Optical-fiber strap-down inertial measurement unit reciprocating-type two-position north finding method for inhibiting slope error influence of devices

Abstract

The invention discloses an optical-fiber strap-down inertial measurement unit reciprocating-type two-position north finding method for inhibiting slope error influence of devices, which is characterized in that: a reciprocating-type two-position alignment process is adequately utilized, on the basis of a traditional best two-position alignment and under the situation that hardware cost is not increased, constant errors of the devices can be effectively eliminated through reasonable design of rotation time intervals, rotation ways, the design parameters of a filter, and the like, influence of slope errors of the devices can also be inhibited, and the north finding precision of an optical-fiber inertial measurement unit can be improved.

Description

technical field [0001] The invention relates to an optical fiber strapdown inertial group reciprocating two-position north-finding method for suppressing the influence of device slope errors, and belongs to the inertial technical field. Background technique [0002] 1. Optical fiber strapdown inertial navigation [0003] Strapdown inertial navigation is a completely autonomous navigation method, which has the advantages of not relying on external information, strong concealment, flexible maneuvering, etc., and has multi-functional parameter output; compared with platform inertial navigation, strapdown inertial navigation system does not need The precise and stable platform reduces the hardware structure, so the cost is greatly reduced. Fiber optic strapdown inertial navigation generally consists of three fiber optic gyroscopes and three accelerometers. Among them, compared with traditional mechanical gyroscopes, fiber optic gyroscopes have outstanding advantages such as no...

AI Technical Summary

Problems solved by technology

[0011] In the existing technology, the Kalman filter method is usually used to estimate the constant value error of the inertial device online and compensate it. For the static base alignment scheme at a fixed position, the drift and observability of the gyro constant value are poor, so The estimation accuracy is not high, and the zero bias of the accelerometer cannot be estimated, resulting in unsatisfactory compensation effect

For the disadvantages of poor observability during initial alignment of static base strapdown inertial navigation system:

[0018] However, Document 4 and Patent 4 only proposed a compensation scheme for the constant value drift of the gyroscope, and did not propose a compensation scheme for the constant value drift of the accelerometer; at the same time, no compensation scheme for the slope drift error of the inertial device was proposed.

Moreover, the purpose of gyro drift compensation is achieved by adding a monitoring gyro and indexing mechanism, which increases the cost of the system, and the indexing mechanism can introduce errors

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