Honeywell G.m.b.h.

Other

Honeywell International Inc.

Andrew J Karpinski, Jr

Steven C Albers

Timothy J Callaghan

Steve Albers

Richard R Desmarais

In a ring laser gyro (RLG), the dither pick off signal is applied to a variable gain amplifier, producing an output that controls the amplitude of the motion of a dither motor connected to the gyro. A square wave is generated from the dither pick off signal and applied to a signal processor with clockwise and counterclockwise signals produced by the motion of the gyro. The signal processor controls a multiplexer to select the gain for the variable gain amplifier by counting the clockwise and counterclockwise signals produced by the gyro motion in a interval (number of whole periods of dither motion) determined by counting the square wave signal produced from the dither pick off signal.

Automatic dither pickoff gain select

In an ring laser gyro, a path length modulation signal is applied to an amplifier with two gain levels and the amplifier's output is added to a path length transducer drive signal that changes the gyro's path length. When a path length reset signal is produced, the higher gain signal is selected and maintained for a short interval after the reset signal.

Enchancing path length resets in a ring laser gyro

An integrator in a ring laser gyro that produces an output for changing the path length is reset synchronously with a gyro dither signal to reduce gyro errors from the dithering operation during the reset.

Reducing dither induced errors from path length control resets in a ring

An interface circuit is provided to allow substitution of digital output rotation sensors such as fiber optic gyroscopes or ring laser gyroscopes in place of spinning mass gyroscopes. The pulses generated from the fiber optic gyroscope, or from a ring laser gyroscope are converted to a voltage representative of volts per degrees per second and are summed with an inverted volts per degrees per second at an integrating summing amplifier to result in an error signal in volts per degrees per second when there is a difference between the actual output of the gyroscope and the command signal.

Digital to analog interface conversion circuit

A ring laser gyroscope system includes light intensity detecting devices for detecting intensity of laser beams in the gyroscope. A computer processes the output and calculates the amount of backscatter in each beam. The measurement of backscatter is used to calculate the amount of movement required of mirrors in the gyroscope to change the path length of the laser beams an amount sufficient to minimize the backscatter in each. By minimizing backscatter, random walk of the laser beam is reduced.

Device and method for reducing angular random walk in a ring laser

A control method is disclosed which extends random drift improvement control to operation at high input rates. Traditional RDI control fails at high input rates due to the diminishing amplitude of the SBS; therefore, the control is lost. The present invention continuously samples the RDI control position and holds this RDI control position at its last previously recorded optimum value while the ring laser gyroscope is subjected to high input rates.

Sample and hold control method and apparatus for improved scale factor

A system and method is provided which minimizes angular random walk or bias occurring in ring laser gyroscopes as a result of temperature changes. Temperature is known to affect components in a ring laser gyroscope in a manner which increases angular random walk or bias. By detecting temperature and causing movable path length transducers to move mirrors in the gyroscope into a position previously determined for a given temperature, angular random walk or bias is minimized for the given temperature.

Method and system for minimizing angular random walk or bias in a ring

Piezoelectric transducer drive apparatus applies varying pulse rates to the terminals of the transducer with the transducer acting as a capacitor and integrating the applied pulses. A conductive path from each transducer terminal remover charge from each terminal. Control of the voltage across the transducer is achieved by individually varying the pulse rates applied to each of the transducer terminals.

Piezoelectric transducer drive

Control apparatus for an RLG dither motor includes a digital phase shifter for providing a clock signal related to the RLG position signal. A rate pulse generator for receiving an amplitude word signal generated by a processor at intervals determined by the clock signal and providing a pulse rate signal related to the amplitude word signal. The pulse rate signal is combined with the RLG position signal to provide a second pulse rate signal which is integrated to provide a triangular dither drive signal.

Triangular dither drive apparatus for a ring laser gyroscope

A ring laser angular rate sensor apparatus includes ring laser apparatus for generating a pair of counter-propagating laser beams about a closed-loop path where the laser beam intensity varies as a function of drive voltage. Path length control apparatus including a transducer drive amplifier apparatus provides a drive signal for variably adjusting the length of the closed loop path so as to acquire a peak laser intensity. Reset acceleration apparatus for selectively applying a bias signal to the path length control apparatus rapidly forces the drive signal in one direction thereby causing the laser intensity corresponding to the drive signal to increase and allows the path length control apparatus to acquire a laser intensity peak. In one embodiment of the invention the reset acceleration apparatus includes apparatus for comparing a predetermined reference signal with a laser intensity signal and switching apparatus, coupled to and controlled by the comparing apparatus, for applying the bias signal. The bias signal is applied by the comparing apparatus when the laser intensity signal falls below the level of the predetermined reference signal.

Laser path length control reset acceleration circuit

The present invention inhibits quenching of a laser following a radiation event by providing a radiation sensing arrangement connected to the discharge current control circuitry controlling the discharge current of the laser, for sensing a radiation event and for controlling the discharge current control circuitry in such a way that quenching of the laser for a predetermined amount of time after a radiation event is inhibited.

System for inhibiting quenching of laser beams in response to radiation

An RLG signal processing system in which RLG quadrature errors are corrected by adding to one signal a portion of the other signal whose magnitude is a function of the magnitude of the quadrature error. Output buffer amplifiers restore the output signal to equal amplitude.

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Clearwater, FL, United States of America

Andrew J Karpinski, Jr