Simulation on friction compensation for the pneumatic proportional system

The friction mechanism of the valve-controlled cylinder system and its adverse effects on the system control performance are analyzed. And a new compensating method for reducing the friction of the system is presented. First, the valve friction that is the main cause of the proportional valve deadband is analyzed and simulated by use of the neural network control (NNC). And the pneumatic cylinder friction is simulated and compensated by adding the vibrating signal to the control signal. Then, the valve-controlled cylinder system is simulated by use of two compensation methods. Finally, the system experiment is carried out and its results prove that the buffer time of the system is shorted and the stability and position accuracy of the system is improved by use of the compensation method. The presented compensation method shows high engineering value.