Measuring method for a capacitive measuring system

• US 6,707,306 B1
• Filed: 08/03/2001
• Issued: 03/16/2004
• Est. Priority Date: 02/08/1999
• Status: Expired due to Term

• Current Assignee: IEE International Electronics & Engineering SA (Aerospace Hi-Tech Holding Group Company Limited)
• Original Assignee: IEE - International Electronics & Engineering S.A.
• Inventors: Wendt, Christoph
• Primary Examiner(s): Le, N.
• Assistant Examiner(s): Benson, Walter
• Application Number:
  US09/890,686
• Time in Patent Office: 956 Days
• Field of Search: 735/141.6, 735/143.2, 324/439, 324/607, 324/662, 324/684, 324/686
• US Class Current: 324/662
• CPC Class Codes: B60R 21/01532 using electric or capacitive field sensors
• CPC Class Codes: G01B 7/287 using a plurality of fixed, simultaneously operating transducers G01B7/293 takes precedence
• CPC Class Codes: G01R 27/2605 Measuring capacitance capacitive sensors G01D5/24
• CPC Class Codes: G01V 3/088 operating with electric fields G01V3/082 takes precedence

Abstract

The capacitive coupling of at least two electrodes with an electrically conductive body may be determined when an AC voltage is applied to each of the electrodes and the currents flowing from each of the electrodes are measured. The currents flowing from each of the electrodes are measured n times, when n≧2, while different AC voltages are applied to the electrodes for each of the measurements. The coupling capacitances are calculated in a network analysis using the respective current and voltage values of the n measurements.

Claims

1. A method for determining the capacitive coupling of at least two electrodes with an electrically conductive body, said method comprising the steps of:

applying an AC voltage to each of said electrodes;

measuring the currents flowing from each of said electrodes n times, n≦

2, wherein different AC voltages are applied to said electrodes for each of said n measurements;

setting said AC voltage applied to each of said electrodes in an (i+1)-th measurement in dependence upon a result of an i-th measurement, 1≦

i≦

n−

1; and

utilizing said measured currents and voltage values of said n measurements in a network analysis to calculate said capacitive coupling.

2. The method for determining the capacitive coupling of at least two electrodes with an electrically conductive body according to claim 1, said method further comprising the steps of:

utilizing statistical methods to analyse said capacitive coupling as calaculated from said network analysis.

3. The method for determining the capacitive coupling of at least two electrodes with an electrically conductive body according to claim 1, said method further comprising the steps of:

utilizing statistical methods to analyse said capacitive coupling as calaculated from said network analysis.

4. The method for determining the capacitive coupling of at least two electrodes with an electrically conductive body according to claim 1, said method further comprising the steps of:

determining one of a shape and a position of said conductive body in dependence upon said calculated capacitive coupling.

5. The method for determining the capacitive coupling of at least two electrodes with an electrically conductive body according to claim 1, said method further comprising the steps of:

determining a position of a passenger in a vehicle in dependence upon said calculated capacitive coupling, wherein said passenger is said conductive body.