A navigation instrument including an orientation angle calculation unit, in particular the first and second orientation angles, wherein the orientation angle calculation unit is configured to be able to determine the first and second orientation angles in a given order and also in reverse order; and wherein the calculation unit is arranged to be able to choose between said given order and said reverse order, to calculate the first and second orientation angles, based on a comparison between an indicator of a risk of error, quantifying a risk of instability of said unit during the determination of the first and second orientation angles, and a predetermined threshold.

Calibrating an unstable sensor of a mobile device. Systems and methods for calibrating a sensor of a mobile device determine a first estimated position of the mobile device without using any measurement from the sensor of the mobile device, generate a second estimated position of the mobile device using a measurement from the sensor, estimate a sensor error of the sensor using the first estimated position and the second estimated position, and use the sensor error to determine a calibration value for adjusting one or more measurements from the sensor.

Calibrating an unstable sensor of a mobile device. Systems and methods for calibrating a sensor of a mobile device determine a first estimated position of the mobile device without using any measurement from the sensor of the mobile device, generate a second estimated position of the mobile device using a measurement from the sensor, estimate a sensor error of the sensor using the first estimated position and the second estimated position, and use the sensor error to determine a calibration value for adjusting one or more measurements from the sensor.

Provided is an information processing apparatus including: a calculation unit that calculates a terminal coordinate system magnetic vector on the basis of a spatial coordinate system magnetic vector and a posture of a communication terminal; and a notification unit that notifies the communication terminal of the terminal coordinate system magnetic vector by non-contact communication.

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 training a predictor to predict a location of a computing device in an indoor environment incudes: receiving training data including strength of signals received from wireless access points at positions of an indoor environment, where the training data includes: a subset of labeled data including signal strength values and location labels; and a subset of unlabeled data including signal strength values and not including labels indicative of locations; training a variational autoencoder to minimize a reconstruction loss of the signal strength values of the training data, where the variational autoencoder includes encoder neural networks and decoder neural networks; and training a classification neural network to minimize a prediction loss on the labeled data, where the classification neural network generates a predicted location based on the latent variable, and where the encoder neural networks and the classification neural network form the predictor.

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.

A method for determining spatial information for a multi-segment articulated rigid body system having at least an anchored segment and a non-anchored segment coupled to the anchored segment, each segment in the multi-segment articulated rigid body system representing a respective body part of a user, the method comprising: obtaining signals recorded by a first autonomous movement sensor coupled to a body part of the user represented by the non-anchored segment; providing the obtained signals as input to a trained statistical model and obtaining corresponding output of the trained statistical model; and determining, based on the corresponding output of the trained statistical model, spatial information for at least the non-anchored segment of the multi-segment articulated rigid body system. Determining the spatial information may include determining the position and/or orientation of the non-anchored segment relative to the anchor point and/or determining a spatial relationship between the anchored and non-anchored segments.

A method for estimating the harmonization values of a magnetometer installed in a mobile machine, said magnetometer being associated with its reference coordinate system XM, YM, ZM, said method, implemented by an electronic device, comprising acquiring magnetic field values measured by the magnetometer and determining the horizontal harmonization (hx, hy) by: estimating a first angle equal to the angle between XM and the large axis of an ellipse, defined in the plane comprising the two axes XM, ZM, by said acquired field values; determining hy as being equal to said first estimated angle, estimating a second angle equal to the angle between YM and the large axis of an ellipse defined, in the plane comprising the two axes Y.sub.M, Z.sub.M, by said acquired field vector values; and determining—hx as being equal to said second estimated angle.

A method for compensating a magnetic heading includes one or more of obtaining a magnetic heading from a magnetic instrument deployed with an apparatus, determining location data for the apparatus, determining local field data based on the location data, obtaining a magnetic profile for the magnetic instrument deployed with the apparatus, and compensating the magnetic heading based the magnetic profile. For example, the magnetic profile may be responsive to perturbation of the local geomagnetic field by the apparatus, so that the compensated heading is more responsive to a directional heading of the apparatus, when deployed in the geomagnetic field. An apparatus for performing the method is also described, along with another method for calibrating the magnetic instrument when deployed with the apparatus, in order to generate the magnetic profile.