ADVANCING PRECISION: PREDICTIVE MODELING TECHNIQUES FOR POSITIONING ERRORS IN BALL-SCREW SYSTEMS
Keywords:
Positioning error model; Error analysis; Ballscrew motion system; Transmission error; PredictionAbstract
In this paper, a rapid approach on predicting the positioning error with high precision and resolution through measuring the errors of transmission and power in ball-screw motion systems is proposed. The positioning error is considered as the superposition of the transmission error of screwnut pair and the power error of the motor. The influences on the positioning error of assembly deviation and the deformation of the screw are analyzed according to the space geometry. Given the periodic characteristics of Fourier series, the comprehensive functions can be predicted by fragments. Thus, the method for predicting positioning errors by measuring a few values of transmission errors of screw-nut and that of motor errors is presented. A micro ball-screw motion system is measured to validate the method in the case study. The transmission error of the screw-nut was fitted into linear and trigonometric functions, and the motor error is fitted into sinusoidal curves. The two expressions at the same initial phase are superposed to predict the positioning errors. The coincidence between the measured results of positioning errors and the predicting spline proves the validity and precision of the rapid approach.