Vehicle Guidance System

• US 20080027594A1
• Filed: 07/31/2006
• Published: 01/31/2008
• Est. Priority Date: 07/31/2006
• Status: Active Grant

• Current Assignee: University of Liverpool
• Original Assignee: University of Edinburgh, University of Liverpool
• Inventors: Lee, David N., Jump, Michael, Padfield, Gareth D.
• Granted Patent: US 8,065,044 B2
• Time in Patent Office: Days
• US Class Current: 701/11
• CPC Class Codes: G05D 1/106 Change initiated in response to external conditions, e.g. avoidance of elevated terrain or of no-fly zones

Abstract

A vehicle guidance system comprising: a measurement system; a processor arranged to receive information from the measurement system and convert said information into at least one time-to-contact based parameter; and a control system arranged to receive the at least one time-to-contact based parameter from the processor and use the at least one time-to-contact based parameter to either automatically guide the vehicle or to provide vehicle guidance information to a pilot.

Claims

1. A vehicle guidance system comprising:

a measurement system;

a processor arranged to receive information from the measurement system and convert said information into at least one time-to-contact based parameter; and

a control system arranged to receive the at least one time-to-contact based parameter from the processor and use the at least one time-to-contact based parameter to either automatically guide the vehicle or to provide vehicle guidance information to a pilot.

2. The system of claim 1, wherein the control system is arranged to compare the at least one time-to-contact based parameter with a target time-to-contact based parameter.

3. The system of claim 1 or 2, wherein the control system comprises a display system arranged to display information related to the at least one time-to-contact based parameter to the pilot.

4. The system of claim 2, wherein the control system is arranged to use at least one the time-to-contact based parameter to drive software-generated display symbology on the display system.

5. The system of claim 3 or 4, wherein the display system is arranged to directly display the variance between the at least one time-to-contact based parameter and a target time-to-contact based parameter.

6. The system of claim 3 or 4, wherein the display system indicates the variance between the at least one time-to-contact based parameter and a target time-to-contact based parameter by indicating the predicted position of the vehicle, based on its current trajectory, at a moment in time in the future and by indicating the target position of the vehicle at the same moment in time in the future.

7. The system of claim 6, wherein the display system displays a target position indicator symbol and a predicted position indicator symbol, each indicator symbol being scaled to represent the forward position of the vehicle at the moment in time in the future.

8. The system of claim 7, wherein the indicator symbols are scaled such that, in at least one dimension, the size of the symbols corresponds to the actual size that a vehicle would be if it were positioned at the future position represented by the symbol, when viewed from the guided vehicle'"'"'s current position.

9. The system of any preceding claim, wherein the at least one time-to-contact based parameter comprises a rate of change of time-to-contact.

10. The system any preceding claim, wherein processor is arranged to couple the time-to-contact of two separate motion gaps.

11. The system of claim 10, wherein the time-to-contact of two separate gaps are linked by a coupling constant and the control system is arranged to compare the coupling constant with a target coupling constant.

12. The system of claim 10 or 11, wherein one of the time-to-contact parameters to be coupled comprises a general time-to-contact guide value.

13. The system of claim 12, wherein the processor provides the general time-to-contact guide value using the equation

${\tau }_{}$

G = t 

( T + t ) T + 2 

t .

14. The system of claim 12, wherein the processor provides the general time-to-contact guide value using the equation

${\tau }_{}$

g = 1 2 

( t - T 2 t ) .

15. The system of any preceding claim, wherein the control system is arranged to guide the vehicle or provide information to instruct the pilot to guide the vehicle in to close a gap between a current or projected position of the vehicle and a target position in a motion having a constant rate of change of time-to-contact.

16. The vehicle guidance system of claim 15, wherein the control system is arranged to guide the vehicle in a motion having a constant rate of change of time-to-contact between 0.6 and 0.8.

17. The vehicle guidance system of claim 15, wherein the control system is arranged to guide the vehicle in a motion having a constant rate of change of time-to-contact of approximately 0.6.

18. The system of any preceding claim, wherein the measurement system comprises a measurement system arranged to capture information relating to the optic flow with respect to a vehicle.

19. The system of any preceding claim, wherein the measurement system comprises at least one spatial variable measurement instrument and the processor is arranged to convert the measured spatial variables into a time-to-contact based parameter.

20. The system of any preceding claim wherein the vehicle is an aircraft and the system is an aircraft guidance system.

21. The system of claim 20, wherein the guidance system is an aircraft landing guidance system and the guidance system is arranged to guide the vehicle or provide information to instruct the pilot to guide the vehicle in a first motion having a rate of change of time-to-contact of 1 followed by a second motion having a rate of change of time-to-contact ({dot over (τ

)}) of between 0.6 and 0.8.

22. The system of claim 21, wherein the first motion is during the final approach of the aircraft and the second motion is during the flare.

23. The system of claim 21 or 22, wherein the control system comprises a display system on which a flight path vector symbol is generated.

24. The system of claim 21, wherein the flight path vector symbol indicates a target flight path of

${\gamma }_{}$

vc = θ

- 1 cos 



θ





cos 



φ

[ 1 U 

Δ





h 

h ¨

1 - c + sin 



θ

]

25. A vehicle guidance method comprising:

measuring information;

converting said information into a time-to-contact based parameter; and

using the time-to-contact based parameter to either automatically guide the vehicle or to provide vehicle guidance information to a pilot.