Enhanced compensation control of pneumatic muscle actuator with high-order modified dynamic model. (January 2023)

• Record Type: Journal Article
• Authors: Zuo, Jie; Liu, Quan; Meng, Wei; Ai, Qingsong; Xie, Sheng Q.
• Is Part Of: ISA transactions. Volume 132(2023)
• Page Start: 444
• Page End: 461
• Publication Date: 2023-01
• Subjects: Dynamic model -- Compensation control -- Dynamic external loads -- Pneumatic muscle -- Soft actuator; Engineering instruments -- Periodicals; Engineering instruments; Periodicals; Electronic journals; 629.805
• DOI: 10.1016/j.isatra.2022.06.012
• Languages: English
• ISSNs: 0019-0578

Abstract

Abstract: Dynamic behaviour of the pneumatic muscle actuator (PMA) is conventionally modelled as a pressure-based first-order equation under discrete loads, which cannot exactly describe its dynamic features. Considering PMA's nonlinear, time-varying and hysteresis characteristics, we propose a novel high-order modified dynamic model of PMA based on its physical properties and working principle, with coefficients being identified under external dynamic loads. To tackle PMA's nonlinear hysteresis problem in high-frequency movements, a global fast terminal sliding mode controller with the modified model-based radial basis function (RBF) neural network disturbance compensator (RBF-GFTSMC) is designed. Comparison experimental studies are carried on a designed PMA platform that can provide continuously changing loads. Results show that the RBF-GFTSMC has superior trajectory tracking performance and disturbance compensation capability under wide-ranged frequencies and external loads, which can be potentially used to achieve precise control of PMA-actuated robots. Highlights: Modified model better describes pneumatic artificial muscle's dynamic behaviour. Modelling under continuously changing and dynamic load conditions. Novel controller adapts to high frequency applications with human interaction. Model-based compensator improves control performance with dynamic external loads.