A failure diagnosis device applicable to a mechanical device provided with a motor as a source to drive a motion axis, and configured to acquire a moving position of the motion axis and a disturbance torque value applied to the motion axis every predetermined period, and to diagnose that a failure is occurring when the disturbance torque value is larger than a failure determination threshold, includes a disturbance torque selector configured to calculate a change from a reference value of each of the acquired disturbance torque values, and to accumulate the disturbance torque values except each disturbance torque value having the change from the reference value equal to or larger than a predetermined threshold, and a failure diagnosis unit configured to diagnose a failure of the mechanical device by using the disturbance torque values accumulated by the disturbance torque selector.

According to one embodiment, a robot control device is used for a robot arm including a link and a motor for rotationally driving the link. The robot control device includes a derivation part. The derivation part derives a first estimated value including a variation of a rotation angle of the link and a second estimated value including a variation of a rotation angle of the motor, based on an angular velocity and a current reference value of the motor. Furthermore, the derivation part derives an external force generated to the robot arm, based on a difference between the first estimated value and the second estimated value.

A failure diagnosis device applicable to a mechanical device provided with. motors independent of One another as sources to drive motion axes, respectively, and configured to acquire a moving position of each motion axis and a disturbance torque value applied to the motion axis every predetermined period, and to diagnose a failure of the mechanical device, includes a failure diagnosis unit configured to diagnose the motion axis as a failure when the disturbance torque value is larger than a predetermined failure determination threshold, and a re-determination unit configured to conduct re-determination of the failure on the motion axis, which is diagnosed as the failure by the failure diagnosis unit, based on a previous maintenance record and a previous inspection result.

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.

A failure diagnosis device for a mechanical device provided with a motor as a source to drive a motion axis, and configured to acquire a moving position of the motion axis and a disturbance torque value applied to the motion axis every predetermined period, and to diagnose that a failure is occurring when the disturbance torque value is larger than a failure determination threshold, includes a maintenance effect determination unit configured to calculate a change in the disturbance torque value before and after conducting of a maintenance task when the maintenance task is conducted on the motion axis, and a failure diagnosis unit configured to re-set the failure determination threshold only when the change in the disturbance torque value is larger than a predetermined threshold.

The invention provides a control device comprising: an actual value obtaining part, obtaining a torque actual value and a velocity actual value, wherein the torque actual value represents a torque generated by the driving source and the velocity actual value represents a velocity of the motion body; an inferring part, which calculates an external force inferred value and a velocity inferred value every other operation period based on the torque actual value by using an operation formula of a predetermined model representing driving of the motion body, wherein the external force inferring value represents an external force generated by the control system; and an output part, evaluating a reliability of the external force inferred value based on the velocity inferred value calculated together if the inferring part calculates the external inferred value, and effectively outputting the external force inferred value when it is judged that there is a designated reliability.