Design Of Test And Control System For Combined Hydraulic Instrument Based On LabVIEW

Hydraulic transmission experimental teaching is an important component of hydraulic transmission teaching. Hydraulic instrument is the hydraulic transmission equipment commonly used experimental teaching, and it is a combination of theory and practice. The control of the hydraulic loop and the test of relevant parameters is the focus of hydraulic drive experimental teaching. And Virtual Instrumentation is today's mainstream of test and control technologies. The use of advanced Virtual Instrument technology gradually instead of the traditional methods of test and control in the field of hydraulic test and control has broad prospects.In this paper, a test and control system, that is used in the combined hydraulic, instrument have been developed based on the Virtual Instrument with LabVIEW software. This paper introduces the hydraulic instrument control system's hardware components as well as relevant principles, and completed a hydraulic instrument monitoring system hardware and software design. The effective control for the solenoid pilot actuated valve have been achieved in the hydraulic loop through the digital output signal control; Through the acquisition of the digital input signal, the full application of the switch element in the hydraulic loop control, time and other aspects have been achieved. The acquisitions of flow speed and rotate speed have been realized through the effective use of counter. The acquisitions of pressure and load analog signal parameter have been realized through the analog input signal acquisition. And the realizations of the data storage, curve drawing, print, and other function have been achieved. The control of components and data acquisition in the majority of experimental test and control systems are in the same way, so a number of separate SubVI have been compiled for these functions with the use of modular programming, and the SubVI would been called in any experimental modules of the system. With the use of the SubVI, some quasi-experimental test and control system have been completed for the characteristics of hydraulic pump, the dynamic and static characteristics of relief valve and the characteristics of throttle control loop. And the differential loop, the order loop, pressure regulator loop, and other quasi-experimental control system have been achieved. And they are validated finally. Results show that the design of the monitoring system is reliable and easy to operate. It can not only meet a few common experimental verification of the test, but also meet the innovative experiments designed by students. The system is versatile, flexible and extensible. And it is a good technology platform for students' quality training.