Optimal Design Of Pure Electric Bus Front Suspention And Performance Analysis Of The Vehicle

With China’s growing energy shortage and environmental pollution problems, new energy vehicles gradually became a research focus of today’s automobile industry. At present, new energy vehicles include:pure electric vehicles, hybrid electric vehicle and fuel cell vehicles, pure electric vehicles as a new energy automobile technology is relatively mature, is an ideal point to relieve the strain on resources and solve of automobile exhaust pollution.However, the pure electric automobile chassis suspension system design, usually based on the traditional structure of automobile chassis, but as a result of motor instead of engine, battery box instead of fuel tank, and generally do not need variable speed device, the vehicle chassis quality distribution and shape structure significant differences compared with conventional cars, direct application, easily lead to weak front suspension stiffness, tire wear too fast and so on, which affect the operation stability, vehicle safety and ride comfort.In this paper, in the light of the main problems of pure electric bus front suspension exist, the optimal design method, in the traditional chassis suspension on the basis of the structure, the rational allocation of suspension stiffness, improve the tire wear, which improve the comprehensive performance of the vehicle.First of all, through the actual measure chassis, establish the virtual prototype model of the double wishbone independent suspension, and then optimizing the structure of torsion bar size to improve the stiffness of the double wishbone front suspension, the suspension of the overall design requirements. On the basis of this, the paper puts forward a kind of innovative design of the double wishbone suspension, broaden the suspension stiffness change space, and optimizes the suspension stiffness on this based.Secondly, in view of the double wishbone independent front suspension tire wear serious problem, the analysis of the sensitivity of various parameters on tire wear, selected comprehensive sensitivity parameters as design variables of optimization, and the suspension of the wheel camber Angle, toe Angle and wheel sideslip quantity as the main performance parameters. Using radial basis function(RBF) to construct the response surface approximation model, through the problem of multi-objective genetic algorithm for optimization, reducing tire wear effect.Finally, the optimization and the improved three double wishbone front suspension respectively carry on the same pure electric bus chassis model, build the virtual prototype model of pure electric vehicle of chassis, respectively according to national standard "test method for vehicle handling stability" requirements, on the national standard of steady turning experiment and steering portability. Carrying a optimization, the experiment results show that the improved double wishbone independent front suspension of the virtual prototype chassis, has the very good performance of steering portability, and on the vehicle steady turning performance is improved by about 12%. So that optimal design method proposed in this paper, which can effectively improve the pure electric vehicle chassis design, provide reference for pure electric vehicle development.