Mechanism and impedance control of pneumatic muscle with shape memory alloy braided sleeve

Pneumatic muscle(PM) is the research focus of bionic robot.Therefore,the fiber knitted sleeve of PM is replaced with shape memory alloy(SMA) and the mechanism is designed.Through equivalent translation to deformable cylinder,static driving force model is established.Through equivalent analysis of contraction,damping and elastic element of PM,dynamics driving force model is derived.An impedance control scheme with inner position PID loop is designed for active compliant in Cartesian space.And impedance adjustment target is built based on damping-spring model.By Laplase transform and frequency domain analysis,stable condition of impedance control is given.On Matlab,the control simulations of varying impedance parameters are done to analyzing impact of parameters to compliant character.Simulation results show that generalized rigid is the main impact factor of contact force,and impedance control proposed can achieve harmony complain of force and position.