Static Error Free Tracking Control Based on Linear Quadratic Regulator of 3-DOF Parallel Manipulator with Redundant Actuation

Abstract

Parallel manipulators have advantages such as high stiffness, low moving inertia, high payload capability, and high accuracy. In this paper, the servo drive system of valve controlled asymmetrical hydraulic cylinder is designed for 4-SPS/S parallel manipulator with redundant actuator. A unified nonlinear model suitable for forward and inverse motion is deduced for the valve controlled asymmetrical cylinder system, and simplified from point of engineering application. The global linearized model is established by nonlinear state feedback transformation. The tracking controller with zero steady-state errors based on linear quadratic regulator is designed for the global linearized model. Simulation results show that tracking performance of the proposed controller is good.