Static model of pneumatic flexible rotary joint

Service robot, bionic robot and agricultural robot must directly contact with organism, which requires high security and adaptability. Flexible pneumatic actuators and joints can meet this demand. A type of flexible pneumatic rotary joint is proposed in this paper, based on the flexible pneumatic actuator FPA. The rotation movement is realized by inflating and deflating the rotary joint chamber. According to the principle of equilibrium of moments, the static model of rotary joint are established. Impact of the parameters initial angle, average radius and shell thickness on the output angle of rotary joint is simulated with MATLAB. The experimental results are basically consistent with that of simulation, which implies the validity of rotary joint static model.