| The illumination condition of the front light in the vehicle directly influences the possibility of the traffic accidents when it runs at night.So Advanced Front-lighting System is of great significance to improve driving safety by enhancing work performance of the front light.This thesis firstly analyses Advanced Front-lighting System in theory,builds a mathematical model of front light’s deflection angle based on dynamic model of two-degree freedom by analysing driver’s behavior of foresight,parking stadia,safe braking distance and so on.It gets the front light’s illumination curve of equilux using Lucidshape,carries a further on the defection start condition of the system and makes the defection start condition based 5lux illumination curve.And then it studies and analyses the control algorithm deeply and gets the new and improved Particle Swarm Optimization Algorithm with Operator crossover operation and mutation operation of Genetic Algorithm.It chooses parameters of PID control algorithm by using this algorithm,which makes a good control effect with relatively quick reaction speed and no phenomenon of over control.It builds the enforcement agency’s mathematical model of stepper motor,carries out a simulation analysis to and optimizes the improved method in the simulation platform of Matlab/Simulink which proves the rationality and superiority of the defection start condition and the control algorithm it studies intensively and improves the working performance of Adaptive Front-lighting System in the vehicle.Finally it builds the overall structural frame of the system according to design and functional requirements,designs scientific hardware circuit by module and draws the circuit diagram of the PCB board using Altium Designer.It selects MC9S08DZ60 from Freescale as the main control chip for the system and compiles programs in C language through Code Warrior,the specially appointed programming platform for this kind of singlechip.It designs the software for the system according to the control strategy made in this thesis and draws the overall control flowsheet with a design idea of modularization for the software of the system partly.Furthermore,it builds test bench to conduct a semi physical test which proves the practicability and the relatively high control accuracy of the system’s control method the thesis puts forward.Combining theoretical analysis method,simulation with the bench test,this thesis offers a practical control method to improve the working performance of Advanced Front-lighting System making great difference in improving the safety of driving at night.At the same time,it offers a new idea for the control method of Advanced Front-lighting System,facilitating the progress of the front light’s development to some extent. |
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