5-Axis feed drive modelling and spatial contour error analysis based on dynamics of servo system

摘要

This paper presents a model of 5-axis feed drive system combined with both the electronic controller and mechanical transmission of each axis. The Stribeck friction model is applied as the disturbance of the system with feedforward PID controller. An S-curve is performed using a model of 5-axis machine tool based on 5-axis interpolation and coordinate transformation. The feed drive system is improved by velocity feed forward compensation and full closed-loop control for error elimination. Spatial contour error in term of the accumulation of lag distance for each axis is measured. Due to the influence of friction motion generate tracking error around zero velocity. The results shows that the lag distance have greater reduction between applied with and without full closed-loop control and feed forward compensation. The decrease of the tracking error leads to better contour error and space error achieving high performance and precise control in 5 axis machining.