STATE ESTIMATION APPARATUS
First Claim
1. A state estimation apparatus mounted in an instrument comprising a part generating a magnetic field, the state estimation apparatus comprising:
- a three-dimensional magnetic sensor that detects magnetic components in three directions perpendicular to each other and sequentially outputs magnetic data as three-dimensional vector data expressed in a three axis coordinate system;
a three-dimensional acceleration sensor that detects acceleration at three axes perpendicular to each other and sequentially outputs acceleration data as three-dimensional vector data expressed in a three axis coordinate system;
a stability decision module that decides whether motion of the instrument is stable or not; and
a Kalman filter operation module that sets an initial vector to a state vector of Kalman filter as an initial value thereof in case that the stability decision module decides that the motion of the instrument is stable, and then updates the state vector of Kalman filter using an observed value vector having outputs of a plurality of sensors being mounted in the instrument and including the three-dimensional magnetic sensor and the three-dimensional acceleration sensor, the initial vector having as components thereof an estimated value of an offset representing the magnetic field generated by the part of the instrument and a vector estimating a posture of the instrument.
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Accused Products
Abstract
A state estimation apparatus is mounted in a portable instrument having a part generating a magnetic field. The state estimation apparatus is provided with a magnetic sensor and an acceleration sensor. A stability decision module decides whether motion of the portable instrument is stable or not. A Kalman filter operation module sets an initial vector to a state vector of Kalman filter as an initial value thereof in case that the stability decision module decides that the motion of the portable instrument is stable, and then updates the state vector using an observed value vector having outputs the magnetic sensor and the acceleration sensor, the initial vector having as components thereof an estimated value of an offset representing the magnetic field generated by the part of the instrument and a vector estimating a posture of the portable instrument.
8 Citations
10 Claims
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1. A state estimation apparatus mounted in an instrument comprising a part generating a magnetic field, the state estimation apparatus comprising:
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a three-dimensional magnetic sensor that detects magnetic components in three directions perpendicular to each other and sequentially outputs magnetic data as three-dimensional vector data expressed in a three axis coordinate system; a three-dimensional acceleration sensor that detects acceleration at three axes perpendicular to each other and sequentially outputs acceleration data as three-dimensional vector data expressed in a three axis coordinate system; a stability decision module that decides whether motion of the instrument is stable or not; and a Kalman filter operation module that sets an initial vector to a state vector of Kalman filter as an initial value thereof in case that the stability decision module decides that the motion of the instrument is stable, and then updates the state vector of Kalman filter using an observed value vector having outputs of a plurality of sensors being mounted in the instrument and including the three-dimensional magnetic sensor and the three-dimensional acceleration sensor, the initial vector having as components thereof an estimated value of an offset representing the magnetic field generated by the part of the instrument and a vector estimating a posture of the instrument. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A control method of a state estimation apparatus mounted in an instrument comprising a part generating a magnetic field, the state estimation apparatus including a three-dimensional magnetic sensor that detects magnetic components in three directions perpendicular to each other and sequentially outputs magnetic data as three-dimensional vector data expressed in a three axis coordinate system, and a three-dimensional acceleration sensor that detects acceleration at three axes perpendicular to each other and sequentially outputs acceleration data as three-dimensional vector data expressed in a three axis coordinate system, the control method comprising:
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a stability decision step of deciding whether motion of the instrument is stable or not; and a Kalman filter operation step of setting an initial vector to a state vector of Kalman filter as an initial value thereof in case that the stability decision step decides that the motion of the instrument is stable, and then updating the state vector of Kalman filter using an observed value vector having outputs of a plurality of sensors being mounted in the instrument and including the three-dimensional magnetic sensor and the three-dimensional acceleration sensor, the initial vector having as components thereof an estimated value of an offset representing the magnetic field generated by the part of the instrument and a vector estimating a posture of the instrument.
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Specification