An offset correction apparatus for a gyro sensor includes an acceleration sensor, a geomagnetic sensor, a stationary determination unit that determines, by using an output value of the acceleration sensor and an output value of the geomagnetic sensor, whether the gyro sensor is stationary, a difference calculation unit that calculates an offset value of the gyro sensor by using an output value of the gyro sensor, and an offset-value update unit that assumes, as a new offset value, an offset value calculated by the difference calculation unit by using an output value of the gyro sensor determined to be stationary by the stationary determination unit.

A first converter converts an initial attitude in an Euler angle representation into an initial attitude represented by quaternion. An updating unit updates an attitude represented by quaternion by defining the initial attitude represented by quaternion as an initial value, successively substituting output values of the triaxial gyro sensor. A second converter converts the attitude represented by quaternion into an attitude in the Euler angle representation. An angular speed derivation unit derives an angular speed based on a time-dependent change in the attitude in the Euler angle representation. A controller adjusts a period of time for derivation by an initial attitude derivation unit based on a variance value of the output value of the triaxial acceleration sensor or a variance value of the output value of the triaxial gyro sensor, when the speed is lower than a threshold value.

The invention relates to a navigation device comprising a turntable which can be rotated about an axis in at least two different rotary positions, in accordance with a rotary control signal. An inertial measuring unit is arranged on the rotary table which can be rotated with the rotary table. The quality of the measurement data can be determined by the initial measuring unit with the help of an evaluation device. When the determined quality does not reach a predetermined minimum quality, the rotary table rotates in the respective other rotary position.

A calibration scheme measures roll, pitch, and yaw and other speeds and accelerations during a series of vehicle maneuvers. Based on the measurements, the calibration scheme calculates inertial sensor misalignments. The calibration scheme also calculates offsets of the inertial sensors and GPS antennas from a vehicle control point. The calibration scheme can also estimate other calibration parameters, such as minimum vehicle radii and nearest orthogonal orientation. Automated sensor calibration reduces the amount of operator input used when calibrating sensor parameters. Automatic sensor calibration also allows the operator to install an electronic control unit (ECU) in any convenient orientation (roll, pitch and yaw), removing the need for the ECU to be installed in a restrictive orthogonal configuration. The calibration scheme may remove dependencies on a heading filter and steering interfaces by calculating sensor parameters based on raw sensor measurements taken during the vehicle maneuvers.

Disclosed are a correlation coefficient correction method, a correlation coefficient correction apparatus, and a program, capable of improving estimation accuracy of a walking velocity or a stride of a moving object, and an exercise analysis method capable of analyzing a user's exercise with high accuracy. In one aspect, the correlation coefficient correction method includes calculating a reference velocity by using a detection result in a first sensor, calculating characteristic information regarding walking of a moving object by using a detection result in a second sensor mounted on the moving object, and correcting a correlation coefficient in a correlation expression indicating a correlation between the characteristic information and a walking velocity or a stride of the moving object by using the reference velocity.

Examples of systems and methods for locating movable objects such as carts (e.g., shopping carts) are disclosed. Such systems and methods can use dead reckoning techniques to estimate the current position of the movable object. Various techniques for improving accuracy of position estimates are disclosed, including compensation for various error sources involving the use of magnetometer and accelerometer, and using vibration analysis to derive wheel rotation rates. Various techniques utilize characteristics of the operating environment in conjunction with or in lieu of dead reckoning techniques, including characteristic of environment such as ground texture, availability of signals from radio frequency (RF) transmitters including precision fix sources. Navigation techniques can include navigation history and backtracking, motion direction detection for dual swivel casters, use of gyroscopes, determining cart weight, multi-level navigation, multi-level magnetic measurements, use of lighting signatures, use of multiple navigation systems, or hard/soft iron compensation for different cart configurations.

A method and system for providing gyroscope bias self-calibration are described herein. The method comprises powering on one or more gyroscopes; after a predetermined first period of time, and upon determining that the one or more gyroscopes is stationary, measuring input rates of rotation during a predetermined second period of time; and determining an average rate of rotation for each gyroscope channel based upon the measured input rates of rotation during the predetermined second period of time. After determining the average rate of rotation and after the predetermined second period of time, the method further comprises commencing additional measurements by the one or more gyroscopes; determining calibrated gyroscope measurements by subtracting the average rate of rotation from each of the additional measurements; and providing, at the output of the one or more gyroscopes, the calibrated gyroscope measurements.

The inertial unit, IMU, of the drone is mounted on a main circuit board. The IMU (26) includes an internal temperature sensor delivering a chip temperature signal (??.sub.chip). A heating component (36) is mounted on the circuit board near the IMU, and it is provided a thermal guide, incorporated to the circuit board, extending between the heating component and the IMU so as to allow a transfer to the IMU of the heat produced by the heating component. This thermal guide may in particular be a metal planar layer incorporated to the board, in particular a ground plane. A thermal regulation circuit (44-62) receives as an input the chip temperature signal (?.sub.chip) and a set-point temperature signal (??.sub.ref), and delivers a piloting signal (TH_PWM) of the heating component, so as to control the heat supply to the IMU. It is in particular possible to use this fast increase in temperature to perform a complete calibration of the IMU in a few minutes.

System for finding at least one mobile trolley in a locale, the system including at least one communication beacon which has a range covering the locale and which is connected to a computer control unit, and at least one electronic module mounted on the trolley and including a transmission device arranged to transmit position data to the communication beacon, and an inertial motion detection hub that includes a device for detecting linear motion along axes of a detection reference system and a device for detecting angular motion about the axes of the detection reference system and that is arranged to provide position data on the basis of linear motion measurement data and angular motion measurement data, the module being mounted on an element of the trolley such that any movement of the trolley within the locale causes angular movement of the element, the system being arranged to detect when the trolley is stopped when the angular motion measurement data correspond to zero angular motion at one measurement instant and being arranged to set to zero speeds calculated on the basis of the linear motion measurement data corresponding to the same measurement instant.

The invention relates to a navigation device comprising a turntable which can be rotated about an axis in at least two different rotary positions, in accordance with a rotary control signal. An inertial measuring unit is arranged on the rotary table which can be rotated with the rotary table. The quality of the measurement data can be determined by the initial measuring unit with the help of an evaluation device. When the determined quality does not reach a predetermined minimum quality, the rotary table rotates in the respective other rotary position.