The Analysis And Multi-objective Optimization Of Vehicle Handling Stability

Vehicle handling stability refers to the ability which car can run stably under the driver’s operation; it not only affects the ease of manipulation of a car, but also determines the safety of a speeding car. The optimization problem of vehicle handling stability is a typical large-scale and multi-objective problem, it relates to the complex analysis process and many optimization indicators, so using conventional optimization methods can hardly obtain satisfactory results. In order to solve this problem, this paper intends to use self optimization algorithm and through ADAMS/Car, Matlab and Isight to do the design of vehicle handling stability.Firstly, a vehicle model is established and some vehicle handling stability simulations are designed in ADAMS/Car. The overall scoring functions about these simulations are selected as the objective functions. Then a Matlab script file is written for calculating the values of the objective functions automatically. In order to ensure vehicle ride comfort performance while optimizing vehicle handling stability, a ride comfort performance test is designed in ADAMS/Car and its evaluation function is selected as one of the optimization constrained functions. ADAMS/Car and Matlab are integrated into Isight by writing relevant documents and a sensitivity analysis of hard-points position parameters is conducted in Isight’s DOE module so design variables can be selected rationally, the parameters which have greater impact on the objective functions are selected as the design variables according to the result. Besides, the simulation of this paper is very complex, in order to improve the computational efficiency; an approximate model about ADAMS/Car’s simulation process is established based on the data obtained in the DOE process.MOGA is often used to deal with multi-objective optimization problem; however, the traditional multi-objective genetic algorithm always has some problems. In order to optimize the vehicle handling stability better, an improved multi-objective genetic algorithm is written based on the fixed point theory, and it is added into the Isight’s optimization algorithm library through Isight’s professional secondary development module SDK.Finally, an optimization design platform about vehicle handling stability is set up in the Isight based on the above works, its automatic calculation software is Matlab; model is the established approximate model; optimization algorithm is the improved multi-objective genetic algorithm. By comparing the before and after optimization values of all objective functions, the effectiveness of the optimization is verified.