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

• US 7,280,674 B2
• Filed: 05/28/2003
• Issued: 10/09/2007
• Est. Priority Date: 06/05/2001
• Status: Expired due to Fees

• 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
• Primary Examiner(s): Bali; Vikkram
• Assistant Examiner(s): BHATNAGAR, ANAND P
• Application Number:
  US10/448,172
• Publication Number:
  US 20030198271A1
• Time in Patent Office: 1,595 Days
• Field of Search: 382/100, 382/104, 372/25, 372/30, 362/507, 340/933, 701/301
• US Class Current: 382/104
• 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 roadway imaging between at least two oncoming motor vehicles, comprising the steps of:

selecting at least one repeating time slot for each of said motor vehicles based at least in part upon which roadway said motor vehicles are disposed and a coordinated time reference signal received by said motor vehicles, wherein said selected time slots for a first one of said motor vehicles and a second one of said oncoming motor vehicles are different;

triggering a light source mounted on each of said motor vehicles to emit periodic light pulses synchronized with said repeating time slots selected for each of said motor vehicles; and

receiving scattered light from objects being illuminated by said light source mounted on each of said motor vehicles in an imaging device of each of said motor vehicles during a gating period correlating to said repeating time slot selected for each of said motor vehicles.

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 each of said vehicles is disposed and selecting said time slot for each of said vehicles based at least in part upon said identified lane for each of said vehicles.

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

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 (2DS/c)+Δ

TPULSE, where Δ

TPULSE is a duration of at least one of said periodic light pulses, DS 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 vehicles are 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 a location and a direction of travel for each of said vehicles; and

processing said data using a database to determine said at least one repeating time slot for each of said vehicles.

8. The method of claim 7, wherein said received data is 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 coordinated time reference signal is a wirelessly propagated synchronization signal.

11. The method of claim 10, wherein said coordinated time reference 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 coordinated time reference signal.

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

14. A reduced glare roadway imaging system a motor vehicle, said reduced glare roadway imaging system comprising:

at least one light source for emitting periodic light pulses;

a synchronization receiver system configured for obtaining a coordinated time reference signal;

a processor for determining a repeating time slot based at least in part upon which roadway said motor vehicle is disposed and said obtained coordinated time reference signal, wherein said determined repeating time slot for said motor vehicle and one or more oncoming motor vehicles are different;

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

an imaging device for receiving light resulting from said light pulses being scattered by objects, said imaging device receiving said scattered light during a gating period correlating with said emissions of light pulses.

15. The system of claim 14, further comprising a display for presenting said received scattered light 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 (2DS/c)+Δ

TPULSE, where Δ

TPULSE is a duration of at least one of said periodic light pulses, DS 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 system which receives coordinates representing a location of said vehicle and a direction of travel of said vehicle, 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.