A novel dynamic contour error estimation and control in high-speed CNC

High-speed CNC machining requires high-precision servo response and dynamic performance of feed drives with better control parameters matched in coupled axis. In this paper, an electromechanical coupling system of multi-axis CNC machine tool feed drive model is established for servo parameter optimization and high-precision contour error improvement. The influences of the joint stiffness and the friction disturbance in servo dynamic have been considered. The disturbance parameter and joint stiffness have been identified by unbiased least squares scheme. The electromechanical coupling model is used to study the contour error estimation and compensation technology in high-speed machining. The multi-axis contour error is estimated by using Ferguson curve to approximate the curve between the interpolation points. The calculation is fast and accurate enough for contour error pre-compensation. Experiments prove that five-axis contour error can be effectively reduced by dynamics pre-compensation in high-speed CNC with better processing quality and stability improvement.