A method for electronic back pressure closed loop control

Abstract

The present invention provides an electronic back pressure closed-loop control method, which belongs to the field of back pressure control systems, including: determining the structure and fixed size of the electronic back pressure system, and pre-calculating its system constants; obtaining the angle of the cradle in the system or its incremental value, defining the size and angle variables in the system; calculating the yarn weight in the system or obtaining it from the upper computer of the system, defining the real-time weight of the yarn tube and the cradle in the system; calculating the back pressure closed-loop control target output value through the size variable and the real-time weight, combined with the back pressure control given value; obtaining the feedback value of the force sensor in the system, combined with the back pressure closed-loop control target output value, so as to realize the back pressure closed-loop control through a closed-loop controller. The present invention calculates the control amount in real time according to the set back pressure control target value, and obtains the actual control result of the back pressure control in real time according to the force sensor, thereby realizing the closed-loop control of the back pressure, and effectively improving the operation convenience, control accuracy and consistency of the control result of the back pressure control system.

Description

Technical Field

[0001] The present invention relates to the technical field of back pressure control systems, and in particular to an electronic back pressure closed-loop control method. Background Art

[0002] In the yarn winding system, back pressure control can adjust the contact force between the yarn bobbin and the friction roller (roller), thereby adjusting the winding density of the yarn to a certain extent, improving the forming and tightness of the yarn bobbin, which has significant advantages especially in some specific application scenarios.

[0003] However, traditional back pressure control systems are mostly based on open-loop control of mechanical structures, and control accuracy and consistency are difficult to guarantee. When the back pressure control target value needs to be changed, it is necessary to manually adjust the angle and tightness of the spring mechanism. This process needs to be done manually one by one, and the operation process also requires the assistance of other tools such as wrenches and spring scales, which requires a lot of manpower and is difficult to operate. In order to solve the above problems, some simple electronic back pressure control systems have been proposed in previous applications, thereby simplifying the problem of back pressure target value setting. However, their methods are also open-loop control strategies based on operating experience. Due to the lack of feedback, their control accuracy and control effect are not ideal. Summary of the invention

[0004] In order to overcome the shortcomings of the prior art, the purpose of the present invention is to provide an electronic backpressure closed-loop control method, which can calculate the control quantity in real time according to the set backpressure control target value, and obtain the actual control result of the backpressure control in real time according to the force sensor, thereby realizing closed-loop control of the backpressure, which can effectively improve the operating convenience, control accuracy and consistency of the control results of the backpressure control system.

[0005] To achieve the above object, the present invention provides the following solution: an electronic back pressure closed-loop control method, comprising the following steps:

[0006] S1. According to the electronic back pressure system, determine its system structure and fixed dimensions, and pre-calculate its system constants;

[0007] S2, obtaining the cradle angle or its incremental value in the system, and defining the size and angle variables in the system through pre-calculated system constants;

[0008] S3, calculate the yarn weight in the system or obtain it from the upper computer of the system, and define the real-time weight of the yarn tube and the cradle in the system;

[0009] S4. Calculate the target output value of the back pressure closed-loop control based on the calculated size variables and real-time variables and the back pressure control given value;

[0010] S5. Obtain the feedback value of the force sensor in the system, and apply it to the back pressure closed-loop control target output value to achieve back pressure closed-loop control through a closed-loop controller.

[0011] Preferably, in step S1, the fixed dimensions of the system include: roller radius r, empty cylinder radius R0, upper rocker arm length L1 of cradle, horizontal distance L3 between roller fulcrum and cradle fulcrum, vertical distance L4 between roller fulcrum and cradle fulcrum, lower rocker arm length L6 of cradle, vertical distance L7 between cradle fulcrum and screw fulcrum, horizontal distance L8 between cradle fulcrum and screw fulcrum.

[0012] Preferably, precalculation of system constants includes:

[0013] The distance between the roller support and the cradle support is L5:

[0014]

[0015] Distance between the fulcrum of the cradle and the fulcrum of the screw L9:

[0016]

[0017] The angle α1 between L5 and L3:

[0018] α1=arctan(L4 / L3);

[0019] The angle θ between L8 and L9:

[0020] θ = arctan(L7 / L8);

[0021] Angle α0 of the cradle in the empty cylinder state:

[0022]

[0023] Preferably, in step S2, according to the angle sensor in the system detecting the cradle angle or its incremental value in real time, calculating the size and angle variables in the system includes:

[0024] Angle α2 between the cradle and L5:

[0025] α2=α-α1 or α2=α0+Δα;

[0026] Among them, α is the cradle angle, Δα is the angle increment value;

[0027] The distance between the roller support point and the center point of the yarn cone is L2:

[0028]

[0029] The angle β between L2 and the horizontal direction:

[0030] β=arcsin((L1*sinα-L4) / L2) or β=arcsin(L1*sinα2 / L2)-α1;

[0031] The angle θ1 between the screw and L9:

[0032] θ1=arccot[(L9 / L6+cos(α+θ)) / sin(α+θ)];

[0033] Angle θ2 between the screw and the horizontal direction:

[0034] θ2=θ-θ1.

[0035] Preferably, in step S3, the real-time weight of the bobbin and the cradle in the system is defined as:

[0036] G = G1 + G2;

[0037] Among them, G is the real-time weight of the bobbin and the cradle, G1 is the inherent weight of the system, and G2 is the yarn weight.

[0038] Preferably, the inherent weight G1 of the system includes but is not limited to the weight of the tube and the weight of the cradle, and the yarn weight G2 is calculated in real time during the winding process or converted according to the current diameter of the yarn tube.

[0039] Preferably, in step S4, the calculation process of the back pressure closed-loop control target output value is:

[0040]

[0041] Among them, F is the target output value of back pressure closed-loop control, L1 is the length of the upper rocker arm of the cradle, G is the real-time weight of the yarn tube and the cradle, N is the given value of back pressure, α is the cradle angle, β is the angle between L2 and the horizontal direction, L6 is the length of the lower rocker arm of the cradle, and θ2 is the angle between the screw and the horizontal direction.

[0042] Preferably, according to the back pressure control target output value F and the force sensor feedback value F * , through the tracking adjustment of the closed-loop controller, the closed-loop control of the back pressure set value N is realized, and the closed-loop controller forms adopted include but are not limited to P, PI, PD, and PID.

[0043] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0044] The present invention provides an electronic backpressure closed-loop control method, which can calculate the control quantity in real time according to the set backpressure control target value, and obtain the actual control result of the backpressure control in real time according to the force measuring sensor, thereby realizing closed-loop control of the backpressure, which can effectively improve the operating convenience, control accuracy and consistency of the control results of the backpressure control system. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0046] Figure 1 A flow chart provided for an electronic back pressure closed-loop control method of the present invention;

[0047] Figure 2 This is a structural schematic diagram of the electronic back pressure closed-loop control method provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0048] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] The purpose of the present invention is to provide an electronic backpressure closed-loop control method, which can calculate the control quantity in real time according to the set backpressure control target value, and obtain the actual control result of the backpressure control in real time according to the force sensor, thereby realizing closed-loop control of the backpressure, which can effectively improve the operating convenience, control accuracy and consistency of the control results of the backpressure control system.

[0050] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0051] Example 1

[0052] like Figure 1 As shown, the present invention provides an electronic back pressure closed-loop control method, comprising the following steps:

[0053] S1. According to the electronic back pressure system, determine its system structure and fixed dimensions, and pre-calculate its system constants;

[0054] S2, obtaining the cradle angle or its incremental value in the system, and defining the size and angle variables in the system through pre-calculated system constants;

[0055] S3, calculate the yarn weight in the system or obtain it from the upper computer of the system, and define the real-time weight of the yarn tube and the cradle in the system;

[0056] S4. Calculate the target output value of the back pressure closed-loop control based on the calculated size variables and real-time variables and the back pressure control given value;

[0057] S5. Obtain the feedback value of the force sensor in the system, and apply it to the back pressure closed-loop control target output value, so as to realize the back pressure closed-loop control through the closed-loop controller.

[0058] In this embodiment, the electronic back pressure closed-loop control method provided is applicable to the electronic back pressure control system, which adds a screw motor and a slider mechanism to the traditional precision winding system to control the cradle action; and a force sensor to detect the actual back pressure on the bobbin in real time, so as to perform closed-loop feedback control of the electronic back pressure system. In addition, the angle sensor installed on the cradle of the traditional precision winding mechanism also acts on the electronic back pressure control system, providing the cradle angle information in real time for the system control method.

[0059] Based on the above, refer to Figure 2 , simplifying the electronic back pressure control system. The fixed dimensions of the system include: roller radius r, empty tube radius R0, upper rocker arm length L1, horizontal distance between roller fulcrum and cradle fulcrum L3, vertical distance between roller fulcrum and cradle fulcrum L4, lower rocker arm length L6, vertical distance between cradle fulcrum and screw fulcrum L7, horizontal distance between cradle fulcrum and screw fulcrum L8; the input variables of the system include: back pressure set value N, real-time weight of bobbin and cradle G, cradle angle α, force sensor feedback value F * ; The output variables of the system include: back pressure control target output value F.

[0060] To simplify the backpressure calculation, the following system constants are predefined first:

[0061] The distance between the roller support and the cradle support is L5:

[0062]

[0063] Distance between the fulcrum of the cradle and the fulcrum of the screw L9:

[0064]

[0065] The angle α1 between L5 and L3:

[0066] α1=arctan(L4 / L3);

[0067] The angle θ between L8 and L9:

[0068] θ = arctan(L7 / L8).

[0069] Furthermore, according to the cradle angle α measured in real time by the angle sensor in the system and the geometric relationship between the dimensional variables, the following dimensional variables can be calculated:

[0070] Angle α2 between the cradle and L5:

[0071] α2 = α - α1;

[0072] Among them, α is the cradle angle;

[0073] The distance between the roller support point and the center point of the yarn cone is L2:

[0074]

[0075] The angle β between L2 and the horizontal direction:

[0076] β=arcsin((L1*sinα-L4) / L2) or β=arcsin(L1*sinα2 / L2)-α1;

[0077] The angle θ1 between the screw and L9:

[0078] θ1=arccot[(L9 / L6+cos(α+θ)) / sin(α+θ)];

[0079] Angle θ2 between the screw and the horizontal direction:

[0080] θ2=θ-θ1.

[0081] At the same time, in order to calculate the back pressure control target output value F, it is also necessary to obtain the current weight G of the bobbin and the cradle in real time. For the convenience of calculation, G is divided into two parts, G1 and G2, where G1 represents the fixed part, which is the inherent weight of the system (including the weight of the tube, the weight of the cradle, etc.), which can be measured in advance, and G2 represents the variable part, which is mainly the weight of the yarn, which can be calculated in real time during the winding process, or converted by the current diameter of the bobbin, so that G=G1+G2 is finally calculated.

[0082] Finally, the back pressure control target output value F is calculated based on the various dimensional variables, the back pressure given value N, and the real-time weight G. According to the force analysis, the above variables satisfy the following relationship:

[0083]

[0084] Then, according to the back pressure control target output value F and the force sensor feedback value F * Through the closed-loop controller, the back pressure set value N can be tracked and adjusted to realize electronic back pressure closed-loop control. The closed-loop controller forms used include but are not limited to P, PI, PD, PID, etc.

[0085] In summary, the specific steps of the electronic back pressure control method are as follows:

[0086] (1) Determine the system structure and initial parameters r, L1, L3, L4, L6, L7, L8, G1;

[0087] (2) Pre-calculate system constants L5, L9, α1, θ:

[0088]

[0089]

[0090] α1=arctan(L4 / L3);

[0091] θ = arctan(L7 / L8);

[0092] (3) Calculate the following dimensions and angle variables in real time based on the angle sensor α:

[0093] α2 = α - α1;

[0094]

[0095] β=arcsin((L1*sinα-L4) / L2) or β=arcsin(L1*sinα2 / L2)-α1;

[0096] θ1=arccot[(L9 / L6+cos(α+θ)) / sin(α+θ)];

[0097] θ2=θ-θ1.

[0098] (4) Calculate the yarn weight G2 in real time or obtain it from the host computer, and calculate G: G = G1 + G2;

[0099] (5) According to the back pressure control given value N, calculate the back pressure closed loop control target output value:

[0100]

[0101] (6) Obtain the feedback value F of the force sensor in the system * , and applied to the back pressure closed-loop control target output value F to achieve back pressure closed-loop control through a closed-loop controller.

[0102] In addition, in some application scenarios, the angle sensor does not provide the absolute value α of the cradle angle, but the angle increment value Δα, so the above method needs to be adjusted:

[0103] The empty cylinder radius R0 needs to be added to the system structure parameters;

[0104] In the pre-calculation constant stage, add the calculation of the angle α0 when the cradle is in the empty cylinder state:

[0105]

[0106] The values ​​of α and α2 are obtained by calculation of α2=α0+Δα and α=α1+α2.

[0107] Therefore, the specific steps of the electronic back pressure control method are adjusted as follows:

[0108] (1) Determine the system structure and initial parameters r, R0, L1, L3, L4, L6, L7, L8, G1;

[0109] (2) Pre-calculate system constants L5, L9, α1, θ, α0:

[0110]

[0111]

[0112] α1=arctan(L4 / L3);

[0113] θ = arctan(L7 / L8);

[0114]

[0115] (3) Calculate the following dimensions and angle variables in real time based on the angle sensor increment value Δα:

[0116] α2=α0+Δα;

[0117] α=α1+α2;

[0118]

[0119] β=arcsin((L1*sinα-L4) / L2) or β=arcsin(L1*sinα2 / L2)-α1;

[0120] θ1=arccot[(L9 / L6+cos(α+θ)) / sin(α+θ)];

[0121] θ2=θ-θ1.

[0122] (4) Calculate the yarn weight G2 in real time or obtain it from the host computer, and calculate G: G = G1 + G2;

[0123] (5) According to the back pressure control given value N, calculate the back pressure closed loop control target output value:

[0124]

[0125] (6) Obtain the feedback value F of the force sensor in the system * , and applied to the back pressure closed-loop control target output value F to achieve back pressure closed-loop control through a closed-loop controller.

[0126] Therefore, by adopting the above-mentioned electronic back pressure closed-loop control method, the control quantity can be calculated in real time according to the set back pressure control target value, and the actual control result of the back pressure control can be obtained in real time according to the force sensor, thereby realizing closed-loop control of the back pressure, which can effectively improve the operating convenience, control accuracy and consistency of the control results of the back pressure control system.

[0127] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0128] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. An electronic back pressure closed-loop control method, characterized in that: The following steps are involved: S1. According to the electronic back pressure system, determine its system structure and fixed dimensions, and pre-calculate its system constants; the fixed dimensions of the system include: roller radius r, empty tube radius R0, cradle upper rocker arm length L1, horizontal distance between roller fulcrum and cradle fulcrum L3, vertical distance between roller fulcrum and cradle fulcrum L4, cradle lower rocker arm length L6, vertical distance between cradle fulcrum and screw fulcrum L7, horizontal distance between cradle fulcrum and screw fulcrum L8; S2, obtaining the cradle angle or its incremental value in the system, and defining the size and angle variables in the system through pre-calculated system constants; S3, calculate the yarn weight in the system or obtain it from the upper computer of the system, and define the real-time weight of the yarn tube and the cradle in the system; S4. According to the calculated size variables and real-time variables, combined with the back pressure control given value, the back pressure closed-loop control target output value is calculated; the calculation process of the back pressure closed-loop control target output value is: Among them, F is the target output value of back pressure closed-loop control, L1 is the length of the upper rocker arm of the cradle, G is the real-time weight of the bobbin and the cradle, N is the given value of back pressure, α is the angle of the cradle, β is the angle between L2 and the horizontal direction, where L2 is the distance between the roller support point and the center point of the bobbin; L6 is the length of the lower rocker arm of the cradle, and θ2 is the angle between the screw and the horizontal direction; S5. Obtain the feedback value of the force sensor in the system, and apply it to the back pressure closed-loop control target output value to achieve back pressure closed-loop control through a closed-loop controller.

2. The electronic back pressure closed-loop control method according to claim 1, characterized in that: Precalculation of system constants includes: The distance between the roller support and the cradle support is L5: Distance between the fulcrum of the cradle and the fulcrum of the screw L9: The angle α1 between L5 and L3: α1=arctan(L4 / L3); The angle θ between L8 and L9: θ = arctan(L7 / L8); Angle α0 of the cradle in the empty cylinder state:

3. The electronic back pressure closed-loop control method according to claim 2, characterized in that: In step S2, according to the angle sensor in the system detecting the cradle angle or its incremental value in real time, the size and angle variables in the system are calculated, including: Angle α2 between the cradle and L5: α2=α-α1 or α2=α0+Δα; Among them, α is the cradle angle, Δα is the angle increment value; The distance between the roller support point and the center point of the yarn cone is L2: The angle β between L2 and the horizontal direction: β=arcsin((L1*sinα-L4) / L2) or β=arcsin(L1*sinα2 / L2)-α1; The angle θ1 between the screw and L9: θ1=arccot[(L9 / L6+cos(α+θ)) / sin(α+θ)]; Angle θ2 between the screw and the horizontal direction: θ2=θ-θ1.

4. The electronic back pressure closed-loop control method according to claim 1, characterized in that: In step S3, the real-time weight of the bobbin and the cradle in the system is defined as: G = G1 + G2; Among them, G is the real-time weight of the bobbin and the cradle, G1 is the inherent weight of the system, and G2 is the yarn weight.

5. The electronic back pressure closed-loop control method according to claim 4, characterized in that: The inherent weight G1 of the system includes but is not limited to the weight of the yarn tube and the weight of the cradle. The yarn weight G2 is calculated in real time during the winding process or converted according to the current diameter of the yarn tube.

6. The electronic back pressure closed-loop control method according to claim 1, characterized in that: According to the back pressure control target output value F and the force sensor feedback value F * , through the tracking adjustment of the closed-loop controller, the closed-loop control of the back pressure set value N is realized, and the closed-loop controller forms adopted include but are not limited to P, PI, PD, and PID.

Images