Research On Active Safety Technology Of Counterbalanced Forklift

Counterbalanced forklifts has become more and more widespread,and the working environment has become more and more complex.The research on the safety performance of forklift trucks and the active safety control of forklifts is also increasingly important.Based on the establishment of forklift virtual model and mathematical model,two lateral stability control strategies are proposed,and the lateral stability control is carried out to reduce the probability of rollover of the forklift and improve the safety of the forklift under extreme conditions.The main work of this disserationis is as follows:(1)Based on ADAMS,a virtual prototyping model and a dynamic mathematical model of forklift truck were established.The structural characteristics of the forklift truck and the mechanism of lateral instability were analyzed.An anti-roll hydraulic cylinder was designed as the actuator of lateral stability control to provide lateral support force.(2)A method of lateral stability control based on lateral load transfer rate is proposed.The lateral stability control of the forklift is divided into two stages according to the lateral load transfer rate.When the lateral load transfer rate is greater than the secondary threshold,the cylinder is locked;fuzzy control is performed when the lateral load transfer rate is greater than the first-order threshold and less than the second-level threshold.(3)A method of lateral stability control based on T-S fuzzy neural network is proposed.The method of lateral stability control is divided into upper identification layer,middle control layer and lower execution layer.upper identification layer: Based on TS fuzzy neural network forklift driving state is identified,the forklift driving state is divided into three states: absolute safety,safety boundary and danger.The lateral acceleration,load and fork height are taken as input,the forklift driving state is taken as output;middle control layer: different control strategies are adopted according to the forklift driving status identified by the upper layer;lower execution layer:the antiroll-hydraulic cylinder is performed according to the control command from the middle layer.(4)A fully hydraulic synchronous steering control system was designed.A model of full-hydraulic synchronous steering system was established based on Matlab/Simulink.Steering PID control was performed to achieve a one-to-onecorrespondence between the steering wheel angle and the wheel rotation angle,achieving high-precision positioning and steering.(5)the circuit schematic diagram of the lateral stability control system of the counterbalanced forklift,PCB plate and prototype design are completed,high-speed serpentine working conditions and European standard dynamic stability experimental vehicle test is experimented.