A Research On Anti-rollover Control Systems Of Three-axle Vehicle Based On Dynamic Model

Heavy truck plays a vital role in the national life and infrastructure,because of its high center of mass position and relative body weight and large volume, wheel track height too narrow, so easy to cause rollover accident and huge losses of li fe and property. And in all kinds of traffic accident, the heavy duty truck rollover accidents increase year by year. Seriously restrict the development of road transportation industry in China.In this paper,reference on the basis of the related research results at home and abroad, for the purpose of improvement of heavy vehicles roll stability. Key to prevent rollover control system research, mainly includes the following several aspects:Simplified model to establish the low degree of freedom of three-axis vehicle, on the basis of combining genetic algorithm and Levenberg Marquard(L-M) numerical optimization algorithm, based on the Adams simulation under the step steering condition data, identify the vehicle model in the former, middle and rear axle sha ft of cornering stiffness. And then through the step condition, the identification results are simulation. The simulation results show that the identification method is adopted to establish the dynamic model is relatively accurate, the motion of the vehicl e better simulate the vehicle’s basic movement characteristics of the transient and steady state.Applicating basic theory of multi-body dynamics calculation, on the basis of multi-rigid-body system dynamics, consider the suspension K&C characteristics to establish a team with characteristics of high accuracy for the rear axle twins three-axis vehicle nonlinear dynamic model of 26 degrees of freedom.With the improved iterative algorithm to solve the differential equation, through the comparison analysis with ADAMS and Truck Sim, found that the simulation precision is higher than the Truck Sim, speed of computing in ADAMS. In approaching nonlinear motion, and the model can also be used for simulating the vehicle movement state.Stability control based on the traditional way of thinking, uising of lateral acceleration as evaluation index, the rollover of two degrees of freedom vehicle model established based on the ideal linear quadratic(LQR) rollover prevention control strategy; Based on the LQR algorithm, firs t of all, establish offline feedback control coefficient; Once the lateral acceleration of the vehicle more than threshold method, get through look-up table fast optimal additional yawing moment; Then,using differential braking control of the wheel brake p ressure,implementing the corresponding control torque, the vehicle stability returns. Through to conditions of the simulation results show that the side turn active control system for vehicle under normal operation has no interference.The vehicle will roll over when the side tumbling stability.This system has a positive effect to prevent the vehicle rollover.