Discrete-time Adaptive Control of Pneumatic Actuators for 6-DoF Stewart Platform

Abstract

This paper deals with computer-controlled pneumatic actuators for the Gough-Stewart platform with 6 degrees of freedom. An important feature considered in the paper pneumatic actuator is the use of a group of valves rather than a spool valve to control the pressure in the chambers, which leads to a significant quantization in terms of the level of the control action. In addition, there is a sampling in time in the control loop. The present work is aimed at ensuring the robustness of the pneumatic actuators for the Stewart platforms concerning their parameters and the effect of changing the load on the drive caused by the interdependence of the drives due to the movement of the platform. Two discrete-time (parametric, and signal-parametric) adaptive control algorithms, based on the concept of an implicit reference model with anti-windup correction are proposed. The simulation results are presented, demonstrating the efficiency of the signal-parametric algorithm.