| 摘要 |
A guidance method and system for an automotive vehicle which switches from an electronic navigational signal method to a dead reckoning method when any of the field strengths of three navigational electromagnetic wave signals drops below a predetermined lower limit or vice versa when the field strengths of the three navigational electromagnetic wave signals all exceed the lower limit. Therefore, even if the navigational wave signals are obstructed by buildings or mountains, it is possible to continuously determine and display the vehicle position. The guidance system according to the present invention comprises a receive-state detection unit for detecting three field strengths and for comparing the detected field strengths with a predetermined lower limit, and a selector for selectively outputting vehicle position signals on the basis of navigational signals or dead reckoning, in addition to the conventional electronic navigation system and dead reckoning system.
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