Design And Implementation Of Portable Harness Component Test System Based On LabVIEW

Wire harness and component testing system is used for measuring certain type missile series harness and component,which is the important part in the R&D,production and maintenance.Because there are a lot of wire harness and components within the missile,coupled with poor storage environment.In order to eliminate faults,meanwhile,to ensure the reliability of the missile itself,it needs to periodically measure the performance parameters and has the ability to save test data.The present instrument for measuring wire harness and component in the missile is relatively single and simple,it can't achieve the capabilities of portable,fast and generality.In the face of the current treacherous battlefield environment,it is becoming more and more important to design a wire harness and component testing system with portable,high stability and convenient operation.Firstly,the research and application results of wire harness and component test system at home and abroad are briefly introduced.In view of the shortage of the existing equipment technology and the technical requirements of the project,this thesis presents an overall design scheme of the portable wiring harness component testing system based on LabVIEW.The system uses LabVIEW integrated software as the host computer software to develop test system,and adopts ARM Processor embedded system as the slave computer.Host computer can realize the real-time control of the slave computer,and real-time transmission of data,collected data can be stored,query and print,also has a large database of remote timing interface.The lower computer system is composed of 1 master measurement system board and 12 relay interface boards,which can realize the measurement of the electrical parameters of the 384 largest measuring points simultaneously.The master machine measurement system board completed the selection and control of the 12 relay interface boards.At the same time,signal is amplified,filtered and A/D collected in the gated channel.Finally,the collected data is transmitted through the USB interface to the host computer.This thesis describes the overall scheme design,measurement principle,hardware system design and software design of the upper and lower computer of the portable wire harness component test system.The thesis focuses on how to reduce the influence of the leakage current of the relay matrix on the large resistance measurement error and improve the accuracy of the small resistance measurement under the excitation of the AC source.For the largeresistance measurement,the error calculation is carried out in this thesis,and the design accuracy is ensured by the number of simultaneous access loops of the subordinate machine program control relay.Aiming at the DC error of the circuit and the noise interference of the electronic device,the mechanism of the error source is analyzed,and the direct current error is eliminated by using the current backward test method in the hardware design.At the same time,the non-linear detection method of Duffing oscillator detection is used to detect the signal,Through the improvement of constant current source hardware circuit design and host computer program,to achieve a weak signal containing noise detection and processing functions.The test results show that the proposed resistance measurement scheme can effectively improve the test accuracy of the multi-point harness assembly test system,the measurement accuracy of the test system to meet the technical requirements of the project.