Based On The Hydraulic Excavator Of The Electro-hydraulic Proportional Control System

As one of the main products of construction machinery, hydraulic excavator plays an important role in a variety of construction. In order to improve the efficiency and working properties of the excavator, reduce energy consumption and operating intensity, the introduction of automatic control is imperative. The control system of hydraulic excavator is the key to achieve automatic control and intelligent control. And the use of electro-hydraulic proportional technology in excavator has played a pivotal role in control system. The hydraulic excavator SWE230 of Hunan Sunward Intelligent Machinery Company is put as the object of study in this thesis. The goal is to study the control system of hydraulic excavator.A lot of information and documents are searched in the paper. The domestic and foreign development overview and latest trend of hydraulic excavator control system are described in the paper. And domestic and foreign research results of the controller of hydraulic excavator are collectted. The research of control system of hydraulic excavator is studied in this paper against the features of SWE230 hydraulic excavator. The effect of electro-hydraulic proportional technology in excavator electronic control system is analyzed. The next, from the start with the advantages and characteristics of PWM control, the key technology of electro-hydraulic proportional control in the realization of PWM control has been studied. A complete proportional valve control scheme is proposed, including the research of the key parameters of PWM control technology and slope control. The heating phenomenon of proportional valve is analyzed theoretically, the current feedback closed-loop control is proposed, and PI algorithm is used to adjust bias and stabilize the current. Then, on the basis of the analysis of the overall program of SWE230 hydraulic excavator control system, the hardware and software design is completed. The experimental platform for excavator electronic control system is built. Finally, the controller performance was tested on experimental studies both in the laboratory and workshop. The experiment shows that the controller functions of each module meets the design requirements and has strong anti-interference ability and stability. And it shows that the controller has a good effect to control the electro-hydraulic proportional valve. It establishes foundation for the hydraulic excavator electronic control system.