Studies On The Method Of Measuring DTG Linear Vibration Drift Error

Gyroscope is an important components of the inertial navigation system, whose basicfunction is to measure angular displacement and angular rate. Dynamically tunedgyroscope has two degrees of freedom, which has a flexible strut to support gyroscoperotor and isolate driving motor.With the rotor rotating fast,the elastic stiffness ofthe flexible strut canbe compensated by its own dynamic effect.The drift error ofgyroscope caused by linear vibtration is componesed of two parts, one is caused by1Nfrequency of linear vibration with a direction of paralleling to driving shaft, andthe other is caused by2N frequency of linear vibration with a vertical direction withdriving shaft.1N frequency linear vibration drift error results from imblance ofradial,and2N frequency results from non-coplanar of inner flexible shaft and outerflexible shaft and the swing balance ring. The drift error of Gyroscope linear vibrationcombined with gyroscope vibration affect the precision of inertial navigation system.Studies on the method of measuring gyroscope linear vibration drift error ismade. Concrete works are as follows:1.The structure of gyroscope,its working principle and charactertics of twobalance rings are introduced. Mathematical formulas of1N frequency linear vibrationdrif erro and2N frequency linear vibration drift error are deduced with cosideringvibration phase and vibration frequency precision.2.According to mathematical formulas of1N and2N linear vibration drift errors,factors of frequency difference, phase difference, rotor’s centroid displacement andbalance ring’s centroid displacement on1N and2N to frequency linear vibration drif erros are simulated to obtain affecting relationships.3.Designed four methods of measuring linear vibration drift errors: In dynamicconditions,there are same frequency method and difference frequency method accordingto different frequencies of vibration signals.In static conditions, there are openingring method and closing ring method according to weather gyroscope force feedback isblocking, and also calculation formulas of the four measuring methods are given.4.Measuring experiment of linear vibration drift error is made, and testrepeatability and test precision under static and dynamic conditions are obtained.