Title:
伝搬時間測定システム及びそのシステムを動作する方法
Document Type and Number:
Japanese Patent JP2007532369
Kind Code:
A
Abstract:
A time-of-flight ranging system, such as a keyless entry system, comprises a first part (10) and a second part (12) which may implemented as a portable device such as a key fob. Both parts have signal transmitting and receiving means (14, 22 and 26, 32) for effecting communication with each other. The signal transmitting and receiving means introduce non-predictable time delays in their respective internal signal propagation paths. The first part includes a controller (18) for determining the time-of-flight of the signals io between the parts. In order to allow for the non-predictable time delays, the first and second parts are located within a known distance of each other and the time-of flight over the known distance is measured, the time difference between the measured time-of-flight and a theoretical time-of-flight over the known distance is determined and is used to adjust the measured time-of-flight is and thereby the range. The time-of-flight ranging system may be applied to not only entry security systems but also to tracking systems such as systems for tracking toddlers, personnel and equipment.
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Inventors:
Reach, Adam S
Dooley, Soul Earl
Dooley, Soul Earl
Application Number:
JP2007501413A
Publication Date:
November 15, 2007
Filing Date:
February 25, 2005
Export Citation:
Assignee:
Koninklijke Philips Electronics N.V.
International Classes:
B60R25/24; G01S13/74; G07C9/00; H04B1/59; H04B7/26; H04W24/00; H04W84/10
Attorney, Agent or Firm:
Tadahiko Ito
Shinsuke Onuki
Tadashige Ito
Watanabe Naomitsu
Shinsuke Onuki
Tadashige Ito
Watanabe Naomitsu