SYSTEMS AND METHODS FOR DYNAMICALLY DETERMINING POSITION

• US 20090267832A1
• Filed: 04/29/2008
• Published: 10/29/2009
• Est. Priority Date: 04/29/2008
• Status: Abandoned Application

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Hymel, James A.
• Application Number:
  US12/111,412
• Publication Number:
  US 20090267832A1
• Time in Patent Office: Days
• US Class Current: 342/357.520
• CPC Class Codes: G01S 19/252 Employing an initial estimate of location in generating assistance data
• CPC Class Codes: G01S 19/31 Acquisition or tracking of other signals for positioning
• CPC Class Codes: G01S 19/35 Constructional details or hardware or software details of the signal processing chain
• CPC Class Codes: G01S 19/46 the supplementary measurement being of a radio-wave signal type

Abstract

A system and method of dynamically determining a position. At least some of the illustrative embodiments are systems comprising a host processor, a sensor configured to send signals indicative of the position of the system to the host processor, an antenna configured to receive signals from GPS satellites, a GPS subsystem coupled to the antenna; wherein the GPS subsystem and host processor are coupled and are configured to make a position determination.

Claims

1. A system comprising:

a host processor;

a sensor coupled to the host processor, the sensor configured to send signals indicative of position of the system to the host processor;

an antenna configured to receive signals from Global Positioning System (GPS) satellites; and

a GPS subsystem coupled to the host processor and the antenna, the GPS subsystem configured to calculate a GPS-based position and send the GPS-based position to the host processor;

the system has a first configuration where the host processor is configured to use the GPS-based position as an actual position of the system, and a second configuration where the GPS-based position is a partial position and the host processor is configured to determine actual position using the GPS-based position and the signals indicative of position from the sensor.

2. The system of claim 1 wherein the sensor further comprises at least one selected from the group consisting of:

an inertial sensor;

an antenna configured to receive signals from a wireless communication antenna;

an antenna configured to receive signals from an Earth-bound positioning system.

3. The system of claim 1 further comprising:

the GPS subsystem is configured to calculate a value indicative of sufficiency of the signals from GPS satellites for actual position determination, and pass the value to the host processor; and

the host processor is configured to configure the system to operate in the first configuration when the value indicates sufficiency, and to configure the system to operate in the second configuration when the value indicates insufficiency.

4. The system of claim 3 wherein when the GPS subsystem calculates the value, the GPS subsystem evaluates at least one selected from the group consisting of:

the number of GPS satellite transmissions received;

the signal-to-noise (SNR) ratio of received GPS satellite transmission; and

dilution of GPS satellite precision.

5. The system of claim 3 wherein when the GPS subsystem calculates the value, the GPS subsystem calculates a dilution of precision, and when the dilution of precision is less than 25 meters, the value indicates sufficiency.

6. The system of claim 3 wherein when the GPS subsystem calculates the value, the GPS subsystem calculates a dilution of precision, and when the dilution of precision is equal to or greater than 25 meters, the value indicates insufficiency.

7. The system of claim 3 wherein when the GPS subsystem calculates the value, the GPS subsystem calculates the value to be a Boolean, and when the value is asserted, the value indicates sufficiency.

8. The system of claim 3 wherein when the GPS subsystem calculates the value, the GPS subsystem calculates the value to be a Boolean, and when the value is not asserted, the value indicates insufficiency.

9. A method comprising:

receiving a plurality of signals, one each from a plurality of Global Positioning System (GPS) satellites;

calculating, by a first processor, a GPS-based position based on the signals and a value indicative of dilution of precision of the position calculation;

passing the GPS-based position and the value to a second processor;

utilizing, by the second processor, the GPS-based position as actual position when the value indicates sufficient precision; and

calculating, by the second processor, actual position based on the GPS-based position and supplementary position data when the value indicates insufficient precision.

10. The method of claim 9 wherein calculating the value indicative of dilution of precision by the first processor further comprises analyzing at least one selected from the group consisting of:

the number of GPS satellite transmissions received;

the signal-to-noise ratio (SNR) of received GPS satellite transmission;

proximity of source of GPS signals received.

11. The method of claim 9 wherein calculating the value indicative of dilution of precision by the first processor further comprises calculating a value indicative of distance the GPS-based position could be in error.

12. The method of claim 9 wherein calculating the value indicative of dilution of precision by the first processor further comprises calculating a Boolean value that, when asserted, indicates sufficient precision, and when not asserted indicated insufficient precision.

13. The method of claim 9 wherein calculating actual position by the second processor further comprises calculating using supplementary position data being at least one selected from the group consisting of:

signals from an inertial sensor;

signals from an antenna configured to receive signals from a wireless communication antenna;

signals an antenna configured to receive signals from an Earth-bound positioning system.

14. A computer-readable media storing a program that, when executed by a processor, causes the processor to:

receive a position indication from a Global Positioning System (GPS) subsystem coupled to the processor;

utilize the position indication as an actual position when a dilution of precision of the position indication is below a first predetermined value; and

calculate an actual position based on the position indication and supplemental position data when the dilution of precision is above a second predetermined value.

15. The computer-readable media of claim 14 wherein when the processor receives, the program further causes the processor to receive a value indicative of dilution of precision of the position indication.

16. The computer-readable media of claim 14 wherein when the processor receives, the program further causes the processor to receive a numerical distance value indicative of dilution of precision of the position indication.

17. The computer-readable media of claim 14 wherein when the processor receives, the program further causes the processor to receive a Boolean value indicative of dilution of precision of the position indication.

18. The computer-readable media of claim 14 wherein when the processor calculates actual position, the program further causes the processor to calculate actual using the position indication and information indicative of location received from at least one selected from the group consisting of:

an inertial sensor, an antenna configured to receive signals from a wireless communication antenna;

an antenna configured to receive signals from an Earth-bound positioning system.

19. A computer-readable media storing a program that, when executed by a processor, causes the processor to:

calculate a position based on a plurality of signals, one each from a plurality of Global Positioning System (GPS) satellites;

determine a value indicative of dilution of precision of the position;

generate a Boolean value that is asserted if the dilution of precisions is less than a first predetermined value, and that is not asserted if the dilution of precision is greater than a second predetermined value; and

send the position and the Boolean value to a host processor.

20. The computer-readable media of claim 19 wherein when the processor determines, the program causes the processor to determine based on at least one selected from the group consisting of:

number of GPS satellite signals received;

the signal-to-noise ratio (SNR) of received GPS satellite signals; and

proximity of the GPS satellites from which signals are received.