Design of Electrohydraulic Servo Systems for Articulated Robot Arm Control

Abstract

Electrohydraulic servomechanisms are widely used for heavy duty articulated robot arm controls. The design of those servo systems should be carried out by considering the nonlinear characteristics of the arm constructions, the poor static rigidity and the low natural frequency of the hydraulic driving system, and the interaction among multiple link motions. We studied those problems for a robot arm with two links and propose the design principle and procedure for improving the dynamic characteristics and reducing the interaction effects. The compensation was done with pressure feedback and remarkable improvements were verified by experiments.