Suspension System Design And Chassis Tuning Of Electric Vehicles

Electric vehicles are driven by electric motor using vehicle power supply. It has to be in accordance with traffic regulations and safety laws. The main advantage of electric vehicle is that it does not exhaust harmful gas which pollutes the air. Being the development direction of Chinese automobile industry, it means a lot to energy structure optimization and drive feeling improvement.The Suspension that connecting wheel and body is the vibration isolating unit composed of spring and damper. It mainly absorbs vibration transmitted from ground to vehicle body. The power train of electric vehicle is different from that of traditional vehicle. It requires that electric vehicle suspension development has to focus on vertical dynamics and anti-pitching performance. The suspension of Chinese developed electric vehicle falls behind suspension in developed countries in hard point optimization, structure design, chassis adjustment and components manufacturing. So there is great value of further researching suspension system and vehicle handling and ride performance adjustment.As a result, the vehicle suspension system design scheme is proposed using math calculation firstly. Then it is analyzed and optimized by simulation. Lastly the suspension which improves the vehicle performance is determined by chassis adjustment. Analyzing the experiment results can prove the designed suspension accords with design definition and provide foundation for production.(1) According to the parameters gained from benchmarking and project definition that the developed vehicle faces the taxi market,high demands are expected from customers for the ride and handling performance. The vehicle product definition requires high technical standard for the suspension system. Suspension style is to be designed reasonably. The performance parameters of key components such as stiffness of coil spring and suspension were designed. The suspension structure was designed according to hard points location and layout space.(2) The multi-body dynamics model of chassis system is built according to vehicle suspension hard points. The kinematic validation is performed for the suspension. The stiffness of coil spring, stabilizer bar, rubber bushing and damping coefficient of benchmark car is referenced. The model parameters are defined using design value and compared with theory results of design database. The suspension system is simulated and the precision is evaluated by experience. It is optimized by simulation and three sets of components are used for making prototype.(3) The subjective evaluation of vehicle road tests is performed firstly. The handling stability and ride performance is mainly focused on. The parameters of each set are analyzed and see if it meets the product definition. The key performance parameters which need optimized were assessed. The optimized scheme is selected for releasing parameters. The handling stability and ride performance is tested according to national standards. The technical parameters are determined if the test results meet the design targets.