Electromagnetic navigation displacement transducer based on magnetic gradiometer

摘要

Electromagnetic navigation is a complementary guiding technique often used in navigation systems in conjunction with optical, GPS, and visual navigation techniques. It is especially important for smart vehicles working in severe environments and requiring high accuracy, reliability, and cost-effectiveness. In most cases, magnetic sensing arrays are assembled in the vehicles to pick up magnetic fields generated by cables buried in prescribed paths. By optimizing the position and response of the sensors in the arrays, the displacement of the vehicles to the cables can be determined and adjusted by steering systems. Though the navigation accuracy could be improved by increasing the number of sensors in the arrays, the reliability decreases with increasing the sensor number. The nonlinearity caused by discrete signals from the arrays also imposes challenges on the control systems.