Method for calibration of a keyless entry system for a motor vehicle

• US 6,915,122 B2
• Filed: 09/13/2001
• Issued: 07/05/2005
• Est. Priority Date: 09/13/2000
• Status: Expired due to Fees

• Current Assignee: Valeo Electronique
• Original Assignee: Valeo Electronique
• Inventors: Meradi, Omar
• Primary Examiner(s): Foster, Roland G.
• Application Number:
  US09/950,806
• Publication Number:
  US 20020160720A1
• Time in Patent Office: 1,391 Days
• Field of Search: 455/91, 455/99, 455/26.1, 455/152.1, 455/296, 455/297, 455/410, 455/411, 455418-420, 455/41.2, 455/41.3, 340/426.1, 340/426.36, 343711-713, 307/10.1, 307/10.2, 180/271, 180/287
• US Class Current: 455/297
• CPC Class Codes: H01Q 1/3241 particular used in keyless entry systems

Abstract

Method for calibrating a motor vehicle hands-free access system comprising a control unit (UC) with an emitting antenna (AE) and an antenna controller (PA), consists in:

• • 1. sending to the control unit (UC), from a measurement apparatus (AM) equipped with a receiving antenna (AR) connected to the control unit (UC) via a wire link (LF), a message to configure the control unit (UC) in calibration mode,
  • 2. transmitting a signal via said emitting and receiving antennas (AE, AR) to said measurement apparatus (AM),
  • 3. measuring characteristics of the received signal, comparing them with reference values and sending calibration data via the wire link (LF),
  • 4. on receipt of the data, modifying the parameters of the antenna controller (PA). Using this method, it is possible to correct certain operating defects of the hands-free access systems through an operation at the end of the motor vehicle assembly line.

Claims

1. A method for calibrating a hands-free access system comprising an authentication and control unit mounted in a vehicle with at least one antenna that emits an electromagnetic field and an antenna controller, and a portable identification member capable of communicating from a distance with the authentication and control unit to be authenticated, which method consists in the following steps:

A. sending to the authentication and control unit, from a measurement and control apparatus equipped with an antenna for receiving an electromagnetic field, connected to the authentication and control unit via wire link, a message to configure the authentication and control unit in a calibration mode,

B. on receipt of the message, generating a signal and transmitting it from the authentication and control unit via said emitting and receiving antennas to said measurement and control apparatus,

C. measuring electromagnetic and spectral characteristics of said signal received on the receiving antenna in the measurement and control apparatus, comparing them with reference values and sending calibration data to the authentication and control unit via the wire link if the measured characteristics do not correspond to the reference values,

D. on receipt of the calibration data by the authentication and control unit, modifying the operating parameters of the antenna controller.

2. The method as claimed in claim 1 in which, in step D, the operating parameters modified are a duty cycle and/or a peak intensity in the emitting antenna and/or emission frequency values.