Patent application number | Description | Published |
20080266695 | MAGNETIC SENSOR CONTROL DEVICE - A magnetic sensor control device has an input section, a selection section, a calculation section, and a setting section. The input section inputs a plurality of magnetic data each having 3 components sequentially output from a 3-dimensional (3D) magnetic sensor. The selection section selects 4 magnetic data satisfying a predetermined 4-point selection condition from the plurality of the input magnetic data. The calculation section calculates a center point equally distant from 4 points corresponding to the 4 selected magnetic data. The setting section sets 3 components representing the center point as an offset of the magnetic data. | 10-30-2008 |
20100002015 | ORIENTATION-FOLLOWING DISPLAY APPARATUS, ORIENTATION-FOLLOWING DISPLAY METHOD, AND ORIENTATION-FOLLOWING DISPLAY PROGRAM - A display device has a screen that can be positioned in arbitrary postures including a reference posture relative to a space having a reference horizontal orientation. The screen has an xyz orthogonal coordinate system, and the posture of the screen in the space is defined by z-x-z Euler angles α, β, and γ of the xyz orthogonal coordinate system. The screen displays an image to enable recognition of the reference horizontal orientation of the space. A control device derives a specific parameter α+γ as an angle by which the image is rotated so that the reference horizontal orientation recognized from the image follows the reference horizontal orientation of the space when the image is displayed on the screen at arbitrary postures. | 01-07-2010 |
20110010121 | MAGNETIC DATA PROCESSING DEVICE, MAGNETIC DATA PROCESSING METHOD, AND MAGNETIC DATA PROCESSING PROGRAM - In a magnetic data processing device, an accumulating part sequentially acquires magnetic data output from a 3D magnetic sensor to provide a recent statistical population of the magnetic data. A past statistical population storage part stores, as a past statistical population, magnetic data output from the 3D magnetic sensor prior to the magnetic data accumulated as the recent statistical population. A determination part determines whether a distribution of the recent statistical population satisfies a certain condition, and determines whether a mixed statistical population of the past and recent statistical populations satisfies another condition when the recent statistical population does not satisfy the certain condition. An offset derivation part derives an offset of the magnetic data based on the recent statistical population when it satisfies the certain condition and derives an offset of the magnetic data based on the mixed statistical population when it satisfies said another condition. The past statistical population storage part updates the past statistical population using the recent statistical population. | 01-13-2011 |
20110015888 | MAGNETIC DATA PROCESSING DEVICE, MAGNETIC DATA PROCESSING METHOD, AND MAGNETIC DATA PROCESSING PROGRAM - In a magnetic data processing device, an accumulation part repeatedly accumulates a predetermined number of magnetic data to provide a statistical population, while sequentially acquiring magnetic data output from a 3D magnetic sensor. A determination part determines, when the predetermined number of magnetic data is accumulated as a statistical population, whether or not the statistical population is spread two-dimensionally using a first threshold, and determines, when the statistical population is spread two-dimensionally, whether or not an angle between a first plane and a second plane is small to a negligible extent using a second threshold, the first plane including a circle about which the statistical population is concentrated, and the second plane being perpendicular to a line segment connecting a center of the circle and a current offset of the magnetic data. An offset update part updates the current offset based on the statistical population so that the current offset moves in a direction parallel to the first plane as a result of updating, in case that the statistical population is spread two-dimensionally and the angle between the first plane and the second plane is not small to the negligible extent. | 01-20-2011 |
20110015895 | MAGNETIC DATA PROCESSING DEVICE, MAGNETIC DATA PROCESSING METHOD, AND MAGNETIC DATA PROCESSING PROGRAM - In a magnetic data processing device, an accumulating part repeatedly accumulates a predetermined number of magnetic data q | 01-20-2011 |
20110218769 | MAGNETIC DATA PROCESSING DEVICE, METHOD, AND PROGRAM - In a magnetic data processing device, an input part sequentially receives magnetic data q | 09-08-2011 |
20120245877 | GEOMAGNETIC FIELD MEASUREMENT DEVICE, OFFSET DETERMINATION METHOD, AND COMPUTER READABLE RECORDING MEDIUM THEREFOR - A geomagnetic field measurement device has a three-dimensional magnetic sensor and a storage device that stores plural pieces of magnetic data sequentially output from the three-dimensional magnetic sensor. The geomagnetic field measurement device calculates, based on the pieces of magnetic data, a distortion estimation value indicating a degree of difference in shape between a three-dimensional figure defined so that the plural sets of coordinates indicated respectively by the plural pieces of magnetic data are distributed adjacent to a surface thereof and a spherical surface, and determines whether there is distortion in the shape of the three-dimensional figure based on the distortion estimation value, to update an offset for correcting each of the plural pieces of the magnetic data in a case in which it is determined that there is no distortion. | 09-27-2012 |
20130060470 | GEOMAGNETISM MEASUREMENT APPARATUS - In a geomagnetism measurement apparatus, a magnetic sensor detects magnetic data, and a storage unit stores the magnetic data sequentially output from the magnetic sensor. An ellipsoid generation unit calculates each ellipsoidal central point of first, second and third ellipsoids each of which has in the vicinity thereof a plurality of the magnetic data stored in the storage unit. An ellipsoidal central point decision unit decides whether or not a distance between respective ellipsoidal central points is equal to or less than a threshold value. A correction value generation unit calculates an ellipsoidal correction matrix for converting coordinates on an ellipsoid into coordinates on a sphere based on a coefficient matrix representing a shape of one of the first, second and third ellipsoids according to the decision result. | 03-07-2013 |
20130073253 | STATE ESTIMATION APPARATUS AND OFFSET UPDATE METHOD - A state estimation apparatus has a plurality of sensors including a three-dimensional magnetic sensor for detecting magnetic components. A Kalman filter is used to update a state vector based on an observation residual. The state vector has components representing a plurality of state variables which include a state variable for estimating an offset of the magnetic data. A central point calculation unit assumes that coordinates indicated by a predetermined number of the magnetic data probabilistically distribute in the vicinity of a spherical surface, and calculates a central point of the spherical surface. The Kalman filter updates the state variable for estimating an offset of the magnetic data using the central point of the spherical surface. | 03-21-2013 |
20130110451 | STATE ESTIMATION APPARATUS | 05-02-2013 |
20140122015 | ATTITUDE ESTIMATION METHOD AND APPARATUS - From a first estimation value of attitude of equipment at a first time, a second estimation value of attitude of the equipment at a second time is derived. For this purpose, a predicted value of the attitude at the second time is generated by applying the first estimation value to a state transition model indicating transition of attitude of the equipment. Then, a difference between the predicted value of the attitude and a true value of the attitude of the equipment is calculated based on data outputted from a sensor in the equipment to thereby generate an estimated attitude error between the predicted attitude and true attitude of the equipment. Further, a specific attitude component is extracted from a plurality of attitude components of the estimated attitude error. Lastly, the second estimation value is calculated based on the predicted value of the attitude and the specific attitude component. | 05-01-2014 |
20140214364 | METHOD OF ESTIMATING OFFSET OF MAGNETIC SENSOR - An offset estimation method calculates attitude data representing an attitude variation of equipment from a reference attitude thereof based on angular velocity data that is outputted from an angular velocity sensor and that represents angular velocity of the equipment. The offset estimation method further calculates an estimation value of the offset minimizing an error between first variable vectors associated to the attitude data and second variable vectors associated to magnetic data that are successively outputted from a magnetic sensor. The first variable vector is obtained by changing a reference variable vector in accordance with the attitude variation represented by the attitude data, the reference variable vector representing geomagnetism when the equipment is placed in the reference attitude, and the second variable vector is obtained by subtracting the estimation value of the offset from the magnetic data. | 07-31-2014 |