Traffic light status remote sensor system

• US 7,495,579 B2
• Filed: 06/13/2005
• Issued: 02/24/2009
• Est. Priority Date: 06/13/2005
• Status: Expired due to Fees

• Current Assignee: Optotraffic, LLC
• Original Assignee: Sigma Space Corp.
• Inventors: Seas, Antonios, Mostofi, David, Sirota, J. Marcos
• Primary Examiner(s): La; Anh V
• Application Number:
  US11/151,377
• Publication Number:
  US 20070008176A1
• Time in Patent Office: 1,352 Days
• Field of Search: 340/425.5, 340/457, 340/474, 340/907, 340/904, 340/915, 340/931, 340/936, 340/937, 340/942, 340/641, 246/473.R, 246/1.C, 246/473.1, 246/473.2, 246/473.3, 246/477, 246/483, 246/484, 246/486, 250/339.02, 250/349, 250/559.11, 250/206, 250/208.1, 701/19, 347/238, 362/800, 324/414
• US Class Current: 340/907
• CPC Class Codes: G08G 1/0175 by photographing vehicles, e.g. when violating traffic rules
• CPC Class Codes: G08G 1/095 Traffic lights
• CPC Class Codes: G08G 1/097 Supervising of traffic control systems, e.g. by giving an alarm if two crossing streets have green light simultaneously

Abstract

A Traffic-Light Status Remote Sensor System is disclosed. The basic system consists of a set of lenses, detectors, and narrowband filters. The sensor system is capable of determining the status of a traffic light (red, amber, or green) from a distance, without any connection to the electronic boards controlling the traffic light. A portable red-light photo-enforcement system working independently from the traffic light controllers is a potential application of the remote traffic light sensor.

Claims

1. A transportable traffic photo-enforcement system comprising:

a remote sensor arranged to detect a status of a traffic control signaling device, and

a recording device incorporating at least one recording medium,

wherein the remote sensor and the recording device are collocated and supported by a common supporting structure, the remote sensor is arranged remotely in a line of sight of the traffic control signaling device, and the transportable traffic photo-enforcement system is arranged to have no wired connections or dedicated data conduits between the transportable traffic photo-enforcement system and the traffic control signaling device.

2. The transportable traffic photo-enforcement system of claim 1, wherein the remote sensor is arranged to observe the traffic control signal device having an unobstructed field of view substantially centered on the traffic control signal device, the field of view being at least two times an observed size of the traffic control signaling device.

3. The transportable traffic photo-enforcement system of claim 1, wherein the digital recording device includes a digital camera and the recording medium is a digital recording medium.

4. The transportable traffic photo-enforcement system of claim 3, wherein the digital camera includes a color CCD detector, the recording medium is a digital color image recording medium, and the color CCD detector and the recording medium are arranged to detect the status of the traffic control signaling device using a color of a plurality of pixels on at least one digital color image recorded on the digital color image recording medium.

5. The transportable traffic photo-enforcement system of claim 1, wherein traffic photo-enforcement system further comprises a speed sensor system arranged to measure a speed of vehicles participating in a traffic controlled by the traffic control signaling device.

6. The transportable traffic photo-enforcement system of claim 5, wherein the recording digital recording device further includes a Central Processor Unit arranged to receive a data set including the detected status of the traffic control signaling device and the speed measured by the speed sensor system, process the data set to generate a trigger for the recording device to initiate and store a series of recordings on the recording medium of a condition of the traffic regulated by the traffic control signal.

7. The transportable traffic photo-enforcement system of claim 6, wherein the Central Processor Unit is arranged to identify at least one vehicle associated with the speed measured by the speed sensor and the status of the traffic control signaling device, receive a data set on the detected status of the traffic control signaling device and the speed of the identified vehicle measured by the speed sensor system, process the data set to generate a trigger for the recording device to initiate and store the series of recordings on the recording medium of a relative position between traffic control signal and the identified vehicle as a function of time and the detected status of the traffic control signaling device.

8. A transportable traffic photo-enforcement system comprising:

a remote traffic light sensor arranged to detect a status of a traffic light, and

a recording device incorporating at least one recording medium,

wherein the remote sensor and the recording device are collocated and supported by a common supporting structure placed remotely in a line of sight of the traffic light having no wired connections or dedicated data conduits between the transportable traffic photo-enforcement system and the traffic light.

9. The transportable traffic photo-enforcement system of claim 8, wherein the remote traffic light sensor comprises:

a light detector,

at least one lens, and

a filter selected to allow a substantially single color light to pass therethrough,

wherein the light detector provides an output upon receiving the single color light.

10. The transportable traffic photo-enforcement system of claim 9, wherein the substantially single color light is selected from the group consisting of:

amber,

red, and

green.

11. The transportable traffic photo-enforcement system of claim 9, wherein the filter is placed between the light detector and the lens.

12. The transportable traffic photo-enforcement system of claim 9, wherein the lens is placed between the light detector and the filter.

13. The transportable traffic photo-enforcement system of claim 9, wherein the light detector is selected from the group consisting of:

a single element photo detector,

a multi-element photo detector,

a monochrome charge-coupled device video detector,

a and color charge-coupled device video detector.

14. The remote traffic light sensor of claim 8, comprising:

a first light detector and a second light detector,

at least one lens for each of the first light detector and the second light detector,

a first filter associated with the first light detector selected to allow a first substantially single color light to pass therethrough, and

a second filter associated with the second light detector selected to allow a second substantially single color light to pass therethrough, the second substantially single color light being different than the first substantially single color light,

wherein the first and the second light detectors provide an output upon receiving the first and the second substantially single color light respectively.

15. The remote traffic light sensor according to claim 14, wherein the first and second filters comprise narrowband filters.

16. The remote traffic light sensor according to claim 14, wherein at least one of the first and second filter is placed between its associated detector and lens.

17. The remote traffic light sensor according to claim 14, wherein the at least one lens for each of the first and second detector is placed between its associated detector and filter.

18. The remote traffic light sensor according to claim 14, wherein the first and the second filters are selected from the group consisting of:

a red light filter and a green light filter,

a red light filter and an amber light filter, and

an amber light filter and a green light filter.

19. The remote traffic light sensor according to claim 14, wherein the first and second detector is selected from the group consisting of:

a single element photo detector,

a multi-element photo detector,

a monochrome charge-coupled device video detector, and

a color charge-coupled device video detector.

20. The remote traffic light sensor according to claim 14, further comprising:

a third light detector,

at least one lens for the third light detector,

and a third filter associated with the third light detector selected to allow a third substantially single color light to pass therethrough, the third substantially single color light being different than the first and second substantially single color light,

wherein the first, second, and third light detectors provide an output upon receiving the substantially single color light.

21. A remote traffic light sensor of claim 8, comprising:

at least one lens,

a position sensitive detector,

and a three-circle reference,

wherein the three-circle reference is aligned to permit light from each of three traffic signal lights to pass through one of the circles before the light is detected by the position sensitive detector.

22. The remote traffic light sensor according to claim 21, wherein the position sensitive detector provides an output indicative of which light of the traffic signal is illuminated based upon the location of light in the three-circle reference.

23. A transportable traffic photo-enforcement method comprising:

arranging a remote sensor to detect a status of a traffic control signaling device and a collocated recording device, incorporating at least one recording medium and a Central Processor Unit, to be supported by a common transportable supporting structure in a line of sight of a traffic control signal device;

arranging a speed sensor to measure speed of at least one vehicle participating in a traffic controlled by the traffic control signal device;

establishing a data connection for data exchange between the Central Processing Unit and the speed sensor;

measuring speed of at least one vehicle identified as participating in a traffic controlled by the traffic control signal device and detecting the status of the traffic control signaling device;

sending a data set including the detected status of the traffic control signaling device and the speed of the identified vehicle to the Central Processing Unit;

processing the data set by the Central Processing Unit to generate a trigger for the recording device;

triggering the recording device and storing a series of recordings on the recording medium of a relative position between traffic control signal and the identified vehicle as a function of time and the detected status of the traffic control signaling device.

24. A transportable traffic photo-enforcement method of claim 23, wherein processing the data set by the Central Processing Unit comprises a calculation of a probability for the identified vehicle to violate traffic regulations based upon the status of the traffic control signal device, and wherein the trigger is generated according to the calculated probability.

25. A transportable remote traffic light status sensor calibration method comprising:

starting the sensor calibration procedure;

centering and recording an image of an entire traffic light onto a video CCD of the sensor;

aligning a three-circle reference to the recorded image;

setting the CCD video zoom so as the traffic light is at the center of the CCD video recording and its height occupies about half the size of the CCD;

balancing a color levels and a brightness intensity;

learning the light colors and positions by recording colors corresponding to each state of the traffic light and saving it as reference, and recording position of the three-circle reference;

ending the calibration procedure.

26. A transportable remote traffic light status sensor operation method comprising:

arranging remote traffic light status sensor to image a traffic light;

gating a digital image file of the traffic signal from the video CCD;

scanning a pixels corresponding to the digital image to determine the status of the traffic signal;

checking whether the red light is illuminated, and if the light is red then proceeding to verify the red-light status by checking a position of the red light relative to the entire digital image, and if the light is not red then proceeding to next step;

checking whether the amber light is illuminated, and if the light is amber then proceeding to verify the amber-light status by checking a position of the amber light relative to the entire digital image, and if the light is not amber then proceeding to next step;

checking whether the green light is illuminated, and if the light is green then proceeding to verify the green-light status by checking a position of the green light relative to the entire digital image, and if the light is not green then increasing a count of a counter by 1 and if the count is greater than a predetermined number generating a service request, if not then starting the operation again by getting a new digital image from the video CCD;

setting an recording an output to a state corresponding to the verified traffic signal state;

checking whether any service request has been issued, if yes then end, else proceeding to next stage;

clearing the contents of the counter;

starting the algorithm again by getting a new digital image from the video CCD.