Acquisition, collection and processing system for continuous precision tracking of objects

• US 7,667,642 B1
• Filed: 08/13/2006
• Issued: 02/23/2010
• Est. Priority Date: 08/15/2005
• Status: Expired due to Fees

• Current Assignee: Technaumics
• Original Assignee: Technaumics
• Inventors: Frericks, Jeff E., Kelley, Clifford W.
• Primary Examiner(s): Tarcza; Thomas H
• Assistant Examiner(s): Mull; Fred H
• Application Number:
  US11/464,200
• Time in Patent Office: 1,290 Days
• Field of Search: 34235707-35709, 342/357.17, 342/357.02, 348/157
• US Class Current: 342/357.57
• CPC Class Codes: G01S 19/41 Differential correction, e.g. DGPS [differential GPS]

Abstract

A system and method autonomously and precisely track objects moving along a known course. The objects include, for example, racing horses, other racing animals, or racing vehicles. The system and method utilize modern satellite navigation satellite systems, signal processing, radio communications systems and computer processing to acquire and analyze performance data of the moving objects during competitions and during training and practice. The data acquisition is performed continuously at a rate of at least 1 Hz during the competition, training or practice even in the presence of objects which affect the quality of the signals received from the satellite system.

Claims

1. A system for continuous and precise tracking and timing of a plurality of moving objects at a rate of at least 1 Hz over a known course comprising:

a plurality of portable tracking units, each portable tracking unit mounted on and moving with a respective object traveling over a known course, each portable tracking unit comprising;

a global navigation satellite system (GNSS) receiver having a plurality of channels for receiving signals from a plurality of GNSS satellites, each channel comprising a plurality of correlators sufficient to enable the receiver to track a satellite signal when the received power level of the signal is at least as low as −

154 dBm, the receiver continuously generating pseudorange values, delta pseudorange values and signal quality values at a predetermined rate of at least 1 Hz for each satellite signal being received by the receiver; and

a mobile communication link that transmits output signals representing the pseudorange values, delta pseudorange values and signal quality values generated by the receiver;

a reference station located in a known fixed position with respect to the known course, the reference station including a reference GNSS receiver having a plurality of channels for receiving signals from a plurality of GNSS satellites, the reference GNSS receiver generating pseudorange values, delta pseudorange values and signal quality values at a predetermined rate of at least 1 Hz for each satellite signal being received by the reference GNSS receiver, the reference station transmitting output signals representing the pseudorange values, delta pseudorange values and signal quality values generated by the reference GNSS receiver;

a race data processor that receives data from the portable tracking units and from the reference station representing the pseudorange values, delta pseudorange values and signal quality values for each satellite signal received by the receiver in each portable tracking unit and for each satellite signal received by the reference GNSS receiver, the race data processor responsive to the data from each portable tracking unit, the data from the reference GNSS receiver, and signal propagation characteristics of the known course to compute an individual GNSS position and timing solution for each portable tracking unit when the GNSS processing system receives the signal data; and

a race systems controller that provides position and movement data for each portable tracking unit based on the GNSS solution for the tracking unit.

2. The system as defined in claim 1, wherein each channel of the GNSS receiver in each tracking unit includes code tracking and carrier tracking loops.

3. The system as defined in claim 1, wherein each channel of each GNSS receiver in each portable tracking unit has a coherent integration duration of at least 20 milliseconds.

4. The system as defined in claim 1, wherein the plurality of channels comprises at least 12 channels, and wherein the plurality of satellites ranges from 3 satellites to at least 12 satellites.

5. The system as defined in claim 1, wherein the plurality of correlators in each GNSS receiver in each tracking unit comprises at least 30,000 equivalent correlators.

6. The system as defined in claim 1, wherein each portable tracking unit transmits output data at a rate greater than 1200 bits per second per tracking unit.

7. The system as defined in claim 1, wherein the moving objects are horses, and wherein the known course is a racetrack.

8. A method for tracking moving objects in a competition over a known course, comprising:

placing and activating a portable tracking device on each object in the competition, each tracking device positioned on the respective object to receive signals from a plurality of satellites in a global navigation satellite system (GNSS);

collecting GNSS pseudorange and delta pseudorange measurements and satellite almanac and ephemeris data from a reference station in a known, fixed location;

transmitting GNSS pseudorange and delta pseudorange measurements and signal quality information for each satellite being tracked by each portable tracking device to a central location before and during the competition;

transmitting GNSS pseudorange and delta pseudorange measurements and signal quality information for each satellite being tracked by the reference station to the central processing location before and during the competition; and

continually determining an actual position of each object at a rate of at least 1 Hz based on the GNSS pseudorange and delta pseudorange measurements and signal quality information received from the portable tracking unit on the object, based on the GNSS pseudorange and delta pseudorange measurements and signal quality information received from the reference station, and based on signal propagation characteristics of the known course until the conclusion of the competition.

9. The method as defined in claim 8, further comprising analyzing the measurements and signal quality information received from each portable tracking device to determine whether the portable tracking device operating properly.

10. The method as defined in claim 9, further comprising verifying that the portable tracking devices on all objects in a competition are operating properly before starting the competition.

11. The method as defined in claim 8, further comprising displaying the actual position information for each object in real time during the competition.

12. The method as defined in claim 11, further comprising displaying the relative position of each object with respect to other objects in the competition during the competition.

13. The method as defined in claim 11, wherein displaying the actual position information for each object comprises displaying the actual position in a track coordinate system that includes at least a distance along the known course from the beginning of the competition and a distance with respect to a lateral boundary of the known course.

14. The method as defined in claim 11, wherein displaying the actual position information for each object comprises displaying the actual position as a location in a Cartesian coordinate system referenced to a selected origin.

15. The method as defined in claim 11, further comprising deriving and displaying a set of competition metrics for each object in the competition, the set of competition metrics comprising:

identification of the object as a lead object if the object is the lead object or is sharing the lead with another object; and

if the object is not identified as the lead object;

a relative distance of the object behind the lead object in the competition;

a relative speed of the object with respect to the lead object;

displaying an amount of time that the object lags behind the lead object;

a change in the relative distance between the object and the lead object; and

an acceleration of the object with respect to at least the lead object.

16. The method as defined in claim 8, further comprising transferring the actual position information for each object during the competition to a central database for storage.

17. The method as defined in claim 16, wherein the actual position information stored for each object includes:

a start time for the competition;

at least one time relative to the start time when the object passes at least one predetermined location in the known course;

locations of the object at predetermined timing and position intervals during the competition; and

an ending time when the object completes the competition.

18. The method as defined in claim 8, further comprising providing the position or timing information for each object as current information to a plurality of users via a network.

19. The method as defined in claim 8, further comprising analyzing the position information for each object to determine current performance information for the object and comparing the current performance information to historical performance information for the object.

20. The method as defined in claim 19, further comprising simulating the expected performances for the objects in a competition based on previous performance information for the objects determined from the position data collected during other competitions.

21. The method as defined in claim 20, further comprising simulating the performance of at least one object in a previous competition based at least in part on position information collected in the current competition to analyze changes in the performance of the object.

22. The method as defined in claim 8, further comprising providing position data for each object in a competition to a plurality of users during the competition to enable the users to determine the relative positions of the objects at predetermined locations along the known course competition in addition to the relative positions of the objects at the end of the known course.

23. The method as defined in claim 8, further comprising enabling the plurality of users to enter additional wagers during a competition based on relative positions of objects at predetermined locations towards the beginning of the competition.

24. The method as defined in claim 8, further comprising enabling users to wager on the relative positions of the objects when the objects reach predetermined locations in the competition other than the conclusion of the competition.

25. The method as defined in claim 8, further comprising initializing each portable tracking device with current satellite almanac and ephemeris data collected from the reference station to enable each portable tracking device to acquire and track signals from the plurality of GNSS satellites for a predetermined time before the beginning of the competition.

26. A method for acquiring, collecting, processing, and tracking at least one object moving along a predetermined course, comprising:

receiving global navigation satellite system (GNSS) signals from a plurality of satellites in view of a moving receiver mounted on the at least one moving object while the object moves from a starting location to an ending location along the predetermined course;

continually generating GNSS measurement data at a rate of at least 1 Hz in response to the GNSS signals received by the moving receiver;

receiving GNSS signals from a plurality of satellites by a reference receiver in a known location;

continually generating GNSS measurement data at a rate of at least 1 Hz in response to the GNSS signals received by the reference receiver;

transmitting the GNSS data from the moving receiver to a processing station;

transmitting the GNSS data from the reference receiver to the processing station;

processing the GNSS data from the moving receiver to calculate an estimated line of sight distance from the moving receiver to each of the satellites in view of the moving receiver;

computing differential corrections for each of the calculated line of sight distances using the GNSS data from the reference receiver and applying the differential corrections to the calculated line of sight distances to generate a corrected line of sight distance to each of the satellites in view of the moving receiver;

applying an adaptive criteria to each of the corrected line of sight distances to adaptively reject unacceptable measurements and to pass acceptable measurements based in part on known signal propagation characteristics of the predetermined course;

generating an updated line of sight distance from the moving receiver to each satellite for which the respective adaptive criteria pass an acceptable measurement; and

calculating a location of the moving receiver based on the updated line of sight distances.

27. The method as defined in claim 26, wherein:

the GNSS data generated by the moving receiver comprises pseudorange values for each satellite in view of the moving receiver, delta pseudorange values for each satellite in view of the moving receiver, carrier tracking loop status information for each satellite in view of the moving receiver, and tracking quality parameters for each satellite in view of the moving receiver; and

the GNSS data generated by the reference receiver comprises pseudorange values for each satellite in view of the reference receiver, delta pseudorange values for each satellite in view of the reference receiver, carrier tracking loop status information for each satellite in view of the reference receiver, and tracking quality parameters for each satellite in view of the reference receiver.

28. The method as defined in claim 26, wherein applying the adaptive criteria to each corrected line of sight distance to each satellite comprises:

computing an optimal Kalman filter gain responsive to the carrier signal to noise ratio data for the signal from the respective satellite, the estimated elevation to the respective satellite, and carrier loop status information;

computing a state vector that employs estimates of the position, velocity and acceleration of the moving object, a receiver clock offset with respect to the satellite clock, and a clock frequency error for the signal from the respective satellite;

updating a Kalman filter state vector responsive to a current pseudorange value and a current delta pseudorange value from the respective satellite and responsive to geographic aiding data representing the signal propagation characteristics of the predetermined course;

updating a covariance matrix with longitudinal course and lateral course components that adaptively change based on a velocity vector of the moving object and a position of the moving object on the predetermined course;

estimating the position, velocity, and acceleration of the moving object along with virtual timing reference lines to compute a time at which the moving object crosses the timing reference lines;

estimating a position, velocity and acceleration of the moving object and a covariance to project to the next measurement time when the process repeats; and

repeating the foregoing steps for as new data are received periodically.

29. The method as defined in claim 26, further comprising:

generating a satellite clock and ephemeris data by the reference receiver; and

transmitting the satellite clock and ephemeris data to the moving receiver to initialize the moving receiver prior to the object moving from the starting location.

30. A method for acquiring, collecting, processing, and tracking at least one object moving along a predetermined course, comprising:

receiving global navigation satellite system (GNSS) signals from a plurality of satellites in view of a moving receiver mounted on the at least one moving object while the object moves from a starting location to an ending location along the predetermined course;

continually generating GNSS data at a rate of at least 1 Hz in response to the GNSS signals received by the moving receiver;

receiving GNSS signals from a plurality of satellites by a reference receiver in a known location;

continually generating GNSS data at a rate of at least 1 Hz in response to the GNSS signals received by the reference receiver;

processing the GNSS data from the moving receiver to calculate an estimated line of sight distance from the moving receiver to each of the satellites in view of the moving receiver;

computing differential corrections for each of the calculated line of sight distances using the GNSS data from the reference receiver and applying the differential corrections to the calculated line of sight distances to generate a corrected line of sight distance to each of the satellites in view of the moving receiver;

applying an adaptive criteria to each of the corrected line of sight distances to adaptively reject unacceptable measurements and to pass acceptable measurements based in part on known signal propagation characteristics of the predetermined course;

generating an updated line of sight distance from the moving receiver to each satellite for which the respective adaptive criteria pass an acceptable measurement; and

calculating a location of the moving receiver based on the updated line of sight distances.

31. The method as defined in claim 30, wherein:

the GNSS data generated by the moving receiver comprises pseudorange values for each satellite in view of the moving receiver, delta pseudorange values for each satellite in view of the moving receiver, carrier tracking loop status information for each satellite in view of the moving receiver, and tracking quality parameters for each satellite in view of the moving receiver;

the GNSS data generated by the reference receiver comprises pseudorange values for each satellite in view of the reference receiver, delta pseudorange values for each satellite in view of the reference receiver, carrier tracking loop status information for each satellite in view of the reference receiver, and tracking quality parameters for each satellite in view of the reference receiver; and

the signal propagation characteristics of the predetermined course include locations of objects proximate to the predetermine course and parametric information sufficient to calculate multipath, diffractive and refractive effects of the objects on signals from satellites.

32. A method of obtaining and displaying a set of competition metrics for a plurality of animals racing over a known course, comprising:

continually obtaining accurate position data for each of the animals at a rate of at least 1 Hz, the accurate position data based on global network satellite system (GNSS) data received by a respective GNSS receiver mounted on each animal, the GNSS data for each animal adaptively corrected in accordance with the position of each animal on the known course in accordance with satellite signal propagation characteristics affected by known objects proximate to the known course;

generating a set of competition metrics for each animal based on the accurate position date for the animal, the set of competition metrics comprising;

the current numeric position of the animal in the competition;

a distance of the animal laterally with respect to an inner boundary of the predetermined course; and

for any animal that is trailing at least one leading animal, the competition metrics further comprising;

a relative distance of the animal behind the leading animal;

a relative speed of the animal with respect to the leading animal;

an amount of time that the animal lags behind the leading animal; and

an acceleration of the animal with respect to at least the leading animal.

33. The method as defined in claim 32, wherein the competition metrics for each animal further includes:

a start time for the competition;

at least one time relative to the start time when the animal passes at least one predetermined location in the known course;

locations of the animal at predetermined timing intervals during the competition; and

an ending time when the animal completes the competition.