Research of orientation detection method for spherical motor and effect on PD control system based on machine vision

The rotor orientation detection of spherical motor is crucial to the closed-loop control. The paper presents the method for measuring rotor orientation based on machine vision. The pattern code generation, deriving method and pattern processing algorithm are introduced. With the model built in OpenGL, measurement errors of three degrees of freedom (DOF) are derived. Resolution and accuracy of the measurement method are analyzed. Considering the measurement of time delay, the effect on PD control system with simplified dynamical model of spherical motor is presented.