Multi-sensor merging based super-close distance autonomous navigation apparatus and method

Patent metadata

Field	Value
Publication number	US-9557177-B2
Application number	US-201515105459-A
Country	US
Kind code	B2
Filing date	Feb 10, 2015
Priority date	Dec 30, 2014
Publication date	Jan 31, 2017
Grant date	Jan 31, 2017

Abstract

The present invention discloses a multi-sensor merging based super-close distance autonomous navigation apparatus and method. The apparatus includes a sensor subsystem, an information merging subsystem, a sensor scanning structure, and an orientation guiding structure, wherein a visible light imaging sensor and an infrared imaging sensor are combined together, and data are acquired by combining a passive measurement mode composed of an optical imaging sensor and an active measurement mode composed of a laser distance measuring sensor. Autonomous navigation is divided into three stages, that is, a remote distance stage, implemented by adopting a navigation mode where a binocular visible light imaging sensor and a binocular infrared imaging sensor are combined, a close distance stage, implemented by adopting a navigation mode where a binocular visible light imaging sensor, a binocular infrared imaging sensor and a laser distance measuring sensor array are combined, and an ultra-close distance stage, implemented by adopting a navigation mode of a laser distance measuring sensor array. Through the present invention, the field of view and the exploration range are widened, the problem of shielding existing in passive measurement is effectively solved, the precision of data measurement is ensured, and the navigation efficiency and the safety and reliability of navigation are improved.

First claim

The invention claimed is:

1. An autonomous navigation apparatus, comprising a sensor subsystem, an information merging subsystem, a sensor scanning structure, and an orientation guiding structure; wherein,
the sensor subsystem is installed on the orientation guiding structure, and comprises first and second infrared imaging sensors, first and second visible light imaging sensors, and first to fifth laser distance measuring sensors;
the information merging subsystem comprises an infrared information processing board, a visible light information processing board, and a satellite house-keeping server; the first and second infrared imaging sensors are respectively connected to the infrared information processing board via a bus, the first and second visible light imaging sensors are respectively connected to the visible light information processing board via the bus, the first to fifth laser distance measuring sensors are respectively connected to the satellite house-keeping server, the infrared information processing board and the visible light information processing board are respectively connected to the satellite house-keeping server via the bus; and the satellite house-keeping server is configured to send a control instruction for instructing the sensor subsystem to perform attitude adjustment in combination with a binocular infrared image collected by the first and second infrared imaging sensors, a binocular visible light image collected by the first and second visible light imaging sensors, and laser data collected by the first to fifth laser distance measuring sensors;
the sensor scanning structure includes first and second rotary platforms connected to the satellite house-keeping server, the first and second visible light imaging sensors are respectively installed on the first and second rotary platforms, and the satellite house-keeping server controls the first and second rotary platforms to rotate, such that the first and second visible light imaging sensors can implement spatial object scanning within a range of a field of view;
the orientation guiding structure includes a 2-DOF pan-tilt and a pan-tilt servo controller; and the pan-tilt servo controller is connected to the satellite house-keeping server, for receiving a control instruction from the satellite house-keeping server, to control the 2-DOF pan-tilt to perform attitude adjustment, so as to enable the sensor subsystem to perform attitude adjustment.

2. The autonomous navigation apparatus of claim 1 , wherein, the first visible light imaging sensor, the first infrared imaging sensor, the first laser distance measuring sensor, the second infrared imaging sensor, and the second visible light imaging sensor are arranged in sequence on the same guide rail, the first visible light imaging sensor and the first infrared imaging sensor are symmetrical to the second infrared imaging sensor and the second visible light imaging sensor with respect to the first laser distance measuring sensor; the second to fifth laser distance measuring sensors have the same distance from the first laser distance measuring sensor, the second and third laser distance measuring sensors are symmetrical with respect to the guide rail, and the fourth and fifth laser distance measuring sensors are symmetrical with respect to the guide rail.

3. An autonomous navigation method using the apparatus of claim 1 , comprising the following steps:
(1) collecting a binocular infrared image by using first and second infrared imaging sensors, collecting a binocular visible light image by using first and second visible light imaging sensors, and detecting and positioning a spatial object by using the binocular infrared image and the binocular visible light image, to obtain a relative distance between the navigation apparatus and the spatial object;
(2) judging whether the relative distance between the navigation apparatus and the spatial object is greater than 100 m, if yes, pushing the navigation apparatus towards the spatial object, and returning to step (1); and otherwise, sequentially performing step (3);
(3) collecting a binocular infrared image by using the first and second infrared imaging sensors, collecting a binocular visible light image by using the first and second visible light imaging sensors, collecting laser data by using first to fifth laser distance measuring sensors, and using the binocular infrared image, the binocular visible light image, and the laser data to obtain three-dimensional structure information, three-dimensional distance information, and a three-dimensional motion parameter of the spatial object;
(4) judging whether the relative distance between the navigation apparatus and the spatial object is greater than 20 m according to the three-dimensional distance information of the spatial object, if yes, pushing the navigation apparatus towards the spatial object, and returning to step (3); and otherwise, sequentially performing step (5);
(5) collecting laser data by using the first to fifth laser distance measuring sensors, and using the laser data, in combination with the three-dimensional structure information and the three-dimensional motion parameter of the spatial object obtained in step (3), to obtain the relative distance and a relative attitude angle between the navigation apparatus and the spatial object;
(6) judging whether the relative attitude angle between the navigation apparatus and the spatial object is 0, if yes, sequentially performing step (7); and otherwise, adjusting the attitude of the navigation apparatus, reducing the relative attitude angle between the navigation apparatus and the spatial object, and returning to step (5);
(7) pushing the navigation apparatus towards the spatial object; and
(8) repeatedly performing steps (5) to (7), until the navigation apparatus arrives at the spatial object, to complete a relative navigation process.

4. The autonomous navigation method of claim 3 , wherein the step (1) further includes the following sub-steps:
(1-1) collecting the binocular infrared image by using the first and second infrared imaging sensors, collecting the binocular visible light image by using the first and second visible light imaging sensors, respectively processing the binocular infrared image and the binocular visible light image, and separating the spatial object from a background, to obtain a region of interest of the spatial object;
(1-2) extracting a spatial object profile, tracking the spatial object profile, calculating a two-dimensional graphics center of the spatial object profile, to obtain that the coordinates of the center of the spatial object profile in a left visible light image and a right visible light image of the binocular visible light image are respectively (U 1 ,V 1 ) and (U′ 1 ,V′ 1 ), thereby further obtaining a center coordinate

(

U
1
′

+

U
1

2

,

V
1
′

+

V
1

2

)

of the spatial object in the binocular visible light image; and to obtain that the coordinates of the center of the spatial object profile in a left infrared imag

Assignees

• Univ Huazhong Science Tech

Inventors

• Zhang Tianxu
• Fan Sufei
• Chen Yimeng
• Yao Heng
• Li Zhengtao
• Wang Zheng
• Huang Wei
• Huang Zhenghua

Classifications

• B64G1/244

  Spacecraft control systems · CPC title

• G01C3/14

  with binocular observation at a single point, e.g. stereoscopic type (G01C3/20 takes precedence) · CPC title

• B64G1/36

  using sensors, e.g. sun-sensors, horizon sensors · CPC title

• G06T7/70

  Determining position or orientation of objects or cameras (camera calibration G06T7/80) · CPC title

• G06T2207/30261

  Obstacle · CPC title