| With the progress of technology and the improvement of people’s living standards,people have put forward higher requirements for the comfort of car rides,and the excellent interior air conditioning control system is a key factor in creating this comfortable driving experience.However,due to the complexity of the driving conditions of the car and the ambiguity of the human body,it is difficult for workers to establish a completely satisfactory mathematical model for the automotive air conditioning system.The intelligent control algorithm based on fuzzy control has been more and more attention.In this paper,the research object of automotive air conditioning system is the combination of heating and cooling.Firstly,the steady-state calculation method is used to calculate the thermal load of the whole vehicle,and the corresponding thermal load model is built on the Matlab/Simulink software platform according to the calculation formula of each heat load,and combined into a cabin temperature simulation module.Secondly,the four components of the air conditioning system have been selected and matched.The reasonable matching of the basic components of the air conditioning system is of great significance for improving the overall performance of the air conditioner.Next,the basic principle of the fuzzy controller is introduced.Combined with the need of this paper,the fuzzy controller of the three controlled mechanisms of the air blower,the mixing damper and the compressor has been designed,the input of the three fuzzy control modules are the temperature error and the temperature error change rate,and the output is the fan speed,the mixed damper opening and the compressor switch opening and closing.The above-mentioned cabin temperature simulation module,three control modules,and hourly temperature modules are integrated into the simulation model of the entire air conditioning system,and the fuzzy control algorithm is simulated to verify the accuracy of the fuzzy control algorithm.It can be seen from the simulation results that the fuzzy controller designed in this paper can quickly reach the set temperature of 25℃ from 40℃,and only a small range of deviation after the temperature is stable.As far as the driving conditions of the automobile in summer are concerned,the temperature after the smoothness has a deviation of about 0.2℃,which basically satisfies the requirements.Finally,in view of the possible shortcomings of the conventional fuzzycontroller,combined with the advantages of the PID controller,the fuzzy adaptive PID controller is applied to the automotive air conditioner.Unlike the fuzzy controller,the output of the fuzzy adaptive PID controller is for the variation of the three parameters of PID.The simulation results show that the improved controller can accurately control the temperature inside the car,meet the requirements of fast cooling,and has smaller steady-state error,which has better control effect than the fuzzy controller. |
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