Patent GB-821519-A (GB)
Title: Improvements in or relating to automatic pilot apparatus
Inventor: WELLS JAMES ALFRED
IPC: G05D1/04
Filed: 1955-10-25
Abstract: 821,519. Automatic control systems for aircraft. MINISTER OF SUPPLY. Dec. 31, 1956 [Oct. 25,1955], No. 30452/55. Class 38 (4). In an aircraft automatic pilot rate-of-turn gyros controlling the ailerons and elevators are precessed to produce a turn, that component of the signal from the pitch rate gyro which is due to precession is prevented from controlling the elevators, and a steady component derived from the above-mentioned signal controls the ailerons. In Fig. 1, during straight and level flight, signals from the pick off RYGP of an inclined axis yaw/roll rate gyro RYG are applied to a magnetic amplifier AA controlling aircraft ailerons (not shown), and signals from the pickoff PGP of a pitch rate gyro PG are applied to a magnetic amplifier EA controlling the aircraft elevators (not shown). Signals from pickoffs HDP and HRP associated with devices HD and HR respectively responsive to altitude and rate of change of altitude, are also applied to elevator amplifier EA. In addition, signals from a pick-off SSP associated with a side-slip detector SS are applied to a winding RYSS to eliminate side-slip by precessing the yaw/roll gyro. Follow-up signals from potentiometers FBA and FBE operated by the ailerons and elevators are respectively applied to the aileron and elevator amplifiers AA and EA. Rate feedback (not shown) is also provided from the ailerons and elevators. When a turn is desired, switches TS, PGS and AVPS are operated manually from the positions shown to positions corresponding to the sense of turn until the desired rate of turn has been set. The movement of switch TS causes a motor TM to adjust potentiometers RYTP and PTP, thereby energizing windings RYT and PT to produce the turn by precessing the yaw/roll and pitch rate gyros. Signals from potentiometer PTP are also applied directly to the elevator amplifier EA and signals dependent on the speed of motor TM are applied to aileron amplifier AA to boost the turn initially. The movement of switch PGS (a) introduces a condenser EC so that steady signals from pick-off PGP due to precession of the pitch rate gyro are not applied to elevator amplifier EA and (b) applies the signals from pick-off PGP through a motor averaging circuit AV to the aileron amplifier AA in the appropriate sense by virtue of the moved switch AVPS. When it is desired to climb or dive, switches CDS and HDS are operated manually from the positions shown to positions corresponding to climb or dive until the desired rate has been set. The movement of switch HDS eliminates the signals from altitude sensitive device HD. The movement of switch CDS causes a motor CDM to adjust (a) potentiometer CDP to apply a climb or dive signal to the elevator amplifier EA and (b) potentiometer TCDP to apply a signal from potentiometer RYTP to precession winding RYSS of the yaw/roll rate gyro if the aircraft is both turning and climbing or diving. Signals dependent on the speed of motor CDM are also applied to elevator amplifier EA to boost climb or dive initially. In a modification signals from the pitch rate gyro are also applied directly to the aileron amplifier during turns. Elimination of the control of the aileron amplifier by the yaw/ roll gyro during turns, at least when the bank angle exceeds a predetermined value is referred to.