| The intelligent start system is a safe access and start technology based on base station and key.It enables users to unlock the door,open the trunk,start the vehicle and adjust seat without touching the key.Users can kick down the car to open the trunk while their hands holding something.The vehicle can automatically adjust the seat position when one of the couple carries different key into the vehicle.In the winter,users can warm the car at home before they launch it through the phone APP.It is convenient to operate and the design reflects the sense of science and technology while providing good support for the development of future intelligent vehicles.The intelligent start system development phase is now into the third generation.The first generation of smart start system using RFID(radio frequency identification)technology solutions,which requires users to insert key in fixed card slot to start vehicle.The second generation of intelligent start system adopts two-way communication solution.Keys must be carried in the body to start vehicle,and can’t control the vehicle over a long distance.The intelligent start system has entered the third generation development stage.The degree of intelligence is further improved.First of all,users can unlock vehicle,close window,start vehicle through their mobile phone.Also,users can monitor vehicle information on the mobile phone,such as whether the tire pressure is normal,whether the door lock is closed,etc.Furthermore,based on the accurate positioning of the key,the intelligent welcome function is realized,and the response speed and stability of the system are further improved.This paper conducts research and technical analysis on the third generation intelligent start system,develops an intelligent start system based on MATLAB,which realizes all the functions of the current mainstream thirdgeneration intelligent start system,Including keyless entry and start,remote control,intelligent welcome function.And compared with the current mainstream intelligent start system on the market,the system has improved in three aspects.In terms of the development process,In order to solve the problems of code quality is not high,poor readability,not easy to maintain,low test efficiency we encountered during the development process based on C language,we introducing embedded development process based MATLAB,the embedded platform is NXP MPC5604 B.Embedded development based on MATLAB has three advantages.First,MATLAB development method is graphical.The design and development of logic functions is achieved by modeling in SIMULINK,don’t need read and write text code,make the software easier to maintain.Second,Simulate testing and code generation with one-click operation by writing scripts,greatly improve code quality and test efficiency.Third,since the model does not depend on the hardware platform,it is only related to the logic function,so the portability is good.In the case of hardware platform changes,only the underlying driver needs to be changed.In the development process,whether the functional performance of the model,C code and hardware is the place that needs to focus on.This paper evaluates whether the model is developed correctly through MIL(model in the loop),evaluates whether the C code generated by the model is consistent with the original model through SIL(software in the loop),and evaluates whether the hardware burned into the code is consistent with the original model through HIL(hardware in the loop)and bench test.Through these tests,it is guaranteed that the final product function will meet the requirements as long as the model is designed correctly.In terms of radio frequency communication,this system introduces a frequency hopping design to solve the problem that the same frequency signal easily interferes with each other,resulting in low system stability.In the process of authentication,switch different communication frequencies to improve the anti-interference ability of the system and further optimize the communication protocol to improve the response speed of the system.This system integrates two remote control schemes,which are mutually redundant and improve the stability of the system while realizing different application scenarios.One is to combine T-Box(remote information processor)with second generation mobile communication data transmission technology to realize long-distance wireless communication with service background/mobile APP,and then exchange information with the system through CAN bus to complete far Distance vehicle control,The other is to combine BTM(Bluetooth controller)with Bluetooth wireless data exchange technology to realize close-range wireless communication with mobile APP,and then exchange information with the system through LIN bus to complete close-range vehicle control.The intelligent start system proposed in this paper was officially massproduced in April this year.The vehicle test shows that the product has excellent performance,fast response speed and high stability.At present,the system has been successfully applied to the Hongqi H5 of China First Automobile Group Co.,Ltd.,and the market has responded well.It is expected that the system will be applied in well-known domestic automakers such as Geely and Great Wall in the future. |
