Safe adaptive front-light microcontroller with symmetric angle compensator for abnormal steering-swivel angle protection

AFLS (Adaptive front lighting System) is one of additional hardware-software systems, which is being applied to improve safety in driving automotive at night. Because automotive ECU(Electronic Control Unit) hardware is under severe environmental noise, safe embedded system in controlling headlamp has to be tightly designed by considering safety requirement in terms of hardware-dependent software. In this paper, we propose an adaptive headlight controller with newly-designed symmetric angle sensor compensator and its algorithmic software, which is integrated with ECU-based adaptive front light system. The proposed AFLS controller with the protection software effectively detects abnormal situation and restore safe status of controlling the light-angle in AFLS operations by comparing result in symmetric angle sensor. The controlled angle value is traced into internal memory in runtime and will be continuously compared with the pre-defined lookup table (LUT) with symmetric angle value, which is used in normal operation. The watch-dog concept, which is based on using angle sensor and control-value tracer, enables quick response to restore safe light-controlling state by performing the backup sequence in emergency situation.