Excavators Load Independent Flow Distribution System Based On Co-simulation Of Machine Fluid Dynamic Characteristics

Hydraulic excavator is one of main types of construction machinery. As a typical control mode of the hydraulic excavator,Load Independent Flow Distribution system is used more and more extensive. However, there is a load-sensing(LS) feedback control loop in the hydraulic system,so it is easy to produce LS feedback oscillation, and less stable.To analysis the dynamic characteristics of the system, and get improvements that weaken the LS feedback oscillation of the system and improve the response speed of the system,which has important practical significance.The main research work as follows:Building the three-dimensional solid model of excavator working device with Pro/E software and importing into the dynamic simulation software ADAMS have successfully established a dynamic simulation model of hydraulic excavator working device. And the correctness of the model is verified by the comparative analysis between the result of the simulation and the design value.It also analyses the internal construction's principle of main components and the basis of building model. The application of AMESim establish a simulation model of load-independent flow distribution system.This article also describes the principles and the use of co-simulation software ADAMS and AMESim. Through the connecting of dynamic model of excavator working device with the hydraulic system model by co-simulation module, we can obtain the co-simulation model.The correctness of the co-simulation model is verified through the comparative analysis between the actual measurement and the co-imulation results of single action and compound action when the excavator is in no-load condtion.The co-simulation model is used to simulate operations of the hydraulic excavator when it is in no-load condtion,in excavating condtion and in back-bit operating condtion.,and the influence that three different condtion cause to the dynamic characteristics of the system is obtained.Take the excavating condtion for example, improvements that weaken the LS feedback oscillation of the system and improve the response speed of the system have been got through simulation,which provide a basis for setting parameters of LS valve.In short, the thesis for the research of load independent flow distribution system's dynamic characteristics of hydraulic excavator provides a complete set of theories and methods and it also provide several advanced and novel ideas.