Abstract: A new three-dimension position measurement method for mechanical workpiece using micro inertial measurement unit is proposed. First, The measuring principle is introduced in detail. The coordinate transition, attitude matrix solution and position calculation are studied with corresponding mathematics model and algorithms presented. The experiments are carried out in principle by common gyros and accelerometers and the results of the experiments are presented. Meanwhile, the measurement errors of this method are analyzed. Its characteristics are pointed out compared with common strapdown navigation systems. Moreover, the corresponding error correction algorithms re presented respectively to the inertial sensors and the whole system. As a result, the ways to improve the measurement accuracy is also discussed. It is indicated through practice that this method processes the advantage of convenience, high speed and continuous measurement, which makes it very significative for the fast measurement of large workpieces and complex surfaces.

Key words: Error compensation, Inertia, Large workpiece, Position measurement, Strapdown inertial navigation