Design And Research Of The Electro-hydraulic Proportional Loading System Based On LabVIEW

Based on the hardware system of electro-hydraulic proportional pressure-flow test-bed in the mechanical-electro-liquid whole laboratory of Chang'an University,the research takes the advantages of computer and applies the control theory of the fuzzy PID control theory to the research and development of the control system of electro-hydraulic proportional loading.The usage of G language in the software of LabVIEW completes the programming of the test rig load control system and achieves the collection and management of related data and the load of control signal,which verifies the feasibility of using LabVIEW to design load control software and to apply fuzzy PID control theory to the electro-hydraulic proportional loading control system and the design of the reliability and validity.Following are main works of the thesis:1.Based on the existing test-bed in the laboratory,the paper analyzes the composition of electric-hydraulic proportional loaded system and the working principle of electro-hydraulic proportional throttle valve and electro-hydraulic proportional flooding valve and then selects the hydraulic parts.Finally the hardware of the electrical part is selected.2.In the research,it is the electrical signal input that controls the torque on the input axis of the secondary component.In order to study and analyze its control performance,mathematical modeling is carried out for the main mechanisms and then the mathematical models of proportional overflow loading system and proportional throttling loading system are obtained,which are not simplified.Finally,simplified mathematical models of proportional overflow loading system and proportional throttling loading system are determined.3.Through analyzing the advantages and disadvantages of different PID control,the fuzzy PID control technology is adopted to this research's controller.Then the simulations of the electric-hydraulic proportional loaded system with fuzzy PID control and the other one without fuzzy PID control are established and added in MATLAB and SIMULINK modules.It shows that joining of the fuzzy PID control greatly eliminates the overshoot of system and improves the response speed,stability and dynamic characteristic.4.Based on the software platform of the LabVIEW,the controlling software is designed for the electro-hydraulic proportional valve loading control system on the test-bed,including the design of flow chart of the program,the data collection and data management of LabVIEW.At last in the LabVIEW the application of graphical language achieves the fuzzy PID control and improves the control performance of the system.