GB806303A - Improvements in automatic condition control apparatus - Google Patents

Abstract

806,303. Automatic steering control systems. MINNEAPOLIS-HONEYWELL REGULATOR CO. March 31, 1955 [April 1, 1954], No. 9442/55. Class 38 (4). In a system for automatically maintaining a variable at a desired value, an error detector, normally coupled to a generator signals from which correct the variable through a servo system, is automatically uncoupled during manual control of the servo system, the error signal produced by the generator being maintained at its value at the instant of changeover. In an automatic aircraft pilot, Fig. 1, bank altitude is maintained by a gyro vertical 35 operating a potentiometer 28 in the input circuit of an amplifier relay 16 controlling a reversible servomotor 14 operating the ailerons. Positional follow-up is provided by a potentiometer 22. Co-ordinated control of the rudder is obtained by also applying the output of potentiometer 28 through a potentiometer 109 to the input of an amplifier-relay 94 controlling rudder servomotor 90. Positional follow-up in the rudder channel is provided by a potentiometer 98 and rudder trim by a potentiometer 101. A predetermined course is maintained by a directional gyro 66 movements of which on deviation from course are transformed into movements of a shaft 50 through an electric correspondence control system involving an inductive pick-off 77, an amplifier 83 and a servomotor 85. Rate and positional follow-up for servomotor 85 is provided by generator 87 and inductive device 80 respectively. Automatic course correction is effected by shaft 50 adjusting a potentiometer 44 in the input of aileron amplifier-relay 16. The course may be altered by manually operating a potentiometer 39 in the input of amplifier-relay 16 and the opening of contacts 129 when this is done de-energizes an electromagnetic clutch 51 between shaft 50 and potentiometer 44 to prevent control by gyro 66. To facilitate smooth changeover, a brake 56 maintains potentiometer 44 in the position it had at the time of changeover to manual control. If, however, it is desired to set a new course by direct manual control of the rudder and ailerons, a push button 124 is operated momentarily to energize brake release winding 58 so that potentiometer 44 is re-centralized by springs 60, 61. In a modification in which gyro 66 directly operates potentiometer 44 through clutch 51, springs 60, 61 are dispensed with to avoid load on the gyro and recentralization is effected by pressure of a plunger on a heart-shaped cam when a solenoid, which also releases the brake, is de-energized by the operation of push button 124.