Adaptive Variable-frequency PWM Control Algorithm for Low Action Count High-speed On-off Valve Pneumatic System
The single-chamber,two-valve pneumatic pressure servo system features fast response,high reliability,and low cost,and has important applications in areas such as pressure stabilization of automotive brakes and pneumatic clamping devices.To reduce the number of switching times and prolong the service life under the premise of meeting the control requirements,an adaptive variable-frequency PWM control strategy is proposed.A frequency regulation factor is introduced to design an adaptive frequency adjustment function,which can give the optimal PWM base frequency according to the tracking error and its rate of change size to achieve a low-frequency response when the system has a large tracking error,and high-frequency accurate operation when the tracking error is small,thus reducing the number of switching times of high-speed on-off valve.The experimental results show that the variable-frequency PWM strategy minimizes the number of inlet valve switching times by 45％ for the step signal and 23％ for the harmonic signal compared with the traditional fixed-frequency PWM.
万方数据
维普
