Method for Controlling an Attending Device of a Workstation of a Yarn Manufacturing Textile Machine, and a Textile Machine

Abstract

A method is provided for controlling movement and operation of an attending device of a yarn manufacturing textile machine, wherein the attending device moves along a row of workstations arranged next to each other to perform operations at the workstations. The method controls the movement of the attending device along the work stations and operations of the attending device based on success statistics of the operations at the workstations to achieve an overall increased efficiency of the textile machine. An operational stay of the attending device at a particular one of the work stations is terminated without waiting for a result of the operation being performed by the attending device at the particular workstation.

Claims

1-10. (canceled)

11. A method for controlling movement and operation of an attending device of a yarn manufacturing textile machine, wherein the attending device moves along a row of workstations arranged next to each other to perform operations at the workstations, comprising: controlling the movement of the attending device along the work stations and operations of the attending device based on success statistics of the operations at the workstations to achieve an overall increased efficiency of the textile machine; and terminating an operating stay of the attending device at a particular one of the work stations without waiting for a result of the operation being performed by the attending device at the particular workstation.

12. The method according to claim 11, wherein the operating stay of the attending device at the particular work station is terminated after the attending device performs a predetermined number of attempts to successfully complete the operation.

13. The method according to claim 12, wherein the predetermined number of attempts is individualized for each of the workstations.

14. The method according to claim 13, characterized in that the predetermined number of attempts is determined for each of the work stations based on the success statistics of the operations at the workstations.

15. The method according to claim 14, wherein the success statistics of the operations at the workstations are updated after each attempt performed to complete the operation.

16. The method according to claim 11, wherein the operating stay of the attending device at the particular work station is terminated before the attending device performs a predetermined number of attempts to successfully complete the operation after a determination that performing one of the operations at another workstation will lead to improved efficiency of the textile machine, whereupon the attending device moves to the other workstation and performs one of the operations at the other workstation.

17. The method according to claim 16, wherein upon terminating the operating stay of the attending device at the particular work station, the attending device passes a yarn formed at the particular work station to means at the particular workstation,

18. The method according to claim 17, wherein upon terminating the operating stay of the attending device at the particular work station, the particular work station is flagged for one or more subsequent actions of: checking for successful performance of the operation; completion of the operation by subsequent arrival of the attending device or another attending device; and completion of the operation by the means at the particular work station.

19. The method according to any of claim 17, wherein the means at the particular workstation hold the yarn for completing the operation at a later stage.

Description

DETAILED DESCRIPTION

[0017] The invention will be described with reference to an example of a method for controlling an attending device of a yarn manufacturing textile machine.

[0018] The yarn manufacturing textile machine comprises at least one row of identical workstations arranged next to each other. The workstation is well known per se, and therefore, for the sake of completeness, it will be described only symbolically without a picture. Each workstation comprises a spinning unit in which yarn is formed. Above the spinning unit, a draw-off mechanism of yarn is provided, which comprises a known pair of draw-off rollers, between which the yarn passes to a winding device which winds the produced yarn on a bobbin. The yarn winding device comprises a yarn traversing device, by which the yarn is traversed across the bobbin width.

[0019] In addition, the workstation may have its own complete or partial handling means for resuming the production activity at the workstation after previous interruption of this activity, for example after the doffing of a wound bobbin, after shutting down the whole yarn manufacturing textile machine or its section, or after a yarn break, etc.

[0020] The machine further comprises at least one attending device, which is movable back and forth along at least one row of workstations and which is provided with means for performing attending operations at the individual workstations, such as detecting the broken yarn end on a yarn package, inserting an empty tube in a winding device, spinning-in yarn (onto auxiliary yarn, on the spinning-in end of broken yarn), etc. The attending device is further provided with a control unit which is coupled to the control unit of the yarn manufacturing textile machine and to the control unit of the workstation or a section of the yarn manufacturing textile machine.

[0021] The attending device and/or the workstation are further provided with means for terminating the working activity and/or the presence of the attending device at the workstation before the planned termination of working activity and/or presence at the respective workstation.

[0022] The control unit of a yarn manufacturing textile machine continuously monitors and evaluates numerous pre-determined production-related parameters using a mathematical model, such as the success rate of the attending attempts of the individual attending device at the individual workstations. The control unit shall, upon receipt of another request for an attending operation from a particular workstation, decide to which position in the sequence of workstations waiting to be operated, the respective workstation will be assigned, or will decide to mark the workstation as inoperable. If the control unit decides to assign to the workstation a position in the sequence of the workstations waiting for the attending operation, then the maximum number of attempts to perform the attending operation is adaptively adjusted according to the mathematical model for the particular workstation and for the particular attending device.

[0023] If there are more attending devices, then the statistics are also monitored with respect to the success rate of the individual attending devices at the individual workstations, and according to the statistics, the individual attending devices are assigned to individual workstations and in the corresponding order.

[0024] The sequence of the workstations to be attended to changes adaptively. If a new request for an attending operation comes from a workstation which has, for example, considerably better success statistics of the attending operations or which has, for example, significantly better statistics of success of the attending operations or, for example, has a higher working capacity per unit of time, then it is preferred in the sequence of the workstations waiting for the attending operation.

[0025] In addition, the control unit has the maximum number of attempts to perform successfully the attending operations at the workstation set for all workstations, hereinafter referred to as the maximum number of attempts. This maximum number of attempts is fixed and set for each workstation of the entire machine. The maximum number of attempts indicates the maximum possible number of unsuccessful attempts of the attending device to perform an attending operation at each particular machine workstation before this particular workstation is marked as error and the attending device, after performing the maximum number of attempts, leaves the particular workstation regardless of the result of the last attempt, including situations when the workstation has not been attended to.

[0026] The invention is based on the concept that each workstation has different parameters, however slight the differences may be, and therefore the success rate of the performed attending operations is different, too. If, according to the statistical success of operations at specific workstations of the machine, the individual success rate of each workstation is monitored, it is possible to determine and set the current maximum number of attempts of the attending device for each workstation to successfully carry out attending operations at a particular workstation, hereinafter only the current maximum number of attempts. The value of the current maximum number of attempts, therefore, describes the real statistical success of the attending operations performed at the particular workstation, whereby this value is less than the maximum number of attempts. This means that, according to the present invention, the attending device performs at each workstation only as many unsuccessful attempts to perform an attending operation as may be determined from the statistics of the actual success rate of the attending operations at the particular workstation, but the number of unsuccessful attempts must not be higher than the maximum number of attempts. It is assumed that if a specific workstation is statistically less successful in carrying out attending operations, the probability that the given attending operation will be successful with more than the actual (real) statistical number of attempts is small. Therefore, if the attending device operates at a specific workstation which has a certain statistically determined current maximum number of attempts, and there is another workstation requiring an attending operation on the machine, this other workstation having a lower value of the current maximum number of attempts, the control unit will make a decision on the basis of these current values and on the basis of any other parameters that allow to observe and determine the overall efficiency of the entire machine (distance between the two workstations, speed of the movement of the attending device, the success rate of the attending operation at the other workstation, the performance of the particular workstation, the working time of the particular workstation, etc.), about premature termination of the attending operation at the workstation statistically worse (which is being currently attended to). The decision is made already (even) before the maximum number of attempts has been exhausted, and the attending device goes to the statistically more advantageous workstation, whereas the workstation which has been attended to up to now, but is statistically worse, remains unattended or continues the attending operation with the assistance of its own means.

[0027] Premature termination of attending operations at a statistically worse workstation is carried out according to one embodiment in such a manner that the attending device completes its active activities at the workstation and passes the yarn to the means of the workstation to a defined position, and afterwards leaves the workstation waiting for further attending operations.

[0028] According to another embodiment, the premature termination of attending operations at a statistically worse workstation is carried out by the attending device completing its active activities at the workstation, passing the yarn to the means of the workstation, and without waiting for the successful completion of all attending operations at that workstation by the means of the workstation, this attending device moves over to a statistically better (more advantageous) workstation on which the attending operation starts. In the meantime, the means at the original, statistically worse, workstation finish the attending operations without the attending device being present at this workstation, and according to the success rate of the completion of the attending operation, the workstation either resumes its production activity, or this statistically worse workstation waits for further attending operations.

[0029] Taking into account the movement of the attending device between the individual workstations, it is also the length of the time interval (distance) for moving the attending device from its current working position to the workstation requesting an attending operation that is considered, wherein the workstation with a shorter time interval (a shorter distance) is attended to preferably.

[0030] The control unit controls the operation and interoperability of the attending devices and workstations using the mathematical model of the machine which takes into account selected production-related and quality parameters, as well as their possible interaction and combinations, in order to achieve the greatest possible production efficiency of the whole yarn making textile machine during its manufacturing activity and to determine the operation of the attending devices and their possible interaction with partial or complete handling means of the workstation. In determination of the sequence of the workstations to be operated, a workstation with a higher amount of yarn produced per unit of time, etc., is preferred, i.e. the parameter of the highest achievable efficiency of the machine as a whole is applied. Similarly, account is also taken of the fact that the particular workstation is operated by a particular attending device with a higher or lower success rate than when operated by another attending device, etc.

[0031] The invention can be used in the operation of yarn manufacturing textile machines provided with attending devices for yarn manufacturing textile machines.

[0032] Modifications and variations can be made to the embodiments illustrated or described herein without departing from the scope and spirit of the invention as set forth in the appended claims.