GPS-assisted Sins System Quick-action Base Initial Alignment Method

Abstract

The invention relates to a GPS-assisted initial alignment method of a fast-moving base of a SINS system, belonging to the technical field of combined navigation. Including the use of GPS data and SINS data to calculate the attitude change of the navigation system and the attitude change of the carrier system; constructing the state equation and measurement equation of the SINS / GPS system; using a simplified adaptive unscented Kalman filter algorithm Estimate the value drift; correct the attitude of the SINS system and the output of the gyroscope with the estimated misalignment angle and the constant drift of the gyroscope; realize the initial alignment of the fast-moving base of the SINS system. By estimating the misalignment angle and the gyroscope error in the algorithm, the present invention improves the alignment accuracy and convergence performance, and uses the adaptive algorithm to estimate the measurement noise, thereby avoiding the inconsistency in setting the measurement noise covariance matrix in the previous algorithm. Accurate problem, improves the stability of the alignment algorithm, simplifies the unscented Kalman filter, reduces the calculation amount of the alignment algorithm, and has broad application prospects.

Description

technical field [0001] The invention relates to a GPS-assisted initial alignment method of a fast-moving base of a SINS system, belonging to the technical field of combined navigation. Background technique [0002] Strapdown Inertial Navigation System (SINS) can calculate the attitude, velocity and position of the carrier according to the angular rate output by the gyroscope and the specific force output by the accelerometer, which can provide rich navigation information for many military and civilian equipment. The SINS system needs to know the accurate initial navigation information before navigation. The accuracy of the initial navigation information determines whether the subsequent navigation is reliable. Therefore, accurate initial alignment is the key to accurate navigation of the SINS system. For the high-precision SINS system, the system can determine the initial attitude by sensing the earth's rotation and gravitational acceleration in a static base environment, a...

AI Technical Summary

Problems solved by technology

The nonlinear filtering algorithm under the navigation system does not have the small misalignment angle assumption of the traditional algorithm, the error model is accurate, and the moving base alignment can be completed even if there is a large misalignment angle, but the algorithm has a large amount of calculation and slow convergence speed

Different from the nonlinear alignment algorithm in the navigation system, the initial alignment algorithm in the inertial system converts the attitude calculation problem between the carrier system and the navigation system into the calculation problem of the constant attitude matrix between the two inertial coordinate systems in the inertial system , and use vector observation to estimate it, so the convergence speed is fast, but this method is an open-loop algorithm in principle, and does not have the ability to estimate and compensate inertial device errors, so the error of this algorithm will increase with time , when this method is used in a low-precision inertial navigation system, the alignment accuracy will decrease, and will gradually diverge as the alignment time prolongs

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