阅读说明：本技术 一种视觉传感的电磁调控轧辊辊型监测装置及其方法 (Visual sensing electromagnetic regulation and control roller shape monitoring device and method ) 是由 王海军 杨庭松 刘家杨 许志强 杜凤山 于 2020-11-17 设计创作，主要内容包括：本发明涉及一种视觉传感的电磁调控轧辊辊型监测装置及其方法,所述装置包括电磁调控轧辊、感应线圈温度传感器、轧辊温度传感器、热成像仪、电磁棒、信号滑环和信号采集分析系统；电磁棒内置于电磁调控轧辊的轴心处,轧辊温度传感器均布在与电磁棒感应加热区对应的轧辊内孔壁上,感应线圈温度传感器均布在电磁棒感应线圈的上下两侧,信号滑环设置在电磁调控轧辊的一端,感应线圈温度传感器和轧辊温度传感器通过信号滑环连接至信号采集分析系统,所述热成像仪设置在电磁调控轧辊的外侧。本发明具有在线、非接触测量辊型的动态监测能力,可针对电磁调控轧辊的辊型过程变化特性进行实时的辊型检测,不但响应速率高,而且对轧制过程无影响。(The invention relates to a monitoring device and a method for a roller shape of an electromagnetic regulation and control roller by visual sensing, wherein the device comprises the electromagnetic regulation and control roller, an induction coil temperature sensor, a roller temperature sensor, a thermal imager, an electromagnetic rod, a signal slip ring and a signal acquisition and analysis system; the electromagnetic control roller is arranged in the electromagnetic rod at the axis center, the roller temperature sensors are uniformly distributed on the inner hole wall of the roller corresponding to the induction heating area of the electromagnetic rod, the induction coil temperature sensors are uniformly distributed on the upper side and the lower side of an induction coil of the electromagnetic rod, the signal slip ring is arranged at one end of the electromagnetic control roller, the induction coil temperature sensors and the roller temperature sensors are connected to a signal acquisition and analysis system through the signal slip ring, and the thermal imager is arranged outside the electromagnetic control roller. The invention has the dynamic monitoring capability of measuring the roll shape on line and in a non-contact way, can carry out real-time roll shape detection aiming at the change characteristic of the roll shape process of the electromagnetic control roll, has high response rate and has no influence on the rolling process.)

1. The utility model provides a visual sense's electromagnetic control roll type monitoring devices which characterized in that: the device comprises an electromagnetic regulation and control roller, an induction coil temperature sensor, a roller temperature sensor, a thermal imager, an electromagnetic rod, a signal slip ring and a signal acquisition and analysis system; the electromagnetic bar is arranged in the axis of the electromagnetic control roller, the roller temperature sensors are uniformly distributed on the upper side and the lower side of the inner hole wall of the roller corresponding to the induction heating area of the electromagnetic bar, the induction coil temperature sensors are uniformly distributed on the upper side and the lower side of the induction coil of the electromagnetic bar, the induction coil temperature sensors are correspondingly distributed on the inner side of the roller temperature sensors, and the number of the roller temperature sensors and the number of the induction coil temperature sensors are equal to the number of the induction heating areas on the electromagnetic bar and are used for detecting the temperature of the inner wall of the roller at the corresponding part; the signal slip ring is arranged at one end of the electromagnetic control roller, the induction coil temperature sensor and the roller temperature sensor are respectively connected to a signal acquisition and analysis system through the signal slip ring, and the connection mode is a shunt multi-channel connection; the thermal imager is arranged on the outer side of the electromagnetic control roller, an image collecting area of the thermal imager can project towards the electromagnetic control roller, and the center of the projection area is located at the center of the axis of the roller body of the electromagnetic control roller.

2. The visually-sensed electromagnetically-modulated roll profile monitoring apparatus of claim 1, wherein: the axial hole of circumference equipartition is provided with in the terminal surface axle center department of electromagnetic rod, the degree of depth in axial hole equals the length that electromagnetic rod terminal surface put to its induction heating district central point, just the quantity of axial hole is twice of electromagnetic rod induction heating district quantity, induction coil temperature sensor corresponds and sets up inside the axial hole.

3. The visually-sensed electromagnetically-regulated roll profile monitoring device as claimed in claim 1 or 2, wherein: and annular grooves which are arranged at certain intervals and correspond to the roller temperature sensors are formed in the circumferential surface of the electromagnetic rod.

4. The method of claim 3 for monitoring roll profile with a vision-sensing electromagnetically regulated roll profile monitoring device, wherein the method comprises the steps of: the method comprises the following steps:

s1, connecting the electromagnetic control roller to an induction heating variable frequency power supply, connecting the thermal imager to an image processing computer, connecting the induction heating variable frequency power supply to an upper computer PLC, and respectively connecting the upper computer PLC, the image processing computer and the signal acquisition and analysis system to an electromagnetic control computer; the electromagnetic adjusting and controlling computer reads the temperature signal TDi of the induction coil, the internal temperature TRi of the roller and the section temperature f (xi) of the roller surface i at the same time interval;

s2, inputting a target roll shape f (x) into an electromagnetic regulation computer, equally dividing the target roll shape into i sections, and inputting structural parameters of the electromagnetic regulation roll, including the diameter Dr of the electromagnetic regulation roll, the length L of a roll body of the electromagnetic regulation roll, the diameter Dd of an electromagnetic rod, the number i of induction heating sections of the electromagnetic rod, the length Li of each induction heating section of the electromagnetic rod, the number k of contact zones and the length Lk of each contact zone of the electromagnetic rod;

s3, inputting preset electromagnetic parameters of a target roller shape, wherein the preset electromagnetic parameters comprise current density Ji, frequency fi and roller shape regulation time ti of each induction heating area;

s4, initializing the system before starting, and initializing a thermal imager, a roller temperature sensor and an induction coil temperature sensor;

s5: acquiring an induction coil temperature signal TDi and a roller internal temperature TRi through a signal acquisition and analysis system, and matching the induction coil temperature signal TDi and the roller internal temperature TRi to parameter sets of each section of the electromagnetic rod;

s6, acquiring a roller surface temperature distribution image through a thermal imager, and performing gray level processing on a roller body temperature field image through an image processing computer based on a machine vision technology to acquire a gray level matrix g (n, m);

s7, dividing the gray matrix into k sections, wherein the length of each section is equal to the length of an electromagnetic rod contact area in the electromagnetic control roller of the section plus the average value of induction heating areas on two sides of the length of the contact area, namely lk + (li + li + 1)/2;

s8, matching the maximum gray value pmax with the thermal imager feedback global maximum temperature Tmax, matching the minimum gray value pmin with the thermal imager feedback global minimum temperature Tmin, and then obtaining the temperature range [ Tmin, Tmax ] corresponding to the gray range [ pmin, pmax ].

S9, obtaining a gray-scale contour fj (n, m) by the gray-scale matrix g (n, m), judging the crossing condition of the gray-scale contour fj (n, m) and the gray-scale section divided in the step S7 by the system, and obtaining the temperature distribution condition of the crossing position according to the gray-scale-temperature mapping relation obtained in the step S8;

s10, taking the induction coil temperature signal TDi and the roll internal temperature TRi acquired in the step S5 as electromagnetic regulation roll internal temperature data, taking the roll surface highest and lowest temperature ranges [ Tmin, Tmax ] acquired in the step S8 as electromagnetic regulation roll surface temperature data, taking all the parameters input in the step S2 as electromagnetic regulation roll regulation initial parameters, addressing data in an existing electromagnetic regulation roll temperature field-roll shape database in the system, taking the data with high matching degree as the reference of the current measurement, outputting the matched roll shape data, and further acquiring a real-time roll shape.

5. The method of claim 4, wherein: and a signal acquisition module and a signal conversion module are arranged in the induction heating variable frequency power supply.

Technical Field

The invention relates to the technical field of steel rolling equipment in the metallurgical industry, in particular to a visual sensing monitoring device and method for the shape of an electromagnetic control roller.

Background

The common product quality problem in the production of plate and strip steel is the plate shape problem, and because the roll gap size is not transversely uniform in the rolling process, the extension and rolling thickness difference of different sections of a plate strip is induced, and finally the plate shape defect is caused. With the promotion of the market demand of plate and strip steel products, the further expansion of the application field of plate and strip steel and the product types, the plate shape requirement of the plate and strip steel becomes stricter. Under the background, roll shape flexible adjusting technologies such as a roll shape electromagnetic adjusting and controlling technology, a DSE series technology, a VC series technology and the like are successively proposed, and the roll shape adjusting and controlling becomes a research hotspot of current plate shape control. In the prior art, a roller capable of flexibly adjusting a roller profile curve (CN102527727A) and a segmented flexible roller convexity adjusting roller (CN108372204A) are both roller type electromagnetic adjusting rollers, an electrothermal expansion rod in the roller is used as a driving element, the online adjustment and control of the flexible roller profile are realized by means of an electromagnetic induction heating principle, and the roller type electromagnetic adjusting and controlling roller has the characteristics of strong adjusting and controlling capability and high roller rigidity.

At present, a sensor is arranged on the surface of a roller, and the sensor is used for identifying radial displacement and generating an electric signal to monitor the bulging amount of the roller. Meanwhile, a single temperature sensor is arranged in the roller and used for monitoring the temperature of the central position of the induction heating area of the electromagnetic rod, but the measurement of the mode can only realize the measurement of the off-line roller shape regulation and control of the roller, the roller is a rotating body in the rolling working condition, the rotating action of the rotating body destroys the measurement winding, and the roller surface in the rolling working condition rotates for a period to be contacted with a rolled piece to form rolling, and if the sensor is positioned in a roller gap, the sensor is destroyed. Therefore, this method is not suitable for on-line measurement of roll profile in rolling conditions. Besides the method, a method for performing roller shape sliding measurement on an auxiliary rail by using a pressure gauge, a displacement gauge and the like is available, but the measurement efficiency and the measurement accuracy are low, and the method is difficult to adapt to the roller shape regulation and control requirement in rolling. Therefore, a roller type monitoring device with on-line monitoring and non-contact measurement is urgently needed.

Disclosure of Invention

In view of the above problems, the present invention is to provide a visually-sensed electromagnetically-controlled roll profile monitoring apparatus and method with roll profile monitoring capability, non-contact monitoring capability, fast response, feedback adjustment capability, and visual sensing capability.

The technical scheme adopted by the invention is as follows:

the invention provides a visual sensing electromagnetic regulation and control roller shape monitoring device, which comprises an electromagnetic regulation and control roller, an induction coil temperature sensor, a roller temperature sensor, a thermal imager, an electromagnetic rod, a signal slip ring and a signal acquisition and analysis system, wherein the electromagnetic regulation and control roller is arranged on the roller shape monitoring device; the electromagnetic bar is arranged in the axis of the electromagnetic control roller, the roller temperature sensors are uniformly distributed on the upper side and the lower side of the inner hole wall of the roller corresponding to the induction heating area of the electromagnetic bar, the induction coil temperature sensors are uniformly distributed on the upper side and the lower side of the induction coil of the electromagnetic bar, the induction coil temperature sensors are correspondingly distributed on the inner side of the roller temperature sensors, and the number of the roller temperature sensors and the number of the induction coil temperature sensors are equal to the number of the induction heating areas on the electromagnetic bar and are used for detecting the temperature of the inner wall of the roller at the corresponding part; the signal slip ring is arranged at one end of the electromagnetic control roller, the induction coil temperature sensor and the roller temperature sensor are respectively connected to a signal acquisition and analysis system through the signal slip ring, and the connection mode is a shunt multi-channel connection; the thermal imager is arranged on the outer side of the electromagnetic control roller, an image collecting area of the thermal imager can project towards the electromagnetic control roller, and the center of the projection area is located at the center of the axis of the roller body of the electromagnetic control roller.

Further, the terminal surface axle center department of electromagnetism stick is provided with the axial hole of circumference equipartition, the degree of depth in axial hole equals the length that electromagnetism stick terminal surface put to its induction heating district central point, just the quantity in axial hole is twice of electromagnetism stick induction heating district quantity, induction coil temperature sensor corresponds and sets up inside the axial hole.

Furthermore, the circumferential surface of the electromagnetic rod is provided with annular grooves which are spaced at a certain distance and correspond to the roller temperature sensor.

A visual sensing monitoring method for the roller shape of an electromagnetic control roller is characterized by comprising the following steps: the method comprises the following steps:

s1, connecting the electromagnetic control roller to an induction heating variable frequency power supply, connecting the thermal imager to an image processing computer, connecting the induction heating variable frequency power supply to an upper computer PLC, and respectively connecting the upper computer PLC, the image processing computer and the signal acquisition and analysis system to an electromagnetic control computer; the electromagnetic adjusting and controlling computer reads the temperature signal TDi of the induction coil, the internal temperature TRi of the roller and the section temperature f (xi) of the roller surface i at the same time interval;

s2, inputting a target roll shape f (x) into an electromagnetic regulation computer, equally dividing the target roll shape into i sections, and inputting structural parameters of the electromagnetic regulation roll, including the diameter Dr of the electromagnetic regulation roll, the length L of a roll body of the electromagnetic regulation roll, the diameter Dd of an electromagnetic rod, the number i of induction heating sections of the electromagnetic rod, the length Li of each induction heating section of the electromagnetic rod, the number k of contact zones and the length Lk of each contact zone of the electromagnetic rod;

s3, inputting preset electromagnetic parameters of a target roller shape, wherein the preset electromagnetic parameters comprise current density Ji, frequency fi and roller shape regulation time ti of each induction heating area;

s4, initializing the system before starting, and initializing a thermal imager, a roller temperature sensor and an induction coil temperature sensor;

s5: acquiring an induction coil temperature signal TDi and a roller internal temperature TRi through a signal acquisition and analysis system, and matching the induction coil temperature signal TDi and the roller internal temperature TRi to parameter sets of each section of the electromagnetic rod;

s6, acquiring a roller surface temperature distribution image through a thermal imager, and performing gray level processing on a roller body temperature field image through an image processing computer based on a machine vision technology to acquire a gray level matrix g (n, m);

s7, dividing the gray matrix into k sections, wherein the length of each section is equal to the length of an electromagnetic rod contact area in the electromagnetic control roller of the section plus the average value of induction heating areas on two sides of the length of the contact area, namely lk + (li + li + 1)/2;

s8, matching the maximum gray value pmax with the thermal imager feedback global maximum temperature Tmax, matching the minimum gray value pmin with the thermal imager feedback global minimum temperature Tmin, and then obtaining the temperature range [ Tmin, Tmax ] corresponding to the gray range [ pmin, pmax ].

S9, obtaining a gray-scale contour fj (n, m) by the gray-scale matrix g (n, m), judging the crossing condition of the gray-scale contour fj (n, m) and the gray-scale section divided in the step S7 by the system, and obtaining the temperature distribution condition of the crossing position according to the gray-scale-temperature mapping relation obtained in the step S8;

s10, taking the induction coil temperature signal TDi and the roll internal temperature TRi acquired in the step S5 as electromagnetic regulation roll internal temperature data, taking the roll surface highest and lowest temperature ranges [ Tmin, Tmax ] acquired in the step S8 as electromagnetic regulation roll surface temperature data, taking all the parameters input in the step S2 as electromagnetic regulation roll regulation initial parameters, addressing data in an existing electromagnetic regulation roll temperature field-roll shape database in the system, taking the data with high matching degree as the reference of the current measurement, outputting the matched roll shape data, and further acquiring a real-time roll shape.

Furthermore, a signal acquisition module and a signal conversion module are arranged in the induction heating variable frequency power supply.

Compared with the prior art, the invention has the following beneficial effects:

compared with a micrometer measurement mode, the roller profile monitoring device has the roller profile dynamic monitoring capability, can perform real-time roller profile detection aiming at the roller profile process change characteristic of the electromagnetic regulation and control roller, and solves the problem that the micrometer measurement mode has no dynamic measurement capability;

compared with the existing electromagnetic regulation and control roller shape measuring method, the method has the online and non-contact measuring capability, strain gauges do not need to be distributed on the surface of the roller, the roller shape is mapped only by relying on information such as induction coil temperature points, roller internal temperature points, roller surface temperature fields, roller shape electromagnetic regulation and control parameters and the like, the response rate is high, and the method has no influence on rolling.

Drawings

FIG. 1 is a schematic overall structure diagram of an embodiment of a visual sensing electromagnetic roll profile monitoring device for a rolling mill roll according to the present invention;

FIG. 2 is a schematic view of the internal structure of the electromagnetic controlled roll of FIG. 1;

FIG. 3 is a schematic diagram of the structure of the electromagnetic rod of FIG. 2;

fig. 4 is a schematic flow chart of roll profile monitoring according to the present invention.

Wherein, the reference numbers:

Detailed Description

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

It should be noted that in the description of the present invention, the terms "upper", "lower", "top", "bottom", "one side", "the other side", "left", "right", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of describing the present invention and simplifying the description, but do not mean that a device or an element must have a specific orientation, be configured and operated in a specific orientation.

Referring to fig. 1 to 3, a specific structure of an embodiment of a visual sensing electromagnetic control roll shape monitoring device according to the present invention is shown. The device comprises an electromagnetic regulation and control roller 1, an induction coil temperature sensor 2, a roller temperature sensor 3, a thermal imager 4, an electromagnetic rod 5, a signal slip ring 6 and a signal acquisition and analysis system 7; the electromagnetic bar 5 is arranged in the axis of the electromagnetic control roller 1, the roller temperature sensors 3 are uniformly distributed on the upper side and the lower side of the inner hole wall of the roller corresponding to the induction heating area of the electromagnetic bar 5 and used for detecting the temperature of the inner wall of the roller in the corresponding area, the circumferential surface of the electromagnetic bar 5 is provided with annular grooves 51 which are equidistantly spaced and correspond to the roller temperature sensors 3 on the upper side and the lower side, the induction coil temperature sensors 2 are uniformly distributed on the upper side and the lower side of the induction coil of the electromagnetic bar 5, the induction coil temperature sensors 2 are correspondingly distributed on the inner side of the roller temperature sensor 3, and the number of the roller temperature sensors 3 and the number of the induction coil temperature sensors 2 are equal to the number of the induction heating areas on the electromagnetic bar 5 and used for; the signal slip ring 6 is arranged at the right end part of the electromagnetic control roller 1, the induction coil temperature sensor 2 and the roller temperature sensor 3 are respectively connected to a signal acquisition and analysis system 7 through the signal slip ring 6, and the connection mode is shunting multi-channel connection, so that the synchronous multi-channel detection function can be realized; the thermal imaging instrument 4 is arranged on the outer side of the electromagnetic control roller 1, an image acquisition area of the thermal imaging instrument can project towards the electromagnetic control roller, and the center of the projection area 41 is positioned at the center of the axis of the roller body of the electromagnetic control roller 1 and is used for acquiring the temperature distribution and the history change of the whole length of the roller body of the roller; the temperature image acquired by the thermal imager 4 can correspond to the regulation and control area of the electromagnetic rod 5, so that the temperature change of each regulation and control area is acquired; the thermal imaging instrument 4 can be connected to an image processing computer and used for acquiring the distribution condition of the temperature field on the surface of the roller in real time, and the temperature field isotherm and the temperature data of the mark point can be acquired after image processing.

The symmetry of both ends face axle center department about electromagnetic rod 5 is provided with the axial hole 52 of circumference equipartition, the degree of depth of axial hole 52 equals the length of 5 terminal surfaces of electromagnetic rod to its induction heating district central point and puts, just the quantity of axial hole 52 is twice of 5 induction heating district quantity of electromagnetic rod, induction coil temperature sensor 2 corresponds the inside that sets up at axial hole 52 respectively, just the tip of 2 probes of induction coil sensor contacts with the bottom of axial hole 52.

When the device is used for monitoring the roller shape, the electromagnetic regulating and controlling roller 1 can be connected to an induction heating variable frequency power supply, and the shunt control of an induction coil of an electromagnetic rod 5 can be realized by the control of the induction heating variable frequency power supply; the induction heating variable frequency power supply is internally provided with a signal acquisition module and a signal conversion module, and can read, store and output the current parameter and the frequency parameter of the induction coil of the electromagnetic rod 5 in real time; the induction heating variable frequency power supply is connected to an upper computer PLC, and parameters such as current quantity, frequency and the like output to the electromagnetic regulation and control roller 1 can be dynamically regulated and controlled by the upper computer PLC.

The graphic processing computer, the signal acquisition and analysis system 7 and the upper computer PLC can be connected to an electromagnetic regulation and control computer; wherein, the image processing computer can provide the processed temperature f (xi) of the i area of the roll surface for the electromagnetic adjusting and controlling computer; the signal acquisition and analysis system 7 can provide the roller inner wall temperature TRi and the induction coil temperature TDi in the roller shape regulation process for the electromagnetic regulation and control computer; the upper computer PLC can write in the roll shape regulation and control parameters according to a target roll shape calculation result preset in the electromagnetic regulation and control computer, and form PLC language instructions to be transmitted to the induction heating variable frequency power supply.

The roller surface temperature field information, the roller temperature information, the induction coil temperature information and the information transmitted to the upper computer PLC, which are received by the electromagnetic adjusting and controlling computer, are stored in a roller type database, so that the temperature field-roller type data can be further enriched.

A visual sensing electromagnetic regulation and control roller shape monitoring method comprises the following steps:

s1, connecting the electromagnetic control roller 1 with an induction heating variable frequency power supply, connecting the thermal imager 4 with an image processing computer, simultaneously connecting the induction heating variable frequency power supply with an upper computer PLC, and respectively connecting the upper computer PLC, the image processing computer and the signal acquisition and analysis system 7 with the electromagnetic control computer; the electromagnetic adjusting and controlling computer reads the temperature signal TDi of the induction coil, the internal temperature TRi of the roller and the section temperature f (xi) of the roller surface i at the same time interval;

s2, inputting a target roll shape R (-2e-12x6-5e-20x5+1e-07x4+1e-14x3-0.0018x2+9e-11x +23.878) × 10-3+135mm into an electromagnetic regulation computer, equally dividing the target roll shape into ten sections, and inputting structural parameters of the electromagnetic regulation roll 1, including a diameter Dr of the electromagnetic regulation roll being 270mm, a length L of a roll body of the electromagnetic regulation roll being 600mm, a diameter Dd of an electromagnetic rod being 100mm, a number i of induction heating sections of the electromagnetic rod being 2, a length Li of each induction heating section of the electromagnetic rod being 25mm, a number k of contact sections being 1, and a length Lk of each contact section of the electromagnetic rod 5 being 50 mm;

s3, inputting preset electromagnetic parameters of the target roller shape, wherein the preset electromagnetic parameters comprise current density Ji of each induction heating area which is 3A-mm-2, frequency fi which is 400Hz, and roller shape adjusting time ti of each section which is 600S;

s4, initializing the system before starting, and initializing the thermal imager 4, the roller temperature sensor 3 and the induction coil temperature sensor 2;

s5: acquiring induction coil temperature signals TD 1-TD 8 and roller internal temperatures TR 1-TR 4 through a signal acquisition and analysis system 7, and matching the induction coil temperature signals TD 1-TD 8 and the roller internal temperatures TR 1-TR 4 with parameter groups of each section of the electromagnetic rod 5;

s6, acquiring a roller surface temperature distribution image through the thermal imager 4, and performing gray level processing on a roller body temperature field image through an image processing computer based on a machine vision technology to acquire a gray level matrix g (800, 600);

s7, dividing the gray matrix into 2 sections, wherein the length of each section is equal to the length of a contact area of an electromagnetic rod 5 in the electromagnetic control roller 1 of the section plus the average value of induction heating areas on two sides of the length of the contact area, namely lk + (li + li +1)/2 is 75 mm;

s8, matching the maximum gray value of 255 with the global maximum temperature fed back by the thermal imager 4, matching the minimum gray value of 0 with the global minimum temperature fed back by the thermal imager 4 of 30 ℃, and then obtaining the temperature range [30, 150] corresponding to the gray range [0, 255 ].

S9, obtaining a gray-scale contour fj (800, 600) by a gray-scale matrix g (800, 600), judging the crossing condition of the gray-scale contour fj (800, 600) and the gray-scale section divided in the step S7 by the system, and obtaining the temperature distribution condition of the crossing position according to the gray-scale-temperature mapping relation obtained in the step S8;

and S10, matching and addressing in a temperature field-roller shape database built in the system according to the temperature rule obtained by calculation in the steps S4 and S8, the initial parameters in the step S2 and other information, and obtaining the real-time roller shape.

The above-mentioned embodiments are merely illustrative of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and various modifications and improvements of the technical solution of the present invention by those skilled in the art should fall within the protection scope defined by the claims of the present invention without departing from the spirit of the present invention.