Research on variable gain feedforward trajectory control of pneumatic servo system

Dynamic error coefficients of pneumatic servo system is analyzed theoretically. The response lag of the pneumatic closed loop system is caused by the speed item of the input signal and the dynamic error coefficient of speed changes with the changes of speed of the input signal. According to the characteristics of pneumatic servo system, the method of variable gain velocity feed forward is put forth and the feed forward coefficient is calculated with the method of system identification. Ultimately, experiments are carried out on and the results show that variable gain velocity feed forward method can compensate phase delay of the closed loop system efficiently, obviously improving the trajectory tracking accuracy.±0.1mm under different amplitudes and frequencies.