Title:
METHOD FOR MEASURING DISTANCE BETWEEN TWO OBJECTS AND METHOD FOR CONTROLLING ACCESS TO AN OBJECT OR THE USE THEREOF, IN PARTICULAR ACCESS CONTROL AND DRIVING AUTHORISATION FOR A MOTOR VEHICLE
Document Type and Number:
WIPO Patent Application WO2002001247
Kind Code:
A3
Abstract:
A bi-directional dialogue is carried out between a portable code emitter (15) and a base station (1) for access to a motor vehicle. Both signals are correlated with each other and the dialogue repeated at an altered carrier frequency. The distance of the code emitter (15) from the base station (11) is determined from the difference in two phase difference measurements between the sent and received signal in one station (11 or 15). Access to, or use of the motor vehicle (10) is only permitted when the code emitter (15) is within a certain distance from the motor vehicle (10).
Inventors:
BERGERHOFF NIKOLAS (DE)
Application Number:
PCT/EP2001/006784
Publication Date:
March 28, 2002
Filing Date:
June 15, 2001
Export Citation:
Assignee:
SIEMENS AG (DE)
BERGERHOFF NIKOLAS (DE)
BERGERHOFF NIKOLAS (DE)
International Classes:
B60R25/20; B60R25/24; E05B49/00; G01S7/40; G01S13/84; G07C9/00; (IPC1-7): G01S13/84; E05B49/00; G01S7/40
Foreign References:
| US4757315A | 1988-07-12 | |||
| US5723911A | 1998-03-03 |
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