Position Control of a Triple-Joint Pneumatic Finger With Angle Sensors Utilizing a Tendon-Driven Technique

In this article, a position control strategy is proposed for a triple-joint pneumatic finger with angle sensors using a tendon-driven technique. Measurement noise from the angle sensors is reduced by a Kalman filter to optimize output angle values of the triple-joint pneumatic finger. A nonlinear extended state observer (ESO) is designed based on a segmentation function to estimate nonlinear friction from tendon transmission. The integral backstepping controller is used to improve convergence time and control precision for the triple-joint pneumatic finger. Stability analyses of the nonlinear ESO and the integral backstepping controller are demonstrated by Lyapunov methods. Experiments results are given to illustrate effectiveness of the position control strategy for the triple-joint pneumatic finger.