| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a keyless system capable of performing vicinity area determination and vehicular inside and outside area determination at lower cost without requiring a number of vehicular inside antennas and vehicular outside antennas. <P>SOLUTION: An on-vehicle machine is equipped with a first antenna for radiating radio waves, a speaker for emitting acoustic waves, and a control section for calculating a distance between a vehicle and a user. A portable machine is equipped with a second antenna for receiving a radio wave radiated by the first antenna, and a microphone for receiving an acoustic wave emitted by the speaker. The control section of the on-vehicle machine calculates the distance between the vehicle and the user on the basis of a radio wave reception time at which the second antenna receives the radio wave radiated by the first antenna and an acoustic wave reception time at which the microphone receives the acoustic wave emitted by the speaker. It is determined whether the portable machine exists in a vehicular inside, in a vicinity area outside the vehicle, or in an area distant from the vehicle on the basis of the calculated distance between the vehicle and the user. A keyless system is constituted in such a way, thus the number of required components can be reduced. <P>COPYRIGHT: (C)2013,JPO&INPIT |
