JP2644401B2 - Band-pass circuit used for control of rolling mill, and method of processing rolling load signal or thickness signal of rolling mill - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roll eccentricity removing control for reducing a thickness variation caused by an eccentricity of a rolling roll, which is generated from a rolling load signal or a thickness signal in the same cycle as a roll rotation cycle. A band-pass circuit used for extracting a fluctuation component due to roll eccentricity, and a fluctuation due to roll eccentricity generated in the same cycle as the roll rotation cycle from a rolling load signal or a thickness signal of a rolling mill. The present invention relates to a processing method for extracting components.

[0002]

2. Description of the Related Art One method of roll eccentricity removal control will be described with reference to FIG. In FIG. 1, 1 is a rolling mill, 10 and 11 are work rolls of the rolling mill 1, 12, 13
Is a backup roll of the rolling mill 1, and the plate material 3 rolled by the work rolls 10, 11 is wound by a winder (not shown).

[0003] The rolling load signal of the rolling mill 1 is obtained by a load cell 14 which is in contact with the upper backup roll 12, and the number of rotations of a motor (not shown) of the rolling mill 1 is obtained from a pulse generator. And the output side thickness fluctuation signal of the rolling mill 1 is detected by the radiation thickness gauge 4 comprising the radiation source 40 and the detector 41, respectively. Thickness control (hereinafter referred to as “AGC”) device 5 and roll eccentricity removal control (hereinafter “RE”)
C ". ) Input to the device 6. Reference numeral 2 denotes an input device, which is a target value of the output side plate thickness of the rolling mill 1 and other necessary data.
The input device 2 allows the AGC device 5
Is input to

[0004] In the AGC device 5, the thickness control output (roll gap) of the rolling mill 1 is obtained based on the detected ever-changing outlet sheet thickness and rolling load, and the target value of the outlet sheet thickness input from the input device 2. ) Is calculated. As described below, R
The EC device 6 calculates a roll gap correction value due to the roll eccentricity of the rolling mill, and supplies a roll gap correction signal based on the calculated roll gap correction signal to the AGC device 5, and the sheet thickness control output corrects the roll gap correction signal. By controlling the hydraulic pressure reduction cylinder 16 via the respective hydraulic pressure reduction control devices 17 using this as the final sheet thickness control output, the rolls 10 and 11 of the rolling mill 1 at each time are controlled. -The gap is properly set.

[0005] In the rolling mill 1 composed of four-stage rolls shown in Fig. 6, the diameter of the upper and lower rolls 10, 11 and the diameter of the upper and lower backup rolls 12, 13 are the same. Therefore, since the rotational frequencies of the rolls 10, 11 and the rolls 12, 13 are always the same, they correspond to the upper and lower work rolls 10, 11 and the upper and lower backup rolls 12, 13, respectively. REC to process the rolling load signal
The device 6 uses a circuit in which two band-pass filters, each having a pass band set as shown in FIG. 7, are connected in parallel.

[0006] The rolling loads of the upper and lower rolls 10, 11, 12 and 13 during rolling are detected by a load cell 14, and the respective rolling load signals output from the load cells 14 are output from a rotation speed detector 1
The rotation frequency value of each roll detected by the frequency calculation circuit (not shown) is input to the band-pass filters BPF1 and BPF2 shown in FIG. 7, and the rolling loads are applied to the filters BPF1 and BPF2. From the signals, only the fluctuation signals (the eccentric components of the work rolls 10 and 11 and the eccentric components of the backup rolls 12 and 13) generated in synchronization with the roll rotation period are extracted and extracted. Add and output.

[0007] The fluctuation signal output from the band-pass filters BPF1 and BPF2 as described above is regarded as a fluctuation component due to roll eccentricity.
The output fluctuation signal is multiplied by a conversion coefficient to a roll gap determined in consideration of the elastic modulus of the mill and the plasticity coefficient of the material, and converted into a roll gap fluctuation. A gap control signal calculated by the AGC device 5 with the correction value,
Control is performed so as to eliminate the thickness variation due to the eccentricity of the roll of the rolling mill 2.

[0008]

As shown in FIG. 7, a plurality of band-pass filters BPF1 and BPF1 corresponding to a plurality of frequencies are provided.
When signal processing is performed using a circuit in which PF2s are connected in parallel, if a plurality of roll eccentric components are close and unequal in frequency, the roll eccentric components cannot be accurately extracted. In addition, the effect of the roll eccentricity removal control is remarkably impaired, and the thickness accuracy is reduced.

That is, as shown in FIG. 8, the input to the band-pass filters BPF1 and BPF2 includes other components Ce composed of various components in addition to the eccentric component frequencies Cf1 and Cf2 of the roll. Eccentric component frequencies Cf1 and Cf
2 are close to each other, one of the filters BPF1
When passing the eccentric component frequency Cf1, components g1 and Cf2 (where 0 <g1 <1) in which the other eccentric component frequency Cf2 is reduced leak out. Similarly, when passing the eccentric component frequency Cf2 from the other filter BPF2, the other component eccentric component Cf1 has a reduced component g2 · Cf1 (where 0 <g2 <1).
Leaks out. Then, these are added and Cf1 + Cf2
When output from the circuit as + (g1 · Cf2) + (g2 · Cf1), the leaked component (g1 · Cf2) + (g
2 · Cf1) becomes noise and distorts the output waveform. The input waveform in such a case is illustrated in FIG. 9 and the output waveform is illustrated in FIG. 10. When the two waveforms are superimposed for comparison, the difference between the two waveforms is large as apparent from FIG. The effect of the roll eccentricity removal control is significantly impaired.

An object of the present invention is to provide a band-pass circuit and a signal processing method capable of extracting a plurality of eccentric components more faithfully even when a plurality of eccentric component frequencies are very close to each other. It is in.

[0011]

According to the band pass circuit used for controlling the rolling mill according to the present invention, in order to achieve the above-mentioned object, one of the parallel circuits includes a plurality of bands corresponding to a plurality of frequencies. It is characterized in that removal filters are connected in series. Further, the signal processing method according to the present invention, a signal due to rolling load fluctuation or plate thickness fluctuation, while input to a plurality of band elimination filters connected in series corresponding to a plurality of frequencies to one of the parallel circuit, The other output of the parallel circuit, the final output of the plurality of band rejection filters,
It is characterized in that it is removed from the other input signal of the parallel circuit.

[0012]

According to the band-pass circuit and the signal processing method of the present invention, when a plurality of rolling load signals and sheet thickness signals are input to the circuit, the first band-elimination filters connected in series are used for the first band-elimination filter. Is removed, the second eccentric component frequency is removed by the second band elimination filter, and the same processing is sequentially performed thereafter. The Nth eccentric component frequency is removed by the final Nth band elimination filter. As a result, the final output is only a component other than the eccentric component. Then, the final output from the final band elimination filter is removed from the input signal input to the other side of the parallel circuit, so that only a plurality of eccentric components are output from the circuit. In this way, even when a plurality of frequencies are very close to each other, the influence of each eccentric component is extremely small.

A preferred embodiment of the band pass circuit and the signal processing method according to the present invention will be described with reference to FIGS. FIG. 1 is a block diagram of a roll eccentricity elimination control device for explaining this embodiment, FIG. 2 is an exploded view showing a state in which signal processing is performed in a bandpass circuit according to this embodiment, FIG. 4 is a diagram showing an example of an input waveform to the band-pass circuit according to this embodiment, FIG. 4 is a diagram showing an example of the output waveform, and FIG. 5 is a diagram in which both waveforms are overlapped to compare the input waveform and the output waveform It is. In the following example,
Assuming that the diameter difference between the upper and lower backup rolls 12, 13 is 10%,
The case of extracting the eccentric component from each rolling load signal of No. 3 will be described.

The load cell 14 of the rolling mill 2 illustrated in FIG.
Load signal (backup roll 12
1 and the eccentric component signal of the backup roll 13) are input to a subtractor 60 having a memory 61 as shown in FIG. This memory 61 stores the rolling load at the start of rolling, and the initial rolling load amount is subtracted from the rolling load signal output from the load cell 14, and the output is used as the band pass circuit 64 of this embodiment. Is input to

The band-pass circuit 64 includes parallel circuits 64a, 6
4b, on the other hand, band rejection filters BCF1 and BCF2 in which rejection bands are set corresponding to the two kinds of rolling load signals are connected in series to 64b. To the band elimination filters BCF1 and BCF2, the rotation frequencies of the backup rolls 12 and 13 obtained by calculating the output of the rotation speed detector 15 in FIG.

As shown in FIG. 2, the eccentric component signal frequency Cf1 of the backup roll 12, the eccentric component frequency Cf2 of the backup roll 13, and the rolling load signal including the other components Ce are input to the band elimination filter BCF1. From the rolling load signal, the roll 1 synchronized with the rotation of the roll is used.
The eccentric component frequency Cf1 corresponding to 2 is removed. Since the diameter difference between the backup rolls 12 and 13 is small as described above and the frequencies Cf1 and Cf2 are close to each other, the band elimination filter BCF1 corresponds to the other roll 13 together with the other components Ce from the band elimination filter BCF1. Eccentric component frequency Cf2
Is a small frequency g1 · Cf2 (where
0 <g1 <1) are simultaneously output.

The output of the band elimination filter BCF1 is input to the next band elimination filter BCF2, and by this filter BCF2, the frequencies g1 and Cf2 partially including the eccentric component frequency Cf2 synchronized with the rotation of the roll out of the filter BCF2. It is removed and only the other component Ce is output from the filter BCF2. Then, the other component Ce, which is the final output, is removed from the rolling load signal input to the other one 64a of the band-pass circuit 64 in FIG.
And Cf2 are output from the bandpass circuit 64 only.

FIG. 3 shows an example of the input waveform of the band-pass circuit 64 when the signal processing is performed as described above, and FIG. 4 shows the output waveform thereof. As shown in FIG. 5, the difference between the input and output waveforms is extremely small. Therefore, the two eccentric components can be extracted almost exactly, and the accuracy of the roll eccentricity removal control is improved.

The combined fluctuation signal to which only the eccentric component frequencies Cf1 and Cf2 are added is input to a multiplier 62, and the input is multiplied by a conversion coefficient to a roll gap stored in a memory 63 to obtain a roll gap. The output signal of the multiplier 62 is converted into a fluctuation signal, a control gain is added to the output of the multiplier 62 by a multiplier 66, the phase is converted by a multiplier 67, and the AGC device 5 of FIG.
Supplied to The AGC device 5 corrects the thickness control output based on the roll gap correction signal.

In the above embodiment, the conversion of the rolling load signal into a roll gap fluctuation signal by the multiplier 62 can be performed even before the signal is processed by the band pass circuit 64. When processing the output side thickness variation signal, the thickness variation signal is obtained from the thickness gauge 4 in FIG. 6, and the signal is processed by the band-pass circuit 64 in the same manner as in the above-described embodiment. Only the fluctuation component of the same cycle is extracted.

In the above embodiment, the backup row
Although the example of processing the rolling load fluctuation of only the rolls 12 and 13 has been described, in a rolling mill having more multi-stage rolls than that illustrated in FIG. 6, a roll eccentric component is generated by three or more elements. In this case, three or more band rejection filters of FIG. 1 are connected in series correspondingly.

[0022]

According to the band pass circuit and the method for processing the rolling load signal or the thickness signal according to the present invention, each component is faithfully reproduced from a plurality of periodic fluctuation components due to roll eccentricity. Since it can be extracted as a composite signal, when applied to roll eccentricity removal control of a rolling mill, roll eccentricity removal control can be performed with higher accuracy, and the product thickness accuracy, which is a product, is further improved. Can be done.

[Brief description of the drawings]

FIG. 1 is a block diagram of a roll eccentricity removal control device for explaining an embodiment of the present invention.

FIG. 2 is an exploded view showing a state in which signal processing is performed in the band pass circuit according to the embodiment.

FIG. 3 is a diagram illustrating an example of an input waveform to a bandpass circuit according to the embodiment.

FIG. 4 is a diagram showing an example of an output waveform from a bandpass circuit according to the embodiment.

FIG. 5 is a diagram in which the input waveform of FIG. 3 and the output waveform of FIG. 4 are superimposed.

FIG. 6 is a block diagram showing an example of an automatic thickness control device including a roll eccentricity removal control device of a rolling mill.

FIG. 7 is a schematic diagram showing a conventional filter circuit used for controlling a rolling mill.

8 is an exploded view showing a state where signal processing is performed by the filter circuit of FIG. 7;

FIG. 9 is a diagram illustrating an example of an input waveform to the filter circuit of FIG. 7;

FIG. 10 is a diagram illustrating an example of an output waveform from the filter circuit of FIG. 7;

11 is a diagram in which the input waveform of FIG. 9 and the output waveform of FIG. 10 are superimposed.

[Description of Signs] 1 Rolling machine 10, 11 Work roll 12, 13 Backup roll 14 Load cell 15 Rotational speed detector 16 Hydraulic pressure reduction cylinder 17 Hydraulic pressure reduction device 2 Input device 3 Sheet material 4 Sheet thickness gauge 40 Source 41 Detector 5 Automatic plate pressure control device 6 Roll eccentricity removal control device 60 Subtractor 61, 63 Memory 62, 66, 67 Multiplier 64 Bandpass circuit 64a The other of the parallel circuits 64b One of the parallel circuits 65 Rotation frequency Arithmetic unit BCF1, BCF2 Band-elimination filter BPF1, BPF2 Band-pass filter

Claims (2)

(57) [Claims] 1. A band-pass circuit used for controlling a rolling mill, wherein a plurality of band-elimination filters corresponding to a plurality of frequencies are connected in series to one of the parallel circuits. 2. A signal due to rolling load variation or plate thickness variation is input to a plurality of band elimination filters connected in series to one of the parallel circuits corresponding to a plurality of frequencies,
A method for processing a rolling load signal or a sheet thickness signal of a rolling mill, wherein the signal is input to the other of the parallel circuits and a final output of the plurality of band elimination filters is removed from the other input signal of the parallel circuit. .