Two-layer sliding mode control of pneumatic position synchro system with feedback linearization based on friction compensation

Pneumatic systems have been widely used in industrial applications because of their well-known advantages. However, pneumatic systems have disadvantages that include strong non-linearity and low natural frequency. These drawbacks make it difficult to obtain satisfactory control performances in comparison to hydraulic systems. In this paper, the fundamental characteristics and nonlinear control strategy of the pneumatic system is studied. The two-layer sliding mode synchro system with feedback linearization based on friction compensation is applied to electro-pneumatic synchro position system. To verify the used strategies, experiments with the synchro system are performed. The experimental results show that the new designed controller is effective for both accuracy and robustness.