Improving the Dynamic Behavior of a Servodriven Electro-hydraulic Robotic Manipulator

The authors detail two servo-control strategies which improve the performance of servodriven electro-hydraulic robotic manipulators. The first servo-controller is pragmatic approach based on both empirical controller design and fuzzy logic and results presented demonstrate that its performance clearly surpasses that of the conventional P-controller. The second servo-controller is a robust state-space controller designed by applying the Ackermann parameter space method. This controller uses both the measured angular position and acceleration as state-variables to directly control the angular position of the revolute joints. In order to determine the angular acceleration, a contact-free acceleration sensor based on the Ferraris principle has been developed and described in detail. Results are presented which clearly demonstrate the improvement of the servo-control quality through use of the acceleration sensor.