Study On Virtual Test Of Car Ride Comfort

Vehicle ride comfort is one of the prime performances of modern high-speed and high-comfort vehicle. In all increasingly competitive situation, the introduction of new technology and new methods has become the main way to improve the product competitiveness. Virtual prototyping technology integrated modeling and simulation technology in one, which can shorten the development cycle, reduce development costs, improve product quality, so as to achieve the purpose of improving the competitiveness of products. Moreover, it is also one of the most important indices that determine the vehicle whether it has the advantage in the market competition. As rapid progress of computer technology and application of virtual reality technology, we can create a 3D vehicle model and a virtual proving test rig in the computer, make the vehicle model run on the virtual testing road, then evaluate its performance.Taking a car of certain model as an example, the multi-body dynamics models which include front suspension, rear suspension, powertrain, chassis, steering system, tires and the random road model are established with the vehicle dynamics analysis module ADAMS/Car in the multi-body dynamics software of ADAMS and whole vehicle model is established based on these models. According to the national standard, the model of the vehicle was analyzed by the pulse input test and random input test of the ride comfort. The results showed that the maximum acceleration of the vehicle was far less than 31.44m/s2, which was harmless for the driver'S health, when the vehicle drove through the triangle under the different speeds.The random excitation of the four wheels is used as the input of the system. The changing rule of three acceleration power spectrum density function of person-chair system in the frequency domain in different speed and road is simulated by means of ADAMS. The results show that the higher the speed of the vehicle is and the worse the road condition is, the greater the vibration response of the person-chair system is.The affect of the vehicle parameters, such as the stiffness and damper of the suspension and the seat, is analyzed. Finally, the dissertation optimizes the suspension parameters such as the stiffness and damper according to similar D-Optimal design. Regarding the root mean square value of driver's acceleration as target, the experiment optimization design was carried out to lower the value. The results show that the vibration response of the model after optimization is lower than that before optimization.