JP3097516B2 - Response speed compensation device for scan type sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a travel control device for a scan type sensor used in a paper machine control system and the like.
In particular, the present invention relates to an improvement in which a fixed point observation can be performed by individually compensating for each of a plurality of sensors even if a fluctuation occurs in a reciprocating speed.

[0002]

2. Description of the Related Art In a paper machine, control is performed so that the quality of paper to be manufactured is equalized to a standard value. As disclosed in Japanese Patent Application Laid-Open No. 1-192892, the quality of paper is measured by reciprocally scanning a sensor for measuring basis weight, moisture content, paper thickness and the like in the paper width direction. At this time, the trajectory drawn on the paper on which the sensor is manufactured is zigzag, so that the measurement components are separated in the width direction and the flow direction of the paper. For example, in profile control of basis weight, an operating end called a slice bolt distributed in the paper width direction is opened and closed to manufacture paper having a uniform basis weight in the paper width direction. here,
Since the sensor reciprocates in the paper width direction, it is suitable for profile control if it can be controlled so that the measurement position in the forward movement and the measurement position in the backward movement coincide.

FIG. 4 is a diagram for explaining the relationship between the paper width direction and the measurement position. Here, zones 1, 2, 3,..., N defining measurement positions at regular intervals in the paper width direction (for example, N is 360
) Are provided, and N measurement positions are determined in the maximum measurement width. The center of each zone is assigned as the measurement start timing point of the sensor in each zone. There are forward FW and backward BW in the traveling direction of the sensors, and when the sensors pass the measurement start timing point, the measurement of each sensor is started.

FIG. 5 is a distribution diagram in the width direction of the measured values of the scanning speed and the forward / backward basis weight. Here, the time required for scanning in the paper width direction is used as an index of the scanning speed, and for (1) to (6), 14.6, 16.0, 19.2, 24.4, 35.0 and 72.8 [sec / one-way scan] are shown in order. ing. In the figure, “RBW indicator” indicates that the measured value of the grammage is displayed, and “◆ average” indicates the average value of the measured values of the grammage [g / c.
m ² ], the vertical bar “+” on the horizontal line near the center of each graph indicates the position of the slice bolt, the number on the horizontal axis indicates the number of the measurement point, and “F” indicates the end. It is.

It is ideal that each sensor performs the measurement at a point directly above each zone, but each sensor requires a certain amount of time for the measurement. Therefore, the measurement starting position corresponding to the time delay of the measurement system is shifted with respect to the typical scanning speed. Then, in the case of 24.4 seconds, which is close to the typical scanning speed, the measured value distributions of the forward FW and the backward BW substantially match each other.

[0006]

However, in the case of 72.8 seconds, which is extremely slow with respect to the typical scanning speed, or in the case of 14.6 to 16.0 seconds, which is extremely fast, the measured value distributions of both forward FW and reverse BW are different. A gap occurs. This deviation is also referred to as a peak-to-valley deviation of the profile of forward and backward movement, and is, for example, about 0.2 on the basis of a slice bolt. Previously, the scan speed of the sensor was almost fixed at the recommended value, but the scan speed has been gradually increased in response to the request for improvement in measurement accuracy. There is a problem that causes inconvenience in profile control.

Therefore, the present inventor has already disclosed in Japanese Patent Laid-Open No. 7-209.
No. 015 proposes a technique for compensating a sensor position using a position shift signal. However, when applied to an actual system, in the signal processing of each sensor, a smoothing process is performed to remove noise, but a time delay occurs accompanying the smoothing process. Then, superimposition on the difference in scan speed causes a hill-and-valley shift in the profile of forward and backward movement due to the smoothing process, and it is necessary to compensate for a time delay accompanying the smoothing process. SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and provides an apparatus capable of compensating for a time delay accompanying a smoothing process for removing noise and a difference in scan speed to compensate for a peak-valley deviation of a forward / backward profile. The purpose is to:

[0008]

The present invention, which achieves the above objects, comprises a sensor unit 20 having a plurality of sensors for measuring the basis weight, moisture content, and the like of paper produced by a paper machine process 10; A sensor driving means 30 for reciprocally scanning the sensor unit in the width direction of the sheet to be measured, and a flow direction signal removing filter for removing a flow direction component of the paper machine process from a measurement signal of each sensor housed in the sensor unit The scan type sensor having the following configuration is provided in a scan type sensor including a reference numeral 40 and a secondary sampling unit 50 for storing a signal output from the flow direction signal removal filter at predetermined intervals in a paper width direction.

That is, a frame and sensor data management processing section 200 for storing a predetermined interval DVX predetermined in the paper width direction, a sensor specification setting section 210 for storing a measurement system delay time unique to each sensor, The fixed response delay setting unit 220 that stores the time spent transmitting and receiving the measurement signal from the secondary sampling unit to the secondary sampling unit, and the time spent for the arithmetic processing in the secondary sampling unit, and the delay time due to the flow direction signal removal filter. A variable response delay setting unit 230 to be stored;
A response delay adding section 240 for adding the respective delay times stored in the fixed response delay setting section and the variable response delay setting section, a total delay time DLtotal obtained by the response delay adding section, and a sensor unit traveling speed of the sensor driving means. HDSPD
From the number of positional shift data ZUREtotal converted into constant intervals stored in the frame and sensor data management processing unit.
And a displacement data number compensator 250 for compensating the position data in the paper width direction corresponding to the measurement signal stored in the secondary sampling unit by the number of the displacement data, is provided. The profile of the measurement signal is generated based on the measurement signal and the position data compensated by the section.

[0010]

According to the structure of the present invention, the sensor specification setting section 21
0, the fixed response delay setting section 220 and the variable response delay setting section 230 have a measurement delay time unique to each sensor, a fixed response time delay determined by transmission and reception of measurement signals and arithmetic processing, and variable by a flow direction signal removal filter. , The response delay adding section 240 adds the response delay time to obtain the total delay time. The position shift data number compensating section 250 converts the total delay time into the position shift data number using the sensor unit traveling speed. Then, the position data in the paper width direction corresponding to the measurement signal stored in the secondary sampling unit is compensated based on the number of position shift data, and the time delay accompanying the smoothing process for noise removal and the scan speed are reduced. The difference is collectively compensated to compensate for the peak-valley deviation of the forward / backward profile.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG.
FIG. 1 is a configuration block diagram showing one embodiment of the present invention. In the figure, a sensor unit 20 accommodates a plurality of sensors for measuring the basis weight, moisture content, and the like of the paper manufactured by the paper machine process 10. The sensor driving unit 30 causes the sensor unit 20 to reciprocate in the width direction of the sheet to be measured, and also outputs a signal indicating the position of the sensor unit 20 in the width direction. Flow direction signal removal filter 40
Is to remove the component in the flow direction of the paper machine process 10 from the measurement signal of each sensor housed in the sensor unit 20. Since this calculation method has a zigzag running locus of the sensor with respect to the sheet, the measurement signal This is done by separating into two dimensions, the direction and the flow direction. The secondary sampling unit 50 stores the signal output from the flow direction signal elimination filter 40 as measured values of N measurement points provided at predetermined intervals (for example, 5 mm intervals) in the paper width direction. .

Frame and sensor data management processing unit 20
0 stores a predetermined constant interval DVX in the paper width direction. The sensor specification setting unit 210 stores a measurement system delay time unique to each sensor. For example, in the case of a grammage meter, a moisture meter, a thickness meter, and an ash meter, it is 50 milliseconds, and in the case of a color meter, Is about 1 second. Fixed response delay setting unit 2
Numeral 20 stores the time spent for transmitting and receiving the measurement signal from each sensor to the secondary sampling unit and the time spent for the arithmetic processing in the secondary sampling unit. To 10
Milliseconds, 0.1 milliseconds for arithmetic processing.

The variable response delay setting section 230 stores the delay time caused by the flow direction signal removal filter 40.
This delay time is, for example, 20 to 1000 milliseconds. The response delay adding section 240 includes the sensor specification setting section 210, the fixed response delay setting section 220, and the variable response delay setting section 23.
Each delay time stored in 0 is added. Based on the total delay time DLtotal obtained by the response delay adding unit 240 and the sensor unit traveling speed HDSPD of the sensor driving unit 30, the positional deviation data number compensating unit 250 converts the fixed interval conversion stored in the frame and sensor data management processing unit 200. The number of displacement data ZUREtotal is calculated, and the position data in the paper width direction corresponding to the measurement signal stored in the secondary sampling unit 50 is compensated for the number of displacement data. The number of displacement data ZUREtotal is obtained by the following equation.

ZUREtotal = (DLtotal * HDSPD) / (DVX) (1) For example, the delay time DLtotal of the sensor measurement system is 90
[Ms], running speed HDSPD =
When reciprocating at 20 [m / min] = 20/60 [mm / ms], when the total number of measurement points is 360 in the width direction, the measurement interval DVX = 6000/360 = 16.7 [m]
m], the number of displacement data ZUREtotal is 2 data according to the following equation. ZUREtotal = (90 [ms] * 20/60 [mm / ms]) / 16.7 [mm] = 1.8 (2)

FIG. 2 is an explanatory diagram of a structure for realizing the function of FIG. The sensor group 25 displays various sensors mounted on the sensor unit 20. Slave CPU 45
Performs an operation necessary for the flow direction signal removal filter 40 on the measurement signal of the sensor group 25. I / O card 5
Reference numeral 2 denotes a device for transmitting and receiving signals to and from the slave CPU 45, and transmits and receives measurement data according to a certain format called intra-frame communication here. The shared memory 54
This is a memory space shared between the I / O card 52 and the master CPU 56. The master CPU 56 performs an arithmetic function necessary for the secondary sampling unit 50 and an arithmetic function necessary for the misalignment data number compensating unit 250. The profile data storage unit 58 is a memory space for storing profile data created by the master CPU 56.

Next, the cause of the response delay used in the displacement data number compensator 250 will be described. FIG. 3 is a diagram for explaining the cause of the response delay. First, depending on whether the sensor is independent or common for each sensor, it is roughly classified into two types: a response delay of the sensor and a response delay of a measurement system other than the sensor. The former response delay items include those based on the principle of the detector and those based on electrical signal conversion, and the response delay is fixed in total, with a fixed delay time of 10 to 1000 milliseconds for each sensor. Has become. The latter response delay items include A / D conversion, intra-frame communication,
The / O card has processing to notify the master CPU and secondary sampling data processing.
0.1, 10, 0.1 and 0.1 milliseconds. The variable response delay of the latter is due to the flow direction signal elimination filter, and varies depending on the smoothing time of the filter.
It is variable in the range of 00 milliseconds.

Therefore, the sum of the response delay of the sensor itself and the response delay of the measurement system other than the sensor is obtained for each sensor, and the distance between the peaks and valleys of the profile is obtained by multiplying the sum by the traveling speed. Further, when the data is divided by the measurement interval, the number of peak / valley shift data in the profile can be calculated.

[0018]

As described above, according to the present invention, even if there is an element having a variable response delay time such as a flow direction signal elimination filter, the displacement data number compensating section 250 can be used.
By processing with other fixed response delay elements,
Since the peaks and valleys on the profile compensate for the phenomenon of deviation in the direction of travel of the sensor, only one calculation for compensation is required.
This has the effect of simplifying the calculation. In addition, even if the response speed is extremely slow compared to other sensors, such as a color meter that measures color and opacity, or a calcium meter, which is extremely slow compared to other sensors, it is a simple method to shift the profile and valley. There is also an effect that can be compensated.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram showing one embodiment of the present invention.

FIG. 2 is an explanatory diagram of a structure for realizing the functions of FIG. 1;

FIG. 3 is a diagram illustrating a cause of a response delay.

FIG. 4 is a diagram illustrating a relationship between a paper width direction and a measurement position.

FIG. 5 is a width distribution diagram of scan speed and forward / backward measured basis weight values.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Paper machine process 20 Sensor unit 30 Sensor drive part 40 Flow direction signal removal filter 50 Secondary sampling part 200 Frame and sensor data management processing part 210 Sensor specification setting part 210 220 Fixed response delay setting part 230 Variable response delay setting part 230 240 Response delay adder 250 Position shift data number compensator

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) G01D 3/00-4/18 D21F 7/00 D21F 7/06 G01B 21/00-21/32

Claims (1)

(57) [Claims] 1. A sensor unit (20) on which a plurality of sensors for measuring basis weight, moisture content, etc. of paper manufactured in a paper machine process (10) are mounted, and the sensor unit is connected to a width of the sheet to be measured. Sensor driving means (30) for reciprocating scanning in the direction, a flow direction signal removing filter (40) for removing a flow direction component of the paper machine process from a measurement signal of each sensor contained in the sensor unit, and a flow direction In a scan-type sensor having a secondary sampling unit (50) for storing a signal output from the signal removal filter at predetermined intervals in the paper width direction, a predetermined interval (DVX) in the paper width direction is determined. Frame and sensor data management processing unit to be stored (200)
A sensor specification setting unit (210) for storing a measurement system delay time unique to each sensor; a time spent for transmission and reception of a measurement signal from each sensor to a secondary sampling unit; and an arithmetic process in the secondary sampling unit Fixed response delay setting section (220) for storing the time spent for the measurement, variable response delay setting section (230) for storing the delay time due to the flow direction signal removal filter, sensor specification setting section, fixed response delay setting section A response delay adding unit (240) for adding each delay time stored in the variable response delay setting unit; and a total delay time (DLtotal) obtained by the response delay adding unit.
And the sensor unit traveling speed (HD
From the SPD), the number of positional displacement data (ZU) converted into a fixed interval stored in the frame and sensor data management processing unit.
REtotal), and a position shift data number compensator (250) for compensating position data in the paper width direction corresponding to the measurement signal stored in the secondary sampling unit by the number of the position shift data. A response speed compensator for a scan-type sensor, wherein a profile of the measurement signal is generated based on the measurement signal and the position data compensated by the position deviation data number compensator.