Precise universal time for vehicles
First Claim
1. A method of providing a system timing signal sequence for each of a plurality of N vehicles, numbered consecutively i=1,2, . . ., N(N≧
- 2) that move within a selected geographic region and that communicate with one or more base stations, located within or adjacent to the selected region, by radiowaves, the method comprising the steps of;
providing a sequence of M non-overlapping time slots (M≧
2) of approximately equal length that include substantially all times in a selected time interval;
allocating an ith group of these time slots, numbered consecutively i=1,2, . . . , N, to communication by vehicle number i with a base station, where no two groups of time slots have any time slots in common;
providing each vehicle with a sequence of SPS signals and SPS timing signals and with a SPS signal transceiver/processor that receives and processes these SPS signals and SPS timing signals, to determine the present location of that vehicle and the time of determination of vehicle location;
transmitting from one or more base stations a sequence of base station timing signals that are received by each vehicle;
providing each vehicle with a timing signal choice means for receiving the SPS timing signal sequence and the base station timing signal sequence, for determining which of these sequences is both presently available and presently most accurate, and for using the available and most accurate timing signal sequence to provide that vehicle with a vehicle timing signal sequence and to determine the allocated time slots for that vehicle, based upon the most accurate timing sequence available; and
transmitting selected vehicle operating data, including present vehicle location, from each vehicle to one or more base stations during each time slot that is allocated to that vehicle.
2 Assignments
0 Petitions
Accused Products
Abstract
Method and apparatus for providing precise universal time coordination or synchronization for each of a plurality of N vehicles, numbered consecutively i=1, 2, . . ., N (N≧2) that move within a selected geographic region and that communicate by radiowaves with one or more base stations located within or adjacent to the selected region. Each vehicle is provided with a sequence of Satellite Positioning System (SPS) signals, with a sequence of SPS timing signals, and with a SPS signal transceiver/processor that receives the SPS signals and SPS timing signals and determines the present location of the vehicle and the time the vehicle location determination is made. One or more base stations broadcast a sequence of base station timing signals that are received by each vehicle. A timing signal choice means on each vehicle receives the SPS timing signals sequence and the base station timing signals sequence and chooses the timing signal sequence that is both presently available and presently the most accurate. A sequence of nonoverlapping time slots is determined that includes substantially all times within a selected time interval. An ith group of these time slots is allocated to vehicle number i, with no two of these groups having one or more time slots in common. An on-board clock provides back-up time if SPS and base station timing signals are both unavailable; on-board clock time is continually corrected by SPS time or base station time, if available. The chosen sequence of timing signals for vehicle number i is then used to determine the times within the ith group of time slots during which that vehicle will transmit selected vehicle operating data, including present vehicle position, to one or more base stations. At any time, the chosen sequence of timing signals is accurate to within a range as low as 2-7 milliseconds. The Satellite Positioning System may be a Global Positioning System, a Global Orbiting Navigational System, or any other satellite-based system that provides accurate information on position and/or time of observation.
218 Citations
25 Claims
-
1. A method of providing a system timing signal sequence for each of a plurality of N vehicles, numbered consecutively i=1,2, . . ., N(N≧
- 2) that move within a selected geographic region and that communicate with one or more base stations, located within or adjacent to the selected region, by radiowaves, the method comprising the steps of;
providing a sequence of M non-overlapping time slots (M≧
2) of approximately equal length that include substantially all times in a selected time interval;allocating an ith group of these time slots, numbered consecutively i=1,2, . . . , N, to communication by vehicle number i with a base station, where no two groups of time slots have any time slots in common; providing each vehicle with a sequence of SPS signals and SPS timing signals and with a SPS signal transceiver/processor that receives and processes these SPS signals and SPS timing signals, to determine the present location of that vehicle and the time of determination of vehicle location; transmitting from one or more base stations a sequence of base station timing signals that are received by each vehicle; providing each vehicle with a timing signal choice means for receiving the SPS timing signal sequence and the base station timing signal sequence, for determining which of these sequences is both presently available and presently most accurate, and for using the available and most accurate timing signal sequence to provide that vehicle with a vehicle timing signal sequence and to determine the allocated time slots for that vehicle, based upon the most accurate timing sequence available; and transmitting selected vehicle operating data, including present vehicle location, from each vehicle to one or more base stations during each time slot that is allocated to that vehicle. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
- 2) that move within a selected geographic region and that communicate with one or more base stations, located within or adjacent to the selected region, by radiowaves, the method comprising the steps of;
-
23. A method of providing a system timing signal sequence, with a timing inaccuracy no larger than 2 msec, for each of a plurality of N vehicles, numbered consecutively i=1, 2, . . . , N (N≧
- 2) that move within a selected geographic region and that communicate with one or more base stations, located within or adjacent to the selected region, by radiowaves, the method comprising the steps of;
providing a sequence of M non-overlapping time slots (M≧
2) of approximately equal length that include substantially all times in a selected time interval;allocating an ith group of these time slots, numbered consecutively i=1, 2, . . . , N, to communication by vehicle number i with a base station, where no two groups of time slots have any time slots in common; providing each vehicle with first and second independent sequences of timing signals that each provide acceptably accurate timing on each vehicle, where the first sequence is a sequence of SPS signals and SPS timing signals; providing each vehicle with a SPS signal transceiver/processor that receives and processes these SPS signals and SPS timing signals, to determine the present location of that vehicle and the time of determination of vehicle location; providing each vehicle with a timing signal choice means that receives first and second sequences of timing signals, determines which of these sequences is both presently available and presently most accurate, and uses the available and most accurate timing signal sequence to provide that vehicle with a vehicle timing signal sequence and to determine the allocated time slots for that vehicle, based upon the most accurate timing sequence available; and transmitting selected vehicle operating data, including present vehicle location, from each vehicle to one or more base stations during each time slot that is allocated to that vehicle. - View Dependent Claims (24, 25)
- 2) that move within a selected geographic region and that communicate with one or more base stations, located within or adjacent to the selected region, by radiowaves, the method comprising the steps of;
Specification
-
- Resources
-
Current AssigneeTrimble Navigation Limited (Trimble Inc.)
-
Original AssigneeTrimble Navigation Limited (Trimble Inc.)
-
InventorsDesai, Simon, MacKnight, James G.
-
Primary Examiner(s)Issing, Gregory C.
-
Application NumberUS08/011,988Time in Patent Office490 DaysField of Search342/352, 342/356, 342/357, 342/387, 342/457, 368/47, 368/46, 368/14US Class Current342/387CPC Class CodesG01S 19/23 Testing, monitoring, correc...G04R 20/02 the radio signal being sent...G04R 20/14 the radio signal being a te...
