Sensor for sensing accelerations

摘要

Sensors (1) for sensing accelerations are provided with accelerometers (11) for measuring accelerations, with magnetometers (12) for measuring magnetic fields, and with processors (13) for, in response to acceleration measurements and magnetic field measurements, judging the accelerations. The processors (13) may comprise acceleration units (14) for comparing acceleration signals with acceleration thresholds, and magnetic field units (15) for comparing changes of magnetic field signals per time interval with rate thresholds. The processors (13) may further comprise decision units (17) for, in response to comparison results from the acceleration units (14) and the magnetic field units (15), deciding whether a total acceleration forms part of a tumbling free-fall or a non-tumbling free-fall or not. The processors (13) may yet further comprise distinguishing units (18) and control units (19). Devices (2) may comprise sensors (1).

主权项

1. A sensor for sensing accelerations, which sensor comprises:
an accelerometer for measuring an acceleration, a magnetometer for measuring a magnetic field, and a processor for, in response to at least one acceleration measurement measured by the accelerometer and at least one magnetic field measurement measured by the magnetometer, judging the acceleration, the processor comprising:
an acceleration unit for comparing the at least one acceleration measurement measured by the accelerometer with at least one acceleration threshold,a magnetic field unit for comparing at least one change of the at least one magnetic field measurement measured by the magnetometer per time interval with at least one rate threshold, anda decision unit for, in response to comparison results from the acceleration unit and the magnetic field unit, deciding whether a total acceleration forms part of a tumbling free-fall or a non-tumbling free-fall, wherein the decision unit is configured to decide that the total acceleration forms part of a non-tumbling free-fall if the deviation of the total acceleration from a fixed acceleration value is larger than a first threshold while the rate of change of each of the at least one magnetic field measurement is smaller than the at least one rate threshold and if the time integral of the deviation of the total acceleration is larger than a second threshold.