Design Of Intelligent HID Automotive Front-Lighting System

Automotive lamps'low beam as a traditional road driving lighting, it could work only in one mode which is exactly an immovable light shape, low illumination and short life cycle. But the actual road surrounding and driving condition are extremely complex, for example road corners, devious roads, the difference highness of roads. That's why the topic, traffic-safety became a big problem. With the auto electronic technology developing, the requirements from people of driving in the night are raising up. So, at the beginning of the century, the High-Intensity-Discharge (HID) lamp with the Adaptive, Frontlighting System (AFS) became the most of famous car makers'investigation favor which can match the requirements much better.This article introduced AFS lamp the beginning, developing and application status, then I analyzed the constitution, function and system work theory. After the developments of HID driving and AFS control were introduced in detail, the system was designed based on the DSP technology. The parts of DSP controller, HID driver circuit and AFS motors coltrollers are including in the system. In the section about hardware, there are CAN bus controller, Flyback DC/DC converter, HID lamp start up, DC/AC full bridge inverter, lamp voltage and current sampling, load and steering wheel angle sensor module, step motors driver module. In the section about software, there is a whole system flow chart including basic program, application program, and arithmetic program, all above realized a complete system. From the system test result, we got the conclusion that this system can realize not only the HID driving but also AFS control function. All of these make sure to provide drivers the best lighting in many kinds of conditions. The result of the test also shows us the feasibility and correctness of the design. The whole system can reach the requirements of ECE R48 for lighting.At the end of the paper, summarize for the design. There are some functions will be improved, I think they could be the ideas for improving the system in the future.