating part) as a part, and the tip side is a second upper arm 14B (fourth rotating part) as a fourth rotating part. The second upper arm 14B is rotatable in the torsional direction with respect to the first upper arm 14A, with a fourth axis J4 extending in the longitudinal direction of the upper arm 14 as a rotation center.

  A wrist portion 15 as a fifth rotating portion is provided at the distal end portion of the second upper arm 14B. The wrist portion 15 is rotatable with respect to the second upper arm 14B with a fifth axis J5 extending in the horizontal direction as a rotation center. A hand portion 16 as a sixth rotating portion for attaching a work, a tool, or the like is provided at the distal end portion of the wrist portion 15. The hand portion 16 is rotatable in the torsional direction with the sixth axis J6 that is the center line as the rotation center. A TCP (Tool Center Point) that is the center point 16a of the hand unit 16 is set as a control point.

  Each rotating part of the robot 10 is driven by a motor 41 (see FIG. 2) provided correspondingly. The motor 41 can rotate in both forward and reverse directions, and each rotating unit is driven by the drive of the motor 41 with reference to the origin position.

  The robot system further includes a controller 20 that controls the robot 10 and a teaching pendant 30 that is electrically connected to the controller 20. The teaching pendant 30 includes a microcomputer including a CPU, ROM, and RAM, various manual operation keys, a display, and the like. The pendant 30 can communicate with the controller 20. The operator can manually operate the pendant 30 to create, modify, register, and set various parameters for the operation program of the robot 10. In teaching for correcting an operation program or the like, a teaching point through which a TCP as a control point passes in the work is taught. The operator can operate the robot 10 through the controller 20 based on the teaching operation program.

  Next, the electrical configuration of the robot system will be described with reference to FIG.

  The controller 20 includes a drive unit 21 that drives a motor 41 using an external power supply 40 as a power supply source. In the present embodiment, the drive unit 21 is configured as an intelligent power module (IPM) including a three-phase inverter that converts a DC voltage into an AC voltage and applies it to the stator winding of the three-phase motor 41. Note that the motor 41 and the inverter are individually provided corresponding to each of the rotating parts of the robot 10.

  The controller 20 includes a power cutoff unit 22 provided on an electrical path connecting the power source 40 and the drive unit 21. In this embodiment, a contactor (electromagnetic contactor) is used as the power cutoff unit 22. The power cut-off unit 22 electrically connects the power source 40 and the drive unit 21 when the connection state is made conductive, and the power supply 40 and the drive unit 21 are made when the connection state is turned off. Is electrically disconnected. Note that an emergency stop switch is provided on the electrical path connecting the power source 40 and the drive unit 21 and on the electrical path outside the controller 20 to switch the electrical path to either the conduction state or the cutoff state by manual operation. Is provided.

  The controller 20 includes a control unit 23 that performs drive control of the motor 41. The control unit 23 is configured mainly with a microprocessor, and is configured to be able to acquire an output signal of an encoder 42 as a rotation detection unit that detects rotation position information of the motor 41. The encoder 42 is provided individually corresponding to each motor 41. The control unit 23 outputs a PWM signal, which is a control signal, to the drive unit 21 in order to control the control amount (for example, rotation speed) of each motor 41 to the command value.

  The controller 20 includes a monitoring unit 24 that monitors whether the robot 10 and the control unit 23 are abnormal. The monitoring unit 24 is configured to be able to acquire the output signal of the encoder 42. When the monitoring unit 24 detects an abnormality in at least one of the robot 10 and the control unit 23, the monitoring unit 24 switches the power supply cutoff unit 22 from the conduction state to the cutoff state. In the present embodiment, the controller 20 is configured so that only the monitoring unit 24 can directly switch the power shut-off unit 22 in the controller 20. For this reason, the control unit 23 cannot directly switch the power supply cutoff unit 22. That is, in the present embodiment, the control unit 23 and the power cutoff unit 22 are not directly connected by the signal line.

  In the present embodiment, each of the control unit 23 and the monitoring unit 24 has a function of monitoring each other for the presence or absence of an abnormality. Moreover, in this embodiment, the control part 23, the monitoring part 24, the power supply interruption | blocking part 22, and the drive part 21 are accommodated in the common housing | casing 20a.

  The configuration in which the control unit 23 cannot directly switch the power cutoff unit 22 is provided to prevent the robot 10 from performing an unexpected operation when an abnormality occurs in the control unit 23. That is, in the configuration in which the control unit 23 can directly switch the power cutoff unit 22, when an abnormality occurs in the control unit 23, the power cutoff unit 22 is inadvertently switched by the control unit 23 during the operation of the robot 10. There is a risk. Specifically, for example, the control unit 23 may inadvertently switch the power cutoff unit 22 to the cutoff state. In this case, the robot 10 may perform an unexpected operation and may cause anxiety to an operator who works in cooperation with the robot 10. Further, for example, there is a possibility that the power cutoff unit 22 is switched by the control unit 23 so that the conduction state and the cutoff state are alternately repeated. In this case, in addition to the robot 10 performing an unexpected operation, the power shut-off unit 22 may be welded.

  In order to solve such a problem, the controller 20 is configured so that the controller 23 cannot directly switch the power shut-off unit 22. Hereinafter, among the processes performed by the controller 20, the processes of the control unit 23 and the monitoring unit 24 related to abnormality detection will be described.

  First, the process of the control part 23 is demonstrated using FIG. This process is repeatedly executed by the control unit 23 at a predetermined cycle, for example.

  In this series of processing, first, in step S10, it is determined whether or not at least one abnormality of the robot 10 and the monitoring unit 24 is detected. Hereinafter, the abnormality detection methods of the robot 10 and the monitoring unit 24 will be described.

  The abnormality detection method of the robot 10 will be described. In this embodiment, when it is determined that the deviation between the rotation angle of the rotation axis based on the rotation position information detected by the encoder 42 and the command angle thereof is a predetermined amount or more, the robot It is determined that 10 abnormalities are detected. The command angle is, for example, a command rotation angle of each rotation axis determined by PTP control when the drive control of the robot 10 is performed by PTP control, and is controlled when the drive control is performed by CP control. It is a rotation angle of each rotation axis calculated by performing an inverse conversion process on the command value of the point.

  On the other hand, an abnormality detection method of the monitoring unit 24 will be described. In the present embodiment, an abnormality of the monitoring unit 24 is detected based on a watchdog timer.

  If it is determined in step S10 that an abnormality has been detected, the process proceeds to step S11, and an instruction to switch the connection state of the power cutoff unit 22 from the conduction state to the cutoff state is output to the monitoring unit 24. Thereby, the power supply from the power supply 40 to the drive unit 21 is interrupted. Also, the output of the PWM signal to the drive unit 21 is stopped. Thereby, the drive control of the robot 10 is stopped.

  Next, processing of the monitoring unit 24 will be described with reference to FIG. This process is repeatedly executed by the monitoring unit 24 at a predetermined cycle, for example.

  In this series of processes, first, in step S20, it is determined whether or not an abnormality has been detected in at least one of the robot 10 and the control unit 23. Here, the abnormality detection method of the robot 10 may be the same method as the method described in step S10 of FIG. Moreover, the abnormality detection method of the control part 23 should just employ | adopt the abnormality detection method based on a watchdog timer, as demonstrated by step S10 of previous FIG.

  When it determines with abnormality being detected in step S20, it progresses to step S21 and switches the power supply interruption | blocking part 22 from a conduction | electrical_connection state to a interruption | blocking state by energization operation. Thereby, the power supply from the power supply 40 to the drive unit 21 is interrupted.

  On the other hand, if it is determined in step S20 that no abnormality has been detected, the process proceeds to step S22, and it is determined whether or not the control unit 23 has received an instruction to switch the power supply cutoff unit 22 to the cutoff state. When an affirmative determination is made in step S22, the process proceeds to step S21, and the power shut-off unit 22 is switched from the conduction state to the cutoff state.

  The embodiment described in detail above has the following advantages.

  In the robot system, the controller 20 is configured so that only the monitoring unit 24 can directly switch the power shut-off unit 22. When detecting an abnormality in at least one of the robot 10 and the monitoring unit 24, the control unit 23 outputs an instruction to switch the connection state of the power supply cutoff unit 22 from the conduction state to the cutoff state to the monitoring unit 24. When the switching instruction is input to the monitoring unit 24, the monitoring unit 24 finally switches the connection state of the power cutoff unit 22 to the cutoff state. Thereby, the power supply from the power supply 40 to the drive unit 21 is cut off, and the robot 10 is stopped. According to such a configuration, even if an abnormality occurs in the control unit 23, the power cutoff unit 22 can be prevented from being inadvertently switched by the control unit 23. Therefore, it is possible to guarantee a safe stop of the robot 10 by the monitoring unit 24 without giving anxiety to the worker who performs the cooperative work with the robot 10.

  Furthermore, the operation | work for obtaining the certification | authentication of a 3rd party organization about the part which concerns on the safety | security of the controller 20 can be made easy. In other words, the authentication target range of the third party organization includes a configuration in which the power cutoff unit 22 is directly switched. In the present embodiment, since the control unit 23 is configured not to directly switch the power cutoff unit 22, even when the control unit 23 is improved, the improvement directly switches the power cutoff unit 22. The monitoring unit 24 is not affected. Therefore, according to the present embodiment, when the control unit 23 is improved, the work for obtaining authentication can be facilitated, and the work load for obtaining authentication can be reduced.

  In order to obtain authentication, it is necessary to provide the power cutoff unit 22 for the monitoring unit 24 individually. Here, the control device described in Patent Document 1 needs to include three electromagnetic contactors by separately providing a power cutoff unit for the control unit and the first and second monitoring units. On the other hand, in the present embodiment, since the control unit 23 does not directly switch the power cutoff unit 22, the power cutoff unit 22 may be provided only for the monitoring unit 24. Thereby, the number of the power supply interruption | blocking parts 22 can be reduced.

  When detecting an abnormality of the robot 10, the control unit 23 stops outputting the PWM signal to the drive unit 21. For this reason, it is possible to double the means for stopping the robot 10 together with the configuration in which the power cutoff unit 22 is switched to the cutoff state by the monitoring unit 24.

  When each of the control unit 23 and the monitoring unit 24 determines that the deviation between the rotation angle calculated based on the rotation position information of the encoder 42 and the command angle is a predetermined amount or more, an abnormality has occurred in the robot 10. Detected. This detection method is a highly reliable abnormality detection method because the rotation angle of each rotation axis is a parameter that can accurately grasp the operation state of each rotation unit of the robot 10. For this reason, in this embodiment, it is possible to accurately detect that an abnormality has occurred in the robot 10.

  Each of the control unit 23 and the monitoring unit 24 has a function of monitoring whether or not there is an abnormality. When the monitoring unit 24 detects an abnormality in the control unit 23, the monitoring unit 24 switches the power supply cutoff unit 22 so that the connection state of the power supply cutoff unit 22 is switched from the conduction state to the cutoff state. When the control unit 23 detects an abnormality in the monitoring unit 24, the control unit 23 stops outputting the PWM signal to the drive unit 21. According to this configuration, the robot 10 can be stopped regardless of which of the monitoring unit 24 and the control unit 23 is abnormal.

(Other embodiments)
In addition, the said embodiment can also be changed and implemented as follows.

  In the above embodiment, the abnormality detection target by the control unit 23 and the monitoring unit 24 may include other components of the robot system such as the power shut-off unit 22 in addition to the robot 10.

  -The abnormality detection method of the robot 10 by the control part 23 and the monitoring part 24 is not restricted to what was shown in the said embodiment. For example, when it is determined that the current control point calculated based on the rotational position information has deviated from a predetermined operating range, or when the rotational speed of the current rotational axis calculated based on the rotational position information is greater than or equal to a specified speed. If determined, an abnormality of the robot 10 may be detected.

  If a positive determination is made in step S10 of FIG. 3, a PWM signal that stops the robot 10 while applying a dynamic brake to the robot 10 may be output. The dynamic brake is to decelerate and stop the motor 41 by operating the inverter so as to form a closed circuit including a stator winding of the motor 41 and an inverter switch of the drive unit 21.

  In addition, when an affirmative determination is made in step S10 of FIG. 3, a PWM signal that stops the robot 10 may be output while causing the robot 10 to perform an operation such that the rotating unit of the robot 10 moves away from the operator. Specifically, for example, a PWM signal for stopping the robot 10 is output while turning the first rotating unit 12 around the first axis J1 so that the center point 16a of the robot 10 is separated from a predetermined operator's work space. do it. Information relating to the work space of the worker is stored in advance in the memory of the controller 20, for example.

  In the above embodiment, a plurality of monitoring units 24 may be provided. In this case, each monitoring unit may switch the common power cutoff unit, or each monitoring unit may switch the power cutoff unit provided individually for each monitoring unit. .

  In the above embodiment, the control unit 23 may not stop outputting the PWM signal when detecting an abnormality of the robot 10.

  The power cutoff unit 22 is not limited to a contactor, and may be a semiconductor switch such as an IGBT.

  In the above embodiment, the drive unit 21 may not be accommodated in the housing 20a, and at least the power shut-off unit 22, the control unit 23, and the monitoring unit 24 may be accommodated in the housing 20a.

  The robot is not limited to a vertical articulated type, but may be a horizontal articulated type, for example.

  DESCRIPTION OF SYMBOLS 10 ... Robot, 20 ... Controller, 21 ... Drive part, 22 ... Power supply interruption part, 23 ... Control part, 24 ... Monitoring part, 41 ... Motor.

Claims (4)

In a robot control device comprising a robot having a plurality of rotating units and a motor that drives a rotating shaft of each rotating unit, and driving and controlling the robot,
A control unit for outputting a control signal for driving control of the robot;
A drive unit configured to be operable by power supplied from an external power source, and driving the motor with the control signal output from the control unit as an input;
A power cutoff unit that switches an electrical connection state between the driving unit and the external power source to either a conduction state or a cutoff state;
The function of monitoring whether there is an abnormality in the robot system, and when the abnormality of the robot system is detected, the power cutoff unit is switched to switch the connection state of the power cutoff unit from the conduction state to the cutoff state. A monitoring unit for operation,
The robot control device is configured so that the control unit cannot directly switch the power shut-off unit,
The control unit has a function of monitoring the presence or absence of an abnormality of the robot system, and when detecting an abnormality of the robot system, an instruction to switch the connection state of the power cut-off unit from the conduction state to the interruption state. A robot controller characterized by outputting to a monitoring unit.   2. The robot control device according to claim 1, wherein, when the abnormality of the robot is detected, the control unit further outputs a signal for stopping the robot as the control signal to the drive unit. 3. Each of the control unit and the monitoring unit has a function of monitoring each other for the presence or absence of an abnormality,
When the monitoring unit detects an abnormality of the control unit, the monitoring unit switches the power cutoff unit so as to switch the connection state of the power cutoff unit from the conduction state to the cutoff state,
The robot control device according to claim 1, wherein the control unit outputs a signal for stopping the robot as the control signal to the driving unit when detecting an abnormality of the monitoring unit. The robot system includes a rotation detection unit that detects rotation position information of the rotation shaft,
When the control unit determines that the deviation between the rotation position information detected by the rotation detection unit and the command information is a predetermined amount or more, the control unit detects that an abnormality has occurred in the robot, and the robot The robot control device according to any one of claims 1 to 3, wherein when an abnormality is detected, an instruction to switch the connection state of the power shut-off unit from the conductive state to the shut-off state is output to the monitoring unit. .

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