Strip slippage under coiler tension control method

Abstract

The application provides a coiling machine tension control method under strip slip, comprising the following steps: S001: establishing a tension equation and a tension control model of the coiling machine; S002: establishing a dynamic estimator of a strip slip term to obtain an estimated value of the strip slip term; S003: designing a mandrel linear velocity active compensation module for the strip slip term; S004: designing a mandrel linear velocity set value under a zero slip condition based on a proportional feedback method; S005: calculating a mandrel angular velocity command value by using the mandrel linear velocity command value; and S006: controlling the operation of a coiling machine motor based on the designed mandrel angular velocity command value.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of tension control of coiler in metallurgical industry, and particularly relates to a tension control method of coiler under strip slippage. BACKGROUND

[0002] Coiler is widely used in steel, non-ferrous metal and other industries, and its main function is to wind strip into a coil. The use of coiler to wind strip into a coil not only realizes continuous production of strip, but also reduces the occupied area of inventory, and is convenient for storage and transportation. According to the production process requirements, a certain tension needs to be applied during the winding process, and the tension control precision directly affects the product quality, so the tension regulation of coiler is the core problem. In the normal winding process, on the one hand, the constancy of the tension needs to be maintained, and on the other hand, the constancy of the speed of the unit also needs to be ensured. In the constant tension control system, the difference between the line speed of the pinch roll and the line speed of the mandrel is used to make the strip produce a certain amount of elastic deformation, so as to maintain a certain tension, and then the winding operation is carried out smoothly. Therefore, in the process of constant tension winding of the strip, the line speed of the pinch roll and the line speed of the mandrel need to be adjusted in real time, so that the tension of the strip can be kept at the tension set value. Since the line speed of the pinch roll has been set in advance, the line speed of the mandrel needs to be precisely calculated and controlled in the process of strip tension regulation. In the actual working process, since the speed of the strip and the speed of the pinch roll cannot be completely synchronized, there is a relative slippage between them, and the slippage amount and the slippage influence coefficient cannot be obtained, so the tension regulation precision is also reduced. In view of the slippage phenomenon of the strip at the pinch roll, the winding quality of the coiler is affected. SUMMARY

[0003] In view of this, the purpose of the present application is to provide a tension control method of coiler under strip slippage, which is used to overcome the above problems or at least partially solve or alleviate the above problems.

[0004] The present application provides a tension control method of coiler under strip slippage, which comprises the following steps:

[0005] S001: establishing a tension equation and a tension control model of the coiler;

[0006] S002: establishing a dynamic estimator of the strip slippage term to obtain an estimated value of the strip slippage term;

[0007] S003: designing a mandrel line speed active compensation module for the strip slippage term;

[0008] S004: designing a mandrel line speed set value under the condition of zero slippage based on the proportional feedback method;

[0009] S005: calculating the command value of the mandrel angular velocity by using the command value of the mandrel line speed;

[0010] S006: controlling the coiler motor to operate based on the designed mandrel angular velocity instruction value.

[0011] In step S001, a tension equation of the coiler is established:

[0012]

[0013] where T(t)∈R is the tension of the strip at time t, v1(t)∈R is the linear speed of the pinch roll at time t, v2(t)∈R is the linear speed of the mandrel at time t, A∈R is the cross-sectional area of the strip, E∈R is the elastic deformation coefficient of the strip, l∈R is the travel of the strip from the pinch roll to the mandrel, S∈R is the unknown slip amount of the strip, and a∈R is the unknown slip amount influence coefficient of the strip.

[0014] Since contains the unknown slip amount S of the strip and the unknown slip amount influence coefficient a, the known information part is used to establish a tension control model as follows:

[0015]

[0016] where is the unknown slip term of the strip in the tension equation.

[0017] In step S002,

[0018] where is the tension estimation value of the strip given by the dynamic estimator at time t, is the unknown slip term estimation value given by the dynamic estimator at time t, l1∈R is the gain parameter 1 of the dynamic estimator of the slip term of the strip, and l2∈R is the gain parameter 2 of the dynamic estimator of the slip term of the strip.

[0019] In step S003, based on the tension control model and the unknown slip term estimation value given by the dynamic estimator at time t, a mandrel linear speed active compensation module for the slip term of the strip is designed;

[0020]

[0021] where is the mandrel linear speed instruction value at time t, v 2u (t)∈R is the mandrel linear speed setting value under the condition of zero slip amount of the strip at time t, active compensation of the unknown slip term is achieved.

[0022] In step S004, the mandrel linear speed setting value

[0023]

[0024] wherein T r (t)∈R is the tension setting value at time t, k p ∈R is the proportional gain coefficient.Combining (4) and (5), the mandrel linear velocity command value

[0025]

[0026] In step S005, the mandrel linear velocity command value is calculated.

[0027] The calculated mandrel linear velocity command value is used to calculate the mandrel angular velocity command value

[0028]

[0029] wherein is the angular velocity command value of the mandrel at time t, and r2∈R is the radius of the strip coil.

[0030] The strip-slippage-based coiler tension control method of the present application establishes a dynamic estimator for the strip-slippage term, obtains the estimated value of the strip-slippage term in real time, and establishes the mandrel linear velocity setting value with active compensation of the strip-slippage term, thereby avoiding the influence of the strip-slippage phenomenon on the tension control precision. The present application neither relies on the specific slippage amount and slippage influence coefficient nor needs real-time autonomous adjustment, and thus improves the tension control precision under various working conditions and for different materials, thereby improving the coiling quality of the coiler. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is a typical coiling section process layout diagram;

[0032] Figure 2 is a flowchart of the method of the present application;

[0033] Figure 3 is a tension change diagram under scenario one;

[0034] Figure 4 is a tension change diagram under scenario two.

[0035] In the above diagrams: 1 is a pinch roll; 2 is a coiler; and 3 is a strip coil.

[0036] The present application will be further described in detail below in combination with the drawings and examples. DETAILED DESCRIPTION

[0037] Symbol explanation:

[0038] R: a set consisting of all real numbers;

[0039] t: running time of the coiler system, t ∈ [0,∞);

[0040] T(t): strip tension at time t, T(t) ∈ R;

[0041] v1(t): line speed of the pinch roll at time t, v1(t) ∈ R;

[0042] v2(t): line speed of the mandrel at time t, v2(t) ∈ R;

[0043] A: cross-sectional area of the strip, A ∈ R;

[0044] E: coefficient of elastic deformation of the strip, E ∈ R;

[0045] l: travel of the strip from the pinch roll to the mandrel, l ∈ R;

[0046] S: slip amount of the strip, S ∈ R;

[0047] α: slip amount influence coefficient of the strip, α ∈ R;

[0048] f(v1, T): unknown slip term of the strip in the tension equation, f(v1, T) ∈ R;

[0049] strip tension estimate value given by the dynamic estimator at time t,

[0050] unknown slip term estimate value of the strip given by the dynamic estimator at time t,

[0051] l1: gain parameter 1 of the dynamic estimator of the slip term of the strip, l1 ∈ R;

[0052] l2: gain parameter 2 of the dynamic estimator of the slip term of the strip, l2 ∈ R;

[0053] mandrel line speed command value at time t,

[0054] v 2u (t): mandrel line speed set value under the condition of zero slip amount of the strip at time t, v 2u (t) ∈ R;

[0055] T r (t): tension set value at time t, T r (t) ∈ R;

[0056] k p : proportional gain coefficient, k p∈ R;

[0057] ω 2 (t) : the angular velocity of the mandrel at time t, ω 2 (t) ∈ R.

[0058] r 2 : the radius of the coil, r 2 ∈ R.

[0059] ω 2 (t) : the angular velocity of the mandrel at time t, ω 2 (t) ∈ R.

[0060] A typical coiling section process arrangement is shown in Figure 1 , which mainly includes pinch rolls 1, a coiler 2, and a coil formed by the strip under the action of tension T(t).

[0061] The actual parameters of the coiler and the strip are: E = 2.2 × 10 5 (N / mm 2 ), α = 1 × 10 -5 , v 1 = 10 (m / s), l = 10 (m), A = 600 (mm 2 ), T r (t) = 1000000 (N), r 2 = 0.2 (m).

[0062] The present application proposes a coiler tension control method under strip slip, which includes the following steps: as shown in Figure 2 , S001: establishing a tension equation and a tension control model of the coiler; S002: establishing a dynamic estimator of the strip slip term to obtain an estimated value of the strip slip term; S003: designing a mandrel linear velocity active compensation module for the strip slip term; S004: designing a mandrel linear velocity set value under the condition of zero slip amount based on the proportional feedback method; S005: calculating the mandrel angular velocity command value using the mandrel linear velocity command value; and S006: controlling the coiler motor to operate based on the designed mandrel angular velocity command value.

[0063] Specific implementation step S001: establishing a tension equation (1) and a tension control model (2) of the coiler, and using the actual parameters of the coiler and the strip, the tension equation is:

[0064]

[0065] The tension control model is:

[0066]

[0067] wherein is an unknown strip slip term in the tension equation.

[0068] Specific implementation step S002: establishing a total acceleration dynamic estimator based on the sum of tracking error signals:

[0069]

[0070] Where the gain parameters of the dynamic estimator of the strip slip term are selected as l1=100, l2=2500.

[0071] Specific implementation step S003: based on the tension control model obtained in step S001, and the unknown strip slip term estimation value given by the dynamic estimator at time t obtained in step S002, a mandrel linear velocity active compensation module for the strip slip term is designed:

[0072]

[0073] Specific implementation step S004: based on the proportional feedback method, the mandrel linear velocity set value under the condition of zero slip is designed:

[0074]

[0075] Further, the mandrel linear velocity command value is obtained:

[0076]

[0077] Where k p =3.

[0078] Specific implementation step S005: using the calculated mandrel linear velocity command value The command value of the mandrel angular velocity is calculated:

[0079]

[0080] Specific implementation step S006: based on the designed mandrel angular velocity (7) control the operation of the coiler motor, and finally form a set of coiler tension control system.

[0081] In order to further verify the applicability of the method of the present application, we perform a comparative experiment using only the proportional-integral control method of the cascade and the method of the present application. In the experiment, we design two scenarios:

[0082] Scenario one: the plate strip forward offset S=0.005(m);

[0083] Scenario two: the plate strip forward offset S=0.01(m).

[0084] Figure 3 The tension change graph for scenario one is shown in Figure 1;The tension change graph for scenario two is shown in Figure 2. Figure 4

[0085] The above merely describes preferred specific embodiments of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims. The components and structures not described in detail in the embodiments are the components and structures commonly used in the industry or common means, which are not described here.

Claims

1. A strip slippage under coiler tension control method characterized by, The method comprises the following steps: S001: establishing a tension equation and a tension control model of the coiler; S002: establishing a dynamic estimator of the strip slip term to obtain an estimated value of the strip slip term; S003: designing a mandrel linear velocity active compensation module for the strip slip term; Since The unknown strip slip amount S and the unknown strip slip amount influence coefficient a are contained in the equation (1). Therefore, the known information part of the equation (1) is used to calculate the unknown strip slip amount S and the unknown strip slip amount influence coefficient a. A tension control model is established as follows: wherein is the unknown strip slip term in the tension equation; S004: designing a mandrel linear velocity set value under a zero slip condition based on a proportional feedback method; wherein is the strip tension estimate given by the dynamic estimator at time t, is the unknown strip slip term estimate given by the dynamic estimator at time t, li e R is a gain parameter 1 of the dynamic estimator of the strip slip term, and l2 e R is a gain parameter 2 of the dynamic estimator of the strip slip term. S005: calculating a mandrel angular velocity command value using the mandrel linear velocity command value; S006: controlling the coiler motor to operate based on the designed mandrel angular velocity command value. wherein Vt is the core linear velocity command value at time t 2u Vt(t) is the core linear velocity setting value at time t with the strip zero slip amount, Active compensation for unknown strip slip terms is achieved; ​ ​ where T r (t) is the tension set value at time t, k p is the proportional gain coefficient, combining equation (4) and equation (5), the spindle linear velocity command value is obtained: ​ Utilizing a mandrel linear velocity command value Computing a mandrel angular velocity command value; using the calculated mandrel linear velocity command value calculating a mandrel angular velocity command value wherein is the angular velocity command value of the mandrel at time t, r2∈R is the radius of the band. ​

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