| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a keyless entry device capable of easily determining a position of a portable machine, by maximally approaching a boundary surface for discriminating the position of the portable machine, to a shape of a car body. <P>SOLUTION: A vehicle side device 2 has a vehicle side control part 12 for performing predetermined control when authenticating an answer signal from the portable machine 3. The portable machine 3 has a portable machine control part 22 detecting respective strengths of signals transmitted from a plurality of transmission antennas of the vehicle side device 2. The vehicle side control part 12 and the portable machine control part 22 respectively calculate a distance between the portable machine 3 and the transmission antennas 15 on the signal strengths from the plurality of transmission antennas 15 detected by the portable machine 3, and calculate two distances among the calculated distance or a total distance of adding a numeric value of multiplying the two distances by a predetermined factor, and determine in which of the inside and outside of a predetermined boundary surface 30 the portable machine 3 is positioned by comparing the total distance with a predetermined threshold value. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
