Joint torque sensory feedback in the control of a PUMA manipulator

The design of a joint torque sensor for a PUMA 500 and its characteristics are described. Using this sensor, a joint torque servomechanism is designed and implemented. A model of the actuator-transmission-load system, including flexibility, is developed and verified using both time- and frequency-domain techniques. Compensators based on this model are designed and tested. Experimental results obtained from pure torque control and joint motion tracking are presented. These results demonstrate a significant reduction of the effective friction (97%) and a substantial improvement in fine motion control.<
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