An error separation technique for measuring straightness motion error of alinear slide

A novel measurement system for on-machine determination of the straightness motion error and profile of a precision linear slide for active error comp ensation (AEC) purposes has successfully been developed. The characteristic s of the proposed measurement method an: (i) the profile is determined unde r on-machine conditions requiring no pre-calibration; and (ii) a novel appr oach involving representation of the test section of the profile by one cyc le of a periodic function is facilitated by specially arranging three senso rs to form a stationary stage. In this paper, the principles and operation of the measurement method are presented. The approach of defining a periodi c function to deal with the problem of non-periodicity of a profile is then described. A preliminary analysis of the sensor measurement errors is also given. Finally, the measurement system consisting of three non-contact cap acitive sensors is built and evaluated experimentally on a laboratory lathe and good reproducibility of profile results is obtained.