GB715333A - Improvements in or relating to automatic flight control systems - Google Patents

Abstract

715,333. Automatic aircraft control systems. SPERRY CORPORATION. Feb. 28, 1948 [March 15, 1947], No. 22280/51. Divided out of 715,312. Class 38(4) An aircraft may be caused to execute banked turns by either the automatic adjustment of the bank angle in accordance with a predetermined rate of turn or the adjustment of the rate of turn to correspond to a given bank angle; a spiral turn can also be effected. As shown, the output from flux valve 37 is, during straight flight, applied through the differential selsyn 44 to the input of computor 18 and the craft is steered automatically along a predetermined course. The ailerons are operated by a signal generated at the pickoff 63 operated by gyro 62 which is precessed by torque motors 61, 61<SP>1</SP>. Motor 61 is energized by a signal proportional to the difference between the craft bank angle detected at the pick-off 24 of gyrovertical 23 and the required bank angle as derived by computor 18 from the predetermined rate of turn applied at knob 11. Motor 61<SP>1</SP> is energized by a signal proportional to the product of the angle of elevation, derived at sine selsyn 58 and the predetermined rate of turn derived from 12. Rudder operation is effected by pick-off 75 of gyro 74 precessed by torque motor 73 energized by the predetermined rate of turn signal generator at 10, through the cosine selsyn 68 on the pitch axis of gyro 23 and through cosine selsyn 64, on the roll axis. The elevators are similarly controlled from pick-off 85 by gyro 84 precessed by torque motor 83 energized through cosine selsyn 78 and sine selsyn. 65. A climbing turn is initiated by movement of 12 about axis 86 and a signal produced at 87 is applied to the rudder and elevators via selsyns 91, 94, 95. At the computor 18 signals proportional to the predetermined rate of turn and the airspeed are applied to a cosine selsyn on the pitch axis of 23 the output from which is applied to a device producing an angular displacement the tangent of which is proportional to the product of the applied signals. Short period control of the aircraft is effected by the gyros 62, 84, 74 and only if persistent errors are developed do the signals from the gyro-vertical 23 effect control. During steady flight the potentiometer 100 is shorted out and no signals are applied to 61 from 23. In the alternative arrangement (not shown) the control knob may be operated to give a predetermined angle of bank and elevation; upon a given bank angle signal being applied to the ailerons, a selsyn operated by the gyro vertical supplies a signal to a computing device, the output of which is proportional. to a rate of turn which corresponds to the predetermined bank angle and which is applied to the rudder control system. The torqued gyros in both embodiment may be replaced by accelerometers.