Joint Design and Position Servo Control of Frog Inspired Robot Based on Pneumatic Muscle and Reset Spring

摘要

In this paper, a single degree of freedom joint is designed based on pneumatic muscle and reset spring. First of all, through the isobaric experiment, equal length experiment and equal tension experiment, we build a more accurate pneumatic muscle model. Then a three-order affine nonlinear mathematical model is established by studying the characteristics of the highspeed switching valve, the internal pressure changes of the pneumatic muscle, the energy formula of pneumatic muscle during charging and releasing gas and the dynamic formula of joint to describe the relationship between the input of the value of PWM and output of the joint angle. MATLAB S function is used for simulation, and the corresponding static and dynamic response is obtained through different input (PWM). At the same time, the influence of the three main factors is studied. Based on this model, the equivalent sliding mode control law is designed. We prove the stability, verify the static and dynamic control effect of the control law.