U.S. patent application number 11/569714 was filed with the patent office on 2007-12-06 for method for control of linear drive devices for a thread-like product in particular a textile thread during the start-up phase and device for carrying out the same.
This patent application is currently assigned to RIETER TEXTILE MACHINERY FRANCE. Invention is credited to Philippe Flechon, Cedric Milord.
Application Number | 20070277717 11/569714 |
Document ID | / |
Family ID | 34946016 |
Filed Date | 2007-12-06 |
United States Patent
Application |
20070277717 |
Kind Code |
A1 |
Flechon; Philippe ; et
al. |
December 6, 2007 |
Method For Control Of Linear Drive Devices For A Thread-Like
Product In Particular A Textile Thread During The Start-Up Phase
And Device For Carrying Out The Same
Abstract
A control method for a motor driven linear drive device is
provided in which: a device control unit receives information
representative of measured speed of said device; on receiving a
start-up command, start-up of the motor is not initiated if the
measured speed is zero; information representative of the speed of
the drive devices is monitored; and a control sequence which brings
about rotation of the motor in accordance with a pre-programmed
acceleration profile is initiated when rotation of the device
caused by an external action is detected.
Inventors: |
Flechon; Philippe; (Caluire,
FR) ; Milord; Cedric; (Valence, FR) |
Correspondence
Address: |
HESLIN ROTHENBERG FARLEY & MESITI PC
5 COLUMBIA CIRCLE
ALBANY
NY
12203
US
|
Assignee: |
RIETER TEXTILE MACHINERY
FRANCE
Allee Charles Baron Z.I. Les Aureats
Valence Cedex
FR
F-26000
|
Family ID: |
34946016 |
Appl. No.: |
11/569714 |
Filed: |
May 26, 2005 |
PCT Filed: |
May 26, 2005 |
PCT NO: |
PCT/FR05/50369 |
371 Date: |
July 13, 2007 |
Current U.S.
Class: |
112/275 |
Current CPC
Class: |
B65H 51/04 20130101;
B65H 51/28 20130101 |
Class at
Publication: |
112/275 |
International
Class: |
D05B 69/10 20060101
D05B069/10 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 1, 2004 |
FR |
0451072 |
Claims
1. A method for control of linear drive devices for a thread-like
product, in particular a textile thread, during a start-up phase,
each of said devices being slaved to an electric motor, the motor
being associated with at least one control unit capable of
receiving speed and/or speed ratio set points and start/stop
commands, wherein: the device control unit is subjected to a means
of measuring the speed of said device; on receiving a start-up
command, start-up of the motor is not initiated if measured speed
of the device is zero; information representative of the speed of
at least one of the drive devices is monitored; and a control
sequence which brings about rotation of the motor in accordance
with a pre-programmed acceleration profile is initiated when
rotation of the device caused by an external action is
detected.
2. A method as claimed in claim 1, wherein, when rotation of drive
device caused by an external action is detected, a control sequence
which brings about rotation of the motor is only initiated if a
direction of said rotation matches a pre-determined direction of
rotation.
3. A method as claimed in claim 2, wherein, if the direction of the
detected rotation caused by an external action is opposite to a
parameterized direction of rotation, resisting torque is
created.
4. A method as claimed in claim 1, wherein when the start-up
command is received, a limited torque to maintain switch-off is
created.
5. A method as claimed in claim 1, wherein the external action
comprises driving the thread and/or the drive device, said driving
being obtained manually by an operator or by auxiliary means.
6. A method as claimed in claim 1, wherein a start-up process of
the device comprises: a period during which the motor is kept
switched off; a period during which rotation is caused by an
external action; a period during which rotation is in accordance
with the pre-programmed acceleration profile; and a period of
operation at rated speed.
7. A method as claimed in claim 1, wherein the pre-programmed
acceleration profile comprises a linear ramp or ramp of any shape
whatsoever.
8. A method as claimed in claim 1, wherein: the pre-programmed
acceleration profile comprises a plateau of constant intermediate
speed that is different from a rated speed set point; and said
intermediate speed is pre-programmed or a rotation speed created by
the external action and measured briefly by the means after the
external action is detected.
9. A method as claimed in claim 8, wherein: a duration of the
plateau is pre-programmed; and the speed plateau is maintained
until the control unit receives an end-of "tracking" mode command
or command to change to normal operating mode via an input/output
or over a network.
10. A method as claimed in claim 3, wherein the torque is limited
during execution of an acceleration phase.
11. A method as claimed in claim 10, wherein the limiting of the
torque is fixed and depends on the rotation speed.
12. A method as claimed in claim 10, wherein torque limiting is
maintained for a pre-programmed time until the speed reaches a
speed of an intermediate speed plateau; or until an end of the
intermediate speed plateau; or until the speed reaches a rated
speed set point; or until the control unit receives an end-of
"tracking" mode command or command to change to normal operating
mode via an input/output or over a network.
13. Apparatus for using the method according to claim 1, comprising
several thread drive devices, at lease one thread drive device
being slaved to a motor associated with a control unit capable of
receiving a speed signal, wherein the motor is a
variable-reluctance or permanent-magnet motor, a power supply
sequence of the motor comprises a sequence for switching power
supplies of motor windings synchronized by signals representative
of position of a rotor relative to a stator of the motor, said
signals being sent to a processor in order to measure and detect
the rotation speed of the at least one thread drive device.
14. Apparatus as claimed in claim 13, wherein the signals
representative of the position of the rotor relative to the stator
are used by the processor in order to determine direction of
rotation of the at least one device.
15. Apparatus for using the method as claimed in claim 12, wherein
the several drive devices cooperate with each other in order to
drive a single thread.
16. Apparatus as claimed in claim 15, wherein each drive device has
an individual start-up tracking mode, sensors that output signals
representative of device rotation speed and means of waiting for
rotation caused by an external action in order to accelerate in
accordance with a respective acceleration profile.
17. Apparatus as claimed in claim 15, wherein only one device of
the drive devices has an individual start-up tracking mode, and
further comprising a control system programmed to keep speed ratios
of other devices constant relative to said one device that has the
tracking mode, means of measuring rotation speed of the one device,
and the speed ratios being predetermined by parameter
adjustment.
18. A device as claimed in claim 17, wherein detection of the speed
caused by an external action, management of acceleration profiles
and, execution of the tracking sequence are performed by a program
executed by a central processing unit and/or the control unit.
19. The method of claim 3, wherein the resisting torque is
parameterized and/or monitored by voltage or current limiting.
Description
[0001] The invention relates to the technical field of
installations or machinery for processing continuous elongated
materials moved by transport along their own trajectory. Such
continuous elongated materials include textile threads, ribbons,
tapes, etc.
[0002] More especially, the invention relates to the control of
means for transporting the material capable of feeding it along its
own trajectory. Such means include, by way of information and
merely by way of example, cylinders, pulleys, endless belts,
rollers, godet rolls or other devices that transport the elongated
material by friction, gripping, meshing etc.
[0003] Various technical solutions have been proposed for starting
up machinery intended for processing elongated materials or other
thread-like products. Based on the prior art, a distinction is
essentially made between two solutions.
[0004] With the first solution (JP-A-52091912), the material is
previously laid out along the transport route while the transport
devices are switched off. This operation is referred to as
"threading" in the case of machinery for processing textile
threads. The transport devices are then switched on and gradually
accelerated until they reach the required rated speed, depending on
the work to be performed. Generally speaking, acceleration is
programmed in accordance with synchronised ramp rates which
maintain constant speed ratios. This solution makes it necessary to
use synchronised means of starting and stopping. This solution
cannot be used with certain devices such as those used in heat
treatment which are likely to burn the material if it is static,
given the fact that the material is not moving when start-up is
initiated.
[0005] In contrast to this solution, another method involves
starting the material transport devices in advance, running them up
to their rated speed and then feeding in said material. The
material is only fed into the input of the transport devices once
the rated speed has been reached so that the material is snatched
and instantly transported at rated speed. Generally speaking, the
material is presented by a device that moves it at an initial speed
that is close to the rated speed of the treatment process. For
example, this device may consist of arms associated with suction
nozzles such as those widely used on textile machinery.
[0006] This solution is nevertheless difficult to use in the case
of high-speed processes involving fragile materials that cannot
withstand the rapid acceleration encountered, generally speaking,
when the material is snatched.
[0007] If this operation is performed manually, it requires great
dexterity on the part of the operator.
[0008] It should also be noted that there are safety problems,
given that operations are performed on moving parts.
[0009] Finally, there have been proposals to combine the two
threading technical solutions explained above in some complex
installations (U.S. Pat. No. 3,842,578). For example, threading is
performed only on some of the switched-off devices, avoiding
thermal devices, for instance, which cannot process material that
is stationary. The installation is then started and run up to rated
speed, transferring the moving material to the devices that were
avoided during initial threading.
[0010] In this case too, the solution is relatively tricky to
implement.
[0011] The invention has set itself the object of overcoming these
drawbacks in a simple, dependable, effective and efficient
manner.
[0012] The problem that the invention aims to solve is to control
the devices used to transport thread-like products such as textile
yarns, ribbons and tapes along their own trajectory during the
start-up phase.
[0013] According to the invention, a method for control of linear
drive devices for a thread-like product, in particular a textile
thread, during the start-up phase has been devised, each of said
devices being slaved to an electric motor, the motor being
associated with at least one control unit capable of receiving
speed and/or speed ratio set points and start/stop commands.
[0014] According to the invention, given the problem to be solved:
[0015] the device control unit is subjected to a means of measuring
the speed of said device; [0016] on receiving a start-up command,
start-up of the motor is not initiated if the measured speed is
zero; [0017] information representative of the measured speed of
the drive device is monitored; [0018] a control sequence which
brings about rotation of the motor in accordance with a
pre-programmed acceleration profile is initiated when rotation
caused by an external action is detected.
[0019] As a result of the basic characteristics of the invention,
start-up mode can only be initiated if the motor is initially
switched off. Changeover to this operating mode does not initiate
the sequence to control the motor so as to cause immediate rotation
of the latter in accordance with an acceleration profile. On the
contrary, according to the invention, changeover to this operating
mode may, if the technology of the motor so permits, cause creation
of a limited torque to maintain switch-off. This torque may be
parameterisable and monitored by voltage or current limiting for
example.
[0020] The motor is kept switched off as long as rotation caused by
an external action is not detected.
[0021] When rotation caused by an external action is detected, the
control sequence which brings about rotation of the motor in
accordance with a programmed acceleration profile is initiated.
[0022] In one preferred embodiment of the invention, when rotation
caused by an external action is detected, information
representative of the direction of rotation of the drive device is
monitored and the control sequence which brings about rotation of
the motor is initiated only if the direction of rotation matches a
previously parameterised direction of rotation. If a non-matching
direction of rotation is detected, the system may, if the
technology of the motor so permits, cause creation of a resisting
torque; this torque may be parameterisable and/or monitored by
voltage or current limiting for example.
[0023] After receiving a start-up command, the process comprises:
[0024] a period during which the motor is kept switched off; [0025]
a period during which rotation is caused by an external action;
[0026] a period during which rotation is in accordance with the
acceleration profile; [0027] a period of operation at rated
speed.
[0028] According to the invention, the external action consists of
driving the thread and/or the drive or transport device for said
thread, said driving being obtained manually by an operator or by
auxiliary means.
[0029] The acceleration profile is a linear ramp or a ramp of any
shape whatsoever.
[0030] According to the invention, the acceleration profile may
comprise a constant intermediate speed plateau that is different
from the rated speed set point: [0031] The intermediate speed of
the plateau can be pre-programmed. [0032] The intermediate speed of
the plateau can be the rotation speed created by the external
action and measured briefly by the control system after it is
detected. [0033] The duration of this plateau can be
pre-programmed. [0034] The speed plateau can be maintained until
the control system receives an acceleration command via an
input/output or over the network.
[0035] According to the invention, this control sequence determines
(motor or brake) torque limiting monitored, for instance, by
voltage or current limiting: [0036] This torque limiting can be
fixed. [0037] This torque limiting can depend on the rotation
speed. [0038] This torque limiting can be maintained for a
pre-programmed time. [0039] This torque limiting can be maintained
until the speed reaches the speed of the intermediate speed
plateau. [0040] This torque limiting can be maintained until the
end of the intermediate speed plateau. [0041] This torque limiting
can be maintained until the speed reaches the rated speed set
point.
[0042] In order to use the method according to the invention, the
device comprises thread transport devices slaved to at least one
control unit capable of receiving at least one speed signal, the
motor being a variable-reluctance or permanent-magnet motor, the
power supply sequence of which is a sequence for switching the
power supplies of its windings synchronised by signals
representative of the position of the rotor relative to the stator,
said signals being capable of being used in order to measure and
detect the rotation speed.
[0043] The motor may be also be an induction or other type of
motor.
[0044] According to the invention, the device to transport a
thread-like material may comprise several components that act
together in combination.
[0045] In this case, each transport device has an individual
start-up tracking mode, sensors that output signals representative
of its speed and means of waiting for rotation caused by an
external action in order to accelerate in accordance with its own
acceleration profile.
[0046] Alternatively, only one of the transport devices has an
individual start-up tracking mode and the control system is
programmed to keep the speed ratios of the other device(s) constant
relative to said device that has the tracking mode, which is a
means of measuring its rotation speed, the speed ratio(s) being
predetermined by parameter adjustment.
[0047] Detection of the speed caused by an external action,
management of acceleration profiles and, more generally, execution
of the tracking sequence are performed by a program executed by a
central processing unit and/or the processor.
[0048] The invention is explained below in greater detail,
reference being made to the accompanying drawings in which:
[0049] FIG. 1 shows an example of an embodiment of the method for
control of transport of a thread-like product associated with a
control unit;
[0050] FIG. 2 is a curve showing an example of an acceleration
profile;
[0051] FIG. 3 is a curve showing an example of an acceleration
profile with a pre-programmed speed plateau;
[0052] FIG. 4 is a curve showing an example of an acceleration
profile with a speed plateau equal to the speed resulting from an
external action.
[0053] In each of FIGS. 2, 3 and 4: [0054] (A) is the period during
which the device waits to be rotated: [0055] (B) shows the period
during which rotation is caused by an external action (if
applicable, broken down into detection period (B1) and speed
measurement (B2)); [0056] (C) is equivalent to the period during
which rotation is in accordance with the acceleration profile (if
applicable, broken down into acceleration phase and speed plateaux
(C1), (C2), (C3), etc.); [0057] (D) is equivalent to the period of
operation at rated speed.
[0058] FIG. 1 shows an example of a transport device (1) in the
form, for example, of a godet roll capable of driving a thread-like
product such as, for instance, a textile thread. Device (1) is
driven by electric motor (2) slaved to a control unit (3) that is
connected to an electric power supply (4). Control unit (3)
comprises, for example, a power supply (5), power circuitry (7) and
a processor (6) slaved to a central processing unit (9) in the form
of, for instance, a PC, automaton or printed circuit board, etc.
Means (8) are capable of delivering a signal representative of the
rotation speed of transport devices (1).
[0059] According to the invention, processor (6) receives speed or
speed ratio set points from central processing unit (9) over
network (10) as well as the operating parameters of transport
devices (1) controlled by motors (2). If applicable, processor (6)
may receive start, stop, etc. commands via the network or via other
inputs/outputs.
[0060] The control unit (3) of electric motors (2) receives
information representative of the speed of means (1) that
transports the thread-like product.
[0061] According to one basic aspect of the invention, at least one
of the transport devices is subjected to a particular start-up mode
characterised by the following essential arrangements: [0062] this
start-up mode is initiated when the motor is initially switched
off; [0063] changeover to the operating mode does not initiate a
sequence to control the motor so as to cause immediate rotation of
the latter in accordance with an acceleration profile and may, if
applicable and if the technology of the motor so permits, cause
creation of a limited torque to maintain switch-off; [0064] the
control unit monitors the information representative of the speed
(phase (A)) of the transport devices so that switch-off (and if
applicable, the limited torque to maintain switch-off) is
maintained as long as rotation resulting from an external action is
not detected.
[0065] This external action may consist of driving the thread
and/or device (1) (phase B), it being possible to obtain said
driving manually by the operator or by any auxiliary means.
[0066] When external action is detected, control unit (3) initiates
a sequence to control motor (2) (phase (C)) in accordance with a
pre-programmed acceleration profile.
[0067] According to one enhancement of the invention, information
representative of the direction of rotation of drive device (1) is
available, for example, in association with information
representative of the speed of said drive device. When rotation
caused by an external action is detected, control unit (3) checks
the direction of this rotation and only initiates the control
sequence which brings about rotation of motor (2) if the direction
of rotation matches a parameterised direction of rotation.
[0068] If a non-matching direction of rotation is detected, control
unit (3) may, if the technology of the motor so permits, cause
creation of a resisting torque; this torque may be parameterisable
and/or monitored by voltage or current limiting for example.
[0069] In FIGS. 2, 3 and 4 which show various examples of speed
curves, (A) is the period during which the motor is kept switched
off, (B) is the period during which rotation is caused by an
external action, (C) is the period during which rotation is in
accordance with the acceleration profile and (D) is the period of
operation at rated speed.
[0070] In these curves, (11) represents a rated set-point speed and
(12) represents acceleration along a linear ramp (FIGS. 2 and 4) or
several ramps (12a), (12b) (FIG. 3). As shown in FIGS. 3 and 4, the
acceleration profile may include a plateau (13, 14) at a constant
intermediate speed that is different from the rated set-point speed
(11). The intermediate speed of the plateau can pre-programmed or
be the rotation speed created by the external action and measured
briefly by the control system after it is detected. The duration of
the speed plateau can be pre-programmed and its speed can be
maintained until the control unit receives an acceleration
command.
[0071] Note that, when the control sequence determines a torque
monitored, for example, by voltage or current limiting, the torque
can be fixed or can depend on the rotation speed and be maintained
for a pre-programmed time or until the speed reaches the plateau
speed and the intermediate speed or it can be maintained until the
end of the intermediate speed plateau or be maintained until the
speed reaches the rated-speed set point.
[0072] If motor (2) is a variable-reluctance or permanent-magnet
motor, the power supply sequence is a sequence for switching the
power supplies of the windings synchronised by signals
representative of the position of the rotor relative to the stator
(Hall-effect sensors) or sensors for measuring the current in the
windings that are representative of the position of the rotor
relative to the stator. The signals obtained from these sensors can
be used by processor (6) in order to detect and measure the
rotation speed.
[0073] The signals obtained from these sensors can also be used to
determine the direction of rotation of the motor.
[0074] According to the invention, the device to drive the
thread-like material may comprise several transport components,
each driven by a motor (2).
[0075] In this case, either each transport device (1) has an
individual start-up tracking mode or only one of the transport
devices (1) has an individual start-up tracking mode.
[0076] If each transport device has an individual start-up tracking
mode, each of the devices has sensors outputting signals
representative of these speeds. Each device will wait to be rotated
by an external action in order to accelerate according to its own
acceleration profile.
[0077] If only one of the transport devices has an individual
start-up and tracking mode, the control system is pre-programmed to
keep the speed ratios of the motor(s) that does/do not have an
individual start-up tracking mode constant relative to the motor
that does have such a mode.
[0078] The motor equipped with an individual start-up tracking mode
is fitted with sensors or means of measuring its rotation speed
with the speed ratio(s) being predetermined by parameter
adjustment. In this way it is possible to control all the motors by
controlling the speed of the motor(s) that does/do not have an
individual start-up tracking mode in synchronism or by tracking the
speed of the motor that does have such a mode.
[0079] Note that the device uses a program capable of ensuring
detection of the speed caused by an external action, management of
acceleration profiles and, generally speaking, execution of the
tracking sequence as described. Note that these various functions
can be performed by a program executed by processor (6) of control
unit(s) (3) or by a combination of central processing unit (9) and
processor (6) (FIG. 1).
[0080] The advantages of the invention are readily apparent from
the description, the following features in particular being
emphasised and underlined: [0081] the operator can initiate
transport by making a single movement completely safely by causing
rotation when required, [0082] start-up can be gradual without any
sudden transition at the instant the thread is applied to the drive
device.
* * * * *