Systems and method for controlling preemption of a traffic signal

• US 8,884,783 B2
• Filed: 02/24/2011
• Issued: 11/11/2014
• Est. Priority Date: 02/24/2011
• Status: Active Grant

• Current Assignee: Global Traffic Technologies LLC (Vontier Corp.)
• Original Assignee: Global Traffic Technologies LLC (Vontier Corp.)
• Inventors: Roberts, Douglas Gordon, Johnson, Jerry Lee
• Primary Examiner(s): POPE, DARYL C
• Application Number:
  US13/034,211
• Publication Number:
  US 20120218126A1
• Time in Patent Office: 1,356 Days
• Field of Search: 340/902, 340/904, 340/924, 340/994, 340/995.17
• US Class Current: 340/906
• CPC Class Codes: G08G 1/087 Override of traffic control, e.g. by signal transmitted by an emergency vehicle

Abstract

A priority control unit is provided for use with light-based and GPS-based traffic control priority systems. The priority control unit includes a light emitter subsystem that is configured to emit pulses of light. The pulses of light encode a priority request for activating preemption of a traffic signal by a light-based traffic control priority system. The priority control unit also includes a GPS-based subsystem that is configured to transmit a priority request by radio waves. The priority request from the GPS-based subsystem is for activating preemption of a traffic signal by a GPS-based traffic control priority system. A switch is coupled to the light emitter subsystem and to the GPS-based subsystem. The switch simultaneously activates both the light emitter subsystem and the GPS-based subsystem for transmitting priority requests in response to user control. In another embodiment, the priority control unit further includes a broadcast based subsystem for transmitting priority requests.

Claims

1. A priority control unit for use with light-based and GPS-based traffic control priority systems, wherein the light-based traffic control priority system activates preemption of a traffic signal in response to pulses of light encoding a priority request, and the GPS-based traffic control priority system activates preemption of a traffic signal in response to a radio signal encoding a priority request, comprising:

a light emitter subsystem configured to emit pulses of light that encode a priority request for activating preemption of a traffic signal by the light-based traffic control priority system;

a GPS-based subsystem configured to transmit a priority request by radio waves, the priority request for activating preemption of a traffic signal by the GPS-based traffic control priority system;

a shared communications bus coupled to the light emitter subsystem and to the GPS-based subsystem; and

a switch coupled to the light emitter subsystem and to the GPS-based subsystem, wherein the switch simultaneously activates both the light emitter subsystem and the GPS-based subsystem for transmitting priority requests in response to user control.

2. The priority control unit of claim 1, further comprising:

a broadcast subsystem that transmits a priority request to a centralized control system; and

wherein the switch is coupled to the broadcast subsystem and simultaneously activates the broadcast subsystem with the light emitter subsystem and the GPS-based subsystem.

3. The priority control unit of claim 1, wherein the light emitter subsystem and the GPS-based subsystem are configurable via the shared communications bus.

4. The priority control unit of claim 1, wherein:

the light emitter subsystem and the GPS-based subsystem are configurable with respective identifier codes via the shared communications bus; and

the light emitter subsystem and the GPS-based subsystem transmit the respective identifier codes in respective priority requests.

5. The priority control unit of claim 1, further comprising:

a broadcast subsystem coupled to the shared communication bus and configured to transmit a priority request to a centralized control system;

wherein the switch is coupled to the broadcast subsystem and simultaneously activates the broadcast subsystem with the light emitter subsystem and the GPS-based subsystem.

6. The priority control unit of claim 5, wherein:

the light emitter subsystem, the GPS-based subsystem, and the broadcast subsystem are configurable with respective identifier codes via the shared communications bus; and

the light emitter subsystem, the GPS-based subsystem, and the broadcast subsystem transmit the respective identifier codes in respective priority requests.

7. The priority control unit of claim 1, wherein the light emitter subsystem includes a plurality of LEDs.

8. The priority control unit of claim 7, wherein the LEDs are infrared LEDs.

9. The priority control unit of claim 7, wherein the LEDs include a plurality of visible light LEDs and a plurality of infrared LEDs.

10. The priority control unit of claim 1, wherein the light-based traffic control priority system includes a receiver with a photodetector and circuitry that produces a number of electrical pulses in response to each detected light pulse, wherein for each detected light pulse the number of electrical pulses represents a level of radiant power of the light pulse, and a threshold number of electrical pulses and an activation frequency at which the threshold number of electrical pulses is repeated activates preemption, further comprising:

wherein the light emitter subsystem includes;

a light emitter; and

control circuitry coupled to the light emitter and controlling the light emitter to emit bursts of light pulses, wherein each burst includes at least two light pulses and a frequency of light pulses in each burst and a frequency of the bursts cause the receiver to produce at least the threshold number of electrical pulses at the activation frequency and activate the preemption.

11. A method for generating priority requests to light-based and GPS-based traffic control priority systems, wherein the light-based traffic control priority system activates preemption of a traffic signal in response to pulses of light encoding a priority request, and the GPS-based traffic control priority system activates preemption of a traffic signal in response to a radio signal encoding a priority request, comprising:

simultaneously activating both a light emitter subsystem and a GPS-based subsystem in response to a single user control;

emitting pulses of light by the light emitter subsystem, the pulses of light encoding a priority request for activating preemption of a traffic signal by the light-based traffic control priority system;

transmitting a priority request via radio waves by the GPS-based subsystem, the priority request for activating preemption of a traffic signal by the GPS-based traffic control priority system; and

configuring the light emitter subsystem and the GPS-based subsystem via a shared communications bus that is coupled to the light emitter subsystem and to the GPS-based subsystem.

12. The method of claim 11, further comprising:

simultaneous with activating the light emitter subsystem and the GPS-based subsystem, activating a broadcast-based subsystem; and

transmitting a priority request by the broadcast-based subsystem.

13. The method of claim 11, further comprising:

wherein the light emitter subsystem and the GPS-based subsystem are configurable with respective identifier codes via the shared communications bus; and

transmitting the respective identifier codes in respective priority requests from the light emitter subsystem and the GPS-based subsystem.

14. A system for generating priority requests to light-based and GPS-based traffic control priority systems, wherein the light-based traffic control priority system activates preemption of a traffic signal in response to pulses of light encoding a priority request, and the GPS-based traffic control priority system activates preemption of a traffic signal in response to a radio signal encoding a priority request, comprising:

means for simultaneously activating both a light emitter subsystem and a GPS-based subsystem in response to a single user control;

means for emitting pulses of light by the light emitter subsystem, the pulses of light encoding a priority request for activating preemption of a traffic signal by the light-based traffic control priority system;

means for transmitting a priority request via radio waves by the GPS-based subsystem, the priority request for activating preemption of a traffic signal by the GPS-based traffic control priority system; and

a shared communications bus coupled to the light emitter subsystem and to the GPS-based subsystem.

15. The system of claim 14, further comprising:

wherein the means for simultaneously activating both the light emitter subsystem and the GPS-based subsystem includes means for simultaneously activating a broadcast subsystem along with the light emitter subsystem and the GPS-based subsystem;

means for transmitting a priority request by the broadcast subsystem to a centralized control system.