MICRO-MECHANICAL ROTATIONAL-SPEED SENSOR

摘要

The invention relates to a micro-mechanical rotational speed sensor comprising a sensor structure that reacts to an externally acting rotational speed. The problem associated with known sensors is that as a result of the sensor construction, the output signal that characterises the rotational speed takes the form of an amplitude modulated signal and as such is particularly susceptible to interference and thus has a poor signal-to-noise ratio. To resolve said problem, a resonator structure with at least one inherent frequency is provided and the inventive sensor structure is mechanically connected to the resonator structure, in such a way that an acting rotational speed alters the inherent frequency of the resonator structure. Said alteration in the inherent frequency of the resonator structure or a variable that is derived from the inherent frequency of the resonator structure is evaluated as a measurement of the rotational speed.