GB1075705A - Attitude control system for sounding rockets - Google Patents

Abstract

1,075,705. Controlling spacecraft. AEROJETGENERAL CORPORATION. Sept. 22, 1964, No. 38612/64. Heading B7G. A ballistic vehicle has two gyroscopes providing roll, pitch and yaw reference attitudes, jet nozzles for rotating the vehicle about roll, pitch and yaw axes to reduce the vehicle attitude error, and a timer for sequentially varying the reference attitudes by applying torques to the gyros to cause the vehicle to be orientated in a succession of attitudes. The vehicle described is a sounding rocket in which the succession of attitudes is used for observations. Control construction.-The rocket body has two pairs of tangentially arranged roll control nozzles (21a, 21b and 22a, 22b) in an attitude control section (20, Figs. 1 and 2, not shown) and one pair each of yaw and pitch control nozzles in the tail of the rocket. The gas supply for the nozzles is taken from pressurization tanks for the launch propellant, and is controlled by solenoid valves. The two gyroscopes (35, 36) have outer gimbals (35b, 36b) rotatable about axes parallel to the roll axis, and inner gimbals (35e, 36e) rotatable about pitch and yaw axes. The attitude control section also contains a programmer 40 comprising a series of rotary switches (40a) driven by a stepper motor (51) controlled by a timer (50). Pitch, roll and yaw rate gyros are also provided, and torque motors T and synchros S respectively apply torque to the gyros (35, 36) to change their reference attitudes and direct changes in the attitudes. Control programme.-The rocket is spinstabilized during its ascent and this spin is taken off when the programmer is actuated (by a switch (45) sensitive to the acceleration change on burn-out) by operation of a solenoid valve (60) under the control of the roll rate gyro (63). In the next stage, the attitudes of the gyros (35, 36) are changed by a programme corrector set up immediately prior to launch to correct, e.g. for launch tower tilt. Roll, pitch and yaw correction signals are supplied by leads (46, 44, 45) to torque motors (35d, 35c and 36c) and the resultant precession of the gyros produces correcting torques from the control nozzles until the resultant outputs of the roll rate gyro (63) and synchro (35f), the pitch rate gyro and synchro (35g), and the yaw rate gyro and synchro (36g), are washed out. The synchro (36c) and torque motor (36d) form a servo loop by which the gyro (36) is precessed to keep the axis of the inner gimbal parallel with the rocket yaw axis. In subsequent stages in the programme controlled by the timer (50) appropriately valued resistors (40b) are inserted in sequence in the lines (46, 44, 45) to the roll, pitch and yaw torque motors (35d, 35c and 35f) respectively to rotate the rocket to a desired orientation, which is held for a predetermined time before the rocket is re-orientated.