GB957948A - Control systems for navigable craft - Google Patents

Abstract

957,948. Automatic control of navigable craft. SPERRY RAND CORPORATION. July 26, 1960, No. 25902/60. Heading G3R In a system for automatically maintaining a desired height or depth and pitch attitude of a craft, signals corresponding to errors in both of these quantities combine to control both rear and forward control surfaces on the craft. In Fig. 1 the pitch angle of a submarine is maintained constant by a vertical gyroscope 16 adjusting a differential inductive device 11 the output of which is applied through a servomotor system 17 to control stern driving planes 26 and bow driving planes 29 through servomotor systems 20, 24 and 21, 27 respectively. The pitch angle may be trimmed level by operation of a hand wheel 14 which adjusts an element in differential inductive device 11 and is associated with a trim indicator (not shown). Stabilizing error rate signals from tachometer generators in a unit 19 driven by servomotor system 17, which are modified in dependence on craft speed by utilizing the output of the ship's log to control the generator fields, are applied to servomotor systems 20 and 21. The output of servomotor system 17 is also integrated by a motor unit 22 and applied to servomotor systems 20 and 21 to eliminate persistent effects. To prevent stern down effect during turns an adjustable rate of turn signal is developed by a servomotor system 23 from a compass signal and applied to servomotor systems 20 and 21. To maintain the submarine at such a depth that its snorkel tube is correctly positioned a mechanical differential gear 1, which is controlled through a servomotor system 5 from a hydrostatic pressuresensitive depth gauge 4 and by a hand wheel 2 for setting the required depth, drives a potentiometer 7, of adjustable sensitivity, the output of which controls differential inductive device 11 through a servomotor system. 8. An adjustable rate of change of depth signal developed by a tachometer generator 9 is also applied to servomotor system 8. To maintain a constant pressure within the submarine hull despite variations due for example, to spray on the snorkel, a mechanical differential gear 30, which is controlled through a servomotor system 35 from a hull air pressure gauge 33 and by a hand wheel 31 for setting the required pressure, drives a potentiometer 36, of adjustable sensitivity, the output of which also controls differential inductive device 11 through servomotor system 8 if a switch 37 is closed manually. The effect of signals from the depth gauge and the hull air pressure gauge is limited by adjustable limit stops 12 associated with the servomotor of system 8 which drives through a slipping clutch. If the depth error exceeds one predetermined value, a switch (not shown) operated by differential gear 1 prevents further operation of motor integrator 22, which, if a greater predetermined depth error is exceeded further switches, similarly operated, reset the integrator to zero.