Synchronized docking system

• US 6,254,035 B1
• Filed: 12/10/1998
• Issued: 07/03/2001
• Est. Priority Date: 12/10/1998
• Status: Expired due to Fees

• Current Assignee: National Aeronautics and Space Administration (Government of the United States of America)
• Original Assignee: United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration
• Inventors: Howard, Richard T., Book, Michael L., Bryan, Thomas C.
• Primary Examiner(s): Barefoot, Galen L.
• Application Number:
  US09/228,071
• Time in Patent Office: 936 Days
• Field of Search: 244/159, 244/158.R, 244/161, 244/114.R, 320/2
• US Class Current: 244/172.4
• CPC Class Codes: B64G 1/24 Guiding or controlling apparatus, e.g. for attitude control
• CPC Class Codes: B64G 1/36 using sensors, e.g. sun-sensors, horizon sensors
• CPC Class Codes: B64G 1/646 Docking or rendezvous systems refueling in space B64G1/4024

Abstract

A synchronized target subsystem for use in an automated docking system for docking a chase vehicle with a target vehicle wherein the chase vehicle is provided with a video camera for feeding digitized frames to an image processing unit which feeds signals to a control circuit. The control circuit turns on the video camera to digitize a background frame which will include the target vehicle. After the camera grabs the background frame the control circuit turns on a light, which is carried by carried on the chase vehicle and aimed at the target vehicle, and signals the video camera to digitize a foreground frame. A light sensing circuit on the target vehicle receives the light from the chase vehicle and connects a power supply to lights on the target vehicle such that when the foreground frame is digitized the Lights on the target vehicle will show in the foreground frame. The image processing unit subtracts the background frame from the foreground frame and provides a docking signal.

Claims

1. A synchronized target subsystem for use in automated docking systems wherein a chase vehicle is docked with a target vehicle, said synchronized target subsystem comprising,

a. a plurality of lights mounted on the target vehicle,

b. A power supply carried by the target vehicle,

c. a light sensing circuit mounted on the vehicle for sensing light above a predetermined intensity, said light sensing circuit being adapted to connect the power supply to said lights when said light is sensed,

d. a video camera carried by the chase vehicle for digitizing background and foreground frames,

e. an actuating light mounted on the chase vehicle in a position to direct light at the target vehicle,

f. an image processing unit connected to the camera,

g. a control circuit connected to the image processing unit for receiving a signal from said image processing unit, said control circuit being connected to the video camera and the actuating light for and signaling the video camera to digitize a background frame while the lights on the target vehicle are off, said control circuit then turning on the light on the chase vehicle and signaling the video camera to digitize a foreground frame while the lights on the target vehicle are on, said video camera feeding both frames to the image processing unit for subtraction of the background frame from the foreground frame to provide a docking signal.

2. The system of claim 1 wherein the chase vehicle is provided with means for guiding the chase vehicle to a docked relationship with the target vehicle.

3. The system of claim 2 wherein the guiding means is controlled by signals from the image processing unit.

4. The system of claim 3 wherein the guiding means includes a software processor connected to the image processing unit, a docking process controller connected to the software processor and thruster hardware connected to the docking process controller.

5. The system of claim 4 wherein the light from the actuating light is modulated at a predetermined frequency.

6. A synchronized target subsystem for use in automated docking systems wherein a chase vehicle is docked with a target vehicle, said synchronized target subsystem comprising;

a plurality of light sources carried by the target vehicle for transmitting a plurality of light signals,

a single video camera carried by the chase vehicle for directly receiving said light signals from the target vehicle and for digitizing background and foreground frames based on said light signals,

an image processing unit, carried by the chase vehicle and connected to said video camera, for processing said background and foreground frames,

a power supply carried by the target vehicle for supplying power to the plurality of light sources,

a light sensing circuit carried by the target vehicle for sensing light above a predetermined intensity, said light sensing circuit being adapted to connect the power supply to the plurality of light sources when said light is sensed,

an actuating light source carried by the chase vehicle for directing light at the target vehicle, and

a control circuit connected to the image processing unit for receiving a signal from said image processing unit, said control circuit being connected to the video camera and the actuating light source for signaling the video camera to digitize a background frame while the light sources on the target vehicle are off, said control circuit then turning on the actuating light source on the chase vehicle and signaling the video camera to digitize a foreground frame while the light sources on the target vehicle are on, said video camera feeding both frames to the image processing unit for subtraction of the background frame from the foreground frame to provide a docking signal.