Research And Simulation Of Active Air Suspension Based On Fuzzy PID Control

The transportation of commercial bus is an important part of passenger transport,which plays an important role in people's travel.As the promotion of the popularity of the automobile and the improvement of the technical level of the vehicle,the walkers have higher requirements of riding comfortable.And the performance of the suspension directly affect the operation of the vehicle stability and riding comfortable.Long-distance commercial bus are usually equipped with passive air suspension system,which is characterized by relatively fixed suspension parameters(stiffness and damping).Only part of the road conditions are the basic of designing usually.When changing the operating conditions,the vibration of the filter and the buffer of impact is weakened.The active suspension can be based on changes in the driving environment,of which adjust the suspension parameters to enhance the shock absorption effect.Taking into account the differences in vehicle parameters and properties,the active air suspension currently is equipped in car for controlling directive of airbags does not necessarily apply to commercial bus in terms of safety.In this thesis,a parallel active air suspension with cylinder as actuator is selected as the research object.High security redundancy is characteristics of the air suspension,no need to make a big change to the system structure;And the two-degree-of-freedom 1/4car suspension of commercial bus which is numbered a certain type of 6900 bus as the object of research.By researching the passive suspension,active air suspension dynamic model respectively,based on the filtered white noise and input the road parameters as vibration input model.Select fuzzy PID strategy as a controller to design fuzzy control rules in Matlab/Simulink operating environment,PID controller,and attached to a passive suspension,active air suspension simulation model.Output the simulation curve of the three parameters evaluating the performance of the suspension:vehicle body vertical acceleration root mean square value which is called as BA,;suspension movement stroke which is called as SWS;tire movement displacement which is called as DTD.Through the analysis and comparison of the evaluation parameters of the improvement.It shows that parallel controller with fuzzy PID control active air suspension not only guarantees the safety redundancy,but also improves the performance index compared with the passive air suspension.