WO2021028753A1

WO2021028753A1 - Control system and method for managing sewing machines

Info

Publication number: WO2021028753A1
Application number: PCT/IB2020/057073
Authority: WO
Inventors: Thomas Ambrosi
Original assignee: Tor.Mec Ambrosi S.R.L.
Priority date: 2019-08-09
Filing date: 2020-07-27
Publication date: 2021-02-18
Also published as: IT201900014475A1

Abstract

An electronic unit (3) of a control system (1) for managing sewing machines (2) is placed operatively in contact with a sewing machine (2). The electronic unit (3) comprises a detection module (5) configured to detect vibration data related to the vibrations induced by the sewing machine (2). The vibration data detected are associated with a univocal identification code (X1, X2, X3,...), which univocally identifies the electronic unit (3) and the sewing machine (2). A vibration curve (C) is generated which comprises the vibration data detected by the detection module (5) as a function of the time (t). The operating module (8) is configured to identify in the vibration curve (C) an elementary curve (E) characteristic of the sewing machine (2), which is saved in a storage module (9). The operating module (8) is configured to compare the vibration curve (C) with a characteristic elementary curve (E) saved in the storage module (9).

Description

“Control system and method for managing sewing machines”

Technical Field

The present invention relates to a control system and a method for managing sewing machines.

Furthermore, the present invention relates to a system for producing sewed items.

In the sector there is a particularly felt need to be able to manage sewing machines in order to optimise their operation. For this purpose it is necessary to know the machine status, in particular whether the machine is active or on standby.

Prior art

There are known sewing machines of an electronic type which are designed and built from the start with integrated electronic cards for setting and implementing the sewing functions. These are sewing machines that have an electric power supply characterised by the presence of electric input and output signals which cause the machine itself to switch on and off. In some known systems, the electronic unit is capable of detecting such electric signals so as to have a clear indication of which mode the machine is in (active/standby).

In the sector of systems for producing sewed items, however, there is still a large number of sewing machines of a traditional type, which cannot be economically converted so as to be able to detect the above-mentioned electric input and output signals. Indeed, in some cases it is not rare to find sewing machines of an exclusively mechanical type, which thus do not have the aforesaid electric input and output signals necessary to be able to detect which mode the machine is in. Hence, in the sector there is a particularly felt need to be able to manage every machine and possibly the operator associated therewith irrespective of the type of sewing machine used.

In particular, also in the sector of systems for producing sewed items, a need is being felt to apply the so-called Internet of Things (loT), that is, the possibility of communication between “things” understood as apparatus, devices and equipment. Unfortunately, this possibility of communication is at present limited to sewing machines of a more advanced type.

Object of the invention

In this context, the technical task at the basis of the present invention is to provide a control system and a method for managing sewing machines which enables such needs to be satisfied in a simple and economical manner.

In particular, it is an object of the present invention to provide a control system and a method for managing sewing machines which is capable of connecting together sewing machines of any type, including a completely mechanical type, preferably in a common data analysis environment.

A further object of the present invention is to provide a control system and a method for managing sewing machines that is easy to apply and reliable and does not require excessive investments.

The stated technical task and specified objects are substantially achieved by a control system and a method for managing sewing machines, respectively comprising the technical features disclosed in one or more of the appended claims.

In particular, the present invention relates to a control system and a method for managing sewing machines, and in particular for managing the production data of the machines themselves, based on the detection of the vibrations induced by the machine during operation. This detection is carried out by means of an electronic unit which is applied to or rested upon the machine from the outside so as to generate a first management environment. The electronic unit does not need to interact with the operation of the machine itself and can be used with any sewing machine. The vibrations detected are univocally associated with the electronic unit and with the sewing machine through a univocal identification code, in order to be able to generate a vibration curve univocally associated with the machine.

This makes it possible to have objective data that can be used for statistical and control purposes.

The present invention can comprise one or more of the features specified in the dependent claims, incorporated herein by reference, each corresponding to a possible embodiment.

In accordance with a first example, a reference curve characteristic of the sewing machine is identified in the vibration curve and is then saved in a storage module so as to establish a database useful for controlling machines having identical or similar configurations.

In accordance with a second example, starting from a pre-established database it is possible to check whether the operation of the machine shows any anomalies by comparing its vibration curve with a characteristic reference curve it should exhibit.

Furthermore, using a communication module in proximity it is possible to generate a second management environment comprising the first management environment and the operator who is performing a function on the machine (sewing, maintenance, repair, setting, ....), thereby obtaining further objective data that can be used for statistical purposes and for the purpose of controlling the system for producing sewed items. Additional features and advantages of the present invention will become more apparent from the approximate and thus non-limiting description of a preferred but non-exclusive embodiment of a control system and a method for managing sewing machines.

Brief description of the fiqures This description will be set out below with reference to the appended drawings, which are provided solely for illustrative and therefore non limiting purposes, in which:

- figure 1 schematically illustrates a control system for managing sewing machines in a system for producing sewed items;

- figure 2 schematically illustrates a vibration curve that represents vibration data related to the vibrations induced by the sewing machine as a function of time.

Description of one or more preferred embodiments of the present invention

With reference to the appended figures, 1 indicates a control system for managing sewing machines adapted for the implementation of a method for managing sewing machines.

With reference to figure 1 , the reference number 2 indicates the sewing machines that can be managed by means of the control system 1. In general, a sewing machine can be dedicated to a specific function, for example the function of sewing pockets or the function of sewing waistbands or other functions. Alternatively, sewing machines with generic and/or variable functions can be provided for, based on the different needs.

A system for producing sewed items 100 comprises at least one sewing machine 2 and the control system 1. The sewing machines 2 illustrated in figure 1 belong to the same system for producing sewed items 100. Alternatively, the control system 1 can manage a plurality of sewing machines 2 of different systems for producing sewed items.

The control system 1 comprises an electronic unit 3, preferably defined by an electronic card. The electronic unit 3 is placed operatively in contact with each sewing machine 2, preferably by means of a connection portion 4 of the electronic unit itself, suitable for the purpose.

The operative contact between the electronic unit 3 and the sewing machine 2 is of a mechanical type and does not necessarily require a connection of an electrical type. In this case, the electronic unit 3 is provided with a power supply means, for example a battery and/or systems for recovering energy by means of piezoelectric crystals or power cables adapted to be connected to the mains electricity. Alternatively, the electronic unit 3 can be provided with an electrical connection means for connecting to a power supply means of the sewing machine 2.

The connection portion 4 can be created by means of an outer surface of the electronic unit 3 adapted to be placed resting on the sewing machine 2 or on a rest surface “A” of the sewing machine 2 in order to ensure the transmission of the vibrations to the unit 3 or to a sensor connected to the unit. Alternatively, suitable coupling means can be provided to mechanically connect the electronic unit 3 to the sewing machine 2 or to the rest surface “A” of the sewing machine 2.

The electronic unit 3 comprises a detection module 5 configured to detect vibration data related to the vibrations induced by the sewing machine 2. In particular, the detection module 5 comprises at least one vibration sensor, not illustrated, preferably selected from among electronic components such as gyroscopes, accelerometers, acoustic components and/or others not expressly mentioned here.

In accordance with a possible embodiment, the detection module 5 can be further configured to detect data related to at least one or more parameters, selected, for example, from among temperature, humidity, position, air composition and sound/noise. In particular, the detection module 5 can comprise at least one temperature sensor and/or at least one humidity sensor and/or at least one position sensor (for example GPS) and/or a sound/noise sensor and/or other types of sensors.

In particular, the electronic unit 3 can also comprise GSM modules, preferably with a connection to a mobile network (e.g. 3/4/5 G, NB-loT with the use of a SIM card or eSIM) or other LPWAN wireless technologies, such as, for example, Wifi™, ZigBee®, Bluetooth®, LoRa® or LoRaWAN™.

The reference number 6 indicates an identification module configured to univocally identify the electronic unit 3 and the sewing machine 2 through a univocal identification code X1 , X2, X3, ....

The univocal identification code comprises a univocal machine identification code and a univocal unit identification code.

The univocal machine identification code consists, for example, of one or more of: type of sewing machine, model of sewing machine, serial number of the sewing machine and function of the sewing machine. The univocal machine identification code preferably comprises all of the aforesaid data. Furthermore, the identification code is preferably assigned automatically by means of a suitable algorithm and communication protocol.

The unique unit identification code can consist of the physical address of the unit, for example the MAC address.

It is preferable for the identification module 6 to be integrated into the electronic unit 3, as illustrated, for example, in figure 1 , though other embodiments are possible, for example ones in which the identification module is integrated into the sewing machine 2 or is located in a position remote from the latter.

It is further preferable for the identification module 6 to comprise an interface 7 configured for the entry of at least the univocal machine identification code. In this manner, if the identification module 6 is integrated into the electronic unit 3, the univocal machine identification code entered via the interface 7 is automatically associated with the univocal unit identification code in order to obtain the univocal identification code. Alternatively, the interface 7 can also be used for the entry of the univocal unit identification code.

Preferably, but not necessarily, the control system 1 (and preferably the electronic unit 3) can comprise a module having one or more connectors for connecting external elements (e.g. cables, “whips” of external sensors or other types of detectors) to pick up clean signals. The reference number 8 indicates an operating module. It is preferable for the operating module 8 to be integrated into the electronic unit 3, as illustrated, for example, in figure 1 , though other embodiments are possible, for example ones in which the operating module is located in a position remote from the latter.

The reference number 9 indicates a storage module 9 and the reference number 10 indicates a communication module.

The communication module 10 is operatively interposed between the detection module 5 and the operating module 8 so as to generate a first management environment. In other words, the first management environment comprises the sewing machine 2, the detection module 5 and the operating module 8 or, preferably, the sewing machine 2 and the electronic unit 3.

The operating module 8 is configured to associate with the univocal identification code the vibration data detected by the detection module 5. The operating module 8 is further configured to generate a vibration curve “C” comprising the vibration data detected by the detection module 5 as a function of the time t. A possible vibration curve “C” is illustrated with a continuous line in figure 2.

The vibration curve “C” of a sewing machine 2 preferably, but not exclusively, exhibits an approximated sinusoidal pattern because of the fact that needle is usually (but not always) driven by means of a crank/connecting rod. Furthermore, depending on the specific functions of the sewing machine 2, the vibration curve “C” can exhibit peaks “P”, which are generated in concomitance with the activation of further devices such as, for example, pneumatic cylinders.

It has advantageously been found that both the shape of the sinusoid and the presence and position of the peaks constitute a unique characteristic of the sewing machine 2, and in particular of the type, model, brand and function. Furthermore, it has advantageously been found that in the vibration curve “C” it is possible to identify a characteristic reference curve Έ” which represents a modulus that repeats itself in a substantially identical manner during the normal operation of the sewing machine 2 to which the electronic unit 3 has been applied and during the normal operation of any other sewing machine of the same type, the same model and having the same function. The characteristic reference curve Έ” univocally identifies the type, model and function of a sewing machine. A possible characteristic reference curve Έ” has been illustrated in figure 2 with a broken line.

In accordance with a first embodiment, the operating module 8 is further configured to identify the reference curve Έ” characteristic of the sewing machine within the vibration curve “C”. This step is preferably defined as the sampling step.

The reference curve Έ” is then saved in the storage module 9 placed in communication with the operating module 8 via the communication module 10. In particular, the communication module 10 is operatively interposed between the detection module 5, the operating module 8 and the storage module 9.

In accordance with what is illustrated in figure 1 , the storage module 9 is at least partially remote from the sewing machine 2 and the electronic unit 3. Preferably, and in particular in this case in which the storage module 9 is remote from the sewing machine 2, the communication module 10 comprises a wireless module, for example Wifi™ or Bluetooth® or GSM, preferably with a connection to the 3/4/5G network, or Zigbee® or NB- loT™ or LoRa® or LoRaWAN™ or a wired connection module.

Optionally, the storage module 9 can be at least partially integrated into the electronic unit 3.

In accordance with a second embodiment, which can be cumulative with or alternative to the first embodiment described above, the reference curve Έ” characteristic of the sewing machine 2 being available, the operating module 8 is configured to compare the vibration curve “C” with that characteristic reference curve Έ”. Furthermore, the operating module 8 is configured to verify whether the pattern of the vibration curve C diverges from or follows the pattern of the reference curve Έ”, taking account of a certain minimal divergence to be defined and negligible.

The operating module 8 can preferably be configured to generate a correction signal in the event that the vibration curve “C” diverges from characteristic reference curve Έ” and in the event that the electronic unit 3 is connected (via a cable or wirelessly) to the control system of the sewing machine 2 (obviously, having a sewing machine that allows this to be done). For example, the correction signal can be used by the operating module itself to directly control the sewing machine. In other words, upon detecting a divergence between the vibration curve “C” and the characteristic reference curve Έ”, the operating module 8 automatically intervenes on the sewing machine 2 to restore correct operation so as to eliminate the aforesaid divergence. In addition or alternatively, the correction signal can be used to generate a warning, for example an audible and/or visual and/or computer warning, such as to require or schedule an intervention of an operator assigned to maintain, set or repair the sewing machine 2.

The characteristic reference curve Έ” with which the comparison is made can be the one previously detected for the same sewing machine 2 and saved in the storage module 9. In other words, after the reference curve Έ” characteristic of the sewing machine 2 has been identified, it is used as a basis for comparison in order to monitor the subsequent operation of the sewing machine 2 over time. If the operating module 8 is configured to generate the correction signal, said correction signal is used during the regular operation of the sewing machine 2 in order to eliminate malfunctions.

The characteristic reference curve Έ” with which the comparison is made can be a characteristic reference curve Έ” previously detected for another sewing machine of the same type and the same model and performing the same function. In other words, the basis for comparison can already be available in the storage module 9, enabling the operation of the sewing machine 2 to be monitored starting from its installation, thus both during the setting-up phase and during regular operation. If the operating module 8 is configured to generate the correction signal, said correction signal can thus be used not only during regular operation but also during the machine setting-up phase in order to reduce setting times and enable the regular operation of the sewing machine itself to begin earlier.

At the same time it should be noted that the reference curve Έ” is also a function of the temperature, humidity, sounds/noise ... detected by the sensors of the electronic unit 3. Therefore, the reference curve Έ” could be different also for sewing machines 2 of the same type (for example because they operate under different temperature/humidity conditions). Therefore, the control system 1 is of the adaptive type in order to have the possibility of learning and determining, by means of specific algorithms, the appropriate times for carrying out maintenance activities or adjustments of the environmental conditions where the machines and workers operate (optimisation of the environment).

Considering there being a plurality of sewing machines 2 available, in each of the embodiments described it is possible to place an electronic unit 3 operatively in contact with each sewing machine. The control system 1 can thus comprise a plurality of electronic cards 3, each electronic unit being associable with a sewing machine belonging to one or more systems for the production of sewed items. In this case it is preferable for the storage module 9 to be at least partially located remotely from the electronic unit 3 and for the communication module 10 to comprise a wireless or cable-connected module.

Subsequently, it will then be possible to univocally identify every electronic unit 3 and the respective sewing machine 2 by means of the respective univocal identification code and to detect the vibration data related to the vibrations induced by each sewing machine 2 by associating the univocal identification code to the vibration data detected. Finally, it will be possible to generate, for each sewing machine 2, a respective vibration curve “C” comprising the vibration data detected as a function of time.

In accordance with the first embodiment described above, starting from each vibration curve “C” it is possible to identify the respective characteristic elementary curves Έ”. By saving such characteristic elementary curves Έ” in the storage module 9, one thus obtains a database of characteristic elementary curves Έ” in which each characteristic reference curve Έ” is associated with a univocal identification code X1 , X2, X3.

In addition to this, as already illustrated above, each elementary curve Έ” has a dimensional level that depends on the environmental variables detected, such as temperature, humidity, sound/noise or others.

In accordance with the second embodiment described above, it is possible to compare the characteristic elementary curves Έ” detected with respective characteristic elementary curves Έ” previously saved in the storage module 9 and having the same univocal identification code. The database available in the storage module 9 can relate to the sewing machines on which a comparison is being made or to sewing machines of the same type and the same model or brand and performing the same function.

In accordance with a possible embodiment, the control system 1 comprises a communication module in proximity 11, for example RFID or NFC, having a reading antenna 12, preferably associated with the electronic unit 3, and a passive electronic label 13, preferably associable with an operator “O” univocally identifiable by means of a univocal operator identification code. The passive electronic label 13 associable with an operator “O” can be produced as an actual label, a badge, a bracelet, or in another form.

When the operator moves near the electronic unit 3, the sewing machine 2 is associated with the univocal operator identification code by means of the communication module in proximity 11. In this manner a second management environment is generated, comprising the first management environment and the operator. In other words, when the operator moves near the sewing machine 2, the univocal identification code also comprises the univocal operator identification code, so the operating module 8 associates the vibration data detected also with the operator.

If the operator is assigned to operate the machine, i.e. assigned to sewing, being able to have the vibration curve “C” of the sewing machine 2 associated with the respective operator, it is possible to obtain statistical data on the production and times of each operator in order to optimise the operations to be performed within the same system.

If the operator is assigned to the maintenance and/or repair of the machine, being able to have the vibration curve “C” of the sewing machine 2 associated with the respective operator, it is possible to obtain statistical data on the intervention and the maintenance/repair times.

In accordance with a possible embodiment, the electronic unit 3 can comprise a button, non illustrated, or other signalling means that the operator to sewing can use to request the intervention of further operators, for example operators assigned to maintain, repair and set the sewing machine.

In detail, the electronic unit 3 is configured to pick up input signals by means of the detection module 5 or other modules specially connected to unit itself; the input signals are processed and associated with an event or call or generation of another executable signal.

Such input signals are for example representative of “gestures” of the operator (for example when an operator knocks on the bench of the sewing machine 2 with his/her a hand or claps his/her hands, etc.) which are processed by the electronic unit 3 and generate specific events or signals directed towards the outside of the sewing machine 2 itself. Furthermore, by means of the control system 1 , it is possible to implement a method for managing sewing machines in which the electronic unit 3 is placed operatively in contact with a sewing machine 2. The electronic unit 3 and the sewing machine 2 are univocally identified by means of the univocal identification code.

The vibration data related to the vibrations induced by the sewing machine 2 are thus detected and the vibration data detected are associated with the unique identification code. The vibration curve “C” comprising the vibration data detected as a function of time is then generated.

Within the vibration curve “C” it is possible to identify the reference curve Έ” characteristic of the sewing machine 2 so as to save it in the storage module 9.

The vibration curve “C” can be compared with a characteristic reference curve Έ” previously saved.

The optional detection of further parameters such as temperature, humidity, position, sound/noise or others enables a further control based on the environmental situation the sewing machine is in. For example, it is possible to signal whether the working conditions are outside of the ranges provided for.

Optionally, it is possible to associate the sewing machine with the univocal operator identification code, so that the univocal identification code also comprises the univocal operator identification code. In this manner the performance of the second environment is verified and it is possible to know the times of activity and inactivity of the machine associated with the operator. These data are particularly significant, since the time in which an operator handles or moves the items being sewed on sewing machines is equal to about 80% of the cycle time, that is, the time necessary to perform the function for which the machine was configured The use of RFID systems or the like does not impact production, being automatic.

The present invention enables the collection of a number of data sufficient to create a comprehensive system, at a low cost, which can be applied to any sewing machine, also a pre-existing one that may be completely mechanical (for example pedal-operated). The present invention thus makes it possible to extend the concept of the Internet of Things also to the sewing machine sector irrespective of the type of machine.

The generation of a vibration curve “C” provides statistical data related to downtimes and work times and the collection of such data not only does not interfere with production, but it also allows the latter to be optimised both in terms of managing timely, predictive maintenance interventions and in terms of managing operators.

The creation and/or use of a database comprising the characteristic elementary curves Έ” makes it possible to accelerate machine setting times and allows the operation of the machine themselves to be controlled over time.

Claims

1. A control system (1) for managing sewing machines (2), said control system (1) comprising: an electronic unit (3) having at least one connection portion (4) adapted to be placed operatively in contact with a respective sewing machine (2), wherein said electronic unit (3) comprises a detection module (5) configured to detect, by contact, vibration data related to the vibrations induced by the sewing machine (2), an identification module (6) configured to univocally identify said electronic unit (3) and said sewing machine (2) through a univocal identification code (X1. X2, X3, ), an operating module (8) configured to associate with said univocal identification code (X1 , X2, X3, ...) the vibration data detected, a communication module (10) operatively interposed between the detection module (5) and the operating module (8) so as to generate a first management environment, characterised in that said operating module (8) is configured to: generate a vibration curve (C) comprising the vibration data detected by the detection module (5) as a function of the time (t); compare the vibration curve (C) with a reference curve (E) characteristic of said sewing machine (2) having said univocal identification code (X1 , X2, X3, ...) identified by means of said electronic unit (3); verify whether the pattern of the vibration curve (C) substantially diverges from or substantially follows the pattern of the reference curve (E).

2. The control system (1) according to claim 1, wherein the operating module (8) is configured to sample said vibration curve (C) so as to identify said reference curve (E) characteristic of the sewing machine (2), wherein the control system (1) comprises a storage module (9) adapted to save said reference curve (E) characteristic of the sewing machine (2), and wherein the communication module (10) is operatively interposed between the detection module (5), the operating module (8) and the storage module (9).

3. The control system (1) according to claim 1, comprising a storage module (9) in which at least one reference curve (E) characteristic of the sewing machine (2) and identified through said univocal identification code (X1 , X2, X3, ...) is pre-saved, wherein the communication module (10) is operatively interposed between the detection module (5), the operating module (8) and the storage module (10).

4. The control system (1) according to claim 3, wherein the operating module (8) is configured to generate an error signal in the event that the vibration curve (C) diverges from the characteristic reference curve (E).

5. The control system (1) according to claim 4, wherein the operating module is configured to control the sewing machine (2) on the basis of said error signal.

6. The control system (1) according to one or more of claims 2 to 5, wherein the storage module (9) is arranged at least partially remotely with respect to the electronic unit (3), wherein preferably the communication module (10) comprises a wireless module, preferably Wifi™ or Bluetooth® or GSM or other wireless technologies such as LPWAN™ or Zigbee® or NB-loT™ or LoRa® or LoRaWAN™, and wherein the control system (1) preferably comprises a plurality of electronic cards (3) each associable with a sewing machine (2) of one or more systems for producing sewed items (100).

7. The control system (1) according to one or more of claims 2 to 6, wherein the storage module (9) is at least partially arranged in the electronic unit (3).

8. The control system (1) according to one or more of the preceding claims, wherein the identification module (6) is arranged in the electronic unit (3) and comprises an interface (7) configured for the entry of a univocal machine identification code, for example comprising the type, model, serial number and function of the sewing machine, and for associating said univocal machine identification code with a univocal unit identification code to form said univocal identification code (X1 , X2, X3, ...).

9. The control system (1) according to one or more of the preceding claims, wherein said detection module (5) is configured to detect data related to at least one further magnitude, e.g. selected from temperature, humidity, position, sound/noise.

10. The control system (1) according to one or more of the preceding claims, comprising a proximity communication module (11) having a reading antenna (12) preferably associated with the electronic unit (3), and a passive electronic label (13), preferably associable with an operator (O), so as to generate a second management environment comprising the first management environment and said operator (O) associated with a univocal operator identification code, and wherein said univocal identification code (X1 , X2, X3, ...) comprises said univocal operator identification code.

11. A system for producing sewed items (100) comprising: at least one sewing machine (2) and a control system (1) according to one or more of the preceding claims, wherein said electronic unit (3) is placed operatively in contact with the sewing machine (2).

12. A system for producing sewed items (100) according to claim 11 , wherein said at least one sewing machine (2) comprises a workbench defining a rest surface (A) and said electronic unit (3) is arranged in contact with said rest surface (A) so that said detection module (5) detects, by contact with said workbench, the vibration data related to the vibrations induced by the sewing machine (2) on said workbench.

13. A system for producing sewed items (100) according to claim 11 or 12, wherein said electronic unit (3) is removable with respect to the sewing machine (2).

14. A method for managing sewing machines (2), comprising the steps of: arranging an electronic unit (3) operatively in contact with a sewing machine (2), wherein said electronic unit (3) comprises a detection module (5) configured to detect vibration data related to the vibrations induced by the sewing machine (2), univocally identifying said electronic unit (3) and said sewing machine (2) through a univocal identification code (X1 , X2, X3, ...), detecting vibration data related to the vibrations induced by the sewing machine (2), associating with said univocal identification code (X1, X2, X3, ...) the vibration data detected, and generating a vibration curve (C) comprising the vibration data detected as a function of the time (t); characterised in that said operating module (8) is configured to: generate a vibration curve (C) comprising the vibration data detected by the detection module as a function of the time (t); compare the vibration curve (C) with a reference curve (E) characteristic of said sewing machine (2) having said univocal identification code (X1 , X2, X3, ...) identified by means of said electronic unit (3); verify whether the pattern of the vibration curve (C) substantially diverges from or substantially follows the pattern of the reference curve (E).

15. The method for managing sewing machines according to claim 14, comprising the steps of: sampling said vibration curve (C) so as to identify said reference curve (E) characteristic of the sewing machine (2), saving said reference curve (E) characteristic of the sewing machine (2).

16. The method for managing sewing machines according to claim 14 or 15, comprising the step of comparing the vibration curve (C) with a characteristic reference curve (E) previously saved.

17. The method for managing sewing machines according to one or more of claims 14 to 16, comprising a step of associating said sewing machine (2) with a univocal operator identification code, said univocal identification code (X1 , X2, X3, ...) comprising said univocal operator identification code.