METHOD OF STIMULATING AN OSCILLATOR CONTROL FOR CAPACITIVE MEASUREMENT OF STRENGTH, ACCELERATION AND/OR ROTATION SPEED

摘要

For the drive excitation, the method for the capacitive drive excitation of oscillators in sensors for the capacitive measurement of force, acceleration and, in particular, rotation rates according to the Coriolis principle, provides according to the invention for the use of high-frequency constant-amplitude pulse packets with no DC component, the width or phase angle of which can be adjusted in order to keep the oscillator speed constant, for the purpose of resetting or correcting tolerances. As an alternative, the method may also be configured in such a way that, in the case of oscillators with pairwise excitation electrodes which are symmetrical with respect to the rotation axis, equal constant-amplitude HF voltages are applied, the frequency of which is chosen to be substantially higher than the natural frequency of the oscillator, in which case a particular resulting force of attraction on the oscillator is brought about by shifting the phase angle between the drive voltages and, in the case of rotation rate sensors working according to the closed-loop principle, system resetting can also be ensured. By virtue of the invention, problems with coupling the excitation signal into the read channel of a micromechanical oscillator system can be brought well under control.