Applying a correct factor derivative method for determining an orientation of a portable electronic device based on sense gravitation component linear accelerate filter data obtained
First Claim
1. A method for determining an orientation of a portable electronic device, comprising:
- sensing a rotational rate of the device using a first rotational sensor;
sensing a total acceleration including a gravitational component and linear acceleration component of the device using a first inertial sensor;
filtering data obtained by the first inertial sensor using a variable low pass filter which filters the data by an amount that depends at least in part on the sensed rotational rate of the device;
deriving an orientation of the device at successive periods of time based in part on the rotational rate sensed during each period of time; and
applying a correction factor to the derived orientation of the device based at least in part on the sensed gravitational component and the linear acceleration component of the filtered data obtained by the first inertial sensor only subsequent to satisfaction of a specified condition, the condition being satisfied when the first inertial sensor senses a value for the total acceleration that is equal to the gravitational component within a predefined threshold to obtain a corrected orientation of the device at a subset of the successive periods of time,wherein applying the correction factor includes adjusting the derived orientation in response to a feedback control signal from the first inertial sensor to obtain the corrected orientation of the device.
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Accused Products
Abstract
A method for determining an orientation of a portable or mobile electronic device includes determining an orientation of the device using at least a first inertial motion sensor (e.g., a gyroscope) with which the portable electronic device is equipped. A correction factor is provided to the orientation of the electronic device using a feedback control signal based on motion data obtained from at least a second inertial motion sensor (e.g. an accelerometer) to reduce drift in motion data obtained from the first inertial sensor. Responsive to a loss of valid motion data from the first inertial motion sensor, a rate at which the correction factor is provided to the orientation of the portable electronic device is increased.
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Citations
19 Claims
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1. A method for determining an orientation of a portable electronic device, comprising:
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sensing a rotational rate of the device using a first rotational sensor; sensing a total acceleration including a gravitational component and linear acceleration component of the device using a first inertial sensor; filtering data obtained by the first inertial sensor using a variable low pass filter which filters the data by an amount that depends at least in part on the sensed rotational rate of the device; deriving an orientation of the device at successive periods of time based in part on the rotational rate sensed during each period of time; and applying a correction factor to the derived orientation of the device based at least in part on the sensed gravitational component and the linear acceleration component of the filtered data obtained by the first inertial sensor only subsequent to satisfaction of a specified condition, the condition being satisfied when the first inertial sensor senses a value for the total acceleration that is equal to the gravitational component within a predefined threshold to obtain a corrected orientation of the device at a subset of the successive periods of time, wherein applying the correction factor includes adjusting the derived orientation in response to a feedback control signal from the first inertial sensor to obtain the corrected orientation of the device. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A portable electronic device, comprising:
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at least first and second inertial sensors for sensing motion of the device, the first inertial sensor providing motion data of a first type and the second inertial sensor providing motion data of a second type different from the first type; one or more processors for executing computer-executable instructions; and one or more computer-readable storage media for storing the computer-executable instructions, the instructions when executed by the one more processors implementing processing logic that, based on motion data derived from the first inertial sensor in response to physical movement of the electronic device, tracks an orientation of the device, said tracked orientation having an error arising in measuring the device orientation with the first inertial sensor, the processing logic periodically reducing the error using a feedback control mechanism in which a feedback control signal of a proportional-integral-derivative (PID) control process uses additional motion data of the second type obtained from the second inertial sensor, wherein, if said processing logic determines that rotational motion data obtained from the first inertial sensor is invalid or unavailable while tracking the orientation of the device, the processing logic suppressing an integral function and causing a proportional function of the PID control process to increase its response rate until the rotational motion data is again available and valid. - View Dependent Claims (11, 12, 13, 14, 15, 16)
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17. A mobile electronic device, comprising:
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at least first and second inertial sensors for sensing motion of the device; one or more processors for executing computer-executable instructions which, when executed by the one or more processors, perform a method comprising the steps of; determining an orientation of the mobile electronic device using at least the first inertial motion sensor with which the mobile electronic device is equipped; providing a correction factor to the orientation of the mobile electronic device using a feedback control signal based on motion data obtained from the second inertial motion sensor to reduce drift in motion data obtained from the first inertial sensor, the correction factor only being provided subsequent to satisfaction of a specified condition, the specified condition being satisfied when the second inertial sensor does not sense any linear acceleration of the mobile electronic device such that the second inertial sensor only senses a value for total acceleration that is equal to a gravitational component within a predefined threshold; responsive to a loss of valid motion data from the first inertial motion sensor, increasing a rate at which the correction factor is provided to the orientation of the mobile electronic device. - View Dependent Claims (18, 19)
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Specification