Improving attitude detection performance for spherical motors using a MEMS inertial measurement sensor

Abstract

A spherical motor has multiple degrees of freedom. Its motion control requires an accurate attitude detection system. This study proposes a low-cost microelectromechanical system (MEMS) inertial measurement sensor to detect the attitude of the spherical motor. The proposed sensor combines a three-axis gyroscope and a three-axis accelerometer to obtain raw position data of spherical motors to estimate rotor's attitude. To improve the accuracy of the estimated attitude from the raw position data, the authors reduce the inclination angle error between the motor's rotor and MEMS sensor's coordinate systems by compensating axial angle error. A high-speed camera that generally provides high accuracy of the attitude is used as a calibration device for comparison and validation. Experimental results show that the MEMS inertial measurement sensor can achieve accurate attitude estimation that is suitable for motion control of a spherical motor.