Research On Anti-rollover Control Of Three-axle Rescue Vehicle Based On Differential Braking And Active Suspension

The Three-axle rescue vehicles are more prone to rollover because of their complex working environment,high working speed,high vehicle load,and high center of mass factors.In this study,taking a three-axle rescue vehicle with active suspension as the research object,differential braking and active suspension control are studied with the objective of improving the anti-rollover performance of the three-axle rescue vehicle.In this paper,in conjunction with the NSF regional joint fund project "Research on the dynamics control of high mobility rescue vehicles based on multi-information fusion"(Project’s number: U20A20332),an eleven-degree-of-freedom nonlinear time varying rollover model of the three-axis vehicle is established,and a two-parameter update method of TTR(TPUTTR)is proposed to calculate the TTR rollover evaluation index.The method of calculating TTR rollover evaluation index is proposed.The active suspension controller and differential brake controller are designed to improve the anti-rollover performance of the three-axle vehicle.In this paper,based on the coupling characteristics of the vehicle suspension system and tire forces,an anti-rollover control strategy based on the joint control of differential braking and active suspension for a three-axle rescue vehicle is proposed.Because of the variable road conditions and irregular road excitation of the vehicle,a robust fuzzy PID algorithm is used to build the active suspension controller.The lateral attitude of the vehicle is adjusted by outputting the actuating force of the active suspension.The adaptive model predictive control algorithm is used to build the differential braking controller according to the characteristics that the lateral motion of the vehicle is violent but predictable in the nontripping rollover state.The lateral motion of the vehicle is regulated by generating additional transverse moment through differential braking of the wheels.The two parts of the upper controller and the lower controller together form the adaptive model predictive controller in this paper.The upper controller has parameter estimation capability and state update capability,which solves the control distortion problem of model prediction for nonlinear time-varying systems.The lower controller calculates the actual additional transverse swing torque numerical input based on the selection of the target brake wheel under differential braking control.The paper concludes with simulations on MATLAB/Simulink software for both J-turn and Fishhook steering conditions.The simulation results show that the joint control method can validly reduce the rollover tendency of the vehicle.Compared with the control effect of a single system,the anti-rollover capability of the three-axle rescue vehicle is further improved.