The design on Adaptive Front Lighting System (AFS) based on brushless DC motor

Adaptive front lighting system(AFS) is most advanced vehicle lighting system, which can greatly reduce driverpsilas fatigue degree when driving on curve road at night, make driver clearly see actual road surface at turn around, make driver have abundant time to deal with emergency, and evidently promote safety at night. Most high class vehicles have been fixed AFS in Japan, meanwhile AFS will be used in China soon. At current, most AFS vehicles adopt stepper motor, whose merits are that motor price is cheap, control algorithm and controller hardware are very easy, control precision is high, whose maximal shortcomings are as stepper motor adopts open-loop control,loss steps often happens, which can affect control capability. In this article, based on brushless DC motor (BLDC) AFS controller system is designed: Simulink/Matlab model is setup, position sensor only adopts three hall elements,simulation results and experiment show that BLDC has more quick response speed than stepper motor. But to a small given reference steps, there exists small error.