The Design Of Automobile Air-Conditioner Control System Based On AVR Chip-Microprocessor

With the upturn of the people’s living standard and the development of automobile industry, automobile air-conditioner as an important part to improve the ride comfort of the vehicle, it is more and more valued by the manufacturer and the customer. Automobile air conditioner system can automatically adjust the vehicle air temperature, humidity, cleanliness, wind speed, etc., so that can make a certain vehicle speed and direction of air flow, the crew can feel a good climate.In a variety of outside weather conditions, the ride comfort of vehicle can be improved and the staff can be in a comfortable environment.Due to non-linearity and large disturbance of automobile air-conditioner system, it is dificult to build exactitude mathematics model and get satisfied purpose by traditional control mode. This paper uses the logic fuzzy control theory to research on intelligent control to the indoor temperature regulating system of the automobile air-conditioner. According to decomposition principle of the fuzzy conrtol rule base, This article divides the entire controller into two inputs and single output system.First of all, we take the temperature difference (hypothesis temperature and vehicle indoor temperature) and change rate of the difference as input parameters, and carried on fuzzy processing and quantization to input parameters. Then we establish fuzzy membership grade of the inputs according to fuzzy membership functions. Second, we establish fuzzy control rules and fuzzy outputs according to practical experience. Finally, we translate fuzzy outputs to precise output value according to output fuzzy membership functions, then we can control wind speed of air-blower and the open degree of blending damper.We use fuzzy control tool box in Matlab/Simulink module to design the fuzzy controller. We use AVR chip microprocessor to design hardware circuit and main program and each subprogram of software system.