Study On Lateral Stability Of Balance Heavy Forklift Truck Based On Phase Plane And Tilting Control

The research object of this project is a type 3T balanced weight forklift which is developed jointly with the enterprise.Forklift as a typical engineering vehicle for carrying goods.The application field is extensive as in the logistics,the express delivery station,the port,the warehouse and so on.However,it is easy to turn over in the work to cause damage to people and goods due to the structure of the forklift.The incidence of accidents caused by side-tipping has always been at the top of forklift accidents.Therefore,this paper mainly studies the transverse stability of forklift,and studies the influence of the safety of the cargo fork on the stability of the vehicle.The aim is to improve the safety performance of forklift stability and reduce property loss and casualties.The content of this study list as below:(1)Dynamitic model of the counter balanced fork lift truck is established,Tire stress analysis,front and rear axle load and tire vertical force analysis and side turn condition judgment should be accomplished.The principal factors which impact on lateral stability of the counterbalanced lift truck should be comprehensive analyzed.(2)A new research idea about analyzing lateral stability of the forklift truck is proposed.Linear two-freedom forklift model is established according to the knowledge of vehicle dynamics and kinematics.Centroid lateral Angle-velocity phase diagram of center of mass is simulated by Simulink depended on two degrees of freedom differential equation.The stability region divided by the phase trajectory of the phase plane is taken as criterion of researching and controlling lateral stability of forklift truck.(3)Actuator of forklift roll Control is three-link.Horizontal hydro-cylinder not only can solve the problem of installation space and manufacturing cost,but also attitude adjustment of the heeling forklift.Roll grading control strategy of lateral stability counter of balanced fork lift truck is put forward.Forklift heeling can be divided two classes,one-level heeling and two-level heeling.When forklift is in one-level heeling,fuzzy control with variable region of one-level works,when forklift is in two-level heeling,fuzzy control with variable region of two-level takes effect.(4)The importance of the studying mast of fork truck is expounded.When the load or height of center of gravity increases,the forward Angle and the speed of retroversion decreases and vice versa.This strategy can effectively solve and reduce the occurrence of side-turning accidents,reduce accident rate caused by subjective error of driver.(5)Real vehicle tests verify the three-link and roll grading control strategy can enhance lateral stability of forklift.