The Research Of Fault Diagnosis Technology On Laser Gyro Strapdown Inertial Measurement Unit

Compared with the traditional electromechanical inertial system,laser gyro strapdown inertial measurement unit has the advantages of rapid start-up,stable performance,high precision,long life,stable calibration parameter and low cost.It has been become more and more widely used in aviation,aerospace,and the other related areas.However,it has its own limitation,and the laser inertial units are also prone to the problems such as gyro parameter,accelerometer parameter,engine shaking device,and frequency voltage anomaly in the development,use,testing and maintenance processes.As the core parts of the aircraft control system for rocket and missile,its normal or not will directly affect the success of vehicle testing and launching,so for its fault diagnosis is also becoming more and more important.For this,analysis object was based on laser imu testing workflow,the paper studied the possible kinds of typical failure mode,establishing the fault tree model,temperature time series AR model and the SVM fault diagnosis model of laser gyro pulses,and based on the LabVIEW,then developed the offline-fault-diagnosis expert system.The specific researchworkssuch as the follows:Firstly,this paper summarizes the various typical failure modes that occur during the test and use of the laser inertial units,based on the study of the working principle,composition structure,error model equation and typical test process.Secondly,by Integration of FTA,AR model,the SVM algorithm and other methods.The paper built the fault modeling,identified the parameter anomaly evaluation criteria,and formed 43 fault diagnosis rules,which constitute the knowledge base of expert system.Finally,the general scheme of an off-line auxiliary fault diagnosis expert system was designed.Based on the LabVIEW,five expert system modules such as fault diagnosis of temperature monitoring time sequence model,fault diagnosis of location and rate calibration parameters overproofwere implemented.Tests and verification have been proven,that the expert system works well,and has the ability to locate the fault source of the laser inertial group to the(inertial)device level/(circuit)board level range,and can provide appropriate processing opinions according to the fault model.