JPH0215675B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention provides a method for controlling the profile of absolute dry basis weight (weight per 1 m ² excluding water, expressed in g/m ² ) in a paper machine control device. This invention relates to a device for controlling the opening degree of a slice lip to match a desired profile.

<Prior Art> The configuration of a papermaking control device and its problems will be explained with reference to FIGS. 5 to 11. Figure 5 shows the overall configuration, 1 is a seed box, 2 is a seed opening valve, 3 is a fan pump, 4 is a stock inlet, 5 is a slice lip, 6 is a wire part, 7 is a suction box, and 8 is a Spray part, 9 is dryer, 10
11 is a calendar, 11 is a reel, 12 is paper that becomes a product wound on the reel, and 13 is a silo for collecting white water. Reference numeral 14 denotes a basis weight sensor that scans the product 12 in the width direction to measure its basis weight and moisture content, and is realized by, for example, a combination of a β-ray basis weight meter and a near-infrared moisture meter. Reference numeral 15 denotes a control device that processes information from the sensor to calculate the profile of the absolute dry basis weight in the width direction of the product, and operates the seed opening valve 2 and the slice lip according to the deviation from the desired profile pattern. send a signal. Further, an operation signal is also sent to the dryer 9 in order to manage the moisture content.

Fig. 6 is a perspective view of the stock inlet 4, slice lip 5, and wire part 6, and Fig. 7 is a partially enlarged view of the slice lip 5. The slice lips 5 are lined up at a constant pitch (100 to 150 mm). A plurality of slice bolt groups 16 ₁ attached with
The opening pattern of the gap 17 caused by the slice lip 5 can be finely adjusted by manipulating the amount of delivery of each of the slice lips 16 ₂ , . . . 16 _o . Reference numerals 18 and 19 are no deckles provided to prevent the paper stock discharged from the end of the slice lip from being discharged to the outside of the wire part.

Figure 8 is a diagram explaining the basic operation, and the horizontal axis is the paper width l.
The vertical axis represents the absolute dry basis weight BD. S ₁ , S ₂ ,...S _o
indicates the positions corresponding to the slice bolt groups 16 ₁ , 16 ₂ , . . . 16 _o . E _p is the measurement profile of the absolute dry basis weight calculated based on the information from the sensor, _p is its average value, and S _p is the desired setting profile of the absolute dry basis weight. The opening degree of the seed opening valve 2 is controlled by an operation signal based on the deviation between _p and S _p , and when _p matches S _p , the deviation between the desired profile and the measured profile ε ₁ ,
The opening degree of the slice lip is controlled via each slice bolt group based on ε ₂ ,...ε _o . Adjustment of the slicing bolt causes deformation of the slicing lip in that portion, changing the amount of paper stock discharged, and thus changing the absolute dry basis weight. Therefore, by adjusting the plurality of slice bolt groups based on the deviation in each bolt position, it is possible to control the slice bolts to accurately match the desired profile.

The absolute dry basis weight BD is measured at a certain sample time, and the deviation from the set profile is calculated for each point corresponding to the sliced bolt. Letting the deviation signal at the k-th slice bolt position S _k be ε _k ,
In order to cancel this deviation signal, the slice bolt position operation signal u _k is calculated by the PI operation of the following equation.

u _k = K _p (ε _k +1/T _I Σε ⁱ _k ) (1) Here, K _p and T _I are proportional and integral constants, and Σε ⁱ _k
is the sum of the deviation signals ε _k from the past to the present, and corresponds to an integral operation. Note that this position operation signal
Uk provides a motion component that smoothes the profile shape of the absolute dry basis weight in the width direction and longitudinal direction of the paper. In order to bring the measured value closer to the desired absolute dry basis weight, the seed opening valve is operated to bring the absolute dry basis weight closer to the desired absolute dry basis weight.

Since ε _k in the above equation concerns only the variation in the width direction, and does not concern its average value, specifically, it is calculated as follows. As shown in Fig. 9A, when e _k is the deviation between the measured absolute dry basis weight and the set value at the slice bolt position S _k , e _k = P _sk − P _nk (k = 1, 2,...n ) (2) = 1/n _o 〓 ^k=1 e _k (3) ε _k = e _k − (4) Here, P _sk and P _nk are the set value of absolute dry basis weight at the slice bolt S _k position and measured values, e _k is their deviation,
e is the average value of the deviation.

Based on the deviation signal ε _k determined in this way,
Slice bolt position operation signal calculated by formula (1)
The profile of u _k is as shown in FIG. 9B, but only the relative value of this position operation signal is managed, and the absolute value is not defined. Therefore, since the value of each signal is determined by the magnitude of the deviation signal ε _k and the integral value from the past, it is not possible to specify what value the level of the average value expressed by the following equation takes.

=1/n _o 〓 ^k=1 u _k (5) The slice lip 5 is a continuous plate, and its average movable range is limited, and there are upper and lower limits of operable positions. Therefore, if the slice bolt is operated by directly receiving the operation signal of the calculated position, there is a risk that excessive force will be applied to the slice lip or it will be damaged.

<Problems to be Solved by the Invention> An object of the present invention is to provide a control device equipped with means for preventing the profile of a position operation signal for a slice bolt from exceeding the allowable profile of the slice lip.

<Means for Solving the Problems> The first feature of the configuration of the apparatus of the present invention is that the paper material to be discharged onto the wire part from the stock inlet is controlled by the opening degree of the slicing screw at a plurality of locations on the slicing lip. In a paper machine control device that controls the absolute dry basis weight to a desired profile by adjusting the Comprising a calculation means for calculating a bolt position operation signal, a parallel movement means for moving the profile of the position operation signal in parallel upward and downward, and a comparison means for comparing the average value of the position operation signal with a set value. The present invention is characterized in that the parallel movement means is controlled based on the output of the comparison means.

The second structural feature of the device of the present invention is that the stock discharged from the stock inlet onto the wire part is adjusted by controlling the opening of the slicing screw at multiple locations on the slicing lip to achieve the desired absolute dry basis weight. A paper machine control device for controlling a paper machine to a profile that is controlled to a profile, comprising: a means for measuring absolute dry basis weight; and a calculating means for calculating a position operation signal for the slice bolt based on a deviation profile between the measured profile for the absolute dry basis weight and a desired profile. and a parallel movement means for moving the profile of the position operation signal in parallel upward and downward, and a comparison means for comparing each of the position operation signals with an upper limit setting value and a lower limit setting value, and an output of the comparison means. If any of the position operation signals exceeds the upper limit set value or the lower limit set value based on If the signal exceeds the upper limit value or the lower limit value, the exceeded signal is clipped at the set value and the parallel movement means is not controlled.

<Effect> For the calculated position operation signal u _k , its average value _k
is calculated, the average value is compared with the set value, and based on the result, the profile of the position operation signal is translated in an upward or downward direction, and the average value is controlled to match the set value. Or, each of the position operation signals is compared with the upper limit setting value and the lower limit setting value, and when either exceeds this setting value, the position operation signal profile is translated downward or upward, and the operation signal exceeds the set value. controlled so as not to occur. In this case, if there is an operation signal that exceeds both the upper and lower set values, the parallel movement operation is not executed and the portion that exceeds the set values is clipped.

<Embodiment> An embodiment of the present invention will be described based on the overall configuration diagram in FIG. 1 and operation explanatory diagrams in FIGS. 2 to 4. In FIG. 1, F is the field side, and has a paper machine M having a slicing lip 5 and a basis weight sensor 14 for measuring the basis weight of the paper 12. R is control device 1
5 on the control room side. In the control device 15, 151 is means for calculating bone dry basis weight BD based on information from basis weight sensor 14, E _p is a measurement profile of bone dry basis weight BD in one measurement batch, S _p is a setting profile, and 152 is a means for calculating bone dry basis weight BD based on information from basis weight sensor 14; The deviation holding means outputs a profile ε _p of the deviation signal ε _k calculated by equation (4) for each measurement batch in synchronization with the measurement batch signal e _b . 153 is a calculation means that calculates the position operation signal of each slice bolt according to equation (1) and outputs a profile u of the position operation signal. Reference numeral 154 denotes parallel value calculating means, which calculates the average value of u based on equation (5). 1
55 is a comparison means that compares the set average value _s and
Based on the comparison result, a parallel movement operation signal e _s1 is transmitted. Reference numeral 156 denotes a parallel movement means that receives e _s1 and moves u upward or downward in parallel. The value u _k ′ of the position operation signal u _k at the S _k position after translation is given by u _k ′=u _k −(− _s ) (6).

FIG. 2 is an explanatory diagram of the parallel movement operation, in which a downward movement operation in the direction of arrow A is executed based on the difference between the average value of the position operation signal u shown by the solid line and the set average value u _s , and the profile shown by the dotted line is Shift parallel to u′ and make its average value match _s . Such an operation makes it possible to always regulate the average value of the position operation signal to the slice bolt to a constant set average value _s .

Next, the dotted block B is means for monitoring the upper and lower limits of the position operation signal, and 157 is an upper and lower limit comparing means, which receives the output u of the calculation means 153 or the output u' of the parallel movement means 156, and The value of the operation signal is compared with the upper limit setting value u _H and the lower limit setting value u _L , and the parallel movement operation signal e _s2 is transmitted based on the comparison result. 158 is a parallel movement/clipping means, e _s2
In response to this, u or u' is translated upward or downward, or clipped at the upper or lower limit setting value. u'' is a position operation signal profile after parallel movement or clipping, and based on this profile, the slice bolt group is operated and the opening degree pattern of the slice lip 5 is changed.

3 and 4 are explanatory diagrams of the operation in block B. As shown _{in FIG} . A parallel movement operation such as
u′ is translated downward to a profile u″ such that u′ _k becomes a value u″ _k that is less than the upper limit setting value u _H . If the lower limit setting value is exceeded, parallel movement is performed upward in the same way.

Next, as shown in Figure 4, if u' _k of the position operation signal profile u' exceeds the upper limit set value u _H and u' _n exceeds the lower limit profile u _L , the parallel movement operation will not be executed. A clipping operation is performed, converting u' _k to the upper setting value u _H and u' _n to the profile u'' clipped to the lower setting value u _L.

In the device of the present invention, the operation of moving the average value of the position operation signal in parallel to the set average value and the parallel movement or clipping operation based on the comparison result with the upper and lower limit set values are both performed in a cascade as in the above embodiment. It is also possible to implement only one of them.

Moreover, the method for realizing each means in the control device 15 is as follows.
It may be configured by hardware, or the functions of each means can be easily realized by software functions using a computer.

<Effects> As explained above, according to the present invention, the profile of the position operation signal for the slice bolt always maintains a constant average position and is supplied without exceeding the upper or lower limits. Manipulation is prevented, and profile control based on bone dry basis weight can be stably performed.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the device of the present invention;
Figures 2 to 4 are explanatory diagrams of its operation, Figures 5 and 6 are configuration diagrams of the paper machine control device, Figure 7 is an enlarged configuration diagram of the slice rip portion, and Figures 8 and 9 are diagrams of the apparatus. FIG. 5... Slice lip, 12... Paper, 14... Basis weight sensor, 15... Control device, 151... Absolute dry basis weight calculation means, 152... Deviation holding means, 153... Calculating means,
154... Average value calculation means, 155... Comparison means, 1
56... Parallel movement means, 157... Upper and lower limit comparison means,
158...Parallel movement/clipping means.

Claims (1)

[Scope of Claims] 1. Paper making in which the absolute dry basis weight is controlled to a desired profile by adjusting the paper stock discharged onto the wire part from the stock inlet by controlling the opening of the slicing screw at a plurality of locations in the slicing lip. In the machine control device, a means for measuring bone dry basis weight, a calculation means for calculating a position operation signal of the sliced bolt based on a deviation profile between a measurement profile of the bone dry basis weight and a desired profile, and a means for calculating the position operation signal for the slice bolt. comprising a parallel movement means for parallelly moving the profile upward and downward, and a comparison means for comparing the average value of the position operation signal with a set average value, and the parallel movement means is provided based on the output of the comparison means. An absolute dry basis weight profile control device. 2. In a paper machine control device that controls the absolute dry basis weight to a desired profile by adjusting the stock discharged from the stock inlet onto the wire part by operating the opening degree of the slice screw at multiple locations on the slice lip, a means for measuring dry basis weight; a calculating means for calculating a position operation signal for the sliced bolt based on a deviation profile between a measurement profile for absolute dry basis weight and a desired profile; and a comparison means for comparing each of the position operation signals with an upper limit setting value and a lower limit setting value, and one of the position operation signals is set to the upper limit based on the output of the comparison means. If the value or lower limit set value is exceeded, the parallel moving means is controlled to move the position operation signal profile downward or upward in parallel, and if any of the position operation signals exceeds the upper limit set value or the lower limit set value. An absolute dry basis weight profile control device characterized by clipping a signal exceeding the set value at a set value and not controlling a parallel movement means.