Dynamic characteristics of pneumatic side-sway joint

Because of shortcomings of the existing pneumatic joints, side-sway joint driven by FPAs directly was proposed which could simulate swing movement of human hand. The operating principle of the side-sway joint finger was presented. According to the first law of thermodynamics, combined with dynamic equation of the joint, the dynamic model of the side-sway joint was established. Experiments were carried out to test the static and dynamic characteristics of the joint. There was certain error between experimental curve and theoretical?curve, and the error cause was analyzed. Using a series dual loop control method, the output angle and output force of joint were controlled. The results showed: when expected output angle was15°, the loop dynamic response time was about 0.3 s, and the steady-state relative deviation was less than 0.65%. When expected output force was 188 N·mm, the loop dynamic response time was about 0.3?s, and the steady-state relative deviation was less than 1.5%. The side-sway joint can meet the requirement for designing multi-fingered dexterous hand joint.