The Research Of Servo-valve Characteristic Test Technology Based On Virtual Instrument

Electro-hydraulic servo valve is widely used in aerospace and other fields; it is the core component of electro-hydraulic servo control system. The dynamic and static performance of servo valve have a great affection to the performance of servo system. Because of this, the servo valve manufacturers need to apply a strict performance test on the servo valve. But now most servo valve manufacturers take the dynamic and static performance test manually, so as the data processing. The testing efficiency and accuracy is not high, which is determined by human factors.The article focused on the problems found in the old servo valve test system. And further research was down on the key technologies of servo valve performance test. It designed a new servo valve performance test system to make experimental study.The article introduced the hardware design of the test system. It included the overall program, test bench body, hydraulic system design. The system signal acquisition and control circuit design was also dealed. The system has an upper and lower computer structure. The computer and the control & acquisition module share out the work and cooperate with one another. Then, the article described the design of the system software based on visual instrument.After built the servo valve test system, the paper focused on the key technologies of electro-hydraulic servo valve performance test. For example, a new method of high precision servo valve dynamic performance measurement based on Zoom FFT algorithm, a high-precision servo valve drive signal generator based on microprocessor and DDS technology, and the servo valve sampling and filtering technology.By experimental study, we draw the conclusion that the new method can solve the issues found in old testing system, and the repeatability accuracy of the new system is within 5%.