Research On Rollover Criterion And Anti-overturning Control Of Container Straddle Vehicle

With the rapid development of smart ports and automated terminals,container straddle trucks have become essential handling equipment for ports,and are often used in ports and logistics yards.However,due to the characteristics of straddle trucks such as large mass,high center of mass and narrow wheel pitch,especially in turning,emergency braking and bad weather conditions,It will lead to a significant reduction of vehicle stability and rollover accidents,resulting in huge economic losses.Preventing rollover of straddle vehicles is an important challenge in the research field of straddle vehicles technology.The research on related issues is insufficient,and an effective control strategy is urgently needed to deal with this problem.This paper’s primary research topics are as follows:First of all,in order to study the rollover mechanism of straddle vehicles,it is necessary to establish an accurate dynamic model.Aiming at a company’s 8-wheel container straddle vehicle as the research object,the system dynamics of straddle vehicle under Ackermann steering was analyzed.According to the dynamics principle,a three-degree-of-freedom roll model and a linear tire model were established.Considering the structural characteristics of straddle vehicle,the whole vehicle parameters were calculated and analyzed,and the dynamics model of straddle vehicle was established.According to the changing speed and tire Angle as input,the influence of the two conditions of step and hook on the rollovers stability of straddle vehicle was simulated and analyzed.Secondly,the influence of the inherent parameters of the straddle vehicle is analyzed.Including the position of the center of mass of straddle vehicle,vehicle speed,vehicle mass,suspension roll stiffness,suspension equivalent damping and tire side stiffness were analyzed,and the influence of different parameters on the rolover stability of straddle vehicle was obtained,which provided a theoretical basis for the parameter setting optimization of straddle vehicle in the future.Then,a rollover time warning algorithm is designed.The rollover stability coefficient was selected as the observation index and the discriminant index was the lateral load transfer rate.Based on the simulation results of the observed model,the LTR threshold is determined.Through MATLAB/Simulink simulation software,the rollover time warning model was established based on the established straddle vehicle dynamics model,and the rollover warning algorithm of straddle vehicle was proposed.The simulation is carried out under the step and hook conditions,and the LTR output curve and TTR output curve are compared to verify the validity and correctness of the early warning algorithm.Finally,the control strategy of anti-rollover of straddle vehicle with differential braking is proposed.An analysis and study of the PID principle and fuzzy control is conducted,with fuzzy PID control being employed as the fundamental algorithm for differential braking.A novel fuzzy controller is then fashioned.