In one embodiment, an apparatus includes a first magnetometer that measures a magnetic field. The apparatus includes a second magnetometer that measures the magnetic field. The first and second magnetometer are positioned a predetermined distance apart from each other in a direction. The apparatus includes computer-readable media embodying logic that access a first measurement of the magnetic field by the first magnetometer at a first time and a second measurement of the magnetic field by the second magnetometer at a second time. The logic compares the first measurement with the second measurement and, based at least in part on the comparison, determines that the first measurement approximately coincides with the second measurement. Based at least in part on the coincidence, the logic determines that a device comprising the apparatus has traversed the predetermined distance in the direction that they are positioned apart from each other.

In one embodiment, an apparatus includes a first magnetometer that measures a magnetic field. The apparatus includes a second magnetometer that measures the magnetic field. The first and second magnetometer are positioned a predetermined distance apart from each other in a direction. The apparatus includes computer-readable media embodying logic that access a first measurement of the magnetic field by the first magnetometer at a first time and a second measurement of the magnetic field by the second magnetometer at a second time. The logic compares the first measurement with the second measurement and, based at least in part on the comparison, determines that the first measurement approximately coincides with the second measurement. Based at least in part on the coincidence, the logic determines that a device comprising the apparatus has traversed the predetermined distance in the direction that they are positioned apart from each other.

A system for monitoring rotating equipment. The system includes a sensor device that acquires vibration data, acoustic emission data, temperature data, and magnetic flux data of the rotating equipment. The sensor device includes base, holding frame, first integrated circuit, housing, and power source. The first integrated circuit includes a plurality of sensors and a microcontroller configured to receive vibration data, acoustic emission data, temperature data, magnetic flux data from plurality of sensors and determine anomalies of the rotating equipment. The system further comprises an application server that receives vibration data and magnetic flux data, determines revolutions per minute (RPM) data for rotating equipment, and diagnose faults based on processed vibration data and RPM data. The application server further generates a set of features and corresponding feature values and analyzes them to diagnose faults, and predict remaining useful life of the rotating equipment.

A system for monitoring rotating equipment. The system includes a sensor device that acquires vibration data, acoustic emission data, temperature data, and magnetic flux data of the rotating equipment. The sensor device includes base, holding frame, first integrated circuit, housing, and power source. The first integrated circuit includes a plurality of sensors and a microcontroller configured to receive vibration data, acoustic emission data, temperature data, magnetic flux data from plurality of sensors and determine anomalies of the rotating equipment. The system further comprises an application server that receives vibration data and magnetic flux data, determines revolutions per minute (RPM) data for rotating equipment, and diagnose faults based on processed vibration data and RPM data. The application server further generates a set of features and corresponding feature values and analyzes them to diagnose faults, and predict remaining useful life of the rotating equipment.

In one embodiment, an apparatus includes a first magnetometer that measures a magnetic field. The apparatus includes a second magnetometer that measures the magnetic field. The first magnetometer includes a first coordinate frame with a first x axis, a first y axis, and a first z axis. The second magnetometer includes a second coordinate frame with a second x axis, a second y axis, and a second z axis. Each of one or more of the second x axis, the second y axis, or the second z axis has a predetermined orientation relative to the first x axis, the first y axis, or the first z axis.

In one embodiment, an apparatus includes a first magnetometer that measures a magnetic field. The apparatus includes a second magnetometer that measures the magnetic field. The first magnetometer includes a first coordinate frame with a first x axis, a first y axis, and a first z axis. The second magnetometer includes a second coordinate frame with a second x axis, a second y axis, and a second z axis. Each of one or more of the second x axis, the second y axis, or the second z axis has a predetermined orientation relative to the first x axis, the first y axis, or the first z axis.

A measurement system for a vehicle including a first camera defining a field of view having a corresponding optical axis, and a motion detection sensor mechanically fixed to the first camera such that the motion detection sensor is configured to detect motion of the optical axis.

A measurement system for a vehicle including a first camera defining a field of view having a corresponding optical axis, and a motion detection sensor mechanically fixed to the first camera such that the motion detection sensor is configured to detect motion of the optical axis.

A rotary transformer is provided. The transformer has a stator and a rotor. The stator has a stator core and the rotor has a rotor core sleeved in the stator core. An air gap is defined between an inner side wall of the stator core and an outer side wall of the rotor core. During rotation of the rotor, a length δ of the air gap along a circumferential direction of the transformer and a mechanical rotation angle θ of the rotor satisfy a sinusoidal function relationship containing third-harmonic components, and the length changes periodically according to the functional relationship to define a shape of the rotor core. As a result, the output signal amplitude and measurement accuracy of the position of the rotary transformer can be improved under the same maximum and minimum air gaps

A rotary transformer is provided. The transformer has a stator and a rotor. The stator has a stator core and the rotor has a rotor core sleeved in the stator core. An air gap is defined between an inner side wall of the stator core and an outer side wall of the rotor core. During rotation of the rotor, a length δ of the air gap along a circumferential direction of the transformer and a mechanical rotation angle θ of the rotor satisfy a sinusoidal function relationship containing third-harmonic components, and the length changes periodically according to the functional relationship to define a shape of the rotor core. As a result, the output signal amplitude and measurement accuracy of the position of the rotary transformer can be improved under the same maximum and minimum air gaps