Analysis and measurement of wobble error on simulation turntable

A 3-DOF simulation turntable with wobble errors is introduced. The characteristics of period and variation in the wobble error are liable to bring about orientation error, which is a function of the overall static inaccuracy. Aimed to compensate orientation error, a wobble error calibration is proposed to measure the wobble error between the axis and the bushing of a rotating axis in simulation turntable. The proposed method can be implemented in two steps. In the first step, based on transformation matrix and small angle approximation, gesture transformation relation with various error items is achieved, and a set of possible measure results is generated by autocollimation. In the second step, error separation equations, which are composed of wobble errors and mirror mounting errors, are used to obtain one harmonic error from the results. Based on Bezier formula, the uncertainty of the wobble error can be obtained in the expectation and variance of individual errors. The analysis result is proved to be correct through experiment