OPTIMAL PARAETERS OF SUSPENSION SYSTEM FOR IMPROVING ELECTRIC VEHICLE RIDE COMFORT AND ROAD FRIENDLINESS

In order to improve the Electric vehicle's ride comfort and road friendliness, a quarter electric vehicle vertical dynamic model under the combination of two excitation sources such as electromagnetic excitation in motor and road surface roughness excitation is established for searching the optimal design parameters of EV suspension system using genetic algorithm and two objective functions such as the weighted root mean square (rms) acceleration of the vertical vehicle body (aw) according to the international standard ISO 2631-1 and dynamic load coefficient (DLC). The optimal results indicate that the aw and DLC values reduce by 12.71% and 10.36% in comparison with the original suspension system when the vehicle operates under the combination of two excitation sources. Finally, the optimal design parameters of EV suspension system are evaluated under different operating conditions of the vehicle and the evaluation results indicate that the optimum performance of the EV suspension systems has better than the original suspension system