Analysis and Improvement of Ill-conditioned Problem in Typical Impact ModelsZHANG Jian1,3,ZHANG Xin2,LI Jiang3(1.School of Traffic and Construction Engineering,Beihua University,Jilin 132013,China;2.School of Traffic and Transportaption,Beijing Jiaotong University,Beijing 100044,China;3.School of Transportation,Jilin University,Changchun 130025,China)In order to solve the ill-conditioned problem in vehicle accidental typical collision impact models,a improvement method was established on the basis of the Linear Zone and the Interior Product Zone theory.The ill-conditioned problem nature was analyzed by this method,which showed that the ill-conditioned problem was caused by the serious linear interrelation between some equations in the models.The authors of this paper eliminated the linear interrelation by the equality shift,then solved thorough the ill-conditioned problem by constituting the model anew.The calculation results of an application show that the reconstructed models accuracy overtakes obviously the models by reducing the calculation result error large,it will give a new method for solving the model ill-conditioned problem.vehicle impact accidental models;ill-conditioned problem;reconstructed models