Study on Combination Method for Straightness Profile Measurement: —Combination Method for Non-Periodic Surface Profile—

Software datums that separate a surface profile from straightness error motion of a scanning sensor are well-known for the straightness profile measurement. Though sequential two point method is often used, it's not useful for many sampling points. When number of sampling point is increased, influence of error propagation of sequential two-point method is increased. In this paper, some combination methods, based on the average criteria, the generalized two-point method criteria and the least squares criteria, are discussed, assuming that a measured profile is a non-periodic function. Simulation results show that the combination method based on the least squares criteria is suitable as the combination of the some large sensor interval sequential methods.