Design Of Measurement And Control System Combined With Diagnosis For Engine Test Bench

The internal structure of modern missile engine is complex,and its performance index cannot be accurately obtained by aerodynamic simulation and calculation,so simulation test has become an important technique to explore engine performance.Engine’s ground test is a necessary means for engine development.With the help of advanced ground test equipment,the test bench can simulate all working conditions of the engine and check whether the design indexes are realized.The topic of this paper comes from the supporting test facilities built by our institute for engine development and production,which is an important facility of engine test system.Relying on the rapid development of computer technology,this design combines the current mainstream technologies such as integrated measurement and control technology,digital signal processing technology and virtual instrument technology,and strives to create more advanced and intelligent test facilities.The research goal of this paper is the test-bed measurement and control system.The functions of the test-bed measurement and control system include the control of test-bed equipment and engine valves,pumps and motors,as well as the collection,calculation,storage and real-time display of temperature measuring points,pressure measuring points,thrust measuring points,engine vibration signals and speed signals.The measurement and control system adopts integrated design and the most advanced PXI platform at present,which solves the difficulties of many measurement and control points,high acquisition rate and large amount of data.The software adopts object-oriented design language and modular design concept,which makes the measurement and control software developed quickly and easy to maintain,and realizes the functions of equipment maintenance,engine test and test piece fault prediction and diagnosis.Through the analysis of error sources and the calculation of uncertainty,the process from qualitative to quantitative of precision theory is realized.This paper analyzes the accuracy of the most widely used measuring device on the test bench,puts forward improvement measures,formulates the diagnosis scheme of sensor errors and faults,and uses and verifies several anti-interference methods of electrical signals.The rationality of the scheme of measurement,control and diagnosis system is verified by analyzing the results of engine on-load test.