CN-122015905-A - Dead zone accurate test method for fiber optic gyroscope

CN122015905ACN 122015905 ACN122015905 ACN 122015905ACN-122015905-A

Abstract

The invention provides an accurate dead zone test method for an optical fiber gyroscope, which comprises the steps of rotating a sensitive axis of the gyroscope in the north and south directions in a direction parallel to a horizontal plane according to a preset speed, judging whether the gyroscope is in the dead zone in the rotating process, and acquiring an included angle between the corresponding sensitive axis and the east direction when the gyroscope rotates just out of the dead zone, so as to obtain the size of the dead zone rotating in the north and south directions, and further obtain the size of the dead zone of the gyroscope. The dead zone accurate test method can clearly know the output data of the gyroscope to be unreal data when the angular rate is small, further compensates the measurement error caused by the dead zone through a compensation algorithm, and can effectively avoid the control instability and other problems of the control system caused by the dead zone problem of the gyroscope.

Inventors

FANG YUAN
WEI YUQIANG
SHI YUNLAI
Ma Hongshuo
YU XIAOZHI
OU HENG
XU LEI
SI QI
WU WEIRAN

Assignees

北京自动化控制设备研究所

Dates

Publication Date: 20260512
Application Date: 20251230

Claims (8)

1. The dead zone accurate test method for the fiber optic gyroscope is characterized by comprising the following steps of: Placing the gyroscope on a vibration isolation horizontal table top in a static mode, setting a sensing axis of the gyroscope to be in a dead zone, collecting a plurality of digital quantities output by the gyroscope according to a preset frequency in a preset time, and obtaining a digital quantity average value output by the gyroscope in the preset time; acquiring an inherent zero offset value of the gyroscope based on the digital quantity average value, the earth rotation angular velocity, the local geographic latitude and the gyroscope scale factor; acquiring a preset included angle based on the inherent zero offset value of the gyroscope, the rotation angular velocity of the earth and the local geographic latitude; Fixing the gyroscope on a position turntable, and setting a preset included angle between a sensitive axis of the gyroscope and the horizontal plane in parallel and the forward east direction, wherein the gyroscope is positioned in a dead zone; the method comprises the steps of rotating a sensitive shaft of a gyroscope to north in a direction parallel to a horizontal plane according to a preset speed, acquiring a first input angular velocity corresponding to a rotation angle in real time in the rotation process, acquiring a first theoretical output value of the gyroscope based on the first input angular velocity, judging whether the gyroscope is in a dead zone or not based on a digital quantity average value and the first theoretical output value of the gyroscope; resetting a sensitive axis of the gyroscope to be parallel to a horizontal plane and form a preset included angle with the forward east direction, wherein the gyroscope is positioned in a dead zone; According to a preset speed, the sensitive axis of the gyroscope rotates in the south direction parallel to the horizontal plane, in the rotating process, a second input angular velocity corresponding to the rotating angle is obtained in real time, a second theoretical output value of the gyroscope is obtained based on the second input angular velocity, and whether the gyroscope is in a dead zone or not is judged based on the average value of digital values and the second theoretical output value of the gyroscope; the dead zone size of the gyroscope is obtained based on the first input angular velocity to obtain the dead zone size of the north rotation and the second input angular velocity to obtain the dead zone size of the south rotation.
2. The method of claim 1, wherein the intrinsic zero offset value of the gyroscope is obtained by: Wherein, omega 0i ＝Ω e .sin phi Wherein, B 0 is the inherent zero offset of the gyroscope, For the numerical average, K is the gyroscope scale factor, Ω 0i is the component of the local earth's rotational angular velocity in the sky direction, Ω e is the earth's rotational angular velocity, and φ is the local geographic latitude.
3. The method of claim 1, wherein the predetermined angle is obtained by: Wherein alpha is a preset included angle.
4. The method of claim 1, wherein the first input angular velocity is obtained by: Ω N ＝Ω e ·cosφ·sinα N the second input angular velocity is obtained by: Ω S ＝Ω e ·cosφ·sinα S Wherein Ω N is a first input angular velocity, α N is a rotation angle of north rotation, Ω S is a second input angular velocity, and α S is a rotation angle of south rotation.
5. The method of claim 1, wherein the first theoretical output value of the gyroscope is obtained by: F 0 ＝(Ω N +B 0 )·K Obtaining a second theoretical output value of the gyroscope by: F 0 ′＝(Ω S +B 0 )·K Where F 0 is the first theoretical output value of the gyroscope and F 0 ' is the second theoretical output value of the gyroscope.
6. The method of claim 1, wherein the gyroscope is in a dead zone when the north-bound rotation is determined when the following equation is satisfied: Judging that the gyroscope is in a dead zone when the gyroscope rotates in the south direction when the following conditions are met:
7. the method of claim 1, wherein the size of the dead zone for the north rotation is obtained by: Ω DN ＝Ω N +B 0 The dead zone size for the southbound rotation is obtained by: Ω DS ＝Ω S +B 0 Where Ω DN is the dead zone size for north rotation and Ω DS is the dead zone size for south rotation.
8. The method of claim 1, wherein the dead zone size of the gyroscope is obtained by: Ω D ＝|Ω DN |+|Ω DS | where Ω D is the dead zone size of the gyroscope.

Description

Dead zone accurate test method for fiber optic gyroscope Technical Field The invention relates to the technical field of dead zone detection, in particular to a dead zone accurate test method of an optical fiber gyroscope. Background The fiber optic gyroscope has the advantages of full solid structure, high sensitivity, quick start, wide dynamic range, small volume, low cost, long continuous working time and the like, and is favored in military and civil navigation and positioning and orientation systems. After decades of development, fiber optic gyroscopes have taken the dominant instrument position in the inertial navigation field. The dead zone effect of the optical fiber gyroscope means that in the range of very small input angular velocity, the output signal of the optical fiber gyroscope is kept to be zero in the section of input angular velocity interval, and the section of input angular velocity interval is the dead zone. A comparison of the output ideal curve of the optical fiber gyroscope for detecting angular velocity and the curve when there is a dead zone is schematically shown in fig. 2. The dashed line in the figure is an ideal dead zone-free output curve, and the solid line is an output curve in the case of dead zones. Along with the development trend of miniaturization and integration of the optical fiber gyroscope, dead zone effect becomes more remarkable or difficult to inhibit, so that accurate test of the dead zone has extremely important significance in the fields of inertial navigation and high-precision sensing. The method is one of key indexes for evaluating the performance of the gyroscope, and directly influences the reliability, precision and dynamic response capability of the system in practical application. Disclosure of Invention The invention provides a dead zone accurate test method of an optical fiber gyroscope, which can solve the technical problems of out-of-control attitude or accumulated error and the like caused by the fact that a system is not sensitive to micro rotation due to inaccurate dead zone test. The invention provides a dead zone accurate test method of an optical fiber gyroscope, which comprises the following steps: Placing the gyroscope on a vibration isolation horizontal table top in a static mode, setting a sensing axis of the gyroscope to be in a dead zone, collecting a plurality of digital quantities output by the gyroscope according to a preset frequency in a preset time, and obtaining a digital quantity average value output by the gyroscope in the preset time; acquiring an inherent zero offset value of the gyroscope based on the digital quantity average value, the earth rotation angular velocity, the local geographic latitude and the gyroscope scale factor; acquiring a preset included angle based on the inherent zero offset value of the gyroscope, the rotation angular velocity of the earth and the local geographic latitude; Fixing the gyroscope on a position turntable, and setting a preset included angle between a sensitive axis of the gyroscope and the horizontal plane in parallel and the forward east direction, wherein the gyroscope is positioned in a dead zone; the method comprises the steps of rotating a sensitive shaft of a gyroscope to north in a direction parallel to a horizontal plane according to a preset speed, acquiring a first input angular velocity corresponding to a rotation angle in real time in the rotation process, acquiring a first theoretical output value of the gyroscope based on the first input angular velocity, judging whether the gyroscope is in a dead zone or not based on a digital quantity average value and the first theoretical output value of the gyroscope; resetting a sensitive axis of the gyroscope to be parallel to a horizontal plane and form a preset included angle with the forward east direction, wherein the gyroscope is positioned in a dead zone; According to a preset speed, the sensitive axis of the gyroscope rotates in the south direction parallel to the horizontal plane, in the rotating process, a second input angular velocity corresponding to the rotating angle is obtained in real time, a second theoretical output value of the gyroscope is obtained based on the second input angular velocity, and whether the gyroscope is in a dead zone or not is judged based on the average value of digital values and the second theoretical output value of the gyroscope; the dead zone size of the gyroscope is obtained based on the first input angular velocity to obtain the dead zone size of the north rotation and the second input angular velocity to obtain the dead zone size of the south rotation. Preferably, the intrinsic zero offset of the gyroscope is obtained by: Wherein, omega 0i＝Ωe.sin phi Wherein, B 0 is the inherent zero offset of the gyroscope,For the numerical average, K is the gyroscope scale factor, Ω 0i is the component of the local earth's rotational angular velocity in the sky direction, Ω e is the earth's rotational a