| With the rapid development of automobile industry and automobile speed increase,people put forward higher requirements for the comfort and safety of vehicle,and the vehicle suspension affects the ride comfort,handling stability and ride comfort.In automobile suspension,the general elastic element has the function of absorbing and storing energy,in addition,it must bear the weight and load of the car body.So in general semi-active suspension is not concerned about the stiffness of suspension.According to the control strategy of semi-active suspension system,this paper uses the method of theoretical analysis and model simulation:The main research contents and results are as follows:1.discusses the background and significance of the topic.This paper introduces the structure,classification,function and application of the control algorithm.Describes the changes and development of active suspension as well as the domestic and foreign latest research results,the semi-active suspension control as an example to illustrate the analysis of Co-simulation of ADAMS and MATLAB has important significance for the analysis and design of control strategy of active suspension;2.through the performance evaluation index of suspension as an example,the influence of suspension system on vehicle ride comfort and handling stability is discussed in detail.Based on the random road surface as the input signal,the input model of road surface spectrum is established,and the concept of power spectral density and road surface roughness is described.Based on the model of passive suspension,the vehicle body acceleration,suspension travel and tire dynamic displacement are simulated and analyzed.3.for single wheel,half car active suspension and passive suspension,ADAMS/View software is used to model the system,and the communication between ADAMS software and MATLAB software is established by using ADAMS/Controls module;4.on the basis of the linear quadratic form,the control strategy of semi-active suspension for vehicle ride comfort is studied.On the basis of this,the multi-objective optimization and innovation of LQR control weight coefficient is improved by.The LQR control and the theory of multi-objective optimization combination,get active suspension linear two type active suspension controller,the control effect is better,the performance index of LQR controller design is set for integral and weighted square suspension travel and tire dynamic load and vertical acceleration value.Compared with the single objective optimization problem,the outstanding feature of the multi-objective optimization problem is to optimize each target to achieve the optimal value at the same time.However,due to the conflict between the various objectives of multi-objective optimization problems,in order to meet one of the objectives of the best,while other objectives are often affected by it and become very poor.Therefore,the multi-objective optimization theory has a natural advantage in dealing with these problems.5.using ADAMS software to establish the active suspension and passive suspension mechanical model into MATLAB software,establish the simulation model according to the three different control strategies,will import the ADAMS file as a subsystem module,Co-simulation on the suspension system,the simulation results are analyzed,the results show that the LQR control and its weight coefficient is correct and the algorithm's validity. |
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