Original Research ARTICLE
Robust Trajectory Tracking Control for Variable Stiffness Actuators With Model Perturbations
- 1Wuhan University, China
- 2National University of Singapore, Singapore
Variable Stiffness Actuators (VSAs) have been introduced to develop new-generation compliant robots. However, the control of VSAs is still challenging because of model perturbations such as parametric uncertainties and external disturbances. This paper proposed a nonlinear disturbance observer (NDOB)-based composite control approach to control both stiffness and position of VSAs under model perturbations. Compared with existing nonlinear control approaches for VSAs, the distinctive features of the proposed approach include: 1) A novel modeling method is applied to analysis the VSA dynamics under complex perturbations produced by parameter uncertainties, external disturbances, and flexible deflection; 2) A novel composite controller integrated feedback linearization with NDOB is developed to increase tracking accuracy and robustness against uncertainties. Both simulations and experiments have verified the effectiveness of the proposed method on VSAs.
Keywords: variable stiffness actuator (VSA), nonlinear disturbance observer (NDOB), Compliant actuator, Feedback linearization, robust control
Received: 13 Mar 2019;
Accepted: 17 May 2019.
Edited by:Hong Qiao, University of Chinese Academy of Sciences, China
Copyright: © 2019 Guo, Sun, Ling, Pan and Xiao. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
Dr. Jie Ling, Wuhan University, Wuhan, Hubei Province, China, email@example.com
Dr. Yongping Pan, National University of Singapore, Singapore, 119077, Singapore, firstname.lastname@example.org