数控机床高速高加速进给下的跟随误差控制策略

A comprehensive control strategy that integrates modal filter controller and zero phase tracking controller is proposed to solve the problem that when numerical control (NC) machine tools work at high speed with high feeding speed and acceleration of each axis, it is difficult to control the tracking error and guarantee machining accuracy. The principle of zero pole cancellation is firstly used to obtain a mode filter controller set in the velocity loop, which cancels the first-and second-order torsional vibration modes of the ball-screw feed system, removes the limitations of the two modes on the servo bandwidth and continuously increase the servo bandwidth. Then, the zero phase tracking controller set before the position loop is obtained and the phase lag of the servo feed system is improved by approximating the inverse of the transfer function of the whole servo feed system. Finally, the control of tracking errors of NC machine tools at high speed and acceleration feeding is realized. Simulation results and a comparison with the traditional PID control strategy show that when the feed speed is 30 m/min and the acceleration is 10 m/s ² , the proposed integrated control strategy reduces the tracking error to less than 0.1% of the original one.