In some implementations, a sensing device associated with less than a 360 degree measurement range may obtain a set of signal values. The sensing device may be configured to sense a magnetic field present at the sensing device and collect sensor data based on the magnetic field. The set of signal values may be included in the sensor data collected by the sensing device and may correspond to one or more components of the magnetic field present at the sensing device. The sensing device may determine, based on the set of signal values, a set of calibration points and a set of angular positions. The sensing device may calculate a set of calibration parameters based on the set of calibration points and the set of angular positions. The sensing device may utilize the set of calibration parameters to perform one or more safety checks.

The present invention relates to a sensor suite comprising at least one sensor. More particularly, the present invention relates to a sensor suite for measuring absolute and/or relative position, location and orientation of an object on or in which the sensor suite is employed. The present invention further relates to improved, novel sensor types for use in the sensor suite. More particularly, the present invention relates to an improved, novel magnetometer that is self-calibrating and scalable. Still more particularly, the present invention relates to such a magnetometer that is miniaturized. Further embodiments of the present invention relate to systems and methods for providing location and guidance, and more particularly for providing location and guidance in environments where global position systems (GPS) are unavailable or unreliable (GPS denied and/or degraded environments).

A fitness tracking system includes a shoe, a magnetometer, and a controller. The magnetometer is mounted on the shoe and is configured to generate three-axis direction data in response to movement of the shoe during a predetermined time period. The controller is operably connected to the magnetometer and is configured to generate two-axis calibrated direction data based on the three-axis direction data after the predetermined time period. The two-axis calibrated direction data corresponds to an orientation of the shoe during the predetermined time period.

The present invention relates to a hall electromotive force signal detection circuit and a current sensor thereof each of which is able to achieve excellent wide-band characteristics and fast response as well as high accuracy. A difference calculation circuit samples a component synchronous with a chopper clock generated by a chopper clock generation circuit, out of an output voltage signal of a signal amplifier circuit, at a timing obtained from the chopper clock, so as to detect the component. An integrating circuit integrates an output from the difference calculation circuit in the time domain. An output voltage signal from the integrating circuit is fed back to a signal amplifier circuit via a third transconductance element.

A system for calibrating alignment of two or more types of magnetic sensors in a virtual reality (VR) or augmented reality (AR) display device. The system can include a controller, a waveform generator, a magnetic field generating unit, and an electrical driver. The controller can cause the waveform generator to generate a first calibration waveform to calibrate a first type of magnetic sensor in the display device, and to generate a second calibration waveform to calibrate a second type of magnetic sensor in the display device.

A method for measuring the intensity of an external magnetic field by using a magnetic memory point including a storage layer having a magnetisation switchable between two magnetisation directions substantially perpendicular to the plane of the layer; a reference layer having a fixed magnetisation perpendicular to the plane of the layer; and a tunnel barrier layer separating the storage layer and the reference layer; the method including successively applying a plurality of currents or voltages of different amplitudes to the memory point until switching of the magnetisation direction of the storage layer takes place to determine a minimum switching current value of the magnetisation direction of the storage layer or a minimum switching voltage value of the magnetisation direction of the storage layer, and determining the intensity of the external magnetic field to be measured from the minimum switching current value or the minimum switching voltage value.

An electronic device includes a magnetometer that outputs magnetometer sensor signals and a gyroscope that outputs gyroscope sensor signals. The electronic device includes a magnetometer calibration module that calibrates the magnetometer utilizing the gyroscope sensor signals. The electronic device generates a first magnetometer calibration parameter based on a Kalman filter process. The electronic device generates a second magnetometer calibration parameter based on a least squares estimation process.

A method of calibrating a magnetometer may include; obtaining at least four measurement values using the magnetometer, calculating a center and a radius of a sphere in accordance with the measurement values, wherein the center and the radius of the sphere correspond to an internal magnetic field associated with an electronic device including the magnetometer, and calibrating an output of the magnetometer in accordance with the center of the sphere.

Provided is a magnetic field measuring apparatus for: acquiring the measurement data measured by a magnetic sensor array that is configured by arraying the plurality of magnetic sensor cells to form a surface covering at least a part of a target object to be measured; performing signal separation on a magnetic field spatial distribution indicated by the measurement data based on a position and magnetic sensitivity of each magnetic sensor; generating a calibration magnetic field at a position on a straight line that can be drawn without crossing the plurality of magnetic sensor cells from the measurement space outside the measurement space; and calibrating a sensor error for the magnetic sensor based on a separation error in a case where signal separation has been performed on a spatial distribution of the calibration magnetic field.

Vehicle position is determined using magnetic field measurements within an indoor environment. Magnetic field measurements and sensor information are obtained from the vehicle and magnetic map information is obtained for the indoor environment. Parameters of vehicle motion are derived from the sensor information. The magnetic field measurements are processed to mitigate vehicular interference and then compensated for a magnetometer bias induced at least in part by the vehicle. Vehicle position is determined based at least in part on the compensated magnetic field magnetic measurements, the magnetic map information and the parameters of vehicle motion.