ELAPSED

Nov. 15, 1960
w. E. CHOPE ETAL.
-
2,960,268
RATIO COMPUTER
Filed March 2a, 1958
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MULTIP‘LY
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53
INVENTORS
WILBERT E. CHOPE
WALKER B. LOWMAN
PERGEL
lgy
: ‘ ‘MI-LIP
M
2,950,268
Patented Nov. 15, 1960
2
typical embodiment of a production ratio computer of
the present invention.
Fig. 2 is a graphical representation of production goal
2,960,268 '
versus production.
A mathematical representation of the number of
RATIO COMPUTER .
‘Wilbert
pieces that should have been produced up to any moment,
with a goal that has been changed and uniform produc
tion rates before and after goal change is:
Chope, Walker. B. Lowman, and Philip
Spergel, il‘olumbus, Ohio, assignors to Industrial Nu
cleonics Corporation, a corporation of Ohio
Filed Mar. 26, 1958,Ser. No. 724,164
11 Claims. (Cl. 235-193)
10
where :
t=elapsed time
'
This invention relates to a production ratio computer 15 yx=t=otal production goal
yk=production at time tk when goal is changed during
and more speci?cally to method and means for determin
production time
'
ing the ratio of quantities or qualities of the pieces pro
tk=time when goal is changed
duced from a continuous production line‘ to the goal
t2=total production time, i.e., duration of production
set for the number of pieces desired to be produced by
period
.
the process or measures of their qualities.
20
y=goa1
at
any
time
t
In all manufacturing processes, there are a number of
variables that describe conditions of the process, such as,
This equation de?nes the value of a goal at any time
the speed of the process, the number of pieces produced,
I when the total goal yX for a production period is set.
and the weight of the pieces. These variables are gen
If the goal is not changed during the production period,
erally found in two areas, quality and quantity. In 25 then yk and tk are equal to zero. If the goal is changed
either area, the manufacturer can set a goal ?gure, while
vafter production has started, yk is equal to y at the
measurements of the process and product de?ne actual
time the goal is changed, and tk is equal to the elapsed
qualities and quantities which may or may not coincide
production time t at the time the goal is changed.
with the goal. It is quite important for the operator
The ratio of ‘the actual production quality or quantity
of a manufacturing process to know at all times how 30 by continuous measurement to the goal as determined in
closely the qualities ‘and quantities of his process and
the equation above is
product attain to the goals. A single statistic which ‘
_ actual 'produ ction
contains this information is the ratio of the actual qual
:2
— goal production
ity or quantity to the goal.
y
In the past it has been customary to establish goals 35
Referring now to the block schematic diagram of Fig.
for qualities and quantities relating 'to the production
1 there is shown an operable embodiment of functional
and then to measure by whatever means was, available ‘
elements for computing the ratio of actual production
the‘ actual quality or quantity. From these ?gures the
versus the goal production as expressed above.
operator would draw hisconclusions as to'the relation
, At the beginning of the production period the value
ship of the two values. To complicate matters further 40 for total production goal yx is set on a graduated selector
many manufacturing processes today are continuous, that
‘10 and the value for the total production time t2 is set on
is, the product produced is formed in one manner or an
graduated selector 20. Each of the selectors 10 and 20
other from a continuous sheet, rod, web, etc., of ma
can be a manually operated potentiometer to provide
terial. The actual values of the variables are deter
a voltage, either A.C. or DC, proportional to the set
mined in most instances by the sampling-method and 45 ting. The selectors 10 and. 270 can also bev multi-wafer
then compared with'the goal desired. ' p I, ; .
p
switches -(such as digital converters) so that the shaft
The present invention provides a system for automati
position can be directly converted to a coded digital form.
cally and continuously computing for ratio between the
This converted signal can then be inserted into digital
quantity and quality of a product and the desired goal.
computer elements.
It is accordingly an object of the present invention to 50 The voltages ‘from the selectors 10 and 20‘ are fed to
provide a single accurate statistic which can serve as the
the add circuits 12 and 22 respectively. These add units
basis for vital operating decisions. will provide for the addition of two variables. The
It is another object of the present invention to auto
computation can be performed by the use of an elec-_'
matically compute the ratio between actual measure
tronic operational summing ampli?er, or a serial or
ment of a variable of a product from. a manufacturing 55 parallel digital arithmetic unit that is commercially
process and the goal set by the operator of the process.
available. If an operational ampli?er is used, A.C. or
It is a further object to compute the ratio between
DC. signals representing the variable can be used. How
the actual measurement of a variable and a goal of a
ever, if the digital unit is used, signals from the selectors
product produced by a continuous process.
10 and 20 should be ?rst converted to a coded form.
Another object is to compute the ratio between the 60 This may be accomplished by a shaft position encoder
actual measurement of ‘a variable and av goal that has
that is commercially available. The add device 12 is
been changed from time to time for a continuous process.
operative to add the following sums of variables:
Still another object is to provide apparatus for com
puting the ratio between the actual measurement of a
variable and ya goal that is simple. and inexpensive in 65 add device 22 adds t2+(—)tk; and add device 18 add
construction and readily adaptable to present day manu
facturing processes.
'
'
t+(_)tk-
‘
The outputs of the add circuits 12 and 22 are fed to
Other objects and features of the present invention
will become apparent from the following detailed de
the divide circuit 14 to provide the divisional operation.
Fig. l is a block diagram schematically illustrating a
will be a voltage proportional to the division of the two
variables. The division computation can also be per
The divide circuit 14 or the divide circuit 30 can be an
scription when taken in conjunctionwith the drawings 70 electronic or a servo-system divider and whose output
in which:
a
>
2,960,268
3
()lxfyk), by. (ta-i10-
4
switches 15 and 17 through relay system 53 from the
values of yk and 1;, to those which pertain at the time the
formed by a digital arithmetic unit if it is desired that
the inputs should then be in the form of coded digits.
More speci?cally the divide unit 14 is operable to divide
new goal is selected. The memory circuits 24 and 32
are also reset to zero momentarily before the entry of
yk and tk to insure that they contain no residual informa
tion. It is appreciated that if a digital system is used
,
The outputs of the divide circuit 14 and the add circuit
18 are fed to the-multiply circuit 16 to provide for the
the operation of clearing the memory circuits and reset
multiplication operation of the ratio formula. This unit
ting the selectors cannot be simultaneous and must be
done sequentially. This can be performed by a one shot
can be an electronic or a servo-system multiplier, similar
tothe divide circuit 14, and can also be performed by
a_,digital arithmetic unit if it is desired that the inputs be 10 multivi'orator in combination with a relay closure system.
When the goal is reset the operational steps of the vari
in the form ofcoded digits. ‘The multiply unit 16 is oper
ous circuits to compute the mathematics of the ratio of
able to feed to the add unit 28, the result of
actual versus goal vis continuously performed without
iii-ii by <i— it)
interruption.
Fig. 2 is a graph of the mathematical equation for rep
resenting the goal or the number of pieces that should
have been produced up to any moment. yk is the actual
from memory circuit 32 when there has been a goal
or anticipated production at time tk. I2 is the total pro
change. The add circuit '28, operable in a manner simi
duction time and yx or yxg are the required production
lar to add circuits 18 and 22, then performs the operation
20 goals. The value yx is a change in the value of goal from
15
Also fed to add circuit 28 is the voltage representing yk
yxz at the time tk.
The memory unit can be a servo repeat potentiometer
which is clamped in its last position. At the time that
It is seen from the above, the add circuits 12, 18 and
the reset switch 44 is thrown the reset signal will remove
22, the divide unit 14, and the multiply unit 16 solve the
the clamp on the servo and permit a new signal to be
25
equation given above for y.
memorized on the servo driven potentiometer. The out
~When production begins, production counter 38 meas
put can be a voltage proportional to the memorized vari
tires the production variable, such as the number of pieces
able and may be converted to a digital code by the use
being produced by the manufacturing process. The coun
of a digital converter. The memory operation can also
ter 38 can be either electronic or electromechanical with
an input'that is preferably an electrical signal represent 30 be performed by the use of a magnetic drum, tape or
ing each completed piece of production. Such a counter
is described in co-pending application, Serial No. 707,035
Production Counter, ?led January 3, 1958, by Walker B.
core memory device.
Digital information relating to
number of pieces produced.
the production periodto some maximum value at the end
the variable would be put into the memory unit so it
could be available for computation as it is needed.
The example described‘ above relates to a production
Lowman. The output of the counter 38 can be switch
variable
which increases from zero at the beginning of
35
closures, pulses, or other means of representing the total
of the production period. In the illustration, the goal
The counts from the counter 38 are accumulated in the
accumulator 36. The accumulator unit 36 can also be
electronic or electromechanical and may be an electronic
also accumulates from zero to some ?nal value which has
been set into the invention by means of a suitable con
operational feedback integrating ampli?er for an analog 40 trol. If the actual measured value and the goal are
varying, but not accumulating values, the invention 'sim
computation system. The output signal from the accu
pli?es to a computation of the ratio of a measured value
mulator 36 will then be proportional to the integral of
to its ‘goal at any instant without concern for time.
the number of input production counts from counter 38.
It should be understood that the above-described are
An electro-mechanical accumulator such as a ball and
disk integrator, may also be used. A digital accumulator 45 rangements are merely illustrative of the principles of
this invention, and that structural modi?cations can be
can take the form of a shift register wherein the count
made without departing from the scope of the invention.
information is taken from the production counter and
What is claimed isi
shifted into the register at the time of computation. The
1. A production ratio computer as herein described
register can then shift the information to a digital com
puter or' to a digital to analog converter for processing 50
in analog form. The accumulator unit 36 output contains
for determining
g
the information 17 that represents the actual production.
y
The output from 36 is fed to divide circuit 30 where it is
divided by the production goal y to give the ratio p/y.
In many instances a particular goal isset for a par
wherein r is the ratio, p is the production variable and y
55 is the goal comprising: means for computing the value
ticular time, but for one reason or another may turn out
of the goal at any time when the total goal for a produc
to be unrealistic. Rather than have the system continue
tion period has been set as expressed
to compute the actual production ?gure with an unrealis
tic goal there is provided in the present invention method
and means for changing the goal at any time during the 60
production period without disrupting or affecting the
operation of the system.
where :
When it has been ‘determined that the goal for the par
t=elapsed time
ticular process should be changed there is provided means
to utilize the information already accumulated together 65 yx=total production goal
yk=production at time tk when goal is changed during
with means for resclecting the goal without interrupting
production time
the system. To change the goal, the selector 48 enables
tk=time when goal is changed
the operator to determine at that time if the initial con
t2=total production time, i.e., duration of production
dition for the new computational period is to be yk equal
period
to y, or equal to p. After this has been determined, the
operator selects a new value of yx and t2 on selectors 11
y=goal~ at any time:
and 13 respectively. These selectors are identical to
selectors 1t} and -20. The closing of the operator’s reset
including, ‘a pair of selector means for selecting the volt
age values)’; and t;,, a, pair of storage means for providing
switch 44 provides a voltage from source 51 to the
memory circuits 24 and 32 and simultaneously throws 75 the voltage values y'k and tk and circuit means having fed
2,960,268
5
thereto said voltage values from said selector and storage
means operative to solve
ing the results of said ?rst and second circuits thereto to
divide (y,,——yk) by (t2—tk), a multiply means and means
feeding the output of said divide means thereto, a third
circuit, a timing means for providing a voltage value for
t, means for applying said time voltage 1' and said volt
age tk from said second memory means to said third
circuit, said third circuit operable to add t-I-(—~)tk, means
to apply the output of said third circuit to said multiply
means to multiply the result of said divide means by
'
to provide the voltage 3/, said pair of storage means
connected to the said circuit means to provide the
voltage yk for the production when the goal is changed
and voltage tk for the time when the goal is changed;
means for determining the production variable p, and 10 (t—tk), a fourth circuit and means for feeding the out
means having fed thereto said values p and y for per
put of said mutiply means and said second memory means
‘forming the operation p/y.
thereto, said fourth circuit operable to solve
2. A computer substantially as set forth in claim 1
wherein said means for determining the production count
p comprises a counter and an accumulator for accumulat
15
ing the counts.
3. A computer substantially as set forth in claim 1
and further including reset means for resetting said ?rst
to provide the voltage y, said ?rst memory means con
nected to said fourth add circuit and operable to con
and second storage means when the goal is changed dur- '
ing production.
tinuously store the information received therefrom to
provide said voltage yk equal to the production when the
20 goal is changed during production time, said second mem
4. A computer substantially as set forth in claim 1
and further including second means for selecting said
value yx, second means for selecting the value t2, and
switching means to switch from said ?rst to said second
means when said goal is changed.
5. A computer substantially as set forth in claim 1
wherein said voltages tk and yk are equal to zero thereby
indicative that the production goal has not been changed
ory means connected to said timing means and operable
to continuously store the information received therefrom
to provide said voltage 1,, equal to time when goal is
changed; means for determining the count of said produc
tion varable p, a second divide means, and means feeding
thereto said voltage p and y to perform the operation
of p/y.
10. A computer substantially as set forth in claim 9
wherein said voltages tk and )1]; are equal to zero thereby
during said production period.
6. A computer substantially as set forth in claim 5 30 indicative that the production goal has not been changed
wherein said means for determining the production count
during said production period.
p comprises a counter and an accumulator for accumulat
11. A production ratio computer as herein described
ing the counts.
for determining
7. A computer substantially as set forth in claim 5
and further including reset means for resetting said ?rst 35
T=B
11/
and second memory means when the goal is changed
during production.
wherein r is the ratio, p is the production variable and y
8. A computer substantially as set forth in claim 5
is the goal comprising means for computing the valve of
and further including second means for selecting said
the goal at any time when the total goal for a production
40
value yx, second means for selecting the value t2, and
period has been set as expressed
switching means to switch from said ?rst to said second
means when said goal is changed.
9. A production ratio computer as herein described for
determining
where :
45
t=elapsed time
X=total production goal
yk=production at time tk when goal is changed during
wherein r is the ratio, p is the production variable and y
production time
is the goal comprising: means for computing the value of
the goal at any time when the total goal for a production 50 tk=time when goal is changed
period has been set as expressed
t2=total production time, i.e., duration of production
period
y=goal at any time 1‘
where :
t=elapsed time
yx=total production goal
yk=production at time 1,, when goal is changed during
production time
Ik=time when goal is changed
including, selector means for selecting the voltage value
55 for yx, a ?rst add circuit and means for feeding said volt
age to said add circuit, selector means for selecting a volt—
age value for t2, a second add circuit and means for feed
ing said time voltage to said second add circuit, a ?rst
memory means for providing a voltage value for yk, and
60 means for feeding said voltage yk to said ?rst add circuit,
t2=total production time, i.e., duration of production
said ?rst add circuit operable to add yk+(—)yk, a sec
period
ond memory means for providing a voltage value for tk,
=goal at any time t
and means for feeding said voltage 13, to said second add
circuit, said second add circuit operable to add t2+(—)tk,
including: means for selecting the voltage value for y,,, 65 a ?rst divide circuit and means for feeding the results of
a ?rst circuit and means for feeding said voltage to said
said ?rst and second add circuits thereto to divide (yx—yk)
circuit, means for selecting a voltage value for t2, a second
by (t2—tk), a multiply circuit and means feeding the out
circuit and means for feeding said time voltage to said
put of said divide circuit thereto, a third add circuit, a
second circuit, a ?rst memory means for providing a
timing means for providing a voltage value for t, means
voltage value for yk, and means for feeding said voltage
for applying said time voltage 1‘ and said voltage from
3*], to said ?rst circuit, said ?rst circuit operable to add
said second memory means tk to said third add circuit,
yk+(~)yk, a second memory means for providing a
said third add circuit operable to add t+(——)tk, means
voltage value for tk, and means for feeding said voltage
to apply the output of said third add circuit to said mul
tk to said second circuit, said second circuit operable to
tiply circuit to multiply the result of said divide circuit
add t2-|-(——)tk, a ?rst divide means and means for feed 75 by (2-41,), a fourth add circuit and means for ‘feeding
2,960,268
8
to provide said voltage tk equal to time when goal is
changed; means for determining the production count of
the output of said multiply circuit and said second mem
ory means thereto, said fourth add circuit operable to
solve
said variable p, a second divide circuit, and means feed
'
ing thereto said voltage value. of p and y to perform the
5 operation of p/y.
References Cited in the ?le of this patent
to thereby provide the voltage y, said ?rst memory means
connected to said fourth add circuit and operable to
continuously store the information received therefrom to
provide said voltage yk equal to the production when the
goal‘ is changed during production time, said second mem
ory means connected to said timing means and operable
to continuously store the information received therefrom
UNITED STATES PATENTS
10
2,500,545
2,582,588
2,651,456
2,787,428
Herbst ______________ __ Mar. 14,
Fennessy _____________ __ Jan. 15,
Highstone ____________ __ Sept. 8,
Schuck _______________ __ Apr. 2,
1950
1952
1953
1957

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