Failure detection method and apparatus for sensor network

Details Failure detection method and apparatus for sensor network Failure detection method and apparatus for sensor network

2002-01-24

2004-03-30

Le, N. (Department: 2858)

Electricity: measuring and testing

Fault detecting in electric circuits and of electric components

For fault location

C324S531000

Reexamination Certificate

active

06714019

ABSTRACT:

CROSS REFERENCE TO RELATED APPLICATION
This application is based on and incorporates herein by reference Japanese Patent Application No. 2001-67315 filed Mar. 9, 2001.
FIELD OF THE INVENTION
The present invention relates to a failure detection method and apparatus for a sensor network where a plurality of pressure sensitive sensors are connected in a matrix.
BACKGROUND OF THE INVENTION
In a passenger detection sensor network for a vehicle, condition of wiring that connects each pressure sensitive sensor to an electronic control unit (ECU) needs to be monitored for a proper passenger detection operation. One proposed method for monitoring the matrix sensor network is shown in
FIG. 7. A
line
120
for monitoring row lines
100
by the ECU is connected to each row line
100
(#
1
to #
3
), and a resistor
130
is connected between each row line
100
and its corresponding line
120
. For monitoring column lines
110
(#A to #C), lines
120
and resistors
130
are connected in the same manner as rows. As a result, series circuits are constructed so that operativeness of lines
100
and
110
is monitored by feeding a test current by the ECU.
However, to detect failures (open and/or short) in a matrix circuit that contains m rows and n columns, a number of lines as many as m×2+n×2 are required even though a plurality of pressure sensitive sensors is connected in a matrix to reduce wiring.
SUMMARY OF THE INVENTION
The present invention therefore has an objective to provide a failure detection method and apparatus for a sensor network requiring less wiring for a monitoring operation.
According to the present invention, a monitoring device such as a resistor is connected to ends of two row lines or two column lines to form a series circuit with a pull-up resistor. A voltage is applied to the series circuit to check operativeness of those lines based on the voltage or current variations in the series circuit. If no failure is present in the series circuit, the divided voltage corresponding to the ratio of the pull-up resistor and a sensor resistor is developed. If the series circuit is in the shorted condition, the voltage across the monitoring device is 0V. If the series circuit is in the open condition, the voltage is equal to the voltage applied to the series circuit.


REFERENCES:
patent: 4845435 (1989-07-01), Bohan, Jr.
patent: 5635854 (1997-06-01), Shimanek et al.
patent: 5754963 (1998-05-01), Nunneley et al.
patent: 6348663 (2002-02-01), Schoos et al.
patent: 6532436 (2003-03-01), Motz
patent: 0895091 (1999-02-01), None

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