A simplified electronic back pressure closed loop control method

Abstract

The present invention provides a simplified electronic back pressure closed loop control method, which belongs to the field of back pressure control systems, and includes the following steps: obtaining the structure of the electronic back pressure control system and the initial fixed dimension value of the system; pre-calculating the system constant according to the initial fixed dimension value of the system; obtaining the angle of the cradle in the system, and calculating the dimension and angle variable values ​​in the system through the pre-calculated system constants; defining the intermediate variable values ​​of the system through the obtained dimension and angle variable values; obtaining the real-time weight of the bobbin and the cradle in the system, and calculating the back pressure control target output value in combination with the dimension and angle variable values, the intermediate variable values ​​and the back pressure given value; obtaining the feedback value of the force sensor in the system, and realizing the back pressure closed loop control through the closed loop controller according to the back pressure control target output value. The present invention avoids the use of inverse trigonometric functions in the real-time calculation process by defining some intermediate variables, and improves the operation speed of the control system.

Description

Technical Field

[0001] The invention relates to the technical field of back pressure control systems, and in particular to a simplified 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] An existing closed-loop control method for an electronic back pressure system can calculate the control amount in real time according to the set back pressure control target value, and obtain the actual control result of the back pressure control in real time according to the force sensor, thereby realizing closed-loop control of the back pressure. However, this method involves a large number of angle calculations and the use of inverse trigonometric functions in the real-time calculation process, which will affect the computing efficiency of the main chip, thereby slowing down the response speed of the system and affecting the overall performance of the system. Summary of the invention

[0004] In order to overcome the deficiencies of the prior art, the purpose of the present invention is to provide a simplified electronic back pressure closed-loop control method, which avoids the use of inverse trigonometric functions in the real-time calculation process by defining some intermediate variables, thereby improving the operation speed of the control system.

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

[0006] S1. Obtain the structure of the electronic back pressure control system and the initial fixed size value of the system;

[0007] S2. Precalculate system constants based on the initial fixed size value of the system;

[0008] S3, obtaining the cradle angle in the system, and calculating the size and angle variable values ​​in the system through the pre-calculated system constants;

[0009] S4. Define the intermediate variable value of the system through the obtained size and angle variable values;

[0010] S5. Obtain the real-time weight of the bobbin and the cradle in the system, and calculate the back pressure control target output value by combining the size and angle variable values, the intermediate variable value and the back pressure given value;

[0011] S6. Obtain the feedback value of the force sensor in the system, and control the target output value according to the back pressure to achieve back pressure closed-loop control through a closed-loop controller.

[0012] Preferably, in step S1, the initial fixed dimensional values ​​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.

[0013] Preferably, in step S2, the system constants are pre-calculated, and the calculation process is as follows:

[0014] The connecting line distance L5 between the roller support point and the cradle support point:

[0015]

[0016] The connecting line distance between the cradle fulcrum and the screw fulcrum is L9:

[0017]

[0018] The angle α1 between L5 and L3:

[0019] α1=arctan(L4L3);

[0020] The angle θ between L8 and L9:

[0021] θ = arctan(L7L8).

[0022] Preferably, in step S3, the cradle angle is measured by an angle sensor in the system, and the angle between the cradle and the line between the roller fulcrum and the cradle fulcrum is determined according to the line distance between the roller fulcrum and the cradle fulcrum and the horizontal distance between the roller fulcrum and the cradle fulcrum, and the distance between the roller fulcrum and the center point of the bobbin is calculated, and the calculation process is as follows:

[0023] The angle α2 between the cradle and the line connecting the roller support and the cradle support:

[0024] α2 = α - α1;

[0025] Among them, α is the cradle angle measured by the angle sensor, and α1 is the angle between the line between the roller fulcrum and the cradle fulcrum and the horizontal direction;

[0026] The distance between the roller support point and the center point of the yarn cone is L2:

[0027]

[0028] Among them, L1 is the length of the rocker arm on the cradle, and L5 is the distance between the roller fulcrum and the cradle fulcrum.

[0029] Preferably, in step S4, the intermediate variable values ​​of the system are defined by the obtained size and angle variable values, including:

[0030] H1=L1*cosα;

[0031] H2=L1*L5*sinα2L2;

[0032]

[0033] Among them, H1, H2, and H3 are all intermediate variable values ​​of the system.

[0034] Preferably, in step S5, the calculation process of the back pressure control target output value is:

[0035] F = (G*H1-N*H2)H3;

[0036] Among them, F is the target output value of back pressure control, G is the real-time weight of the bobbin and the cradle, which is obtained by real-time calculation during the winding process, and N is the given value of back pressure.

[0037] Preferably, in step S6, 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.

[0038] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0039] The present invention provides a simplified electronic back pressure closed-loop control method, which avoids the use of inverse trigonometric functions in a real-time calculation process by defining some intermediate variables, thereby improving the calculation speed of the control system. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] 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.

[0041] Figure 1 A flowchart provided for a simplified electronic back pressure closed-loop control method embodiment 1 of the present invention;

[0042] Figure 2 A structural schematic diagram of a simplified electronic back pressure closed-loop control method embodiment 1 of the present invention is provided. DETAILED DESCRIPTION

[0043] 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.

[0044] The purpose of the present invention is to provide a simplified electronic back pressure closed-loop control method, which avoids the use of inverse trigonometric functions in the real-time calculation process by defining some intermediate variables, thereby improving the calculation speed of the control system.

[0045] 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.

[0046] Example 1

[0047] like Figure 1 As shown, the present invention provides a simplified electronic back pressure closed-loop control method, comprising the following steps:

[0048] S1. Obtain the structure of the electronic back pressure control system and the initial fixed size value of the system;

[0049] S2. Precalculate system constants based on the initial fixed size value of the system;

[0050] S3, obtaining the cradle angle in the system, and calculating the size and angle variable values ​​in the system through the pre-calculated system constants;

[0051] S4. Define the intermediate variable value of the system through the obtained size and angle variable values;

[0052] S5. Obtain the real-time weight of the bobbin and the cradle in the system, and calculate the back pressure control target output value by combining the size and angle variable values, the intermediate variable value and the back pressure given value;

[0053] S6. Obtain the feedback value of the force sensor in the system, and control the target output value according to the back pressure to achieve back pressure closed-loop control through a closed-loop controller.

[0054] 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.

[0055] Based on the above, refer to Figure 2 , simplifying the electronic back pressure control system. The initial fixed size values ​​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.

[0056] According to the above content, this embodiment proposes a simplified electronic back pressure closed-loop control method, including:

[0057] (1) First precalculate the following system constants:

[0058] The connecting line distance L5 between the roller support point and the cradle support point:

[0059]

[0060] The connecting line distance between the cradle fulcrum and the screw fulcrum is L9:

[0061]

[0062] The angle α1 between L5 and L3:

[0063] α1=arctan(L4L3);

[0064] The angle θ between L8 and L9:

[0065] θ = arctan(L7L8).

[0066] (2) Based on the cradle angle α measured in real time by the angle sensor and the geometric relationship between the dimensional variables, the following dimensional variables are calculated:

[0067] The angle α2 between the cradle and the line connecting the roller support and the cradle support:

[0068] α2 = α - α1;

[0069] Among them, α is the cradle angle measured by the angle sensor, and α1 is the angle between the line between the roller fulcrum and the cradle fulcrum and the horizontal direction.

[0070] The distance between the roller support point and the center point of the yarn cone is L2:

[0071]

[0072] Among them, L1 is the length of the rocker arm on the cradle, and L5 is the distance between the roller fulcrum and the cradle fulcrum.

[0073] (3) In order to simplify the calculation process, the following intermediate variables are defined:

[0074] H1=L1*cosα;

[0075] H2=L1*L5*sinα2L2;

[0076]

[0077] Among them, H1, H2, and H3 are all intermediate variable values ​​of the system.

[0078] (4) 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. Finally, the back pressure control target output value F is calculated based on the various size variables, intermediate variables, back pressure set value N, and real-time weight G. The above variables satisfy the relationship:

[0079] F = (G*H1-N*H2)H3;

[0080] 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, thereby realizing electronic back pressure closed-loop control. The closed-loop controller forms used include but are not limited to P, PI, PD, PID, etc.

[0081] Therefore, by adopting the simplified electronic back pressure closed-loop control method mentioned above, by defining some intermediate variables, the use of inverse trigonometric functions in the real-time calculation process is avoided, thereby improving the calculation speed of the control system.

[0082] 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.

[0083] 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. A simplified electronic back pressure closed-loop control method, characterized in that: The following steps are involved: S1. Obtain the structure of the electronic back pressure control system and the initial fixed size value of the system; S2. Precalculate system constants based on the initial fixed size value of the system; S3, obtaining the cradle angle in the system, and calculating the size and angle variable values ​​in the system through the pre-calculated system constants; S4. Define the intermediate variable value of the system through the obtained size and angle variable values; In step S4, the intermediate variable values ​​of the system are defined by the obtained size and angle variable values, including: H1=L1*cosα; H2=L1*L5*sinα2 / L2; Among them, H1, H2, and H3 are all intermediate variable values ​​of the system, L1 is the length of the upper rocker arm of the cradle, α is the angle of the cradle measured by the angle sensor, L2 is the distance between the roller fulcrum and the center point of the bobbin, L5 is the distance between the roller fulcrum and the cradle fulcrum, α2 is the angle between the cradle and the roller fulcrum and the cradle fulcrum, L6 is the length of the lower rocker arm of the cradle, L9 is the distance between the cradle fulcrum and the screw fulcrum, θ is the angle between L8 and L9, and L8 is the horizontal distance between the cradle fulcrum and the screw fulcrum; S5. Obtain the real-time weight of the bobbin and the cradle in the system, and calculate the back pressure control target output value by combining the size and angle variable values, the intermediate variable value and the back pressure given value; S6. Obtain the feedback value of the force sensor in the system, and control the target output value according to the back pressure to achieve back pressure closed-loop control through a closed-loop controller.

2. A simplified electronic back pressure closed-loop control method according to claim 1, characterized in that: In step S1, the initial fixed dimension values ​​of the system include: roller radius r, empty tube 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.

3. A simplified electronic back pressure closed-loop control method according to claim 1 or 2, characterized in that: In step S2, the system constants are pre-calculated, and the calculation process is as follows: The connecting line distance L5 between the roller support point and the cradle support point: The connecting line distance between the cradle fulcrum and the screw fulcrum is L9: The angle α1 between L5 and L3: α1=arctan(L4 / L3); The angle θ between L8 and L9: θ = arctan(L7 / L8).

4. A simplified electronic back pressure closed-loop control method according to claim 1, characterized in that: In step S3, the angle of the cradle is measured by the angle sensor in the system, and the angle between the cradle and the line connecting the roller fulcrum and the cradle fulcrum is determined according to the distance between the roller fulcrum and the cradle fulcrum and the horizontal distance between the roller fulcrum and the cradle fulcrum, and the distance between the roller fulcrum and the center point of the bobbin is calculated. The calculation process is as follows: The angle α2 between the cradle and the line connecting the roller support and the cradle support: α2＝α-α1； Among them, α is the cradle angle measured by the angle sensor, and α1 is the angle between the line between the roller fulcrum and the cradle fulcrum and the horizontal direction; The distance between the roller support point and the center point of the yarn cone is L2: Among them, L1 is the length of the rocker arm on the cradle, and L5 is the distance between the roller fulcrum and the cradle fulcrum.

5. A simplified electronic back pressure closed-loop control method according to claim 1, characterized in that: In step S5, the calculation process of the back pressure control target output value is: F = (G*H1-N*H2) / H3; Among them, F is the target output value of back pressure control, G is the real-time weight of the bobbin and the cradle, which is obtained by real-time calculation during the winding process, and N is the given value of back pressure.

6. A simplified electronic back pressure closed-loop control method according to claim 1, characterized in that: In step S6, the back pressure control target output value F and the force sensor feedback value F are used. * , 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.

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