Lighting system with traffic management capabilities

• US 8,436,748 B2
• Filed: 06/18/2008
• Issued: 05/07/2013
• Est. Priority Date: 06/18/2007
• Status: Active Grant

• Current Assignee: LeddarTech, Inc.
• Original Assignee: LeddarTech, Inc.
• Inventors: Mimeault, Yvan, Cantin, Daniel
• Primary Examiner(s): Swarthout, Brent
• Application Number:
  US12/664,744
• Publication Number:
  US 20100194595A1
• Time in Patent Office: 1,784 Days
• Field of Search: 340/907, 340/917, 340/913, 340/916, 340/919, 340/925, 356/4.01, 356/5.01, 356/615, 250/208.2, 250/395, 250/221, 250/336.1, 250/338.1, 250/559.29, 701/36, 701/301
• US Class Current: 340/917
• CPC Class Codes: G01S 17/04 Systems determining the presence of a target
• CPC Class Codes: G01S 17/10 using transmission of interrupted, pulse-modulated waves determination of distance by phase measurements G01S17/32
• CPC Class Codes: G01S 17/58 Velocity or trajectory determination systems; Sense-of-movement determination systems
• CPC Class Codes: G01S 7/4808 Evaluating distance, position or velocity data
• CPC Class Codes: G08G 1/0104 Measuring and analyzing of parameters relative to traffic conditions
• CPC Class Codes: G08G 1/07 Controlling traffic signals
• CPC Class Codes: G08G 1/095 Traffic lights
• CPC Class Codes: Y02B 20/40 Control techniques providing energy savings, e.g. smart controller or presence detection

Abstract

The present lighting system adds detection capabilities to perceive the presence and measure the velocity of objects such as automobiles, trucks, pedestrian and other users, to lighting modules for transportation applications like traffic signal, pedestrian control, rails signal, street light, message board and speed monitoring board. For example, a Light Emitting Diode (LED) has the capability to be used as lighting source for illumination as a first function and also be pulsed or modulated as a source for the detection sub-system as a second function.

Claims

1. A method for controlling traffic signaling as a function of a detection of an object, said object being one of a vehicle, an automobile, a truck, a pedestrian, a particle, an airborne particle, a gas, a liquid and a user of a traffic light, the method comprising:

providing said traffic light with a visible-light source emitting visible light and having a function of actuating alternately at least two different traffic signal states for traffic signaling;

driving the visible-light source to emit light in a traffic signal state in a predetermined mode in a field of illumination, with visible light in the predetermined mode being emitted so as to be visible to an unaided human eye;

receiving a reflection/backscatter of the emitted visible light from said object located in said field of illumination;

identifying at least one of a presence and a position of the object as a function of the reflection/backscatter received and of the predetermined mode; and

controlling said traffic signal states actuated by the visible-light source as a function of the at least one of the presence and the position of the object.

2. The method according to claim 1, further comprising retrofitting an existing traffic light with a source controller for driving the visible-light source and a detector for receiving the reflection/backscatter of the emitted visible light from the object.

3. The method according to claim 1, wherein driving the visible-light source in the predetermined mode comprises at least one of pulsating and modulating the visible light.

4. The method according to claim 1, wherein receiving the reflection/backscatter comprises filtering given light wavelengths.

5. The method according to claim 1, wherein identifying at least one of a presence and a position of the object comprises calculating at least a distance of the object by measuring a time delay between emitting the visible light and receiving the reflection/backscatter from the object.

6. The method according to claim 5, wherein calculating the distance comprises continuously calculating the distance so as to calculate a speed of the object.

7. The method according to claim 1, further comprising:

providing an auxiliary light source in association with the traffic light;

driving the auxiliary light source concurrently with the visible-light source in another predetermined mode to emit auxiliary light in an auxiliary field of illumination;

receiving a reflection/backscatter of the auxiliary light from said object located in said auxiliary field of illumination;

identifying at least one of the presence and the position of the object as a function of at least the reflection/backscatter received from the auxiliary light and the predetermined modes; and

controlling said signal states actuated by the visible-light source as a function of at least one of the presence and the position of the object.

8. The method according to claim 7 wherein driving the auxiliary light source comprises driving the auxiliary light source into emitting light non-visible to an unaided human eye.

9. The method according to claim 1, wherein driving the visible-light source to emit visible light in a predetermined mode comprises pulsating a light emission diode to produce light pulses having a width of less than 50 ns.

10. The method according to claim 1, wherein controlling said traffic signal states comprises switching said traffic signal states as a function of the at least one of the presence and the position of the object.

11. A traffic-signal lighting system for controlling traffic signaling as a function of a detection of an object, said object being one of a vehicle, an automobile, a truck, a pedestrian, a particle, an airborne particle, a gas, a liquid and a user of a traffic light, the system comprising:

a light source emitting visible light and having a function of emitting visible light in an illumination mode for actuation alternately at least two traffic signal states;

a source controller for driving the light source into emitting one of the traffic signal states in a predetermined mode in a field of illumination, with visible light in the predetermined mode being emitted such that the light source maintains said function of emitting traffic signals visible to an unaided human eye in the environment while being driven by the source controller;

an optical detector adapted to detect the visible light as reflected/backscattered by said object located in said field of illumination to produce detection data; and

a data/signal processor for receiving detection data from the optical detector, the data/signal processor producing a data output associated to the object as a function of the predetermined mode and the detection data, and for commanding the light source into controlling said traffic signal states as a function of the data output.

12. The traffic-signal lighting system according to claim 11, further comprising an external traffic-management system connected to the data/signal processor for managing traffic as a function of the detection data received from the data/signal processor.

13. The traffic-signal lighting system according to claim 11, wherein the optical detector comprises a plurality of sub-detectors each detecting a specific zone.

14. The traffic-signal lighting system according to claim 11, further comprising a scanning mechanism in association with the optical detector so as to cause a scanning motion of a field of view of the optical detector within a range of illumination of emitted light of the light sources.

15. The traffic-signal lighting system according to claim 11, wherein the optical detector has an array of sub-detectors.

16. The traffic-signal lighting system according to claim 11, wherein the source controller comprises a pulse/modulation driver to drive the visible-light source in the predetermined mode.

17. The traffic-signal lighting system according to claim 11, wherein the source controller comprises an illumination driver to drive the light source into emitting light of suitable intensity to illuminate an environment.

18. The traffic-signal lighting system according to claim 16, wherein the light source has a plurality of lights, with at least one of the lights of the light source being driven by the illumination driver to illuminate the environment, while at least another one of the lights of the light source is driven by the pulse/modulation driver to emit the visible light in the predetermined mode.

19. The traffic-signal lighting system according to claim 11, wherein the optical detector has a filtering device to filter given light wavelengths of the reflected/backscattered visible light.

20. The traffic-signal lighting system according to claim 11, further comprising an auxiliary light source for emitting an auxiliary light in another predetermined mode concurrently with the visible-light source, the reflection/backscatter of the auxiliary light received from an object being used to produce said a data output associated to the object.

21. The traffic-signal lighting system according to claim 20, wherein the auxiliary light source comprises a non-visible light source.

22. The traffic-signal lighting system according to claim 11, wherein said light source comprises a light emitting diode light source.

23. The traffic-signal lighting system according to claim 11, wherein the data/signal processor commands the light source into switching said traffic signal states as a function of the data output.