How to Ensure Optimum Night-Time Vision for Drivers with Adaptive Front Lighting (AFS)
Adaptive front lighting, or AFS, is a new smart automotive application gaining acceptance among car buyers, legislators and road-safety groups. By using stepper motors to adjust the headlamp position for pitch and also horizontally as the driver steers, AFS can ensure optimum night-time vision for drivers while also enhancing comfort and safety for other road users. Controlling headlamp movement in response to inputs from various sensors around the vehicle requires motor drivers that are not only fast and accurate but also reliable and fault tolerant. Adaptive stall detection is an important diagnostic function that cannot be supported by all stepper-motor driver ICs. A driver that is capable of sensing and communicating the motor back EMF to the host controller provides the information the software needs to prevent lost steps and maintain consistent control over the headlamp position.