GB746732A - Improved radio navigation simulation apparatus - Google Patents

Abstract

746,732. Trainers for radio-navigation. CURTISS-WRIGHT CORPORATION. July 26, 1954, No. 21789/54. Class 40 (7). A radio navigation trainer comprises means providing quantities representing the co-ordinates of the instant position of the craft, means providing quantities representing the position of a radio beacon, means adjustable to provide quantities representative of the position of the craft destination relative to the beacon, and combining means for combining all the quantities to obtain control quantities representing the co-ordinates of the craft position relative to the destination. The trainer is completed by a resolver deriving from these control quantities and height and/or compass bearing as required one or more of the quantities: bearing of destination from craft, distance to destination from craft, slant distance to destination from craft, and deviation of craft from course to destination. The movement of the craft may be simulated by signals set up by an " air-speed indicator " 1 and " compass " 2. These are combined in x and y co-ordinate amplifiers 15 and 17 with signals derived to represent the components of wind velocity and direction set in respectively at 18 and 19. Amplifiers 15 and 17 each drive motor and generator integration devices having feed-back paths indicated respectively at 36<SP>1</SP> and 461. The instantaneous rest position of the motorgenerator shafts determines the potentials derived from potentiometers 38 and 48 which after amplification at 52 and 51 are the quantities representing the instant craft position. The distance (R) and bearing (#) of the destination from the beacon are set in respectively at 57 and 58 and are utilized to provide rectangular co-ordinate difference quantities fed out over lines 65<SP>1</SP> and 66<SP>1</SP>. The co-ordinates of the beacon station are set in by controls 68 and 69 and the quantities derived from the corresponding potentiometers fed out over lines 70<SP>1</SP> and 71<SP>1</SP>. All the quantities relating to the X direction co-ordinates are combined in amplifier 54 to give a quantity corresponding to the x co-ordinate of the craft relative to its destination, similarly all the Y direction coordinates are combined in amplifier 56 to give the corresponding y co-ordinate quantity. These quantities are fed out at 74 and 75 and into rotary transformer 76 (Fig. 1B), which is the first part of the resolver. The orthogonallyplaced rotatable windings 79 and 80 are part of the bearing servo loop. They are maintained in a position representing the bearing of the craft with respect to the destination by the operation of amplifier 82, motor amplifier 86, and servomotor 92 mechanically coupled to the windings. The amplifier 82 is arranged to have a gain K/D where D is the distance to the destination, thus providing sensitive opertion close to the destination. In addition a phase-sensitive rectifier 84 is provided fed from winding 79 which operates relay 87, 88 to " kick " the servo over to the correct bearing when the craft passes over the destination position. The resolver 95 is energized in accordance with the positioning of simulated compass 94 which may be coupled to " compass " 2, its rotor 100 is coupled to the bearing servomotor. The resolver 95 feeds receiver 101 which positions indicator 105 in accordance with the difference between the destination bearing and the craft heading. Winding 79 of transformer 76 is also coupled to one stator winding 111 of rotary transformer 109, the other stator winding being energized in accordance with altitude input at 106. A servo loop including one rotor winding 112 and motor 118 serve to position the rotor in accordance with the slant distance and an output proportional to this is fed from winding 113 to a positioning arrangement by means of which indicator 128 is set to indicate slant range. A pilo's course selector 129 sets rotary transformer 130 which feeds resolver 134 whose rotor is positioned by the bearing servomotor 92. The outputs from the resolver rotor are used to control left-right indicator 148 and " to-from " ambiguity indicator 145. Transformer 130 also feeds resolver 149 by means of which is controlled the instructor's indicator 158 which indicates to the instructor the course selected by the pilot. Specifications 693,821 and 693,890 are referred to.