An algorithm and architecture for sense transfer function estimation injects one or more test signals from a signal generator into a MEMS gyroscope to detect an output signal (e.g., proof mass output sense signal), including an in-phase (e.g., Coriolis) component and a quadrature component. The in-phase and quadrature components are encoded with reference signals to determine phase and/or gain variation and are processed via a variety of components (e.g., matrix rotation, digital gain, tones demodulator, transfer function errors estimation, etc.) to estimate a sense transfer function of the MEMS (e.g., H.sub.s(f.sub.d)) and corresponding phase and/or gain offset of H.sub.s(f.sub.d). The in-phase and quadrature components are also compensated for phase and/or gain offset by system components.

An algorithm and architecture for sense transfer function estimation injects one or more test signals from a signal generator into a MEMS gyroscope to detect an output signal (e.g., proof mass output sense signal), including an in-phase (e.g., Coriolis) component and a quadrature component. The in-phase and quadrature components are encoded with reference signals to determine phase and/or gain variation and are processed via a variety of components (e.g., matrix rotation, digital gain, tones demodulator, transfer function errors estimation, etc.) to estimate a sense transfer function of the MEMS (e.g., H.sub.s(f.sub.d)) and corresponding phase and/or gain offset of H.sub.s(f.sub.d). The in-phase and quadrature components are also compensated for phase and/or gain offset by system components.

Systems and methods for calibrating multiple inertial measurement units on a system include calibrating a first of the inertial measurement units relative to the system using a first calibration model, and calibrating the remaining inertial measurement unit(s) relative to the first inertial measurement unit using a second calibration model. The calibration of the remaining inertial measurement unit(s) to the first inertial measurement unit can be based on a rigid body model by aligning a rotational velocity of the first inertial measurement unit with a rotational velocity of the remaining inertial measurement unit(s).

Pressure-based estimation of a mobile device altitude or calibration of a pressure sensor involves machines that determine if a reference-level pressure value based on one or more measurements of pressure from a network of weather stations should or should not be used to calibrate a pressure sensor of a mobile device or to estimate an altitude of the mobile device. If the reference-level pressure value should be used, the reference-level pressure value is used to calibrate a pressure sensor of a mobile device or to estimate an altitude of the mobile device. If the reference-level pressure value should not be used, a trend in pressure is determined, an estimated reference-level pressure value based on the trend is determined, and the estimated reference-level pressure value is used to calibrate a pressure sensor of a mobile device or to estimate an altitude of the mobile device.

A method for stabilizing a magnetic field of an inertial measurement unit (IMU), is provided that includes initializing accelerometer and gyroscope (AG) heading data for the IMU and initializing accelerometer, gyroscope and magnetometer (AGM) heading data for the IMU. Determining whether a tracking state exists and completing processing of the AG heading data and the AGM heading data if the tracking state does not exist. Calculating a magnetic field error if the tracking state exists.

An apparatus for simulating an oscillating flight path is provided. The apparatus comprises a slide extending along a first axis; a support structure slidably coupled to the slide; and a table connected to the support structure. The support structure is operable to move along the slide. The table is coupled to the support structure and operable to rotate about a second axis orthogonal to the first axis. The table comprises a surface that is parallel to the second axis and that is operable to rotate about a third axis orthogonal to the second axis.

Motion can be induced at a vehicle, e.g., by actuating components of an active suspension system, and first sensor data and second sensor data representing an environment of the vehicle can be captured at a first position and a second position, respectively, resulting from the induced motion. A second sensor can determine motion information associated with the first position and the second position. Calibration information about the sensor, the first sensor data, and the motion information can be used to determine an expectation of sensor data at the second position. A calibration error can be the difference between the second sensor data and the expected sensor data.

Provided is a ranging sensor calibration system that can execute a calibration operation during travel at low cost and without adding a special configuration. This ranging sensor calibration system is provided with a plurality of ranging sensors that are installed facing at least a first direction along a direction of travel of a vehicle and a second direction that is an opposite direction to the first direction, and are configured to be able to measure a distance; and a calibration processing unit that configures the plurality of ranging sensors. The calibration processing unit is configured to calibrate the plurality of ranging sensors on the basis of a distance between a plurality of calibration targets disposed near a travel path for the vehicle, a distance between the plurality of ranging sensors, and a distance measured by each of the plurality of ranging sensors.

Aspects presented herein may enable an electronic device to determine gyroscope biases and calibrate a gyroscope without a magnetometer or without relying on data generated from a magnetometer. In one aspect, an apparatus estimates a set of gyroscopic biases for a plurality of temperatures or temperature ranges to create a mapping that maps the plurality of temperatures or temperature ranges to the set of gyroscopic biases. The apparatus monitors temperatures of a gyroscope via a gyroscope temperature sensor. The apparatus calibrates the gyroscope in response to the gyroscope changing from a first temperature to a second temperature based on the mapping or based on a predicted value derived from the mapping. In some aspects, the apparatus calculates a DR trajectory of the apparatus based at least in part on the calibrated gyroscope and the accelerometer without using a magnetometer or without using data generated from the magnetometer.

An improved total field calibration system and method is disclosed for reducing the rotational misalignment between magnetic and gravity sensors in a directional sensing system. A method of calibrating a tri-axial directional sensor comprising orthonormal accelerometers and orthonormal magnetometers, comprises measuring Earth's magnetic and gravity fields with said directional sensor in at least 4 sensor orientations; obtaining at least one reference field value of dip drift of Earth's magnetic field from at least one source independent of said directional sensor corresponding to said orientations; and, determining and applying rotational misalignments between said magnetometers and said accelerometers so that measured magnetic dip drifts are substantially equal to said reference values. The calibration process can be performed without monitoring the declination change during the calibration process. Directional sensing systems can be calibrated accurately during a period when the Earth's magnetic field changes rapidly.