Accuracy improvement of three-axis CNC machining centers by quasi-static error compensation

This paper discusses the development of a general quasistatic error model for multiaxis CNC machining centers using rigid body kinematics. To predict the quasi-static errors at any point in the workspace, a new method was proposed using the meshing concepts developed in the finite element method literature. Taking the nonlinearity of quasi-static errors into account, computational approaches to compensating errors of the basic motions of a CNC machine are developed. The strategies developed are tested on a CNC machine, and the results show that a 80-90% reduction of quasi-static errors is gained after introducing compensation.