Passenger Car Engine Cooling Fan For The Development Of Intelligent Control System

With the rapid development of our country economy, people living standard rise, the car is becoming more and more irreplaceable role, especially the development of bus provides great convenience for people’s travel. But traditional passenger car cooling system has many drawbacks, causing a lot of air pollution, which has affected people’s life. Therefore, the development of passenger cars in its cooling requirements at the same time meet the national discharge standards is a key way for the future development of passenger cars.At present, the domestic most of the bus company production of passenger cars equipped with cooling system by the water tank, water pump, radiator, and the cooling fan, etc. Traditional passenger car engine cooling system, although also can meet the needs of passenger car radiator, but its efficiency is low, the effect is not ideal, the speed of the fan and water pump of engine speed has a lot of dependencies, does not vary according to the working condition of the passenger car engine do corresponding adjustment, the engine at low speed high load work, insufficient cooling, low engine speed load work, excessive cooling. Therefore, in order to make the passenger car engine cooling system and the working condition of engine matching, need cooling fan and water pump and engine completely decoupled. This design adopts electronic fan instead of the original mechanical fan, the original traditional pump replaced into dynamic, in order to realize the automatic control system also need to the temperature sensor and single chip microcomputer.This topic research is the content of the passenger car engine intelligent cooling system, the working principle of the system is installed in the import and export pipe and cooling water tank installed in the cold of the trachea temperature sensor detection in and out of the radiator coolant temperature and engine inlet temperature, the temperature of the detected signal is converted into electrical signals into after PIC microcontroller. PIC MCU receives the temperature signal into electrical signal after the analysis and calculation, and output the corresponding PWM control signal according to the results of the calculation, the control signal after amplification circuit amplification respectively driven radiator fan, inter-cooled fan and water pump speed. Cooling fan cooling air will radiator and inter-cooled redundant quantity of heat to go around and pump speed will change different cooling fluid flow in the cooling line, cooling fluid flow changes will absorb the heat engine, to ensure the normal work of engine.The output of the control signal in the form of PWM pulse, due to the nature of PWM pulse, can realize the infinite variable speed pump motor and fan motor, which can make the water pump and fan according to the coolant temperature and inlet temperature of CVT. Then, can according to automatically adjust the working conditions of engine cooling fluid flow and cooling fan speed, ensure engine excess heat scattered into the air, and in a timely manner so as to make the engine work in the normal temperature range.In addition, in order to realize the reliability of the system control and comfort, the PID control method based on feedforward. Introduce the PID control based on feedforward can according to the change of working condition of engine cooling system for predicting the heat release, at the same time, according to the change of environmental temperature and speed regulating actuators, which can effectively solve the problem of hysteresis control cooling system.