METHODS AND APPARATUS FOR LOW-COST INERTIAL DEAD-RECKONING USING CONTEXT DETECTION
First Claim
1. A method for determining a user bearing, implemented on a portable device programmed to perform the method comprising:
- determining with a physical sensor of the portable device, a first geometric orientation of the portable device with respect to gravity at a first time;
determining with a magnetic sensor of the portable device, a first sensed magnetic field of the portable device in response to an external magnetic field at the first time;
determining with the magnetic sensor of the portable device, a second sensed magnetic field of the portable device in response to the external magnetic field at the second time; and
determining with the portable device a first change in bearing of the portable device at the second time in response to the first geometric orientation, the first sensed magnetic field, and the second sensed magnetic field.
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Accused Products
Abstract
A method for determining a user bearing, implemented on a portable device programmed to perform the method includes determining with a physical sensor of the portable device, a first geometric orientation of the portable device with respect to gravity at a first time, determining with a magnetic sensor of the portable device, a first sensed magnetic field of the portable device in response to an external magnetic field at the first time, determining with the magnetic sensor of the portable device, a second sensed magnetic field of the portable device in response to the external magnetic field at the second time, and determining with the portable device a bearing of the portable device at the second time in response to the first geometric orientation, the first sensed magnetic field, and the second sensed magnetic field.
23 Citations
19 Claims
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1. A method for determining a user bearing, implemented on a portable device programmed to perform the method comprising:
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determining with a physical sensor of the portable device, a first geometric orientation of the portable device with respect to gravity at a first time; determining with a magnetic sensor of the portable device, a first sensed magnetic field of the portable device in response to an external magnetic field at the first time; determining with the magnetic sensor of the portable device, a second sensed magnetic field of the portable device in response to the external magnetic field at the second time; and determining with the portable device a first change in bearing of the portable device at the second time in response to the first geometric orientation, the first sensed magnetic field, and the second sensed magnetic field. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A portable device for determining a user bearing comprising:
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a physical sensor configured to determine a first geometric orientation of the portable device with respect to gravity at a first time; a magnetic sensor configured to determine a first sensed magnetic field of the portable device in response to an external magnetic field at the first time, wherein the magnetic sensor is configured to determine a second sensed magnetic field of the portable device in response to the external magnetic field at the second time, wherein the first time and the second time are different; and a processor coupled to the physical sensor and the magnetic sensor, wherein the processor is programmed to determine a first change in bearing of the portable device at the second time in response to the first geometric orientation, the first sensed magnetic field, and the second sensed magnetic field. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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Specification