Towing Vehicle Hydraulic Drive System Adaptive Control Strategy

The purpose of the construction vehicle draw dynamics is to improve the adaptive capacity of draw when the vehicle works under the variable load condition , thus optimize the vehicle performance , realize the overall automation and intelligent , one of its key content is research the control strategy of closing type displacement pump-displacement motor system, its key purpose is through hydraulic system varying function making engine keeps static or sub-static operating mode under greater variable load .At first, this paper analyzed each characteristic of the diesel engine and hydraulic pump, and proposed the ideal control goal when the engine and hydraulic pump system jointly working, then put forward static control strategy which can realize the control goal of variable pump. Secondly analyzed the characteristic of the displacement motor, and compare the difference of the displacement motor control between pressure coupling and flow coupling system, put forward three static control methods of displacement motor. After that, build up math model of closing type displacement pump-displacement motor system , Have joined the model reference adaptive loop to the existed mathematics model of the motor control pump, and structure the simulation model based on Matlab/Simulink, taking parameter from some type -hydraulic test-bed as an example, to carrying on simulation, and obtain better dynamic performance under variable parameter.