Research On Characteristics Of Traction And Loading For Multifunctional Test Bench Of Construction Machinery

Multifunctional test bench of construction machinery on which several working devices of construction machinery are attached can be used to make traction and loading experiments for the study on experiments of the interaction between working devices of construction machinery and handled media. Based on analysizing structures, working principles, functions and usages and parameters of mechanical structure system, hydraulic system, controlling system and testing system of the bench, the paper researches followings mainly:Firstly, based on the working priciple of the towing hydraulic drive system, for example that a blade of a bulldozer is attached on the test bench, the paper researches the dynamic traction characteristics of the one pump-one motor towing hydraulic drive system of the bench, analyzes the hydraulic system and the transmission system, calculating parameters of the transmission systeme. Meanwhile, on the basis of tractive situations, it analyzes forces exerted on the test bench and draws tractive characteristic chart of the bench. Because the hydraulic system of the bench is a secondary regulation system, according to speed regulation property and hydraulic power cotrol theory of the secondary regulation system, it researches respectively constant speed control and constant power control of the hydraulic system of the bench, establishes mathematical models and control workflow diagram, makes simulations of the constant speed control and constant power control and analyzes the results of the simulations.Secondly, it researches loading characteristics of the bench which is used as a load. It analyzes loading theory of the hydraulic system of the bench through the intrduction to the secondary regulation system, respectively establishes mathematical models of the constant pressure variable displacement pump, hydraulic accumulators and secondary element and the whole workflow diagram of secondary regulation loading system, and makes simulations of the constant pressure variable displacement pump and secondary element in different loading ways and with PID control and fuzzy PID control.Thirdy, on the basis of structure, control theory and functions of the controlling system of the bench, it researches controlling program designs of the controlling system of the bench, the contents of program desigens include PLC program design, monitor and control program design of industrial controller and deeply cutting control program design of the blade. Finally, it analyzes dynamic mechanical-hydraulic co-simulation of the bench based on AMESim and Adams softwares. In the method of mechanical-hydraulic co-simulation, with the help of Adams softwares of dynamic simulation and AMESim hydraulic simulation softwares mechanicai models and hydraulic models of the bench are established. Moreover, parameters of the models are determined.The co-simulation of AMESim and Adams are established to realise mechanical-hydraulic co-simulation, using files of software interfaces to exchange data. At last, the simulation results are analyzed to verify correct and availability of the simulation models.