Method for Position and Location Detection by Means of Virtual Reference Images

• US 20150253140A1
• Filed: 03/04/2015
• Published: 09/10/2015
• Est. Priority Date: 03/05/2014
• Status: Active Grant

• Current Assignee: Airbus Defence and Space GmbH
• Original Assignee: Airbus DS GMBH
• Inventors: AHRNS, Ingo, HASKAMP, Christoph
• Granted Patent: US 9,857,178 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01C 21/005 with correlation of navigation data from several sources, e.g. map or contour matching G01C21/30 takes precedence
• CPC Class Codes: G01C 21/20 Instruments for performing navigational calculations G01C21/24, G01C21/26 take precedence
• CPC Class Codes: G01C 21/24 specially adapted for cosmonautical navigation
• CPC Class Codes: G01C 21/30 Map- or contour-matching
• CPC Class Codes: G01C 21/38 Electronic maps specially adapted for navigation; Updating thereof
• CPC Class Codes: G01C 21/3826 Terrain data
• CPC Class Codes: G01C 21/3852 Data derived from aerial or satellite images
• CPC Class Codes: G06T 2207/10032 Satellite or aerial image; Remote sensing
• CPC Class Codes: G06T 2207/30252 Vehicle exterior; Vicinity of vehicle
• CPC Class Codes: G06T 7/75 involving models
• CPC Class Codes: G06V 20/13 Satellite images
• CPC Class Codes: H04N 23/00 Cameras or camera modules comprising electronic image sensors; Control thereof

Abstract

A method describes the architecture of a vision-supported navigation system in a terrain using available topographical maps, which is based on already existing methods for detecting prominent terrain features. An offline process used in this case creates a feature database from existing topographical maps, which is subsequently used in an online process for recognising features that have been seen. In this case, virtual reference images of the expected situation are created using computer graphical methods, which are analysed using methods for feature extraction, and a feature catalogue made up of vision-based feature vectors and the associated 3D coordinates of the localised features is derived from the same. These data are stored in a flight system in the form of a model database, for example, and enable navigation close to a reference trajectory and for a planned lighting situation. High localisation characteristics and a correspondingly high navigation accuracy are achieved by means of the possibility of using any desired, not necessarily lighting-invariant, feature extractors.

Claims

1. A method for position and location detection of a camera with respect to a topographical map by means of virtual reference images, characterised in that a feature database (8) is created in an off-line process from existing topographical maps and in that the same is subsequently used in an online process for recognising features that have been seen.

2. The method according to claim 1, characterised in that it is used on-board a flight system.

3. The method according to claim 1, characterised in that a virtual image sequence (6) is calculated, in which for each pixel in the image, a corresponding 3D coordinate in a reference coordinate system is saved.

4. The method according to claim 1, characterised in that virtual reference images of an expected situation are created using computer-graphical methods, which are analysed by means of feature extraction (11), and in that a feature catalogue (8) made up of vision-based feature vectors and the associated 3D coordinates of the localised features is derived therefrom.

5. The method according to claim 4, characterised in that the data are stored in a flight system in the form of a model database (8) and in that navigation then takes place close to a reference trajectory and for a planned lighting situation (3).