Grid-based trasnmission system

• US 20070073483A1
• Filed: 11/14/2003
• Published: 03/29/2007
• Est. Priority Date: 04/28/2003
• Status: Active Grant

• Current Assignee: St Electronics Pte Limited (Singapore Technologies Engineering Limited)
• Original Assignee: St Electronics Pte Limited (Singapore Technologies Engineering Limited)
• Inventors: Tzidon, Aviv
• Granted Patent: US 7,904,242 B2
• Time in Patent Office: Days
• US Class Current: 701/301
• CPC Class Codes: G08G 1/0104 Measuring and analyzing of parameters relative to traffic conditions
• CPC Class Codes: G08G 1/127 to a central station ; Indicators in a central station

Abstract

A grid-based transmission system for determining relative positions of vehicles in a grid quadrangle of a reference grid, each vehicle having a transmitter and a receiver, comprising determining an absolute position of a vehicle. A reference grid is obtained. A reference point for the reference grid is assigned; and a relative position of the vehicle relative to the reference point is generated. The reference grid is a stored and previously generated reference grid, or is generated based on the absolute position and a transmission range of a transmitter. The vehicle sends a position message containing the relative position; the transmission range; an identity of the vehicle; an identity for all other vehicles that have previously sent a position message received by the vehicle; and the relative position of the all other vehicles.

Claims

1. A grid-based transmission system for determining relative positions of vehicles from their absolute positions in a quadrangle of a reference grid, each vehicle having a transmitter and a receiver, comprising:

a) determining an absolute position of a first vehicle;

b) obtaining the reference grid;

c) assigning a reference point in the reference grid;

d) generating a relative position of the first vehicle relative to the reference point; and

e) the first vehicle transmitting a position message containing the relative position.

2. A system as claimed in claim 1, wherein the reference grid is obtained by retrieving a stored and previously generated reference grid.

3. A system as claimed in claim 1 or, wherein the absolute position is obtained by using a GPS.

4. A system as claimed claim 1, wherein the reference grid has a quadrangle size greater than a maximum transmission range of the transmitter.

5. A system as claimed in claim 4, wherein the reference grid has a quadrangle size at least twice the maximum transmitting range.

6. A system as claimed in claim 1, wherein the reference point is selected from the group consisting of:

an agreed reference point, and the reference point as generated by an agreed methodology.

7. A system as claimed in claim 1, wherein the reference grid is generated based on at least one selected from the group consisting of:

the transmission range of the transmitter of a second vehicle, and the identity of the transmitter of the second vehicle.

8. A system as claimed in claim 7, wherein the maximum transmission range is obtained from a specification of the transmitter.

9. A system as claimed in claim 7, or wherein there is included an additional step:

f) receiving from the second vehicle a position message containing a relative position of the second vehicle, the first vehicle using the relative position of the second vehicle, the maximum transmission range, and the absolute position of the first vehicle to determine the absolute position of the second vehicle.

10. A system as claimed in claim 9, wherein the position message also contains the transmission range of the transmitter of the second vehicle and an identity of the second vehicle, and the reference grid is generated based on at least one selected from the group consisting of:

the transmission range of the transmitter of the second vehicle, and an identity of the transmitter of the second vehicle.

11. A system as claimed in claim 4, wherein the position message also contains at least one of:

the maximum transmission range and an identity of the first vehicle.

12. A system as claimed in claim 11, wherein the position message also contains an identity of all other vehicles that have previously sent a position message that was received by the first vehicle, and the relative position of the all other vehicles, as received by the first vehicle in a predetermined number of previous transmission cycles.

13. A system as claimed in claim 11, wherein the position message is receivable by a second vehicle, the second vehicle using the relative position of the first vehicle, the maximum transmission range, and the absolute position of the second vehicle to determine the absolute position of the first vehicle.

14. A method for determining relative position of vehicles from their absolute positions in a quadrangle of a reference grid, all vehicles having transmitters and receivers, the method comprising:

a) a first vehicle determining its absolute position;

b) the first vehicle obtaining the reference grid;

c) the first vehicle assigning its reference point to the reference grid;

d) the first vehicle generating a relative position of the first vehicle relative to its reference point; and

e) the first vehicle sending a position message containing the relative position.

17. A method as claimed in claim 14, wherein the reference point is selected from the group consisting of an agreed reference point, and a reference point generated by an agreed methodology.

22. A method as claimed in claim 14, wherein the position message contains at least one of:

a maximum transmission range of the transmitter of the first vehicle, and an identity of the transmitter of the second vehicle.

23. A method as claimed in claim 14, wherein the reference point is selected from the group consisting of an agreed reference point, and a reference point generated by an agreed methodology.

24. A method as claimed in claim 22, wherein the reference grid is obtained by being generated based on at least one selected from the group consisting of:

the transmission range of the transmitter of the second vehicle, and the identity of the transmitter of the second vehicle.

25. A method as claimed in claim 14, wherein the absolute position is obtained by using GPS.

26. A method as claimed in claim 22, wherein a size of the grid quadrangle is greater than the maximum transmitting range.

27. A method as claimed in claim 26, wherein the size of the grid quadrangle is at least twice the maximum transmission range.

28. A method as claimed in claim 22, wherein the maximum transmission range is obtained from a specification of the transmitter.

29. A method as claimed in claim 14, wherein the position message also contains an identity of the first vehicle.

32. A method as claimed in claim 14, wherein the position message also contains an identity of all other vehicles that have previously sent a position message that was received by the first vehicle, and the relative position of the all other vehicles;

as received by the first vehicle in a predetermined number of previous transmission cycles.

33. A method as claimed in claim 14, wherein the assigning of the reference point is dynamic.

35. A method as claimed in claim 14, wherein the quadrangle is selected from the group consisting of:

regular quadrangle, irregular quadrangle, rectangle, and square.

36. A method as claimed in claim 35, wherein the quadrangle has at least one side that is not straight.

37. A method as claimed in claim 35, wherein at least one of the size and shape of the quadrangle varies according at least one of the latitude and longitude.

38. A computer usable medium comprising computer program code that is configured to cause a processor to execute one or more functions to perform the method of claim 14.

15. A method for determining absolute positions of vehicles from their relative positions in a quadrangle of a reference grid, all vehicles having a transmitter and a receiver, the method comprising:

a) a second vehicle receiving a relative position message from a first vehicle;

b) the second vehicle obtaining the reference grid;

c) the second vehicle determining its absolute position; and

d) the second vehicle assigning its own reference point in the reference grid, wherein the assigning of the reference point is dynamic.

16. A method as claimed in claim 15, wherein the reference point of the second vehicle is determined by the second vehicle.

18. A method as claimed in claim 15, wherein the first vehicle determines its reference point, the reference point of the first vehicle being the same as the reference point of the second vehicle.

19. A method as claimed in claim 15, wherein the first vehicle determines its reference point, the reference point of the first vehicle being different to the reference point of the second vehicle.

20. A method as claimed in claim 15, wherein the second vehicle generates a relative position of the second vehicle relative to its reference point.

21. A method as claimed in claim 15, wherein the reference grid is obtained by retrieving a stored and previously generated reference grid.

30. A method as claimed in claim 15, wherein the position message also contains a relative position of the first vehicle.

31. A method as claimed in claim 30, wherein the position message also contains an identity of the first vehicle, and at least one of:

the maximum transmission range of the transmitter of the first vehicle, and an identity of the transmitter of the first vehicle, and the reference grid is generated based on at least one of;

the transmission range of the transmitter of the first vehicle, and an identity of the transmitter of the first vehicle.

34. A method as claimed in claim 30, wherein the second vehicle uses the relative position of the first vehicle, the maximum transmission range, and the absolute position of the second vehicle to determine the absolute position of the first vehicle.

39. (canceled)