Study On Handling Stability Of Caravan

Caravan is a type of trailer vehicles, which is quite popular in European and American countries. The handling stability of this type of vehicle, which is the focus of researches in this field, determines the safety performances of the trailer vehicle.In order to research the handling stability of caravans, in this dissertation, Differential Equations for rigid objects were firstly created according to principles of Rigid Body Dynamics, and the equations can be solved by using programs edited by MATLAB software, so that Dynamic model of Caravan is developed, and the simulation model was developed with MATLAB/SIMULINK according to the dynamic model. Rationality and correctness of the simulation model is proved by the results of simulation and experiment. This work offered a platform for researching match and joint between tractor and trailer.Root-locus method is used to research into the influence of application of caravan and structure parameters on the handling stability of the caravan, providing a theoretical basis for the match and joint between the tractor and the trailer. The research further deploys the root-locus method by organically combining the stability factor with the root-locus method in automatic control engineering, making it easy to analyze the stability and dynamic performance. The developed root-locus method contributes to both direct judgment of the advantages and disadvantages of vehicle handling stability and analysis on the influence of main factors of handling stability, providing a new path for probing into vehicle handling stability.High-speed shimmy is a major hidden danger for accidents of combination vehicle. By using deflation method approach, in which high-order system of caravan is deflated to second-order system, it is deduced that the speed is inversely proportional to system damping. The dissertation reveals the causes for high-speed shimmy of caravan, and researches into the impact of structural parameters on system damping ratio.Driving stability control is an effective way of improving vehicle handling stability. Simulation control is performed on the caravan by using the variable structure control method, and tests are conducted on high-speed shimmy of caravan by using LabVIEW virtual control technology. Test results show that the controlling strategy is effective.