MOBILE OBJECT POSITIONING DEVICE AND NAVIGATION APPARATUS
First Claim
1. A mobile object positioning device comprising:
- a GNSS receiver installed on a mobile object for receiving a signal transmitted from a GNSS satellite and for detecting a current position of the mobile object based on the received signal;
a speed detector for detecting a travel speed of the mobile object;
a direction detector for detecting a travel direction of the mobile object;
a position estimation unit for estimating a current position of the mobile object based on the travel speed of the mobile object detected by the speed detector and travel direction of the mobile object detected by the direction detector;
an error calculation unit for calculating an error of the estimated current position of the mobile object based on a time-wise accumulation of at least one of the error of the travel speed of the mobile object and the error of travel direction of the mobile object;
a control unit for repeating (i) turning off a power supply for the GNSS receiver after correcting the estimated current position of the mobile object estimated by the position estimation unit based on the current position of the mobile object detected by the GNSS receiver, (ii) determining whether the error of the estimated current position of the mobile object, calculation of which is started at a time of turning off of the GNSS receiver, is within a predetermined error tolerance, and (iii) turning on the power supply for the GNSS receiver to correct the estimated current position of the mobile object from the position estimation unit based on the detected current position from the GNSS receiver.
1 Assignment
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Accused Products
Abstract
A GPS receiver is used to receive a signal from GPS satellites, and a current vehicle position is detected based on the received signal. A control unit estimates the current vehicle position based on a travel speed of a vehicle from a vehicle speed sensor and a travel direction of the vehicle from a direction sensor. After correcting the estimated current vehicle position based on the current vehicle position from the GPS receiver, a power supply to the GPS receiver is turned off, and thereafter an error of the estimated current vehicle position is calculated based on an error accumulated for a certain time period regarding the speed and the direction. When the error of the estimated current vehicle position exceeds an error tolerance, the power supply for the GPS receiver is restarted to correct the estimated current vehicle position.
37 Citations
5 Claims
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1. A mobile object positioning device comprising:
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a GNSS receiver installed on a mobile object for receiving a signal transmitted from a GNSS satellite and for detecting a current position of the mobile object based on the received signal; a speed detector for detecting a travel speed of the mobile object; a direction detector for detecting a travel direction of the mobile object; a position estimation unit for estimating a current position of the mobile object based on the travel speed of the mobile object detected by the speed detector and travel direction of the mobile object detected by the direction detector; an error calculation unit for calculating an error of the estimated current position of the mobile object based on a time-wise accumulation of at least one of the error of the travel speed of the mobile object and the error of travel direction of the mobile object; a control unit for repeating (i) turning off a power supply for the GNSS receiver after correcting the estimated current position of the mobile object estimated by the position estimation unit based on the current position of the mobile object detected by the GNSS receiver, (ii) determining whether the error of the estimated current position of the mobile object, calculation of which is started at a time of turning off of the GNSS receiver, is within a predetermined error tolerance, and (iii) turning on the power supply for the GNSS receiver to correct the estimated current position of the mobile object from the position estimation unit based on the detected current position from the GNSS receiver. - View Dependent Claims (2)
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3. A vehicle navigation apparatus comprising:
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a mobile object positioning device installed in a vehicle that serves as a mobile object including a GNSS receiver installed on the mobile object for receiving a signal transmitted from a GNSS satellite and for detecting a current position of the mobile object based on the received signal; a speed detector for detecting a travel speed of the mobile object; a direction detector for detecting a travel direction of the mobile object; a position estimation unit for estimating a current position of the mobile object based on the travel speed of the mobile object detected by the speed detector and travel direction of the mobile object detected by the direction detector; an error calculation unit for calculating an error of the estimated current position of the mobile object based on a time-wise accumulation of at least one of the error of the travel speed of the mobile object and the error of travel direction of the mobile object; a control unit for repeating (i) turning off a power supply for the GNSS receiver after correcting the estimated current position of the mobile object estimated by the position estimation unit based on the current position of the mobile object detected by the GNSS receiver, (ii) determining whether the error of the estimated current position of the mobile object, calculation of which is started at a time of turning off of the GNSS receiver, is within a predetermined error tolerance, and (iii) turning on the power supply for the GNSS receiver to correct the estimated current position of the mobile object from the position estimation unit based on the detected current position from the GNSS receiver, a display unit for displaying an image; a destination setting unit for setting a destination of a travel of the vehicle according to a user operation; a map data storage for storing map data of a map that is used for a route guidance of the vehicle; a route guidance unit for performing the route guidance toward the destination set by the destination setting unit based on the current position of the vehicle from the mobile object positioning device and the map data; a display control unit for displaying the current position of the vehicle during the route guidance toward the destination performed by the route guidance unit, as an image of the map data on the display unit after reading the data from the map data storage, in a manner that superposes the current position of the vehicle on the map. - View Dependent Claims (4, 5)
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Specification