GPS-assisted SINS system quick moving base initial alignment method

Abstract

The invention relates to a GPS-assisted SINS system quick moving base initial alignment method, and belongs to the technical field of integrated navigation. The method comprises the following steps: using GPS data and SINS data to calculate navigation system posture change and carrier system posture change; constructing a state equation and a measuring equation of an SINS / GPS system; using a simplified adaptive unscented Kalman filtering algorithm to estimate a misalignment angle and gyroscope constant drift; using the estimated misalignment angle and gyroscope constant drift to correct the output of SINS system aligned posture and a gyroscope; and realizing quick moving base initial alignment of an SINS system. By estimating the errors of the misalignment angle and the gyroscope in the algorithm, the precision and convergence performance of alignment are improved, the measuring noise is estimated by using an adaptive algorithm, the problem that the arrangement of a noise measuring covariance matrix in an original algorithm is inaccurate is avoided, the stability of an alignment algorithm is improved, the unscented Kalman filtering algorithm is simplified, the calculated quantity of the alignment algorithm is reduced, and the application prospect is wide.

Description

technical field [0001] The invention relates to a method for initial alignment of a fast moving base of a GPS-assisted SINS system, belonging to the technical field of integrated navigation. Background technique [0002] The 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, and can provide rich navigation information for many military and civilian equipment. The SINS system needs to know the accurate initial navigation information before navigation, and the accuracy of the initial navigation information determines whether the subsequent navigation is reliable. Therefore, precise initial alignment is the key to accurate navigation of the SINS system. For a high-precision SINS system, the system can determine the initial attitude by sensing the earth's rotation and gravitational acceleration in a static base envir...

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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