Hall-Sensor-Based Magnetic Force Modeling and Inverse Modeling for Hexapole Electromagnetic Actuation

This article presents the Hall-sensor-based magnetic force modeling and inverse modeling for the hexapole electromagnetic actuation. Whereas mathematical models are derived for a specific hexapole electromagnetic actuating system, the results can be applied to other multipole electromagnetic actuators. Previously reported current-based force modeling and inverse modeling are subject to the combined hysteresis effect of multiple electromagnetic poles, resulting in significant error when being applied to produce magnetic force. To solve the challenge via direct measurement, Hall effect sensors are integrated into the hexapole system to measure the magnetic flux associated with individual magnetic poles. A Hall-sensor-based magnetic force model is then derived analytically, and the force gain and the associated voltage-flux gain matrix are determined via experimental calibration. The improved accuracy in force modeling is experimentally validated. Inverse modeling is then derived to render force production and to enable active control using the hexapole actuating system.