Grid-based transmission system

• US 7,904,242 B2
• Filed: 11/14/2003
• Issued: 03/08/2011
• Est. Priority Date: 04/28/2003
• Status: Expired due to Fees

• Current Assignee: St Electronics Pte Limited (Singapore Technologies Engineering Limited)
• Original Assignee: St Electronics Pte Limited (Singapore Technologies Engineering Limited)
• Inventors: Tzidon, Aviv
• Primary Examiner(s): Tran; Delena
• Application Number:
  US10/554,877
• Publication Number:
  US 20070073483A1
• Time in Patent Office: 2,671 Days
• Field of Search: 701/213, 701/300, 701/215, 342/357.03, 342/357.09, 342/357.1, 342/350, 342/357.2, 34235723-35728, 342/357.34
• US Class Current: 701/213
• 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:

an on-board computer to

a) determine an absolute position of a first vehicle;

b) obtain the reference grid with a quadrangle size greater than a maximum transmitting range of a transmitter for the first vehicle;

c) assign a reference point in the reference grid;

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

e) send a position message containing the relative position and the maximum transmission range of the first vehicle'"'"'s transmitter.

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 wherein the absolute position is obtained by using a Global Positioning System (“

GPS”

).

4. A system as claimed in claim 1, wherein the reference grid has a quadrangle size at least twice the maximum transmitting range.

5. 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.

6. 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.

7. A system as claimed in claim 6, wherein the maximum transmission range is obtained from a specification of the transmitter.

8. A system as claimed in claim 6, wherein the on-board computer further:

f) receives 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.

9. A system as claimed in claim 8, wherein the position message from the second vehicle 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.

10. A system as claimed in claim 1, wherein the position message also contains an identity of the first vehicle.

11. A system as claimed in claim 10, 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.

12. A system as claimed in claim 10, 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.

13. 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 with a quadrangle size greater than a maximum transmitting range of a transmitter for the first vehicle;

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 and the maximum transmission range of the first vehicle'"'"'s transmitter.

14. A method as claimed in claim 13, wherein the reference point is selected from the group consisting of an agreed reference point, and a reference point generated by an agreed methodology.

15. A method as claimed in claim 13, wherein the position message contains an identity of the transmitter of the second vehicle.

16. A method as claimed in claim 15, 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.

17. A method as claimed in claim 15, wherein the maximum transmission range is obtained from a specification of the transmitter.

18. A method as claimed in claim 13, wherein the reference point is selected from the group consisting of an agreed reference point, and a reference point generated by an agreed methodology.

19. A method as claimed in claim 13, wherein the absolute position is obtained by using GPS.

20. A method as claimed in claim 13, wherein the size of the grid quadrangle is at least twice the maximum transmission range.

21. A method as claimed in claim 13, wherein the position message also contains an identity of the first vehicle.

22. A method as claimed in claim 13, 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.

23. A method as claimed in claim 13, wherein the assigning of the reference point is dynamic.

24. A method as claimed in claim 13, wherein the quadrangle is selected from the group consisting of:

regular quadrangle, irregular quadrangle, rectangle, and square.

25. A method as claimed in claim 24, wherein the quadrangle has at least one side that is not straight.

26. A method as claimed in claim 24, wherein at least one of the size and shape of the quadrangle varies according at least one of the latitude and longitude.

27. A computer readable storage medium storing computer program code that is configured to cause a processor to execute one or more functions to perform a method for determining relative positions of vehicles from their absolute positions in a quadrangle of a reference grid comprising:

determining an absolute position of a first vehicle;

obtaining a reference grid with a quadrangle size greater than a maximum transmitting range of a transmitter for the first vehicle;

assigning a reference point to the reference grid;

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

sending a position message containing the relative position and the maximum transmission range of the first vehicle'"'"'s transmitter.