GB810440A - Improvements in or relating to apparatus responsive to angular velocities of a platform on which it is mounted - Google Patents

Abstract

810,440. Automatic control systems for gyros. SPERRY GYROSCOPE CO. Ltd. Sept. 9, 1949 [Sept. 9, 1948], No. 23745/48. Class 38 (4). [Also in Group XX] Gyroscopic apparatus stabilizing a platform 1 on, say, an aircraft, about perpendicular axes A, A<SP>1</SP>, B, B<SP>1</SP>, comprises a continuously rotated turntable 6 carrying a rateof-turn gyro 10. The housing of gyro 10 is carried in bearings 11 on the turntable 6, the axis of which normally coincides with the spin axis of the gyro 10. Angular displacement of the craft about A, A<SP>1</SP> or B, B<SP>1</SP> results in precession of the gyro 10, which produces a cyclically varying signal in inductive pick-off devices 13, 14, which signal is amplified and applied to a coil 17. Coils 19, 20 mounted on platform 1 are arranged parallel to B, B<SP>1</SP>, A, A<SP>1</SP> when the plane containing their axes is parallel to the plane containing B, B<SP>1</SP>, A, A<SP>1</SP>, and coil 17 is rotated synchronously with its axis parallel to D, D<SP>1</SP>, coils 17, 19, 20 forming a sine-cosine resolver. The amplified outputs from coils 19, 20 energize stabilizing torque motors 4, 5. High accuracy is claimed as irregularities of the gyro 10 produce opposing signals that cancel. The angular momentum of the turntable 6 is high, forming a stabilizing gyro in itself, affording an averaging control over the cyclic variation of the signal produced in the resolver 17, 19, 20. Alternatively or additionally, averaging control may be provided by electrically derived averages of the signal produced.