Optimization of a Five-DOF Road Vehicle Suspension and the Hump for the Comfortable Ride and Speed Control

摘要

Vehicle suspension systems are designed to make a ride comfortable at all the speed ranges of the vehicle, while the hump profile should provide an excitation to make riding conditions uncomfortable to the drivers when exceeding their designed speeds. To achieve these objectives simultaneously, the maximum acceleration of the driver at speeds greater than the hump designed speed is minimised to obtain optimum damping ratio of the suspension system. Further the maximum acceleration of the driver at the hump designed speed is minimised to obtain optimum hump dimensions. This process is repeated alternately, under adequate constraints. A five-DOF half car model of a typical road vehicle is taken for the alternate optimisation of the hump dimensions and the damping ratios of the suspension system. The results of optimisation show that there is a certain safe speed range for comfortable ride while passing over the hump and if the driver does not keep speed of the vehicle in this range then excessive uncomfortable maximum acceleration is experienced.