COMMISSIONER'S DECISION
Computer Program - The correcting signal obtained by the arrangement of means
in a process control system was found to be directed to more than an algorithm.
All claims found not to define the arrangement. Rejection modified.
************************
This decision deals with Applicant's request that the Commissioner of Patents
review the Examiner's Final Action on application 287,623 (Class 341-110). The
application was filed September 27, 1977, and is entitled GAIN ADAPTIVE PROCESS
CONTROL. The inventors are Thomas M. Bartley and Richard F. Giles. The
Examiner in charge issued a Final Action on April 21, 1981 refusing the
application.
The application relates to a method and apparatus used in a process control
system such as in electrical analog, digital electronic, pneumatic, mechanical,
hydraulic and other control system formats. Such a system is shown in figure 1
of the application, reproduced below. Controller 11 receives an input signal
12 and a variable signal 14. The controller has a comparison means 15 and a
controller characteristic means 17 which act on signals 12 and 14 to produce a
process control signal 18, which in turn is sent both to the actual process 21,
and to the process simulator means 31. Signal 27 which is actually produced by
the process, and signal 37 from the simulator, are led to the divider means 41.
Here a ratio signal 42 is obtained and sent to a multiplier means 43. This
means performs a multiplying action on both the ratio signal and the process
prediction signal 33 to produce the variable signal 14. Controller 11 uses the
variable signal to control the process in an on-going manner in response to
process variations from desired conditions.
(See formula 1)
In the Final Action the Examiner said that the disclosure and claims are
essentially directed to an algorithm for controlling a process and are therefore
unpatentable under Section 2 of the Patent Act. In that action the Examiner
stated (in part):
...
The examiner categorizes the method of claim 1 to
incorporate the following steps.
(1) generate a process control signal
(ii) apply this signal to a process
(iii)generate a process prediction signal
(iv) apply a delay factor
(v) generate a process measurement signal
(vi) generate a correction signal
(vii)apply a controller variable input signal in a
response to above
...
Mathematical methods are disclosed to equate each of the
alleged novel aspects of claim 1 as outlined below:
(1) The process (item 21) embodies a transfer function as
yell as a dead time function (page 8, line 28)
...
(2) The predictive term embodies transfer function (page 9,
line 2)
...
It is conclusive to the examiner that the steps recited in
claim 1 all relate to the computer program function and the
only embodiment disclosed is the computer program generated
one and the sub-routines to simulate the process control
system. It is concluded that the only difference from the
old structure (Smith Predicator) is the software applied.
...
An analysis of claim 11 reveals that a process controller is
used to generate a process control signal and consequently
argued by the applicant that this is novel apparatus in this
application.
It is well known that a programmable controller is well
suited to a variety of applications and offers logic in an
easily programmable system which will operate in an
industrial environment. Furthermore, a controller resembles
a memory. However, the fact remains that it is a programmed
machine and differs from a computer only in its level of
sophistication. This situation could be compared to
generating a logical or function using either diodes or a
linear element where both provide the same functional
result.
In consideration of the fact that no unique apparatus or
novel combination is disclosed it is held that no novelty
exists.
...
Since the disclosed programming is not carried out with
specific new fully disclosed apparatus devised to implement
a new method of process control, the disclosure and claims
are rejected as being essentially directed to an algorithm
for controlling a process and therefore unpatentable subject
matter under Section 2.
...
The Applicant did not agree with the Examiner and argued (in part):
...
The claims are directed to method and apparatus for
controlling a process and not simply to an algorithm or
computer program. Certainly mathematics is involved in the
process control but it is difficult to imagine any type of
process control which does not rely on some type of
mathematics even if it is a simple comparison. However,
even though mathematics are involved in the process control
it is respectfully submitted that the claims are not
directed to an algorithm or a computer program but are
rather directed to method and apparatus for controlling a
process. The claimed process control requires measurements,
control of a process in response to certain signals and the
calculation or generation of certain signals. It is
recognized that parts of the process control claimed could
be implemented on a digital computer but that does not lead
to the conclusion that the claims are directed to an
algorithm or a computer program.
Referring specifically to the independent claims, claim 1
requires the generation of a process control signal. This
process control signal could be generated using a digital
computer or could be generated using a large variety of
process controllers which are manufactured by numerous
vendors. Claim 1 also requires that the process must be
controlled in response to the process control signal. This
is not a computer program but is rather process control
based on a control signal.
Claim 1 further requires the generation of a process
prediction signal and the applying of a delay factor to that
process prediction signal to produce a delayed prediction
signal. It is recognized that these two steps could be
implemented on a digital computer but the fact that certain
method steps in a claim can be carried out in a digital
computer does not necessarily lead to the conclusion that
the claims are directed to a computer program. These method
steps define specific steps which must be taken in
controlling the process.
Claim 1 further requires the generation of a process
measurement signal. Typically a process measurement signal
is provided by a measurement device such as a chromatograph.
The final two steps in claim 1 are based on mathematics and
could be carried out by means of a digital computer but it
is again respectfully submitted that these method steps are
specific steps required to control the process and are not
simply a computer program.
In summary with respect to claim 1, it is pointed out that
two specific steps are totally outside any type of computer
program and other steps while mathematical in nature could
be implemented by means other than a computer program. It
is recognized that mathematics is involved in some of the
method steps of claim 1 but it is respectfully submitted
that claim 1, when taken as a whole, is directed to specific
method steps required to control a process. The novelty
lies in the predictive manner in which a process is
controlled and does not lie in any specific computer
program.
Referring now to the independent apparatus claim 11, there
is required a process controller means for generating a
process control signal. A process controller means can be
implemented on a digital computer but can also be
implemented by using a number of different types of process
controllers which are manufactured by a number of different
venders. Claim 11 further provides means for providing a
process measurement signal. This would typically be a
measurement instrument such as a chromatograph,
thermocouple, etc. Claim 11 further requires a process
model means, means for generating a correction signal in
response to a ratio and means for multiplying. It is
recognized that mathematics is involved in the operation of
this apparatus. However, this does not necessarily imply
that a digital computer programmed in a specific manner is
being claimed. This apparatus could also be implemented
outside a digital computer. Further, this apparatus is
specific apparatus required for the process control of the
present invention.
...
...When claim 11 is taken as a whole, it can be seen that
the claim requires not only a process controller but also
requires specific measurement apparatus and other control
apparatus which when combined in the manner required
provides novel apparatus for controlling a process. Thus,
the claim does not rely on the presence of a process
controller for novelty. Further, the claim is not directed
to a digital computer programmed in a specific manner but is
rather directed to a specific apparatus which is required
for controlling a process in accordance with the present
invention. Some of the apparatus required is measurement
apparatus and other apparatus could be easily implemented
onside by a digital computer.
...
...it is noted that the novelty in the present invention, as
claimed, does not lie solely in a program or algorithm but
lies in specific steps or apparatus required to control a
process in accordance with applicant's invention. Some of
the steps require measurements. Others require control of a
process in response to certain signals. Others are
mathematical in nature but are still specific steps required
to control the process in accordance with applicant's
invention. When taken as a whole the claims do not define a
computer program and certainly the novelty does not lie
solely in a computer program or algorithm.
...
The issue before the Board is whether or not the application and all claims are
directed to patentable subject matter under Section 2 of the Patent Act. Claim
1 reads:
A method of controlling a process, said method comprising:
generating a process control signal in response to a
comparison of a controller variable input signal and a
controller setpoint signal;
applying said process control signal to said process to
effect control thereof;
generating, in response to said process control signal, a
process prediction signal representative of the predicted
response of a measured process variable to said process
control signal;
applying a delay factor, modeled after the response delay of
said process, to said process prediction signal to produce a
delayed prediction signal;
generating, a process measurement signal representative of
the value of said measured process variable;
generating, in response to said process measurement signal
and said delayed prediction signal, a correction signal
responsive to the ratio of said measured process variable to
the delayed process response prediction; and
generating said controller variable input signal in response
to the product of said process signal and said correction
signal.
It may well be that the method and means of the application have used
calculations to arrive at altered signals, but the end result of the signals
is an altered process and not merely a display of information. We find
therefore that something more than a mere algorithm has been advanced by
Applicant, and that the application is directed to patentable subject matter.
In the prosecution of Applicant's corresponding United States application,
United States patent 3,558,045 January 26, 1971 to Smith et al was cited.
We note that Applicant's system is different from the system of the Smith
predictor circuit noted by Applicant. In the Smith predictor, the subtracting
means acts on a signal coming from a process in order to produce a correcting
signal which is used in controlling a process, and in the patent a correcting
signal is used in controlling chemical reactions. Applicant uses a correcting
signal in process control systems including electrical analog, digital
electronic, pneumatic, mechanical, hydraulic, and other control system formats.
We are impressed by the fact that Applicant has used different means from those
in the Smith patent. We note however that the Smith patent was not cited by the
Examiner.
We find that the claims are also directed to patentable subject matter. In so
finding however, we observe that all of the claims do not adequately define the
method and means of dividing the process signal and the delayed prediction
signal to produce an interim signal, and of providing a multiplying effect to
the interim signal and a process prediction signal so that a correction signal
is obtained which is representative of on-going changes in a process.
In summary, we are satisfied that the application discloses patentable subject
matter and that in the absence of cited art it may be properly claimed.
We recommend that the rejection of the application and claims as being directed
essentially to an algorithm be withdrawn and that the application be returned to
the Examiner for further prosecution leading to acceptable claims.
A. McDonough M.G. Brown S.D. Kot
Chairman Assistant Chairman Member
Patent Appeal Board
I concur with the findings and recommendation of the Patent Appeal Board.
Accordingly, I withdraw the Final Action, and I am remanding the application to
the Examiner for further prosecution consistent with the recommendation.
J.H.A. Gari‚py
Commissioner of Patents Agent for Applicant
Herridge, Tolmie,
Dated a Hull, Quebec 116 Albert St.
this 5th. day of August, 1983 Ottawa, Ont.