Provided are: a position command calculation unit which calculates a position command specifying a target position of a driven body driven by a servomotor; a counterforce command. calculation unit which calculates a counterforce command specifying a target, counterforce which should be received by the driven body; a position acquisition unit which acquires an actual position of the driven body; a position reference drive control unit which generates a position reference drive signal so as to bring the position nearer the target position; a counterforce acquisition unit which acquires a counterforce being received by the driven body; a counterforce reference drive control unit which generates a counterforce reference drive signal so as to bring the counterforce nearer the target counterforce; and a drive signal selection unit which selects either one of the position reference drive signal and the counterforce reference drive signal; in which the position command calculation unit calculates the position command so that the target position becomes a second order or higher relationship relative to time, and the counterforce command calculation unit calculates the counterforce command so that a relationship between the target counterforce and the target position becomes substantially linear.

Motion control of a robot arm is performed via a reducer connected to a motor. A controller thereof includes a thrust control unit that generates motor position command value based on an input thrust command value, and a motor control unit that generates a current value based on the motor position command value. The motor control unit feeds back a motor position detected by a motor encoder, and the thrust control unit feeds back thrust detected by a thrust meter. The feedback from the motor control unit suppresses vibration phenomena at the reducer, and the feedback from the thrust control unit suppresses transmission error, thereby enabling motion control of the arm with rapidity and precision.

A failure diagnostic device includes a torque detector that detects disturbance torques applied to joint shafts included in a multi-axis robot, a torque grouping circuit that groups the disturbance torques according to a content of an operation executed by the multi-axis robot upon detection of each disturbance torque, a torque correction circuit that obtains a corrected disturbance torque standardized between a plurality of operations with different contents based on a representative value preliminarily set for each grouped disturbance torque and the disturbance torque detected by the torque detector, and a failure diagnostic circuit that performs a failure diagnosis on the multi-axis robot by comparing the corrected disturbance torque with a threshold.

Provided are: a position command calculation unit which calculates a position command specifying a target position of a driven body driven by a servomotor; a counterforce comm and. calculation unit which calculates a counterforce command specifying a target, counterforce which should be received by the driven body; a position acquisition unit which acquires an actual position of the driven body; a position reference drive control unit which generates a position reference drive signal so as to bring the position nearer the target position; a counterforce acquisition unit which acquires a counterforce being received by the driven body; a counterforce reference drive control unit which generates a counterforce reference drive signal so as to bring the counterforce nearer the target counterforce; and a drive signal selection unit which selects either one of the position reference drive signal and the counterforce reference drive signal; in which the position command calculation unit calculates the position command so that the target position becomes a second order or higher relationship relative to time, and the counterforce command calculation unit calculates the counterforce command so that a relationship between the target counterforce and the target position becomes substantially linear.

A monitoring device of a robot system including: a current sensor detecting a value of a current flowing through the servo motor; a current/torque converting the value of the current flowing through the servo motor which is detected by the current sensor into a torque value; a driving torque estimating section estimating at least a part of driving torque required to drive the servo motor; a differential torque calculating differential torque between the torque value obtained by conversion in the current/torque converting section and an estimated value of the driving torque; an external force converting the differential torque calculated by the differential torque calculating section into an external force applied to the robot; and a stop signal generating section which generates to stop the robot based on a value of the external force obtained by conversion in the external force converting section, and supplies the stop signal to the controller.

A monitoring device of a robot system includes: an external force detecting portion configured to detect external force acting on a robot; an area determining portion configured to determine whether or not a predetermined portion of the robot is located within a predetermined area; a force monitoring portion configured to detect collision of the robot based on a first monitoring criterion including at least monitoring of the external force acting on the robot, and when the area determining portion determines that the predetermined portion of the robot is not located within the predetermined area, detect the collision based on a second monitoring criterion not including the monitoring of the external force; and a stop signal generating portion configured to, when the force monitoring portion detects the collision, generate a stop signal of the robot 2 and supply the stop signal to the control device.

A monitoring device of a robot system includes: an external force detecting portion configured to detect external force acting on a robot; an area determining portion configured to determine whether or not a predetermined portion of the robot is located within a predetermined area; a force monitoring portion configured to detect collision of the robot based on a first monitoring criterion including at least monitoring of the external force acting on the robot, and when the area determining portion determines that the predetermined portion of the robot is not located within the predetermined area, detect the collision based on a second monitoring criterion not including the monitoring of the external force; and a stop signal generating portion configured to, when the force monitoring portion detects the collision, generate a stop signal of the robot 2 and supply the stop signal to the control device.

A monitoring device of a robot system including: a current sensor detecting a value of a current flowing through the servo motor; a current/torque converting the value of the current flowing through the servo motor which is detected by the current sensor into a torque value; a driving torque estimating section estimating at least a part of driving torque required to drive the servo motor; a differential torque calculating differential torque between the torque value obtained by conversion in the current/torque converting section and an estimated value of the driving torque; an external force converting the differential torque calculated by the differential torque calculating section into an external force applied to the robot; and a stop signal generating section which generates to stop the robot based on a value of the external force obtained by conversion in the external force converting section, and supplies the stop signal to the controller.

Motion control of a robot arm is performed via a reducer connected to a motor. A controller thereof includes a thrust control unit that generates motor position command value based on an input thrust command value, and a motor control unit that generates a current value based on the motor position command value. The motor control unit feeds back a motor position detected by a motor encoder, and the thrust control unit feeds back thrust detected by a thrust meter. The feedback from the motor control unit suppresses vibration phenomena at the reducer, and the feedback from the thrust control unit suppresses transmission error, thereby enabling motion control of the arm with rapidity and precision.

Motion control of a robot arm is performed via a reducer connected to a motor. A controller thereof includes a thrust control unit that generates motor position command value based on an input thrust command value, and a motor control unit that generates a current value based on the motor position command value. The motor control unit feeds back a motor position detected by a motor encoder, and the thrust control unit feeds back thrust detected by a thrust meter. The feedback from the motor control unit suppresses vibration phenomena at the reducer, and the feedback from the thrust control unit suppresses transmission error, thereby enabling motion control of the arm with rapidity and precision.