Research On Semi-active Suspension System Based On GSO-LQG Control Algorithm

As an important part of impacting vehicle riding comfort and operational stability,suspension is always a research focus in the automotive field,which semi-active suspension has got a extensive application because of its low energy consumption and convenient adjustment.How to improve the performance of semi-active suspension system has become an important subject in the field of modern automobile research.The study of improving the performance of the suspension system is generally considered from two perspectives:the first is to improve the suspension’s performance by changing the mechanical structure of the suspension;the other is to design a good control method for improving the robustness of the system,which can make the vehicle meet the requirements of comfort and security when driving on various kinds of road surfaces.Therefore,a new type of semi-active suspension structure is taken as the research object in this paper,the control performance of the suspension system is studied based on the GSO-LQG control algorithm.In addition,energy feedback system is considered as well.The main contents of this paper are summarized as follows:(1)A new type of damper with damping-adjustable and energy feedback function was proposed,and the three-dimensional modeling of the damper was modeled with the SolidWorks software.The mathematical model of the damper and the energy feedback model were established,and the feasibility of damping-adjustable and energy recovery was demonstrated theoretically.Which lays a solid foundation for the following simulation and performance evaluation of vehicle suspension.(2)The mathematical model of the pavement signal was established based on consideration of the pavement level and the speed of the vehicle.The simulation model of the suspension system was established according to the mechanical model and the state space expression,the energy feedback characteristics of the suspension were analyzed,and the LQG controller was designed.The advantage of LQG optimal control method was verified by comparison with PID control and fuzzy control process.(3)Improvement measures such as chaos initialization,variable step-size and crossover,mutation operation were put forward.The result shows that the modified GSO algorithm’s precision and optimization efficiency is improved,and it shows an obvious advantage especially in the multi-parameter optimization.(4)The full-vehicle suspension system simulation model was established based on the state space expression of the vehicle suspension.The GSO algorithm was introduced into the parameter tuning process for the LQG controller,and the GSO-LQG control algorithm was designed by the data exchanging between the GSO algorithm program and the simulation model.The simulation experiment was made,in which semi-active suspension controlled by GSO-LQG algorithm is compared with passive suspension and the semi-active suspension controlled by PSO-LQG algorithm.The result shows that GSO-LQG control algorithm improves the performance of the vehicle suspension system apparently.