Method of regulation and regulating device for an apparatus or group of apparatuses, as well as an apparatus having a regulating device

The method of regulation employs a simulation process for at least one state variable of an apparatus to be controlled and regulates the state variable. In the process, a curve of an operating characteristic having its base at an idle state value is traversed up to an operating state value. When re-regulating, the regulation process begins at the current value of the state variable. The value of the regulation variable corresponds to the idle state. This has the advantage of a defined initial point for re-regulation. A regulating device for performing the method of regulation comprises a series circuit containing an input circuit, a regulation circuit with a simulation device for regulating an apparatus as well as a control circuit for possible machines coupled to the apparatus. The simulating device is adjustable according to operating characteristics or apparatus parameters. Another regulating device fulfills the same function while employing a computer and correspondingly modified circuits.

BACKGROUND OF THE INVENTION 
The present invention broadly relates to the regulation of apparatus and, 
more specifically, pertains to a new and improved method and device for 
regulating an apparatus or group of apparatuses and to an apparatus having 
a regulating device. 
The apparatus to be regulated can, in particular be arranged to process 
fabric edges or selvedges and can, for instance, be an electrothermal 
shear. 
Fabric edges or selvedges are in many cases and independently of the 
weaving process severed or cut off in weaving. The newly formed fabric 
edge must be bonded. 
In woven fabrics which comprise synthetic fiber components, the fabric 
edges or selvedges are often severed by means of a thermal or heated shear 
which welds or fuses the newly formed fabric edges during the severing 
process. In fabrics without a substantial synthetic fiber content, special 
measures must be taken and special devices employed in order to bond the 
fabric edges. 
However, an exact control of the operation of this processing device in 
relation to the materials employed in the woven fabric is required for 
both groups. 
In heretofore known devices, especially in known thermal shears, this is 
not the case. 
For example, one known thermal shear comprises a heated rod containing a 
potentiometer coupled to the rod which is pivotable in a joint or hinge 
and is journaled to swing or pivot in a direction extending substantially 
transverse to the plane of the fabric length. This known thermal shear is 
pressed against the initial or forward edge of a fabric length by means of 
a spring. In the nearly vertical idle position, the potentiometer feeds a 
current into the rod which prevents the rod from heating too strongly or 
from heating at all. As the rod is deflected by the traveling fabric 
length, the potentiometer feeds a current into the heated rod enabling the 
rod to sever the fabrics. 
This thermal shear has the disadvantage that the heated rod continues to 
melt the fabric with its residual heat after the cloth of fabric length 
has ceased to move and the cutting or severing current has been switched 
off. Since the fabric length no longer moves, damage to the fabric occurs 
in the region of the idle position of the only slowly cooling rod. 
Another electrothermal cutting apparatus is known from the German Pat. No. 
3,140,560 and comprises a circuit arrangement for regulating the supply of 
current during the operating interval and during the idle interval. The 
circuit arrangement automatically sets a higher current supply at the 
beginning of the operating interval and switches it off again at the end 
of the operating interval. The circuit arrangement also comprises 
circuitry operating according to the phase shift control method and having 
adjustable delay circuits and a switching device actuated by the drive of 
the machine being regulated. The time constant of the first delay device 
depends upon the position of a closure contact controlled by the 
processing machine. Both delay circuits conjointly with a power control 
stage effect a phase shift control whose firing or triggering angle is 
determined by the two delay circuits. 
The magnitude of the firing or triggering angle determines the onset and 
the duration of the current flow through the power control stage and 
through the cutting or severing device. The current flow or flux can be 
adapted to the type and thickness of the fabric to be severed as well as 
to the operating and idle intervals. A substantial disadvantage of this 
circuit arrangement is the very slow temperature rise at the shear or 
shears when switching from the idle interval to the operating interval. 
For rapidly operating machines this temperature rise occurs too slowly, 
which leads to fabric waste or scrap. 
SUMMARY OF THE INVENTION 
Therefore, with the foregoing in mind it is a primary object of the present 
invention to provide a new and improved method and device for regulating 
an apparatus as well as an apparatus regulated by the device and method 
which do not have associated with them the aforementioned drawbacks and 
shortcomings of the prior art constructions. 
Another and more specific object of the present invention aims at providing 
a new and improved method and device for regulating an apparatus or group 
of apparatuses enabling the alternation between two values of at least one 
state or operating variable to be very rapidly effected. For instance, 
when switching from the idle or rest state to the operating state, the 
value alternation is to be effected very rapidly. In particular, such a 
regulation device is to be connected to an apparatus for cutting off or 
severing the fabric edges or selvedges from a fabric length. 
Yet a further significant object of the present invention aims at providing 
a new and improved construction of a device of the character described 
which is relatively simple in construction and design, extremely 
economical to manufacture, highly reliable in operation, not readily 
subject to breakdown or malfunction and requires a minimum of maintenance 
and servicing. 
Now in order to implement these and still further objects of the invention, 
which will become more readily apparent as the description proceeds, the 
method of the present invention is manifested by the features that it 
comprises the steps of tapping or extracting at least one state or 
operating variable of the apparatus to be regulated from the apparatus to 
be regulated or from a control circuit of the apparatus to be regulated, 
conducting the tapped state or operating variable to a simulation circuit 
for simulating a variable of an operating characteristic of the apparatus 
to be regulated, and conducting the simulated value of the operating 
characteristic to a comparison and regulation circuit for regulating the 
apparatus. 
The device of the present invention is manifested by the features that it 
contains an input circuit, a regulation circuit connected to the input 
circuit and a control circuit connected to the regulation circuit. 
The apparatus of the present invention is manifested by the features that 
it comprises an apparatus for severing or cutting off selvedges of fabric 
lengths.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Describing now the drawings, it is to be understood that to simplify the 
showing of the drawings only enough of the structure of the device has 
been illustrated therein as is needed to enable one skilled in the art to 
readily understand the underlying principles and concepts of this 
invention. The illustrated exemplary embodiment of the device will be seen 
to comprise an input circuit 210, a regulation circuit 220 and a control 
circuit 230. In the method of regulation according to the invention 
momentary value of at least one state of operating variable are tapped off 
or extracted from the apparatus to be regulated, for instance the voltage 
or the current or the power, and conducted to the regulation circuit 220. 
These momentary values of the state or operating variable are converted in 
the regulation circuit 220 and a preselected course of variation of every 
operating characteristic of the apparatus is simulated in a simulating 
device 223 by means of the state or operating variables. Feedback signals 
for the regulation of the apparatus are generated from this course of 
variation as well as from apparatus parameters. 
In producing each feedback signal, the tapped and converted signal 
corresponding to the state or operating variable is combined with signals 
corresponding to specific device properties, the so-called apparatus 
parameters. It is combined, for instance, with signals corresponding to 
the particular type of apparatus 100 or with machine constants. The 
simulating device 223 simulates the behavior of the apparatus, i.e. the 
course or variation of the value of at least one of the operating 
characteristics of the apparatus in dependence of the state variables and 
of the apparatus parameters. For instance, in an electrothermal severing 
or shearing device one of these operating characteristics can be the 
temperature at the cutting wire. The particularly rapid rise of this 
cutting wire temperature when the apparatus is initially set in operation 
occurs between the idle temperature and the operating temperature. 
The simulation can, for example, be performed with precisely the power 
applied to the apparatus as a state or operating variable or with a value 
exactly proportional thereto as a state or operating variable. Instead of 
the power, however, another parameter characteristic of the operation of 
the apparatus could also be employed as a state variable. 
The regulation of the course or variation of the value of the operating 
characteristics can either be performed while taking into account the 
values of the system parameters; the alternation of the values then 
proceeds according to an operating characteristic which is adjusted 
according to these values of the system parameters; it is not dependent 
upon a possibly prescribed or prescribeable operating characteristic; or 
the course or variation of the value of the operating characteristic can 
occur in dependence of a prescribed reference operating characteristic 
i.e., a reference course of variation of such operating characteristic, 
wherein the practically arising actual operating characteristic is 
compared with the reference operating characteristic. 
According to this comparison, respectively according to the deviation of 
the actual values from the reference operating characteristic, the values 
of the system parameters are readjusted or regulated such that the course 
or variation of the values of the operating characteristics proceeds 
according to the reference operating characteristic. In this manner it is 
possible to maintain approximately the same run-up time under any load and 
independent of the number of apparatuses. 
The selection of a considerably higher heat-up operating temperature for 
regulation than the actual operating temperature is of basic importance 
for this method of regulation with, for instance, the temperature at the 
cutting wire as one of the operating characteristics. In this manner, a 
considerably steeper or very high slope branch or region of the 
characteristic curve, for instance a logarithmic function to the base e, 
i.e. a natural log function, which leads to the operative state of the 
apparatus, can be selected and thereby a correspondingly shorter time 
interval for the heating-up process to the actual operating temperature 
obtained. 
Upon attaining the operating temperature, this temperature is maintained 
constant by the regulation device, i.e. the characteristic curve is 
essentially extended or continued at this point by a straight (horizontal) 
branch. This eliminates the asymptotic approach to the operating 
temperature which requires a great deal of time. The overshoot due to 
technical conditions generally remains in negligible orders of magnitude. 
Furthermore, for every re-regulation process, whether for maintaining the 
operating temperature constant or after an interruption of operation and 
partial cooling off of the electrothermal cutting device, regulation in 
this method of regulation begins at the final temperature corresponding to 
this cooling-off, but the heating-up current imposed upon the apparatus 
has a value corresponding to the state in which the characteristic curve 
runs through the base point, i.e. the idle temperature point, as will be 
understood from FIGS. 1a and 1b. 
This method of regulation can be more precisely and more rapidly executed 
than other methods. This is especially true because the same unambiguously 
defined run-up curve is always employed. 
The feedback signal is supplied to a comparison and regulation circuit 
which controls the apparatus and other circuits, for instance a control 
circuit. 
The apparatus to be regulated can, as mentioned, be an electrothermal 
severing or cutting apparatus 100 for woven material. Such severing 
apparatuses or selvedge cutters are preferably mounted on the weaving 
machine at the edges of a fabric length. They sever the fabric edges or 
selvedges from the traveling fabric length. The thus newly created fabric 
edges are simultaneously bonded by the severing process, in particular 
they are welded or fused when the fabric contains synthetic fibers. 
One or more electrothermal severing apparatuses 100 can be connected to a 
regulating device 200 for controlling and regulating the power supply and 
the stages of operation. 
A roller shear with a bonding device, or similar apparatus, can be provided 
for producing a durable fabric edge instead of electrothermal severance or 
cutting-off. 
The regulating device 200 operates according to the initially described 
method of regulation according to the invention and comprises the series 
circuit including the input circuit 210, the regulation circuit 220 and 
the control circuit 230. 
The input circuit 210 comprises an adjustable potentiometer 211 for the 
idle state temperature and an adjustable potentiometer 212 for the 
operating state temperature, both of which are connected to a switch or 
switching means 213 for switching from one operating state to the other. A 
test push button 214 is also connected to the switch 213 to throw or 
commute it between the idle and the operating state positions when pressed 
and is also operated for checking or monitoring a suitable display lamp 
218. A rectifier 216 is connected to an operating signal entry circuit 215 
for an operating signal of a weaving machine or the like (since the 
processing device, i.e. the selvedge cutter or shear, is only to be 
operated when the machine is in operation). An isolating circuit 217 for 
the galvanic isolation of the regulating device 200 from mains or line 
voltage, e.g. by means of an opto-coupler, is connected to the rectifier 
216 and also to the switch 213. 
The output 213A of this switch 213 forms or defines the output of the input 
circuit 210 and is connected to a comparator circuit 221 on an input side 
220A of the regulation circuit 220. The comparison circuit 221 is also 
connected to an output of a simulation device 223 of the regulation 
circuit 220 and carries out a comparison between the reference values and 
the actual values supplied by these two input signals. A PI regulator 222 
connected to the comparator circuit 221 trims or adjusts the result of the 
comparison between the reference value and the actual value to zero in the 
regulating circuit branch. A phase-shift control circuit 224 is connected 
in series with this PI regulator or controller 222 and controls the 
phase-shift angle in dependence of the regulator output voltage. A 
transformer 225 whose secondary side is connected to the apparatus 100, 
for instance at least one electrothermal shear, is also connected to the 
phase-shift control circuit 224. 
Instead of a PI regulator or controller, a P, PD or PID controller or 
regulator cam also be employed. It is also possible to arrange a state 
regulator or controller as a P circuit, that is a proportional circuit, in 
a feedback connection, that is in the connection an operating 
characteristic regulating circuit 223.2 and the comparator circuit 221. A 
state controller or regulator hierarchy can also be provided when 
regulating several state variables. 
A current converter 226 for tapping off or detecting the regulated output 
variable, i.e. the current, is provided between the transformer 225 and 
the selvedge cutter or shear. This current is represented or simulated as 
a voltage value or potential drop across a resistance and is converted 
into direct current in a rectifier 227. The direct current is then squared 
in a square-law transfer circuit 228 in order to obtain an input variable 
corresponding to the power for the simulation circuit or device 223. 
If the apparatus to be regulated represents a constant load to the 
regulation circuit, then the current is regulated as the output variable. 
It is, however, also possible, according to the individual case, to 
regulate the voltage. This is especially true when several apparatuses to 
be regulated are connected in parallel to one another. 
The simulating circuit or device 223 comprises an input circuit 223.1 of 
input means 223.1, 223.2 for inputting a predetermined system parameters 
dependent upon the type of apparatus 100 to be regulated. This input can 
either be manual or automatic and governed by the construction of the 
apparatus. Furthermore, a circuit 223.2 of the input means 223.1, 223.2 
for altering the amplification factor in conformity with the type of shear 
is provided in the simulation circuit or device 223 and is controlled by 
the input circuit 223.1. An operating characteristic circuit 223.3 is 
connected with the input circuit 223.1 and with the alteration circuit 
223.2. 
The operating characteristic circuit 223.3 determines the preselected 
operating characteristic curve branch for the temperature rise from the 
idle state temperature to the operating state temperature in dependence of 
the type of processing device or shear and in dependence of its regulation 
parameter correspondingly transformed or converted by the circuit 223.2 as 
well. The operating characteristic circuit 223.3 correspondingly transmits 
a continuous feedback signal as its output to the comparator circuit 221. 
In the present case, the temperature behavior is simulated in dependence 
of the time of the processing apparatus in this simulation circuit 223 and 
there is generated a corresponding feedback signal. 
In one embodiment, besides taking into account the type of processing 
apparatus, parameters which are determined by the mounting on the 
processing machine, for instance the weaving machine, can be input into 
the simulation device 223. This can, for instance, be accomplished by a 
modified circuit 223.2. 
The circuit 223.2 for altering the amplification factor or gain can also be 
connected at another point of the regulation device 200, for instance 
ahead of the switch 213. 
The regulation circuit 220 is designed or dimensioned such that the same 
operating characteristic curve branch is always traversed in every 
heating-up regulation process. After an interruption of operation and a 
partial cooling off of the electrothermal cutting or shearing device, the 
regulation begins again at the final temperature corresponding to this 
degree of cooling off at the higher value of heating up current 
corresponding to the initial or base point of the operating characteristic 
curve, i.e. the idle state temperature, as can best be understood with 
reference to FIG. 1b. 
The control circuit 230 is connected both to the output of the PI regulator 
or controller 222 and to the output of the rectifier 227. The PI 
controller or regulator 222 is connected to one input 232.3 of an AND gate 
232 whose other input 232.1 is connected to an inverter 231. The inverter 
231 is connected to the rectifier 227. The AND gate 232 controls via its 
output 232.3 an output relay 233 for controlling a machine, for instance a 
weaving machine. 
The control circuit 230 transmits a termination-ofoperation signal to the 
processing machine only when the apparatus 100 has been damaged. During 
current-free intervals generated by the regulation circuit, no 
termination-ofoperation-signal is generated. 
In another embodiment of the regulation device according to the invention, 
an input circuit 310 for inputting the values for the idle state 
temperature, the operating state temperature, the type of apparatus to be 
regulated and the functions for calibrating and testing or for displaying 
these values or for both inputting and displaying these values is 
connected to a computer or control processor 320. The computer 320 is also 
connected to an entry circuit 350 for receiving or inputting an operating 
signal, for instance from a weaving machine at the start of the weaving 
operation. A control circuit 330 which supplies the apparatus to be 
regulated with power and which derives signals of one or more of the 
apparatus' state variables and processes them is also connected to the 
computer 320. 
In addition to the means for tapping or detecting and processing the 
signals for at least one of the state variables, for instance the current 
converter 332 and the rectifier 333 and so forth the control circuit 330 
also comprises an electronic power switch 331. The power switch 331 and 
the rectifier 333 are connected to the computer 320. Signals flow from the 
computer to the electronic power switch 331, respectively from the 
rectifier 333 to the computer 320. The current converter 332 is arranged 
ahead of the apparatus 100 to be regulated in the conductor or lead coming 
from the electronic power switch 331. The latter adjusts the width of the 
pulses for supplying energy to the apparatus on the basis of signals 
coming from the computer 320 in the manner of a pulse-width controller. 
Furthermore, an output circuit 340 is connected to the computer 320 and 
comprises means for transmitting control signals to a machine linked to or 
connected in series with the apparatus, for instance a weaving machine, as 
best will be seen in FIG. 3. 
The apparatus 100 to be regulated can, in particular, be a heated wire 
shear device or a roller shear device having means for thermally bonding 
fabric edges. 
While there are shown and described present preferred embodiments of the 
invention, it is to be distinctly understood that the invention is not 
limited thereto, but may be otherwise variously embodied and practiced 
within the scope of the following claim. Accordingly,