A Finite-Time Control for a Pneumatic Cylinder Servo System Based on a Super-Twisting Extended State Observer

In this paper, a finite-time control is proposed based on an extended state observer (ESO) for a pneumatic cylinder servo system. First, an ESO is designed to estimate the friction and varying loads using a super-twisting algorithm. Then, a finite-time controller is designed using a power integrator technology to ensure stability and improve control performances of the pneumatic cylinder servo system. Furthermore, both the effectiveness of the proposed ESO and the finite-time convergence of the closed-loop system are accordingly proven. Finally, experimental results demonstrate that both the control precision and the response rapidity are improved by applying the developed techniques.