Enhanced-PID Control Based Antagonistic Control For Pneumatic Artificial Muscle Actuators

• Main Author: Tan, Ming Hui
• Format: Thesis
• Language: English; English
• Published: 2016
• Subjects: T Technology (General); TJ Mechanical engineering and machinery
• Online Access: http://eprints.utem.edu.my/id/eprint/18364/1/Enhanced-PID%20Control%20Based%20Antagonistic%20Control%20For%20Pneumatic%20Artificial%20Muscle%20Actuators.pdf; http://eprints.utem.edu.my/id/eprint/18364/2/Enhanced-PID%20Control%20Based%20Antagonistic%20Control%20For%20Pneumatic%20Artificial%20Muscle%20Actuators.pdf; http://eprints.utem.edu.my/id/eprint/18364/; https://plh.utem.edu.my/cgi-bin/koha/opac-detail.pl?biblionumber=100187

Pneumatic artificial muscle (PAM) is a rubber tube clothed with a sleeve made of twisted fiber-code, and is fixed at both ends by fixture. It has a property like a spring, which enables it to change its own compliance by the inner air pressure. The advantages of pneumatic system such as high power-to-weight ratio, compactness, ease of maintenance, inherent safety and cleanliness led to the development of McKibben muscle and PAM actuators. However, the drawbacks of PAM, for example, the air compressibility and the lack of damping ability of PAM bring dynamic delay to the pressure response and cause oscillatory motion to occur. It is not easy to realize the PAM motion with high accuracy and high speed due to all the non-linear characteristics of pneumatic mechanism. In this thesis, an antagonistic-based PAM system is designed and presented. Two identical PAM actuators are connected in parallel and vertical direction which imitate the human biceps-triceps system and emphasize the analogy between the artificial muscle and human skeletal muscle behavior. Some past control algorithms on the positioning control of PAM mechanisms are discussed. In this thesis, a practical control method, namely enhanced-PID controller is proposed to control the trajectory motion of the PAM actuators. The development and modeling of the experiment setup are explained, followed by the driving characteristics of the PAM system. Two simple and straight forward steps are demonstrated as the design procedures of the enhanced-PID controller. The control structure of the proposed controller consists of a PID element, Compensator A and Compensator B. The effectiveness of the proposed control algorithm is validated in sinusoidal continuous motion. The tracking performance of the enhanced-PID controller is compared with a classic PID controller, showing that the control performance of the enhanced-PID controller is satisfactory and better in dealing with highly non-linear PAM system.