GB411124A - Improvements in or relating to a method and apparatus for determining the position of travelling ships and aircraft - Google Patents

Abstract

411,124. Measuring speed of and distance travelled by moving bodies; integrating apparatus; course-recording apparatus; supply meters. RADIOAKT.- GES. D. S. LOEWE, 10, Wiesenweg, Steglitz, Berlin. Aug. 29, 1932, No. 24058. Convention date, Sept. 5, 1931. [Classes 106 (iii) and 106 (iv).] The distance travelled by a ship or an aircraft is measured by a double time integration of the accelerations acting on the ship or aircraft utilizing the piezoelectric effect. The accelerations of the aircraft act on the mass 15 to produce piezo-electric effects on the quartz members 1, either through a lever transmission system or directly, which through the amplifier valves 2, 3, 4 and 5 produce fluctuations in the potentials at the resistances 6 and 7 which are applied through the electrodes 11 and 12 to the electro-osmotic cell 8. The device 1, 15 is maintained in an invariable direction by means of a magnetic or gyroscopic compass. The cell 8 comprises a porous cylinder 9 situated in and containing a conducting liquid, e.g. dilute potassium nitrate, and connected with a U-tube 10 containing mercury which is displaced by the inflowing or outflowing conducting liquid by an amount which is a measure of the first time integral of the acceleration acting on the mass m, i.e. a measure of the speed component of the aircraft. The column of mercury is displaced along a resistance 13 in circuit with a battery and a quantity of electricity meter 14, the indications of which are thus a measure of the second time integral of the acceleration, i.e. the route component of the aircraft. Fig. 2 shows a modified form of osmotic cell in which the resistances 6 and 7 are replaced by the resistances of two osmotic cells 16, 17, the horizontal column of mercury 18 moving along the resistance wire 19. For determining the horizontal route components, the vertical route component being obtained by other means, the arrangement shown in Fig. 3 is used. The mass m is supported laterally by four quartz members 1 held in a fork-like frame 23 mounted in a cardanic suspension, the whole device being maintained in an invariable direction by means of a magnetic or gyroscopic compass. The rod 24 of the fork carries a mass m<1> acting as a pendulum. In the arrangement shown in Fig. 4 the mass m and quartz crystals 1 are fitted in a cardanic suspension and furnished with a gyroscopic pendulum at right angles to the plane of the paper, the whole system being rotated by a drive around the centre axis of the pendulum. An alternating potential will thus be produced at the terminals 27, and a second alternating potential is produced at the terminals 28 by two coils 33 and 34 rotating between two magnets 25 and 26 maintained in a constant direction by means of a magnetic or gyroscopic compass. The amplified piezo-electric current from the terminals 27 is fed to one coil of a watt-hour meter and the current from the terminals 28 to the other coil, the indication of the meter bemg proportional to the speed component of the aircraft in the North-South direction. The meter can, by means of a rheostat, regulate the strength of a direct current to be proportional to its indiction, the time integral of this current, obtained by an electric quantity meter, giving the route-component of the aircraft in the North-South direction. A wattless-component meter is used to obtain the East-West component.