Analysis Of Concrete Mixing Truck Rollover Dynamics And Research Of Anti-rollover Control Algorithm

With the number of mixing trucks increasing,traffic accidents increase year by year which not only cause huge economic losses,but also endanger people's lives.Compared with other heavy haul freight vehicle,in addition to large carrying capacity and high center of gravity,the mixing truck maintains state of mixing and stirring in the conventional transport conditions,which causes centroid offset left.Especially in the process of steering,centroid of the mixing truck produce a greater shifting,meanwhile the lateral acceleration and the heeling angle will easily exceed the rollover limit,resulting in the mixing truck turn on its side in the mixing effect.Therefore,it becomes vital to study the stability and safety of the transportation of the mixing truck.In this paper,based on basic structure and mechanism of the mixing truck and the mixing cylinder,by means of the mechanics analysis of the mixing cylinder and analysis of the mixing truck rollover factor,the centroid position of the mixing cylinder is calculated in the static state,stirring state,steering state,which determines the mixing truck centroid offset under the condition of steering.By establishing rollover dynamics models of the critical rollover state under the condition,adopting actual parameters of a mixing truck,Matlab/Simulink software is used for analyzing effect of loading rate on critical tipping angle,influence of turning radius and transverse slope angle on critical rollover velocity,rollover steering angle and turning radius of the load ratio,relationship between steering wheel angle and turning radius,which indicates ground right turn transportation conditions of full load are most prone to rollover.By analyzing the mechanism of the roll yaw stability,the coupling effect of yaw motion on roll motion is determined.Selecting the differential braking control strategy,based on the principle of optimal control and PID,anti rollover control system of a mixing truck is established by using Matlab/Simulink software.Meanwhile,the agitator truck simulation model is established by using Trucksim and CATIA software.Three different speed,including 70km/h,50km/h,30km/h,is selected to compare and analyze variation curves of the lateral acceleration,the yaw rate,the heeling angle by Joint simulation before and after control in the four simulation test conditions,including fishhook condition,double lane change conditions,sinusoidal conditions,angle step condition,which shows that the most dangerous condition of the mixing truck is the fishhook condition,and that wrenching the steering wheel should be avoided during the driving process,and the steering wheel angle should be changed slowly.The research results show that when the roll motion is becoming increasingly fierce,reaching a certain extent,the controller starts to be triggered,and that after the control,and lateral acceleration,yaw rate,the heeling angle associated with the roll motion reduces significantly,which indicates that differential braking has good control effect,and that the controller can realize the anti-rollover control on the mixing truck,and has a certain reference significance for reducing rollover accidents and improving road safety.