Simulation Research Of Roll Control System Of Tractor Semi-trailer Study

With the rapid development of the economy, the transportation makes a remarkable progress at the same time. High speed, high efficiency and heavy-type are the direction of the transportation. With adjust of the policy, tractor semi-trailer is becoming the trend of development. This is because tractor semi-trailer can do some special work, such as"section transportation"and"trailer transportation"and so on.The center of the heavy-type vehicle is high and the track width is narrow, then it is easy to happen roll accident. Thus, safe,stability and maneuverability is becoming important research project. In order to improve the roll stability of the tractor semi-trailer, doing some theoretic research of the active roll control system in the paper, the anti-roll bar can actively control of the vehicle.In chapter one, the development status of the heavy duty and the anti-roll technique of tractor semi-trailer at home and abroad are introduced, and raising up the research problem. The research object is tractor semi-trailer, making some modification of the previous vehicle model and using LQR method to actively control the vehicle.In chapter two, some theoretic knowledge used in chapter three and four are introduced, including the auto-control system and optimal control theory. This makes for the research work of the paper. In chapter three, the 8 degree vehicle invariable speed model is established. In order to simulate the invariable speed driving condition, analyzing the load transfer condition and the active roll moment of the tractor semi-trailer. Thus, it can design the active roll control system much better.In chapter four, the LQR method is introduced, the Linear Quadratic Optimization is to optimize system performance and control target. There is interrupt (steering input) in the system, using the filter to deal with the interrupt, and designing the full-state feedback controller to optimize the system.In this paper, using MATLAB/SIMULINK to simulate several elements, such as the lateral road transfer,suspension roll angle, lateral acceleration and active roll control moment and so on. It found that, the roll stability advances 39% if the tractor semi-trailer with active control system.Active roll control system roll the vehicle body into corners while turning, which can improve roll over threshold, implying improvement of the roll stability effectively. It does preliminary simulation analysis, establish sure foundation on active roll control system further to research and develop.