Research On Electromagnetic Actuator For Vehicle Active Suspension

The vehicle suspension system is one of the important components in the vehicle chassis assembly.Improving the performance evaluation index of the vehicle suspension system plays an important role in improving the overall stability and smoothness of the vehicle.The passive suspension system of the vehicle is not ideal because it is difficult to meet both the requirements of stability and smoothness.For the semi-active suspension,because there is no inputing force of the active control,it is not as active suspension as the steering stability and the smoothness.For the research of vehicle active suspension system,research based on control strategy has been fruitful,but for the important component actuators in the active suspension system,its research is still lacking.Therefore,this thesis mainly studies the important system of electromagnetic actuators for active suspension.Based on the overall summary and analysis of the current research results of domestic and foreign research,this paper develops based on the important basic theory of Faraday's electromagnetic induction law.An electromagnetic actuator that can be used with active suspensions to discuss some of the influencing factors of the electromagnetic force of the actuator.In addition,based on electromagnetic actuator simulation and experimental data,a more in-depth and comprehensive research work was carried out for the vehicle quarter suspension system.The main research contents and results of this paper are as follows:(1)A reasonable linear electromagnetic actuator was developed,and the permanent magnet pole number,primary size,secondary size and slot parameters were calculated in detail,and the appropriate permanent magnet magnetization mode,electromagnetic load and winding form were selected.Finally,an 8-slot 10-pole actuator was obtained.The finite element model of the electromagnetic actuator was established by Maxwell software,and the electromagnetic field finite element simulation was carried out to obtain the magnetic field distribution of the electromagnetic actuator.Based on this,the parameters such as the input voltage and running speed of the actuator were discussed.The influence of the input excitation on the response characteristics of the actuator is analyzed.It is found that the electromagnetic thrust of the actuator is inversely proportional to its synchronous speed,that is,the electromagnetic thrust will decrease with the increase of the synchronous speed.(2)The physical model and dynamic model of the electromagnetic actuator and the quarter vehicle suspension system were established.Based on this,the simulation model construction and simulation analysis were carried out by Matlab/simulink software,and then fuzzy-PID control algorithm and the optimal control algorithm respectively control the electromagnetic actuator and the two degree of freedom suspension system,and simulate and compare the control effects.After the simulation,the following results are obtained: for the actuator,the fuzzy-PID control algorithm can make the thrust and speed tend to be stable in a very short time,and the overshoot of the system is also small.For a quarter vehicle For the suspension system,the active suspension with optimal control strategy has lower performances of sprung mass acceleration,suspension dynamic displacement and tire dynamic displacement compared with the traditional passive suspension.thus it can improve the ride comfort of the vehicle and vehicle ride comfort.(3)According to the designed structure and parameters,the prototype of the electromagnetic actuator was prototyped,and the experimental device was equipped with the voltage regulator to carry out the experimental research on the electromagnetic thrust of the electromagnetic actuator.The experimental results are the same as the simulation results.It will increase as the input voltage increases,but at the same time the synchronization speed will decrease.Finally,a test bench for a quarter of the vehicle suspension was built and a prototype of an electromagnetic actuator was applied to it.