JP3799701B2 - Rotating position control device for laying head - Google Patents

Description

【００３１】
これを更にスケーリングしたものをレイングヘッド３の回転速度の制御量とする。そして、レイングヘッド３の回転速度の基準値を設定する回転速度設定手段１７から出力される基準速度に上記制御量を加えたものを指示速度としてモータ５のドライブ装置６に与える。
【００３２】
線材１の先端がセンサ９により検出されると、ここで先端位置を補正し、制御を続ける。仕上圧延機２の入側に設けられたセンサ８のところから制御を開始することにより、制御時間が確保される。
【００３３】
このようにしてレイングヘッドの回転位置を制御した場合の制御出力の経時的な変化を図８に示す。図３との比較から明らかなように、本発明の場合はＰＩ制御を用いた従来の場合よりも短時間で吐出口が目標位置に制御され、レイングヘッド３の回転速度が基準値に戻る。その結果、線材先端の落下位置精度が向上する。また、線材１の先端が吐出口に到達した後におけるレイングヘッド３の回転速度の変動が抑制されることにより、線材先端部のコイル形状の悪化が回避される。
【００３４】
図９（ａ）は線材先端の落下位置のばらつきを本発明の場合とＰＩ制御を用いる従来の場合とについて示す図表である。本発明の方が、低速から高速まで落下位置精度が高く、特に高速圧延でその効果が顕著である。また、図９（ｂ）は線径５．５ｍｍ、速度６０ｍ／ｓで圧延を行う場合の制御終了時（線材先端が吐出口に到達した時点）におけるレイングヘッドの回転速度偏差を示す図表である。本発明により、レイングヘッドの回転速度偏差が約１／５に減少し、線材先端部のコイル形状は手入れが不要なレベルまで改善された。
【００３５】
【発明の効果】
以上の説明から明らかなように、本発明のレイングヘッドの回転位置制御装置は、レイングヘッドの回転速度の制御量を演算する際に、制御角度、制御角度の変化率及び線材先端からレイングヘッドの吐出口までの残距離のうちの、少なくとも制御角度を含む１以上の因子を用い、その因子が大きいほどゲインを大きくすることにより、ゲインが一定の従来制御よりも制御時間が短くなるので、線材の進行速度が速い場合も、線材先端がレイングヘッドの吐出口に到達する時点までに制御を完了させることができる。従って、線材の進行速度が速い場合も、線材の先端を決められた位置へ正確に落下させることができる。また、線材先端がレイングヘッドの吐出口に到達する時点までにレイングヘッドの回転速度が基準値に復帰することにより、線材先端部のコイル形状の悪化を回避することができる。
【図面の簡単な説明】
【図１】線材の製造ラインを示す模式図である。
【図２】レイングヘッドの吐出口の回転位置を示す模式図である。
【図３】ＰＩ制御を用いてレイングヘッドの回転位置を制御する場合の制御出力の経時的な変化を示す図表である。
【図４】本発明の実施の形態に係る制御装置の構成図である。
【図５】制御量の演算に使用されるファジー推論に用いられるメンバーシップ関数の説明図である。
【図６】同ファジー推論に用いられるファジールールの説明図である。
【図７】同ファジー推論の具体的手順を説明するためのメンバーシップ関数の説明図である。
【図８】ファジー制御を用いてレイングヘッドの回転位置を制御する場合の制御出力の経時的な変化を示す図表である。
【図９】本発明の効果を示す図表である。
【符号の説明】
１ 線材
２ 仕上圧延機
３ レイングヘッド
４ コンベア
５，７ モータ
６ ドライブ装置
８，９ 先端センサ
１０，１１，１２ パルスジェネレータ
１３ 回転位置予測手段
１４ 回転位置検出手段
１５ 回転位置設定手段
１６ 制御量演算手段
１７ 回転速度設定手段[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rotational position control device for a laying head used in a wire production line or the like.
[0002]
[Prior art]
In the manufacture of the wire rod, as shown in FIG. 1, the hot tube rolling is finished, and the wire rod 1 from the finishing mill 2 is sent to the laying head 3. The laying head 3 rotates at the same speed as the traveling speed of the wire 1, thereby forming the wire 1 into a coil shape and discharging it onto the conveyor 4. The coil-shaped wire 1 that continuously falls on the conveyor 4 is transported in an overlapping manner in a state of being shifted in the radial direction, and is cooled in the process.
[0003]
In coil forming of the wire 1 using the laying head 3, it is an important technical problem to drop the tip of the wire 1 to a predetermined position on the conveyor 4. That is, when the tip of the wire 1 falls on the conveyor 4, if the tip faces forward in the transport direction, the tip is caught by a chain or the like, and the wire 1 is hardened in a dumpling shape. The tip drop position of the wire 1 is controlled so as to face in the rearward direction. This control is conventionally performed as follows.
[0004]
The tip position of the wire is tracked from the elapsed time from the start of control and the traveling speed of the wire. The rotation position of the discharge port when the tip of the wire reaches the discharge port of the laying head is predicted every moment, and the current rotation position of the discharge port of the laying head is detected every moment. The rotational speed of the laying head is controlled so that the deviation angle between the target rotational position of the discharge port and the predicted rotational position required to drop the tip of the wire rod to the target position becomes zero.
[0005]
That is, as shown in FIG. 2, if the current position of the ejection head of the laying head is P, the predicted position of the ejection port when the tip of the wire reaches the ejection port is Py, and the target position of the ejection port is Po, When the rotational speed of the laying head is maintained, when the tip of the wire reaches the discharge port, the current position P rotates by R and moves only to the predicted position Py. An insufficient angle is produced. Therefore, the rotational speed of the laying head is changed from the reference value (accelerated in the figure) so that the deviation angle θ between the predicted position Py and the target position P is 0, so that the predicted position Py matches the target position Po. is there.
[0006]
By the way, in such a rotational position control of the laying head, the deviation angle θ between the predicted position Py of the discharge port and the target position Po is set to 0 by the rotational speed control of the laying head. It does not mean that the amount of rotation is controlled. The deviation angle θ is set as a control angle, and the control angle multiplied by a predetermined ratio is set as a control amount of the rotational speed of the laying head. The ratio here is called a gain, and feedback control using this gain is called PI control.
[0007]
The rotational position control of the laying head that controls the rotational speed of the laying head so that the deviation angle θ is zero while detecting the deviation angle θ between the predicted ejection position Py of the laying head and the target position Po is, for example, No. 52-15250, Japanese Patent Application Laid-Open No. 61-123417, etc., all controls are PI controls.
[0008]
[Problems to be solved by the invention]
However, when the rotational position of the laying head is controlled using PI control, there are the following problems. FIG. 3 shows changes with time in the control output when the rotational position of the laying head is controlled using PI control.
[0009]
When controlling the rotational position of the laying head using PI control, as shown in FIG. 3, the rotational speed of the laying head is increased at the initial stage of control when the deviation angle θ between the predicted position Py and the target position Po, which is the control angle, is large. The rotation position (current position P) of the discharge port suddenly approaches the target position Po. As the control proceeds, the deviation angle θ decreases, so that the rotational speed control amount also decreases. Finally, the deviation angle θ becomes 0 and the rotational position of the discharge port (current position P) becomes the target position. Matches Po. At the same time, the rotational speed of the laying head returns to a reference value equal to the traveling speed of the wire.
[0010]
The ideal control pattern in this case is that the rotational position (current position P) of the ejection port matches the target position Po until the tip of the wire reaches the ejection port of the laying head, as shown by the solid line in FIG. The rotational speed of the laying head is returned to a reference value equal to the traveling speed of the wire. In order to obtain this change pattern, a specific gain is selected based on the manufacturing conditions of the wire.
[0011]
However, in actual wire manufacturing, operating conditions are changed and there are variations. It is impossible to change the gain one by one in response to these fluctuations. For this reason, the selected gain deviates from the ideal value, and there are cases where it is excessive and insufficient. Previously, the production speed of the wire rod was slow, and even if the selected gain deviated from the ideal value, no significant problem occurred. However, recently, the production speed of the wire has increased remarkably, and it is not possible to secure a sufficient time for controlling the rotational position of the discharge port. Therefore, the deviation of the gain from the ideal value causes the following problem.
[0012]
When the selected gain is excessive, as shown by a broken line in FIG. 3, the amount of control of the rotational speed of the laying head is 0 when the leading end of the wire reaches the ejection port of the laying head as a remnant of rapid control. do not become. Even when the selected gain is insufficient, as shown by a two-dot chain line in FIG. 3, the control amount is delayed, so that when the leading end of the wire reaches the ejection port of the laying head, the amount of control of the rotational speed of the laying head is reduced. Does not become zero. As a result, in any case, the rotational speed of the laying head deviates from the reference value for a while after the leading end of the wire reaches the ejection port of the laying head.
[0013]
While the inventors have continued research to accurately drop the tip of the wire to a predetermined position, the inventors have been studying to improve the coil shape of the wire, but rotation of a conventional laying head using PI control In position control, even if the drop position of the wire tip can be accurately controlled, deterioration of the coil shape of the wire tip cannot be avoided, and the cause of the deterioration is indicated by a broken line or a two-dot chain line in FIG. It has been found that the rotation speed of the laying head that continues after the tip of the laying head reaches the ejection port of the laying head is unstable.
[0014]
That is, until the leading end of the wire reaches the ejection port of the laying head, the deviation of the laying head rotational speed from the reference value does not affect the coil shape at all. However, after the tip of the wire reaches the ejection port of the laying head, that is, in the process of discharging the wire from the ejection port, the rotational speed of the laying head deviates from the reference value (equal to the traveling speed of the wire), The winding diameter of the coil changes from its reference value. For this reason, until the rotational speed of the laying head stabilizes at the reference value, the shape of the coil deteriorates at the tip of the wire.
[0015]
Recently, the wire manufacturing speed has become very fast. For this reason, even after the tip of the wire rod reaches the ejection port of the laying head, the rotational speed of the laying head often continues to fluctuate, and the coil shape at the tip of the wire rod is significantly deteriorated. If the amount of the fall of the wire tip is small, there will be no problem in actual operation. However, the deterioration of the coil shape at the tip of the wire will cause problems such as catching troubles in the coil integrated device and deterioration of the product packaging. Therefore, it is considered more important to prevent deterioration of the coil shape at the tip of the wire in the production of the wire in the future.
[0016]
An object of the present invention is to provide a laying head that can accurately drop the tip of the wire to a predetermined position even when the traveling speed of the wire is high, and can avoid deterioration of the coil shape of the tip of the wire. It is to provide a rotational position control device.
[0017]
[Means for Solving the Problems]
The rotational position control device for a laying head according to the present invention includes a means for rotationally driving a laying head for forming a wire passing through the inside into a coil shape by rotational movement and discharging it from a discharge port, and a wire rod by tracking the tip position of the wire. Means for predicting the rotational position of the ejection port when the tip reaches the ejection port of the laying head, means for detecting the current rotational position of the ejection port, and matching the predicted rotational position of the ejection port to the target position A means for obtaining the control angle of the laying head necessary for the control, and one or more factors including at least the control angle among the control angle, the rate of change of the control angle, and the remaining distance from the wire rod tip to the discharge port of the laying head converting mechanism calculates the control amount of the rotational speed of the laying head, and means for increasing the gain as the factor is larger when performing the calculation, the calculated control And means for controlling the rotational speed of the laying head at.
[0018]
In the present invention, basically, the control angle of the ejection port of the laying head is set to 0, and the rotational position of the ejection port is made to coincide with the target position. The difference is that when calculating the control amount of the rotational speed of the laying head, one or more factors including the control angle are used, and the gain (ratio of the control amount to the factor size) increases as the factor increases. Is to do. That is, when the factor is the control angle, the gain is increased at the initial stage of the control when the control angle is large, and the control is performed with high sensitivity, and the gain is decreased as the control angle decreases as the control progresses. Is reduced. By doing this, the control time is shorter than in the conventional control with a constant gain, and even when the wire travel speed is fast, the control is completed by the time the wire tip reaches the ejection port of the laying head, and the wire tip Is accurately dropped to the determined position, and deterioration of the coil shape at the tip of the wire is avoided.
[0019]
Specifically, for example, fuzzy inference can be used for the calculation of the control amount. The factors used when calculating the control amount are specifically “control angle only”, “control angle + control angle change rate”, “control angle + remaining distance”, “control angle + control angle change rate”. + Remaining distance ". By using the remaining distance from the tip of the wire to the discharge port of the laying head, highly sensitive control is performed where the remaining distance is large, so there is a situation where control continues even after the tip of the wire reaches the discharge port of the laying head. It is avoided more reliably.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. FIG. 4 is a block diagram of a control device according to an embodiment of the present invention, FIG. 5 is an explanatory diagram of membership functions used for fuzzy inference used for control amount calculation, and FIG. 6 is a fuzzy used for the fuzzy inference. FIG. 7 is a membership function diagram for explaining a specific procedure of the fuzzy inference.
[0021]
As shown in FIG. 4, the control device is used to control the rotational position of the laying head 3 provided on the downstream side of the finishing mill 2 of the production line for manufacturing the wire 1. As described above, the wire 1 is formed into a coil and discharged onto the conveyor 4 when passing through the laying head 3.
[0022]
The laying head 3 is rotationally driven by a motor 5, and the motor 5 is controlled and driven by a drive device 6 to control the rotational speed of the laying head 3. On the other hand, the finish rolling mill 2 is driven by a motor 7, and sensors 8 and 9 for detecting the passage of the tip of the wire 1 are disposed on the entry side and the exit side in order to catch the timing of control start. The motor 7 for driving the finishing mill 2 is provided with a pulse generator 10 for detecting the traveling speed Vn and the traveling distance of the wire 1, and the motor 5 for driving the laying head 3 includes A pulse generator 11 for detecting the rotational speed Vh of the head 3 and a pulse generator 12 for detecting the current position of the ejection port of the laying head 3 are attached.
[0023]
In the control, the traveling speed Vn of the wire 1 detected by the pulse generator 10 is given to the rotational position predicting means 13 from the time when the tip of the wire 1 is detected by the sensor 8. The rotational speed Vh of the laying head 3 detected by the pulse generator 11 is given to the rotational position predicting means 13. Then, the rotational position predicting means 13 predicts the rotational position of the discharge port when the leading end of the wire 1 reaches the discharge port of the laying head 3 by using the given information according to the following procedure. More specifically, the rotation amount R of the laying head 3 is calculated while the discharge port moves from the current position P to the predicted position Ry (see FIG. 2).
[0024]
First, the traveling distance of the wire 1 from the start of control is obtained by counting the number of output pulses of the pulse generator 10 attached to the motor 7 that drives the finishing mill 2, and this traveling distance is determined between the sensor 9 and the discharge port. The remaining distance L (m) from the tip end of the wire 1 to the discharge port is obtained by subtracting from the distance. Further, a lead ratio α (Vn / Vh), which is a speed ratio between the traveling speed Vn of the wire 1 and the rotational speed Vh of the laying head 3, is obtained. This lead rate α is normally 1 (other than during control) in order to keep the coil diameter of the wire 1 discharged from the discharge port constant.
[0025]
The time t required for the tip of the wire 1 to pass the remaining distance L (m) at a speed of Vn (m / s) is t = L / Vn (s). The rotation amount R of the laying head 3 during this period is R = t × Vh / πD = L / Vn / Vh / πD = L / πD × α (m), where D (m) is the diameter of the laying head 3. . The predicted position Ry of the discharge port when the tip of the wire 1 reaches the discharge port is P + R, where P is the current position of the discharge port (see FIG. 2).
[0026]
In parallel with the prediction of the rotation position of the discharge port, the output of the pulse generator 12 is input to the rotation position detection means 14 so that the current position P of the discharge port is detected. Then, the target position Po of the discharge port output from the rotational position setting means 15 for setting the target rotational position of the discharge port, the current position P of the discharge port, and the lay head 3 from the current position P to the predicted position Ry described above. , The control angle θ (= Po−P−R) of the laying head 3 necessary for making the predicted position Ry of the discharge port coincide with the target position Po is calculated and given to the control amount calculation means 16. It is done. Further, the change rate dθ / dt of the control angle θ and the remaining distance L are given to the control amount calculation means 16.
[0027]
The control amount calculation means 16 calculates the control amount of the rotational speed of the laying head 3 by fuzzy inference using the control angle θ, the rate of change dθ / dt of the control angle θ, and the remaining distance L. The calculation procedure is as follows.
[0028]
For the control angle θ, the change rate dθ / dt of the control angle θ, and the remaining distance L, a membership function as shown in FIG. 5 and a fuzzy rule as shown in FIG. 6 are set. The basic rule here is that the greater the input factor of the control angle θ, the rate of change dθ / dt of the control angle θ, and the remaining distance L, the greater the ratio of the control amount to the factor, that is, the gain. Is to increase. The numbers in the fuzzy rule shown in FIG. 6 correspond to the gain.
[0029]
In order to simplify the description, the calculation contents of fuzzy will be described with reference to FIG. 7 in the case of using the control angle θ and the change rate dθ / dt of the control angle θ as the fuzzy input factor. The height method was used for the calculation. Further, the horizontal axis of the diagram showing the membership function of the control angle θ is obtained by scaling the actual angle (°). The scaling factor is 0.02, and ± 1 corresponds to ± 200 °.
[0030]
When the control angle θ is 108 ° and the rate of change of the control angle θ is 0, the data of FIG. 7A or FIG. 7B is obtained by performing fuzzy calculation and defuzzification by the height method. The output Y at this time is Y = 0.16 from the following equation.

[0031]
The result of further scaling is used as a control amount for the rotational speed of the laying head 3. Then, a value obtained by adding the control amount to the reference speed output from the rotation speed setting means 17 for setting the reference value of the rotation speed of the laying head 3 is given to the drive device 6 of the motor 5 as an instruction speed.
[0032]
When the tip of the wire 1 is detected by the sensor 9, the tip position is corrected here and the control is continued. By starting the control from the sensor 8 provided on the entry side of the finishing mill 2, the control time is secured.
[0033]
FIG. 8 shows changes with time in the control output when the rotational position of the laying head is controlled in this way. As is clear from comparison with FIG. 3, in the case of the present invention, the discharge port is controlled to the target position in a shorter time than the conventional case using PI control, and the rotational speed of the laying head 3 returns to the reference value. As a result, the drop position accuracy at the tip of the wire is improved. Moreover, the deterioration of the coil shape of a wire rod front-end | tip part is avoided by suppressing the fluctuation | variation of the rotational speed of the laying head 3 after the front-end | tip of the wire rod 1 arrives at a discharge outlet.
[0034]
FIG. 9A is a chart showing variations in the drop position of the wire tip in the case of the present invention and in the conventional case using PI control. The present invention has higher drop position accuracy from low speed to high speed, and the effect is particularly remarkable in high speed rolling. FIG. 9B is a chart showing the rotational speed deviation of the laying head at the end of control when rolling is performed at a wire diameter of 5.5 mm and a speed of 60 m / s (when the tip of the wire reaches the discharge port). . According to the present invention, the rotational speed deviation of the laying head is reduced to about 1/5, and the coil shape at the tip of the wire is improved to a level that does not require maintenance.
[0035]
【The invention's effect】
As is apparent from the above description, the rotational position control device for the laying head according to the present invention calculates the control angle, the rate of change of the control angle, and the leading end of the laying head when calculating the control amount of the rotational speed of the laying head. Since one or more factors including at least the control angle of the remaining distance to the discharge port are used and the gain is increased as the factor is larger, the control time is shorter than in the conventional control with a constant gain. Even when the traveling speed is high, the control can be completed by the time when the tip of the wire reaches the discharge port of the laying head. Therefore, even when the traveling speed of the wire is high, the tip of the wire can be accurately dropped to a predetermined position. In addition, since the rotational speed of the laying head returns to the reference value by the time when the tip of the wire reaches the ejection port of the laying head, deterioration of the coil shape at the tip of the wire can be avoided.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a wire production line.
FIG. 2 is a schematic diagram showing a rotational position of a discharge head of a laying head.
FIG. 3 is a chart showing temporal changes in control output when the rotational position of a laying head is controlled using PI control.
FIG. 4 is a configuration diagram of a control device according to an embodiment of the present invention.
FIG. 5 is an explanatory diagram of a membership function used for fuzzy inference used for control amount calculation.
FIG. 6 is an explanatory diagram of fuzzy rules used for the fuzzy inference.
FIG. 7 is an explanatory diagram of a membership function for explaining a specific procedure of the fuzzy reasoning.
FIG. 8 is a chart showing a change with time in control output when the rotational position of the laying head is controlled using fuzzy control.
FIG. 9 is a chart showing the effects of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Wire rod 2 Finishing mill 3 Laying head 4 Conveyor 5, 7 Motor 6 Drive apparatus 8, 9 Tip sensor 10, 11, 12 Pulse generator 13 Rotation position prediction means 14 Rotation position detection means 15 Rotation position setting means 16 Control amount calculation means 17 Rotation speed setting means

Claims (2)

A means for rotationally driving the laying head that forms a coil by rotating the wire passing through the inside and discharging it from the discharge port, and at the point when the tip of the wire reaches the discharge port of the laying head by tracking the tip position of the wire Means for predicting the rotational position of the discharge port, means for detecting the current rotational position of the discharge port, and means for determining the control angle of the laying head necessary to match the predicted rotational position of the discharge port to the target position And calculating the control amount of the rotational speed of the laying head using at least one factor including at least the control angle among the control angle, the rate of change of the control angle, and the remaining distance from the tip of the wire to the discharge port of the laying head. with the means for increasing the higher the factor is larger gain (ratio of the control amount to the magnitude of the factor) when performing the calculation, Le at the calculated control amount Rotation position control apparatus for laying head, characterized in that and means for controlling the rotational speed of Nguheddo. One or more factors including the control angle are “control angle only”, “control angle + control angle change rate”, “control angle + residual distance” or “control angle + control angle change rate + remaining distance”. The rotational position control device of a laying head according to claim 1.

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