| Electric control box is a key unit in aircraft electric system, contributing much to the normal operating and flight of aircraft. And the performance of electromagnetic relay affects the electric control box directly and profoundly as being kernel component inside the box. At present, still using manual test console, neither the producer of electric control box, nor the provider of the relay, can offer a highly automatic test solution to improve the efficiency and reliability of test procedure, and most importantly to identify the twinkling-break failure of relay thoroughly.This article is an endeavor to that solution using the high speed compute sampling technology. And basing on data sampling board, a new pattern of synthetic test system has been brought forward, with up to96sampling ports and100kHz sampling rate for each port. It can implement quick and thorough test of switch signals, analog signals output by electric control box with high efficiency, furthermore it can accurately identify the10μs class twinkling-break failure of relay, and thus offers the electric control box producer with good measure in batch production quality assurance. Moreover, researching on twinkling-break inspecting, sampling and storing of gross data, data processing in this article, will certainly benefit the similar test system design in the future with much reference.At first the system design scheme and relative technology have been discussed, and high speed sampling board is selected out of USB(Universal Serial Bus) interface. Secondly, the characteristics and implementation of high speed board in this system have been studied, and sampling adapter circuit and control signal driving circuit, consisted of comparer, high speed optical coupler, CPLD(Complex Programmable Logic Device) and dynatron, have been designed after analyze. Later, SCM(Single Chip Micyoco) serial sampling method has also been considered combing software and SCM together, to enhance the applicability during temperature cycling test of electric control box. And finally,1-drive-5option, which means1console can test5boxes automatically and simultaneity, has been achieved only by software configuration in different complex test procedures. Principle scheme and PCB drawing have both been finished for all function unit during the system hardware design.To meet the requirements of test system, software design focus on three keystones besides display and human-machine interface, these are:1. Coordinating between several high speed sampling boards and WINDOWS operating system based on the analyze of board performance, for which coordinating mechanism has been designed and code implemented,2. Double buffer method of data storing on hard disk engaging gross data, to avoid data losing under overflow on non-high speed disk, and spare enough time for display and human operating,3. Data processing based on synchronizing feedback signal provided by hardware, to identify possible twinkling-break failure and generate report. Flow chart and key code has been provided in this article.In the end, system has been debugged combining hardware and software together, and problem has been fixed. The debug report and analyze has proven that the system presented by this article... |
