Research Of Handing Stability Performance And Optimization Of Steering Mechanism On Multi-axle Vehicle

As an important index to evaluate vehicles, handing stability performance, not only doesit affect difficulty of drivers’ controlling, but also is related to safety performance in processof driving. Today, with project constructions becoming increasingly onerous, researches onhanding stability performance of multi-axle heavy-duty trucks have been the main trend.In this paper, based on consulting a large number of literatures, research situations ofdomestic and foreign experts or scholars on heavy-duty trucks’ handing stability performancewere summarized, through which evaluation methods of handing stability performance weredefined and ways of thinking for the following studies were clarified. In addition, turningprinciples of two-axle vehicle and multi-axle steering vehicle were respectively introduced.By using the Lagrange equations, linear three degree of freedom control model of multi-axlesteering vehicle was deduced. According to these, the theoretical bases for establishingvehicle model and simulation tests were provided.The modeling process of a five-axle heavy-duty truck with double-front-axle steeringwas highly introduced in this paper. By using virtual prototyping technology, the vehiclemodel was established in ADAMS/Car, including the establishment of suspension, steering,body, cab, power-train and tire subsystem. Constraint analysis, leaf-spring stiffnessverification of balanced suspension, vehicle static balancing analysis and parallel wheel travelanalysis were carried out to the assembled vehicle model, through which the rationality andaccuracy were verified. In ADAMS/Car, according to the national standards for experimentalcontents of handing stability performance, step steer, impulse steer, cornering with steerrelease, steady static circular and pylon course simulation tests were carried out to the model.The experimental results indicated that the model’s transient response characteristics werebetter and its handing stability performance was basically conformed with the request ofnational standards. Then, the influence of different positions of centroid on handing stabilityperformance were discussed, which indicated that handing stability performance would beimproved by appropriately reducing the height of centroid and shifting forward the centroid.Finally, the optimization of steering swing arm mechanism and steering trapezium mechanismin double-front-axle steering mechanism was conducted. Based on the results of optimization,the vehicle model was modified and improved. The simulation test was carried out again toindicate the handing stability performance was improved.The theoretical reference for designing steering mechanism and improving the handingand stability of real vehicle was provided by the researches on handing stability performanceof the vehicle model and the optimization of steering mechanism in this paper.