阅读说明：本技术 一种卷材边部自适应控制方法及系统 (Self-adaptive control method and system for edge of coiled material ) 是由 熊雯 邱鹏 张健民 丁茹 赵雪松 于 2021-06-30 设计创作，主要内容包括：本发明公开了一种卷材边部自适应控制方法及系统,利用侧导板以带卷边部位置基准值向内关闭,并且在其受到的实际带卷阻力值达到所述带卷边部位置基准值,改为控制侧导板的两边以带卷中心线移动。可见,本发明实施例以带卷为基准调整,依据自学习实现卷材边部的快速定位调节。故能够有效防止卷材跑偏的问题。另外,由于摒弃了强迫推挤卷材靠近轧制中心线的方式,而是利用调整侧导板的方式来防止卷材跑偏,能够有效防止卷材边受损,保证卷材的产品质量。(The invention discloses a self-adaptive control method and a self-adaptive control system for the edge part of a coiled material. Therefore, the embodiment of the invention takes the coil as a reference for adjustment, and realizes the quick positioning adjustment of the edge of the coiled material according to self-learning. Therefore, the problem of deviation of the coiled material can be effectively prevented. In addition, the mode of forcedly pushing the coiled material to be close to the rolling center line is abandoned, and the coiled material is prevented from deviating by adjusting the side guide plates, so that the edges of the coiled material can be effectively prevented from being damaged, and the product quality of the coiled material is ensured.)

1. A method for adaptive control of a web edge portion, the method comprising:

tracking and detecting the real-time length of the strip after the strip is rolled out of the finish rolling tail frame;

if the real-time length is larger than a preset length threshold value, calculating a tape roll edge position reference value, and controlling the side guide plate to close inwards according to the tape roll edge position reference value;

judging whether the actual tape roll resistance value of the side guide plate in the closing process reaches the tape roll edge part position reference value or not;

if so, controlling the two sides of the side guide plate to move along the central line of the coil;

measuring the distance from the side guide plate to the central line of the strip coil in the process that two sides of the side guide plate move along the central line of the strip coil, and judging whether the distance from the side guide plate to the central line of the strip coil meets a preset distance threshold value or not;

and if so, controlling the side guide plate to keep the current state.

2. The method of claim 1, wherein prior to tracking the real-time length of the test strip after it exits the finishing end stand, the method further comprises:

calculating the opening degree of the side guide plate before coiling by taking the central line of the equipment as a reference; wherein, the opening degree of side guide is:wherein, O_NS0、O_Ds0The distances of the operation measuring side and the transmission side of the side guide plate relative to the central line of the equipment are respectively measured; b is the width of the coiled material before coiling; beta is the opening correction coefficient of the side guide plate before the coiling.

3. The method of claim 1, wherein tracking the real-time length of the test strip after it exits the finishing end stand comprises:

by the formulaTracking and detecting the real-time length of the strip after the strip is rolled out of the finish rolling tail frame; wherein L represents the real-time length of the coil after it exits the finish rolling mill stand; v_tRepresenting the steel throwing speed of the final frame of finish rolling; t0 represents the finish rolling end stand steel throwing start time; ta denotes the moment when the coil reaches the coiler.

4. The method of claim 1, wherein calculating the tape spool edge position reference value comprises:

according to formula F_ref＝k×(ah²+bh+c)×k_t×k_y×k_mCalculating a reference value of the position of the edge of the strip coil; wherein, F_refIndicating a tape roll edge position reference value, KN; h is the thickness of the coiled material, mm; k is a correction coefficient; k is a radical of_tThe coil temperature correction coefficient; k is a radical of_yThe coil strength correction coefficient; k is a radical of_mSetting a correction coefficient for manual work; and a, b and c are coil thickness correction coefficients.

5. The method of claim 1 or 4, wherein said determining whether the actual coil resistance experienced by said side guides during closing reaches said coil edge position reference value comprises:

by the formula F_act＜F_ref+ epsilon judging whether the actual tape roll resistance value reaches the tape roll edge position reference value or not; wherein, F_actIs said actual coil drag value, F_refThe reference value of the position of the edge of the tape roll is shown, and epsilon represents a correction value.

6. The method of claim 1, wherein said calculating the distance of said side guides from the centerline of said tape roll comprises:

by the formula O_NS1＝O_DS1Calculating the distance from the side guide plate to the central line of the coil as X + 0.5; wherein O is_NS1、O_DS1After the edge searching is finished, the operating side and the transmission side of the side guide plate are respectively away from the central line of the tape roll; x is the calculated position of the tape change.

7. The method of claim 1, wherein after determining whether the distance of the side guides from the tape roll centerline satisfies a preset distance threshold, the method further comprises:

if not, the side guide plate controls the switching to pressure control, and the winding drum and the wrapper roller are controlled to align.

8. The method of any one of claims 2-7, wherein the method further comprises:

and self-learning the opening correction coefficient updating value of the side guide plate, and updating the opening correction coefficient of the side guide plate before coiling into the opening correction coefficient of the side guide plate at the next coiling by using the opening correction coefficient updating value.

9. The method of claim 8, wherein the self-learning of the aperture correction factor of the side guides comprises:

using the formula beta_new＝β+(β_act- β) x α self-learning an update value of an aperture correction factor of the side guide; wherein, beta_newUpdating the aperture correction factor of the side guide plate, wherein beta is the aperture correction factor of the side guide plate before coiling, and beta is the aperture correction factor of the side guide plate before coiling_actAlpha is the genetic susceptibility value for the actual correction factor.

10. A web edge adaptive control system, the system comprising:

the coiled material position detection module is used for tracking and detecting the real-time length of the strip after the strip is coiled out of the finish rolling tail stand;

the tape roll edge searching calculation module is used for calculating a tape roll edge part position reference value if the real-time length is larger than a preset length threshold value;

the side guide plate control module is used for controlling the side guide plates to close inwards according to the reference value of the position of the edge of the tape roll;

the judging module is used for judging whether the actual tape roll resistance value of the side guide plate in the closing process reaches the tape roll edge position reference value or not;

the side guide plate control module is also used for controlling the two sides of the side guide plate to move along the central line of the coil if the side guide plate control module is used for controlling the two sides of the side guide plate to move along the central line of the coil;

the calculation module is used for calculating the distance from the side guide plate to the central line of the strip coil in the process of measuring the movement of two sides of the side guide plate along the central line of the strip coil;

the judging module is specifically used for judging whether the distance from the side guide plate to the central line of the tape roll meets a preset distance threshold value;

and the control module is used for controlling the side guide plate to keep the current state if the current state is the current state.

Technical Field

The application relates to the technical field of metallurgy, in particular to a self-adaptive control method and system for the edge of a coiled material.

Background

The coiling process of the metal material is generally the final process after the controlled rolling and controlled cooling process of the material and before the material is delivered for use. Therefore, the control precision is an important influence factor of the finished product quality and the production capacity of a production line. The front side guide plate of the coiling equipment is an important component of the coiling area equipment and is positioned behind the laminar flow cooling device, in front of the pinch roll and above the output roller table. The main function of the device is to clamp the coil to align with the central line of rolling, guide the coil to enter the coiler smoothly and provide certain back tension. The functional input and the precision maintenance of the side guides have a direct influence on the coil quality of the hot-rolled sheet coil, and poor working conditions thereof may lead to coil quality problems such as turriform, nesting, edge emergence, coil layer dislocation, edge breakage and the like.

Meanwhile, the coil material deviation has great randomness due to a plurality of factors influencing the central line of the coil material, such as the shape of a finish rolling plate, the uniformity of laminar cooling and the like. Therefore, how to prevent the coiled material from deviating is a problem which needs to be solved urgently.

Disclosure of Invention

The invention provides a self-adaptive control method and a self-adaptive control system for edges of coiled materials, which aim to solve or partially solve the technical problem of coiled material deviation.

In order to solve the technical problem, the invention provides a self-adaptive control method for the edge of a coiled material, which comprises the following steps:

tracking and detecting the real-time length of the strip after the strip is rolled out of the finish rolling tail frame;

if the real-time length is larger than a preset length threshold value, calculating a tape roll edge position reference value, and controlling the side guide plate to close inwards according to the tape roll edge position reference value;

judging whether the actual tape roll resistance value of the side guide plate in the closing process reaches the tape roll edge part position reference value or not;

if so, controlling the two sides of the side guide plate to move along the central line of the coil;

measuring the distance from the side guide plate to the central line of the strip coil in the process that two sides of the side guide plate move along the central line of the strip coil, and judging whether the distance from the side guide plate to the central line of the strip coil meets a preset distance threshold value or not;

and if so, controlling the side guide plate to keep the current state.

Preferably, before tracking the real-time length of the test strip after being unwound from the finish end mill stand, the method further comprises:

calculating the opening degree of the side guide plate before coiling by taking the central line of the equipment as a reference; wherein, the opening degree of side guide is:wherein, O_NS0、O_DS0The distances of the operation measuring side and the transmission side of the side guide plate relative to the central line of the equipment are respectively measured; b is the width of the coiled material before coiling; beta is the aperture correction factor of the side guide plate before coiling.

Preferably, the tracking and detecting of the real-time length of the strip after being rolled out of the finish rolling final stand specifically includes:

by the formulaTracking and detecting the real-time length of the strip after the strip is rolled out of the finish rolling tail frame; wherein L represents the real-time length of the coil after it exits the finish rolling mill stand; v_tRepresenting the steel throwing speed of the final frame of finish rolling; t0 represents the finish rolling end stand steel throwing start time; ta denotes the moment when the coil reaches the coiler.

Preferably, the calculating the tape roll edge position reference value specifically includes:

according to formula F_ref＝k×(ah²+bh+c)×k_t×k_y×k_mCalculating a reference value of the position of the edge of the strip coil; wherein, F_refIndicating a tape roll edge position reference value, KN; h is the thickness of the coiled material, mm; k is a correction coefficient; k is a radical of_tThe coil temperature correction coefficient; k is a radical of_yThe coil strength correction coefficient; k is a radical of_mSetting a correction coefficient for manual work; and a, b and c are coil thickness correction coefficients.

Preferably, the judging whether the actual tape roll resistance value received by the side guide plate in the closing process reaches the tape roll edge position reference value specifically includes:

by the formula F_act＜F_ref+ ε determining said realityWhether the strip coil resistance value reaches the strip coil edge part position reference value or not; wherein, F_actIs said actual coil drag value, F_refThe reference value of the position of the edge of the tape roll is shown, and epsilon represents a correction value.

Preferably, the calculating the distance from the side guide to the central line of the tape roll specifically includes:

by the formula O_NS1＝O_DS1Calculating the distance from the side guide plate to the central line of the coil as X + 0.5; wherein O is_NS1、O_DS1After the edge searching is finished, the operating side and the transmission side of the side guide plate are respectively away from the central line of the tape roll; x is the calculated position of the tape change.

Preferably, after determining whether the distance from the side guide to the central line of the tape roll meets a preset distance threshold, the method further includes:

if not, the side guide plate controls the switching to pressure control, and the winding drum and the wrapper roller are controlled to align.

Preferably, the method further comprises:

and self-learning the opening correction coefficient updating value of the side guide plate, and updating the opening correction coefficient of the side guide plate before coiling into the opening correction coefficient of the side guide plate at the next coiling by using the opening correction coefficient updating value.

Preferably, the self-learning of the correction coefficient of the opening of the side guide plate specifically includes:

using the formula beta_new＝β+(β_act- β) x α self-learning an update value of an aperture correction factor of the side guide; wherein, beta_newUpdating the aperture correction factor of the side guide plate, wherein beta is the aperture correction factor of the side guide plate before coiling, and beta is the aperture correction factor of the side guide plate before coiling_actAlpha is the genetic susceptibility value for the actual correction factor.

The invention also discloses a self-adaptive control system for the edge of the coiled material, which comprises the following steps:

the coiled material position detection module is used for tracking and detecting the real-time length of the strip after the strip is coiled out of the finish rolling tail stand;

the tape roll edge searching calculation module is used for calculating a tape roll edge part position reference value if the real-time length is larger than a preset length threshold value;

the side guide plate control module is used for controlling the side guide plates to close inwards according to the reference value of the position of the edge of the tape roll;

the judging module is used for judging whether the actual tape roll resistance value of the side guide plate in the closing process reaches the tape roll edge position reference value or not;

the side guide plate control module is also used for controlling the two sides of the side guide plate to move along the central line of the coil if the side guide plate control module is used for controlling the two sides of the side guide plate to move along the central line of the coil;

the calculation module is used for calculating the distance from the side guide plate to the central line of the strip coil in the process of measuring the movement of two sides of the side guide plate along the central line of the strip coil;

the judging module is specifically used for judging whether the distance from the side guide plate to the central line of the tape roll meets a preset distance threshold value;

and the control module is used for controlling the side guide plate to keep the current state if the current state is the current state.

Through one or more technical schemes of the invention, the invention has the following beneficial effects or advantages:

in order to solve the problem of deviation of the coiled material, the invention discloses a self-adaptive control method and a self-adaptive control system for the edge of the coiled material. Therefore, the embodiment of the invention takes the coil as a reference for adjustment, and realizes the quick positioning adjustment of the edge of the coiled material according to self-learning. Therefore, the problem of deviation of the coiled material can be effectively prevented. In addition, the mode of forcedly pushing the coiled material to be close to the rolling center line is abandoned, and the coiled material is prevented from deviating by adjusting the side guide plates, so that the edges of the coiled material can be effectively prevented from being damaged, and the product quality of the coiled material is ensured.

The foregoing description is only an overview of the technical solutions of the present invention, and the embodiments of the present invention are described below in order to make the technical means of the present invention more clearly understood and to make the above and other objects, features, and advantages of the present invention more clearly understandable.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to refer to like parts throughout the drawings. In the drawings:

FIG. 1 illustrates a flow chart of a method for adaptive control of web edge margins according to one embodiment of the present invention;

FIG. 2 shows a schematic structural view of a coiler according to one embodiment of the present invention;

FIG. 3 is a schematic diagram of a web edge adaptive control system according to one embodiment of the present invention.

Detailed Description

In order to make the present application more clearly understood by those skilled in the art to which the present application pertains, the following detailed description of the present application is made with reference to the accompanying drawings by way of specific embodiments.

In order to solve the problem of deviation of the coiled material, the applicant discloses a coiled material edge self-adaptive control method, wherein side guide plates are utilized to close inwards according to a coil edge position reference value, and when the actual coil resistance value of the side guide plates reaches the coil edge position reference value, the two sides of the side guide plates are controlled to move along the coil central line. Therefore, the embodiment of the invention takes the coil as a reference for adjustment, and realizes the quick positioning adjustment of the edge of the coiled material according to self-learning. Therefore, the problem of deviation of the coiled material can be effectively prevented. In addition, the mode of forcedly pushing the coiled material to be close to the rolling center line is abandoned, and the coiled material is prevented from deviating by adjusting the side guide plates, so that the edges of the coiled material can be effectively prevented from being damaged, and the product quality of the coiled material is ensured.

Referring now to fig. 1, a method of an embodiment of the present invention includes the steps of:

and step 101, tracking and detecting the real-time length of the strip after the strip is rolled out of the final rolling mill frame.

The schematic structure of the coiler of the present embodiment is shown in fig. 2. The device comprises an equipment central line 1, a coil central line 2, a coiling front roller bed 3, a side guide plate hydraulic system 4, a hydraulic balance system 5 and a side guide plate 6.

And (3) initializing a program before coiling, acquiring and quantizing data, and finishing the initial setting of process design parameters. The opening degree of the side guides needs to be adjusted in advance thereafter. In the process, the opening degree of the side guide plate before coiling is calculated by taking the central line of the equipment as a reference, and then the placing position of the side guide plate is adjusted by the opening degree, so that the position of the side guide plate of the coiling machine is accurate, and a good foundation is laid for preventing coiled materials from deviating.

In particular, using formulasAnd calculating the opening degree of the side guide plate before the coiling. Wherein, O_NS0、O_DS0The distances of the operation measuring side and the transmission side of the side guide plate relative to the central line of the equipment are respectively measured; b is the width of the coiled material before the coiling; beta is the opening correction coefficient of the side guide plate before the coiling.

After the adjustment is completed, the coiling operation can be carried out.

In the coiling process, the coiled strip is coiled after coming out of the final stand of the finishing mill, so that the real-time length of the coiled strip after coming out of the final stand of the finishing mill is tracked and detected.

In particular, by means of formulaeTracking and detecting the real-time length of the strip after the strip is rolled out of the finish rolling tail frame; wherein L represents the real-time length of the coil after it exits the finish rolling mill stand; v_tRepresenting the steel throwing speed of the final frame of finish rolling; t0 represents the finish rolling end stand steel throwing start time; ta denotes the moment when the coil reaches the coiler.

And 102, if the real-time length is larger than a preset length threshold value, calculating a tape roll edge position reference value, and controlling the side guide plate to close inwards according to the tape roll edge position reference value.

Wherein the preset length threshold refers to the relative distance between the finishing mill and the front end of the coiling side guide plate. If the real-time length is larger than the preset length threshold value, the coiled material reaches the coiling machine and needs to be coiled, the side guide plates are inwards closed according to the coil edge position reference value to search for the edge of the coiled material, and therefore the coiling process is conveniently executed.

In the process of calculating the reference value of the edge position of the coil, the formula F is used_ref＝k×(ah²+bh+c)×k_t×k_y×k_mAnd calculating the reference value of the position of the edge of the tape roll. Wherein, F_refIndicating a tape roll edge position reference value, KN; h is the thickness of the coiled material, mm; k is a correction coefficient (0.3-0.6); k is a radical of_tThe coil temperature correction coefficient; k is a radical of_yThe coil strength correction coefficient is (0.95-1.05); k is a radical of_mSetting correction coefficient (0.75-1.25) for manual operation; and a, b and c are coil thickness correction coefficients.

The main purpose of the reference value of the coil edge position is to restrain lateral position deviation of the coil as much as possible without damaging the coil edge and without affecting forward movement of the coil and biting of the tension roller. Therefore, the side guide plates are closed according to the direction to find the edge of the coiled material, so that the lateral position deviation of the coiled material can be avoided as much as possible, and the coiled material is prevented from deviating.

And 103, judging whether the actual tape roll resistance value of the side guide plate in the closing process reaches the tape roll edge position reference value or not.

Specifically, the tape roll edge position reference value, that is, the side guide edge pressure reference value. The in-process that the curb plate inwards closed, owing to receive the resistance of coiled material, the actual coil of strip resistance value that the pressure sensor detection curb plate received through curb plate hydraulic system closed the in-process to whether further judge it reaches curb plate limit pressure benchmark value, if reach curb plate limit pressure benchmark value, think the step completion that the curb plate looked for coiled material limit portion, the curb plate is corresponding with coiled material limit portion this moment, can effectively prevent the coiled material off tracking.

Furthermore, in the judging process, the actual coil resistance value and the coil edge position reference value can be directly judged. In order to make the judgment more accurately, a correction value may be set for correction. By the formula F_act＜F_refAnd + epsilon judging whether the actual tape roll resistance value reaches the tape roll edge part position reference value or not. Wherein, F_actIs said actual coil drag value, F_refThe reference value of the position of the edge of the tape roll is shown, and epsilon represents a correction value.

And after the edge seek is completed, step 104 is performed.

And 104, if so, controlling the two sides of the side guide plate to move along the central line of the coil.

The side guide plate can move in the coiling process, so that two sides of the side guide plate are controlled to move along the central line of the coil, and the coil can be effectively prevented from deviating.

And 105, measuring the distance from the side guide plate to the central line of the strip coil in the process of moving two sides of the side guide plate along the central line of the strip coil, and judging whether the distance from the side guide plate to the central line of the strip coil meets a preset distance threshold value.

In a specific implementation, the formula O is used_NS1＝O_DS1Calculating the distance from the side guide plate to the central line of the coil as X + 0.5; wherein O is_NS1、O_DS1After the edge searching is finished, the operating side and the transmission side of the side guide plate are respectively away from the central line of the tape roll; x is the calculated position of the tape change.

The preset distance threshold may be determined according to practical situations, and is not limited herein. If the preset distance threshold is met, it indicates that the positions of the side guides and the coil are suitable, so step 106 is executed, and if yes, the side guides are controlled to keep the current state.

If not, namely: if the preset distance threshold value is not met, the position of the side guide plate and the coiled material is not matched, the coiled material needs to be controlled, the pressure control is switched into from the side guide plate control, and in addition, the coiling drum and the coiling assisting roller are controlled to be aligned to prevent the coiled material from deviating.

As an optional embodiment, in this embodiment, on the basis of any of the above embodiments, an updated value of the aperture correction coefficient of the side guide plate is self-learned, and the aperture correction coefficient of the side guide plate before the current winding is updated to the aperture correction coefficient of the side guide plate at the next winding by using the updated value of the aperture correction coefficient.

Further, using the formula β_new＝β+(β_act- β) x α self-learning an update value of an aperture correction factor of the side guide; wherein, beta_newUpdating the aperture correction factor of the side guide plate, wherein beta is the aperture correction factor of the side guide plate before coiling, and beta is the aperture correction factor of the side guide plate before coiling_actAlpha is the genetic susceptibility value for the actual correction factor. By the original genetic coefficient beta_oldCalculating the coiling temperature variation delta T in the range of (-delta sigma O, + delta sigma O) according to a certain step length as a reference point, and then the genetic sensitivity value is as follows:

further, in the updating process, the opening correction coefficient of the side guide plate before the current coiling is updated according to the weight η and the opening correction coefficient update value, so that the opening correction coefficient of the side guide plate at the next coiling is obtained.

Therefore, the embodiment can perform the adaptive learning of the opening correction coefficient of the side guide plate, and can update the opening correction coefficient of the side guide plate in real time so as to be more suitable for the coiling of the coiling machine.

Based on the same inventive concept, the embodiment of the invention also discloses a self-adaptive control system for the edge of the coiled material, which can realize the automatic adjustment of the control system and quickly feed back the adjustment result according to self-learning. The device has simple structure, stable operation, safety and reliability. Referring to fig. 3, the system includes:

a coiled material position detection module 31 for tracking and detecting the real-time length of the strip after being rolled out of the finish rolling final stand;

the tape edge searching calculation module 32 is configured to calculate a tape edge position reference value if the real-time length is greater than a preset length threshold;

a side guide plate control module 33 for controlling the side guide plates to close inwards according to the reference value of the tape roll edge position;

a judging module 34, configured to judge whether an actual tape roll resistance value applied to the side guide during closing reaches a tape roll edge position reference value;

the side guide plate control module 33 is further configured to, if yes, control two sides of the side guide plate to move along a central line of the tape roll;

the calculation module 35 is used for calculating the distance from the side guide plate to the central line of the coil in the process of measuring the movement of two sides of the side guide plate along the central line of the coil;

the judging module 34 is specifically configured to judge whether a distance from the side guide to the central line of the tape roll meets a preset distance threshold;

and the control module 36 is configured to control the side guide to keep the current state if the current state is the current state.

In a specific implementation, the system comprises: a post-calculation and self-adaptation module, a coil central positioning control module, a winding drum system alignment control module, a pinch roll control module, a side guide plate control module 33, a coil edge-searching calculation module 32, a coil position detection module 31, a coil central line offset compensation calculation module and a wrapper roll system alignment control module.

The coil central positioning control module is connected with the post-calculation and self-adaptation module, the coil searching and calculating module, the winding drum system alignment control module, the pinch roll control module and the side guide plate control module 33, so that data exchange among the coil central positioning control module, the post-calculation and self-adaptation module, the coil searching and calculating module, the winding drum system alignment control module, the pinch roll control module and the side guide plate control module 33 is realized.

Furthermore, in the control flow of the system, after program initialization and data acquisition and quantification processing, the coil center positioning control module is used for positioning and controlling the coil center. The coil position detection module 31 is started to track the real-time length of the strip after it has been unwound from the final finish rolling stand. Thereafter, the side guide control module 33, the pinch roller control module, and the coil edge-finding calculation module 32 are started. The pinch roll control module is used for controlling the pinch roll to work. A tape edge-finding calculation module 32 for calculating a tape edge-position reference value, and a side guide control module 33 for controlling the side guides to close inward according to the tape edge-position reference value. When the edge searching calculation is completed, the position of the side guide plate is moved by taking the center of the tape roll as a reference. And after the side guide plate control is switched to pressure control, the quality of the edge and the tail of the coiled material is ensured. And starting the tape coil central line offset compensation calculation module to perform offset compensation. And the winding drum system alignment control module and the wrapper roller system alignment control module are started to control the winding drum and the wrapper roller to align. Through the interaction of the modules, the self-adaption and the quick adjustment of the edge of the coiled material are realized.

While the preferred embodiments of the present application have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all alterations and modifications as fall within the scope of the application.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present application without departing from the spirit and scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations as well.