Research On Adaptive Fuzzy PID Control Of Electromagnetic Hybrid Active Suspension

During the driving process of the vehicle,the amplitude and frequency of the road excitation fluctuate greatly.The traditional passive suspension damping and spring stiffness are constant,and the damping force cannot be actively adjusted according to the road surface level to ensure the good comfort of the occupants.In order to improve the dynamic performance of vehicle suspension on different grades of road surface and reduce energy consumption,this paper is funded by the National Natural Science Foundation of China(51775426)to design an adaptive fuzzy PID control strategy for electromagnetic hybrid active suspension based on road grade information.Suspension adaptive control of road conditions and recovers part of the vibration energy.On the basis of analyzing the structure and working principle of the electromagnetic hybrid active suspension system,ignoring the coupling effect of the front and rear wheels,and only considering the vibration response of the single-wheel suspension system,the dynamic model of the two-degree-of-freedom electromagnetic hybrid active suspension,the linear motor model and the Mathematical model of solenoid valve shock absorber;using the beetle algorithm(BAS)to optimize the initial weight threshold of the BP neural network,training the BAS-BP neural network according to the random road model,road grade classification and suspension dynamic response data,and establishing the BAS-BP Pavement grade recognition algorithm:On the basis of road grade recognition,the control objectives are determined according to the different road grades,the controller parameters are designed to adjust the objective function,the sprung mass acceleration difference and its change rate are used as the input of the fuzzy PID controller,and the main Dynamic feedback,establish variable universe fuzzy controller and parameter adjustment fuzzy controller to jointly adjust fuzzy PID parameters,so that the suspension system can improve the control accuracy without changing the basic universe of input and output.Under the mixed road level input,simulation analysis The control effect of the adaptive fuzzy PID control strategy in the time domain and frequency domain response;design the active suspension energy feeding circuit,analyze the working principle of each mode of the circuit,determine the parameters of each component of the circuit,and use the nonlinear double closed-loop control strategy to control the circuit.The duty cycle of the power switch tube is adjusted,the circuit model is built and the simulation analysis is carried out;the physical prototype of the electromagnetic hybrid active suspension is trial-produced,the hydraulic vibration table is used to simulate the random road grade input,and the electromagnetic hybrid active suspension adaptive is carried out in combination with the hardware-in-the-loop simulation system The control strategy is tested to verify the effectiveness of the adaptive fuzzy PID control strategy.The simulation results show that:under the time domain response,compared with the fuzzy PID control,the RMS value of the suspension adaptive fuzzy control is reduced by 13.28%and 13.84%respectively in the A and B grades of road sprung mass acceleration,and in the B,C and D grades.The root mean square value of road tire dynamic load is reduced by 9.09%,16.07%and 15.54%respectively;the dynamic deflection of suspension is reduced by 21.96%compared with passive suspension,which better prevents the possibility of hard impact with the limit point of suspension travel;and A vibration energy recovery of 42.8W is achieved.In the frequency domain response,compared with the fuzzy PID control,the suspension adaptive fuzzy control reduces the peak value of sprung mass acceleration by 18.6%and 12.47%on the A and B grades,respectively,and the tire dynamic load peaks on the B,C,and D grades respectively.The reductions are 15.49%,16.81%,and 12.43%,and the peak suspension dynamic deflection on the D-level road surface is reduced by 17.05%.The test results show that the relative errors of the root mean square value of the sprung mass acceleration in the test and simulation time domain are 3.73%,7.64%,13.55%,and 15.19%,respectively,under the road grades A,B,C,and D,and the relative errors of both are equal.Within a reasonable range,the effectiveness of the adaptive fuzzy PID control of the electromagnetic hybrid active suspension is verified.