Dual-filter-based transfer alignment method under dynamic deformation

Patent metadata

Field	Value
Publication number	US-11912433-B2
Application number	US-202017275506-A
Country	US
Kind code	B2
Filing date	Apr 15, 2020
Priority date	May 17, 2019
Publication date	Feb 27, 2024
Grant date	Feb 27, 2024

Abstract

A dual-filter-based transfer alignment method under dynamic deformation. A dynamic deformation angle generated under dynamic deformation and a coupling angle between dynamic deformation and body motion will reduce the accuracy of transfer alignment; and a transfer alignment filter is divided into two parts, the first part estimates a bending deformation angle and the coupling angle, and uses an attitude matching method, and the second part estimates a dynamic lever arm, and uses a “speed plus angular speed” matching method.

First claim

The invention claimed is:

1. A dual-filter-based transfer alignment method under dynamic deformation, applied to an aircraft wing deformation measurement system, in which a main inertial navigation system is installed in a cabin and inertial navigation subsystems are installed on the wings, wherein the method comprises the following steps:
generating attitude, speed and position information of the main inertial navigation system and outputs of a gyro and an accelerometer by using a trajectory generator, simulating flexural deformation angle {right arrow over (θ)} and flexural deformation angular speed {right arrow over (θ)} between the main inertial navigation system and the inertial navigation subsystems by using a second-order Markov, carrying out geometric analysis on the flexural deformation, and deriving an expression of coupling angle Δ{right arrow over (ϕ)} resulted from dynamic deformation of the carrier and movement of the carrier;
using the flexural deformation angle, the flexural deformation angular speed and the coupling angle as state quantities, and establishing a model of filter 1 with an attitude matching method;
establishing a dynamic lever arm model by using the flexural deformation angle and the coupling angle estimated in step (2), and deriving an expression of speed error and an expression of angular speed error;
establishing a model of filter 2 by using the expression of speed error and expression of angular speed error derived in step (3) with a “speed+angular speed” matching method, estimating the initial attitude error of the inertial navigation subsystems, and using this error for initial attitude calibration of the inertial navigation subsystems, so as to accomplish a transfer alignment process.

2. The dual-filter-based transfer alignment method under dynamic deformation according to claim 1 , wherein in step (1), the geometrical analysis on the flexural deformation is carried out and the expression of coupling angle Δ{right arrow over (ϕ)} resulted from the dynamic deformation of the carrier and movement of the carrier is derived as follows:
Δ{right arrow over (ϕ)}= M{right arrow over (ω)} θ ,

wherein, {right arrow over (ω)} θ ={right arrow over ({dot over (θ)})}, and M is expressed as:

M
=

[

0

0

-

1

ω
isy

s
′

-

1

ω
isz

s
′

0

0

0

-

1

ω
isx

s
′

0

]

,

wherein, ω isx s′, ω isy s′ and ω isz s′ represent the ideal angular speeds of the inertial navigation subsystems in east, north, and sky directions respectively.

3. The dual-filter-based transfer alignment method under dynamic deformation according to claim 2 , wherein in step (2), the flexural deformation angle, the flexural deformation angular speed and the coupling angle are used as state quantities and the model of filter 1 is established with an attitude matching method as follows:
the state quantities of the filter 1 are selected as follows:
x 1 =[δ{right arrow over (ϕ)} {right arrow over (ε)} s {right arrow over (ρ)} 0 {right arrow over (θ)} {right arrow over ({dot over (θ)})} Δ{right arrow over (ϕ)}] T ,

wherein, δ{right arrow over (ϕ)} represents attitude error, {right arrow over (ε)} s represents zero drift of gyro measurement in the subsystem, and {right arrow over (ρ)} 0 represents initial installation angle error between the main system and the subsystem;
the state equation of filter 1 is:
{dot over (x)} 1 =F 1 x 1 +G 1 w 1 ,

wherein, F 1 represents the state transition matrix of filter 1, G 1 represents the system noise distribution matrix of filter 1, w 1 represents the system noise of filter 1, the state transition matrix F 1 is expressed as:

F
1

=

[

(

-

ω
→

in
m

×

)

-

C

s
′

n

0

3
×
3

0

3
×
3

0

3
×

Assignees

• Univ Southeast

Inventors

• Chen Xiyuan
• Yang Ping
• Fang Lin
• Wang Junwei

Classifications

• B64D45/00 Primary

  Aircraft indicators or protectors not otherwise provided for · CPC title

• G01C21/16

  by integrating acceleration or speed, i.e. inertial navigation · CPC title

• B64D2045/0085

  Devices for aircraft health monitoring, e.g. monitoring flutter or vibration · CPC title

• B64F5/60 Primary

  Testing or inspecting aircraft components or systems · CPC title

• B64D45/0005 Primary

  Devices specially adapted to indicate the position of a movable element of the aircraft, e.g. landing gear · CPC title