Patent GB-499861-A (GB)
Title: A new or improved automatic piloting apparatus for air or maritime craft
IPC: G01C19/00
Filed: 1937-05-25
Abstract: 499,861. Automatic control systems; gyroscopic apparatus. RATEAU, J. May 25, 1937, Nos. 14519 and 14520. Convention dates, May 26, 1936 and Feb. 15, 1937. [Class 38 (iv)] [Also in Groups XX and XL] Steering.-An automatic piloting apparatus for air or maritime craft comprises detectors of variations of position in azimuth, incidence, and transverse inclination, electric circuits for furnishing currents which are functions of the deviations and of their successive derivatives with respect to time, and servomotors, automatically regulated in accordance with said functions and governing the controlling elements of the craft. Fig. 5 shows an arrangement in which the angle of deviation 0 and the action upon the rudders &c. are related by the equation a#+b#+c#=pr. A voltage proportional to # is supplied by the photoelectric cell 25 and resistance 26 to the grid of a valve 27, the anode current of which passes through the primary of a transformer 28. The voltage, proportional to ##, in the secondary is fed to the grid of a valve 29, the anode current of which passes through the primary of a transformer 30. The voltage, proportional to ## in the secondary of the transformer 30 is fed to the grid of a valve 31. The anode circuits of the valves 27, 29, 31 are connected together so that a current I=a#+b##+c# is amplified by the valve 32 and fed to one field winding 35 of a motor 33 of which the other winding 34 and the armature 36 are connected in parallel to a suitable source. The motor 33 is connected to a constant speed motor 37 by a differential gear 38 of which the planet cage 38a drives the rudder &c. Fig. 6 shows a modification in which # and r are related by the equation a## +b## + b## = d#r + #e#r. The output of the valve 32, Fig. 5, is passed to a resistance 41 in parallel with an inductance or condenser 42 and resistance 43. The voltage at the ends of the resistance 43 is applied to the grid of a valve 44 the anode circuit of which is connected to the winding 35 of the motor 33. In a modification the motors 33, 37, and differential gear 38 are replaced by a torque motor. Fig. 1 shows a gyro-magnetic compass for measuring deviations in azimuth. The magnetic compass card 1 is notched at a point on its periphery to intercept a light beam passing from the projector 3 via the fixed annular reflector 5 to a photo-electric cell 3 controlling through relays a motor 11. The projector 3 and cell 4 are carried by a ring 7 which is rotated round the compass bowl to follow the card 1 by gearing 8, 9 driven by the shaft 10 and motor 11. The shaft 10 is also geared to a disc 13 carrying a fork in which a ring 16 pivots on a horizontal axis. A ring 15, in which a gyro rotor 14 spins on a horizontal axis, is pivoted about a vertical axis in the ring 16 and is connected to the latter by a spiral spring 17. The gyroscope is made pendulous by eccentric weights 18 on the ring 16 and is damped by interconnected liquid bottles on the ring 15. The gyroscope indicates the mean position of the disc 13. A horizontal screen with a tapered slit is fixed to the ring 15 and modifies the light passing from a projector to the photoelectric cell 25, Fig. 5, in accordance with the deviation of the craft. In a modification means are provided to disconnect the fork from the disc 13 and the eccentric weights 18 from the ring 16 when the craft is engaged in complex evolutions. The incidence detector comprises a vane 51, Fig. 9, having two wings 53 at its tail and pivoted on a diameter of a circular supporting ring 54. The vane is geared to a shaft 55 operating a potentiometer. The control of transverse inclination is initiated by the displacements of an oil-filled drum 56, Fig. 12, arranged to take up the mean position of a pendulum 58 pivoted on the axis of the drum. The latter is connected by a spring 57 to a motor 65 controlled by a photo-electric cell 63. Light from a projector 61 passes to the cell 63 via a glass plate 60 fixed to the axle of the drum 56, a reflector 59 on the pendulum 58, a reflecting part 62 of the plate 60, and a lens 67. The cell carries a mask with a wedge-shaped aperture.