Rotor Posture Measurement of a Spherical Motor applying Pattern Matching of Magnetic Field

Abstract

　This paper proposes a rotor posturę measurement method applying pattern matching of magnetic field for a spherical motor driven by electro-magnetic forces. The proposed method estimates the relative position of a permanent magnet arranged on the rotor by pattern matching of the outputs of arrayed Hall sensors with their output patterns measured and stored beforehand. This study develops a program to measure the rotor poture by the proposed method. The applicability of the proposed method is confirmed from the results of rotor posture measurement experiments for the rotation around x, y, and z axes. The measurement performance is compared with the method studied in a previous study. The measurement accuracy increases for the rotation around z axis. However, there are still some problems to improve the measurement performance.