Research Of Engine Test-Bed Testing System Based On LabVIEW

Engine testing is a necessary step in engine-producing and engine research. With the development of science and technology, the disadvantages of traditional testing instruments have come out. The development of computers and electronic technology promoted the progress of virtual instruments. Now, testing instruments tend to be flexible. Customers can build their own testing system according to their practical requirement. The testing system can be extended, amended and upgraded without changing the hardware or only changing a little. The whole system is flexible, low cost and high efficient.In this article, a set of performance testing system of engine test-bed was designed by LabVIEW of NI Company which was used as development platform. First, the constitution and features of virtual instrument and LabVIEW graphical programming language and the function of LabVIEW were studied. Besides, the basic measurement principle and methods of engine performance testing parameters were also analyzed. On this basis, the overall system design was conducted, the system design requirements and principles were proposed, the design thought of the system and the basic software structure and hardware components were built.According to the demands of engine testing system, the system hardware were designed and configured. In the system, PC-DAQ form of virtual instrumentation and serial communication were adopted. Sensor, data acquisition cards were selected, signal conditioning circuit were designed and the existing dynamometers, fuel consumption were utilized.The overall framework of the system software were completed based on modular design, the system functions were divided into modules, such as data acquisition, data processing, data save, data read, alarm. In the process of program design, it made full use of the characteristic of hierarchy and modularization of LabVIEW. First of all each modular was programmed and debugged. Then all functional modules were contacted and combined, the related Control and Indicator on Front panel were added and collated to complete system software. The role of system software is to achieve the required functions of system, such as acquisition, monitoring with alarm, displaying, recording, reading of some engine performance parameters, as well as the drawing of characteristic curve of basic engine performance. It should also have a good user interface and easy operation.Compared with the traditional test equipment, virtual instruments contain all the test content in its function module. Based on the process of calling the device driver program, it controls gather transmission by combining various function modules and generating software which is easily expanded and changed. Besides, it can also operate the whole system to display, store, read and process the test data by making full use of powerful graphical user interface.