Measuring orientation of moving object, esp. vehicle - using geomagnetic directional sensor to measure horizontal components of earths magnetic field, and compsn. for magnetisation changes

摘要

Both horizontal components of the Earth's magnetic field are measured by a geomagentic directional sensor mounted in the moving object. The orientation of the object is derived from the direction of a vector in the coordinate plane between the centre of the circle locus of all the measurement value pairs and the actual pair. The sensor signal is used to decide whether the measurement result is affected by a change in the state of magnetisation of the object. Parameters are computed giving the direction and magnitude of the deviation of the measurement result and the position of the centre of the measurement value circle before the change in magnetisation. The magnetisation is determined and used to derive the new coordinates of the centre of the measurement circle. USE/ADVANTAGE - For measuring forward direction of object, esp. vehicle. Does not require object to be rotated through large angle.