Odometer assisted GPS navigation method
First Claim
1. An odometer assisted Global Positioning System (GPS) method for vehicle positioning, said vehicle including an odometer, a processor and a GPS receiver, said method comprising the steps of:
- finding a last known position of the vehicle;
finding by the GPS receiver, for each satellite of the GPS in line of sight with the vehicle, a measured Doppler and a measured pseudo range;
determining by the processor from the odometer a speed of the vehicle;
determining by the processor a Doppler compensation to the measured Doppler for each satellite of said GPS in line of sight with the vehicle;
combining by the processor the speed of the vehicle with the Doppler compensation to the measured Doppler to produce a new heading of the vehicle;
the step of combining by the processor the speed of the vehicle with the Doppler compensation includes the steps of;
propagating a GPS heading error variance for expected dynamics of the vehicle;
computing actual GPS heading error variance using the speed and the line of sight of each satellite with thedetermining whether the actual GPS heading error variances are excessive; and
combining by the processor the last known position of the vehicle with the new heading and with the Doppler compensation to the measured Doppler and the measured pseudo range to provide a new position of the vehicle.
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Accused Products
Abstract
An odometer assisted global positioning system (GPS) method operates in a vehicle to indicate the position of the vehicle. The vehicle has an odometer, a processor, and a GPS receiver. The method knows the last position of the vehicle and finds a measured Doppler and a measured pseudo range for each satellite of the GPS which is in line of sight with the vehicle. The processor determines the Doppler compensation to the measured Doppler. The processor combines the speed of the vehicle with the Doppler compensation to the measured Doppler in order to produce a new heading of the vehicle. The processor combines the last known position of the vehicle with the new heading and with the Doppler compensation and the measured pseudo range to provide a new position of the vehicle.
44 Citations
15 Claims
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1. An odometer assisted Global Positioning System (GPS) method for vehicle positioning, said vehicle including an odometer, a processor and a GPS receiver, said method comprising the steps of:
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finding a last known position of the vehicle; finding by the GPS receiver, for each satellite of the GPS in line of sight with the vehicle, a measured Doppler and a measured pseudo range; determining by the processor from the odometer a speed of the vehicle; determining by the processor a Doppler compensation to the measured Doppler for each satellite of said GPS in line of sight with the vehicle; combining by the processor the speed of the vehicle with the Doppler compensation to the measured Doppler to produce a new heading of the vehicle; the step of combining by the processor the speed of the vehicle with the Doppler compensation includes the steps of; propagating a GPS heading error variance for expected dynamics of the vehicle; computing actual GPS heading error variance using the speed and the line of sight of each satellite with the determining whether the actual GPS heading error variances are excessive; and combining by the processor the last known position of the vehicle with the new heading and with the Doppler compensation to the measured Doppler and the measured pseudo range to provide a new position of the vehicle. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. An odometer assisted Global Positioning System (GPS) method for vehicle positioning, said vehicle including an odometer, a processor and a GPS receiver, said method comprising the steps of:
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finding by the GPS receiver, for each satellite of the GPS in line of sight with the vehicle, a measured Doppler and a measured pseudo range; determining by the processor from the odometer a speed of the vehicle; determining by the processor a Doppler compensation to the measured Doppler for each satellite of said GPS in line of sight with the vehicle; combining by the processor the speed of the vehicle with the Doppler compensation to the measured Doppler to produce a heading of the vehicle; the step of combining by the processor the speed of the vehicle with the Doppler compensation includes the steps of; propagating a GPS heading error variance for expected dynamics of the vehicle; computing actual GPS heading error variance using the speed and the line of sight of each satellite with the vehicle; determining whether the actual GPS heading error variances are excessive; and combining by the processor the heading with the Doppler compensation to the measured Doppler and with the measured pseudo range to provide a position of the vehicle.
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Specification