Adaptive Tuning of Sliding Mode-PID Control in Free Floating Space Manipulator by Sliding Cloud Theory

B Kharabian

doi:10.11648/j.ajmie.20170202.12

Abstract

In this paper, a combinational control approach of sliding mode-PID is utilized in free floating space manipulator. Due to float base, nonlinearity of free floating space manipulator dynamics lead to having unstable behaviour and complicated dynamic model. To simplify the dynamic equation, dynamically equivalent manipulator is utilized which is a fixed base manipulator. In this approach, an unique map transfers dynamic parameters of free floating space manipulator to a fixed base manipulator. This transfer enlarges uncertainty bound of parameters. Hence, sliding mode-PID control as a combinational robust control approach is applied in the system. In this case, PID like sliding surface is proposed instead of conventional sliding surface. Adaptive tuning of sliding surface provides a Sliding Cloud that is a kind of dynamic sliding surface. In this way, inclination of system to stable behaviour increases and robustness of system, in the presence of uncertainties, is bolstered.

Highlights

Space manipulators have significant role in space crafts and perform some services such as maintenance and repair [1]
On the one hand control law propels dynamics of system to sliding surface, and on the other hand, Sliding Cloud moves onto the dynamics
A 2 DOF space manipulator with free base is considered as system

Summary

Introduction

Space manipulators have significant role in space crafts and perform some services such as maintenance and repair [1]. Parlaktuno and Ozkan [5] applied an adaptive control method to space manipulator using DEM model. In this approach, unknown parameters such as mass and inertia tensor parameters are estimated by adaptive methods. In order to achieve perfect performance in the system, adaptive tuning of PID like sliding surface is posed that creates a Sliding Cloud. B. Kharabian et al.: Adaptive Tuning of Sliding Mode-PID Control in Free Floating Space. On the one hand control law propels dynamics of system to sliding surface, and on the other hand, Sliding Cloud moves onto the dynamics As a result, this method renders a reinforced tendency to stability situation.

Dynamic of Free Floating Space Manipulator

Sliding Mode-Pid Control

Adaptive Sliding Mode-PID Control

Simulation Results

Conclusion