Transverse Stability Of Tractor Semi-Trailerbased On Rear Steering Analysis And Control Research

Due to its complicated structure and high center of mass position,the traditional semitrailer trains in the middle of high-speed steering in acute steering,emergency braking or high-speed cornering,the tractor and semi-trailer are connected by the fifth wheel,Semi-trailer lateral acceleration is too large,easy to damage the lateral stability,resulting in yaw,flick,folding or even rollover and other serious accidents.In summary,the transverse stability of semitrailer trains is of great research value.In this paper,the semi-trailer trains on the basis of the proposed steering wheel on the basis of the software simulation method of research and analysis of semi-trailer trains stability of the problem.The simplified mathematical model which can describe the motion characteristics of the train is established by analyzing the characteristics of semitrailer train movement.The simulation model was established in Matlab-Simulink and the simulation model was established in Trucksim.The dynamic model was established to validate the kinematic characteristics of semi-trailer trains.Based on the simplified kinetic model which can describe the kinematic characteristics of semitrailer trains,the trajectory following control objectives of the semi-trailer axle center and the fifth wheel are achieved,so as to improve the transverse stability of semitrailer trains.On the basis of analyzing the deviation of the semi-trailer axle center point and the fifth wheel trajectory in the ground coordinate system,it is necessary to transform the deviation analysis from the ground coordinate system to the relative coordinate under the semi-trailer coordinate system.The control system can make the decision based on this deviation Angle of wheel turning.In the rear wheel steering control strategy using the equivalent synovial control,switching control to ensure that the system state does not leave the synovial surface.On the basis of establishing the control strategy of the rear wheel steering with the equivalent synovial control,the difference between the PID control and the equivalent synovial control is compared and analyzed.The effect of the equivalent synovial control on the transverse stability of the semitrailer is better than PID control.The control effect of semi-trailer with semi-trailer steering control and semi-trailer without rear axle steering is analyzed under single-line and double-shift conditions respectively.Based on the analysis of the deviation of the semi-trailer trains from the center of the axle of the rear wheel steering control axle to the fifth wheel,the control strategy to improve the transverse stability of the semi-trailer trains in and out of the corners is studied.The results show that the axle of the semi-trailer does not turn when the train is in the corner and the steering angle of the axle of the semi-trailer is not changed until the angle of the train is less than a certain value.The fifth round of the track deviation,and reduce the lateral acceleration to improve the lateral stability of the train.