Traffic light signal system using radar-based target detection and tracking

1. A signaling system, comprising;

a traffic signal controller adapted to couple to a traffic control indicator, the traffic signal controller adapted to control different states of the traffic control indicator;

a signal state information module having a state of a traffic control indicator;

an RF transmitter operable to transmit signals toward at least one object/vehicle target;

an RF receiver operable to receive reflected signals from at least one said object/vehicle target; and

a radar/traffic processor coupled to the traffic signal controller and the signal state information module, and adapted to receive signals from the RF receiver;

the radar/traffic processor having an algorithm operable to determine characteristics of the object/vehicle targets and dynamically cause the traffic signal controller to control a state of the traffic control indicator in response thereto.

2. The signaling system of claim 1 , further comprising at least one traffic control indicator adapted to control traffic at a pre-determined roadway location; and

the traffic control indicator controlled by the traffic signal controller.

3. The signaling system of claim 1 , further comprising:

the algorithm of the radar/traffic processor being adapted to determine, in advance, a likelihood that an object/vehicle target will run a red light generated by the traffic control indicator;

the algorithm causing the traffic signal controller to maintain the status of an opposing traffic control indicator based on the probability of an object/vehicle target running a red light.

4. The signaling system of claim 1 , further comprising:

the algorithm of the radar/traffic processor being adapted to determine, in advance, a likelihood that a first object/vehicle target will make a left turn toward an opposing second object/vehicle target; and

the algorithm causing the traffic signal controller to illuminate a warning on a traffic control indicator to the left turning first object/vehicle target.

5. The signaling system of claim 1 , further comprising:

the algorithm of the radar/traffic processor being adapted to determine, in advance, a nature of the flow of approaching object/vehicle targets; and

the algorithm causing the traffic signal controller to extend a green light given to the flow of approaching object/vehicle targets so as to permit the uninterrupted traversal of the flow of object/targets through the intersection.

6. The signaling system of claim 1 , further comprising:

a sensor adapted to sense one or more of the following parameters: precipitation, time of day and temperature; and

the algorithm of the radar/traffic processor adapted to dynamically adjust its signals to the traffic signal controller based on the sensed parameters.

7. The signaling system of claim 1 , wherein the radar/traffic processor of a first traffic control indicator is in communication with at least one other radar/traffic processor controlling a second traffic control indicator in order to coordinate the signal status of the traffic control indicators.

8. The signaling system of claim 1 , wherein the radar/traffic processor is adapted to log traffic information.

9. The signaling system of claim 8 , wherein the logged information is communicated to an application.

10. The signaling system of claim 9 , wherein the logged information is communicated to the application by way of a data communication channel.

11. The signaling system of claim 1 , wherein the RF transmitter and the RF receiver comprise a radar.

12. The signaling system of claim 11 , wherein the radar utilizes LFM-CW radio-frequency signals.

13. The signaling system of claim 11 , wherein the radar implements a multi-stage spectral processing algorithm to determine distance, velocity and return-signal magnitude of at least one object/vehicle target.

14. The signaling system of claim 13 , further comprising a VCO within the radar operable to transmit an LFM-CW radio-frequency signal.

15. The signaling system of claim 14 wherein, the frequency of the VCO signal appears as a linear ramp on a plot of frequency versus time.

16. The signaling system of claim 15 , wherein a frequency difference between the transmitted and received radar signals from a single return is a function of an object/vehicle target's distance and velocity.

17. The signaling system of claim 16 , further comprising a mixer and low pass filter within the radar operable to extract the frequency difference between a transmitted and received signal by mixing the transmitted and received signal together and then performing a low pass filter operation.

18. The signaling system of claim 17 , further comprising a supplemental high pass filter being operable to equalize signals from object/vehicle targets at long range experiencing a large propagation loss with a result that a given object/vehicle target will appear with roughly the same power level at any distance.

19. The signaling system of claim 11 , wherein the radar is operable to generate a plurality of ramps with a steep slope having small ramp time.

20. The signaling system of claim 19 , wherein the radar is operable to detect both positive and negative velocities.

21. The signaling system of claim 19 , wherein the radar implements a multi-stage spectral processing algorithm comprised of fast Fourier transforms (“FFTs”).

22. The signaling system of claim 21 , further comprising a digital signal processor (“DSP”) performing the FFTs.

23. The signaling system of claim 11 , in combination with a high-level tracker module coupled to the output of the radar and to the input of the radar/traffic processor.

24. The signaling system of claim 23 , wherein the high-level tracker is adapted to process results from several radar observations spaced over time to further refine the estimates made by the radar/traffic processor.

25. The signaling system of claim 23 , wherein the high-level tracker is adapted to predict the location of at least one object/vehicle target.

26. The signaling system of claim 25 , wherein the prediction is based on the computed acceleration of an object/vehicle target.

27. The signaling system of claim 25 , wherein the prediction is based on the computed velocity of the object/vehicle target.

28. The signaling system of claim 23 , wherein the high-level tracker is adapted to generate and assign a confidence factor to an object/vehicle target which reflects the probability that the detected object/vehicle target is valid.

29. The signaling system of claim 28 , wherein the high level tracker assigns a high confidence factor to object/vehicle targets producing strong radar returns.

30. The signaling system of claim 11 , wherein the traffic signal controller and the radar/traffic processor are located in a controller cabinet and the radar is located on a mast arm.

31. The signaling system of claim 11 , wherein the radar and radar/traffic processor are located in a traffic control indicator housing.

32. The signaling system of claim 31 , wherein the radar/traffic processor and the radar are physically coupled together at a base of a traffic control indicator.

33. The signaling system of claim 11 , wherein the traffic control indicator and the radar are housed in a common housing.

34. The signaling system of claim 11 , wherein the radar is adapted to determine a position of the object/vehicle target relative to the radar.

35. The signaling system of claim 11 , wherein the radar is adapted to determine a distance of at least one object/vehicle target approaching the intersection.

36. The signaling system of claim 11 , wherein the radar is adapted to determine both a velocity and distance of multiple object/vehicle targets relative to a traffic control indicator.

37. The signaling system of claim 11 , wherein the radar is adapted to determine velocity and distance of object/vehicle targets in multiple lanes of traffic approaching a traffic control indicator.

38. The signaling system of claim 11 , wherein the radar is adapted to determine a change in the velocity of an object/vehicle target approaching the intersection.

39. The signaling system of claim 11 , further comprising the traffic signal controller controlling a traffic control indicator as a function of the radar and algorithm of the radar/traffic processor.

40. The signaling system of claim 11 , wherein the radar/traffic processor is adapted to cause a traffic control indicator to generate an alert upon the occurrence of a pre-determined event.

41. The signaling system of claim 40 , wherein the pre-determined event is an object/vehicle target entering an intersection within a pre-determined time frame.

42. The signaling system of claim 40 , wherein the pre-determined event is the high probability of an object/vehicle target running a red light.

43. The signaling system of claim 11 , further comprising a traffic control indicator adapted to display an alert indicative of an object/vehicle target being likely to run a red light.

44. An apparatus for controlling a traffic intersection, comprising;

a traffic signal controller coupled to a traffic control indicator, adapted to change states of the traffic control indicator;

a radar operable to receive signals from a plurality of object/vehicle targets;

a signal state information module having a state of a traffic control indicator;

a radar/traffic processor coupled to the traffic signal controller and signal state information module and adapted to receive signals from the radar;

the radar/traffic processor having an algorithm operable to determine characteristics of the object/vehicle targets and dynamically cause the traffic signal controller to control the states of the traffic control indicator in response thereto.

45. The apparatus of claim 44 , further comprising at least one traffic control indicator adapted to control traffic at a roadway intersection.

46. The apparatus of claim 44 , wherein the radar transmits an LFM-CW radio-frequency signal.

47. The apparatus of claim 39 , wherein the radar implements a multi-stage spectral processing algorithm.

48. The apparatus of claim 42 , wherein the multi-stage spectral processing algorithm is comprised of FFTs.

49. A method for determining if an object/vehicle target will enter an intersection including at least one traffic control indicator, comprising:

receiving a radar echo response indicating the object/vehicle target is approaching the intersection;

determining a range of the object/vehicle target and a velocity of the object/vehicle target; and

based on the object/vehicle range and velocity, determining if the object/vehicle target will enter the intersection; and

wherein the intersection comprises a plurality of the traffic control indicators at the intersection, and the traffic control indicators are a relational distance from one another.

50. The method of claim 49 further comprising based on the object/vehicle range and velocity determination, determining whether the traffic control indicator should re-sequence.

51. The method of claim 50 , further comprising performing at least one of a following re-sequence functionality from a group consisting of:

changing a color state of the traffic control indicator;

changing a color state of other traffic control indicators;

changing a directional signal of the traffic control indicator;

changing a directional signal of other traffic control indicators;

changing a color state of a directional signal of the traffic control indicator;

changing a color state of a directional signal of other traffic control indicators;

applying a visual alerting via the traffic control indicator;

applying a visual alerting via other traffic control indicators;

delaying a changing of a color state of the traffic control indicator;

delaying a changing of a color state of other traffic control indicators;

delaying a changing of a directional signal of the traffic control indicator;

delaying a changing of a directional signal of other traffic control indicators;

delaying a changing of a color state of a directional signal of the traffic control indicator;

delaying a changing of a color state of a directional signal of other traffic control indicators;

delaying an applying of a visual alerting via the traffic control indicator; and

delaying an applying of a visual alerting via other traffic control indicators.

52. The method of claim 51 further comprising performing at least one of the re-sequence functionality in at least one of a following location from a group consisting of:

a traffic intersection comprising the traffic control indicator; and

a traffic intersection comprising other traffic control indicators.

53. A method for determining if an object/vehicle target will enter an intersection including a traffic control indicator, comprising:

receiving a radar echo response indicating the object/vehicle target is approaching the intersection;

determining a range of the object/vehicle target and a velocity of the object/vehicle target; and

based on the object/vehicle range and velocity, determining if the object/vehicle target will enter the intersection; and

further comprising comparing the received radar echo response to a pre-existing traffic model that represents a satisfactory condition.

54. The method of claim 53 , wherein the satisfactory condition comprises an object/vehicle target approaching at least one of a following element from a group consisting of:

the traffic control indicator; and

the intersection;

at a distance that would avoid entering the intersection during at least one of a following event from a group consisting of:

a red state of illumination of the traffic control indicator; and

an impending red state of illumination of the traffic control indicator.

55. The method of claim 53 , wherein the satisfactory condition comprises an object/vehicle target approaching at least one of a following element from a group consisting of:

the traffic control indicator; and

the intersection;

at a velocity that would avoid entering the intersection during at least one of a following event from a group consisting of:

a red state of illumination of the traffic control indicator; and

an impending red state of illumination of the traffic control indicator.

56. The method of claim 53 , wherein the satisfactory condition comprises an object/vehicle target approaching at least one of a following element from a group consisting of:

the traffic control indicator; and

the intersection;

on a condition of a road that would avoid entering the intersection during at least one of a following event from a group consisting of:

a red state of illumination of the traffic control indicator; and

an impending red state of illumination of the traffic control indicator.

57. The method of claim 53 , wherein the satisfactory condition comprises an object/vehicle target approaching at least one of a following element from a group consisting of:

the traffic control indicator; and

the intersection;

in a type of weather that would avoid entering the intersection during at least one of a following event from a group consisting of:

a red state of illumination of the traffic control indicator; and

an impending red state of illumination of the traffic control indicator.

58. The method of claim 53 , wherein the satisfactory condition comprises an object/vehicle target approaching at least one of a following element from a group consisting of:

the traffic control indicator; and

the intersection;

in a traffic condition that would avoid entering the intersection during at least one of a following event from a group consisting of:

a red state of illumination of the traffic control indicator; and

an impending red state of illumination of the traffic control indicator.

59. The method of claim 53 , wherein the satisfactory condition comprises an object/vehicle target approaching at least one of a following element from a group consisting of:

the traffic control indicator; and

the intersection;

at a time that would avoid entering the intersection during at least one of a following event from a group consisting of:

a red state of illumination of the traffic control indicator; and

an impending red state of illumination of the traffic control indicator.

60. The method of claim 53 , further comprising comparing the received to a pre-existing traffic model on at least one of a following basis:

continually;

intermittently;

based on the determining; and

based on a specific event.

61. A method for determining if an object/vehicle target will enter an intersection including a traffic control indicator, comprising:

receiving a radar echo response indicating the object/vehicle target is approaching the intersection;

determining a range of the object/vehicle target and a velocity of the object/vehicle target; and

based on the object/vehicle range and velocity, determining if the object/vehicle target will enter the intersection;

further comprising determining the red state of illumination by performing at least one of a following action from a group consisting of:

measuring a voltage across a traffic signal controller load switch;

monitoring a traffic signal controller serial bus;

sensing voltages on a conflict monitor; and

using a photo sensor to directly detect light from the activated traffic signal

further comprising monitoring a state of illumination of a traffic control indicator in order to determine at least one of a following attribute from a group comprising:

a color of the state of illumination; and

a length of time of the state of illumination;

wherein such determination is used in determining if the object/vehicle target will enter the intersection; and

further comprising monitoring a state of illumination of a plurality of traffic control indicators.

62. The method of claim 61 , wherein the determining if the object/vehicle target will enter the intersection comprises:

determining if a traffic control indicator is in a state that is predeterministic for a red-light run; and

the object/vehicle target, as indicated by the radar echo response, is approaching the intersection in a manner that could improperly place the object/vehicle target in the intersection during at least one of a following event from a group consisting of:

a red state of illumination of the traffic control indicator; and

an impending red state of illumination of the traffic control indicator.

63. The method of claim 61 , further comprising determining a probability of running a traffic control indicator in a red state of illumination based upon at least one of a following factor from a group consisting of:

a distance of the object/vehicle target;

a velocity of the object/vehicle target;

a road condition;

a traffic condition;

an intersection condition;

a type of weather;

a time of day; and

a time of night.

64. The method of claim 61 , further comprising overriding the traffic signal controller by a traffic light control system.

65. The method of claim 64 , wherein the overriding comprises at least one of a following element from a group consisting of:

changing other traffic control indicators to a different state of illumination;

changing other traffic control indicators to a visual signal that indicates an anomaly condition;

holding other traffic control indicators at a given state of illumination; and

holding other traffic control indicators at a visual signal that indicates an anomaly condition.