System and method for signal light preemption and vehicle tracking

• US 6,232,889 B1
• Filed: 08/05/1999
• Issued: 05/15/2001
• Est. Priority Date: 08/05/1999
• Status: Expired due to Fees

• Current Assignee: Emery B. Dyer, Peter Apitz
• Original Assignee: Emery B. Dyer, Peter Apitz
• Inventors: Dyer, Emery B., Apitz, Peter
• Primary Examiner(s): TRIEU, VAN THANH
• Application Number:
  US09/368,736
• Time in Patent Office: 649 Days
• Field of Search: 340/902, 340/906, 340/907, 340/904, 340/916, 340/933, 340/935, 340/988, 340/990, 340/917, 701/117, 701/213, 701/225
• 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 system and method is provided for preempting the signal lights of an intersection. A magnetic heading of an emergency or other vehicle is measured using a mobile unit and adjusted to account for the magnetic interference of the vehicle. The magnetic heading is transmitted to a base unit installed at the intersection. Upon receiving a verified magnetic heading from a vehicle, the base unit preempts the normal operation of the signal lights to present a green light or other preferred display to the emergency vehicle Additionally the vehicle has a transmitter operating at a high frequency, which limits the range of the transmission. Thus, only the intersection to be preempted receives the transmission from the mobile unit. Also, a tester is provided to evaluate the function of the base unit and the mobile unit without interfering with the normal operation of the traffic signal. Also, the location, type and direction of other vehicles can be tracked even if the signal lights are not preempted.

Claims

1. A system for controlling passage of one or more vehicles through an intersection having signal lights such that the one or more vehicles may preempt the signal lights, the system comprising:

a mobile unit capable of being mounted in the one or more vehicles, wherein the mobile unit has a compass for measuring a magnetic heading of the one or more vehicles; and

a base unit capable of being connected to a controller of the signal lights of the intersection, the base unit being configured to adjust the magnetic heading received from the mobile unit by a number of degrees equal to the number of degrees that the intersection is offset from being aligned in a substantially North/South and East/West configuration, the base unit being configured to produce at least one output signal which is dependent on the adjusted magnetic heading of the one or more vehicles, wherein the at least one output signal is recevied by the controller which preempts the normal operation of the signal lights and causes the signal lights to respond in a prescribed manner to the one or more vehicles.

2. A system as defined in claim 1, wherein each of the one or more vehicles has a mobile unit.

3. A system as defined in claim 1, wherein the mobile unit further comprises:

a mobile processor for processing the magnetic heading produced by the compass; and

a transmitter for transmitting the magnetic heading to the base unit.

4. A system as defined in claim 3, wherein the mobile processor produces a packet comprising the magnetic heading, a header, a message identification, a caller identification, priority bits and a checksum.

5. A system as defined in claim 4, wherein the transmitter transmits the packet to the base unit.

6. A system as defined in claim 1, wherein the magnetic heading is repeatedly computed and transmitted to the base unit.

7. A system as defined in claim 1, wherein the base unit further comprises:

a receiver for receiving a transmission from the mobile unit; and

a base processor for processing the transmission.

8. A system as defined in claim 7, wherein the transmission comprises the packet.

9. A system as defined in claim 1, wherein the base unit interprets the adjusted magnetic heading as:

(i) North if the adjusted magnetic heading is between about 315 degrees and 45 degrees;

(ii) East if the adjusted magnetic heading is between about 45 degrees and about 135 degrees;

(iii) South if the adjusted magnetic heading is between about 135 degrees and 225 degrees; and

(iv) West if the adjusted magnetic heading is between 225 degrees and 315 degrees.

10. A system as defined in claim 1, wherein the mobile unit transmits at a frequency approximately between 900 MHZ and 925 MHZ.

11. A system as defined in claim 1, further comprising a tester, wherein the tester evaluates the function of the base unit and the mobile unit.

12. A system as defined in claim 11, wherein the tester does not interfere with the normal operation of the signal lights.

13. A system as defined in claim 1, wherein the base unit is capable of sending logging information.

14. A system as defined in claim 13, wherein the logging information includes a location of the one or more vehicles and a type of the one or more vehicles.

15. A system as defined in claim 1, wherein the base unit further comprises at least one communication port.

16. A system as defined in claim 15, wherein the at least one communication port is used to transmit the logging information.

17. A system for preempting the signal lights of an intersection for an approaching vehicle, the system comprising:

a mobile unit capable of being mounted in the vehicle, the mobile unit comprising;

a compass for measuring a magnetic heading of the vehicle;

a mobile processor for processing the magnetic heading in preparation for transmission;

a transmitter for transmitting a packet, wherein the packet contains, at a minimum, the magnetic heading; and

a base unit comprising;

a receiver for receiving the packet;

a base processor for processing the packet, wherein the magnetic heading is adjusted by a number of degrees equal to the number of degrees that the physical orientation of the intersection is offset from being aligned in a substantially North/South and East/West,

the base processor using the adjusted magnetic heading to produce at least one output signal that preempts the signal lights, whereby the signal lights respond in a prescribed manner to the vehicle.

18. A system as defined in claim 17, wherein the packet further comprises:

a header byte, a message identification, a caller identification and priority bits.

19. A system as defined in claim 17, wherein the transmitter transmits at a frequency approximately ranging between 900 MHZ and 925 MHZ.

20. A system as defined in claim 17, wherein the magnetic heading is represented in degrees.

21. A system as defined in claim 17, wherein the magnetic heading is repeatedly measured and transmitted.

22. A system as defined in claim 17, wherein the base unit is electrically connected to a controller of the signal lights, wherein the controller receives the at least one control signal and causes the signal lights to be preempted.

23. A system as defined in claim 17, wherein the controller, upon receiving the at least one output signal from the base unit, interrupts the normal operation of the signal lights and causes a green light to be presented to the one or more vehicles.

24. A system as defined in claim 17, further comprising a tester, wherein the tester permits the function and operation of the mobile unit and the base unit to be evaluated without altering the normal operation of the signal lights.

25. A system as defined in claim 17, wherein the base unit further comprises at least one communication port.

26. A system as defined in claim 25, wherein the at least one communication port is used to send logging information to a remote location.

27. A system for preempting the normal operation of a signal light of an intersection to permit one or more emergency vehicles to have the signal light respond to the one or more emergency vehicles in a prescribed manner at the intersection, the system comprising:

a mobile unit capable of being attached to the one or more emergency vehicles, wherein the mobile unit measures a magnetic heading of the one or more emergency vehicles and processes the magnetic heading to produce a packet containing the magnetic heading;

a transmitter for transmitting the packet to a base unit, wherein the base unit processes the packet to retrieve the magnetic heading and adjusts the magnetic heading by a number of degrees equal to the number of degrees that the intersection is offset from being aligned in a substantially North/South and East/West configuration, the base unit being configured to produce at least one output signal which preempts the signal light such that the signal light responds in a prescribed manner to the one or more emergency vehicles.

28. A system as defined in claim 27, wherein the mobile unit further comprises:

a compass which measures the magnetic heading of the one or more emergency vehicles; and

a mobile processor which receives the magnetic heading from the compass and processes the heading to account for the magnetic error caused by the one or more vehicles.

29. A system as defined in claim 27, wherein the mobile unit repeatedly measures the magnetic heading, processes the magnetic heading, produces a packet and transmits the packet to the base unit.

30. A system as defined in claim 29, wherein the packet is produced and transmitted approximately 5 times per second.

31. A system as defined in claim 27, wherein the base unit comprises a receiver for receiving the packet from the transmitter.

32. A system as defined in claim 27, wherein the base unit comprises a base processor for processing the packet.

33. A system as defined in claim 32, wherein the base processor alters the magnetic heading contained in the packet to account for the physical orientation of the intersection being preempted by the one or more vehicles.

34. A system as defined in claim 27, wherein the packet further comprises:

a header byte, a message identification, a caller identification and priority bits, and a checksum.

35. A system as defined in claim 27, wherein only the intersection nearest the one or more vehicles is preempted.

36. A system as defined in claim 27, further comprising a tester, wherein the tester tests the operation and function of the mobile unit and the base unit without interfering with the normal operation of the signal lights.

37. A system as defined in claim 27, wherein the base unit further comprises one or more communication ports.

38. A system as defined in claim 37, wherein at least one of the one or more communication ports is used to transmit logging information to a remote location.

39. A method for preempting signal lights at an intersection, the method comprising the steps of:

measuring a magnetic heading of one or more vehicles;

transmitting the magnetic heading to a base unit installed at the intersection to be preempted;

altering the magnetic heading at the base unit to account for the physical orientation of the intersection by adjusting the magnetic heading of the one or more vehicles by a number of degrees equal to the number of degrees that the intersection is offset from being aligned in a substantially North/South and East/West configuration; and

producing at least one control signal according to the adjusted magnetic heading which preempts the signal lights and causes the signal lights to respond in a prescribed manner to the one or more vehicles.

40. A method as defined in claim 39, wherein the step of measuring a magnetic heading further comprises the step of altering the magnetic heading to account for the metal of the one or more vehicles.

41. A method as defined in claim 39, wherein the step of transmitting the magnetic heading further comprises the step of transmitting:

a header byte, a message identification, a caller identification, priority data, and a check sum.

42. A computer-readable medium having computer-executable instructions for executing the steps recite in claim 39.

43. A system for controlling the signal lights of an intersection comprising:

a mobile unit comprising;

means for discriminating a direction of travel of a vehicle; and

a transmitter for transmitting a transmission which includes the direction of travel of the vehicle; and

a base unit comprising;

a receiver for receiving the transmission;

a processor in communication with a plurality of dip switches configured to adjust the direction of travel of the vehicle received from the mobile unit by a number of degrees equal to the number of degrees that the intersection is offset from being aligned in a substantially North/South and East/West configuration; and

means for preempting signal lights, whereby the signal lights respond in a prescribed manner to the vehicle at the intersection.

44. A system as defined in claim 43, wherein the means for discriminating a direction of travel comprises a compass.

45. A system as defined in claim 44, wherein the means for discriminating a direction of travel further comprises a mobile processor which processes the direction of travel to account for the magnetic influence of the vehicle.

46. A system as defined in claim 43, wherein the transmission further includes caller identification and priority data.

47. A system as defined in claim 43, wherein the one or more dip switches represent the degree that the intersection is offset from the substantially North/South and East/West configuration.

48. A system as defined in claim 43, wherein the means for preempting the signal lights produces at least one control signal which is interpreted by a controller of the intersection such that the signal lights are preempted.

49. A system as defined in claim 43, wherein the means for preempting the signal lights further comprises at least one communication port, wherein at least one of the at least one communication port is capable of transmitting logging information to a remote location.

50. A system for tracking at a remote location one or more vehicles, the system comprising:

a mobile unit capable of being mounted in the one or more vehicles, the mobile unit comprising;

a compass for measuring a magnetic heading of the one or more vehicles;

a transmitter for transmitting a packet, wherein the packet contains, at a minimum, the magnetic heading; and

a base unit comprising;

a base processor for processing the packet, wherein the magnetic heading is adjusted by a number of degrees equal to the number of degrees that the intersection is offset from being aligned in a substantially North/South and East/West configuration, such that a direction of travel of the one or more vehicles is known; and

at least one communication port, wherein the at least one communication port is used to transmit information representative of at least one of the one or more vehicles and the intersection to the remote location.

51. A system as defined in claim 50, wherein the packet further comprises information selected from the group consisting of (i) the type of the one or more vehicle;

(ii) physical orientation of the intersection; and

(iii) a vehicle identification.

52. A system as defined in claim 50, wherein the logging information comprises:

the packet, and the location of the intersection.

53. A system for tracking one or more vehicles, the system comprising:

a mobile unit capable of being attached to the one or more vehicles, wherein the mobile unit measures a magnetic heading of the one or more vehicles and processes the magnetic heading to produce a direction of travel;

a processor for producing a packet comprising, at a minimum, the direction of travel, a type of vehicle, and an identification of the one or more vehicles;

a mobile transmitter for transmitting the packet to a base unit, wherein the base unit comprises at least one communication port;

a base processor for processing the direction of travel to obtain the magnetic heading and adjusting the magnetic heading received from the mobile unit by a number of degrees equal to the number of degrees that the intersection is offset from being aligned in a substantially North/South and East/West configuration, the base unit being configured to produce logging information, wherein the logging information comprises, at a minimum, the packet and the location of an intersection; and

a base transmitter connected to the at least one communication port, for transmitting the logging information to a remote location, whereby the one or more vehicles are tracked.

54. A system as defined in claim 53, wherein the vase unit produces one or more output signals capable of preempting a signal light.