Research On The Control Method Of Pneumatic Artificial Muscle Drive

As robotics becomes more advanced in various fields,the demands on the drives of robots are also increasing.Pneumatic artificial muscles have received widespread attention from researchers all over the world because of their light mass and small size,as well as their safety and flexibility,and their ability to generate large actuation forces.This project takes Festo's pneumatic artificial muscle as the research object,introduces the common models of pneumatic artificial muscle,namely the static model based on the analytical method and the three-element model based on the phenomenon,and designs experiments to identify the parameters of the three-element model,then designs the controller according to the model,verifies the control performance of the controller through simulation and experiments,and extends the control method to the joint,then the joint Simulations and experiments are carried out to analyse the tracking performance of the controller for the desired signal.Firstly,based on the discussion of the structure and working principle of pneumatic artificial muscles,two common models of pneumatic artificial muscles are introduced,an analytical method mathematical model based on the law of energy conservation and a threeelement mathematical model based on phenomena,it consists of a spring unit,a damping unit and a contraction unit in parallel,followed by designing experiments to identify the parameters of the three-element model.Secondly,we design the sliding mode controller,backstepping sliding mode controller and adaptive backstepping sliding mode controller by combining the identified three-element model of pneumatic artificial muscle,and conduct simulation experiments,and select the sliding mode control and adaptive backstepping sliding mode control methods for pneumatic artificial muscle according to the simulation results.The experimental platform is built and the tracking experiments are designed for step signal and sinusoidal signal.The experimental results show that the adaptive backstepping sliding mode control has better trajectory tracking effect.Finally,the mathematical model of the antagonistic pneumatic artificial muscle-driven joint is derived by combining the identified three-element model and the single-joint dynamics model,and the sliding-mode controller and the adaptive backstepping sliding-mode controller are designed for the model,and the two controllers are simulated in Matlab/Simulink and control experiments are conducted.The results show that the adaptive backstepping sliding mode controller has a better effect on the angle tracking of the joint.This paper focuses on the control method of pneumatic artificial muscles,solves the problem of low control accuracy of pneumatic artificial muscles and their constituent antagonistic joints,and provides a referenceable control method for the research of pneumatic artificial muscle-driven multi-joint robotic arm.