Method and apparatus for calibration of a distance sensor in a vehicle navigation system
First Claim
1. A method for modifying an odometer reading in a vehicle navigation system to compensate for odometer errors, the method comprising the steps of:
- obtaining a first distance measurement from the odometer, a first vehicle position being associated with the odometer;
obtaining a second distance measurement from at least one other sensor, a second vehicle position being associated with the at least one other sensor;
adjusting a modification factor, the modification factor being for modifying the odometer reading, wherein adjusting the modification factor comprises increasing the modification factor where the first distance measurement is less than the second distance measurement, and decreasing the modification factor where the first distance measurement is greater than the second distance measurement, positive adjustment to the modification factor only occurring where the second vehicle position is ahead of the first vehicle position, and negative adjustment to the modification factor only occurring where the second vehicle position is behind the first vehicle position; and
modifying the odometer reading with the modification factor.
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Accused Products
Abstract
Method and apparatus for modifying an odometer reading in a vehicle navigation system to compensate for odometer errors. A first distance measurement is obtained from the odometer, and a second distance measurement is obtained from at least one other sensor. The difference between the first and second distance measurements is determined and an adjustment amount is generated in response thereto. A modification factor is then adjusted by the adjustment amount, the modification factor being for modifying the odometer reading. The odometer reading is then modified with the modification factor. A method and apparatus for selecting a pulse rate setting in a vehicle navigation system to correspond to a pulse rate associated with the odometer are also described. A first distance measurement is obtained from the odometer and a second distance measurement is obtained from at least one other sensor. The difference between the first and second distance measurements is then determined. The pulse rate setting is changed to correspond to the odometer pulse rate if the difference is greater than a threshold level, and is left unchanged if the difference is less than the threshold level.
110 Citations
8 Claims
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1. A method for modifying an odometer reading in a vehicle navigation system to compensate for odometer errors, the method comprising the steps of:
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obtaining a first distance measurement from the odometer, a first vehicle position being associated with the odometer; obtaining a second distance measurement from at least one other sensor, a second vehicle position being associated with the at least one other sensor; adjusting a modification factor, the modification factor being for modifying the odometer reading, wherein adjusting the modification factor comprises increasing the modification factor where the first distance measurement is less than the second distance measurement, and decreasing the modification factor where the first distance measurement is greater than the second distance measurement, positive adjustment to the modification factor only occurring where the second vehicle position is ahead of the first vehicle position, and negative adjustment to the modification factor only occurring where the second vehicle position is behind the first vehicle position; and modifying the odometer reading with the modification factor. - View Dependent Claims (2, 3, 4, 5)
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6. A vehicle navigation system operable to compensate for odometer errors comprising:
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an odometer for obtaining a first distance measurement, a first vehicle position being associated with the odometer; at least one other sensor for obtaining a second distance measurement, a second vehicle position being associated with the at least one other sensor; a central processing unit for controlling operation of the vehicle navigation system, the central processing unit being operable to adjust a modification factor, the modification factor being for modifying the odometer reading, wherein adjusting the modification factor comprises increasing the modification factor where the first distance measurement is less than the second distance measurement, and decreasing the modification factor where the first distance measurement is greater than the second distance measurement, positive adjustment to the modification factor only occurring where the second vehicle position is ahead of the first vehicle position, and negative adjustment to the modification factor only occurring where the second vehicle position is behind the first vehicle position; and modify the odometer reading with the modification factor.
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7. At least one computer readable medium containing program instructions for modifying an odometer reading in a vehicle navigation system to compensate for odometer errors, the at least one computer readable medium comprising:
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computer readable code for obtaining a first distance measurement from the odometer, a first vehicle position being associated with the odometer; computer readable code for obtaining a second distance measurement from at least one other sensor, a second vehicle position being associated with the at least one other sensor; computer readable code for adjusting a modification factor, the modification factor being for modifying the odometer reading, wherein adjusting the modification factor comprises increasing the modification factor where the first distance measurement is less than the second distance measurement, and decreasing the modification factor where the first distance measurement is greater than the second distance measurement, positive adjustment to the modification factor only occurring where the second vehicle position is ahead of the first vehicle position, and negative adjustment to the modification factor only occurring where the second vehicle position is behind the first vehicle position; and computer readable code for modifying the odometer reading with the modification factor.
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8. At least one computer readable medium containing program instructions for selecting a pulse rate setting to correspond to a pulse rate associated with an odometer in a vehicle navigation system, the at least one computer readable medium comprising:
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computer readable code for determining a difference between a first distance measurement from the odometer and a second distance measurement from at least one other sensor; and computer readable code for changing the pulse rate setting to correspond to the pulse rate if the difference is greater than or equal to a threshold level, and for leaving the pulse rate setting unchanged if the difference is less than the threshold level.
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Specification