Web guide device, web width measurement method, and web width measurement program

Abstract

To provide a web guide device capable of measuring the width of a web with high accuracy using an analog edge sensor.SOLUTION: A web guide device 1 including a pair of edge sensors 3 for detecting the positions of both end parts of a web in a width direction includes: non-linear data acquiring means 41a for acquiring non-linear data that changes non-linearly with respect to a detection area of the edge sensor 3 based on a digital signal obtained by converting an analog signal output from the edge sensor 3 into the digital signal; converting means 41b for converting the non-linear data into linear data; and web width calculating means 41c for calculating the width of the web based on the linear data.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a web guide device equipped with a pair of edge sensors that detect the positions of both widthwise ends of a web, a web width measurement method implemented in the web guide device, and a web width measurement program executed in the web guide device. [Background technology]

[0002] In manufacturing lines or processing lines for strip-shaped materials (hereinafter referred to as "webs") such as paper, nonwoven fabric, film, and steel plate, the web may meander when wound around rollers and transported downstream due to imbalance of the rollers. Web meandering can lead to reduced productivity and the generation of defective products. For this reason, it is necessary to correct the meandering of the web. A web guide device is known as a device capable of correcting the meandering of the web (see, for example, Patent Document 1).

[0003] The web guiding device disclosed in Patent Document 1 is provided with a pair of analog edge sensors (position detection devices) that detect the positions of both widthwise ends of the web. The edge sensors include a light-emitting unit and a light-receiving unit, and the light-emitting unit and the light-receiving unit are arranged to sandwich the web in the thickness direction of the web so that the light-receiving unit can detect the amount of light by receiving light irradiated from the light-emitting unit. The light-receiving unit is electrically connected to a control unit and is configured to send a detection signal containing information about the detected amount of light to the control unit.

[0004] The amount of light detected by the light receiving unit changes depending on the relative position between the edge of the web and the edge sensor. Therefore, the control unit can determine the relative positions of both ends of the web and the pair of edge sensors based on the detection signal from the light receiving unit, and can determine whether the pair of edge sensors and the web have a predetermined positional relationship, more specifically, whether the midline of the pair of edge sensors is aligned with the central axis of the web. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-202889 Summary of the Invention [Problem to be solved by the invention]

[0006] In recent years, in web guide devices, as described above, in addition to determining whether the midline of a pair of edge sensors is aligned with the central axis of the web, there is a demand for the device to be able to measure the width of the web.

[0007] Incidentally, the pair of edge sensors used in the web guiding device of Patent Document 1 output analog signals, and the output analog signals exhibit nonlinear characteristics in the detection area. That is, the detection area of ​​the edge sensor is the area where the light receiving unit can receive and detect light irradiated from the light source. As the detection area expands from a state in which this detection area is blocked by the web to a state in which the area that is open due to a change in the position of the edge of the web relative to the detection area, the analog signal output from the light receiving unit changes nonlinearly, i.e., the output value itself increases but the amount of change in the output value gradually decreases. For this reason, measuring web width using a pair of edge sensors has low reliability and accuracy problems.

[0008] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a web guide device, a web width measurement method, and a web width measurement program that can measure the width of a web with high precision using an analog edge sensor. [Means for solving the problem]

[0009] The web guiding device according to the present invention for solving the above problems has the following characteristic configuration: A web guide device including a pair of edge sensors for detecting the positions of both widthwise ends of a web, a nonlinear data acquiring means for acquiring nonlinear data that varies nonlinearly with respect to the detection area of ​​the edge sensor based on a digital signal obtained by converting an analog signal output from the edge sensor into a digital signal; a conversion means for converting the nonlinear data into linear data; a web width calculation means for calculating the width of the web based on the linear data; The purpose is to provide the following.

[0010] In the web guiding device of this configuration, nonlinear data that varies nonlinearly with respect to the detection area of ​​the edge sensor is acquired by the nonlinear data acquiring means based on a digital signal obtained by converting an analog signal output from the edge sensor, and the acquired nonlinear data is converted by the converting means into linear data that varies linearly with respect to the detection area of ​​the edge sensor. The web width is then calculated by the web width calculating means based on this linear data, so that the web width can be measured with high accuracy using a relatively inexpensive analog edge sensor.

[0011] In the web guiding device according to the present invention, It is preferable that the conversion means divides the detection area of ​​the edge sensor into a plurality of sections, linearly approximates the nonlinear data in each section to set an approximated straight line, and sets an ideal straight line in which the output changes linearly in the detection area of ​​the edge sensor, and converts the approximated straight line into the ideal straight line in each of the sections.

[0012] According to the web guiding device of this configuration, an approximate line is set by linearly approximating nonlinear data in each of the multiple sections in the detection area of ​​the edge sensor, and an ideal line is set in which the output of the edge sensor changes linearly in the detection area. Then, a process is performed to convert the approximate line into an ideal line in each of the multiple sections in the detection area of ​​the edge sensor. This makes it possible to obtain ideal linear data that reflects the characteristics of the analog signal output from the edge sensor.

[0013] In the web guiding device according to the present invention, a meandering correction mechanism that corrects meandering of the web by swinging a roller around which the web is wound in the width direction of the web; a meandering correction controller for controlling the meandering correction mechanism; Furthermore, The meandering correction controller preferably includes the non-linear data acquisition means, the conversion means, and the web width calculation means.

[0014] According to the web guide device of this configuration, the meandering correction controller that controls the meandering correction mechanism includes a non-linear data acquisition means, a conversion means, and a web width calculation means, so there is no need to prepare a controller separate from the meandering correction controller to realize the functions of the non-linear data acquisition means, the conversion means, and the web width calculation means, thereby simplifying the device configuration and reducing costs.

[0015] In the web guiding device according to the present invention, It is preferable that the apparatus further comprises a movement mechanism for relatively moving the edge sensor in the width direction of the web.

[0016] With the web guiding device of this configuration, for example, when handling multiple types of webs with different widths on a production line or a required processing line, the pair of edge sensors are moved relative to each other in the width direction of the web so that both widthwise ends of the web are positioned within the detection ranges of the pair of edge sensors, thereby making it possible to measure the widths of multiple types of webs with different widths.

[0017] In the web guiding device according to the present invention, It is preferable that the edge sensor comprises a light-emitting unit or an ultrasonic wave-emitting unit arranged on one side of the thickness of the web, and a light-receiving unit or an ultrasonic wave-receiving unit arranged on the other side of the thickness of the web, and detects the position of the widthwise end of the web based on the amount of light received by the light-receiving unit or the volume of sound received by the ultrasonic wave-receiving unit.

[0018] The amount of light or sound volume detected by the light receiving unit or ultrasonic wave receiving unit changes depending on the change in the relative position of the edge of the web located between the light emitting unit or ultrasonic wave transmitting unit and the light receiving unit or ultrasonic wave receiving unit. With this configuration of the web guiding device, the position of the width direction edge of the web is detected based on the amount of light received by the light receiving unit or the sound volume received by the ultrasonic wave receiving unit, so the width of the web can be accurately measured based on the deviation (deviation) of the edge of the web from the reference position of the edge sensor.

[0019] The web width measurement method according to the present invention for solving the above problems is characterized by the following configuration: a nonlinear data acquisition step of acquiring nonlinear data that varies nonlinearly with respect to the detection areas of a pair of edge sensors based on digital signals obtained by converting analog signals output from the edge sensors, which detect the positions of both ends of the web in the width direction; a conversion step of converting the non-linear data into linear data; a web width calculation step of calculating a width of the web based on the linear data; The purpose is to encompass the above.

[0020] According to the web width measurement method of this configuration, nonlinear data that varies nonlinearly with respect to the detection area of ​​the edge sensor is acquired based on a digital signal obtained by converting an analog signal output from the edge sensor into a digital signal (nonlinear data acquisition step), and the acquired nonlinear data is converted into linear data that varies linearly with respect to the detection area of ​​the edge sensor (conversion step).Then, the web width is calculated based on this linear data (web width calculation step), so that the web width can be measured with high accuracy using a relatively inexpensive analog edge sensor.

[0021] The web width measurement program according to the present invention for solving the above problems is characterized by the following configuration: The object is to make a computer execute the above-described web width measuring method.

[0022] According to the web width measurement program of this configuration, when installed on a computer, it becomes possible to measure the width of a web with high accuracy even when using an existing web guide device that uses a relatively inexpensive analog edge sensor. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 is a partially cutaway plan view of a web guiding device according to an embodiment of the present invention. [Figure 2] FIG. 2 is an explanatory diagram of the edge sensor and its output characteristics. [Figure 3] FIG. 3 is a functional block diagram of the meandering correction controller. [Figure 4] FIG. 4 is an explanatory diagram of a method for converting nonlinear data into linear data. [Figure 5] FIG. 5 is an explanatory diagram relating to the deviation amount of the web in the linearization target region. [Figure 6] FIG. 6 is an explanatory diagram of a method for calculating the web width. [Figure 7] FIG. 7 is a flowchart showing the procedure of the process executed in the linearization calibration unit. DETAILED DESCRIPTION OF THE INVENTION

[0024] The present invention will be described below with reference to the drawings. However, the present invention is not intended to be limited to the embodiments described below or the configurations shown in the drawings.

[0025] <Overall structure> 1 is a partially cutaway plan view of a web guiding device 1 according to one embodiment of the present invention. As shown in Fig. 1, the web guiding device 1 of this embodiment includes a meandering correction mechanism 2 that corrects meandering of the web W, a movement mechanism 4 that moves a pair of edge sensors 3 relatively in the width direction of the web W, and a meandering correction controller 5 that controls the meandering correction mechanism 2 and the like.

[0026] <Meandering correction mechanism> The meandering correction mechanism 2 includes a base 10, a movable frame 11, rollers 12, and a swing mechanism 13. The base 10 is fixed to a frame or the like in a manufacturing line or processing line (not shown). The movable frame 11 is disposed opposite the base 10. A pair of rollers 12 (only one of which is shown) are rotatably attached to the movable frame 11 and are arranged parallel to each other at a predetermined distance in the conveyance direction of the web W. The web W is wrapped around the pair of rollers 12. The swing mechanism 13 is configured to move the movable frame 11 freely around a fulcrum 14 on a plane parallel to the base 10 and facing the base 10, using a fulcrum 14 and a support mechanism (not shown). The swing mechanism 13 includes an actuator (not shown) driven electrically or hydraulically, and is configured to swing the pair of rollers 12 in the width direction of the web W along a plane including the central axes of both rollers 12 via the movable frame 11 by swinging the fulcrum 14 in response to a control signal from the meandering correction controller 5. The fulcrum 14 may be a mechanical fulcrum or a virtual fulcrum.

[0027] <Movement mechanism> The movement mechanism 4 includes a pair of holding members 20 that hold the pair of edge sensors 3, and a pair of screw mechanisms 21 disposed on the base 10 to correspond to the pair of edge sensors 3. Here, the screw mechanism 21 includes a screw 22 having a screw shaft portion and a nut portion, and a motor 23 that is connected to the screw shaft portion of the screw 22 so as to be able to transmit rotational power. In the movement mechanism 4, one end of the holding member 20 is fixed to a frame 30 (described later) of the edge sensor 3, and the other end of the holding member 20 is fixed to the nut portion of the screw 22. The rotational power from the motor 23 is converted into linear power by the screw 22, and this linear power can be transmitted to the pair of edge sensors 3 via the pair of holding members 20. The edge sensor 3 can be moved relatively in the width direction of the web W by rotating the motor 23 forward or backward according to a control signal from the meandering correction controller 5.

[0028] <Edge sensor> FIG. 2 is an explanatory diagram of the edge sensor 3 and its output characteristics. FIG. 2(a) is a diagram showing the relative positional relationship between the edge sensor 3 and the end of the web W. As shown in FIG. 2(a), the pair of edge sensors 3 detect the positions of both widthwise ends of the web W and include a frame 30, a light-emitting unit 31, and a light-receiving unit 32. The frame 30 is formed in a groove shape that is open on the side where the web W is placed, and has a pair of arms 30a, 30b that are arranged opposite each other and sandwich the end of the web W therebetween. The light-emitting unit 31 is embedded in one arm 30a of the pair of arms 30a, 30b so that it can irradiate light onto the end of the web W. The light-receiving unit 32 is embedded in the other arm 30b so that it can receive light irradiated from the light-emitting unit 31. The light-emitting unit 31 comprises, for example, a light-emitting diode that emits infrared light or the like, and the light-receiving unit 32 comprises, for example, a photodiode, and functions as an optical sensor when the light-emitting unit 31 and the light-receiving unit 32 are used in pair so that the light-receiving unit 32 receives light having a circular cross section irradiated from the light-emitting unit 31, and an analog signal (voltage or current) corresponding to a change in the amount of received light that accompanies a change in the relative position of the end of the web W located between the light-emitting unit 31 and the light-receiving unit 32 is output from the light-receiving unit 32. The light-receiving unit 32 is electrically connected to the meandering correction controller 5, and transmits a detection signal including information about the detected amount of light to the meandering correction controller 5.

[0029] FIG. 2(b) is a graph showing the relationship between the detection area R of the edge sensor 3 and the analog signal output. As shown in FIG. 2(b), the analog signal output from the light-receiving unit 32 exhibits nonlinear characteristics in the detection area R. That is, the area where the light-receiving unit 32 can receive and detect light irradiated from the light-emitting unit 31 is the detection area R of the edge sensor 3. As the detection area R expands from a state in which the web W shields the detection area R to a state in which the edge of the web W is positioned relative to the detection area R, the analog signal output from the light-receiving unit 32 increases in output value, but the amount of change in the output value gradually decreases, resulting in a nonlinear change. That is, as the distance (X: see FIG. 2(a)) from the position where the detection area R is shielded by the web W to the edge surface of the web W increases (moving toward the open side (right side) on the horizontal axis of the graph in FIG. 2(b)), the analog signal output from the light-receiving unit 32 gradually decreases in output value, resulting in a nonlinear change. Therefore, when measuring the width of the web W, it is necessary to perform a linearization calibration process, which will be described later.

[0030] The amount of light detected by the light receiving unit 32 changes depending on the change in the relative position between the end of the web W and the edge sensor 3. Therefore, based on the detection signal from the light receiving unit 32, the meandering correction controller 5 can grasp the relative positions of both end portions of the web W and the pair of edge sensors 3, and can grasp whether the pair of edge sensors 3 and the web W have a predetermined positional relationship, more specifically, whether the middle line of the pair of edge sensors 3 and the central axis of the web W are aligned, and can measure the deviation (deviation) of the end of the web W from the reference position of the edge sensor 3.

[0031] In addition, in the pair of edge sensors 3, an ultrasonic transmitter may be used instead of the light emitting unit 31, and an ultrasonic receiver may be used instead of the light receiving unit 32, and based on the volume received by the ultrasonic receiver, it may be determined whether the midline of the pair of edge sensors 3 coincides with the central axis of the web W, and the deviation (deviation) of the end of the web W relative to the reference position of the edge sensor 3 may be measured.

[0032] <Meandering correction controller> Fig. 3 is a functional block diagram of the meandering correction controller 5. The meandering correction controller 5 shown in Fig. 3 is mainly composed of a computer, and includes an A / D conversion unit 40 that converts analog signals from the edge sensor 3 into digital signals, a linearization calibration unit 41 that performs linearization calibration processing and the like, a meandering correction mechanism control unit 42 that controls the meandering correction mechanism 2, and a movement mechanism control unit 43 that controls the movement mechanism 4. In the meandering correction controller 5, a predetermined program is executed by an MPU (Micro Processor Unit), thereby causing the respective functions of the A / D conversion unit 40, the linearization calibration unit 41, the meandering correction mechanism control unit 42, and the movement mechanism control unit 43 to be fulfilled.

[0033] The linearization calibration unit 41 includes a nonlinear data acquisition means 41a, a conversion means 41b, and a web width calculation means 41c.

[0034] <Nonlinear data acquisition method> FIG. 4 is an explanatory diagram of a technique for converting nonlinear data into linear data. FIG. 4(a) is an explanatory diagram of a linearization target area Ra set within the detection area R of the edge sensor 3. FIG. 4(b) is a graph showing the relationship between the linearization target area Ra of the edge sensor 3 and the approximate lines BL1-BL4 and ideal line CL set for the linearization target area Ra. As shown in FIG. 4(a), a linearization target area Ra is set within the detection area R of the edge sensor 3, the linearization target area Ra being, for example, 5 to 10% narrower than the detection area R. That is, the linearization target area Ra is set as a target area for linearization processing, which is a portion of the detection area R of the edge sensor 3 where the amount of change in the analog signal due to a relative positional change of the edge of the web W is above a predetermined threshold and below a predetermined threshold. That is, the linearization target area Ra is set so as to exclude portions of the detection area R of the edge sensor 3 where the amount of change in the analog signal output from the light receiving unit 32 becomes extremely small. Then, in Figure 4(b), as shown by the dashed line marked with the symbol AL in the figure, the nonlinear data acquisition means 41a (see Figure 3) acquires nonlinear data that changes nonlinearly in the linearization target region Ra based on the digital signal from the A / D conversion unit 40.

[0035] <Conversion method> As shown in FIG. 4(b), the conversion means 41b (see FIG. 3) divides the linearization target area Ra inside the detection area R of the edge sensor 3 into a plurality of sections K1 to K4 (four in this example), and sets approximated straight lines BL1 to BL4 by linearly approximating the nonlinear data (line AL: see FIG. 4(b)) in each of the sections K1 to K4. The conversion means 41b also sets an ideal straight line CL in which the output changes linearly in the linearization target area Ra. The conversion means 41b then performs a process of converting the approximated straight lines BL1 to BL4 into the ideal straight lines CL (CL1 to CL4). Examples of the conversion process include deriving a conversion equation for converting the approximated straight lines BL1 to BL4 into the ideal straight lines CL1 to CL4 in each of the plurality of sections, and converting the approximated straight lines BL1 to BL4 into the ideal straight lines CL1 to CL4 using the derived conversion equation. There are various possible specific methods for deriving the conversion formulas, but for example, a conversion formula can be obtained geometrically based on coordinate point data of both ends of the approximated straight lines BL1-BL4 in each of the sections K1-K4 (in this example, the coordinate point data of [point M1, point M2], [point M2, point M3], [point M3, point M4], and [point M4, point M5] in the graph of FIG. 4(b)) and coordinate point data on the ideal straight lines CL1-CL4 corresponding to the approximated straight lines BL1-BL4 in each of the sections K1-K4 (in this example, the coordinate point data of [point N1, point N2], [point N2, point N3], [point N3, point N4], and [point N4, point N5] in the graph of FIG. 4(b)). Alternatively, in each of the sections K1-K4, the approximated straight lines BL1-BL4 and the ideal straight lines CL1-CL4 can be expressed as functional formulas, and the conversion formula can be obtained from the relationship between the two functional formulas.

[0036] In this way, nonlinear data, such as that shown by the dashed line marked with the symbol AL in FIG. 4(b), in which the output value of the digital signal and the linearization target area Ra have a nonlinear relationship, is converted into linear data (ideal straight line CL) in which the output value of the digital signal and the linearization target area Ra have a linear relationship. According to the linear data (ideal straight line CL) shown in FIG. 4(b), when the open rate is 0%, the linearization target area Ra is completely blocked by the web W, and the output is minimum (voltage: 0 V). When the open rate is 100%, the linearization target area Ra is completely open without being blocked by the web W, and the output is maximum (voltage: set voltage upper limit value Vmax). When the open rate increases / decreases between 0% and 100%, the digital signal output (Vx_cal) converted by the conversion means 41b, output from the light receiving unit 32, changes linearly with the increase / decrease in the open rate X_%.

[0037] 5 is an explanatory diagram of the deviation amount X_err of the web W in the linearization target area Ra. FIG. 5(a) is an explanatory diagram of the definition of the deviation amount X_err of the web W in the linearization target area Ra of the edge sensor 3. In FIG. 5(a), the deviation amount X_err indicates the magnitude of the deviation of the end of the web W from the reference position (center position) of the edge sensor 3. Here, the deviation amount X_err collectively refers to the deviation amount Xl_err and the deviation amount Xr_err, which will be described later.

[0038] FIG. 5B is a graph showing the relationship between the linearization target area Ra of the edge sensor 3 and the deviation amount X_err. For example, as shown in FIG. 5B, if the length of the linearization target area Ra in the width direction of the web W is set to 10.0 mm, the position specified by the length to the end face of the web W in the linearization target area Ra and the open area ratio of the linearization target area Ra are associated as follows: That is, the position where the length to the end face of the web W in the linearization target area Ra is 0.0 mm corresponds to the open area ratio of 0% in the linearization target area Ra (see FIG. 4B). Similarly, the position where the length to the end face of the web W in the linearization target area Ra is 5.0 mm corresponds to the open area ratio of 50% in the linearization target area Ra (see FIG. 4B). Similarly, the position where the length to the end face of the web W in the linearization target area Ra is 10.0 mm corresponds to the open area ratio of 100% in the linearization target area Ra (see FIG. 4B). Here, in FIG. 5(b), any position within the linearization target region Ra, which is between 0.0 mm and 10.0 mm in length to the end face of the web W, is represented as X_mm.

[0039] 4(b) and 5(b) will be compared for explanation. In FIG. 4(b), when the digital signal output (Vx_cal) output from the light receiving unit 32 after conversion processing by the conversion means 41b is 0, the open rate of the linearization target region Ra is 0%. An open rate of 0% indicates that the linearization target region Ra is completely blocked and shielded by the web W. Therefore, in FIG. 5(b), the deviation amount X_err at a position where the length to the end face of the web W in the linearization target region Ra is 0.0 mm is +5.0 mm. In FIG. 4(b), when Vx_cal is Vmax, the open rate of the linearization target region is 100%. An open rate of 100% indicates that the linearization target region Ra is completely open and not blocked by the web W. Therefore, in FIG. 5(b), the deviation amount X_err at a position where the length to the end face of the web W in the linearization target region Ra is 10.0 mm is -5.0 mm. In FIG. 4(b), when Vx_cal is the intermediate value (Vmid) between 0 and Vmax, the open rate of the linearization target area Ra is 50%. An open rate of 50% indicates that half of the linearization target area Ra is blocked by the web W, and the other half is open. Therefore, in FIG. 5(b), the deviation amount X_err at the position 5.0 mm from the edge of the web W in the linearization target area Ra is 0.0 mm, since the edge of the web W is located at the reference position (center position) of the edge sensor 3. In FIG. 4(b), when Vx_cal increases / decreases between 0 and Vmax, the open rate X_% of the linearization target area Ra increases / decreases depending on the degree of the slope of the ideal line CL. In FIG. 5(b), the deviation amount X_err at the position X_mm from the edge of the web W in the linearization target area Ra decreases / increases between +5.0 mm and -5.0 mm. That is, as shown in Fig. 5(b), the length X_mm to the end face of the web W in the linearization target region Ra and the deviation amount X_err have a linearly changing relationship as shown by the line DL. Here, when a virtual vertical axis F is set that is perpendicular to the horizontal axis at a length of 5.0 mm in the linearization target region Ra, the line DL is a line projected so as to be symmetrical to the ideal line CL in the graph of Fig. 4(b) with the virtual vertical axis F as the base.

[0040] <Web width calculation method> FIG. 6 is an explanatory diagram of a method for calculating the web width. FIG. 6(a) is a diagram showing the relative positional relationship of the web W with respect to the pair of edge sensors 3. FIG. 6(b) is a view seen from the arrow GG in FIG. 6(a). The web width calculation means 41c calculates the width WW of the web W from various data including the deviation amount X_err (Xl_err, Xr_err) obtained based on the linear data (ideal straight line CL) converted by the conversion means 41b. That is, when "Set", "Xl_err", and "Xr_err" are defined as follows, the web width calculation means 41c calculates the width WW of the web W using the following equation (1): Web width WW = Set + Xl_err + Xr_err (1) “Set”: The distance between the reference positions of a pair of edge sensors 3 (the distance between the detection centers). "Xl_err": the deviation amount detected by one edge sensor 3 (the left side in FIG. 6) of the pair of edge sensors 3 (X_err: see FIG. 5(a)). "Xr_err": the deviation amount detected by the other edge sensor 3 (the right side in FIG. 6) of the pair of edge sensors 3 (X_err: see FIG. 5(a)). The above "Set" is a known value that can be measured by the meandering correction controller 5 based on, for example, a signal from an encoder attached to the motor 23 in the moving mechanism 4 or a signal such as the number of pulses converted into the distance from the mechanical origin of the moving mechanism 4.

[0041] 7 is a flowchart showing the procedure of the linearization calibration process and the like executed in the linearization calibration unit 41. Note that the symbol "S" in FIG. 7 represents a step.

[0042] <S1~S2> [Linearization target area setting process, nonlinear data acquisition process] In the meandering correction controller 5, first, as shown in Fig. 4(a), the nonlinear data acquisition means 41a in the linearization calibration unit 41 sets a linearization target area Ra inside the detection area R of the edge sensor 3 (S1: linearization target area setting step). Next, the nonlinear data acquisition means 41a acquires nonlinear data (line AL: see Fig. 4(b)) that changes nonlinearly in the linearization target area Ra based on the digital signal from the A / D conversion unit 40 (S2: nonlinear data acquisition step).

[0043] <S3~S5> [Dividing process, straight line setting process, conversion process] As shown in Fig. 4(b), the conversion means 41b in the linearization calibration unit 41 divides the linearization target region Ra into a plurality of sections K1 to K4 (S3: division step). Next, the conversion means 41b linearly approximates the nonlinear data (line AL) in each of the sections K1 to K4 to set approximated lines BL1 to BL4, and also sets an ideal line CL (CL1 to CL4) along which the output changes linearly in the linearization target region Ra (S4: approximation / ideal line setting step). Then, the conversion means 41b performs a process of converting the approximated lines BL1 to BL4 into the ideal lines CL1 to CL4 (S5: conversion step).

[0044] In this way, approximate straight lines BL1-BL4 are set by linearly approximating the nonlinear data (line AL: see FIG. 4(b)) in each of the multiple sections K1-K4 in the linearization target area Ra set inside the detection area R of the edge sensor 3, and an ideal straight line CL along which the output changes linearly is set in the linearization target area Ra of the edge sensor 3. Then, a process is performed to convert the approximate straight lines BL1-BL4 into the ideal straight line CL (CL1-CL4) in each of the multiple sections K1-K4 in the linearization target area Ra of the edge sensor 3. This makes it possible to obtain ideal linear data that reflects the characteristics of the analog signal output from the edge sensor 3.

[0045] <s6> Then, the web width calculation means 41c in the linearization calibration unit 41 calculates the width WW of the web W using the above formula (1) from various data including the deviation amount X_err obtained based on the linear data (ideal straight line CL) converted by the conversion means 41b. In this way, the width WW of the web W can be measured with high accuracy using a relatively inexpensive analog edge sensor 3.

[0046] In the web guiding device 1 of this embodiment, the meandering correction controller 5 can grasp the relative positions of both ends of the web W and the pair of edge sensors 3 based on the detection signal from the light receiving unit 32. Therefore, when it is determined that the web W is meandering based on the relative positional relationship between both ends of the web W and the pair of edge sensors 3, a control signal is sent to the swinging mechanism 13 to swing the pair of rollers 12 via the movable frame 11 in the width direction of the web W along a plane including both central axes of the pair of rollers 12, thereby correcting the meandering of the web W.

[0047] For example, when handling multiple types of webs W with different widths on a production line or a required processing line, it is necessary to adjust the relative positions of the pair of edge sensors 3 with respect to the web W to be appropriate according to the width of the web W. In such a case, the meandering correction controller 5 sends a control signal to the movement mechanism 4 to move the pair of edge sensors 3 relatively in the width direction of the web W, thereby positioning both widthwise ends of the web W so that they can be detected within the detection regions R (linearization target regions Ra) of the pair of edge sensors 3. In this way, the widths WW of multiple types of webs W with different widths can be measured.

[0048] In the web guide device 1 of this embodiment, the meandering correction controller 5 that controls the meandering correction mechanism 2 includes a nonlinear data acquisition means 41a, a conversion means 41b, and a web width calculation means 41c, so there is no need to prepare a controller separate from the meandering correction controller 5 to realize the functions of the nonlinear data acquisition means 41a, the conversion means 41b, and the web width calculation means 41c, thereby simplifying the device configuration and reducing costs.

[0049] The above describes the web guide device, web width measurement method, and web width measurement program of the present invention based on one embodiment, but the present invention is not limited to the configuration described in the above embodiment, and the configuration can be changed as appropriate within the scope of the spirit thereof. [Industrial Applicability]

[0050] The web guide device, web width measurement method, and web width measurement program of the present invention can be particularly effectively used in applications such as measuring the width of a web in manufacturing lines or required processing lines for strip-shaped materials (webs) such as paper, nonwoven fabric, film, steel plate, etc. [Explanation of symbols]

[0051] 1. Web guide device 2 Meandering correction mechanism 3 Edge Sensor 4 Moving mechanism 5. Snake Correction Controller 12 Laura 31 Light-emitting part 32 Light receiving part 41a Nonlinear data acquisition methods 41b Conversion Method 41c Web width calculation method W Web

Claims

1. A web guide device including a pair of edge sensors for detecting the positions of both widthwise ends of a web, a nonlinear data acquiring means for acquiring nonlinear data that varies nonlinearly with respect to the detection area of ​​the edge sensor based on a digital signal obtained by converting an analog signal output from the edge sensor into a digital signal; a conversion means for converting the nonlinear data into linear data; a web width calculation means for calculating a width of the web from a deviation of an end of the web from a reference position of the edge sensor obtained based on the linear data; A web guiding device comprising:

2. A web guide device having a pair of edge sensors that detect the positions of both widthwise ends of a web, a nonlinear data acquiring means for acquiring nonlinear data that varies nonlinearly with respect to the detection area of ​​the edge sensor based on a digital signal obtained by converting an analog signal output from the edge sensor into a digital signal; a conversion means for converting the nonlinear data into linear data; a web width calculation means for calculating the width of the web based on the linear data; Equipped with The conversion means divides the detection area of ​​the edge sensor into multiple sections, linearly approximates the nonlinear data in each section to set an approximate straight line, and sets an ideal straight line in which the output changes linearly in the detection area of ​​the edge sensor, and converts the approximate straight line into the ideal straight line in each of the sections.

3. a meandering correction mechanism that corrects meandering of the web by swinging a roller around which the web is wound in the width direction of the web; a meandering correction controller for controlling the meandering correction mechanism; Furthermore, The web guiding device according to claim 1 or 2, wherein the meandering correction controller includes the nonlinear data acquiring means, the converting means, and the web width calculating means.

4. The web guiding device according to claim 1 or 2, further comprising a movement mechanism that moves the edge sensor relatively in the width direction of the web.

5. The edge sensor comprises a light-emitting unit or an ultrasonic wave-emitting unit arranged on one side of the thickness direction of the web, and a light-receiving unit or an ultrasonic wave-receiving unit arranged on the other side of the thickness direction of the web, and detects the position of the widthwise end of the web based on the amount of light received by the light-receiving unit or the volume of sound received by the ultrasonic wave-receiving unit.

6. a nonlinear data acquisition step of acquiring nonlinear data that varies nonlinearly with respect to the detection areas of a pair of edge sensors based on digital signals obtained by converting analog signals output from the edge sensors, which detect the positions of both ends of the web in the width direction; a conversion step of converting the non-linear data into linear data; a web width calculation step of calculating a width of the web from a magnitude of deviation of the edge of the web from a reference position of the edge sensor obtained based on the linear data; A web width measurement method comprising:

7. A nonlinear data acquisition process for acquiring nonlinear data that changes nonlinearly with respect to the detection area of ​​a pair of edge sensors based on digital signals obtained by converting analog signals output from the edge sensors that detect the positions of both ends of the web in the width direction; a conversion step of converting the non-linear data into linear data; a web width calculation step of calculating a width of the web based on the linear data; It encompasses In the conversion step, the detection area of ​​the edge sensor is divided into a plurality of sections, the non-linear data is linearly approximated in each section to set an approximated line, and an ideal line in which the output changes linearly in the detection area of ​​the edge sensor is set, and the approximated line in each section is converted to the ideal line.

8. A web width measuring program for causing a computer to execute the web width measuring method according to claim 6 or 7.

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