Anti-overturn Control Of Unmanned Straddle Carrier

In recent years,many large container ports are gradually transforming towards the implementation of container terminal automation and semi-automation.With the opportunity of automated transformation of container terminals,container straddle carriers have once again entered people's sights by virtue of their high efficiency in loading and unloading,saving fuel costs and maintenance costs.The container straddle carrier has a large inertia,a high center of mass,and a large mass.These characteristics make the vehicle particularly prone to rollover during the driving process,especially during the steering process.The container straddle carrier is developing towards the intelligent stage at present,but it is still in its infancy,and there are not many related studies.As a key problem in the current technology of container straddle carriers,it is urgent to develop a control scheme that can effectively solve this problem.This paper summarizes the research results of domestic and foreign scholars in the field of vehicle rollover.Taking the 8-wheel independent steering straddle carrier as the research object of this paper.Analyze and study the principle of rollover of straddle carriers.In this paper,differential braking technology is applied to the straddle rollover prevention field.The specific research contents are as follows:This paper analyzes the dynamics of a straddle carrier.Based on the two-degree-of-freedom and three-degree-of-freedom models commonly used in automobile models,this paper combines a linear tire model to establish a straddle rollover model.The straddle carrier rollover model is constructed and simulation verification are carried out on the MATLAB/Simulink platform.The advantages and disadvantages of commonly used vehicle rollover discriminant indicators are analyzed,and the straddle vehicle roll safety factor and the lateral load transfer rate are selected as the traverse vehicle rollover discrimination indicators.The simulation results of LTR and C_t are compared and the LTR threshold is calibrated according to the threshold of C_t.Select LTR as the control variable for the controller.This paper analyzes the effect of braking force on the motion state of a straddle carrier during single-wheel braking,establishes a braking force distribution strategy.The differential braking method is used to correct the running state of the straddle carrier,and the overall scheme of the straddle differential braking anti-rollover system is designed.The advantages and disadvantages of commonly used algorithms are analyzed,and Fuzzy-PID control is selected as the control algorithm of differential braking.The Fuzzy-PID controller is designed with LTR as the control variable,and the controller model is built in the MATLAB/Simulink platform.The anti-rollover control system established in this paper is simulated and verified.