阅读说明：本技术 多刀盘顶管机的防干涉控制方法及装置 (Anti-interference control method and device for multi-cutter-disc pipe jacking machine ) 是由 郑康泰 林福龙 陈力 陈家浩 蒋鹏鹏 孟启明 华翔 胡鹏 徐淼 董科 于 2021-08-31 设计创作，主要内容包括：本发明公开了一种多刀盘顶管机的防干涉控制方法及装置,方法包括：获得多刀盘顶管机中各刀盘的位置角和转动速度；将所述位置角和转动速度输入状态空间表达式模型,预测刀盘间的转动角度差；根据所述转动角度差,确定期望输出序列；根据转动角度差,期望输出序列和优化准则方程,进行多刀盘顶管机的防干涉控制。本发明可以防止多刀盘顶管机干涉,避免安全隐患。(The invention discloses an anti-interference control method and device for a multi-cutter-disc push bench, wherein the method comprises the following steps: obtaining the position angle and the rotating speed of each cutter head in the multi-cutter head push bench; inputting the position angle and the rotation speed into a state space expression model, and predicting the rotation angle difference between the cutter heads; determining an expected output sequence according to the rotation angle difference; and performing interference prevention control on the multi-cutter-disc push bench according to the rotation angle difference, the expected output sequence and the optimization criterion equation. The invention can prevent the interference of the multi-cutter-disc push bench and avoid potential safety hazards.)

1. An interference prevention control method for a multi-cutter-disc push bench is characterized by comprising the following steps:

obtaining the position angle and the rotating speed of each cutter head in the multi-cutter head push bench;

inputting the position angle and the rotation speed into a state space expression model, and predicting the rotation angle difference between the cutter heads;

determining an expected output sequence according to the rotation angle difference;

and performing interference prevention control on the multi-cutter-disc push bench according to the rotation angle difference, the expected output sequence and the optimization criterion equation.

2. The interference prevention control method of the multi-cutter push bench of claim 1 wherein the state space expression model comprises a control matrix, a state matrix, an output matrix and a feed forward matrix, the state matrix and the feed forward matrix being zero squares, the output matrix being an identity diagonal matrix;

inputting the position angle and the rotating speed into a state space expression model, predicting the rotating angle difference between the cutter heads, and comprising the following steps: inputting the position angle and the rotation speed into a control matrix to obtain an angle difference variable quantity; and predicting the rotation angle difference among the cutterheads according to the angle difference variable quantity, the state matrix, the output matrix and the feedforward matrix.

3. The interference prevention control method of the multi-cutter push bench of claim 1, wherein the interference prevention control of the multi-cutter push bench according to the rotation angle difference, the expected output sequence and the optimization criterion equation comprises:

inputting the rotation angle difference and the expected output sequence into an optimization criterion equation, and determining a control increment which enables the cost function to be minimum;

and performing interference prevention control on the multi-cutter-disc push bench according to the control increment.

4. The interference prevention control method of the multi-cutter push bench of claim 3, wherein the optimization criterion equation is as follows:

wherein J is a cost function,and the predicted value of the rotation angle difference of the j-th step in the future in the k-th control step is w (k + j) which is the predicted value of the j-th step in the future of the expected output sequence, the lambda (j) is the weight of the control quantity of the j-th step, and the delta u is the control increment.

5. The utility model provides a multi-cutter disc pipe push bench prevent interference controlling means which characterized in that includes:

the acquisition module is used for acquiring the position angle and the rotating speed of each cutter head in the multi-cutter head pipe push bench;

the prediction module is used for inputting the position angle and the rotation speed into a state space expression model and predicting the rotation angle difference between the cutter heads;

the sequence determining module is used for determining an expected output sequence according to the rotation angle difference;

and the control module is used for performing interference prevention control on the multi-cutter-disc push bench according to the rotation angle difference, the expected output sequence and the optimization criterion equation.

6. The apparatus of claim 5, wherein said state space expression model comprises a control matrix, a state matrix, an output matrix and a feedforward matrix, said state matrix and feedforward matrix being zero-squares, said output matrix being an identity-diagonal matrix;

the control module is further to: inputting the position angle and the rotation speed into a control matrix to obtain an angle difference variable quantity; and predicting the rotation angle difference among the cutterheads according to the angle difference variable quantity, the state matrix, the output matrix and the feedforward matrix.

7. The interference prevention control device of the multi-disc push bench of claim 5, wherein the control module is further configured to:

inputting the rotation angle difference and the expected output sequence into an optimization criterion equation, and determining a control increment which enables the cost function to be minimum;

and performing interference prevention control on the multi-cutter-disc push bench according to the control increment.

8. The interference prevention control device for the multi-cutter push bench of claim 7 wherein the optimization criteria equation is:

wherein J is a cost function,and the predicted value of the rotation angle difference of the j-th step in the future in the k-th control step is w (k + j) which is the predicted value of the j-th step in the future of the expected output sequence, the lambda (j) is the weight of the control quantity of the j-th step, and the delta u is the control increment.

9. A computer device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor implements the method of any one of claims 1 to 4 when executing the computer program.

10. A computer-readable storage medium, characterized in that the computer-readable storage medium stores a computer program for executing the method of any one of claims 1 to 4.

Technical Field

The invention relates to the technical field of tunnel tunneling, in particular to an anti-interference control method and device of a multi-cutter-disc pipe jacking machine.

Background

The pipe jacking machine is one kind of tunnel boring machine, and has arranged a plurality of blade discs on the excavation face. When the jacking pipe is designed, the excavation rate needs to be improved as much as possible, therefore, the excavation surfaces of the cutterheads are often overlapped, if the cutterheads need to be arranged in the front and back direction for preventing interference, the mode is easy to cause cutter clamping. The cutter clamping can be avoided due to the co-planar arrangement, and the adaptability is better in harder strata and complex strata; coplanar arrangement in order to improve the excavation rate as much as possible, the cutter heads need to be arranged in a staggered manner, namely, the tracks of the cutter heads are overlapped. However, the tracks of the cutter heads are overlapped and easily interfere with each other in the tunneling process, and even the cutter heads are broken, so that potential safety hazards are brought.

Therefore, an anti-interference control scheme for a multi-cutter push bench that can overcome the above problems is needed.

Disclosure of Invention

The embodiment of the invention provides an interference prevention control method of a multi-cutter-disc push bench, which is used for preventing the interference of the multi-cutter-disc push bench and avoiding potential safety hazards and comprises the following steps:

obtaining the position angle and the rotating speed of each cutter head in the multi-cutter head push bench;

inputting the position angle and the rotation speed into a state space expression model, and predicting the rotation angle difference between the cutter heads;

determining an expected output sequence according to the rotation angle difference;

and performing interference prevention control on the multi-cutter-disc push bench according to the rotation angle difference, the expected output sequence and the optimization criterion equation.

The embodiment of the invention provides an interference prevention control device of a multi-cutter-disc push bench, which is used for preventing the interference of the multi-cutter-disc push bench and avoiding potential safety hazards and comprises the following components:

the acquisition module is used for acquiring the position angle and the rotating speed of each cutter head in the multi-cutter head pipe push bench;

the prediction module is used for inputting the position angle and the rotation speed into a state space expression model and predicting the rotation angle difference between the cutter heads;

the sequence determining module is used for determining an expected output sequence according to the rotation angle difference;

and the control module is used for performing interference prevention control on the multi-cutter-disc push bench according to the rotation angle difference, the expected output sequence and the optimization criterion equation.

The embodiment of the invention also provides computer equipment which comprises a memory, a processor and a computer program which is stored on the memory and can run on the processor, wherein the processor executes the interference prevention control method of the multi-cutter pipe push bench.

The embodiment of the invention also provides a computer readable storage medium, which stores a computer program for executing the interference prevention control method of the multi-cutter push bench.

In the embodiment of the invention, the position angle and the rotating speed of each cutter head in the multi-cutter head pipe push bench are obtained; inputting the position angle and the rotation speed into a state space expression model, and predicting the rotation angle difference between the cutter heads; determining an expected output sequence according to the rotation angle difference; and performing interference prevention control on the multi-cutter-disc push bench according to the rotation angle difference, the expected output sequence and the optimization criterion equation. According to the embodiment of the invention, the state space expression model is utilized to predict the rotation angle difference between the cutterheads, the optimization criterion equation is utilized to carry out control increment optimization, and the speed compensation of the cutterheads is applied, so that the cutterheads are prevented from interfering and colliding, and potential safety hazards are avoided.

Drawings

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 described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts. In the drawings:

FIG. 1 is a schematic diagram of an interference prevention control method of a multi-cutter head push bench according to an embodiment of the present invention;

FIG. 2 is a schematic representation of a multiple cutter disc path in an embodiment of the present invention;

FIG. 3 is a structural diagram of an interference prevention control device of a multi-cutter head push bench in the embodiment of the invention;

fig. 4 is a schematic structural diagram of a computer device according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the embodiments of the present invention are further described in detail below with reference to the accompanying drawings. The exemplary embodiments and descriptions of the present invention are provided to explain the present invention, but not to limit the present invention.

In order to prevent interference of a multi-cutter-disc push bench and avoid potential safety hazards, an embodiment of the present invention provides an interference prevention control method for a multi-cutter-disc push bench, as shown in fig. 1, the method may include:

step 101, obtaining the position angle and the rotation speed of each cutter head in the multi-cutter-head push bench;

102, inputting the position angle and the rotation speed into a state space expression model, and predicting the rotation angle difference between cutterheads;

103, determining an expected output sequence according to the rotation angle difference;

and step 104, performing interference prevention control on the multi-cutter-disc push bench according to the rotation angle difference, the expected output sequence and the optimization criterion equation.

As can be known from the illustration of FIG. 1, the embodiment of the invention obtains the position angle and the rotation speed of each cutter head in the multi-cutter head push bench; inputting the position angle and the rotation speed into a state space expression model, and predicting the rotation angle difference between the cutter heads; determining an expected output sequence according to the rotation angle difference; and performing interference prevention control on the multi-cutter-disc push bench according to the rotation angle difference, the expected output sequence and the optimization criterion equation. According to the embodiment of the invention, the state space expression model is utilized to predict the rotation angle difference between the cutterheads, the optimization criterion equation is utilized to carry out control increment optimization, and the speed compensation of the cutterheads is applied, so that the cutterheads are prevented from interfering and colliding, and potential safety hazards are avoided.

In the embodiment, the position angle and the rotating speed of each cutter head in the multi-cutter-head push bench are obtained; and inputting the position angle and the rotation speed into a state space expression model, and predicting the rotation angle difference between the cutter heads.

In this embodiment, the state space expression model includes a control matrix, a state matrix, an output matrix and a feedforward matrix, where the state matrix and the feedforward matrix are zero square matrices, and the output matrix is a unit diagonal matrix;

inputting the position angle and the rotating speed into a state space expression model, predicting the rotating angle difference between the cutter heads, and comprising the following steps: inputting the position angle and the rotation speed into a control matrix to obtain an angle difference variable quantity; and predicting the rotation angle difference among the cutterheads according to the angle difference variable quantity, the state matrix, the output matrix and the feedforward matrix.

In an embodiment, an expected output sequence is determined according to the rotation angle difference; and performing interference prevention control on the multi-cutter-disc push bench according to the rotation angle difference, the expected output sequence and the optimization criterion equation.

In this embodiment, performing interference prevention control on the multi-cutter push bench according to the rotation angle difference, the expected output sequence and the optimization criterion equation includes:

inputting the rotation angle difference and the expected output sequence into an optimization criterion equation, and determining a control increment which enables the cost function to be minimum;

and performing interference prevention control on the multi-cutter-disc push bench according to the control increment.

In this embodiment, the optimization criterion equation is:

wherein J is a cost function,and the predicted value of the rotation angle difference of the j-th step in the future in the k-th control step is w (k + j) which is the predicted value of the j-th step in the future of the expected output sequence, the lambda (j) is the weight of the control quantity of the j-th step, and the delta u is the control increment. The meaning of this formula is: in the kth control period, the predicted output values of the future n steps are calculated, subtracted from the expected output values of the n steps, and then the differences are accumulated, and a control increment delta u is applied to each step in the future m steps (m is less than or equal to n), and is also accumulated and added with the accumulation result of the prediction part.

A specific embodiment is given below to describe a specific application of the interference prevention control of the multi-cutter-disc push bench in the embodiment of the present invention. Fig. 2 is a diagram of a two-layer-eight-cutter-four-swath-coplanar rotation layout and cutter trajectory in this embodiment. The tracks of the cutter heads are overlapped, mutual interference is easy to occur in tunneling, even the cutter heads are broken, and an anti-interference control algorithm needs to be designed to prevent the cutter heads from mutual interference. Each cutter head needs to be additionally provided with an absolute position encoder, and the absolute position encoder can measure the absolute angle of the rotating object rotating relative to a zero reference line. The extension line of one spoke is selected as a rotation reference line, and the radial line which starts from the center of the cutter head and is horizontally right is used as a reference zero initial line, so that the rotation angle of each cutter head relative to the zero initial line and the position angle of each spoke can be obtained. The angle difference for controlling the rotation of the adjacent cutter heads is constant, because the included angles between the spokes on a single cutter head are the same, the angle difference is constantly set to be half of the included angle between two spokes, namely an alpha angle, and each cutter head has four spokes, and the alpha is 45 degrees. The purpose of the anti-interference control algorithm is to control the angle difference of the rotation of the adjacent cutterheads to be kept near 45 degrees. An anti-interference controller is designed to apply a cutter head speed compensation signal to ensure that the cutter head cannot interfere and collide, and a linear system prediction algorithm established in a digital discrete system such as a computer is used for controlling and is divided into two parts of prediction and control quantity optimization. Firstly, a system model, namely a state space expression model is established(dynamic model of control object). The state space expression model is built as follows: assuming that p cutter heads are provided in total, the angle difference between p and e cutter heads needs to be controlled, and the value of e is determined by the cutter head arrangement mode. For example eight cutter heads, in a row there are 7 pairs of interference relationships, e being 7. If two rows are shown in FIG. 2, there are 10 pairs of interference relationships, and e is 10. Taking the double-layer multi-cutter layout of fig. 2 as an example, let the absolute value of the speed of the adjacent No. 1 and No. 2 cutter be V₁、V₂Actually, the rotation directions of two adjacent cutter heads are opposite; before the cutter heads are started, the current cutter head position angle needs to be read as the initial value of the angle difference, and the variation of the rotation angle difference of the two cutter headsAnd the equation system of a group of angle differences is obtained by analogy, wherein 1/s is an integral operator:

the derivative of this system of equations is:

the derivative of the equation set is a control matrix of the state space expression model, the state matrix A of the system is a zero square matrix with a dimension of 10, the control matrix B of the system is a matrix with a dimension of 10 multiplied by 8, the observation matrix C of the system is a unit diagonal matrix with a dimension of 10, and the feedforward matrix of the system is a zero matrix with a dimension of 10. The model prediction algorithm utilizes the system model established by the control matrix to solve the preset speed of the cutter head numbered i #, and the preset speed is obtainedBut not the output control amount of the controller. Assuming that i is 4, the output of the controller for the angular difference Δ 3 to be controlled isMinusDifference of (2)Will be provided withThe speed controllers respectively sent to the No. 3 cutter head and the No. 4 cutter head are used as speed compensation; the specific mode of speed compensation is as follows: suppose that the No. 4 cutter head is arranged to lead the No. i rotation angle by alpha, ifWhen in use, willNegative feedback is given to the 3# cutter disc controller, and the feedback obtained by the 4# cutter disc is 0; if it isWhen in use, willThe feedback is fed back to the No. 4 cutter disc controller, and the feedback obtained by the No. 3 cutter disc is 0; the arrangement is that the angle difference between the cutter heads is realized through relative speed reduction, and the purpose is to prevent the cutter heads from still obtaining an acceleration instruction when encountering obstacles or even cutter clamping, and causing overheating burnout of a motor or breakage of a main drive. The control matrix, the state matrix, the output matrix and the feedforward matrix of the system jointly form a state space expression of the system, namely a dynamic model of the system. The model is brought into a model prediction control process to predict output of n steps in the future, a control period T is set in a prediction part, the T is integral multiple of sampling time of a computer, one period is called as one step, an angle difference output value y (k + J) of the system in the n steps in the future is predicted according to a step response model of the model and a set prediction step length n, a predicted value is brought into an optimization process, delta u (1) and delta u (2) … delta u (m) of control increments are calculated to enable a cost function J to be minimum, then only the first step of control increment delta u (1) is implemented in the control step, the rest of control increments are abandoned, and the prediction curve prediction of the n steps in the future and the calculation of the m step of control increments are output and only the first step of control increments are implemented after the next control step, and the process is repeated.

The predictive computation uses the column vector formed by the system model (A, B, C, D), y (k + j) as described aboveIs composed ofBy y₀(k+1),y₀(k+2)...y₀(k+j)...y₀(k + n) composition, y₀(k + j) is the summation of the j-th step control quantity in the future n-step output predicted at all the previous moments:

the most important step here is the control increment optimization process, and the optimization criterion equation is as follows:

wherein J is a cost function,the predicted value of the rotation angle difference of the next j step in the kth control step, w (k + j) is the predicted value of the next j step of the expected output sequence, lambda (j) is the weight of the control quantity of the j step, delta u is the control increment and contains m future control quantities [ delta u₁,Δu₂,…Δu_m]Is Δ U. The goal of the optimization is to find the m-step control increments such that the cost function J is minimal in these n steps, but only the first step control increment is output, and the remainder are discarded. The desired output sequence is a smooth approximation to the reference input value, typically taking: w (k + j) ═ α^jy(k)+(1-α^j)y_rWherein, alpha is a softening coefficient, 0<α<1, y (k) is the actual output value of the system, y_rIs a reference input, here constant a. To findSequence of

ΔU＝(A^TA+λI)^-1A^T(W-Y₀)

In future m-step control, to implement closed-loop control, only the first quantity of Δ U is implemented, namely:

Δu(k)＝C^T(A^TA+λI)^-1A^T(W-Y₀)

wherein C is^T＝[1 0…0]；

Δ u (k) is integrated to obtainIn specific implementation, the prediction step length n, the control step length m, the control quantity weight λ and the softening coefficient α need to be adjusted according to the debugging effect.

In order to introduce the measured value of the absolute position encoder to form a closed-loop control, the actual angle difference y (k +1) measured at the time (k +1) needs to be introduced into the feedback at the time (k +1) after the control Δ u is performed.

Let the prediction error at (k +1) time at the previous time be

Correcting the predicted y at the time k to obtain

h_jAnd (d) correcting coefficients predicted for the (k + j) th step predicted at the time k.

The initial value of the prediction at the (k + j) th time isThe above procedure of the closed-loop model prediction algorithm can be seen in its standard flow.

In the embodiment of the invention, the cutter heads are additionally provided with absolute position encoders which can be coaxially arranged or arranged on the side surface, the initial zero lines are all horizontal rays, and the rotation directions of adjacent cutter heads are necessarily opposite. And establishing a data path between the industrial personal computer and the PLC, and establishing a data path between the frequency converter board card and the PLC. And reading the rotating speed of the cutter head and the value of the encoder, and sending the values to the industrial personal computer. And the industrial personal computer calculates and sends the data to the frequency converter. And (6) debugging parameters on site.

Based on the same inventive concept, the embodiment of the invention also provides an anti-interference control device of the multi-cutter-disc pipe push bench, which is described in the following embodiment. Because the principle of solving the problems is similar to the anti-interference control method of the multi-cutter-disc push bench, the implementation of the device can refer to the implementation of the method, and repeated parts are not described again.

Fig. 3 is a structural diagram of an interference prevention control device of a multi-cutter pipe push bench according to an embodiment of the present invention, and as shown in fig. 3, the device includes:

an obtaining module 301, configured to obtain a position angle and a rotation speed of each cutter in a multi-cutter push bench;

a prediction module 302, configured to input the position angle and the rotation speed into a state space expression model, and predict a rotation angle difference between cutter heads;

a sequence determining module 303, configured to determine an expected output sequence according to the rotation angle difference;

and the control module 304 is used for performing interference prevention control on the multi-cutter-disc push bench according to the rotation angle difference, the expected output sequence and the optimization criterion equation.

In one embodiment, the state space expression model comprises a control matrix, a state matrix, an output matrix and a feedforward matrix, wherein the state matrix and the feedforward matrix are zero square matrixes, and the output matrix is an unit diagonal matrix;

the control module 304 is further configured to: inputting the position angle and the rotation speed into a control matrix to obtain an angle difference variable quantity; and predicting the rotation angle difference among the cutterheads according to the angle difference variable quantity, the state matrix, the output matrix and the feedforward matrix.

In one embodiment, the control module 304 is further configured to:

inputting the rotation angle difference and the expected output sequence into an optimization criterion equation, and determining a control increment which enables the cost function to be minimum;

and performing interference prevention control on the multi-cutter-disc push bench according to the control increment.

In one embodiment, the optimization criteria equation is:

wherein J is a cost function,and the predicted value of the rotation angle difference of the j-th step in the future in the k-th control step is w (k + j) which is the predicted value of the j-th step in the future of the expected output sequence, the lambda (j) is the weight of the control quantity of the j-th step, and the delta u is the control increment.

In summary, in the embodiment of the present invention, the position angle and the rotation speed of each cutter head in the multi-cutter head push bench are obtained; inputting the position angle and the rotation speed into a state space expression model, and predicting the rotation angle difference between the cutter heads; determining an expected output sequence according to the rotation angle difference; and performing interference prevention control on the multi-cutter-disc push bench according to the rotation angle difference, the expected output sequence and the optimization criterion equation. According to the embodiment of the invention, the state space expression model is utilized to predict the rotation angle difference between the cutterheads, the optimization criterion equation is utilized to carry out control increment optimization, and the speed compensation of the cutterheads is applied, so that the cutterheads are prevented from interfering and colliding, and potential safety hazards are avoided.

Based on the aforementioned inventive concept, as shown in fig. 4, the present invention further provides a computer apparatus 400, which includes a memory 410, a processor 420, and a computer program 430 stored in the memory 410 and operable on the processor 420, wherein the processor 420 executes the computer program 430 to implement the interference prevention control method of the multi-cutter pipe push bench.

Based on the above inventive concept, the present invention provides a computer-readable storage medium, which stores a computer program, and the computer program, when executed by a processor, implements the interference prevention control method for the multi-cutter push bench.

As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

Finally, it should be noted that: the above-mentioned embodiments are only specific embodiments of the present invention, which are used for illustrating the technical solutions of the present invention and not for limiting the same, and the protection scope of the present invention is not limited thereto, although the present invention is described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: any person skilled in the art can modify or easily conceive the technical solutions described in the foregoing embodiments or equivalent substitutes for some technical features within the technical scope of the present disclosure; such modifications, changes or substitutions do not depart from the spirit and scope of the embodiments of the present invention, and they should be construed as being included therein. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.