GB623009A - Line of sight stabilization - Google Patents

Abstract

623,009. Automatic control systems for radar antenna. BENDIX AVIATION CORPORATION. March 11, 1946, No. 7501. Convention date, March 14, 1945. [Class 38. (iv)[Also in Groups XXXVIII and XL (c)]. In a stabilization system for a vehiclemounted line of sight device, the device is positioned by a single servomotor to which is applied a control signal, variable in response to the degree of craft pitch and bank and to the azimuth position of the device. As shown, Fig. 1, the artificial horizon or gyro-vertical comprises a spinning member in case 28 having trunnions 30, 32 carried in the gimbal ring 34, the trunnions 36, 38 of which are supported in the frame of the vehicle, e.g. an aeroplane. Axes 40, 42 are respectively those of bank and pitch. Bank pick-off 46 (Fig. 2) comprises rotor 52 mounted on trunnion 38 and stator 54 mounted on the aircraft frame. Similarly, the pitch pick-off 44 comprises the rotor 48 on trunnion 32 and the stator 50 on the gimbal 34, the voltages generated by both pick-offs being proportional to pitch and bank angles relative to the horizontal. Stators 50, 54 are connected, respectively, to stator windings 58, 60 of the variable inductive coupling device 56, the rotor winding 70 of which rotates with the shaft 26. The latter is constantly rotated by the motor 14 and carries the platform 12 which supports the radar antenna 10. The rotor 84 of the induction motor 22, on platform 12, is coupled to the shaft 18, carrying the antenna 10, through the linkage 20 and to the rotor 88 of the variable follow-back inductive device 90, through the motion reduction mechanism 86. The stator 92 of the device 90 is connected in series with the rotor 70 and the input of amplifier 76, the output of which supplies one stator winding 78 of motor 22. A second stator winding 80 of the motor 22 is supplied through condenser 80 from the same A.C. source as the windings 48, 52 and 88. In operation, a voltage is induced in winding 70, by the pick-off signals at windings 58, 60, which is amplified at 76 and applied to the motor 22 which rotates in response until the voltage developed in winding 92 neutralizes that in 70, whereon the motor 22 stops. The plane swept by the sight axis of the antenna 10 is therefore horizontal.