Contour error pre-compensation for five-axis high speed machining: offline gain adjustment approach

This paper presents an offline gain adjustment (OGA) approach to reduce contour error in five-axis high speed machining. The proposed contour error formulation is based on the estimation of tool contact points and the OGA is inspired from the idea of model predictive control (MPC). The control gains used in the position loop of servo drives are optimally adjusted offline to reduce the contour error for the considered trajectory. The obtained gain profiles are computed preserving axis kinematic limitations, stability criterion of servo drives, and the motor current constraints. The OGA is developed thanks to a validated machine simulator. The simulation results prove that the OGA reduces significantly the contour error in five-axis high speed machining.