Analysis And Optimization Of Kinematics Characteristics For Double Wishbone Suspension Of Motorized-driven Electric Vehicle

In recent years,electric and hybrid electric vehicles have got extensive development because of energy sources,environment and national policy guidance.Because of the breakthrough in technology and the innovation in driving type the technology of motorized-wheel-drive is regarded as the disruptive technology of new energy vehicles.However when existing vehicle platform is converted into the vehicle with motorized-wheel-drive,it will result in the physical interference among different systems.The unspring mass of vehicles will increase a lot because of the using of in-wheel motor,and this will directly influence the vertical dynamic performance.To solve these problems,the suspension system of the vehicle with motorized-wheel-drive for the selected in-wheel motor type is redesigned and recounted.However,the using of in-wheel motor will lead to the change of suspension structure,which will change various performance of vehicle including handling stability.So the author optimized the suspension to solve the problem of the change in handling stability.The inner rotor motor was selected to be the drive motor after comparing to outer rotor motor.The double wishbone suspension was selected after comparing the performance of multi-link suspension,double wishbone suspension and macpherson suspension.First the structure type of double wishbone suspension was selected,and then the damping element was redesigned and recounted.The guide mechanism in horizontal plane,longitudinal plane and vertical plane is redesigned and recounted.The model of suspension system with the calculated value was built in ADAMS CAR.The parallel wheel travel simulation experiment was done with this model.The kinematic character of prototype vehicle and target vehicle were compared and analyzed.Then the sensitivity analysis of suspension system was carried out in ADAMS Insight to find out the most sensitive location of hard point.According to the result of sensitivity analysis,the author proposed to divide the optimization procedure into two steps.First optimize the parameters of king pin,then optimize the toe angle and camber angle.The non-global normalized optimization algorithm NSGA-II was selected.Finally,the joint simulation optimization was used ADAMS CAR and Isight to get the optimized results.After comparing the results,it showed the kinematic parameters of the double wishbone suspension of vehicle with motorized-wheel-drive are nearly reached the level of target vehicle,that is to say the results verified the availability of this optimization method.