Synthetic Research For Dynamics And Tires Wear Of Some Kind Of Multiaxis-Vehicle With Electronically Controlled Hydraulic Steering

The object of this study is a kind of four axis (8x2) heavy duty truck,which includes three steering-axle composed of the first two axis with hydraulic steering and the third axle with electronically controlled hydraulic steering, designed by some vehicle company. The goal of this study include:To boost handling and stability of tucks, when turning with high speed, by controlling the angle of the third steering axle, in addition to improving the wear resistance of the third axis of the tires; To establish the TDF multi-axle vehicle dynamic model based on the valve-control cylinder, with the theory of vehicle dynamic and hydraulic control system; To contro the objectl systemicly, using threshold controlling strategy combined with PID online setting based on RBF neural network controlling algorithm, with the goal of optimized steering stability and steering wheel wear. After simulating the vehicle dynamic model in MATLAB/Simulink, get the results of time domain response, which belong to yaw velocity, centroid side-slip angle and lateral acceleration, to the first axle angle step under the condition of20km/h low-speed and50km/h high-speed, and their frequency domain analysis with bode diagram.At the same time, contrast the third axle angle time domain response to the first axle angle step, when running steering and parking steering, under three kinds of control-the open loop control, PID control, RBF neural network setting PID control, and evaluate the wear resistance of the third steering axis of the tires indirectly with the instantaneity and overshoot of the third alex steering control.In addition, firstly, to be more convenient to research the steering wheel wear of the third axis (electronically controlled hydraulic steering),create the whole vehicle model of the8x2heavy duty truck in ADAMS/Car. To reduce the amount of lateral and longitudinal slip of the third axis steering wheels, to enhance adhesion ability, to the ground, of the third axis steering wheels, to reduce abnormal wear of the third axis steering wheels, compare and filter out the third axis steering wheels’ initial value of alignment parameters (camber and toe angle), with simulation experiments about wheel beating in the same or counter direction. Secondly, simulate side impact to vehicle in motion the process with lateral loading test; Under the condition of changed cornering properties of the third axis steering wheels, research the third axis wheels’ slippage after improving their alignment parameters; Evaluate wheels’abnormal wear indirectly. At the end, by simulating and analyzing suspension roll angle and stiffness、roll camber coefficient、roll steering coefficient and steering deformation coefficient, research stability and safety of the vehicle when subjected to lateral force in the process of moving.