| Automotive engine cooling system is the key factor of affecting engine efficiency and safety. This paper presents and designs a controller of automotive engine cooling system based on fuzzy control in order to improve the efficiency of the engine, extend engine life, save fuel, reduces pollution for the imperfect problem of the structure and control of the traditional automotive engine cooling system. The controller combinates intelligent control with microprocessor to control the engine cooling control system, so that it can gain the best temperature of cooling fluid under the complicated working conditions.Firstly, this paper introduces the composition and principle of the automotive engine cooling system and analyzes mathematical model. According to the practical application of the cooling system designs the engine cooling system including the overall structure of the controller. Secondly, the characteristics of engine cooling system are time-varying, uncertainty, hysteresis and non-linear. This paper develops fuzzy PID control strategy in detail which combinates intelligent control with conventional control, including: input and output variables of fuzzy, subordination function to determine, design of fuzzy rules and draw fuzzy control table. The hardware part uses AVR mega16 microcontroller as the core of microprocessor, and uses the SG3525 chip as the core of the drive unit. The software part is designed with C language for fuzzy PID algorithm, data acquisition, AD and DA procedures. As a result, the fuzzy PID controller can achieve real-time data acquisition, and can output corresponding control. Finally, the fuzzy PID controller is used multi-group experiments in a variety of changing conditions. After repeated experiments, the result shows that the system can run stable for a long time, achieve good control effect, meet the engineering requirements, and improve control accuracy in the larger range of the object properties change. |
PDF Full Text Request