Device and method for object illumination and imaging using time slot allocation based upon road changes

• US 20030198271A1
• Filed: 05/28/2003
• Published: 10/23/2003
• Est. Priority Date: 06/05/2001
• Status: Active Grant

• Current Assignee: University of Florida Research Foundation, Incorporated (State University System of Florida)
• Original Assignee: University of Florida Research Foundation, Incorporated (State University System of Florida)
• Inventors: Matveev, Oleg
• Granted Patent: US 7,280,674 B2
• Time in Patent Office: Days
• US Class Current: 372/92
• CPC Class Codes: B60Q 1/14 having dimming means
• CPC Class Codes: B60Q 1/1415 Dimming circuits
• CPC Class Codes: G01S 17/18 wherein range gates are used
• CPC Class Codes: G01S 17/86 Combinations of lidar systems with systems other than lidar, radar or sonar, e.g. with direction finders
• CPC Class Codes: G01S 17/88 Lidar systems specially adapted for specific applications
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G01S 17/931 of land vehicles
• CPC Class Codes: G01S 19/14 specially adapted for specific applications
• CPC Class Codes: G01S 7/484 Transmitters
• CPC Class Codes: G01S 7/487 Extracting wanted echo signals , e.g. pulse detection
• CPC Class Codes: G01S 7/51 Display arrangements

Abstract

A reduced glare imaging system for motor vehicles. The reduced glare imaging system includes at least one light source capable of modulation, a synchronization system including structure for obtaining a time reference, and a processor for determining a fixed time based upon which roadway a motor vehicle is disposed. The fixed time can be used to determine a repeating time slot. The imaging system also includes a trigger for modulating emissions of periodic light pulses from the light source. Accordingly, the periodic light pulses can be synchronized with the repeating time slot. A receiver is also provided with the system for receiving radiation resulting from the light pulses being scattered by objects. The radiation can be received during a gating period which correlates to the light pulses. The radiation can be presented as images on a display.

Claims

1. A method of providing reduced glare imaging for motor vehicles, comprising the steps:

selecting at least one repeating time slot based at least in part upon which roadway a motor vehicle is disposed, said at least one repeating time slot being referenced to a timing signal;

triggering a light source mounted to said motor vehicle to emit periodic light pulses synchronized with said repeating time slot; and

receiving scattered light from objects being illuminated by said pulsed light source.

2. The method of claim 1, further comprising the step of processing said received scattered light to obtain imaging information to be displayed, said imaging information representing said illuminated objects.

3. The method of claim 1, wherein said selecting step further comprises the step of identifying in which lane of said roadway said vehicle is disposed and selecting said time slot based at least in part upon said identified lane.

4. The method of claim 1, wherein said selecting step further comprises the step of determining a direction of movement of said vehicle and selecting said time slot based at least in part upon said determined direction of movement.

5. The method of claim 1 further comprising the step of defining said time slot to have a duration at least as long as a duration of said gating period, wherein said duration of said gating period is approximately equal to the sum of (2D_S/c)+Δ

T_PULSE, where Δ

T_PULSE is a duration of at least one of said periodic light pulses, D_S is a desired illumination distance for the imaging system'"'"'s field of operation, and c is the speed of light.

6. The method of claim 1 wherein said selecting step further comprises the step of identifying said roadway in which said vehicle is disposed using at least one of a global positioning system, a local positioning system, a wide area augmentation system and a roadway indicator.

7. The method of claim 1, wherein said selecting step further comprises the steps of:

receiving data representing said vehicles location and direction of travel; and

processing said data using a database to determine said at least one repeating time slot.

8. The method of claim 7, wherein said data are received from at least one of a global positioning system, a local positioning system, a wide area augmentation system and a roadway indicator.

9. The method of claim 1, wherein said selecting step further comprises the step of receiving an RF signal transmitted by at least one of a global positioning system, a local positioning system, a wide area augmentation system and a roadway indicator which identifies said at least one repeating time slot.

10. The method of claim 1, wherein said timing signal is a wirelessly propagated synchronization signal.

11. The method of claim 10, wherein said timing signal is synchronized with Coordinated Universal Time (UTC).

12. The method of claim 1, further comprising the step changing said repeating time slot to a second repeating time slot upon losing a reception of said timing signal.

13. The method of claim 1, further comprising the step of changing said repeating time slot to a second repeating time slot upon the occurrence of at least one condition selected from the group consisting of said motor vehicle approaching an intersection and said motor vehicle changing roadways.

14. A reduced glare imaging system for motor vehicles, comprising:

at least one pulsed light source;

a synchronization system including structure for obtaining a time reference;

a processor for determining a repeating time slot based at least in part upon which roadway a motor vehicle is disposed;

a trigger for modulating emissions of periodic light pulses from said light source, said periodic light pulses being synchronized with said repeating time slot; and

a receiver for receiving radiation resulting from said light pulses being scattered by objects, said receiver receiving said radiation during a gating period correlating to said light pulses.

15. The system of claim 14, further comprising a display for presenting said radiation as images.

16. The system of claim 14, wherein said processor further evaluates which lane of said roadway said vehicle is disposed to determine said repeating time slot.

17. The system of claim 14, wherein processor further evaluates a direction of movement of said vehicle to determine said repeating time slot.

18. The system of claim 14, wherein said time slot has a duration at least as long as a duration of said gating period, wherein said duration of said gating period is approximately equal to the sum of (2D_S/c)+Δ

T_PULSE, where Δ

T_PULSE is a duration of at least one of said periodic light pulses, D_S is a desired illumination distance, and c is the speed of light.

19. The system of claim 14, wherein said roadway in which said vehicle is disposed is determined using at least one of a global positioning system, a local positioning system, a wide area augmentation system and a roadway indicator which identifies said at least one repeating time slot.

20. The system of claim 14, further comprising a receiver which receives coordinates representing said vehicles location and direction of travel, wherein said processor processes said coordinates using a database to determine said repeating time slot.

21. The system of claim 20, wherein said coordinates are received from at least one of a global positioning satellite and a local positioning system.

22. The system of claim 14, further comprising a receiver for receiving an RF signal transmitted by a roadway indicator which identifies said repeating time slot.

23. The system of claim 14, wherein said repeating time slot is changed to a second repeating time slot upon loss of reception of said time reference.

24. The system of claim 14, wherein said repeating time slot is changed to a second repeating time slot upon the occurrence of at least one condition selected from the group consisting of said motor vehicle approaching an intersection and said motor vehicle changing roadways.