Abstract: To counter the defects of the normal pneumatic servo system, a new kind of compound medium transmission of gas and liquid – the pneumatic hydraulic combination control (PHCC) system is put forward, which is based on the traditional pneumo-hydraulic system and the liquid medium is led into the pneumatic servo system and controlled in close-loop. In this system, the dynamic characteristics are changed by means of regulating the damping force of the liquid and some special functions are realized. The conclusion is that the PHCC servo system can realize high rigidity, high precision and high frequency response, which the normal pneumatic servo system is difficult to perform. It is significant of developing the pneumatic technique.

Key words: Pneumatic servo system, Pneumatic-hydraulic combination control, Pneumo-hydraulic system, Lateral force model, Lunar roving vehicle, Terramechanics, Wheel with deformable property and mesh surface