Vehicle navigation system and method using GPS velocities
DCFirst Claim
1. An improved navigation system having a GPS receiver which provides GPS velocity information, said navigation system calculating a displacement based upon said GPS velocity information over a time interval, said vehicle navigation system adding said displacement to a previous position to obtain a current position.
13 Assignments
Litigations
1 Petition
Reexaminations
Accused Products
Abstract
The improved vehicle navigation system can take advantage of the recent availability of low cost micro-machined and piezoelectric sensors, and partially overcomes the low dynamics and line of sight limitations of GPS receivers without resorting to the hard wired approach described above. The low cost sensors introduce system level errors due to their inherent DC offset and drift rates. The improved vehicle navigation system minimizes both the sensor induced errors and GPS low dynamic limitations by using a zero motion detection system as a self contained (within the navigation system), vehicle independent device.
287 Citations
28 Claims
- 1. An improved navigation system having a GPS receiver which provides GPS velocity information, said navigation system calculating a displacement based upon said GPS velocity information over a time interval, said vehicle navigation system adding said displacement to a previous position to obtain a current position.
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10. An improved navigation system comprising:
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a GPS receiver which provides GPS velocity information, said navigation system using GPS velocity information to propagate a previous position to a current position, said system determines east and north displacements by integrating said GPS velocity information and applies said east and north displacements to said previous position to obtain said current position; and sensors providing information used to propagate vehicle position if said GPS velocity information is not available, said navigation system determines calibration information from said GPS velocity information to calibrate said sensors. - View Dependent Claims (11, 12, 13)
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14. An improved navigation system comprising:
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a GPS receiver which provides GPS velocity information, said navigation system using GPS velocity information to propagate a previous position to a current position, said system determines east and north displacements from said GPS velocity information and applies said east and north displacements to said previous position to obtain said current position; and an orthogonal axes accelerometer providing longitudinal and lateral acceleration information, said vehicle navigation system determines longitudinal and lateral calibration information from said GPS velocity information to calibrate said orthogonal axes accelerometer; and a zero motion detection system which provides a zero motion signal upon detecting a zero motion state to resolve ambiguity of low velocity GPS information. - View Dependent Claims (15, 16, 23)
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17. A method of determining a current position from a previous position including the steps of:
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providing GPS velocity information; calculating a displacement based upon said GPS velocity information over a time interval; and using said displacement to propagate a previous position to a current position. - View Dependent Claims (18, 19, 20, 21)
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22. A method of determining a current position from a previous vehicle position including the steps of:
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providing GPS velocity information; determining east and north displacements by integrating said GPS velocity information over a time interval; applying said east and north displacements to said previous position to obtain said current position; providing longitudinal and lateral acceleration information by an orthogonal axes accelerometer; determining longitudinal and lateral calibration information from said GPS velocity information; and calibrating said orthogonal axes accelerometer with said calibration information. - View Dependent Claims (24, 25)
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26. A method for dead reckoning position utilizing GPS velocity including the steps of:
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a) determining a first position; b) determining a first pseudorange measurement with respect to each of a plurality of satellites; c) determining a second pseudorange measurement with respect to each of said plurality of satellites after said step b); d) calculating a delta range with respect to each of said plurality of satellites, each based upon one of said first pseudorange measurements and one of said second pseudorange measurements; e) calculating GPS velocity based upon said plurality of delta ranges; f) calculating a displacement based upon said GPS velocity over a time interval; g) adding said displacement to said first position to obtain a second position. - View Dependent Claims (27, 28)
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Specification