The invention relates to a decoupling control method for a flexible
ball screw system of a
machine tool, and the method comprises the steps: firstly carrying out the structural decoupling of a speed inner ring
transfer function, and obtaining a flexible
modal term in the
system; designing a shaping controller based on the flexible
modal item, wherein the parameters of the shaping controller are only determined by the anti-
resonance frequency and the anti-
resonance damping ratio of the
system; a
closed loop of a speed
inner loop is dynamically shaped into a target second-
order system, so that
resonance suppression and bandwidth adjustment are independently realized through a PI controller. On the basis, structural decoupling is carried out on a position outer ring
transfer function, a high-order flexible mode first-order component is separated, an additional controller based on position difference feedback is designed, the feedback
gain of the additional controller and the proportional
gain of a P controller in a position outer ring are equal in size and opposite in sign, and the influence of the high-order flexible mode first-order component is restrained. According to the method, decoupling of parameter setting of the shaping controller and the P-PI controller is achieved, the parameter setting process is simplified, and the closed-
loop bandwidth and industrial practicability of the flexible
ball screw feeding system are improved.