Design Of Adaptive Headlamp Leveling System Based On S32K14x Series ARM Platform

As a very common walking tool,automobiles have entered thousands of households.With the increase of automobile sales in our country year by year,people put forward higher requirements for safety and comfort in the driving process.During night driving,the headlight is undoubtedly an important part that affects safety and comfort.Now the automotive industry has made considerable progress and development in electronics,network,machinery and information,which provide the technical basis for the development of adaptive headlight control system.The adaptive headlamp control system is an intelligent real-time light following system.By consulting the relevant research progress at home and abroad,this paper designs a headlamp leveling control system in which the optical axis of the low beam swings up and down in the vertical direction with the change of the vehicle’s pitch angle.The main contents of the study are as follows:First,the structure of the system is introduced,which is mainly composed of sensor,transmission path,main control unit and execution unit.The sensor is responsible for collecting all kinds of information about the car body,and the transmission path uses CAN bus and LIN bus for data transmission.The main control unit is mainly composed of the control chip S32K148 and its peripheral circuit,which is responsible for the operation of algorithms and programs,and the execution unit is used to execute the instructions issued by the main control unit.Then the algorithm is designed according to the actual needs.The parameters of the car body are defined,and then the dynamic illumination angle of the low beam is analyzed according to the mathematical formula when the car is stationary,leaning forward,leaning back,following the speed of the vehicle,uphill,downhill,etc.and introduce the mapping relationship between the position of the stepping motor and the illumination angle.Then the hardware circuit is designed according to the algorithm and function.The hardware circuit mainly consists of control chip S32K148,CAN transceiver module circuit,LIN transceiver module circuit,watchdog circuit,ADC module circuit and so on.The schematic diagram and PCB are drawn using Altium Designer 18 software,and the actual circuit board is finally made.At the software level,the S32 DS software of NXP company is used to map the pins of the main control chip S32K148,and C language is used for programming.The main programs are CAN communication program design,LIN communication program design,ADC collection function program design and watchdog function design.After the validation of hardware test and software program design,the designed system is tested in real vehicle.The system collects all kinds of body information of automobile in the state of uniform speed,acceleration and deceleration,and the data is transferred to the upper computer through CAN bus.Then,the dynamic illumination angle of the low beam is calculated by using the MATLAB software according to the algorithm.In the actual driving process,the frequent jitter of the motor will cause the driver visual fatigue,so the calculated dynamic illumination angle is smoothed and filtered.Using the filtered illumination angle,the target position of the dimming motor can be obtained by mapping the stepping motor position to the illumination angle.Through debugging and testing of the actual function,it is verified that the headlamp adaptive leveling system designed has good practicability,meets the requirements of the project,and achieves the expected adjustment effect.