Determining Sensor Orientation in Indoor Navigation
AssigneeSenionLab AB
InventorsDavid Tornqvist, Fredrik Gustafsson, Per Skoglar
Life of this patent
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Abstract
A method and system are provided for improved pedestrian dead reckoning. In an embodiment, the crab angle of a device, i.e., the angle by which the device direction of travel differs from the device orientation, is determined via the processing of measurements from a vector accelerometer. The measured acceleration vector is rotated so that one component is vertical, and the crab angle is then found by determining a horizontal direction having the greatest energy. Correlations between the two horizontal acceleration components and the vertical acceleration component may be computed to determine the user's gait, further improving dead reckoning, e.g., for improving indoor position resolution.
Claims12
A method for determining a crab angle of a portable electronic device, wherein the crab angle is an angle by which the device direction of travel differs from the device orientation, and wherein the device is provided with a vector accelerometer, the method comprising:
- determining an acceleration vector using the vector accelerometer;
- rotating the acceleration vector so that one component is parallel to the vertical;
- and
- computing the device crab angle by finding the direction in the horizontal plane having maximal energy associated therewith.
A portable electronic device that provides pedestrian dead reckoning, the portable electronic device comprising:
- an accelerometer for defining an acceleration vector;
- and
- a processor, the processor being configured to rotate the acceleration vector so that one component is vertical, and compute a crab angle of the device by determining a direction in the horizontal plane with maximal energy, wherein the crab angle is an angle by which the device direction of travel differs from the device orientation.
Dependencies are inferred from the claim text.