Keyless entry system

Abstract

The invention provides an access device without a key, capable of reliably judging internal and external of a vehicle even a portable machine is adjacent to a signal wire, comprising: a vehicle side device (2) and a portable machine (3). The vehicle side device (2) is mounted on the vehicle (1) and has a vehicle side sending part connected with several emission antennas (15) sending request signals via the signal wire (17) and a vehicle side receiving part receiving response signals. While the portable machine (3) has a portable receiving part which receives request signals and a portable sending part which sends response signals. The portable machine (3) is provided with a portable control part for detecting each intensity of signals sent by several emission antennas (15) of the vehicle side device (2). The vehicle side control part or the portable control part judges that the portable machine (3) is located at inner side of the vehicle when the summation of every distance calculated by two data in the intensity data from several emission antennas detected by the portable control part.

Description

technical field [0001] The present invention relates to a keyless entry device for locking and unlocking a vehicle door through wireless communication between a vehicle side device and a portable computer, and more particularly to a keyless entry device capable of accurately judging whether a portable computer is inside or outside a vehicle. key into the device. Background technique [0002] A conventional keyless entry device locks and unlocks a vehicle door through wireless communication between a vehicle-side device installed in a vehicle and a portable device carried by a user. In recent years, passive keyless entry devices have also appeared. When the portable device approaches the vehicle, the device on the vehicle side and the portable device automatically communicate with each other. As long as the ID uniquely set on each portable device is authenticated, the It can lock and unlock the door. Patent Document 1 can be cited as the above-mentioned keyless entry device...

AI Technical Summary

Problems solved by technology

Therefore, it is impossible to calculate the position of the portable machine based on each distance from multiple transmitting antennas, and it is also impossible to determine the position of the portable machine

[0006] Specifically, for example, when signals are transmitted by three transmitting antennas, combining the strength data from the three transmitting antennas can be correlated with the specific However, when the received strength is greater than expected, the distance from the strength of one transmitting antenna to the portable may sometimes fail to overlap the position of the portable determined by the signal strength from the other two transmitting antennas , and the combination of intensity data in this case becomes anomalous data

Also, the same phenomenon occurs when two transmit antennas are used

The amount of leakage from the signal wire that causes the above reasons varies depending on the vehicle, and it is difficult to achieve a balance because it mainly depends on the twisting method of the signal wire

Images