CN-115790653-B - Self-alignment method and device for rotary inertial navigation

CN115790653BCN 115790653 BCN115790653 BCN 115790653BCN-115790653-B

Abstract

The invention relates to a self-alignment method and device for rotary inertial navigation, which comprise the steps of obtaining the orientation of a high-precision gyroscope at an initial strapdown position by adopting a quick rough alignment mode, turning the high-precision gyroscope to a set angle in the east-west direction according to the orientation of the high-precision gyroscope, obtaining the initial posture of the initial position by taking the orientation of the high-precision gyroscope as a head position after turning, enabling the high-precision gyroscope to turn to a second position symmetrical to the initial position by taking an zenith axis as a central axis, adopting filtering estimation to carry out fine alignment in the process of turning from the initial position to the second position, obtaining the posture of the turning ending moment at the ending moment of the second position, and carrying out navigation tracking based on the posture of the ending moment of the second position and inertial navigation data in the process of turning around the zenith axis to the initial strapdown position. The product characteristics of the high-low gyroscope collocation can be fully utilized, and the self-alignment precision of the rotary inertial navigation can be effectively ensured.

Inventors

HU HUAFENG
LIU MING
SHI LIJUAN
LU JUNQING
MU JIE
LI DAN
YOU LANG
ZHANG YANGYAN
WANG CHEN

Assignees

湖北航天技术研究院总体设计所

Dates

Publication Date: 20260505
Application Date: 20221122

Claims (9)

1. A self-aligning method for rotational inertial navigation, the method comprising the steps of: acquiring the orientation of a high-precision gyroscope at an initial strapdown position by adopting a rapid coarse alignment mode, and turning the high-precision gyroscope to a set angle in the east-west direction according to the orientation of the high-precision gyroscope; The initial posture of the first position is obtained by taking the direction of the high-precision gyroscope after rotation as the first position, and the high-precision gyroscope is rotated to a second position symmetrical to the first position by taking the vertical shaft as the central shaft; In the process of rotating from the first position to the second position, adopting filtering estimation to perform fine alignment and acquiring the ending moment posture of the rotation ending moment at the second position; Performing navigation tracking to complete self-alignment based on inertial navigation data in the process of rotating to the initial strapdown position around an heaven axis at the ending moment gesture of the second position; The fast rough alignment includes the steps of: acquiring an initial moment of earth inertial coordinate system Pose transformation matrix to N series The X, Y, Z axes of the N system are respectively directed to the east, north and the sky; According to And Acquiring a B-series relative initial moment strapdown inertial navigation inertial coordinate system at the current moment Is a rotation matrix of (a) The said Specific speed of the tether Wherein the B system is an inertial measurement unit body coordinate system, the X axis of the B system faces the sky, the Y axis and the Z axis of the B system are horizontal directions, the B system is an inertial measurement unit body coordinate system Is the projection of the angular velocity of the B system relative to the earth inertia coordinate system I system under the B system, the Outputting a specific force under a body coordinate system B for an accelerometer of an inertial measurement unit IMU, wherein the origin of the I system is positioned at the center of the earth, and the coordinate axis direction is unchanged in an inertial space; Based on the following And said Acquiring the said From the initial moment of the earth inertial coordinate system Is transformed into matrix of the pose of (2) ; According to the described The said And said Calculating an initial attitude transformation matrix of an Inertial Measurement Unit (IMU) 。
2. A self-aligning method for rotary inertial navigation as claimed in claim 1 wherein said fast coarse alignment includes second order inertial frame alignment and least squares fitting based parameter identification.
3. A self-aligning method for rotary inertial navigation as claimed in claim 2 wherein said pose transformation matrix Obtaining based on a first formula, wherein the first formula comprises: , Wherein, the Is the rotational angular velocity of the earth, To align the starting time The latitude of the rotational inertial navigation, To align with the current time.
4.A self-aligning method for rotary inertial navigation as claimed in claim 2 wherein said The said Obtaining based on a second formula, the second formula comprising: , , , Wherein the said Is a matrix of units which is a matrix of units, As a variable of the integral expression, For the current alignment time it is possible to determine, For aligning the start time.
5. A self-aligning method for rotary inertial navigation as claimed in claim 2 wherein said Obtaining based on a third formula, the third formula comprising: , , t 1 =1/2*t 2 , Wherein, the Is the specific force under the N series, Is that Is to be used in the present invention, Is that At t 0 takes 0 and t takes the value of t 1 , Is that At t 0 takes 0 and t takes the value of t 2 , Is that At t 0 takes 0 and t takes the value of t 1 , Is that At t 0 takes 0 and t takes the value of t 2 , Is a variable of the integral expression.
6. A self-aligning method for rotary inertial navigation as claimed in claim 2 wherein said Obtaining based on a fourth formula, the fourth formula comprising: , , , Wherein, among them, Is a direction cosine matrix from B series to N series, A directional cosine matrix from the coordinate system B0 of the initial zero moment to the navigation system L, The axis X, Y, Z in the L system of the navigation system points to north, east and ground respectively.
7. A self-aligning method for rotary inertial navigation according to any one of claims 2 to 6, wherein the step of obtaining the orientation of the initial strapdown position high precision gyroscope by using a fast coarse alignment method comprises the steps of: using an initial pose matrix And storing for a preset time And Navigation solution is carried out to obtain a gesture matrix at each moment Sum speed of ; The velocity is calculated by using a quadratic polynomial Fitting to obtain coefficients of the east and north velocity fits And And based on the coefficient And Calculating an attitude error corresponding to the preset time; Correcting the attitude error and obtaining the orientation of the high-precision gyroscope based on the corrected attitude matrix.
8. A self-aligning method for rotational inertial navigation as claimed in claim 1 wherein said employing filtered estimates for fine alignment comprises the steps of: establishing a state equation according to a first formula, wherein the first formula comprises: , , , Wherein, the Is a state transition matrix and is A matrix of dimensions is provided which, Is system state noise and is Vector of dimension; is an inertial navigation system parameter error state vector, For accelerometer and gyro parameter error state vectors, Is the state vector of the inner lever arm, 、、 Respectively represent components of the carrier position error angle in three directions of X, Y, Z axes under the navigation coordinate system, 、、 The components of the carrier speed error in the X, Y, Z axes under the navigation system are respectively, 、、 The components of the carrier attitude error angle in the X, Y, Z axes under the navigation system are respectively, As a result of the carrier height error, Comprising three accelerometers in turn And zero offset errors corresponding to three gyroscopes , Comprising in turn the projection of the accelerometer on the non-rotational axis on each horizontal axis, 、、 For the navigation system to displace the component of angular velocity in X, Y, Z three directions, 、 For the rotational angular velocity of the earth under the navigation system to be at the Y, Z direction component, Is the radius of curvature of the meridian, For the radius of curvature of the circle of mortise, As the latitude of the person to be latituded, In order to be of a height, the height, 、、 For the velocity component in the three directions of X, Y, Z under the navigation system, 、、 The values of the specific forces measured by the three accelerometers in the navigation system, Representing vectors Is an antisymmetric matrix, subscript of (a) A value representing the previous sampling period, Representing a sampling interval; Establishing a measurement equation according to a second formula, the second formula comprising: , , , Wherein, the For the latitude calculated by inertial navigation, For the longitude of the inertial navigation solution, For the height of the inertial navigation solution, As the latitude of the local site, For the longitude of the local point of use, For the height of the local site, To measure noise; and carrying out Kalman filtering based on the state equation and the measurement equation to correct the inertial navigation system parameter errors and the device parameter errors in real time.
9. A self-aligning device for rotational inertial navigation implementing the method of claim 1, comprising, The coarse alignment module is used for acquiring the orientation of the high-precision gyroscope at the initial strapdown position in a rapid coarse alignment mode and turning the high-precision gyroscope to a set angle in the east-west direction according to the orientation of the high-precision gyroscope; The rotating module is used for acquiring an initial posture of the initial position by taking the direction of the high-precision gyroscope after rotation as the initial position, and enabling the high-precision gyroscope to rotate to a second position symmetrical to the initial position by taking an axial direction shaft as a central shaft; The fine alignment module is used for carrying out fine alignment by adopting filter estimation in the process of rotating from the first position to the second position and acquiring the ending moment posture of the rotation ending moment at the second position; And the navigation tracking module is used for performing navigation tracking to finish self-alignment based on the ending time gesture of the second position and inertial navigation data in the process of rotating to the initial strapdown position around an heaven axis.

Description

Self-alignment method and device for rotary inertial navigation Technical Field The invention relates to the technical field of inertial navigation, in particular to a self-alignment method and device for rotary inertial navigation. Background Currently, in order to improve the navigation accuracy of the inertial navigation system, on one hand, inertial elements with higher accuracy are designed and manufactured, such as new materials, new processes or new inertial devices, and on the other hand, system technologies, such as advanced control strategies and algorithms, are adopted. With the development of the optical gyroscope reaching a higher level, the precision of the inertial device is limited in lifting space. In the system technology, the rotary inertial navigation generally has the functions of self-calibration, self-alignment and self-detection, and is convenient to use and maintain, so that the rotary inertial navigation has wider application. In order to reduce the volume and weight of products, one type of rotary inertial navigation adopts a scheme of matching high precision and low precision when a top is installed, and the space advantage of a top ring lantern ring is fully utilized to realize high-precision small-volume products. The rapidity and the accuracy of the self-alignment are important indexes of rotary inertial navigation, while the currently widely used rotary inertial navigation self-alignment method is mainly focused on theoretical research, laboratory turntable simulation verification or self-alignment by using a rotary modulation flow, and is not combined with the research of a high-accuracy self-alignment method of the characteristics of a high-accuracy gyroscope matched product, particularly the research of engineering application problems such as high-accuracy gyroscope and lever arm error estimation. Disclosure of Invention The embodiment of the invention provides a self-alignment method and a self-alignment device for rotary inertial navigation, which can fully utilize the product characteristics of high and low gyroscopes, and effectively ensure the self-alignment precision of the rotary inertial navigation. In one aspect, an embodiment of the present invention provides a self-alignment method for rotational inertial navigation, which is characterized in that the method includes the steps of: acquiring the orientation of a high-precision gyroscope at an initial strapdown position by adopting a rapid coarse alignment mode, and turning the high-precision gyroscope to a set angle in the east-west direction according to the orientation of the high-precision gyroscope; The initial posture of the first position is obtained by taking the direction of the high-precision gyroscope after rotation as the first position, and the high-precision gyroscope is rotated to a second position symmetrical to the first position by taking the vertical shaft as the central shaft; In the process of rotating from the first position to the second position, adopting filtering estimation to perform fine alignment and acquiring the ending moment posture of the rotation ending moment at the second position; and performing navigation tracking to complete self-alignment based on inertial navigation data in the process of rotating to the initial strapdown position around an heaven axis when the second position is ended. In some embodiments, the fast coarse alignment includes second order inertial frame alignment and least squares fit based parameter identification. In some embodiments, the fast rough alignment comprises the steps of: acquiring an attitude transformation matrix from an initial moment of earth inertial coordinate system E' I0 to an N system The X, Y, Z axes of the N system are respectively directed to the east, north and the sky; According to And f B obtaining a rotation matrix of the B system at the current moment relative to the inertial coordinate system B I0 of the strapdown inertial navigation at the initial momentSpecific speed in the B I0 seriesWherein the B system is an inertial measurement unit body coordinate system, the X axis of the B system faces the sky, the Y axis and the Z axis of the B system are horizontal directions, and the B system is an inertial measurement unit body coordinate systemThe method comprises the steps that (1) the projection of the angular velocity of a B system relative to a geocentric inertial coordinate system (I) is conducted under the B system, f B is the specific force of an accelerometer output body of an Inertial Measurement Unit (IMU) under the B system, the origin of the I system is located at the center of the earth, and the coordinate axis direction is unchanged in an inertial space; Based on the following And saidAcquiring a posture conversion matrix from the B I0 system to an initial moment of the earth inertial coordinate system E' I0 According to the describedThe saidAnd saidCalculating an initial attitude transformation matrix of an Inertia