Research on Modeling and Steering Stability Control of Four-wheel Steering Electric Forklift

 

Abstract: Electric forklift is a kind of industrial vehicle that is used to realize the mechanization of material handling. Because its load is relatively heavy and the working space is relatively narrow, the steering characteristics of the forklift are higher than other vehicles. Four-wheel steering (4WS) technology is the most effective active chassis control technology to improve the handling stability of forklifts and improve the safety of forklifts. Compared with the forklift of the traditional steering system, the four-wheel steering system has the characteristics of small turning radius and flexible operation. The four-wheel steering system based on the wire-controlled technology eliminates the mechanical connection between the steering wheel and the steering actuator in the traditional forklift steering system, thereby getting rid of the mechanical structure's constraints on the steering characteristics and greatly improving the design of the forklift. Flexibility. This paper mainly studies the improvement of the steering stability of the four-wheel steering forklift under the classical control method. The main research work of the thesis is as follows:Firstly, this paper combines the TFC35 electric forklift produced by a company to analyze and study the principle and main components of the four-wheel steering system based on the wire-steering technology. Secondly, through the mechanical analysis, a four-degree-of-freedom four-wheel steering forklift dynamic model is established based on vehicle dynamics. The discussion analyzed the factors affecting the handling stability of the forklift. Then, based on the established four-degree-of-freedom four-wheel steering electric forklift model, a four-wheel steering control method based on particle swarm optimization PID is presented, and the particle swarm optimization PID controller designed for the four-wheel steering system is described. Specific design steps. Finally, under the Matlab/Simulink platform, based on the four-degree-of-freedom four-wheel steering forklift model established in this paper, three kinds of control of feedforward four-wheel steering control, traditional rear wheel steering control and particle swarm optimization PID four-wheel steering control are respectively carried out. The simulation experiment is carried out. The simulation results show that the particle swarm optimization PID control four-wheel steering control method has the best comprehensive control effect and effectively improves the steering stability of the forklift. Collapse 