A continuous tube winding tension control method with self-adaptive speed regulation of a mandrel

Abstract

The application provides a continuous tube coiling tension control method with adaptive speed regulation of a mandrel; the method comprises the following steps: step 1, establishing an equation that the continuous tube tension satisfies; step 2, establishing an expected continuous tube tension regulation system; step 3, establishing an online estimator of a forward offset proportional coefficient value; and step 4, designing a mandrel linear speed adaptive speed regulation method with active compensation of the continuous tube forward offset proportional coefficient. The application realizes active compensation of the mandrel linear speed for the continuous tube forward offset proportional coefficient by establishing the online estimator of the forward offset proportional coefficient value, obtaining the forward offset proportional coefficient estimation value in real time, and improving the tension regulation precision under the continuous tube forward offset condition. In the mandrel linear speed regulation method, the application introduces active compensation for the pinch device linear speed offset condition and a continuous tube tension feedback regulation part, and improves the stability and control precision of the tension regulation system.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of continuous pipe coiling tension control method design; in particular to a kind of continuous pipe coiling tension control method of mandrel self-adaptive speed regulation. BACKGROUND

[0002] Continuous pipe is also called flexible pipe, flexible pipe or coil pipe, which is a new generation of pipe material in petroleum engineering. It uses high-frequency induction welding technology to continuously form and weld several kilometers of strip steel, continuously produces in production line and winds in reel according to certain length for use. The length of single rod is generally 2000-9000m. The coiling process of continuous pipe is a key link in its production and processing process, and the core is the stable control of coiling tension. In the coiling process, by adjusting the mandrel linear velocity, a certain difference between the mandrel linear velocity and the pinch device linear velocity is generated, and then the continuous pipe will be deformed moderately to form stable tension. Therefore, the key problem of continuous pipe coiling tension stable control is the mandrel speed regulation problem.

[0003] In actual coiling process, the continuous pipe at pinch device will occur forward offset phenomenon, which will affect the tension stable control. Although the forward offset amount of continuous pipe can be obtained through engineering calibration, the influence value of the offset amount on the proportional coefficient of tension is unmeasurable and unobtainable. In the mandrel speed regulation method of proportional-integral feedback currently used in large quantities, the influence of unknown forward offset proportional coefficient is not considered, which leads to the failure to maintain high-precision tension control result. For the unmeasurable and unobtainable proportional coefficient of continuous pipe forward offset amount, how to design a new type of mandrel speed regulation method to realize the stable control of continuous pipe coiling tension and improve the precision of tension regulation is an actual engineering problem to be solved. SUMMARY

[0004] The present application provides a mandrel self-adaptive speed regulation continuous pipe coiling tension control method. In the present application, the continuous pipe will produce forward offset phenomenon in the coiling process, and the proportional coefficient value of the offset amount to tension is unknown, which leads to the decrease of tension control precision in the coiling process. The present application obtains the proportional coefficient estimation value of continuous pipe forward offset amount through the estimator of proportional coefficient value of continuous pipe forward offset amount. Further, the expected continuous pipe tension regulation system is constructed, the mandrel linear velocity self-adaptive speed regulation method with active compensation for the proportional coefficient of continuous pipe forward offset amount is improved, and the tension control precision under the condition of unknown proportional coefficient value of continuous pipe forward offset amount is improved. In the mandrel linear velocity self-adaptive speed regulation method, there are three parts: active compensation for the proportional coefficient of continuous pipe forward offset amount, active compensation for the linear velocity offset of pinch device, and expected continuous pipe tension feedback regulation.

[0005] The present application is realized by the following technical solutions:

[0006] The application relates to a continuous tube winding tension control method with adaptive speed regulation of a mandrel, comprising the following steps:

[0007] Step 1: establishing a continuous tube tension satisfying equation;

[0008] Step 2: establishing a desired continuous tube tension regulation system;

[0009] Step 3: establishing an online estimator of a forward offset proportional coefficient value;

[0010] Step 4: designing a mandrel linear speed adaptive speed regulation method with active compensation of a continuous tube forward offset proportional coefficient.

[0011] Preferably, in step 1, the continuous tube tension satisfying equation is as follows in equation (1):

[0012]

[0013] Wherein, F (t) is the tension size of the continuous tube at time t, v1 (t) is the pinch device linear speed size at time t, v2 (t) is the mandrel linear speed size at time t, S is the cross-sectional area of the continuous tube, K is the elastic coefficient of the continuous tube, L is the distance from the pinch device to the mandrel, P is the forward offset of the continuous tube transportation process, and M is the unmeasurable continuous tube forward offset proportional coefficient value.

[0014] Preferably, in step 2, the desired continuous tube tension regulation system is as follows in equation (2):

[0015]

[0016] Wherein, F p (t) is the desired tension size of the continuous tube at time t, and k p is the desired continuous tube tension closed-loop regulation speed coefficient.

[0017] Preferably, in step 3, the online estimator of the forward offset proportional coefficient value is as follows in equation (3):

[0018]

[0019] Wherein, M is the forward offset proportional coefficient estimation value given by the estimator at time t, and γ is the gain adjustment parameter of the forward offset proportional coefficient value estimator.

[0020] Preferably, in step 4, the specific method of the mandrel linear speed adaptive speed regulation method with active compensation of the continuous tube forward offset proportional coefficient is:

[0021] According to the continuous pipe tension equation (1), the expected continuous pipe tension adjustment system obtained in equation (2), and the forward offset proportional coefficient estimate value at time t obtained in step (3), a mandrel linear velocity adaptive speed regulation method for active compensation of the continuous pipe forward offset proportional coefficient is designed, and the equation (4) is as follows:

[0022]

[0023] Wherein Active compensation of the continuous pipe forward offset proportional coefficient is realized, and (1+P)v1(t) realizes active compensation of the pinch device linear speed offset, The expected continuous pipe tension feedback adjustment part is realized.

[0024] In the above formula of the application, the symbols are explained as follows:

[0025] R: a set of all real numbers;

[0026] t: running time of the winding system, t∈[0,∞);

[0027] F(t): the tension size of the continuous pipe at time t, F(t)∈R;

[0028] v1(t): the pinch device linear speed size at time t, v1(t)∈R;

[0029] v2(t): the mandrel linear speed size at time t, v2(t)∈R;

[0030] S: cross-sectional area of the continuous pipe, S∈R;

[0031] K: elastic coefficient of the continuous pipe, K∈R;

[0032] L: distance from the pinch device to the mandrel, L∈R;

[0033] P: forward offset of the continuous pipe transportation process, P∈R;

[0034] M: unmeasurable continuous pipe forward offset proportional coefficient value, M∈R;

[0035] F p (t): expected tension size of the continuous pipe at time t, F p (t)∈R;

[0036] k p : expected continuous pipe tension closed-loop adjustment speed coefficient, k p ∈R;

[0037] an estimated value of the forward offset proportionality coefficient at time t given by the estimator, γ: gain adjustment parameter of the forward offset proportionality coefficient value estimator, γ∈R;

[0038] The present application considers the forward offset of the continuous tube at the pinch device, and designs an estimator of the forward offset proportionality coefficient value of the continuous tube, and further obtains an estimated value of the forward offset proportionality coefficient of the continuous tube. According to the expected continuous tube tension adjustment system, a mandrel speed adaptive speed regulation method for active compensation of the forward offset proportionality coefficient of the continuous tube is invented. In the mandrel speed adaptive speed regulation method, three parts are included: active compensation of the forward offset proportionality coefficient of the continuous tube, active compensation of the linear speed offset of the pinch device, and feedback adjustment of the expected continuous tube tension.

[0039] The present application has the following advantages:

[0040] (1) The present application establishes an online estimator of the forward offset proportionality coefficient value, obtains the estimated value of the forward offset proportionality coefficient in real time, realizes active compensation of the mandrel speed for the forward offset proportionality coefficient of the continuous tube, and improves the tension adjustment accuracy under the forward offset condition of the continuous tube.

[0041] (2) In the mandrel speed regulation method, the present application introduces active compensation of the linear speed offset of the pinch device and the continuous tube tension feedback adjustment part, and improves the stability and control accuracy of the tension adjustment system. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 is a flow chart of the method of the present application;

[0043] Figure 2 is a control structure diagram of the method of the present application;

[0044] Figure 3 is a continuous tube tension winding test device of the method of the present application;

[0045] Figure 4 is a continuous tube tension control result diagram of the method of the present application and the proportional-integral feedback method under scene one and scene two. DETAILED DESCRIPTION

[0046] The present application will be described in detail below with specific embodiments. It should be pointed out that the following implementation examples are only further descriptions of the present application, and the protection scope of the present application is not limited to the following examples.

[0047] Embodiment

[0048] The present embodiment relates to a continuous tube winding tension control method of mandrel adaptive speed regulation, seen from Figure 1 andFigure 2 as shown, comprising the following steps:

[0049] Step 1, establish the equation that the continuous pipe tension satisfies;

[0050] Step 2, establish the expected continuous pipe tension adjustment system;

[0051] Step 3, establish the online estimator of the forward offset proportional coefficient value;

[0052] Step 4, design the mandrel speed adaptive speed regulation method of the continuous pipe forward offset proportional coefficient active compensation.

[0053] The present application takes specific operation steps as an example to expand the description of the method of the present application, and the detailed steps are as follows:

[0054] The actual parameters of the winding system and the continuous pipe are: S = 550 ((mm) 2 ), K = 1.9 x 10 5 (N / (mm) 2 ), L = 12 (m), P = 0.005 (m), v1 = 8 (m / s), F p (t) = 9 x 10 5 (N), (N / s).

[0055] Step 1: Establish the equation that the continuous pipe tension satisfies, and use the actual parameters of the winding system and the continuous pipe to obtain the continuous pipe tension equation:

[0056]

[0057] Where M is the unmeasurable continuous pipe forward offset proportional coefficient value.

[0058] Step 2: Establish the expected continuous pipe tension adjustment system:

[0059]

[0060] Where the expected continuous pipe tension closed-loop adjustment speed coefficient k p = 2.8 is selected.

[0061] Step 3: Establish the online estimator of the forward offset proportional coefficient value:

[0062]

[0063] Where the gain adjustment parameter γ of the forward offset proportional coefficient value estimator is 8.

[0064] Step four: according to the continuous pipe tension equation obtained in the specific implementation step one, the expected continuous pipe tension adjusting system obtained in the specific implementation step two and the forward offset proportional coefficient estimation value at the time t obtained in the specific implementation step three The core shaft linear velocity adaptive speed regulation method with active compensation of the continuous pipe forward offset proportional coefficient is designed as follows:

[0065]

[0066] The core shaft linear velocity input into the core shaft motor system is designed as above, so that the tension control in the winding process is realized.

[0067] In order to further study the applicability of the method, a comparative experiment between the proportional-integral feedback control method and the method is further carried out.

[0068] Scene one: the continuous pipe forward offset proportional coefficient value M=0.0005;

[0069] Scene two: the continuous pipe forward offset proportional coefficient value M=0.005.

[0070] Figure 4 The continuous pipe tension adjusting results under scene one and scene two are given.

[0071] Since the continuous pipe forward offset proportional coefficient is unknown, and the forward offset proportional coefficients in scene one and scene two are different, the tension control response is slow and the initial transient control performance is poor under the proportional-integral feedback control method. The estimator of the continuous pipe forward offset proportional coefficient value is invented, the continuous pipe forward offset proportional coefficient estimation value is obtained in real time, and the core shaft linear velocity adaptive speed regulation method with active compensation of the continuous pipe forward offset proportional coefficient is designed. Figure 4 The control results in the above table show that the method can realize the fast tracking control of the tension under the unknown forward offset proportional coefficient, the transient tracking response is good, and the stable tracking error is small.

[0072] In order to test the applicability of the method, the experiment verification is carried out for the continuous pipe tension adjusting system, and the experimental equipment is shown in Figure 3 .

[0073] In summary, the online estimator of the forward offset proportional coefficient value is established, the forward offset proportional coefficient estimation value is obtained in real time, the active compensation of the core shaft linear velocity to the continuous pipe forward offset proportional coefficient is realized, and the tension adjusting precision under the continuous pipe forward offset condition is improved. The active compensation of the pinch device linear velocity offset and the continuous pipe tension feedback adjusting part are introduced in the core shaft linear velocity speed regulation method, and the stability and control precision of the tension adjusting system are improved.

[0074] The specific embodiments of the present application have been described. It is to be understood that the application is not limited to particular details of construction described since modifications and variations thereof can be made by those skilled in the art without departing from the spirit or scope of the application.

Claims

1. A method for controlling the coiled tube tension with mandrel adaptive speed regulation, characterized in that: The following steps are involved: Step 1, establish the equation satisfied by the coiled tubing tension; Step 2: Establishing a desired coiled tubing tension adjustment system; Step 3, establishing an online estimator of the forward offset proportional coefficient value; Step 4, designing a core axis speed adaptive speed control method that actively compensates for the coiled tubing forward offset proportional coefficient; In step 1, the equation satisfying the coiled tubing tension is established, and equation (1) is as follows: Where, F(t)∈R is the tension on the coiled tube at time t, v1(t)∈R is the linear velocity of the clamping and conveying equipment at time t, v2(t)∈R is the axis velocity of the mandrel at time t, S∈R is the cross-sectional area of ​​the coiled tube, K∈R is the elastic coefficient of the coiled tube, L∈R is the distance from the clamping and conveying equipment to the mandrel, P∈R is the forward deflection of the coiled tube during transportation, and M∈R is the proportional coefficient of the unmeasurable forward deflection of the coiled tube. In step 2, the desired coiled tubing tension adjustment system is established, and equation (2) is as follows: Among them F p (t)∈R is the expected tension of the coiled tube at time t, k p ∈R is the desired coiled tubing tension closed-loop adjustment speed coefficient; In step 3, the online estimator of the forward offset proportional coefficient value is established, and its equation (3) is as follows: in is the estimated value of the forward offset proportional coefficient at time t given by the estimator, and γ∈R is the gain adjustment parameter of the forward offset proportional coefficient value estimator; In step 4, the specific method of designing the core axis speed adaptive speed regulation method for active compensation of the coiled tubing forward offset proportional coefficient is as follows: According to the coiled tubing tension equation (1), the desired coiled tubing tension adjustment system obtained in equation (2), and the estimated value of the forward offset proportional coefficient at time t obtained in step (3), a core axis speed adaptive speed control method with active compensation of the coiled tubing forward offset proportional coefficient is designed, and its equation (4) is as follows: in Active compensation for the proportional coefficient of the forward offset of the coiled tubing is realized, and (1+P)v1(t) is used to actively compensate for the linear speed offset of the pinching and conveying equipment. Achieve the desired coiled tubing tension feedback adjustment part.

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