Litef Gmbh

Werner Schroeder

In a method for electronic tuning of the frequency of the read oscillation to the frequency of the stimulation oscillation in a Coriolis gyro, the resonator of the Coriolis gyro has a disturbance force applied to it such that the stimulation oscillation remains essentially uninfluenced. The read oscillation is changed so that a read signal that represents the read oscillation contains a corresponding disturbance component. The frequency of the read oscillation is controlled so that the magnitude of the disturbance component contained in the read signal is a minimum.

Method for electronically tuning the readout vibration of a coriolis gyroscope

In a method for electronic tuning of the frequency of the read oscillation to the frequency of the stimulation oscillation in a Coriolis gyro the resonator of the Coriolis gyro has a disturbance force applied to it such that the stimulation oscillation remains essentially uninfluenced. The read oscillation is changed so that a read signal that represents the read oscillation contains a corresponding disturbance component. The disturbance force is defined as the force caused by the signal noise in the read signal. The frequency of the read oscillation is controlled so that the strength of the disturbance component contained in the read signal is a minimum.

Method for electronic tuning of the read oscillation frequency of a coriolis gyro

In a method for determining the zero-point error of a Coriolis gyro, the resonator of the Coriolis gyro has a disturbance force applied to it such that a change in the stimulation oscillation of the resonator is brought about. A change in the read oscillation of the resonator, caused by a partial component of the disturbance force, is extracted from a read signal which represents the read oscillation of the resonator as a measure of the zero-point error.

Method for detecting a zero-point error of a coriolis gyroscope and coriolis gyroscope using said method

A method for determination of the zero error of a Coriolis gyro. Appropriate disturbance forces are applied to the resonator of the Coriolis gyro such that at least one natural oscillation of the resonator is stimulated that differs from the stimulating and read oscillations. A change in a read signal which represents the read oscillation and results from the stimulation of the at least one natural oscillation is determined as a measure of the zero error.

Method for determining a zero-point error in a vibratory gyroscope

In a method for electronic tuning of the frequency of the read oscillation to the frequency of the stimulation oscillation in a Coriolis gyro, the resonator of the Coriolis gyro has a disturbance force applied to it such that the stimulation oscillation remains essentially uninfluenced. The read oscillation is changed so that a read signal that represents the read oscillation contains a corresponding disturbance component. The frequency of the read oscillation is controlled so that the phase shift between the disturbance signal and the disturbance component contained in the read signal is a minimum.

Method for electronically adjusting the selective oscillation frequency of a Coriolis gyro

A method for compensation of the zero error of a Coriolis gyro. The frequency of the read oscillation is modulated. The output signal from a rotation rate control loop or quadrature control loop for the Coriolis gyro is demodulated in synchronism with the modulation of the frequency of the read oscillation to obtain an auxiliary signal. The auxiliary signal is a measure of the zero error. A compensation signal is produced and passed to the input of the rotation rate control loop or quadrature control loop, with the compensation signal being controlled such that the magnitude of the auxiliary signal is as small as possible.

Method for compensation for a zero error in a coriolis gyro

A synchronous demodulation system with digital signal output contains a summation circuit receiving an input signal to be demodulated and a control signal. The output of the summation circuit is applied to a synchronous demodulator which feeds into a controller. The controller comprises an integrator, which precedes an A/D converter and a processor that acquires the output pulses of the A/D converter. The processor drives a D/A converter supplying the control signal to the summation circuit so that the summation of the input signal and the output of the D/A converter, averaged over time, leads to an (approximately) zero signal in the synchronous demodulator. Due to digital control the circuit is distinguished by a large dynamic range and high accuracy with simultaneous insensitivity.

Synchronous demodulation system with digital output

A rotation rate readout method employing a passive optical resonator. The ring resonator is operated at approximate resonance in reflection and rotation rate-dependent phase shifts are detected, in particular as first harmonics, in the resonator. Two partial light beams are first frequency shifted by equal and opposite amounts, such frequency shift being modulated. Light components coupled out of the resonator pass through a mode filter in the opposite direction and are detected as an interference signal by an opto-electronic converter. The latter signal is demodulated with respect to the modulation frequency or its harmonics and the rotation rate signal obtained therefrom. Self-compensation of the optical and electronic readout systems may be attained by periodic brief and strong damping of the ring resonator. In contrast with known methods wherein two channels are separately processed and two mode filters required, the interference signal is processed in accordance with the invention requiring only a single mode filter.

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Ettenheim, Germany

Werner Schroeder