Approximate Feedback Linearization Control for Spatial 6-DOF Hydraulic Parallel Manipulator

Chifu Yang*, 1, 2, Shutao Zheng2, O. Ogbobe Peter2, Qitao Huang2, Junwei Han2
1 State Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin 150001, China
2 School of Mechanical and Electrical Engineering, Harbin Institute of Technology, Harbin 150001, China

© 2010 Yang et al

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: ( This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

* Address correspondence to this author at the Building 2F, Room 325, Science Park of Harbin Institute of Technology, No.2 Yi-kuang Street, Nangang District, Harbin 150001, China; Tel: +86-451-86402642-325 (Office), +86-15045107623 (Mobile); Fax: +86-451-86412558; E-mail:


Traditional feedback linearization approach (TFL) requires a priori knowledge of plant, which is difficult and the computational efficiency of controller is low due to the complex dynamics of spatial 6-DOF hydraulic parallel manipulator. In order to improve the tracking performance of spatial 6-DOF hydraulic parallel manipulator and to conquer the drawbacks of TFL, a novel approximate feedback linearization approach, non-model based method, is proposed in this paper. The mathematical model of spatial hydraulic parallel manipulator is established. The approximate feedback linearization control is designed for the parallel manipulator in joint space, with position and stored force in the previous time step are employed, as a learning tool to yield improved performance. Under Lyapunov theorems, the stability of the presented algorithm is confirmed in the presence of uncertainties. Simulation results show the proposed control is easy and effective to realize path tracking, and it exhibits excellent performance and high efficiency without a precision dynamics of plant. Furthermore, the presented algorithm is well suitable for most industrial applications.

Keywords: Parallel manipulator, hydraulic system, approximate feedback linearization, path tracking.