The Design Of The External System Equivalent Device For A Measuring System

Aircraft is the core of military system,which made a great contribution in flight andexploration.The external system equivalent device as the important approach of aircraftperformance detection,which obtained real-time flying information of aircraft,plays a crucialrole for the design and operation of aircraft.The paper was based on a project called the external system equivalent device ofaircraft.After understanding the research status of the aircraft testing system at home andabroad, combined with the experience of the scientific research team,the overall designscheme of the system was proposed according to the specific requirement.The system usedstandardized and modular design principle,then the external system equivalent device wasdivided into several functional cards to realize the whole function.We also designed theprotocols for the external system equivalent device, and standardized protocols were madeamong the various of functional cards.The whole control and display of the system was completed by the host computer whichworked as the terminal device.PCI bus interface card was adopted to conduct thecommunication between equivalent device and host computer.Finally,the system realized7-channel422serial digital signals which has specific frame structure,10-channel data ofspecific frame structure485serial digital signals,184-channel charged and not charged switchinstructions,31-channel analog pulse signals which can be set up for number and frequency ofpulses,4-channel specific frequency and amplitude sine wave signals,and1553B buscommunication signals. Through experimental verification,the signals put outed by thisdevice could satisfy the needs of task document,and the equivalent device could meet therequirements of the project in terms of reliability and integrity of performance.The external system equivalent device for a measuring system designated in this paperhad the advantage of simple structure, high precision,it also has powerful versatility andinterchangeability,and has broad application prospects in the test and control of aircraft. Atthe same time,the paper conducts detailed state and discussion to the design of hardware circuit and software,and summarized the whole design process.