Research And Implementation Of Adaptive Control System For Automobile LED Headlamp

With the level of consumption improving,the car parc has been increasing year by year,and people pay more attention to automobile safety and environmental protection.In order to reduce the incidence of traffic accidents at night,the technicians have been making continuous improvement on the automobile headlamp.The domestic theoretical research is mainly focused on improving the bend lighting,and the research on full-function adaptive headlamp system is relatively less.At present,although halogen lamp and high intensity discharge lamp occupy a large share in the automobile headlamp market,their luminance efficiency and service life are not as good as Light Emitting Diode(LED)headlamp.Therefore,the research on the adaptive control system for automobile LED headlamp was carried out in this paper,the calculation models of the adaptive adjustment angle in horizontal and vertical dimensions and the calculation model of the far and low beam mode were established for the LED headlamp,the hardware development and the control strategy design of the system were completed,and based on the Mondeo LED headlamps,the test environment was built to realize functions' verification and parameters' measurement of the system,so as to the automobile headlamp,it provides a solution with less manual operation,low adjustment error and excellent performance.The main contents in this paper were as follows:(1)The control principle of the adaptive control system for LED headlamp was analyzed,and around the project requirements,the design schemes of hardware and software in the system were proposed.(2)After the analysis of the relationship between the parameters such as ambient light intensity,vehicle speed,steering wheel rotation angle,attitude angle of car body,etc.and the horizontal adjustment angle,the vertical adjustment angle as well as the far and low beam mode of LED headlamp,the calculation models of the adaptive adjustment angle in the horizontal direction,the adaptive adjustment angle in the vertical direction as well as the far and low beam mode were established successively.(3)The hardware development of the Electronic Control Unit(ECU)for LED headlamp was realized.The ECU used the automotive-grade chip MC9S12P128 as the main control core,and integrated the LED headlamp driver module,the horizontal motor driver module,the vertical motor driver module,the six-axis sensor module and the power module.(4)The system software design was divided into two layers: the bottom layer was the driver layer,and the top layer was the application layer.The driver layer design was to write ECU driver.The application layer design was to make the system control strategy,and realize the software development including the adaptive switching of high beam and low beam,the headlamp's adaptive adjustment in the horizontal direction,and the headlamp's adaptive adjustment in the vertical direction.(5)By building the system's test environment,the system's functional test was carried out.The test results indicated that the adaptive switching function of high beam and low beam,the headlamp's adaptive adjustment function in the horizontal direction,and the headlamp's adaptive adjustment function in the vertical direction could work on the adaptive control system for automotive LED headlamp researched in this paper,the horizontal adjustment ranges of left headlamp and right headlamp were-15° ? 8° and-8° ? 15° respectively,the adjustment error was within 0.5°,and the vertical adjustment range of the headlight was ±2.5°,the adjustment error was within 0.15°,the design requirements were met.