Joshi, M., Singh, H., Kalia, S., Dalela, S. et al., "Differential Speed Based Bend Lighting in Adaptive Front lighting system," SAE Technical Paper 2009-28-0022, 2009, doi:10.4271/2009-28-0022.
Bend lighting is achieved in two ways: static bend lighting and dynamic bend lighting. In both these cases the turning angle of the vehicle is required. Mostly this angle is calculated from the steering angle or in some systems through GPS. The first method has many drawbacks like it is dependent on the type of steering (mechanical, hydraulic or electrical) so it can not be a universal system. In the other method GPS based bend lighting is a very expensive solution and also GPS cannot be accessed from everywhere at all instances.In this publication the difference in speed of front wheels of a vehicle while turning is used. By using the speed of the front two wheels the actual turning angle of the vehicle can be calculated.This method is better suitable as it is not dependent on the type of steering: mechanical, electrical, hydraulic or even a joystick. It also is independent of the ratios between the steering wheel, steering shaft and the attached gear.This system can also be clubbed with the speed based beam adaptation for AFS and ABS (Automatic Braking System) hence increasing the efficiency and decreasing the overall cost of the vehicle.