Design Of Data Acquisition System For Comprehensive Diagnosis Of Avionics System

At present,the parameters used in the fault diagnosis method of avionics system is single,which leads to the low rate of fault detection and isolation.In order to improve the fault detection,isolation rate of the system and system test technical indicators,reduce or eliminate the system false alarm,can obtain parameters from system,and use the various useful parameters of the system,apply the comprehensive diagnosis method deal with the parameters to achieve the above purpose.Therefore,the purpose of this paper is to design the data acquisition system to get the parameters of avionics system.In this paper,complete the fault diagnosis data acquisition system design based on the ARM embedded in the ?C/OS-? environment.In this paper,the hardware implementation of the embedded system followed the low power requirements,in the device selection as far as possible to select low-power devices,while the various hardware modules for low-power processing,in a non-working state at the sleep state,use the microprocessors to dynamic manage the system operating frequency,reduce power consumption.In this paper,the feasibility of the system design is analyzed by combining the chip manual and related references,and the overall scheme of the system is given.In the device selection,the system uses low-power 32-bit ARM microprocessor as the system master chip,and implant ?C/OS-? operating system to enhance the system's controllability and operability;data acquisition module The system uses the LTC1857 as the system AD acquisition chip,the analog signal to achieve multi-channel acquisition function;The system uses TJA1050 data transceiver chip,use CAN bus to achieve the machine and PC data communication.In the software implementation,the system consists of two parts,the machine control program and the computer on-line fault diagnosis software composed.The main work includes the transplantation of ?C/OS-? system and the system for data acquisition,storage,transmission,power conditioning and other operations,this paper gives the design ideas and implementation Process.The on-line fault diagnosis software was be designed in the VS2010 development environment,the main function of the on-line fault diagnosis software is convert the data that transmition over from the CAN bus,display the collected data values,through the fault diagnosis algorithm,the data analysis to determine the health of the target circuit,at the while,the data was be storage into the database,this paper gives the online fault diagnosis software design ideas and implementation process.After finish the design of the PCB,printed-circuit board,hardware platform is built and the software is completed,need to test and debug the system.Through the analysis of the data to prove that the design to meet user requirements,the acquisition error of the voltage,current,power are all within ±1%,and lower the ±5%.circute,and also achieve the function of the temperature and acceleration speed acquisition.The system has the characteristics of small size,low power consumption,high acquisition channel and signal quantity in hardware design.At the same time,it has both the data monitoring function and the on-line fault diagnosis function of the collected module,and conduct health assessment.This design provides a reference for the future application of fault diagnosis theory.