Patent GB-776829-A (GB)
Title: Flight system
IPC: B64C29/00
Filed: 1954-03-10
Abstract: 776,829. Automatic control systems. HAMILTON, S. March 10, 1954 [April 22, 1953], No. 6999/54. Class 38 (4). Three forms of flight vehicle are described in which gravity is overcome by vertical thrust produced by a plurality of reaction jet propulsion units, and in which the thrust of each propulsion unit is automatically controlled in dependence on rotation of the vehicle about both roll and pitch axes. In one form of vehicle vertical propulsion units 2, 3, 4, 5, Fig. 1, are located at the four corners of the flight vehicle. In another form of vehicle, Fig. 4 (not shown), a vertical propulsion unit is located at each side of the vehicle on the pitch axis and a vertical propulsion unit is located at the front, and rear of the vehicle on the roll axis. In a third form of vehicle, Fig. 12 (not shown), three vertical propulsion units are located at the corners of a triangle, one side of which is either parallel to or at right angles to the pitch axis. At least one further horizontal reaction jet propulsion unit, e.g. 6, Fig. 1, produces horizontal movement of the vehicle. Roll and pitch control.-A gyro-vertical is associated with an electrical system for controlling the relative thrust of the vertical propulsion units, thereby automatically maintaining the flight vehicle level with reference to longitudinal and trnnsverse horizontal axes. Potentiometer pick-offs associated with the roll axis of the gyro-vertical apply A.C. signals of the appropriate phase sense to vertical thrust controlling amplifiers which relatively adjust the thrusts of the propulsion units. to correct any roll without altering the total thrust. The thrust controlling amplifier associated with each propulsion unit supplies an electric servomotor adjusting a potentiometer, the D.C. output of which, e.g. applied at 149, 150, Fig. 6, controls the energization of a motor 164 driving fuel and oxidizing agent pumps 169, 139, the setting of fuel and oxidizing agent by-pass valves 171, 141, and the opening of fuel and oxidizing agent injector nozzles 176, 148. Adjustable rate feedback is provided by a tacho-generator associated with each servomotor. An alternator associated with the roll axis of the gyro vertical introduces the necessary damping which is automatically reduced by a rheostat associated with the roll axis of the gyro when the flight vehicle is inclined about the roll axis. Further potentiometer pick-offs and an alternator associated with the pitch axis of the gyro-vertical correct any pitching of the flight vehicle in a similar manner. Heading control.-The heading of the flight vehicle is automatically controlled by a directional gyro associated with a variable inductive pick-off the output of which controls, through an amplifier and servomotor, the orientation of the horizontal propulsion unit about a vertical axis, e.g. 25, Fig. 1. The variable inductive pick-off is also either manually adjustable to set the desired heading or automatically adjusted in accordance with altitude to obtain correspondence between altitude and heading for traffic control purposes. Either of these conditions may be selected by the operation of a manual switch controlling electromagnetic clutches. The heading of the flight vehicle may be indicated by coloured lights controlled by rotary switches operated by the directional gyro. Altitude control.-A desired rate of climb may be automatically maintained by setting a potentiometer the output from which is applied, in opposition to the output from a potentiometer operated by a rate of climb detector, to the input of an amplifier supplying a motor operating potentiometers which apply signals to the vertical thrust controlling amplifiers in the appropriate senses. When altitude is to be automatically dependent on heading for traffic control purposes the output of a potentiometer, set to correspond to the heading desired, is substituted for the potentiometer setting rateof-climb. The flight vehicle then changes altitude until an altimeter operating a potentiometer produces a balancing signal. The potentiometer operated by the altimeter is adjustable to select the change of altitude corresponding to a given change of heading. The output of the altimeter-operated potentiometer also controls, through an amplifier and servomotor, the pick-off of the directional gyro to obtain the correspondence between altitude and heading. To compensate for the lifting effect of the surface of the flight vehicle at high speeds, a weight-spring accelerometer responsive to longitudinal acceleration operates potentiometers applying signals to the vertical thrust controlling amplifiers to reduce thrust without tending to introduce roll or pitch. Sideslip control.-The outputs of potentiometer pick-offs associated with pitot tube air speed detectors responsive to sideslip of the flight vehicle in a direction parallel to its transverse axis serve to eliminate such slip by automatically controlling, through amplifiers and servomotors, e.g. 7, 8, 9, 10, Fig. 1, the orientation of the vertical propulsion units about axes, e.g. 21, 22, 23, 24, Fig. 1, parallel to the longitudinal axis of the flight vehicle. The sensitivity of this control is automatically reduced at lower altitudes or when the flight vehicle is inclined to the roll axis, by rheostats operated in response to altidude and roll angle of the flight vehicle. Fuel supply and temperature control.-In Fig. 6 each of the five propulsion unit control systems 137, 183, 184, 185, 186 is supplied with fuel from a tank 131 by a pump 167 through a conduit 168 and is supplied with oxidizing agent from a tank 130 by a pump 133 through a conduit 134. The.propulsion units are cooled by water supplied from a condenser 179 by a pump 182 through a conduit 162, and steam generated in consequence is returned by a conduit 187 to operate a turbine 191 exhausting into condenser 179 and driving an electrical generator 193. Condenser 179 is cooled by fuel flow through conduit 208. Each propulsion unit control system, e.g. 137, comprises a fuel pressure boost pump 169 and a valve 171 which maintains constant pressure supply to fuel injector nozzle 176 by returning excess fuel through a conduit 172 to tank 131. There is also an oxidizing agent pressure boost pump 139 and a valve 141 which maintains constant pressure supply to oxidizing agent injector nozzle 148 by returning excess oxidizing agent to tank 130. A temperature-sensitive resistance 151, responsive to the temperature of the propulsion unit, controls, through a thermionic valve 190, the energization of a solenoid-operated valve 143 controlling the proportion of oxidizing agent which flows through a cooled conduit 147 on its way to in. jector nozzle 148, thus maintaining the temperature of the propulsion unit at a value determined by the setting of a rheostat 158. Thrust sharing control.-In the arrangement in which pairs of vertical propulsion units are located on the pitch and roll axes, a desired ratio is maintained between the resultant thrusts of each pair by deriving from signals produced by potentiometers adjusted by the thrust controlling servomotors, error signals which are applied through an amplifier to a servomotor adjusting potentiometers supplying correcting signals to the vertical thrust controlling amplifiers.