Robot gripper control system using PVDF piezoelectric sensors

Abstract

A novel robot gripper control system is presented which uses PVDF piezoelectric sensors to actively damp exerted force. By using a low-input-resistance amplifier to sense the current developed by the PVDF sensor, an output proportional to the rate of change of the force exerted by the gripper is obtained. The signals from the PVDF sensor and a strain gauge force sensor are arranged in a proportional and derivative (PD) control system for the control of force. The control system was tested on an instrumented Rhino XR-1 manipulator hand. The capabilities of the control system are analyzed analytically, and verified experimentally. The results for this particular gripper indicate that as much as 900% improvement in force step response rise time, and 300% reduction in overshoot are possible by inclusion of the PVDF sensor.