Automatic dead reckoning navigator and steering aid - uses magnetometer and A=D converter circuit connected to speed-distance recorder

摘要

The dead-reckoning navigator is designed to provide dead-reckoning information for any curved track automatically. A twin-axis magnetometer (2) is suspended in a gimbal (1) and produces two analogue signals (1, q) which are proportional to the projections of the Earth's magnetic field on the vehicle's longitudinal or transverse axis. Pulses from a speed/distance recorder (3) are fed with those from the magnetometer to a dual-slope type A/D converter (5). Three counters sum the separate components (6). The variation in the magnetic field is corrected for (4) and a reference signal produced. The magnetometer is fitted with adjusters to compensate for inherent and induced stray fields. An auxiliary unit gives the vehicle speed and course deviation.