Suppression Of Positioning Vibration For Multi-axis Servo System

Multi-axis servo system has been widely used in the modern manufacturing industry,due to its superior performance,however,mechanical transmission between servo motors and actuators cannot be ascribed as ideal rigid body,and end vibration may occur.This is more obvious when under the multi-axis drive system,on one hand,positional accuracy may decrease when under point-to-point positioning,on the other hand,it will cause inevitable contouring error.Theref ore,the research of end vibration suppression of multi-axis servo system is of a great significance.Model of dual inertia multi-axis drive system is established in this paper to research end vibration suppression of multi-axis servo system,passive vibration strategy is adopted for vibration suppression,then cross coupling is adopted for trajectory distortion compensation,thus trajectory tracking ability of multi-axis drive system is enhanced.Theoretical analysis and mathematical modeling are conducted : first,model of multi-axis drive system is established;the relationship between tracking error and contouring error under multi-axis drive is analyzed,different from the aim of single axis drive system,elimination of contouring error cannot fully depe nd on the elimination of tracking error among different axes.Second,the vibration issue is analyzed,although coupling exists among movement tracks,but vibration frequency is relatively independent,therefore it provides ideas to solve vibration issue i n multi-axis drive system.According to the characteristic of vibration frequency: relatively independent from one to the other.In this paper,the elimination of remaining vibration is conducted with vibration suppression method in single axis drive syste m.Accordingly,effectiveness,robustness and parameter configuration of notch filter and input shaper are comparatively analyzed.Simulation and experiment verify the validity of single axis vibration method,but it proves that inevitable system delay will be introduced in with the adoption of vibration suppression strategy,in multi-axis drive system,due to the parameter inconsistency among different axes,this delay time can be different as well,this phenomenon introduces distortion to the trajectory track of multi-axis drive system and brings about extra contouring error.For extra contouring errors leaded by different delays,cross coupling control is adopted to compensate the trajectory distortion brought about by vibration suppression method under single axis drive system.Finally,by trajectory tracking performance of linear trajectory and arc trajectory,multi-axis drive system end vibration and trajectory estimation distortion under delay is approved on an X-Y motion platform,the proposed cross coupling control based end vibration suppression for multi-axis is validated.