Research On Modeling And Control Of Energy-regeneration Automotive Suspension System

Suspension system is the most important part in automotive system. With the development of the living standards, people's demands for the vehicle's handling stability and ride comfort is increasing. The traditional passive suspension can't meet this requirement, so that the researchers are attended to develop a new suspension system which could adjust damping force to the state of car. The active and semi-active suspension system can enhance vehicle's handling stability and ride comfort observably.To analyze the characteristic of the active and semi-active suspensions system, this thesis presents the energy-regeneration suspension system, which combines the active and semi-active function in one and has a great future. So the author has made an intensive study of the energy-regeneration suspension system.The main work and result of this thesis including the following aspects:1. The comparative analysis of vehicle suspension's modeling method has indicated that the Bond Graph is a better method to the modeling of multi-energy field system. The 2 degree-of-freedom and 7 degree-of-freedom Bond Graph model of the energy-regeneration suspension system were established, and the Bond Graph models were converted into Block Graph model and state equation respectively. Based on Matlab/Simulink the numerical simulations of suspension systems are implemented.2. Based on random phase theory the power spectrum density of road was converted into time-domain road roughness model. The simulation and analysis were done on the C grade road. The results indicate that the power spectrum density of road roughness obtained is the same as given.3. Based on linear quadratic optimal control method the simulation and analysis of 2 degree-of-freedom and 7 degree-of-freedom energy-regeneration suspension system were done. The results indicate that the linear quadratic optimal control method can reduce major indicators of the car observably, and prove that the linear quadratic optimal control is a better method to control the vehicle suspension system.4. The experiment of the energy-regeneration electric control suspension was done. The results indicate that the energy-regeneration suspension can reduce sprung mass acceleration and the deformations of suspension system obviously, and prove that the energy-regeneration suspension system can enhance vehicle's handling stability and ride comfort effectively.The research and achievements in this paper laid the groundwork for future research of the energy-regeneration suspension system.