Study On Vibration Suppression For Telescopic Boom System Of Aerial Work Vehicle

As a kind of engineering vehicle, aerial work vehicle is widely used in many occasions, such as civil engineering, equipment maintain and rescue missions. Since aerial work vehicle is mainly used to carry personal, high stability and security are required during the movement of its boom system. Therefore, it is an important mean to achieve such object by realizing vi-bration suppression for the boom system of aerial work vehicle in its operation.Based on the study of vibration suppression on flexible boom, the vibration behavior of boom system of telescopic boom aerial platform is studied as a study object, using vibration mechanics and control engineering theory. Feedback control loop is designed in the control model of boom system in order to control the vibration at boom tip. Main finished work and researched contents are as follows:(1) Based on the beam bending vibration theory, the dynamic equation and boundary conditions of homogeneous beam model with tip mass are acquired. The inherent frequencies and corresponding vibration modes of the system are obtained by numerical methods. An or-thogonal space is defined based on the orthogonality of vibration modes, the system vibration equations are obtained in this space. Such procedure is used for step beam model to simulate the boom system of telescopic boom aerial work platform, and to acquire the vibration equa-tions in the orthogonal space. The state space expression of system with luffing angel of boom as system input is obtained.(2) The working conditions causing boom vibration are analyzed, especially the rela-tionship between vibration response at boom tip and the variation of boom luffing angel. Concentrated mass at boom tip, section area and section inertia moment of boom are consid-ered as analysis variables of boom system. By the mean of variable control, the effect of these variables on the inherent frequencies and vibration modes of boom system, response at boom tip, such as angel displacement, velocity and acceleration are analyzed.(3) Using pole placement method and linear quadratic optimal control theory respective-ly to calculate feedback gain vector and to design feedback loop. Vibration active-control for boom luffing is simulated in Simulink. The effect of vibration suppression and trajectory tracking at boom tip are compared between two methods.(4) The function relationship between boom luffing angel and luffing mechanism is ob-tained. The luffing cylinder is considered as actuator to suppress boom vibration, using cylin-der flow rate as control variable of hydraulic system. A detecting plan is designed. The state variables of boom system are represented by measurements, so that they can be detected indi- rectly. A test plan to verify the effect of boom vibration suppression is designed, including hydraulic system and detecting system.