Data processing: vehicles – navigation – and relative location – Vehicle control – guidance – operation – or indication – Vehicle diagnosis or maintenance indication
Reexamination Certificate
2003-02-25
2004-01-20
Black, Thomas G. (Department: 3663)
Data processing: vehicles, navigation, and relative location
Vehicle control, guidance, operation, or indication
Vehicle diagnosis or maintenance indication
C701S031000, C701S045000, C180S282000
Reexamination Certificate
active
06681162
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a corrective device for an output of an acceleration sensor that corrects an offset of the output of the acceleration sensor to a zero point and a method of correcting the output thereof.
2. Description of the Related Art
FIG. 9
is a block diagram showing a circuit configuration of the conventional corrective device for an output of the acceleration sensor disclosed in Published Unexamined Japanese Patent Application No. 5-45373.
Referring to
FIG. 9
, reference numeral
21
denotes a bridge of the acceleration sensor,
22
denotes an operational amplifier,
23
denotes an operational amplifier,
24
denotes a capacitor,
25
denotes a feedback resistor, each of them is a constituent of a low-pass filter. This circuit is arranged such that a time constant (T=CR) of the low-pass filter is determined by the capacitor
24
and the feedback resistor
25
, and that a signal having a frequency higher than that determined on the basis of the time constant is to be attenuated. The operational amplifier
23
outputs a signal whose component is close to a direct-current component, i.e. an offset component. The output of the operational amplifier
23
is inputted to a non-inverted input terminal
26
of the operational amplifier
22
, and a difference between the signal inputted to the non-inverted input terminal
26
and a signal inputted to an inverted input terminal
27
from the acceleration sensor, i.e. a corrected signal whose offset component has been removed appears at an output terminal
28
of the low-pass filter.
However, the conventional corrective device for an output of the acceleration sensor is configured by the hardware made up of circuitries, such as the operational amplifiers
22
,
23
, the capacitor
24
, and the feedback resistor
25
. Therefore, the device suffers from a great change in the time constant due to dispersion of parts and is subject to restriction on the corrective ability attributable to limitations put on the parts (resistance value, capacitance value). Moreover, the hardware filter of this kind is likely to be affected by temperature and noises, and thus it is apt to lower the corrective ability due to deterioration of the parts.
SUMMARY OF THE INVENTION
The present invention has been made to solve the above problems and an object thereof is to provide a corrective device for an output of an acceleration sensor realizing an offset correction with accuracy by operation means on the software basis.
A corrective device for an output of an acceleration sensor according to the present invention includes operation processing means in control means for inputting a self-diagnosis check signal to an acceleration sensor, and executing an offset corrective operation processing of the output of the acceleration sensor prior to inputting the self-diagnosis check signal to the acceleration sensor.
According to the present invention, since the operation processing means inputs the self-diagnosis check signal to the acceleration sensor and executes an offset corrective operation processing of the output of the acceleration sensor prior to inputting the self-diagnosis check signal to the acceleration sensor, output variations due to the self-diagnosis check of the acceleration sensor are prevented from being taken in to the operation processing means. This enhances accuracy of a corrective operation processing and shortens a response time of the correction.
A method of correcting an output of an acceleration sensor according to the present invention, includes the steps of inputting a self-diagnosis check signal to the acceleration sensor by operation processing means in control means, and executing an offset corrective operation processing of an output of the acceleration sensor prior to inputting the self-diagnosis check signal to the acceleration sensor.
According to the present invention, since the method of correcting the output of the acceleration sensor includes the steps of inputting a self-diagnosis check signal to the acceleration sensor by the operation processing means in the control means, and executing an offset corrective operation processing of the output of the acceleration sensor prior to inputting the self-diagnosis check signal to the acceleration sensor, no influence is excised by the output variations due to the self-diagnosis check of the acceleration sensor. This enhances accuracy of the corrective operation and shortens a response time of the correction.
The above and other objects and the attendant advantages of the invention will become readily apparent by referring to the following detailed description when considered in conjunction with the accompanying drawings, wherein:
REFERENCES:
patent: 5081442 (1992-01-01), Ito et al.
patent: 5673932 (1997-10-01), Nitschke et al.
patent: 5897599 (1999-04-01), Takeuchi
patent: 6308554 (2001-10-01), Mattes et al.
patent: 6360147 (2002-03-01), Lee
patent: 6470249 (2002-10-01), Schmid et al.
patent: 5-23139 (1993-03-01), None
patent: 07-159438 (1995-06-01), None
patent: 2812007 (1998-08-01), None
Black Thomas G.
Mancho Ronnie
LandOfFree
Corrective device for output of acceleration sensor and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Corrective device for output of acceleration sensor and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Corrective device for output of acceleration sensor and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3186619