| Popis: |
This paper presents a new model of the Pneumatic Hydraulic Combination Control (PHCC) position servo system, which is driven by Pulse-Width-Modulation (PWM). The model was built by applying nonlinear state averaging method into the control of PWM in pneumatic systems, which not only overcame discontinuity of on/off valves, but also changed discontinuous nonlinear and non-affine form into a control canonical nonlinear affine form. Then a sliding controller was designed according to traditional sliding mode controller designing of nonlinear and uncertain systems and the method of sliding mode surface designing. The controller was implemented on PHCC position servo system with fixed liquid throttled, the effectiveness of the proposed approach is validated by experimental tracking data, which shows the aspects on speediness of PHCC systems optimal. |
