An experimental five-sensor system for measuring straightness and yawing motion errors of a linear slide

Abstract

In this study, a measurement system consisting of five distance sensors is designed and built to on-machine determine the straightness and yawing motion errors of a linear slide. The procedure to implement the proposed error separation method [1] is first discussed. The method can separate the yawing motion error from the straightness motion without knowing the slide profile beforehand. The experimental set-up and the testing procedure are then described. To verify the capability of this measurement system, a series of computer simulation and measurement experiments are undertaken. Comparison of the results with those obtained by a laser interferometer is also made to evaluate the system performance. Two error sources, i.e. sensor gain error and sensor placement error, which cause measurement uncertainty, are also studied by computer simulations. Testing results confirm that the measurement system can be used to determine the straightness motion with accuracy down to 1 µm. Good reproducibility of the profile results is also obtained.