Abstract: A method and system are provided for determining a heading angle of a user of a portable electronic device in an indoor environment. In an embodiment, the device collects rotational movement information indicative of rotational movement of the device and determines a first heading angle of the device. The first heading angle is determined by using the downward direction of the device to determine the vertical angular rate in the horizontal plane, and integrating the vertical angular rate to form the first heading angle. The device collects first direction information from a first direction sensor and second direction information from a second direction sensor and uses it determine which of the first and second direction information is an outlier, e.g., inaccurate due to an occurrence of a disturbance. The device then corrects the heading angle by comparing the heading angle to the first and second direction information.

Abstract: A method and system are provided for determining a heading angle of a user of a portable electronic device in an indoor environment. In an embodiment, the device collects rotational movement information indicative of rotational movement of the device and determines a first heading angle of the device. The first heading angle is determined by using the downward direction of the device to determine the vertical angular rate in the horizontal plane, and integrating the vertical angular rate to form the first heading angle. The device collects first direction information from a first direction sensor and second direction information from a second direction sensor and uses it determine which of the first and second direction information is an outlier, e.g., inaccurate due to an occurrence of a disturbance. The device then corrects the heading angle by comparing the heading angle to the first and second direction information.

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.

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.

Abstract: The present invention relates to a system and method for managing energy consumption in a multi-sensor user-carried device during indoor navigation. In an embodiment of the invention, the device calculates a motion mode, a location mode, or an operational mode, each of which is used to modify sensor behavior, e.g., sampling rate, and/or CPU load, e.g., filtering and modeling complexity. The motion mode describes the manner in which the user is moving (standing still, walking, passive transport for example), the location mode describes a feature of the user's location (near level change or intersection for example), and the operational mode describes the manner in which the user is interacting with the device (holding and monitoring, holding and not monitoring, not holding for example).

Abstract: The present invention relates to a system and method for managing energy consumption in a multi-sensor user-carried device during indoor navigation. In an embodiment of the invention, the device calculates a motion mode, a location mode, or an operational mode, each of which is used to modify sensor behavior, e.g., sampling rate, and/or CPU load, e.g., filtering and modeling complexity. The motion mode describes the manner in which the user is moving (standing still, walking, passive transport for example), the location mode describes a feature of the user's location (near level change or intersection for example), and the operational mode describes the manner in which the user is interacting with the device (holding and monitoring, holding and not monitoring, not holding for example).