| 摘要 |
<p>The position of a vehicle is to be detected accurately while suppressing the consumption of a battery. In accordance with instructions given from a position detection service center a base station issues requests at certain intervals. A vehicle V, upon receipt of a request, issues an answer signal containing ID information. On the basis of the answer signal the position detection service center decides the position of the vehicle V and offers the position information to a control center on demand. Electric power is supplied from a vehicular battery to an answer signal issuing member installed in the vehicle V. Even after a main power supply switch is turned OFF, the supply of electric power from the battery is continued, thus permitting an answer to a request from the base station. Consequently, the control center can determine a vehicular stop position accurately.</p> |
