Development of a three-dimensional contouring measuring system and error compensation method for a CNC machine tool

Abstract

The traditional method of dynamic performance inspection for a machine tool is to use a double ball bar (DBB) and grid encoder for contouring tests. With the increasing demand for miniaturization and fast machining in industry. DBB has an inadequate dynamic performance for inspection in conditions that have a small working range, high speed, 3D measurement, and so on. The present paper describes the development of a high-speed dynamic performance measurement system with position-sensitive detectors (PSDs). It consists of two PSDs and two laser diodes. After calibration and actual measurement, the system was verified to be competent for measuring the static and dynamic error of the linear axis in one, two, or three dimensions with a system resolution of 0.5 μm and a repeatability of 1 μm. The current paper focuses on measuring the machine tool controller performance in three-dimensional (3D) high-speed motion. When the machine tool moves with high-speed, machining errors can easily occur on the workpiece; 3D error compensation methods are put forward in this paper to solve this problem. The methods were verified as significantly decreasing the contouring error.