ADAPTIVE SURVEILLANCE AND GUIDANCE SYSTEM FOR VEHICLE COLLISION AVOIDANCE AND INTERCEPTION

• US 20100292871A1
• Filed: 03/26/2010
• Published: 11/18/2010
• Est. Priority Date: 03/26/2009
• Status: Active Grant

• Current Assignee: University of North Dakota (North Dakota University System)
• Original Assignee: University of North Dakota (North Dakota University System)
• Inventors: Berseth, Brian L., Martel, Florent, Lendway, Matthew, Schultz, Richard R.
• Granted Patent: US 8,380,367 B2
• Time in Patent Office: Days
• US Class Current: 701/3
• CPC Class Codes: G01C 21/3826 Terrain data
• CPC Class Codes: G01C 21/3852 Data derived from aerial or satellite images
• CPC Class Codes: G01S 13/862 Combination of radar systems with sonar systems
• CPC Class Codes: G01S 13/865 Combination of radar systems with lidar systems
• CPC Class Codes: G01S 13/867 Combination of radar systems with cameras
• CPC Class Codes: G01S 13/933 of aircraft or spacecraft
• CPC Class Codes: G05D 1/106 Change initiated in response to external conditions, e.g. avoidance of elevated terrain or of no-fly zones
• CPC Class Codes: G05D 1/1064 specially adapted for avoiding collisions with other aircraft
• CPC Class Codes: G08G 5/0008 with other aircraft
• CPC Class Codes: G08G 5/0078 for monitoring traffic from the aircraft radar or analogous systems specially adapted for traffic control G01S13/91
• CPC Class Codes: G08G 5/0086 for monitoring terrain radar or analogous systems specially adapted for terrain avoidance G01S13/935
• CPC Class Codes: G08G 5/045 Navigation or guidance aids, e.g. determination of anti-collision manoeuvers radar or analogous systems specially adapted for anti-collision between aircraft G01S13/933

Abstract

A surveillance and guidance method and system for use with autonomously guided, man-on-the-loop or man-in-the-loop guided vehicles where the presence of obstacles must be considered in guiding the vehicle towards a target includes a navigation system configured to determine the position of the vehicle on which it is equipped. A communication system is configured for data exchange between the vehicle, neighboring vehicles and ground stations. A surveillance system is configured to detect and locate fixed or moving targets and obstacles. A computer is configured to track the position of targets and obstacles and to provide guidance commands or 4D flight paths to perform collision avoidance with respect to traffic regulations and procedures, and operational airspace restrictions. Additional computer tasks include station keeping or interception of targets. A command and control system is configured to interact with a user interface and control the vehicle'"'"'s actuators.

Claims

1. An aircraft guidance system for use with an aircraft, the system comprising:

a communication subsystem configured for data exchange with cooperative airborne vehicles to acquire cooperative airborne vehicle location data and ground surveillance sources to acquire airborne vehicle location data for other airborne vehicles;

a surveillance sensor subsystem configured to detect azimuth, elevation, and range location data for additional non-cooperative airborne objects, non-airborne obstacles and targets; and

an embedded computer having associated software installed on the aircraft and operably connected to both the surveillance sensor subsystem and the communication subsystem operable to collect location information from the other airborne vehicles and the non-cooperative airborne objects, non-airborne obstacles and targets within a vicinity of the aircraft, predict four-dimensional trajectories of the other airborne vehicles and the non-cooperative airborne objects, non-airborne obstacles and targets within a variable number of miles, assess collision threat potential with respect to the aircraft'"'"'s current flight path, and determine a trajectory to avoid collision with any of the other airborne vehicles and the non-cooperative airborne objects, non-airborne obstacles and targets.

2. The system of claim 1, wherein the surveillance sensor subsystem includes at least one sensor selected from the group comprising:

an Electro-Optical (EO) Camera, a Thermal Infrared (IR) Camera, a Short Wave Infrared (SWIR) Camera, a Phased-Array Radar, a Milli-Meter Wave (MMW) Radar, a Synthetic Aperture Radar (SAR), an Acoustic Sensors/SONAR and LIDAR.

3. The system of claim 1, wherein the communication subsystem comprises at least one sensor selected from the group comprising:

an Automatic Dependent Surveillance—

Broadcast sensor, a Mode S based Traffic Alert—

Collision Avoidance System sensor, and an Automatic Independent Surveillance—

Privacy sensor.

4. The system of claim 1, wherein the embedded computer and associated software are configured to rely on one or more behaviors to generate an objective function from which the desired trajectory of the aircraft is determined.

5. The system of claim 4, wherein the objective function is piecewise linearly defined in a finite decision space.

6. The system of claim 1, wherein the aircraft is an unmanned vehicle.

7. The system of claim 1 and further comprising:

a navigation system that includes a global navigation satellite system receiver, wherein the navigation system is operably connected to the embedded computer.

8. The system of claim 1 and further comprising:

a control system operably connected to the embedded computer, the control system comprising;

a user interface having a display device and an input device;

a flight control system operable in response to commands from the embedded computer and the user interface; and

one or more aircraft actuators controlled by the flight control system.

9. A method for unmanned aircraft operation, the method comprising:

sensing navigation information that includes position, velocity and intended trajectory information for the unmanned aircraft;

sensing surveillance information comprising;

gathering location information of non-cooperative airborne objects; and

gathering location information of additional airborne vehicles and flight obstacles;

harmonizing the navigation information and the surveillance information in a reference frame;

determining if the unmanned aircraft is on-target; and

performing a maneuver if the unmanned aircraft is off-target, wherein performing the maneuver comprises;

determining one or more behaviors that govern guidance of the unmanned aircraft to the target;

generating an objective function, wherein the objective function is generated as a function of the harmonized navigation information and surveillance information in the reference frame and one or more behaviors that governs guidance of the unmanned aircraft to the target; and

controlling the unmanned aircraft in accordance with a trajectory determined by the objective function.

10. The method of claim 9, wherein the step of determining one or more behaviors that govern guidance of the unmanned aircraft to the target involves selection of one or more behaviors from the group consisting of:

reaching a target, avoiding small threats, avoiding large threats, following air traffic regulations and procedures, following a trajectory, loitering over target, maintaining a constant heading, maintaining a constant speed, maintaining a constant altitude, maintaining a constant rate of climb, following a quickest path, following a steadiest path, and following a boldest path.

11. The method of claim 10, wherein one objective function is generated for each of the one or more behaviors.

12. The method of claim 9, wherein the objective function is piecewise linearly defined.

13. A surveillance and guidance system for an aircraft, the system comprising:

a navigation system configured to determine navigation information that includes a position, velocity and intended trajectory of the aircraft;

a communication system configured to communicate location data with at least one of an airborne vehicle, a ground vehicle, a ground station and a radio beacon;

a surveillance sensor configured to sense position data of at least one of a fixed target, a moving target, an obstacle, an airport, a runway and a taxiway within a vicinity of the aircraft;

a flight computer configured to provide one or more guidance commands to guide the aircraft towards a target in the presence of obstacles as a function of the navigation information, the location data and the surveillance position data, wherein the flight computer is configured to track a position of one or more of the fixed target, the moving target, the obstacle, the airport, the runway, the taxiway and navigation aids and is configured to determine a velocity and an intended trajectory of the moving target and obstacles, and wherein the flight computer is configured to generate aircraft status, navigation and surveillance information, alerts and guidance commands for performing at least one of collision avoidance, station keeping and interception of targets; and

a control system configured to process the guidance commands to control the aircraft.

14. The system of claim 13, wherein the navigation system includes an embedded GPS/inertial navigation system.

15. The system of claim 13, wherein the communication system comprises one or more data transceiver systems selected from the group comprising:

an Automatic Dependent Surveillance—

Broadcast transceiver or receiver, a Mode S based Traffic Alert—

Collision Avoidance System, a VHF transceiver, and a wireless data transceiver.

16. The system of claim 13, wherein the surveillance sensor includes a Phased-Array Radar.

17. The system of claim 13, the control system further comprising:

a user interface for interaction with an operator of the aircraft.

18. The system of claim 17, wherein the user interface includes a display device to display any of aircraft status information, the navigation information, the surveillance position data, alerts and the guidance commands.

19. The system of claim 13, wherein the guidance commands include at least one of changing heading, changing speed, and changing altitude of the aircraft.

20. A method for collision avoidance and interception for an aircraft, the method comprising:

determining position, velocity and trajectory information for the aircraft;

receiving positions, velocities and intended trajectories of any cooperative and non-cooperative vehicles;

sensing positions of any neighboring targets, obstacles, airports, runways, taxiways, and navigation aids;

determining velocities and trajectory information of the neighboring targets, obstacles, airports, runways, taxiways, and navigation aids if moving;

receiving inputs from a user interface;

fusing the determined position, velocity and trajectory information for the aircraft, the received positions, velocities and intended trajectories of the cooperative and non-cooperative vehicles, the sensed positions of the neighboring targets, obstacles, airports, runways, taxiways, and navigation aids and the determined velocities and trajectory information of the neighboring targets, obstacles, airports, runways, taxiways, and navigation aids as a fused data set;

displaying the fused data set on the user interface;

comparing the position, velocity and intended trajectory information for the aircraft with the positions of the neighboring targets, obstacles, airports, runways, taxiways and navigation aids, as well as the velocities and intended trajectories of the cooperative and non-cooperative vehicles; and

if the aircraft is on-target, performing an on-target procedure;

or

if the aircraft is not on-target, performing the following steps;

activating one or more behaviors as a function of the fused data set;

generating an objective function as a function of the activated behaviors;

generating a guidance command determined in accordance with the objective function.

21. The method of claim 20, wherein the step of generating a guidance command comprises performing a collision avoidance maneuver according when the position of the aircraft is below a first threshold with respect to threats.

22. The method of claim 21, wherein performing the collision avoidance maneuver comprises at least one of changing heading, speed and altitude of the aircraft.

23. The method of claim 20, wherein the step of generating a guidance command comprises performing a self-separation maneuver when the position of the aircraft is below a second threshold with respect to threats.

24. The method of claim 23, wherein performing the self-separation maneuver comprises at least one of changing heading, speed and altitude of the aircraft.

25. The method of claim 20, wherein the step of generating a guidance command comprises performing a trajectory adjustment procedure when the position of the aircraft is above a third predetermined threshold with respect to the intended trajectory of the aircraft.

26. The method of claim 25, wherein performing the trajectory adjustment procedure comprises at least one of changing heading, speed and altitude of the aircraft.

27. The method of claim 20 and further comprising:

updating a memory device with at least one of information generated automatically or received from the user interface.

28. The method of claim 20, wherein the activation of one or more behaviors as a function of the fused data set comprises one or more behaviors from the group consisting of:

reaching a target, avoiding small threats, avoiding large threats, following air traffic regulations and procedures, following a trajectory, loitering over target, maintaining a constant heading, maintaining a constant speed, maintaining a constant altitude, maintaining a constant rate of climb, following a quickest path, following a steadiest path, and following a boldest path.

29. The method of claim 20, wherein an objective function is generated for each of the one or more behaviors.

30. The method of claim 29, wherein the resulting objective function is computed as a weighted sum of each objective function generated by the behaviors.

31. The method of claim 20, wherein the objective function is piecewise linearly defined in a finite decision space.