Process and system for monitoring backlash in a gear of a joint of an industrial robot
AssigneeComau S.p.A.
InventorsEliana Giovannitti, Nicola Campagna
Life of this patent
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Abstract
A process for monitoring backlash in a gear of a joint of an industrial robot, wherein said joint includes a first joint body and a second joint body coupled together with the possibility of moving with respect to one other, a motor provided with an encoder, and a motion-transmission assembly designed to transmit the torque generated by said motor to said second joint body to bring about a movement of said second joint body with respect to said first joint body, said transmission assembly comprising said gear. The process is characterized in that the signal of the encoder of the motor for driving the joint is used without providing any additional sensor specifically dedicated to monitoring of the backlash.
Claims14
A process for monitoring backlash in a gear of a joint of an industrial robot, wherein said joint comprises:
- a first joint body and a second joint body movably coupled together, a motor provided with an encoder, and a motion-transmission assembly operable to transmit a torque generated by said motor to said second joint body to bring about a movement of said second joint body with respect to said first joint body, said motion-transmission assembly comprising said gear,
- said process comprising the steps of:
- driving via said motor a movement of said second joint body with respect to said first joint body;
- during said movement, acquiring a signal of said encoder;
- receiving a characteristic oscillation curve;
- processing said encoder signal for identifying an oscillation curve in said encoder signal, corresponding to said characteristic oscillation curve;
- determining a parameter of the oscillation curve identified, indicating an amplitude of oscillation;
- and
- determining a condition of backlash on the basis of said parameter determined.
A system for monitoring backlash in a gear of a joint of an industrial robot, comprising:
- the industrial robot comprising at least said joint, wherein said joint comprises a first joint body and a second joint body movably coupled together, a motor provided with an encoder, a motion-transmission assembly operable to transmit a torque generated by said motor to said second joint body to bring about a movement of said second joint body with respect to said first joint body, said transmission assembly comprising said gear,
- a control unit for driving said motor according to a test mode in order to monitor the backlash of said gear;
- and
- a processing unit configured for:
- receiving, one of directly or through said control unit, a signal of said encoder regarding a step of driving of said motor in said test mode;
- receiving a characteristic oscillation curve;
- processing said encoder signal for identifying an oscillation curve in said encoder signal, corresponding to said characteristic oscillation curve;
- determining a parameter of the oscillation curve identified, which indicates an amplitude of oscillation;
- and
- determining a condition of backlash on the basis of said parameter determined.
Dependencies are inferred from the claim text.