X31Passenger Car Oversteering Problem Research

In this paper X31prototype car in steady state test with the lateral accelerationincreased oversteer problems appear, in the consulting and summing up a large number ofdomestic and foreign automobile handling stability research foundation as well as thevehicle based on dynamics simulation technology, using multi body system dynamicstheory and research method, based on the multi-body system dynamics simulationADAMS software, collection includes body, powertrain system, suspension system,steering system, stabilizer bar and bushing parameter, hardpoint and car size parameters,mass characteristics and mechanical properties of parameters, then build a completevehicle virtual prototype model. In the building model process, in the full research X31platform chassis structure features, on model made has reasonable of structure simplifiedand the built model assumptions; while through entity built model and test methodobtained has all main parts of size parameter, and physical characteristics parameter andmechanical characteristics parameter, as rubber stiffness, shock absorber damping, andcoil spring stiffness, and tire stiffness and so on, all these flexible parameter are obtainedthrough test rig, it can makes model has a greater precision.After the vehicle model was built, complete the steady state test through the virtualsimulation of vehicle handing stability test, after compare the test results of simulation androad test, verify the correctness of the model. On this basis to build a prototype model, andcomplete the steady state test for simulation of vehicle, evaluation and improvement.Suggest that improve the suspension roll stiffness through increasing the diameter ofstabilizer bar, then can optimize the oversteer characteristic. In accordance with theimproved scheme to produce improved prototype and real vehicle steady state test,through the analysis of test results improved scheme is feasible, thereby reducing thevehicle development risk and cost, so as to meet the expected design goal.