Non-singular Terminal Sliding Mode Control for Pneumatic System Based on Extended State Observer

To suppress the compound disturbance of internal parameter perturbation and external disturbance of pneumatic system, a non-singular terminal sliding mode control (NTSMC) based on extended state observer (ESO) is proposed in this paper. Firstly, the pneumatic system model is established and the tracking differentiator is designed to obtain differential signals. Secondly, the NTSMC controller is used to effectively suppress compound disturbances in pneumatic system. By designing sliding mode variable structure ESO, the buffeting problem of sliding mode is suppressed. The combined perturbation estimated by ESO is used as the control rate calibration basis, which could effectively suppress buffeting. Finally, the simulation illustrates that the NTSMC-ESO controller has stronger disturbance suppression ability and better position control performance for pneumatic system than NTSMC and PID.