Vibration phase of two screen frames in ordinary flip-flow screen varies in accordance with the change of incoming materials, and phase difference between fixed screen frame and floating screen frame is difficult to maintain at ideal 180 degrees, which leads to low screening efficiency. In view of the above problems, mechanical model and vibration equation of double motor driven flip-flow screen were established, relationship of amplitude and phase between fixed and floating screen frames were obtained, and it was concluded that when speed of double excitation motor was synchronized and phase difference of eccentric block is 170°, vibration phase difference of double screen frames can achieve 180°. Servo control system of double motor driven flip-flow screen was proposed, and cross-coupling-based speed synchronization control method and improved Bang-Bang-based phase compensation control algorithm were used. The simulation results show that the system follows quickly in startup phase with short adjustment time and small overshoot, ideal speed synchronization ; rotation speed and phase compensation speed are fast, absolute value of speed fluctuation amplitude is about 70 r/min, and eccentric block phase difference fluctuation amplitude is controlled within 5°, which verifies the system has strong anti-interference performance.
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