Title of Invention

A CONTROL SYSTEM AND MEHTOD FOR PROCESSING A SENSOR SIGNAL FOR A VEHICLE

Abstract The invention relates to a control system for a vehicle (10) characterized by comprising: a signal processing module (40) that receives a sensor signal (28) from an engine knock sensor (26) and extracts a plurality of sample points (50,52,56) from the sensor signal (28); a computation module (42,44,46,48) that computes a summation of the sample points (52), that computes a summation of squares (54) of the sample points (56) and that computes a standard deviation (60) based on the summation of the sample points (50,52,56) and the summation of the squares (54) of the sample points (50,52,56); and a control module (34) that generates a control signal (38) that controls combustion in an engine (13) based on the sensor signal (28) and the standard deviation (60).
Full Text

FIELD OF THE INVENTION
The present disclosure relates to methods and systems for processing digital
signals in a vehicle control system.
BACKGROUND OF THE INVENTION
The statements in this section merely provide background information related to
the present disclosure and may not constitute prior art.
Vehicles include an internal combustion engine that generates drive torque. More
specifically, the engine draws in air and mixes the air with fuel to form a
combustion mixture. The combustion mixture is compressed and ignited to drive
pistons that are disposed within the cylinders. The pistons rotatably drive a
crankshaft that transfers drive torque to a transmission and wheels. A knock
sensor generates a knock signal based on a vibration of the engine. Disturbances
in the knock signal, such as from background noise, can cause inaccurate engine
knock determinations and, therefore, may cause one or more vehicle subsystems
to operate inefficiently.
Conventional methods of processing the knock signal for background noise
include moving averages methods, first order lag filters, and a full standard
deviation computation. The use of a full standard deviation computation method
provides superior description of the sample distribution to the moving averages
methods and the first order lag filters. A commonly known equation for the full
standard deviation includes:


Where d1 is a sample point, d is the average of the sample points, and N
represents the number of sample points. This full standard deviation computation
method requires a buffering for every point that is part of the distribution or
alternatively using highly throughput-intensive data manipulation in order to
produce an average and standard deviation. Thus, to achieve superior signal
processing, large amounts of controller memory and throughput must be added.
Increased processor throughput and additional memory can be costly to the
controller.
SUMMARY OF THE INVENTION
Accordingly, a control system for a vehicle is provided. The control system
includes a signal processing module that receives a sensor signal and extracts a
plurality of sample points from the sensor signal. A computation module
computes a summation of the sample points, computes a summation of squares
of the sample points, and computes a standard deviation based on the
summation of the sample points and the summation of the squares of the
sample points. A control module generates a control signal based on the sensor
signal and the standard deviation.

In other features, a method of processing a sensor signal for a vehicle is
provided. The method includes: processing a plurality of sample points from a
sensor signal; computing a summation of the sample points; computing a
summation of squares of the sample points; computing a standard deviation
based on the summation of the sample points and the summation of the squares
of the sample points; and generating a control signal based on the sensor signal
and the standard deviation.
Further areas of applicability will become apparent from the description provided
herein. It should be understood that the description and specific examples are
intended for purposes of illustration only and are not intended to limit the scope
of the present disclosure.
BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
The drawings described herein are for illustration purposes only and are not
intended to limit the scope of the present disclosure in any way.
Figure 1 is a functional block diagram illustrating a vehicle including an engine
system.
Figure 2 is a dataflow diagram illustrating digital signal processing system in
accordance with various aspects of the present teachings.
FIG. 3 is a flowchart illustrating a digital signal processing method in accordance
with various aspects of the present teachings.

DETAILED DESCRIPTION OF THE INVENTION
The following description is merely exemplary in nature and is not intended to
limit the present disclosure, application, or uses. It should be understood that
throughout the drawings, corresponding reference numerals indicate like or
corresponding parts and features. As used herein, the term module refers to an
application specific integrated circuit (ASIC), an electronic circuit, a processor
(shared, dedicated, or group) and memory that executes one or more software
or firmware programs, a combinational logic circuit, and/or other suitable
components that provide the described functionality.
Referring now to FIG. 1, a vehicle 10 includes various electronically-controlled
systems. For example, an engine system 12 includes an engine 13 that combusts
an air and fuel mixture to produce drive torque. Air is drawn into an intake
manifold 14 through a throttle 16. The throttle 16 regulates mass air flow into
the intake manifold 14, Air within the intake manifold 14 is distributed into
cylinders 18. Although four cylinders 18 are illustrated, it can be appreciated that
the engine 13 can have a plurality of cylinders 18, including, but not limited to,
2, 3, 5, 6, 8, 10, 12, and 16 cylinders. It is also appreciated that the engine 13
may, in the alternative, include a V-type cylinder configuration.

The air within the cylinders 18 is mixed with fuel and combusted therein. The
combustion process drives a crankshaft (not shown) to produce drive torque.
Combustion exhaust within the cylinders 18 is forced out through an exhaust
manifold 20. The combustion exhaust is treated in an exhaust system (not
shown). The engine system 12 includes various sensors that generate digital
signals based on sensed information from the engine system 12. For example, an
engine speed sensor 22 generates a digital engine speed signal 24 based on a
rotational speed of the crankshaft. A knock sensor 26 generates a digital knock
signal 28 indicating a vibration of the engine 13. A temperature sensor 30
generates a digital temperature signal 32 indicating a temperature of air entering
the engine 13. As can be appreciated, the engine system 12 can include various
other digital sensors. Hereinafter, one or more of the sensors discussed above
will be commonly referred to as a digital sensor 36 that generates a digital signal
38.
A control module 34 receives one or more of the digital signals 38 from the
digital sensors 36 of the engine system 12 and processes the digital signals 38
based on digital signal processing methods of the present disclosure. More
particularly, the control module 34 computes a partial standard deviation for
background noise picked up by the digital sensor 36 and generated in the digital
signal 38. The partial standard deviation is then used to differentiate between
normal noise and unwanted operation condition events. Based on the
differentiation, the control module 34 can more efficiently interpret the digital
signal 38 and control one or more components of the engine system 12.
Similarly, the digital signal processing systems and methods of the present
disclosure can apply to other electronically-controlled systems in the vehicle 10

that include digital sensors 36, such as, but not limited, a transmission system, a
body system, and a throttle system. For ease of the discussion, the disclosure
will be discussed in the context of an engine system 12.
Referring now to FIG. 2, a dataflow diagram illustrates various embodiments of a
digital signal processing system that may be embedded within the control
module 34. Various embodiments of digital signal processing systems according
to the present disclosure may include any number of sub-modules embedded
within the control module 34. As can be appreciated, the sub-modules shown
may be combined and/or further partitioned to similarly process the digital signal
38. Inputs to the system may be sensed from the vehicle 10 (Figure 1), received
from other control modules (not shown) within the vehicle 10 (Figure 1), and/or
determined by other sub-modules (not shown) within the control module 34. In
various embodiments, the control module 34 of Figure 2 includes a signal
processing module 40, a first summation module 42, a second summation
module 44, a subtraction module 46, and a square-root module 48.
The signal processing module 40 receives as input the digital signal 38. The
signal processing module 40 extracts a number 50 of sample points 52 from the
digital signal 38. A first summation module 42 receives as input the sample
points 52. The first summation module 42 computes a square of each sample
point 52 and a summation of the squares 54 of each sample point 52. A second
summation module 44 receives as input the number 50 and the sample points

52. The second summation module 44 computes a summation of points 56 by
computing a summation of the sample points 52, computing a square of the
summation, and dividing the square by the number 50 of points.
The subtraction module 46 receives as input the sum of squares 54 and the sum
of points 56. The subtraction module 46 computes a difference 58 between the
sum of squares 54 and the sum of points 56. The square-root module 48
receives as input the difference 58. The square-root module 48 computes a
partial standard deviation 60 by computing a quotient by dividing the difference
by the number 50 of points minus one, and taking a square root of the quotient.
The partial standard deviation 60 can then be used to calculate a signal-to-noise
ratio. The signal-to-noise ratio is then used to process the digital signal 38 for
controlling one or more components of the engine system 12 (Figure 1).
Referring now to Figure 3, a flowchart illustrates various embodiments of a
digital signal processing method that may be performed by the digital signal
processing system of Figure 2. In various embodiments, the digital signal
processing method is scheduled to run periodically during vehicle operation. As
can be appreciated, the digital signal processing method of the present
disclosure is not limited to the sequential execution as shown in Figure 3. In one
example, the method may begin at 100. A presence of the digital signal 38
(Figure 2) is evaluated at 110. If a digital signal 38 (Figure 2) is received at 110,
a number N of sample points d1 are extracted from the digital signal 38 at 120.

Otherwise, the method continues to monitor for the presence of the digital signal
38 at 110.
Once the number N of sample points d1 are extracted from the digital signal 38
at 120, the partial standard deviation 60 is computed at 130. In various
embodiments, the partial standard deviation 60 is computed based on the
following equation:

The digital signal 38 can then be processed based on the partial standard
deviation 60 to determine the actual signal-to-noise ratio at 140. Based on the
signal-to-noise ratio and the digital signal 38, one or more components of the
engine system 12 (Figure 1) are controlled at 150. The method may end at 160.
Those skilled in the art can now appreciate from the foregoing description that
the broad teachings of the present disclosure can be implemented in a variety of
forms. Therefore, while this disclosure has been described in connection with

particular examples thereof, the true scope of the disclosure should not be so
limited since other modifications will become apparent to the skilled practitioner
upon a study of the drawings, specification, and the following claims.

We Claim:
1. A control system for a vehicle (10), comprising:
a signal processing module (40) that receives a sensor signal (28) from an
engine knock sensor (26) and extracts a plurality of sample points (50,52,56)
from the sensor signal (28);
a computation module (42,44,46,48) that computes a summation of the sample
points (52), that computes a summation of squares (54) of the sample points
(56), and that computes a standard deviation (60) based on the summation of
the sample points (50,52,56) and the summation of the squares (54) of the
sample points (50,52,56); and
a control module (34) that generates a control signal (38) that controls
combustion in an engine (13) based on the sensor signal (28) and the standard
deviation (60).
2. The control system as claimed in claim 1 wherein the computation module
computes the standard deviation based on a difference between the summation
of the squares of the sample points and the summation of the sample points.
3. The control system as claimed in claim 2 wherein the computation module
computes the standard deviation by dividing the difference by one less than a
number of the sample points.
4. The control system as claimed in claim 3 wherein the computation module
computes the standard deviation by computing a square root of a result of the
dividing the difference by one less than the number of the sample points.
5. The control system as claimed in claim 1 wherein the computation module
computes the summation of the sample points, computes a square of the
summation of the sample points, and computes a quotient by dividing the square
of the summation of the sample points by a number of the sample points, and
wherein the standard deviation is computed based on the quotient.

6. The control system as claimed in claim 1 wherein the control module
computes a sensor signal-to-noise ratio based on the standard deviation and
generates a control signal based on the sensor signal and the sensor signal-to-
noise ratio.
7. The control system as claimed in claim 1 wherein the control signal controls a
transmission system based on the sensor signal and the standard deviation.
8. A method of processing a sensor signal for a vehicle, comprising:
generating a sensor signal using an engine knock sensor;
processing a plurality of sample points from the sensor signal;
computing a summation of the sample points;
computing a summation of squares of the sample points;
computing a standard deviation based on the summation of the sample points
and the summation of the squares of the sample points; and
generating a control signal that controls combustion in an engine based on the
sensor signal and the standard deviation.
9. The method as claimed in claim 8 comprising:
computing a square of the summation of the sample points; and
computing a quotient by dividing the square by a number of the sample points,
wherein the standard deviation is computed based on the quotient.
10. The method as claimed in claim 8 wherein the computing the standard
deviation comprises computing the standard deviation based on a difference
between the summation of the squares of the sample points and the summation
of the sample points.

11. The method as claimed in claim 10 wherein the computing the standard
deviation further comprises computing the standard deviation by dividing the
difference by one less than a number of the sample points.
12. The method as claimed in claim 11 wherein the computing the standard
deviation further comprises computing the standard deviation by computing a
square root of a result of the dividing the difference by one less than the number
of the sample points.
13. The method as claimed in claim 8 comprising computing a sensor signal-to-
noise ratio based on the standard deviation and wherein the generating the
control signal is based on the sensor signal-to-noise ratio.
14. The method as claimed in claim 8 comprising controlling a transmission
system based on the sensor signal and the standard deviation.



ABSTRACT


TITLE "A CONTROL SYSTEM AND METHOD FOR
PROCESSING A SENSOR SIGNAL FOR A VEHICLE"
The invention relates to a control system for a vehicle (10) characterized
by comprising: a signal processing module (40) that receives a sensor
signal (28) from an engine knock sensor (26) and extracts a plurality of
sample points (50,52,56) from the sensor signal (28); a computation
module (42,44,46,48) that computes a summation of the sample points
(52), that computes a summation of squares (54) of the sample points
(56) and that computes a standard deviation (60) based on the
summation of the sample points (50,52,56) and the summation of the
squares (54) of the sample points (50,52,56); and a control module (34)
that generates a control signal (38) that controls combustion in an engine
(13) based on the sensor signal (28) and the standard deviation (60).

Documents:

00302-kol-2008-abstract.pdf

00302-kol-2008-claims.pdf

00302-kol-2008-correspondence others.pdf

00302-kol-2008-description complete.pdf

00302-kol-2008-drawings.pdf

00302-kol-2008-form 1.pdf

00302-kol-2008-form 2.pdf

00302-kol-2008-form 3.pdf

00302-kol-2008-form 5.pdf

302-KOL-08-CORRESPONDENCE OTHERS 1.1.pdf

302-KOL-08-PRIORITY DOCUMENT.pdf

302-KOL-2008-(26-08-2013)-ABSTRACT.pdf

302-KOL-2008-(26-08-2013)-ANNEXURE TO FORM 3.pdf

302-KOL-2008-(26-08-2013)-CLAIMS.pdf

302-KOL-2008-(26-08-2013)-CORRESPONDENCE.pdf

302-KOL-2008-(26-08-2013)-DESCRIPTION (COMPLETE).pdf

302-KOL-2008-(26-08-2013)-DRAWINGS.pdf

302-KOL-2008-(26-08-2013)-FORM-1.pdf

302-KOL-2008-(26-08-2013)-FORM-2.pdf

302-KOL-2008-(31-10-2012)-PETITION UNDER RULE 137.pdf

302-KOL-2008-(31-10-2012-RI)-ABSTRACT-1.pdf

302-KOL-2008-(31-10-2012-RI)-ABSTRACT.pdf

302-KOL-2008-(31-10-2012-RI)-ANNEXURE TO FORM 3-1.pdf

302-KOL-2008-(31-10-2012-RI)-ANNEXURE TO FORM 3.pdf

302-KOL-2008-(31-10-2012-RI)-CLAIMS-1.pdf

302-KOL-2008-(31-10-2012-RI)-CLAIMS.pdf

302-KOL-2008-(31-10-2012-RI)-CORRESPONDENCE-1.pdf

302-KOL-2008-(31-10-2012-RI)-CORRESPONDENCE.pdf

302-KOL-2008-(31-10-2012-RI)-DESCRIPTION (COMPLETE)-1.pdf

302-KOL-2008-(31-10-2012-RI)-DESCRIPTION (COMPLETE).pdf

302-KOL-2008-(31-10-2012-RI)-DRAWINGS-1.pdf

302-KOL-2008-(31-10-2012-RI)-DRAWINGS.pdf

302-KOL-2008-(31-10-2012-RI)-FORM-1-1.pdf

302-KOL-2008-(31-10-2012-RI)-FORM-2-1.pdf

302-KOL-2008-(31-10-2012-RI)-FORM-2.pdf

302-KOL-2008-(31-10-2012-RI)-FORM-5-1.pdf

302-KOL-2008-(31-10-2012-RI)-FORM-5.pdf

302-KOL-2008-(31-10-2012-RI)-OTHERS-1.pdf

302-KOL-2008-(31-10-2012-RI)-OTHERS.pdf

302-KOL-2008-(31-10-2012-RI)-PA-1.pdf

302-KOL-2008-(31-10-2012-RI)-PA.pdf

302-KOL-2008-ASSIGNMENT.pdf

302-KOL-2008-CANCELLED PAGES.pdf

302-KOL-2008-CORRESPONDENCE OTHERS 1.1.pdf

302-KOL-2008-DECISION.pdf

302-KOL-2008-EXAMINATION REPORT.pdf

302-kol-2008-form 18.pdf

302-KOL-2008-GPA.pdf

302-KOL-2008-GRANTED-ABSTRACT.pdf

302-KOL-2008-GRANTED-CLAIMS.pdf

302-KOL-2008-GRANTED-DESCRIPTION (COMPLETE).pdf

302-KOL-2008-GRANTED-DRAWINGS.pdf

302-KOL-2008-GRANTED-FORM 1.pdf

302-KOL-2008-GRANTED-FORM 2.pdf

302-KOL-2008-GRANTED-FORM 3.pdf

302-KOL-2008-GRANTED-FORM 5.pdf

302-KOL-2008-GRANTED-SPECIFICATION-COMPLETE.pdf

302-KOL-2008-OTHERS.pdf

302-KOL-2008-PETITION UNDER RULE 137.pdf

302-KOL-2008-REPLY TO EXAMINATION REPORT.pdf

302-KOL-2008-TRANSLATED COPY OF PRIORITY DOCUMENT.pdf

abstract-00302-kol-2008.jpg


Patent Number 260474
Indian Patent Application Number 302/KOL/2008
PG Journal Number 18/2014
Publication Date 02-May-2014
Grant Date 30-Apr-2014
Date of Filing 19-Feb-2008
Name of Patentee GM GLOBAL TECHNOLOGY OPERATIONS, INC.
Applicant Address 300 GM RENAISSANCE CENTER DETROIT, MICHIGAN 48265-3000
Inventors:
# Inventor's Name Inventor's Address
1 WAJDI B. HAMAMA 10984 EAST CHARRING CROSS CIRCLE WHITMORE LANE, MICHIGAN 48189
2 JOHN F. VAN GILDER 4214 MORRICE ROAD, WEBBERVILLE, MICHIGAN- 48892
PCT International Classification Number G06F12/06; G06F9/318; G06F12/06
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 11/717,802 2007-03-13 U.S.A.