Design And Optimization Of The Cable Auto-test System For An Aircraft

The cables assembled on the aircraft are the nervous system of aircrafts. Since the reliability of cables is related to the safety of the aircraft, it’s necessary to test the performance of continuity, insulation of cables and finish all the troubleshooting before the aircraft is energized. Because functions of modern aircrafts are becoming more and more powerful, the cable-net is becoming more and more complicated, which greatly increases the difficulty of aircraft’s cable test.This paper takes testing nearly 30000 end-points in the aircraft as an example. The paper adopts different test ways based on their different distributing features and then gets the cable auto-test system, as well as the voltage test system. Furthermore, it focuses on the optimization of the grouping of end-points and positions of test equipments. The main contents include the following aspects:1 The introduction, this paper elaborates the application and research status about the cable test technologies at home and abroad.2 Taking an aircraft as an instance, this paper in detail analyses the design technology requirements, theories and methods of the two-wire measurement method, four-wire measurement method, insulation performance and shielding effect. Then a cable auto-test system is designed, which consists of adapter cables, Active LRUs (Line Replace Unit), terminal modules, control bus, distributed test cabinets and probes.3 The G-NCR algorithm is proposed to optimize the grouping of end-points to be tested and positions of distributed test cabinets, improving the economic worth of the cable auto-test system. Firstly, the mathematical model of the system cost is built based on that of distributed test cabinets and adapter cables. Secondly, this paper concentrates on the analysis of theories of Genetic Algorithm and the Nearest Center Reclassification Algorithm, as well as the principles to determine parameters and the flow of programming. Finally, an example is used to verify the effectiveness of the G-NCR algorithm.4 Apply the cable auto-test system to an aircraft, make the G-NCR algorithm as the optimization method and write the source program by Matlab. Then search the optimal combinational results between the grouping of end-points to be tested and the positions of distributed test cabinets, and obtain the optimal total cost of the system. By comparison, we get that the total cost of the system is saved by 11.9% and the adapter cables is shortened by 37.2%.5 Summarize the primary research work and prospect the further studies.