Patent GB-1355326-A (GB)
Title: Missile steering device
IPC: G05D1/12
Filed: 1962-08-22
Abstract: 1355326 Automatic control of course FLUGGERATEWERK BODENSEE GmbH 22 Aug 1962 32351/62 Heading G3R A device for steering a missile towards a target, comprises a free gyroscope, a target area scanner rotating with the gyro rotor and supplying periodic signals, the phase position of which depends on the direction of the off-centre position of the target related to the gyro axis, and a torque emitter which can be controlled by the signals from the target area scanner and by which, periodically with the frequency of rotation of the gyroscope, torques can be produced about a prescribed gyro rotor axis perpendicular to the axis of rotation and on which the signals are so applied that the gyroscope precesses towards the target, characterized in that the signals supplied by the target area scanner and causing the precessional movement of the gyroscope, simultaneously act as error signals on the steering system of the missile. The gyroscope and the manner in which it operates to maintain its axis aligned with the line of sight between the missile and the target is disclosed in Specification 1351279. The present invention serves to maintain the missile in a collision course with the target by utilizing the signals supplied by the target area scanner, which signals are proportional to the alteration speed of the line of sight, to change the course of the missile and reduce the change in the line of sight to zero. As shown in Fig. 6 the target area scanner signals derived from a detector 520 sensitive to missile radiation are applied to the gyro precessing coils 548', 548" through a conventional amplifier and rectifier 800 including tubes arranged in push-pull having anodes 802, 804. The coils 548', 548" are oppositely wound upon one another so that D.C. components of the push-pull amplifier current produce a zero magnetic field whereas the A.C. components are additive and produce the precessional torque. The junction between output resistors 806, 808, of the conventional push-pull amplifier, is connected to a voltage source B+ and the D.C. components of current from the push-pull amplifier are again cancelled and the A.C. components applied in common to the inputs of a pair of phase sensitive demodulator circuits 810, 812. Phase sensitive demodulator 810 consists of four resistors 816, 820, 824 and 828 and four silicon diodes 814, 818, 822 and 826, whilst phase sensitive demodulator 812 consists of resistors 832, 836, 840 and 844, and four silicon diodes 830, 834, 838 and 842. A reference signal is produced for each demodulator 810, 812, by means of two pairs of reference coils 850, 852; 854, 856; respectively connected to a further input of demodulator circuits 810,_812. These reference coils 850, 852; 854, 856; are located circumferentially around a permanent magnet 522 Fig. 1, (not shown) rotatable with the gyro and in such a direction that the signals in these coils represent the position of the magnet 522 with respect to missile co-ordinates. The output of the demodulators 810, 812 is tapped between the iunction X of resistors 846, 848, and the junctions Y, Z, of the reference coils 850, 852; 854, 856; respectively. Whenever an A.C. component of current capable of effecting a precession of the gyro, is applied to the demodulating circuits 810, 812, a potential difference occurs between point X and point Y or point Z, to produce a D. C. component of current in line a or line b according to the amplitude of the input signals to the demodulator circuits and the phase difference between the input voltage and the reference voltage. Any D.C. components of current on lines a or b are applied to the input winding of magnetic amplifier 864, 862 resistors 860, 858 respectively, to produce a signal in the output winding thereof which is applied via amplifier 803, 805, respectively to servo valve electromagnet 809, 807 respectively which generate pressures on crank arms or mechanical linkages attached to the yaw or pitch fins of the missile to control the operation thereof and the torque applied thereto. In a modification Fig. 7, (not shown) the bridge circuit is replaced by magnetic switches.