Practical controller design for ultra-precision positioning of stages with a pneumatic artificial muscle actuator

International Technical Postgraduate Conference

Tang, T.F.^1 ; Chong, S.H.^1

Centre for Robotics and Industrial Automation, Faculty of Electrical Engineering, Universiti Teknikal Malaysia Melaka, Hang Tuah Jaya, Durian Tunggal, Melaka

76100, Malaysia^1

关键词: Acceleration feedback;    Controller design method;    Damping characteristics;    Nominal characteristic trajectory following;    Nonlinear characteristics;    Pneumatic artificial muscle;    Positioning performance;    Ultra-precision positioning;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/210/1/012056/pdf
DOI  :  10.1088/1757-899X/210/1/012056

来源: IOP

【 摘 要 】

This paper presents a practical controller design method for ultra-precision positioning of pneumatic artificial muscle actuator stages. Pneumatic artificial muscle (PAM) actuators are safe to use and have numerous advantages which have brought these actuators to wide applications. However, PAM exhibits strong non-linear characteristics, and these limitations lead to low controllability and limit its application. In practice, the non-linear characteristics of PAM mechanism are difficult to be precisely modeled, and time consuming to model them accurately. The purpose of the present study is to clarify a practical controller design method that emphasizes a simple design procedure that does not acquire plants parameters modeling, and yet is able to demonstrate ultra-precision positioning performance for a PAM driven stage. The practical control approach adopts continuous motion nominal characteristic trajectory following (CM NCTF) control as the feedback controller. The constructed PAM driven stage is in low damping characteristic and causes severe residual vibration that deteriorates motion accuracy of the system. Therefore, the idea to increase the damping characteristic by having an acceleration feedback compensation to the plant has been proposed. The effectiveness of the proposed controller was verified experimentally and compared with a classical PI controller in point-to-point motion. The experiment results proved that the CM NCTF controller demonstrates better positioning performance in smaller motion error than the PI controller. Overall, the CM NCTF controller has successfully to reduce motion error to 3μm, which is 88.7% smaller than the PI controller.