Ground collision avoidance system (iGCAS)

• US 9,633,567 B1
• Filed: 12/04/2014
• Issued: 04/25/2017
• Est. Priority Date: 12/04/2014
• Status: Active Grant

• Current Assignee: United States of America as represented by the Administrator of NASA
• Original Assignee: United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration
• Inventors: Skoog, Mark A, Prosser, Kevin, Hook, Loyd
• Primary Examiner(s): Black, Thomas G
• Assistant Examiner(s): Louie, Wae
• Application Number:
  US14/560,068
• Time in Patent Office: 873 Days
• Field of Search: 701301, 701 9, 340961, 340970, 340974, 342 29, 342455
• CPC Class Codes: B64D 45/04 Landing aids; Safety measures to prevent collision with earth's surface
• CPC Class Codes: G01S 13/935 for terrain-avoidance
• CPC Class Codes: G06F 30/20 Design optimisation, verification or simulation optimisation, verification or simulation of circuit designs G06F30/30
• CPC Class Codes: G08G 5/0021 located in the aircraft
• CPC Class Codes: G08G 5/0039 Modification of a flight plan
• CPC Class Codes: G08G 5/0086 for monitoring terrain radar or analogous systems specially adapted for terrain avoidance G01S13/935
• CPC Class Codes: G08G 5/04 Anti-collision systems
• CPC Class Codes: G08G 5/045 Navigation or guidance aids, e.g. determination of anti-collision manoeuvers radar or analogous systems specially adapted for anti-collision between aircraft G01S13/933
• CPC Class Codes: G08G 5/06 for control when on the ground

Abstract

The present invention is a system and method for aircraft ground collision avoidance (iGCAS) comprising a modular array of software, including a sense own state module configured to gather data to compute trajectory, a sense terrain module including a digital terrain map (DTM) and map manger routine to store and retrieve terrain elevations, a predict collision threat module configured to generate an elevation profile corresponding to the terrain under the trajectory computed by said sense own state module, a predict avoidance trajectory module configured to simulate avoidance maneuvers ahead of the aircraft, a determine need to avoid module configured to determine which avoidance maneuver should be used, when it should be initiated, and when it should be terminated, a notify Module configured to display each maneuver'"'"'s viability to the pilot by a colored GUI, a pilot controls module configured to turn the system on and off, and an avoid module configured to define how an aircraft will perform avoidance maneuvers through 3-dimensional space.

Claims

1. A computerized ground collision avoidance system (iGCAS) comprising a computer processor including a transitory computer-readable storage device and a non-transitory computer-readable storage device storing a plurality of software modules including:

a sense own state module configured to gather data to compute trajectory;

a sense terrain module including a digital terrain map (DTM) and map manger routine to store and retrieve terrain elevations;

a predict avoidance trajectory module configured to simulate avoidance maneuvers ahead of a flight path by computing one or more avoidance trajectories;

a predict collision threat module configured to generate one or more elevation profiles, each one of said one or more elevation profiles corresponding to terrain under each of said one or more avoidance trajectories computed by said predict avoidance trajectory module;

a determine need to avoid module configured to determine which of said one or more avoidance trajectories should be used, when it should be initiated, and when it should be terminated by comparing said one or more avoidance trajectories and said corresponding one of said one or more elevation profiles from said predict avoidance trajectory and predict collision threat modules;

a notify module configured to display the viability of each one of said one or more avoidance trajectories to the pilot and, when needed, to direct the pilot through the avoidance trajectory by a colored GUI;

a pilot controls module configured to turn the system on and off as well as configure the system personal protection and warning needs;

an avoid module configured to define how an aircraft will perform avoidance trajectories through 3-dimensional space.

2. The computerized ground collision avoidance system of claim 1, wherein said collision avoidance system further comprises a common interface configured to enable said sense own state module, said sense terrain module, said predict avoidance trajectory module, said predict collision threat module, said determine need to avoid module, said notify module, said pilot control module and said avoid module to exchange data with other ones of said modules and with an existing flight controller.

3. The computerized ground collision avoidance system of claim 2, wherein said sense own state module is configured to regularly interrogate said flight controller using said common interface and to collect flight parameters from said flight controller.

4. The computerized ground collision avoidance system of claim 2, wherein said sense own state module is configured to calculate flight parameters based on data received from said flight controller.

5. The computerized ground collision avoidance system of claim 1, wherein said sense terrain module is configured to utilize standard rasterized data.

6. The computerized ground collision avoidance system of claim 1, wherein said sense terrain module is configured to utilize special formatted terrain data.

7. The computerized ground collision avoidance system of claim 1, wherein said sense terrain module is configured to interrogate said sense own state module via said common interface, and wherein said sense terrain module is further configured to utilize said digital terrain map to generate a real-time local map having an array of cells, and to add and discard one or more of said cells in said array of cells to reflect the real-time position of a vehicle.

8. The computerized ground collision avoidance system of claim 7, wherein said sense terrain module is configured to generate a plurality of real-time local maps, wherein each of said plurality of real-time local maps has a different resolution.

9. The computerized ground collision avoidance system of claim 1, wherein for each of said avoidance trajectories, said predict avoidance trajectory module is configured to utilize a kinematic model to predict a roll-axis time-history response, a speed time-history response, and a pitch axis time-history response of said vehicle, wherein each of said roll-axis, speed and pitch axis time-history responses further comprise a lag/delay phase, an onset phase, and a steady state phase.

10. The computerized ground collision avoidance system of claim 1, wherein said delay phase accounts for one or more of a computational delay, a communications delay, a vehicle dynamic response delay, and a pilot reaction time delay.

11. The computerized ground collision avoidance system of claim 10, wherein said predict avoidance trajectory module is further configured to calculate a range and ground track of said vehicle for each of said avoidance trajectories.

12. The computerized ground collision avoidance system of claim 1, wherein said predict collision threat module is configured to receive said one or more avoidance trajectories calculated by said predict avoidance trajectory module, and wherein said predict collision threat module is further configured to use a digital terrain inter-post interpolation model to calculate a terrain elevation histogram corresponding to each of said one or more avoidance trajectories.

13. The computerized ground collision avoidance system of claim 12, wherein each of said terrain elevation histograms accounts for estimate position uncertainty and wingspan of said vehicle.

14. The computerized ground collision avoidance system of claim 1, wherein said determine need to avoid module is configured to determine when all of said one or more avoidance trajectories becomes invalid, and to thereafter transmit warning signals via said common interface to said flight controller.

15. The computerized ground collision avoidance system of claim 1, wherein said determine need to avoid module is configured to determine when all of said one or more avoidance trajectories becomes invalid, and to thereafter transmit warning signals via said common interface to said notify module.

16. The computerized ground collision avoidance system of claim 1, wherein said notify module comprises a viable maneuver display screen and an avoidance director display screen.

17. The computerized ground collision avoidance system of claim 1, wherein said avoidance system is configured to operate on a smartphone device.

18. A method of avoiding aircraft ground collision, comprising the steps of:

gathering data to compute flight trajectory;

storing and retrieving terrain elevations from a digital terrain map (DTM) using a map manager routine;

simulating avoidance maneuvers ahead of an aircraft by computing one or more avoidance trajectories;

generating one or more elevation profiles corresponding to terrain under each of said one or more avoidance trajectories;

comparing said one or more avoidance trajectories with said corresponding one of said one or more elevation profiles to determine which of said one or more avoidance trajectories should be used, when it should be initiated, and when it should be terminated;

displaying the viability of each one of said one or more avoidance trajectories to a pilot of said aircraft; and

determining how well said aircraft will perform each one of said one or more avoidance maneuvers in three-dimensional space.