Research On Power Limiting-Load Control System Of Hydraulic Grab

As the national economy is increasing,water conservancy construction, urban construction, national defense construction and other infrastructure is found sequentially.People-oriented awareness and environmental conservation aer in constant reinforcement.All of those made underground diaphragm wall has been widely application and development. Hydraulic grab,as a kind of excavation of underground continuous wall construction machinery are widely used.However,hydraulic grab usually work in harsh environments,load aways change in a wider range.This will have a big effect on power matching of engine and variable displacement pump.Once the power matching broken down,the engine will deviate from the best working point,which will lead to lower energy use efficiency.If the load mutation,variable capacity pump absorption power will be more than the output power of engine,the engine turning will descend and even the engine flamed out.This will seriously affect the normal use of hydraulic grab and construction safety, and the driver’s working condition and construction schedule.In allusion to the power matching problem of hydraulic grab, the following work are finished in this paper.The development and the present situation of hydraulic grab at home and abroad are expounded in this paper; the structure of hydraulic grab, the principle of construction and the operation process are introduced;the current research status of the load-limiting control is summarized.The power system of hydraulic grab composed of engine and variable displacement pump is analyzed;the performance characteristics and the electronic control technology of the engine are analyzed; the variable displacement pump control mode is studied;the constant power control and load sensing control technology of A8 VO variable pump are studied mainly.The matching principle of engine and variable displacement pump is studied;the limit load control principle is expounded;the dynamic adjustment process and the realization of the load-limiting control of A8 VO variable displacement pump is studied mainly.A kind of Single Neuron PID control algorithm based on rotational speed feedback is found,and thecorresponding controller is designed;a co-simulation of power limiting-load control system based on AMEsim and MATLAB/Simulink is made to prove the previous theory.Taking the XG450 D type hydraulic grab as the experimental platform to prove the previous theory is is entirely feasible.