Second-order adaptive discrete-time fast terminal sliding mode control of a DEAP actuator with hysteresis nonlinearity

Abstract

This paper investigates trajectory tracking control of a dielectric electro-active polymers (DEAP) actuator with hysteresis nonlinearity by using second-order adaptive discrete-time fast terminal sliding mode control (2-ADFTSMC) scheme. Taking into account that the hysteresis behaviour is asymmetric rate-dependent, a Hammerstein model is established to represent the DEAP actuator. Then, based on a novel 2-ADFTSM function and a terminal-sliding-mode-type switching control law, a 2-ADFTSMC scheme is proposed to improve the trajectory tracking performance. Furthermore, the stability of the closed-loop system is proved. Compared with discrete-time sliding mode control (DSMC) and discrete-time fast terminal sliding mode control (DFTSMC) schemes, the proposed control scheme can provide higher tracking accuracy, faster convergence speed, and stronger robustness in presence of model uncertainties and external disturbances. The effectiveness and practicality of the proposed control scheme are validated through the experiments on the DEAP actuator.

Keywords:

• Dielectric electro-active polymers
• trajectory tracking control
• hysteresis nonlinearity
• Hammerstein model
• adaptive discrete-time fast terminal sliding mode control

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This paper is supported by the National Natural Science Foundation of China [Grant Numbers 61472037, 61433003].

Notes on contributors

Mengmeng Li

Mengmeng Li received the B.S. degree from Anyang Normal University, Anyang, China, in 2014, and the M.S. degree from Capital Normal University, Beijing, China, in 2017. She is currently working toward a Ph.D. degree in the School of Automation, Beijing Institute of Technology, Beijing, China. Her research interests include sliding mode control, fuzzy control, optimal control, and adaptive dynamic programming.

Yuan Li

Yuan Li Associate Professor with school of Automation, Beijing Institute of Technology. He received his Ph. D. degree from Institute of Automation, Chinese Academy of Sciences, Beijing, China, in 2006. He is a member of Youth Academic committee, Chinese Association of Automation. He authored more than 50 papers, and published 2 books. His current research interest covers robot visual control, visual measurement and perception, intelligent control.

Qinglin Wang

Qinglin Wang Professor with School of Automation, Beijing Institute of Technology. He received his Ph. D. degree from Institute of Automation, Chinese Academy of Sciences, Beijing, China, in 1998. He authored of more than 100 papers and articles. He proposed the Dynamic Equilibrium State theory in 1998. His current research interest covers complex systems modelling, optimization, control, simulation and decision-making.