JPS61195303A - Instrument for measuring characteristic of sheet-like object - Google Patents

Abstract

PURPOSE:To enable accurate measurement of a sheet-like object by providing two sensor heads reciprocated in a direction perpendicular to the running direc tion, a speed sensor and arithmetic operation control means. CONSTITUTION:The sensor heads 2, 3 are reciprocated within frames 20, 30 in a direction approximately perpendicular to the running direction of the sheet- like object 1 with the speed sensor 4 sensing the running speed of the object 1. Assuming that the head 2 is scanning at a constant speed, should the speed of the object be changed, the time point when the scanning start point of the head 2 arrives at the head 3 downstream by a distance L and the speed of the object 1 sensed by the sensor 4 are stored and computed in a memory- operating device 5 for controlling driving devices 21, 31 driving the heads 2, 3. Hence, the head 3 faithfully follows the locus of the detected points of the head 2 for accurately measuring the properties of the sheet-like object 1.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a sheet-like object characteristic measuring device for measuring the characteristics (for example, thickness, moisture, etc.) of a traveling sheet-like object.
More specifically, the present invention relates to a sheet-like object characteristic measuring device that measures characteristics by calculating detection signals obtained while reciprocating two detection heads in the width direction of the sheet-like object.

(Prior Art) FIG. 6 is a conceptual diagram of the configuration of a conventional device of this type. In the figure, 1 is a sheet-like object such as papermaking running in the direction of arrow a, and 2 and 3 are directions I (hereinafter referred to as the width direction) substantially orthogonal to the running direction of the sheet-like object 1.
C is a detection head that moves back and forth and detects the characteristics of a sheet-like object, and is movably supported by the 0-type frames 20 and 30, respectively.

Further, the 0 frames 20 and 30 are installed apart from each other by a distance in the traveling direction of the sheet-like object 1.

The broken line 10 shown on the sheet-like object 1 is the locus of the detection point by the upstream detection head 2, and the downstream detection head 3 is on the locus of this detection point (therefore, at the same detection position)
The detection head 1 moves back and forth in the width direction of the sheet-like object in synchronization with the detection head 2 along the width direction of the sheet-like object.

(Problems to be Solved by the Invention) In the conventional device having such a configuration, the upstream rain detection heads 2 and 3 are synchronously moved back and forth at a constant speed. For this reason, if the traveling speed V of the sheet-like object 1 changes after the sheet-like object 1 starts traveling, the downstream detection head 3 will no longer accurately follow the trajectory of the detection point, and will move to a position different from the detection position of the upstream detection head 2. will be detected. For this purpose, the signal from the upstream detection head 2 and the signal from the downstream detection head 3 are mutually calculated to calculate, for example, coating I (in this case, coating is performed by one detection head). Detect the basis weight before coating, detect the basis weight after coating with the other detection head, and calculate the coating amount from the difference),
There is a problem that it becomes impossible to obtain an accurate coating amount signal.

The present invention has been made in view of such problems in the prior art, and its purpose is to enable the downstream detection head to maintain the detection point of the upstream detection head even if the traveling speed of the sheet-like object changes midway. The present invention aims to realize a sheet-like object characteristic measuring device that can accurately follow a trajectory and accurately measure the characteristics of a sheet-like object.

(Means for solving the intercultivation point) The device of the present invention for solving the above-mentioned problem has a detection head @1 that reciprocates in a direction substantially perpendicular to the traveling direction of the sheet-like object, and a second detection head located a predetermined distance downstream from the first detection head running position in the running direction of the object and reciprocating in a direction substantially orthogonal to the running direction of the sheet-like object; a speed detector that detects the running speed of the sheet-like object; a control means that inputs a signal from the speed detector and controls the running start timing and running speed of the second detection head based on the signal; Said 1st. A calculation means inputs signals from the second detection heads 2 and 3 and performs a predetermined calculation to obtain a signal related to the characteristics of the sheet object.

(Example) FIG. 1 is a conceptual diagram showing an example of a device according to the present invention.

fJ! , 1, 21 is a drive device for reciprocating the upstream detection head 2 in the width direction, 31 is a drive device for reciprocating the downstream detection head 3 in the width direction, and 4 is a drive device for controlling the traveling speed V of the sheet-like object 10. The speed detector 5 inputs the signal V from the speed detector 4, each detection p', the signal from the heads 2 and 3, and inputs the signals from each drive unit [
A computer (CPU), for example, is used as an arithmetic and control device that outputs control signals to the terminals 21 and 31 and calculates the characteristics of the sheet-like object l.

FIG. 2 is a functional block diagram showing details of this arithmetic and control device 5. As shown in FIG. In this figure, 5a is a control means that inputs a signal from the speed detector 4 and controls the running start timing and running speed of the second detection head 30 based on this signal. The control means 5a includes a memory 51 storing data regarding the distance LK between the frames 20 and 30 supporting the detection head 2 and the detection head 3, respectively, and an integration function that integrates the speed signal Vp from the speed detector 4. Means 52
, data regarding the distance from the memory 51, and data Σvp from the integration means 52 are input, and the first detection head 2
A prediction calculation means 53 predicts and calculates the time when the scanning (reciprocating) start point of the apparatus arrives at the detection position of the second detection head 3, and instructs the timing of starting the movement of the second detection head 3. There is. Also, the speed signal Vp from the speed detector 4
a memory 54 that stores data sequentially for a certain period of time; a memory 55 that stores data regarding the running speed vIK of the first detection head 2;
A calculating means that inputs the speed signal Vp(tO) at the time of detection, the current speed signal v, (to+t), and the running speed v1 of the first detection head 20, and calculates the running speed v2 of the second detection head 3. 56.

5b is the first. A signal from the second detection head 2.3 is input, and a predetermined calculation is performed, for example, a thickness signal and a moisture content signal are input, and an absolute dry basis weight is calculated by excluding the moisture content from these. It is an arithmetic circuit.

The operation of the device configured in this way will be described next.

FIG. 3 is a diagram showing a detection position locus of the detection head 2 when the traveling speed of the first detection head 2 is constant and the traveling speed of the sheet-like object 1 changes. Here, t
o, tO+ 1. to + 2... indicates that at the time of detection by the first detection head 2, the angle of the locus with respect to the traveling direction is θl, θ2, . θ3... changes in accordance with the traveling speed of the sheet-like object 1.

The second detection head 3 is similar to such a first detection head 2.
In order to follow the trajectory of 1, its traveling speed v2 is controlled moment by moment by the arithmetic and control unit s according to the following equation.

FIG. 4 is a flowchart for obtaining a running start timing command for the second detection head 30.

First, the integrating means 52 receives the speed signal Vp from the speed detector 4 (step 1) and integrates this speed signal (step 2). Subsequently, the prediction calculation means 53 calculates the distance-related data L and the integrated data Xv from the integrating means 52.
Compare with P and determine whether XvP≧L (Step 3)
. In this step 3, steps 1 to 3 are repeated until XVP≧L, and when XVP≧L, the process moves to step 4, where the second detection head 20 starts running via the drive device 31. Outputs a command signal to
finish.

FIG. 5 is a flowchart for obtaining a speed control signal for the second detection head 3.

The memory means 54 receives the speed signal Vp from the speed detector 4 and sequentially stores it (step 1).

The calculation means 56 receives the speed signal Vp(t□) at time 16 from the memory means 54, and the speed signal Vp(to +
t) and the first detection head 20 traveling speed gator v1
is input, and the calculation Vp(t+to)vl·(,,,) is performed to obtain the running speed V2(t+tO) of the second detection head 30 (step 2). Subsequently, this traveling speed signal V2(t + t(1
) is output to the drive device of the second detection head 3 (step 3). Subsequently, it is determined whether or not the second detection head 3 has arrived at the turning point (step 4), and the process ends upon reaching the turning point.

Through the above-described operation, the widthwise running speed v2 of the second detection head 3 is controlled so that the detection position thereof coincides with the detection position by the first detection head.

Note that although the above description has been made regarding the case where there are two detection heads, the present invention can also be applied to a case where a larger number of detection heads are installed.

(Effects of the Invention) As explained above, according to the present invention, even if the traveling speed of the sheet-like object changes midway, the traveling speed of the downstream detection head is controlled, and the characteristics of the sheet-like object can be controlled. A sheet-like object characteristic measuring device that can accurately measure properties can be realized.

[Brief explanation of drawings]

Fig. 1 is a conceptual configuration diagram showing an example of the device according to the present invention, Fig. 2 is a functional block diagram showing details inside the arithmetic and control unit in Fig. 1, and Fig. 3 is a first detection head on a sheet object. 4 and 5 are flowcharts showing an example of the operation of the arithmetic and control device, and FIG. 6 is a conceptual diagram of the configuration of the conventional device. DESCRIPTION OF SYMBOLS 1... Sheet-like object, 2... First detection head, 3...
...Second detection head, 4. Speed detector, 5. Arithmetic control device, 5a.. Control means, 5b.. Arithmetic means. Figure 2 Figure 6

Claims (1)

[Claims] a first detection head that reciprocates in a direction substantially perpendicular to a direction in which the sheet-like object travels; a second detection head that reciprocates in a direction substantially orthogonal to the running direction of the sheet-like object; a speed detector that detects the running speed of the sheet-like object; a control means for controlling running start timing and running speed of the second detection head based on a signal; and the first and second detection heads 2;
2. A sheet-like object characteristic measuring device, comprising: arithmetic means for inputting a signal from 3 and performing a predetermined calculation to obtain a signal related to the characteristic of the sheet object.