Dynamics Analysis and Experimental Research of a Certain Type of Pump Car Arm Frame System
|School||Wuhan University of Science and Technology|
|Course||Mechanical and Electronic Engineering|
|Keywords||arm frame system multibody dynamics union simulation vibration reducing|
Concrete pump which can combine level transmission with vertical transportation of concrete with the help of the arm frame system is special machinery equipment for transporting concrete. The concrete pumps have some advantages such as flexible, simple construction procedure, high efficiency, and high pouring quality and so on and its biggest advantage is that it can easily convey concrete vertically, for example pouring concrete on high buildings, highway, bridges, dams and underground engineering and so on. Concrete pump has caused wide public concern due to the above advantages and has gradually become the essential machinery equipment in project construction process. However, when concrete pump truck working, the arm frame system, to some extent, will have low frequency vibration which is bad to accurate positioning of arm frame end hose and will accelerate the fatigue damage of arm frame system.This paper takes 37 m pump car arm frame system in a engineering machinery company as the research object, treats arms frame as manipulator system, uses the multibody dynamics theory, adopts the method of combining hypothesis modal method and the Lagrange equation to deduce dynamic equation of rigid mechanical arm and flexible manipulators. Because arm frame is driven by hydraulic cylinder, the problem of coupling effect between the hydraulic cylinder and mechanical arm, borrows the concept of Jacobian matrix in robot kinematics, and gives the specific compute method. Solve dynamic equation of rigid mechanical arm and flexible manipulator, and compare difference when reflecting arm frame kinetics characteristics, grope for the motion characteristics of the mechanical arm system, and borrow ADAMS software to have a comparative analysis. In order to further consider effects of arm frame hydraulic system, we use AMESim software to modeling arm frame and hydraulic system. By calling the Planarmechanical module and Hydraulic module of AMESim software, we realize joint simulation between arm frame organization and arm frame hydraulic system. We take 37 m pump truck in an engineering machinery company for experimental test, contrast the measured curve and simulation curve, and verify the rationality of the model. When pump truck working, there will be a certain degree arm frame vibration problems, this paper also explores how to restrain vibration of the end of pump car arm frame, considers the PID control and neural PID control applied in restraining vibration of the end of pump car arm frame, employs MATLAB software and AMESim software to realize the union simulation, uses the existing equipment in the laboratory, and simulates active control experiment of the end of arm frame vibration.Through analyzing simulation results and experimental results, we verify the rationality of simulation model and better effect for reducing vibration of nerve PID control strategy. This paper makes some significance for further improving concrete pump truck arm frame system and suppression research on arm frame vibration.