Research On Electro-hydraulic Automatic-leveling System Of Aerial Work Vehicle With High Adaptability

The aerial work vehicle as a large-scale construction machinery equipment is widely used in ships, traffic, landscape maintenance, municipal construction, power protection and other various industry and place.It is an emerging technology industries, has broad prospects for development. And the leveling technology is one of the key technology of the aerial work vehicle. With height increasing of aerial work vehicle, the more strict for the leveling system of all kinds of performance requirements. Therefore, this paper analyzes the leveling characteristics of the aerial work vehicle, the characteristics of system based on valve-controlled asymmetrical electro-hydraulic positioning closed-loop control with four-channel actuators. Through control strategy analysis, theoretical modeling, simulation and experimental study of the automatic leveling system, achieved a rigid platform for Aerial work vehicle in the precision range of fast, stable adjustment. The research has following main contents:Firstly, On the basis of consulting numerous related literatures and reference materials at home and abroad, state the development of aerial work vehicle and the technology of electro-hydraulic proportional leveling. Taking Hangzhou Aizhi engineering vehicle Co.Ltd SN15B series aerial work platform as background, according to its performance index, composition and working principle of the leveling system are described in detail, and the overall design scheme of the automatic leveling system is given.Secondly, On the basis of the research on the leveling control method, strategy research, and the analysis of the platform position and orientation characteristics. This paper proposes the use of four switches valve and a electro-hydraulic proportional directional valve joint as control element for leveling system to control the leg lift. And configure two inclination sensor as the platformin inclination detection, the control mode of both position and current closed loop, pressure sensor as auxiliary detector, avoid virtual leg problems. At the same time, the leveling process is divided into multi points of the coarse adjustment and single point of the fine adjustment.Then, Matching the electro-hydraulic leveling system and select the key components, and studying the proportional characteristics of the solenoid switch. Through field measurement, proved that the switch valve has good proportion control performance, proposed to switch valve proportional control is applied to the automatic leveling system of the coarse adjustment.Finally, On the basis of the analysis of the electro-hydraulic proportional system, the mathematical model of asymmetrical hydraulic cylinder controlled is established. And the co-simulation used MATLAB/Simulink and AMESim on the system dynamic response and the leg movement process simulation analysis. This paper designed a high performance level controller, build the test platform and experiments are design to detect the performance of the leveling system with the controller. Proves that the leveling control system designed in this paper is feasible, and it is a solid foundation for the research on the electric-hydraulic automatic leveling control.