KR20090008471A - Method and apparatus for identifying two ends of an article to each other - Google Patents

Abstract

generating a curve (PF) which approximates the profile of one end (P) of an article; processing said curve to determine whether it approximates the profile of said first or said second end.

Description

METHOD AND DEVICE TO DISCRIMINATE TWO ENDS OF AN ARTICLE FROM EACH OTHER}

The present invention relates to improvements in methods and apparatus for handling articles having longitudinal extensions and two different ends, for example tubular knitted articles, in particular stockings or socks.

More specifically, the present invention is particularly useful for detecting and identifying new ends, such as distinguishing or identifying two ends of the same article that differ in shape from one another, such as but not exclusively, such as socks or stockings or other tubular knitted articles. It is about a new device.

<Technology status>

In the manufacture of stockings and socks, the use of automation of the manufacturing process tends to increase gradually, from knitting the articles to sewing the toes.

In this tendency towards automation, one of the most critical aspects is such as a sock carried from a circular knitting machine with a toe portion opened and placed randomly in a container for continuous and automatic handling of the article in a sewing machine, It is represented by the difficulty in automatically detecting which of the two ends of the tubular article is the band portion and which is the toe portion.

Often these operations are performed by hand. The operator picks up each semifinished product from the container, such as a basket, and the semifinished product coming from the knitting machine is placed randomly with the toe end still open, ie not yet sewn or connected. The operator then inserts the semifinished product onto the conveying tube oriented in the correct direction, ie to the position required by the machinery downstream, and automatically sews or connects the toes.

That is, attempts have been made to solve the problem of automatic detection, which distinguishes the elastic band end portion and the toe portion of the semifinished knitted fabric. For example, US Pat. No. 5,040,475 discloses a complicated machine for picking up each tubular article from a container in which the tubular article is placed randomly. By causing the article to follow a special treatment passage, the detection means first detects the orientation of the tubular article along the supply passage and confirms whether the article is oriented with the toe portion or elastic band end facing forward along the passage. . After detecting this, the tubular article is placed in an intermediate station and conveyed in one or the opposite direction as a function of the orientation in which the tubular article is inserted into the station.

JP-A-7468502 and JP-A-1272801 disclose other devices for handling tubular articles, such as stockings or socks, to properly orient the tubular articles.

US-A-6719577 discloses an apparatus for longitudinally orienting each tubular article coming from a container in which a tubular article is randomly placed. ,

EP-A-1221502 picks up each sock or other tubular article from a container in which the tubular article is placed randomly, and then one side of the end of the tubular article is oriented so that it is always the leading end by a special pneumatic passage, Disclosed is an apparatus using a detection system that can distinguish the ends of an elastic band from the toe portion of an article through the different stretching properties of the fabric.

US-A-5769286 discloses a spreading device for longitudinally unfolding a sock or tubular knitted fabric.

EP-A-178143 discloses another system for detecting orientation of tubular textile articles by identifying stretchable band ends and toe portions.

US-A-5511501 discloses a complex method of picking up each tubular article from a container in which a tubular article is placed randomly, and separating the tubular article so that each tubular article is placed in each smaller container. The machine is disclosed. Each article is then picked up from each smaller container, inserted into a special pneumatic passageway, within which the tubular article is oriented and always transported from the pneumatic passageway in the same orientation.

US-A-5884822 discloses another apparatus and method for picking up each tubular article from a container.

US-A-5992712 discloses another device for picking up each tubular knitted piece and orienting the tubular knitted piece appropriately.

Similar problems with the orientation of tubular articles can be found in feeding stockings or socks into a setting machine. For example, in the manufacture of women's stockings, there is a problem in inserting each single stocking on the setting board, with the toe portion already sewn, and for this purpose, the stocking to insert the stocking on the board. Each stocking should be picked up from this randomly placed container.

Presently known methods and apparatus for automatically identifying the first and second ends of an article, such as tubular knitted articles, are particularly unreliable and expensive.

Purpose and Summary of the Invention

It is an object of embodiments of the present invention to provide a method and apparatus for automatically identifying two ends of an article that are to be detected, for example having ends that are different in shape from one another. According to a particular aspect, it is an object of the present invention to provide a method and apparatus for identifying and detecting the toe portion or elastic band end of a sock or stocking.

In the present description, it is frequently mentioned that there is still a need to detect the toe portion of the sock to be sewn, but the teachings of the present invention, for example, accurately align the article or place a packaging machine or the like before placing it on the setting plate. It is also to be understood that it may also be applied where the orientation of an already sewn article has to be detected in order to perform further operations required in the manufacturing and / or packaging cycles of the present invention.

 Indeed, in an embodiment of the invention, for example, generating a curve approximating one profile of the end; A method of identifying a first end and a second end of an elongated article, comprising processing the curve to detect whether the first or second end is close to the profile.

Indeed, according to this aspect of the invention, that is, one indicated by the reading sensor provides for the generation by means of a curved point approximating the actual profile of one of the two ends of the article. Based on the shape of this approximation curve, whether this end is the first or second of the two ends characterized by substantially different profiles from each other, such as, for example, the toe portion of the sock and the elastic band end generally It is a device that can be detected.

According to an aspect of an embodiment of the invention, the points of the approximate curve are each characterized by two coordinates in the reference system, although it is possible to use a different reference system, but preferably it can be a Cartesian reference system and when the article has a generally flat shape , Preferably two-dimensional.

Indeed, in a possible embodiment, there is provided an arrangement of photovoltaic cells, arranged along a straight line, and a method of moving the articles with respect to each other, for example, to progressively block the beam of photovoltaic cells to the ends of the articles. Based on the relative position taken by the article and the photovoltaic cell and the electrical signal produced by the gradual blocking of the light beam of the photovoltaic cell, it is determined that the plurality of points are located above the profile approximating the profile of the end of the article. When the profiles of the two ends are different from each other, the slopes of the profiles reconstructed by the approximation point are also different from each other. By processing a curve approximating these profiles, the two ends can be identified from each other.

According to a preferred embodiment, the method comprises the steps of: arranging a plurality of photovoltaic cells according to a predetermined arrangement; Moving the arrangement of the article and the photovoltaic cell with respect to each other along a relative direction of movement such that one end of the article blocks the beam of the photovoltaic cell during relative movement; Determining coordinates of a plurality of points belonging to the profile of the end of the article blocking the beam, based on the arrangement of the photocell and the relative position taken by the article with respect to the photocell during reciprocating movement. to provide.

Preferably, in an embodiment of the invention, each time a photovoltaic cell is blocked by the article during the relative movement, the article and the photovoltaic cell are detected and the direction of relative movement forming a coordinate of a point belonging to the profile. The reciprocating position between the photovoltaic cell and the article and the position of the blocked photocell are detected.

A curve approximating the profile of the end of the article blocking the photovoltaic cell can be generated by inserting points belonging to the profile of the end, for example, by linear interpolation. While not absolutely necessary, it is also possible to obtain a high-order polynomial polynomial. The approximation through the segments of the straight line where the various points identified on the profile of the end of the article join together is always sufficiently accurate. Therefore, in the present specification and the appended claims, the curve is also generally intended as a dashed line, for example obtained from a portion of a continuous straight line to which points identified on the profile of the end of the article join.

In a possible embodiment of the method according to the invention, a curve approximating the profile of the end of the article read by the photovoltaic cell is processed to determine the inclination of the inclination, wherein the first and second ends of the article are inclined. And are detected as a function of this slope. For example, this results from the continuity of the portion of straight lines that the points identified on the end profile join. The derivative can also be calculated by means of points, and therefore, more schematically, is constructed by dashed lines resembling the slope of the derivative.

In a particularly simple embodiment, although accurate in many cases, the maximum and minimum values of the derivative are determined and the difference is calculated. Two ends of the article are detected and identified, for example, based on a comparison between the threshold and the maximum and minimum of the derivative. This is, for example, in the case of a sock, since the toe part has a very high variable curvature, and the toe part also has a slope with derivatives that take significantly different values from one another along the extension of the profile representing the end, Instead most of the band ends are usually surrounded by a straight line, so the derivative is possible due to the fact that they have a flat slope.

According to another aspect, the present invention relates to a device for identifying each other, for example, as a function of the arrangement of the sensor that recognizes a plurality of points belonging to the profile of the end of the article and as a function of the coordinates of the points, An apparatus for identifying each other with first and second ends of an article, comprising a control unit and a processing unit, for detecting whether it belongs to the first end or the second end.

In practice, the control unit and the processing unit can be programmed to generate a curve approximating the profile of the end as a function of the points identified by the sensor.

According to a preferred embodiment of the invention, the sensor consists of an array of photovoltaic cells and, together with a system for detecting a reciprocating position between the product and the photovoltaic cell, places the arrangement and the article of the photovoltaic cell in a direction of relative movement. Thus, it also provides a handling member that moves relative to each other. Processing with the control unit to determine a plurality of points that join the position of the photocell blocked by the article during the relative movement between the article and the photovoltaic cell in a position state each time taken by the article with respect to the photovoltaic cell along the direction of relative movement. The unit can be programmed.

The array of photovoltaic cells can be of various types. Preferably, they are arranged along a linear string of photovoltaic cells. Preferably, such strings of photovoltaic cells are arranged along an alignment orthogonal to the direction of said relative movement. In this way a series of points in the Cartesian coordinate system are obtained simply by translating the article and the array of photovoltaic cells with respect to each other.

Preferably, the control and processing unit is configured such that whenever a photocell is blocked by the article during the relative movement, the relative position between the article and the photovoltaic cell is detected and forms coordinates of the points belonging to the profile. Along the direction, the reciprocating position between the article and the photocell and the position of the blocked photocell are detected.

Other preferred features and implementations of the method and apparatus according to the invention are disclosed in the appended claims, which are described in more detail below in terms of non-limiting possible implementations of the invention.

The invention is better understood by the following description and the accompanying drawings, which disclose practical non-limiting embodiments of the invention.

1 shows a diagram of the device from the front;

FIG. 2 is a cross-sectional view taken along II-II of FIG. 1. FIG.

3A-3D schematically illustrate the continuity of movement of an article, such as a stocking or sock, wherein the toe portion is positioned facing the light reading system.

4 shows a diagram of the profile of the derivative and the toe portion of the article.

5A-5B schematically illustrate the continuity of movement of an article positioned with the band end facing the light reading system.

6 shows a diagram of the derivative and the profile of the band end.

FIG. 7 schematically illustrates a different processing method of identifying the first end of the article and the second end of the article based on the slope of the curve approximating the profile of the end of the article by the sensor of the device.

8 and 9 show another embodiment of the method according to the invention.

10A and 10B illustrate a modified embodiment of the invention.

Detailed Description of the Preferred Embodiments of the Invention

1 and 2 are very schematic views of the device according to the invention. (1) indicates the support surface of the article M, and in the illustrated embodiment, the article is a sock having a toe portion P to be sewn and an elastic band end B. FIG.

On the support surface 1, which can be constituted by a conveyor or the like, a movable element 3 is arranged, such as a compactor, which is formed by translational movement along the two-way arrow fo and up and down movement fv. The compactor 3 is moved along the two-way arrow fv by the piston-cylinder actuator 5 and is alternately done by a slide 7 sliding in a guide (not shown). The movement along the fo of the slide 7 along the guide is controlled by a belt 9 driven near two pulleys 11 and 13, the second being motorized by a motor 15. do. Reference numeral 17 denotes an encoder or other angular transducer which allows the movement of the motor 15 to be detected and consequently the movement of the slide 7 along the bidirectional arrow fo. Instead of the encoder in combination with the motor 15, any other means can be used to directly detect the movement of the slide 7 or even the movement of the compactor 3. This detection means (encoder 17 in this example) is connected with a programmable control unit, indicated by 19, which is connected to the interface with the monitor 19 or other user interface. The control unit 19 may be provided as a general unit of a keypad and other peripherals and a programmable controller suitable for controlling the device.

21 denotes a system of photovoltaic cells consisting of a linear array of photoemitters and a linear array of photoreceivers, the two arrays being parallel and facing each other. In the figure, reference numeral 23 denotes a first array of the above-mentioned arrays, for example, an array of photo emitters, while reference numeral 25 denotes an array of opposing arrays, for example, photo receivers. As will be apparent from the following description of the two operating cycles, one or the other of the end of the article is directed towards the detection or reading device 21, with the article M being translated and the end blocking the photocell, And to block the beam of photovoltaic cells to said end to detect whether it is a band end B or toe portion P. FIG.

In general, when the two ends P of the article M have different profiles from one another, the article M is progressively retained with the ends of the article under the linear array of photovoltaic cells of the reading system 21. By supplying the following data, namely the position in space of the photovoltaic cell; Signal of each photovoltaic cell; Using the position of the presser 3 along the direction of movement fo and consequently the position of the article along the feeding direction along the arrow F, the shape of the profile of the end can be read and detected.

3A-3D and 4 illustrate the detection of the toe portion P of the article M. FIGS. This figure shows the four relative positions of the toe portion P with respect to the array of photovoltaic cells 21, represented by (X 1-X 8) in these diagrams. In the example, eight emitter receiver pairs are shown, but it should be understood that different numbers of photovoltaic cells may be used. The number is dictated by the demand for price and sufficient detection accuracy. In the position of FIG. 3A, none of the photovoltaic cells are blocked by the toe portion P of the article. In FIG. 3B, the photocell X4 is blocked, but at the position of FIG. 3C, the positions X3 to X6 of the photocell are blocked. In FIG. 3D, the positions X2 to X7 of the photovoltaic cell are blocked.

The positions X1 to X8 of the photovoltaic cell indicate the number of values corresponding to the axes of the abscissa of the Cartesian diagram reproduced in FIG. 4, but are determined by the encoder 17 in engagement with the motor 15. Indicates the ordinate. By reproducing the coordinates corresponding to the photovoltaic cells blocked for each individual value of Y (position of the article) on the diagrams X, Y (Fig. 4) in the abscissa, one set of points P1-P6 is obtained, They are inserted to generally form the profile (PF) of the end of the article. More specifically, the point P4 is formed by the coordinates on the axis of the abscissa x formed by the coordinate Y0 and the position (first blocked first) of the photovoltaic cell X4 (FIG. 3B). It is not necessary to know the absolute value of the coordinate Y0 on the axis of the ordinate and, as important, the position of the coordinate on the axis of the continuous point of the profile. As the article M is advanced, the position photocells X3 and X5 are blocked at the value of the ordinate Y1, and then the photocell X6 is blocked at the ordinate Y2 (FIG. 3C), finally. , Photocell X7 is blocked at ordinate Y3 (FIG. 3D). In this way, the point of the profile PF is obtained. The value of the ordinate Y0 can be taken as a value of zero, and the subsequent ordinate is determined by the compactor 3 and thus on the basis of the relative movement performed by the article M.

The same occurs when the end read by the array of photovoltaic cells is a band end. This case is schematically shown in Figs. 5A and 5B, and Fig. 6 shows the curve PF obtained by appropriately inserting the points identified by the coordinates X and Y thus determined. The points on the diagram are again represented by (P1) to (P6).

It can be seen that the diagrams PF of FIGS. 4 and 6 have very different shapes in both cases. In particular, it can be seen that the insertion curve of FIG. 4 has very much variable slope with respect to the curve of FIG. After generating the insertion curve, the derivative can be calculated with any suitable criteria. The slope of the derivative (reproduced again for the two cases in the diagrams of FIGS. 4 and 6 and represented by (D)) indicates the change in the slope of the curve, and therefore the larger of the profile PF detected by the photovoltaic cell. Or smaller curvature.

Derivatives can be used to detect, ie, distinguish the toe portion from the band end, for example, via a simple criterion of comparison with a threshold. In practice, for example, it is possible to simply determine the maximum and minimum values of the derivatives and calculate the difference. The difference in value can be compared with an experimentally determined threshold. If the difference in values exceeds the threshold, this is an indication of the curved profile and as a result confirms the toe part, but if the difference in values does not exceed the threshold, this is an indication of a flat profile and consequently the band end Check.

Experimentally, it is easy to identify the threshold, which indicates that the difference between the maximum and minimum values of the derivatives is below and above the threshold for the band end (B) profile and toe portion (P) profile of the article. Do.

7 schematically illustrates a different embodiment of the invention. Indeed, in this case, the apparatus is substantially as described with reference to FIGS. 1 and 2. According to this method, the points P1-Pn belonging to the profile of the end of the article, for example read by the sensors configured by the photovoltaic cells 23, 25, are also substantially the same. Conversely, according to this method, the data representing the points belonging to the approximation curve are processed changes.

7A shows a Cartesian reference system, the abscissa and ordinate of which are denoted by X and Y, respectively. P1 to P5 indicate the points belonging to the profile of the end of the article M. In this embodiment, five points are shown, however, it should be understood that the number of points may vary based on the shape of the article and the shape of the system (as in the previous embodiment).

In this embodiment, the curve on which points P1 to P5 lie is inclined with respect to coordinate X-Y. This means that the article is not in a straight position but reaches the photovoltaic cells 23 and 25 in an inclined position. This embodiment includes a preliminary step for processing the detected data to correct the error. In fact, the curve at which points P1-P5 lie is reproduced in the X'-Y 'reference system rotated by an angle α, and the straight line X' of its abscissa is somewhat perpendicular to the axis of the article, and consequently, the end points P1, Pass through P5. If the difference between the abscissa and the ordinate of the point P5 and the ordinate and the ordinate of the point P1 is represented by (a) and (b), therefore,

α = arctan (b / a)

The equation for converting the coordinates of the points P1-P5 from system X-Y to system X'-Y ',

X '= Xcos (-α)-Ysin (-α)

Y '= Xsin (-α) + Ycos (-α)

Fig. 7B shows a curve obtained by the insertion method of the points P1-P5 in the reference system X'-Y ', where the coordinates are placed in the horizontal and vertical positions, respectively. This preliminary motion (and consequently the insertion curve of the points belonging to the profile) for correcting the slope of the approximation curve of the profile of the end of the article can also be done as a preliminary step in the embodiment disclosed with reference to FIGS. 3 to 6. have.

Once the curve is reproduced at the reference system X'-Y ', the difference between the maximum and minimum values of the ordinates of points P1-P5, denoted by ΔY' in FIG. 7B, can be determined. The two ends (toe part P and the band end part B) of the article M are characterized by different profiles by the degree of curvature, and the value ΔY 'of the difference in the ordinates is with respect to the two ends. It is quite different. FIG. 7B reproduces a curve approximating the band end B of the article in dashed lines, and ΔC represents a comparative value determined experimentally based on an analysis of the shape of the appropriate number of ends of the article. At every end of the article ΔY '> ΔC' is classified as a "toe portion" and at every end of the article ΔY'≤ΔC 'may be classified as a "band end".

8A and 8B disclose an improved process or method for identifying between the toe portion and the band end, for example when the article is positioned with a particularly high tilt relative to the direction of movement, the end profile (band end or By the side of the article rather than by the toe portion) to prevent discrimination due to blocking of the photocell.

8A and 8B, B denotes the band end of the article M, F0, F1... FN denote the same number of photovoltaic cells as N + 1, and X, Y or X ', Y 'Denotes a Cartesian reference axis with respect to which the coordinates of the points belonging to the profile of the end (toe part or band end) of the article M blocking the photoelectrons are identified (the system X and Y represent the alignment and photovoltaic cells of the photocell). System X 'Y', with respect to axis X, in accordance with the rotational criteria disclosed with reference to the previous embodiment, but with the last point of the profile considered for identification and The line that joins the first point is rotated by an angle corresponding to the angle of the tilt).

8A and 8B represent the article (such as socks) from the side of the band end while passing through the front side of the photovoltaic cell slightly inclined with respect to the direction of relative movement, represented by arrow F. FIG. The amount of movement H, i.e. the relative movement of the article with respect to the photovoltaic cell is predetermined, and the article moves forward by this amount irrespective of the number of photocells effectively blocked at the end of this movement. The amount of movement H must be sufficient to pass through the profile of the band end B of the inclined article (angle β in the figure) and to prevent the large number of photocells from blocking the side of the article in the case of the inclined article. prevent. The amount H is determined experimentally based on the type of article.

As can be readily understood by observing in FIG. 8A, in order for the analysis not to be distorted, all points of the profile blocked by the photocell are taken into account, as the point of blocking the photocell as indicated by F8 results in a distorted signal. But it is wise to discard the two end points.

To discard both the first and last points of the profile, the algorithm described below can be used. To understand the following, the first photovoltaic cell is assigned input 0 of a PLC or other programmable control unit and the corresponding captured ordinate is Y0; In the sense that the second photovoltaic cell is assigned input 1 and the ordinate is Y1, and thus reaches the end, the input N is assigned and the ordinate is YN, the variable contained in the calculated value is equal to 0 before starting the detection operation. It is necessary to mention that, in order from 0 to N, where the number of photovoltaic cells is N + 1. Also, the second point of the profile blocked by the photovoltaic cell should be denoted by n1 and the second last point should be denoted by n2 respectively. This starts with the detection algorithm developing in the following steps.

Variable assignment

1) At the start of the procedure, all variables Yj and all pointers j and z are reset, where j is a pointer or counter associated with the photovoltaic cell (from 0 to N), z is the flag required for the correct execution of the algorithm, May take 0 optional variables 0 or 1,

2) After resetting the value of the variable, the relative movement between the photovoltaic cell and the article M is initiated. Since the distance between the article and the photovoltaic cell is not known in advance, the movement continues until the profile of the article blocks the first photocell, so there is a need for consideration.

3) At the first signal (blocking of the first photovoltaic cell by the article), the position Yj is captured (as described above with j = 0). This value is regarded as the value "0" of relative movement, in this sense the final value of the movement is set at this point. As H is the maximum travel distance between the interruption of relative movement between the article and the photovoltaic cell and the moment the blocking begins, consequently,

4) The position at which the motor supplying the article stops is determined equal to the sum Yj + H.

5) While moving from Y0 to Y0 + H, the blocking position (vertical coordinate Yi) of the profile is captured and stored. That is, during the relative movement equal to the movement distance H, the value of the relative movement corresponding to each single blocking signal of the photocell is collected,

6) The movement is stopped at position Y + H.

Definition of polygon approximating profile

The polygon is determined taking into account the coordinate point Yj excluding the first and last point to be blocked. Referring to Fig. 8A, the end points of the polygon to be considered are points n1 and n2 (second and previous second). The process of discarding the previous point n1 and the next point n2 is as follows.

7) Reading the ordinate Yj indicated by the pointer j

If Yj = 0 and z = 0, skip to step 8

If Yj> 0 and z = 0, skip to step 9

If Yj = 0 and z = 1, skip to step 9

If Yj> 0 and z = 1, skip to step 8

8) j = j + 1 and return to step 7

9) If z = 0, n1 = j + 1, z = z + 1, skip to step 8,

   If z = 1, n2 = j-1, skip to step 10.

At the end of the iteration, the points n1 and n2 are identified and consequently the polygon approximating the profile blocked by the photocell is given by the total of points n1, n2 and the midpoint. In a subsequent step, the analysis of the polygon is performed. Coordinates of the systems X and Y at points n1 and n2 are represented by Xn1, Yn1, Xn2, and Yn2, respectively.

10) A = arctan ((Yn2-Yn1) / ((Xn2-Xn1))

11) rotation of the coordinates (the equation already disclosed referring to the previous embodiment is applied)

12) Investigation of the minimum and maximum values of coordinate Y

13) Comparison with the value set to specify the type of profile: if the difference between the maximum and minimum values of ordinate Y 'is greater than the predetermined value, the blocked profile belongs to the toe part, otherwise the band end Belongs.

It is understood from the disclosed algorithm and FIG. 8 by discarding the first and last point identified by the passage of the profile of the article in front of the photovoltaic cell, for example in the case of FIG. 8, the identified end is not judged as the toe portion, In fact it is the band end. Due to the slope between the axis of the article and the direction of movement, this aberration can be derived from the blocking of the point n3 belonging to the side of the article by the photovoltaic cell F8.

In the embodiment described above, it is assumed that the article M is always positioned by the toe portion P which is positioned substantially flat in front, ie by an arc-shaped profile as shown in the figure. . However, this is not always the case, and in particular the toe portion P has an arc-shaped profile as shown in FIG. 2, for example, as it can be positioned on one side, depending on how the article is handled and flattened. It has a stepped profile with an approximately straight line region as shown in FIG. 9.

This means that if the amount of reciprocation (H) between the article (M) and the photovoltaic cell is less than or equal to the length (L), in this case both the toes and the band ends have different lengths but straight profile portions, which makes the analysis difficult. This results in a risk of false detection. On the other hand, in the case of an inclined article (angle β in FIG. 8), an excessive number of photovoltaic cells is prevented from being blocked by the side of the article rather than the end profile. The quantity (H) shall be limited.

Based on the difference between the maximum height and the minimum height with respect to the system of the reference signs (X ', Y') of the points in the profile, rather than using the aforementioned discrimination criteria, the toe portion is positioned as shown in FIG. The toe end is the number of photocells whose profile is blocked, since in the toe part they are certainly less than those contained in the band end, in order to avoid errors in making a distinction between the toe part and the band end when determined. It is determined from the band end by counting. Therefore, according to an improved embodiment of the method of the invention, after carrying out the movement of the class H between the article and the photovoltaic cell, first the total number of photovoltaic cells blocked by the profile of the article is determined. If this is less than the given minimum number, then the end that previously passed through the photocell is the toe portion. If the number of blocked photovoltaic cells is higher than the given minimum, then the disclosed identification process is performed based on the difference in the coordinates.

In conclusion, a more efficient system consists of both the reference of the rotation of the coordinates of the profile and therefore of the comparison between Ymax and the set value, taking into account the number of photocells blocking the profile.

In the disclosed embodiment, only one end of the article causes interaction with a photovoltaic cell or other sensor to recognize whether the end is the first or second end of the article. Once the end is recognized as the first end (eg the toe part), the other end is assumed to be the second end (eg the band end). However, this way of doing the method is not the only possible alternative. Indeed, that is, in an improved embodiment of the method according to the invention, in order to achieve reproducibility and a high degree of accuracy of the method or otherwise reduce the risk of misinterpretation of the detected data, the same article and one end Both of are detected by the same or two different sensor configurations.

In one possible embodiment, described below with reference to FIGS. 10A and 10B, the apparatus comprises a single linear array of photovoltaic cells 21. As described above, in the embodiment, the photovoltaic cell has an optical receiver 25 and an optical emitter 23 disposed on two sides of the intermediate position, where the article of manufacture M is to pass. However, in different embodiments (also applicable in the above-described embodiments), the photovoltaic cell may comprise an optical emitter on which the article M is placed, for example disposed on the reflective surface or on the same side of the conveyor. have.

Two handling members 5a and 5b are arranged one on each side of the photovoltaic device 21. In the embodiment, the members 5A and 5B are movable in the vertical direction along the bidirectional arrow fv and hang from the support structure schematically shown at 8. In the embodiment, the two handling members 5A, 5B each have endless belts 6A, 6B and are pulled near the rollers (three for each handling member in the example shown). At least one of the three roller clusters each is motorized but the other may not be used. The motorized rollers cause each belt 6A, 6B to move along a two-way arrow fo.

An article of manufacture (M) having a first end (i.e., toe end P) and a second end (i.e., band end (B)) moves under handling member 5A (5B). As in the previous embodiment, the orientation of the article M is random, i.e. it is not known in advance which is the toe portion and which is the band end. In the embodiment shown, the band end B is on the left side of the figure and the toe portion P is on the right side.

When the article M is placed under one or the other of the two members 5A and 5B, the member is lowered (arrow fv) so that at least one of the handling members contacts the article M so that the support surface ( Pressing it against 1), for example, the conveyor moves perpendicular to the drawing. One or both belts 6A and 6B are placed in a moving state in the same direction, for example, so that the article is pressed against the left side. During this movement one of the ends of the article passes between the surface 1 and the emitter 23, ie blocks the emitter receiver pairs 23, 25. In the example shown, in the position shown in FIG. 10A, the band end portion B just blocks the photovoltaic cell. Once this occurs, the device may determine, based on one of the modes disclosed above, whether the end just passed between the light emitter 23 and the optical receiver 25 is the first or second end. The movement of the belts 6A and 6B can be reversed or continued (depending on the starting position of the article) and also the second end passes through the photovoltaic cell 21. The apparatus determines whether the second end is a band end or a toe end and uses one of the methods disclosed above.

If the two readings match (i.e. in the example shown, the first readout determines whether the first detected end is the band end and the second detected end is the toe end), then the article M The orientation of is appropriately determined. However, if the readings do not match (ie if both ends are read as the toe ends or both ends are read with the band ends) then the control unit considers the reading to be aborted and discards the article. The article is in this case ie sent back to the basket which is picked up again for subsequent detection or to another container.

Aberrations (double-toe portion detection or double-band end detection) can be caused, ie if the article is not properly unfolded on the surface 1.

Even if a somewhat less reliable algorithm is used to identify the toe and band end portions, respectively, if both ends are read, the system reduces the possibility of error to a value that is truly negligible. Thus, a reliable system can actually be realized using a simple algorithm.

The drawings merely show examples purely presented as actual embodiments of the invention, and it should be understood that they can be varied in form and construction without departing from the scope of the concept underlying the invention. Any reference numerals in the appended claims are provided to facilitate reading of the claims with reference to the specification and drawings and do not limit the scope of protection represented by the claims.

Claims (44)

A first end and a second end have different profiles from each other, and wherein the first end and the second end of the stretched article are distinguished from each other. Generating at least one curve approximating at least one profile of said ends; Processing the curve to determine whether the first or second end is approximate to the profile of the first end and the second end of the stretched article. The method of claim 1, Moving the array of photovoltaic cells and the article with respect to each other; Progressively blocking the beam of photovoltaic cells to the ends of the article; Determining a plurality of points placed on the profile approximating the profile of the end of the article based on the relative position taken by the article and the photovoltaic cell and the electrical signal produced by the progressive blocking of the light beam of the photovoltaic cell. And identifying the second end and the second end of the stretched article from one another. The method according to claim 1 or 2, Arranging a plurality of photovoltaic cells according to a predetermined arrangement; Moving the arrangement of the article and photovoltaic cell with respect to each other along a direction of relative movement such that one end of the article blocks the beam of the photovoltaic cell during relative movement; Determining coordinates of a plurality of points belonging to the profile of the end of the article blocking the beam, based on the relative position taken by the article with respect to the photovoltaic cell during the reciprocating movement. And a first end and a second end of the stretched article. The method according to claim 2 or 3, Each time the photovoltaic cell is blocked by the article during the relative movement, a relative position is detected between the article and the photovoltaic cell and along the relative direction of movement between the photovoltaic cell and the article forming coordinates of a point belonging to the profile. Wherein a position and a reciprocating position of the blocked photovoltaic cell are detected. The method according to claim 2, 3 or 4, Generating the curve approximating a profile of the end of the article inserting at least some of the points belonging to the profile of the end, wherein the first and second ends of the stretched article are identified. Way. The method of claim 5 Wherein said point is inserted as a linear segment, wherein said first end and said second end of said stretched article are identified with each other. The method according to claim 5 or 6, And wherein said at least two end points identified above said profile are discarded. The method according to one or more of the preceding claims, The curve is processed to determine the inclination of the inclination, wherein the first and second ends of the article are identified with each other as a function of the inclination of the inclination. How to identify each other. The method according to one or more of the preceding claims, And the curve is reproduced in a coordinate system along with the axis on which the end point of the curve lies, identifying the first and second ends of the stretched article. The method according to one or more of the preceding claims, The difference between the maximum and minimum values of the coordinates of the curve is determined in a reference system, the difference forming a parameter for identifying the first end and the second end. And a second end to each other. The method of claim 10, The difference is compared with a predetermined value; And the end is recognized according to whether the difference is greater or less than the determined value. The method according to claim 10 or 11, wherein Determining coordinates of two points of the curve away from each other in a first reference system; Identifying a straight line joining the two points; Taking this straight coupling line as one of the coordinates of the second reference system rotated with respect to the first reference system; Determining said difference in said second reference system. The method of claim 12, The first and second reference systems are Cartesian reference systems, wherein the difference is expressed by the difference between the maximum and minimum values of the coordinates of the points of the curve along a reference axis perpendicular to the straight line. How to identify the first end and the second end to each other. The method according to claim 1, wherein at least one of: And a derivative of said curve is computed, wherein said first end and said second end of said stretched article are identified. The method of claim 14, And wherein the maximum and minimum values of the derivative are determined. The method of claim 15, The difference between the maximum and minimum values of the derivative is determined, and wherein the first and second ends are identified based on a comparison between the difference and the threshold. How to identify each other. The method according to one or more of the preceding claims, In order to block the beam of photovoltaic cells disposed in a fixed position, said article moves along a passageway and is taken as one of the ends of said article. The method according to one or more of the preceding claims, And the article is preconfigured with respect to the photovoltaic cell by a predetermined degree, irrespective of the number of blocked photovoltaic cells. The method according to one or more of the preceding claims, Determining a total number of photovoltaic cells blocked by the article after performing a predetermined movement (H) following the blocking of the first photovoltaic cell, comparing the total number with a predetermined minimum number, and comparing the first end of the article with the first end To identify the second end, wherein the first information further comprises the step of obtaining from the comparison. The method according to one or more of the preceding claims, And the article is a stocking or sock, wherein the first end and the second end of the stretched article are identified with one another. The method of claim 20, And wherein the first end is an elastic band end of the sock and the second end is a toe of the sock. The method according to one or more of the preceding claims, Both ends of the article of manufacture are detected and two curves are generated that approximate the profile of both ends; Both curves are processed to determine whether the first end and the second end of the stretched article are characterized in that the curve is processed to determine whether the first end approaches a profile of the second end. . An apparatus for identifying a first end and a second end of an article to each other, An array of sensors for identifying a plurality of points belonging to a profile of at least one end of the article, And a control and processing unit for detecting whether it belongs to the first end or the second end as a function of the coordinates of the point. The method of claim 23, wherein Wherein said control and processing unit is programmed to produce a curve approximating the profile of said end as a function of said point identified by said sensor. . The method of claim 23 or 24, The sensor consists of an array of photovoltaic cells, wherein along the direction of relative movement of the article and the array of photovoltaic cells, the handling members are configured to move relative to each other, and the system detects a reciprocating position between the article and the photovoltaic cell. And the first end and the second end of the article, characterized in that it is formed for. The method of claim 25, Determining the plurality of points that couple to the position of the photovoltaic cell blocked by the article during the relative movement between the article and the photovoltaic cell, with the position taken every time by the article with respect to the photovoltaic cell according to the direction of the relative movement. A device for identifying the first and second ends of the article, characterized in that the control and processing unit is programmed. The method of claim 25 or 26, And said array of photovoltaic cells consists of a linear sting of photovoltaic cells. The method of claim 27, And the sting of the photovoltaic cell is arranged along an alignment orthogonal to the direction of relative movement. The method of claim 25, wherein The control and processing unit is programmed so that the photovoltaic cell is blocked by the article every time during the relative movement, the relative movement between the article and the photovoltaic cell is detected, and between the photovoltaic cell and the article forming coordinates of the points belonging to the profile, And along the direction of relative movement, a reciprocating position and a position of the blocked photovoltaic cell are detected. The method of claim 23, wherein And said control and processing unit programmed to approximate a profile of said end of the article inserting at least some of said points belonging to said profile. The method of claim 30, Wherein said control and processing unit is programmed to insert said point through a linear segment. 32. The method of claim 30 or 31, Wherein said control and processing unit is programmed to discard the first and last of said point. 33. The method of claim 23, wherein The control and processing unit is programmed to determine the slope of the slope of the curve generated through the point identified by the sensor, wherein the first and second ends of the article are identified as a function of the slope. And an apparatus for identifying the first end and the second end of the article, characterized in that each other. 34. The method of claim 23, wherein The control and processing unit is programmed to identify a straight line passing through the two end points of the curve and to reproduce the coordinates of the point in a reference system, the coordinates being parallel to the straight line. And identify the first end and the second end of each other. The method of claim 23, wherein at least one of the preceding claims The control and processing unit is programmed to determine a difference between the maximum and minimum values of the coordinates of the curve in the reference system and to identify the first end from the second end based on the difference. A device for identifying the end and the second end from each other. 36. The method of claim 35 wherein Wherein said control and processing unit is programmed to compare said difference with a predetermined value and identify an end as said difference is greater or less than said predetermined value. Devices that identify each other. The method of claim 36 or 36, The control and processing unit, Determining coordinates of two points of the curve away from each other in a first reference system; Identifying a straight line to which the two points join; Taking this straight coupling line as one of the coordinates of the second reference system rotated with respect to the first reference system; And the first end and the second end of the article being programmed to perform the step of determining the difference in the second reference system. The method of claim 37, The first and second reference systems are Cartesian reference systems, and the difference is reproduced by the difference between the maximum and minimum values of the coordinates of the point of the curve along the axis of the reference orthogonal to the straight coupling line. Apparatus for identifying the first and second ends from each other. The method of claim 33 or 34, Wherein said control and processing unit is programmed to calculate a derivative of said curve. Wherein said control and processing unit is programmed with respect to said first end and said second end of said article, wherein said first and second ends of said derivative are programmed with respect to said minimum and maximum values. The method of claim 40, Wherein said control and processing unit is programmed to determine a difference between the maximum and minimum values of the derivative and to check the difference with a threshold. 42. The composition of claim 23, wherein at least one of: After the article has made a relative degree of relative movement starting from the blocking position of the first photovoltaic cell with respect to the photovoltaic cell, between the first and second ends based on the total number of photovoltaic cells blocked by the article. Wherein said control and processing unit is programmed to perform a first identification. The method of claim 23, wherein at least one of the preceding claims Wherein the sensor is disposed in a fixed position and the handling member causes translation of the article along a direction of movement towards the sensor. The method of claim 23, wherein at least one of the preceding claims And a handling member for moving the article relative to the sensor such that both ends of the article pass through the front of the sensor.

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