Contact back pressure dynamic control device and method based on cone yarn integral calculation model

Abstract

The invention discloses a contact back pressure dynamic control device and method based on a cone yarn integral calculation model. The contact back pressure dynamic control device comprises a rotating arm, a friction roller, a torsion rotating shaft, a base and a torque control assembly, the friction roller is rotationally connected to the base; the torsion rotating shaft is rotationally connected to the base through a bearing frame. The rotating arm is U-shaped and comprises a connecting beam and two side arms which are parallel to each other; the connecting beam is fixed with the torsion rotating shaft; a spool dismounting structure is arranged between the outer ends of the two side arms; by means of the mode of dynamically adjusting the output torque of the motor, contact back pressure fluctuation caused by increase of the weight of cone yarn is dynamically compensated; compared with a traditional mechanical spring contact back pressure balancing method, the method has the advantages that the contact back pressure of cone yarn winding forming can be accurately controlled to be maintained at a preset constant value in real time, it is guaranteed that yarn is evenly stretched and transmitted, and therefore the stability and uniformity of yarn winding are guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of doubling machine production, and in particular to a contact back pressure dynamic control device and method based on a bobbin integral calculation model. Background Art

[0002] The contact back pressure is one of the key factors affecting winding formation. Its function is to balance the gradually increasing deadweight of the bobbin to obtain a more uniform yarn tension. As the winding process proceeds, the bobbin contains more and more yarns, and the winding diameter increases accordingly. The increase in its own weight will increase the internal tension of the yarn during the winding process. In order to ensure that the fibers can be well and closely arranged during the winding process, thereby forming high-quality molding, a series of measures need to be taken. In addition to accurately controlling the tension of the fiber filaments and ensuring the accuracy of the forming angle during the winding process, special attention should be paid to the contact back pressure between the friction and the winding. This is because the constancy of the contact back pressure is crucial for the uniform distribution and close arrangement of the fibers, which directly affects the traction and transfer process of the yarn, thereby affecting the stability of the spinning process and the yarn quality. Appropriately reducing the contact back pressure between the bobbin and the active roller can ensure that the yarn is evenly stretched and transferred, thereby ensuring the stability and uniformity of the yarn.

[0003] During the research and practice of this method, we found that when the doubling machine is working, the weight of the bobbin gradually increases to balance the yarn tension. As the winding process progresses, the bobbin contains more and more yarn, and the winding diameter increases accordingly. The increase in its own weight will increase the internal tension of the yarn during the winding process. This will cause the contact back pressure generated by the bobbin pressing on the winding roller to increase. Appropriate and constant contact back pressure between the bobbin and the active roller can ensure that the yarn is evenly stretched and transferred, thereby ensuring the stability and uniformity of the yarn.

[0004] Since the contact back pressure generated by the winding roller when the bobbin is wound is not linear, the traditional method using mechanical springs cannot balance the contact back pressure well. Now, the support force of the rotating arm is calculated in real time by combining the tension of the yarn, the gravity of the bobbin and the contact back pressure of the bobbin on the friction roller. Then the motor drives the rotating arm, and the bobbin is lifted accordingly. In this way, the contact back pressure on the friction roller is balanced and kept at a constant value. Summary of the invention

[0005] In view of the defects of the prior art, the purpose of the present invention is to provide a contact back pressure dynamic control device and method based on a bobbin yarn integral calculation model, which can measure and calculate the net weight change of the bobbin yarn in real time, and dynamically compensate for the contact back pressure through motor torque adjustment.

[0006] In the first aspect, the present invention provides a contact back pressure dynamic control device based on a bobbin integral calculation model, which includes a rotating arm, a friction roller, a torsion shaft, a base and a torque control assembly; the friction roller is rotatably connected to the base; the torsion shaft is rotatably connected to the base through a support frame; the rotating arm is U-shaped, including a connecting beam, and two parallel side arms; the connecting beam is fixed to the torsion shaft; a bobbin disassembly and assembly structure is arranged between the outer ends of the two side arms; the axis of the bobbin disassembly and assembly structure, the axis of the friction roller and the axis of the torsion shaft are parallel to each other; the bobbin disassembly and assembly structure is located above the friction roller; the torque control assembly includes a transmission assembly and a motor; the motor is mounted on the base; the output shaft of the motor is connected to the torsion shaft through the transmission assembly; the contour acquisition assembly acquires the axial cross-sectional contour of the bobbin through a laser ranging sensor.

[0007] During the yarn winding process, the yarn installed on the yarn bobbin disassembly and assembly structure is squeezed from top to bottom on the friction roller; as the amount of yarn wound on the yarn bobbin increases, the weight of the yarn bobbin increases; the torque output by the motor gradually increases, so that the contact back pressure between the yarn bobbin and the friction roller is controlled within a preset range.

[0008] Preferably, it also includes a contour acquisition component; the contour acquisition component includes a radial laser ranging sensor, a first axial laser ranging sensor, a second axial laser ranging sensor, a front linear slide, a first side linear slide and a second side linear slide; the front linear slide is installed on the connecting beam of the rotating arm; the first side linear slide and the second side linear slide are respectively installed on the two side arms of the rotating arm; the radial laser ranging sensor, the first axial laser ranging sensor and the second axial laser ranging sensor are respectively installed on the sliders of the front linear slide, the first side linear slide and the second side linear slide; the moving direction of the radial laser ranging sensor is parallel to the axis of the yarn bobbin disassembly and assembly structure; the moving directions of the first axial laser ranging sensor and the second axial laser ranging sensor are both perpendicular to the axis of the yarn bobbin disassembly and assembly structure.

[0009] Preferably, the side arm is provided with a clearance groove arranged along the length direction of the side arm; the first side linear slide and the second side linear slide are respectively installed in the clearance grooves of the two side arms; the moving paths of the detection points of the first axial laser ranging sensor and the second axial laser ranging sensor are perpendicular to the axis of the yarn tube disassembly and assembly structure; the laser emission direction of the radial laser ranging sensor is perpendicular to the axis of the torque shaft.

[0010] Preferably, the transmission assembly includes a synchronous belt, a first pulley, and a second pulley; the motor is mounted on a base; the first pulley and the second pulley are respectively fixed on the torque shaft and the output shaft of the motor; the first pulley and the second pulley are connected via a synchronous belt drive.

[0011] Preferably, two friction brackets which are spaced apart and aligned with each other are fixed on the friction bracket; two ends of the friction roller and the two friction brackets respectively form a rotating pair.

[0012] In a second aspect, the present invention provides a contact back pressure dynamic control method, which uses the aforementioned contact back pressure dynamic control device based on the package yarn integral calculation model; the contact back pressure dynamic control method comprises the following steps:

[0013] Step 1: Install the yarn tube on the yarn tube disassembly and assembly structure; and make the yarn tube rest against the top of the friction roller; the external servo motor drives the friction roller to rotate, driving the yarn tube to rotate, and winding the yarn.

[0014] Step 2: yarn bobbin winding volume measurement stage;

[0015] 2-1. During the rotation of the yarn bobbin, the three laser ranging sensors scan along their own moving trajectories to obtain data points; the three laser ranging sensors project the measured data points into the same plane coordinate system according to their own positions to obtain the bobbin point set corresponding to the bobbin contour; the bobbin point set includes three subsets; the points in the three subsets come from the three laser ranging sensors respectively.

[0016] 2-2. The three subsets were fitted separately using the nonlinear least squares method to obtain the two end profile curves and the side profile curve of the bobbin yarn.

[0017] 2-3. Connect the ends of the two end face profile curves away from the side face profile curve with a straight line to obtain the bobbin generatrix; the side face profile curve, the two end face profile curves and the bobbin generatrix together form the bobbin half-section profile; calculate the bobbin volume V through the bobbin half-section profile.

[0018] 2-4. Calculate the net weight G of the package s as follows:

[0019] G s =V·γ

[0020] Among them, the winding density of the package yarn is γ.

[0021] Step 3: According to the net weight G of the bobbin s , adjust the output torque of the motor so that the contact back pressure between the package yarn and the friction roller is controlled within a preset range.

[0022] Preferably, the expression of the package volume V is:

[0023]

[0024] Among them, x is the axial coordinate of the half-section profile of the bobbin yarn; z is the radial coordinate of the half-section profile of the bobbin yarn; L3 is the function of the bobbin generatrix; L1 is the function of the side profile curve; L2 and L3 are functions of the two end face profile curves; a and b are the radial coordinates of the intersection of the side profile curve and the two end face profile curves respectively; c and d are the radial coordinates of the intersection of the bobbin generatrix and the two end face profile curves respectively.

[0025] As a preferred method, adjust the output torque T of the motor s The expression is as follows:

[0026] T s =[G b ·L b ·cosβ+(G s +G t +G c )·L·cosβ-F N ·L·cos(β-α)] / i

[0027] Among them, F N To build the contact back pressure between the package yarn and the friction roller; G b is the gravity of the rotating arm; G s G is the net weight of the yarn; t is the weight of the yarn cone; G c is the weight of the bobbin disassembly and assembly structure; β is the inclination angle of the force arm of the rotating arm on the bobbin relative to the horizontal plane; α is the support angle of the friction roller on the bobbin; L is the center distance between the torsion shaft and the bobbin; L b It is the distance from the center of gravity of the rotating arm to the axis of the torque shaft.

[0028] The tilt angle β is obtained by detecting the rotation angle of the torque shaft through an encoder.

[0029] The relationship between the support angle α and the inclination angle β is as follows:

[0030]

[0031] Among them, Δx is the horizontal distance between the axis of the bobbin yarn and the axis of the friction roller when the rotating arm is in the horizontal state; Δh is the vertical distance between the axis of the bobbin yarn and the axis of the friction roller when the rotating arm is in the horizontal state.

[0032] As a preferred method, adjust the output torque T of the motor s The expression is as follows:

[0033] T s =[G b ·L b ·cosβ+(G s +G t +G c -F N)·L·cosβ] / i

[0034] Among them, F N To build the contact back pressure between the package yarn and the friction roller; G b is the gravity of the rotating arm; G s G is the net weight of the yarn; t is the weight of the yarn cone; G c is the weight of the bobbin disassembly and assembly structure; β is the inclination angle of the force arm of the rotating arm on the bobbin relative to the horizontal plane; L is the center distance between the torsion shaft and the bobbin; L b It is the distance from the center of gravity of the rotating arm to the axis of the torque shaft.

[0035] The tilt angle β is obtained by detecting the rotation angle of the torque shaft through an encoder.

[0036] As a preferred method, adjust the output torque T of the motor s The expression is as follows:

[0037] T s = k[G b ·L b +(G s +G t +G c -F N )·L] / i

[0038] Among them, F N To build the contact back pressure between the package yarn and the friction roller; G b is the gravity of the rotating arm; G s G is the net weight of the yarn; t is the weight of the yarn cone; G c is the weight of the bobbin disassembly and assembly structure; L is the center distance between the torque shaft and the bobbin; L b is the distance from the center of gravity of the rotating arm to the axis of the torque shaft; k is the correction coefficient.

[0039] It can be seen from the above technical solution that the beneficial effects of the present invention are:

[0040] 1. The present invention dynamically compensates for the contact back pressure fluctuation caused by the increase of the weight of the bobbin yarn by dynamically adjusting the output torque of the motor; compared with the traditional mechanical spring contact back pressure balancing method, the present invention can accurately and in real time control the contact back pressure of the bobbin yarn winding to maintain it at a preset constant value, ensuring that the yarn is evenly stretched and transferred, thereby ensuring the stability and uniformity of the yarn winding.

[0041] 2. The present invention uses a laser guide rail sensor to scan the outer circumferential side and both end faces of the bobbin yarn to fit the volume of the bobbin yarn, thereby accurately controlling the winding process of the bobbin yarn and converting the net weight change of the bobbin yarn to provide a basis for the change of the motor output torque; the non-contact measurement method can obtain the real-time and accurate volume and weight of the bobbin yarn while ensuring that the normal winding of the bobbin yarn is not affected. In addition, the present invention realizes the noise reduction processing of the original data obtained by the laser guide rail sensor based on the noise characteristics, uses the least squares fitting method and the rotating surface equation to establish the mathematical model of the bobbin yarn after the bobbin yarn is removed, takes into account the texture and concave-convex of the bobbin yarn surface, realizes the accurate measurement of its appearance characteristics, and obtains the volume value of the bobbin yarn by the integral method.

[0042] 3. The present invention uses a motor to balance the contact back pressure of the friction roller through the supporting force of the rotating arm, which is more accurate than using a motor to balance the contact back pressure of the friction roller by measuring the contact back pressure through a pressure plate. The reason is that when the winding machine is working, the rotation speed of the friction roller is too fast, the mechanical temperature is high, and the environmental noise and vibration are large. However, the piezoelectric pressure sensor has poor linearity, is easily affected by temperature, humidity and vibration, has poor stability, has a short life in harsh environments, and requires frequent replacement. Therefore, it is difficult to accurately measure the contact back pressure of the bobbin yarn on the friction roller when the winding machine is working. In addition, the pressure sensor is too large, and the existing winding machine has a compact structure and is inconvenient to install. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is the first three-dimensional structural schematic diagram of the present invention.

[0044] Figure 2 It is a second three-dimensional structural schematic diagram of the present invention.

[0045] Figure 3 It is a front view of the present invention.

[0046] Figure 4 It is a rear view of the present invention.

[0047] Figure 5 A top view of the present invention.

[0048] Figure 6 This is a schematic diagram of the bobbin point set obtained by scanning for the present invention.

[0049] Figure 7 This is a flow chart of measuring the volume of bobbin yarn in step 2 of the winding method provided by the present invention.

[0050] Figure 8 The output torque T is calculated in the winding method provided by the present invention. s Schematic diagram of some dimensional parameters involved. DETAILED DESCRIPTION

[0051] 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.

[0052] like Figure 2 , Figure 3 , Figure 4 As shown, a contact back pressure dynamic control device based on the bobbin integral calculation model includes a circuit control board (not shown in the figure), a rotating arm 7, a friction bracket 8, a friction roller 9, a bobbin 10, a bobbin 11, a torque shaft 13, a base 17, a first support frame 18, a second support frame 19, a torque control component and a contour acquisition component.

[0053] The two friction brackets 8 arranged at intervals and aligned with each other are fixed on the base 17. The two ends of the friction roller 9 are rotatably connected to the two friction brackets 8. The first support frame 18 and the second support frame 19 arranged at intervals and aligned with each other are fixed on the base 17. The two ends of the torsion shaft 13 are rotatably connected to the top of the first support frame 18 and the second support frame 19.

[0054] The rotating arm 7 is U-shaped and includes a connecting beam fixed as an integral body and two parallel side arms. The connecting beam and the torsion shaft 13 are parallel and fixed to each other. A yarn drum disassembly and assembly structure is provided between the opposite sides of the outer ends of the two side arms. The wound yarn drum 11 is installed on the yarn drum disassembly and assembly structure and can be rotated and wound. The yarn drum disassembly and assembly structure adopts a clamping claw structure.

[0055] The axis of the bobbin disassembly and assembly structure, the axis of the friction roller 9 and the axis of the torque shaft 13 are parallel to each other; the bobbin disassembly and assembly structure is located above the friction roller 9; during the yarn winding process, the bobbin yarn installed on the bobbin disassembly and assembly structure is pressed from top to bottom on the friction roller 9. The torque control component is used to apply torque to the rotating arm 7 so that the extrusion force between the bobbin yarn and the friction roller 9 is controlled near the optimal value. The torque control component includes a transmission component and a motor 16. The transmission component includes a synchronous belt 14, a first pulley 12, and a second pulley 15. The motor 16 specifically adopts an AC servo motor. The motor 16 is mounted on a base 17. The first pulley 12 and the second pulley 15 are respectively fixed on the torque shaft 13 and the output shaft of the motor 16. The first pulley 12 and the second pulley 15 are connected by a synchronous belt 14. As a result, the motor drives the second pulley to rotate the first pulley through the synchronous belt, and then transmits the torque to the rotating arm to achieve contact back pressure balance on the friction roller.

[0056] like Figure 1 , Figure 2As shown, the contour acquisition component is used to collect the surface contour of the bobbin yarn, and then calculate the volume and weight of the bobbin yarn in real time; the contour acquisition component includes a radial laser ranging sensor 1 (denoted as F-LDS), a first axial laser ranging sensor 2 (denoted as R-LDS), a second axial laser ranging sensor 3 (denoted as L-LDS), a front linear slide 4, a first side linear slide 5 and a second side linear slide 6.

[0057] The front linear slide 4 is mounted on the connecting beam of the rotating arm 7. A clearance groove is provided on the side arm along the length direction of the side arm. The first side linear slide 5 and the second side linear slide 6 are respectively mounted in the clearance grooves of the two side arms of the rotating arm 7. The length direction of the front linear slide 4 is parallel to the axis of the bobbin disassembly and assembly structure; the length directions of the first side linear slide 5 and the second side linear slide 6 aligned with each other are both perpendicular to the axis of the bobbin disassembly and assembly structure.

[0058] The radial laser distance sensor 1, the first axial laser distance sensor 2, and the second axial laser distance sensor 3 are respectively installed on the sliders of the front linear slide 4, the first side linear slide 5, and the second side linear slide 6. The moving paths of the detection points of the first axial laser distance sensor 2 and the second axial laser distance sensor 3 are perpendicularly intersected with the axis of the yarn tube disassembly and assembly structure, so that the first axial laser distance sensor 2 and the second axial laser distance sensor 3 can move radially along the yarn tube disassembly and assembly structure, thereby detecting the axial size change (i.e., the concave and convex situation) of the end face of the yarn tube 10 from the center to the edge at different positions. The front linear slide 4, the first side linear slide 5, and the second side linear slide 6 are all electric slides.

[0059] The laser emission direction of the radial laser distance measuring sensor 1 is perpendicular to the axis of the torque shaft 13, so that the radial laser distance measuring sensor 1 can directly measure the diameter change of the bobbin yarn at different axial positions.

[0060] According to the triangulation principle of the laser ranging sensor (LDS), each sensor has an independent measurement coordinate system. In this embodiment, in order to facilitate data collection and subsequent processing, a unified coordinate system is established, such as Figure 5 shown.

[0061] In this embodiment, the range of the laser distance sensor is 0 to 5V, the digital measurement value range is -140 to 140mm, the A / D module range is 0 to 2000, and the conversion formula is as follows:

[0062] M=V A / D ×(5÷2000)×140÷2.5-140

[0063] Where: M is the digital measurement value; V A / D It is the digital quantity of A / D module.

[0064] The method for winding the bobbin yarn using the contact back pressure dynamic control device based on the bobbin yarn integral calculation model is as follows:

[0065] Step 1: Install the yarn drum on the yarn drum disassembly and assembly structure, and make the yarn drum rest against the top of the friction roller. The external servo motor drives the friction roller to rotate, driving the yarn drum to rotate, and the yarn is wound.

[0066] Step 2: yarn winding volume measurement stage, the flow chart is as follows Figure 7 shown.

[0067] 2-1. During the rotation of the yarn tube, the three laser ranging sensors are controlled by the controller to scan along their own moving trajectories to obtain data points; the three laser ranging sensors project the measured data points into the same plane coordinate system according to their own positions to obtain the original point set of the half-section contour of the yarn tube.

[0068] In the original point set, the points in the middle area constitute the bobbin point set, and the remaining points are invalid points and non-modeling demand points when the bobbin is not detected. In addition, the original point set is constructed by splicing discrete points measured by each sensor, and there is a problem of overlapping points. Therefore, it is impossible to directly use the original point set for mathematical modeling to obtain the winding volume; therefore, it is necessary to perform data denoising on the original point set, remove invalid points and non-modeling demand points, and obtain the bobbin point set. The bobbin point set includes three subsets; the points in the three subsets come from three laser ranging sensors respectively. Figure 6 In , the three subsets are the points between point a and point d, the points between point a and point b, and the points between point b and point c.

[0069] 2-2. The three subsets were fitted by nonlinear least squares method to obtain the two end profile curves and side profile curves of the package yarn (such as Figure 6 As shown in the figure), it is more effective for the surface trend characteristics of the package yarn.

[0070] In the least squares fitting method, the curve function The selection of is crucial. The present invention adopts the optimal function search algorithm, the principle of which is to find the function whose determination coefficient after fitting is closest to 1 from the function library. The formula for calculating the coefficient of determination is as follows:

[0071]

[0072] In the formula, R 2 is the coefficient of determination; S res is the residual sum of squares; S tot is the total sum of squares; i is the number of given values; y i is the given i-th y value; y is the average value; f iis the predicted value of the i-th fitted model.

[0073] 2-3. Connect the ends of the two end profile curves away from the side profile curve with a straight line to obtain the bobbin generatrix; splice the side profile curve, the two end profile curves and the bobbin generatrix obtained in step 2-2 to obtain a closed bobbin half-section profile. Rotate the bobbin half-section profile around the bobbin axis to obtain a three-dimensional model of the bobbin.

[0074] The volume V of the yarn is calculated using the three-dimensional model of the yarn as follows:

[0075]

[0076] Among them, x is the x-axis coordinate of the half-section profile of the bobbin yarn; z is the z-axis coordinate of the half-section profile of the bobbin yarn; L3 is the function of the bobbin generatrix; L1 is the function of the side profile curve; L2 and L3 are functions of the two end face profile curves; a and b are the z-axis coordinates of the intersection of the side profile curve and the two end face profile curves respectively; c and d are the z-axis coordinates of the intersection of the bobbin generatrix and the two end face profile curves respectively.

[0077] 2-4. Calculate the net weight G of the package yarn based on the package yarn volume V and the package yarn winding density γ s The formula is as follows:

[0078] G s =V·γ

[0079] Step 3: The motor balances the contact back pressure of the friction roller through the supporting force of the rotating arm.

[0080] Using torque balance, the contact back pressure F between the package yarn and the friction roller is established. N , the gravity of the rotating arm G b , Net weight of package 10 G s , the weight of the yarn cone 11 G t , weight of yarn tube disassembly and assembly structure G c , the relationship between the torque T applied by the torque control assembly to the torque shaft 13 is as follows:

[0081] F N ·L·cos(β-α)+T=G b ·L b ·cosβ+(G s +G t +G c )·L·cosβ

[0082] Wherein, β is the inclination angle of the force arm of the rotating arm on the bobbin relative to the horizontal plane (specifically, the angle between the plane formed by the axis of the torsion shaft 13 and the axis of the bobbin 11 and the horizontal plane); α is the support angle of the friction roller on the bobbin (specifically, the angle between the plane formed by the axis of the friction roller and the axis of the bobbin 11 and the vertical plane passing through the axis of the friction roller); L is the center distance between the torsion shaft 13 and the bobbin 11; L b It is the distance from the center of gravity of the rotating arm to the axis of the torque shaft 13.

[0083] In this embodiment, the tilt angle β is obtained by an encoder.

[0084] The support angle α changes with the change of the tilt angle β, and the relationship is as follows:

[0085]

[0086] Among them, Δx is the horizontal distance between the axis of the bobbin yarn and the axis of the friction roller when the rotating arm is in the horizontal state; Δh is the vertical distance between the axis of the bobbin yarn and the axis of the friction roller when the rotating arm is in the horizontal state.

[0087] In this embodiment, the value of Δx is 0; the value of Δh is 10 cm.

[0088] Based on the above formula, it can be seen that if the contact back pressure F N The value of is constant as the target pressure F a , then it is necessary to set the output torque T of the motor 16 s The following conditions are met:

[0089] T s =T / i=[G b ·L b ·cosβ+(G s +G t +G c )·L·cosβ-F N ·L·cos(β-α)] / i

[0090] Wherein, i is the transmission ratio between the motor 16 and the torque shaft 13, that is, the transmission ratio of the transmission assembly, and in this embodiment, the value is selected as 2.5.

[0091] In some embodiments, since the arm length L of the rotating arm is significantly greater than the diameter of the bobbin 11, the value of the inclination angle β is small, so (LL·cosβ) is much smaller than Δh; when the value of Δx is 0, the value of tanα is close to 1, so α is close to 0; therefore, cos(β-α)≈cosβ; thus, a simplified relationship can be obtained:

[0092] T s =[G b ·L b·cosβ+(G s +G t +G c -F N )·L·cosβ] / i

[0093] In a further embodiment, in order to further simplify the calculation, cosβ is approximated to 1, and a further simplified relationship is obtained:

[0094] T s =[G b ·L b +(G s +G t +G c -F N )·L] / i

[0095] In a further embodiment, the net weight G of the package 10 is introduced s The correction coefficient k that changes in stages is used to reduce the error caused by simplification.

[0096] T s = k[G b ·L b +(G s +G t +G c -F N )·L] / i

[0097] The correction coefficient k has multiple candidate values, and its value varies with the net weight G of the package yarn 10. s The change of T can be used to select different candidate values ​​in stages, which can reduce the computing power requirements and make the calculated T s Close to [G b ·L b ·cosβ+(G s +G t +G c )·L·cosβ-F N ·L·cos(β-α)] / i, to ensure the accuracy of contact back pressure.

[0098] The above is a detailed introduction to the online detection of the contact back pressure of the bobbin winding forming based on piezoelectric sensing and the motor balancing method provided in an embodiment of the present invention. The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for general technical personnel in this field, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A contact back pressure dynamic control device based on a yarn cone integral calculation model, comprising a rotating arm (7), a friction roller (9), a torsion shaft (13) and a base (17); the friction roller (9) is rotatably connected to the base (17); the torsion shaft (13) is rotatably connected to the base (17) through a support frame; the rotating arm (7) is U-shaped, comprising a connecting beam and two parallel side arms; the connecting beam is fixed to the torsion shaft (13); a yarn cone disassembly and assembly structure is arranged between the outer ends of the two side arms; the axis of the yarn cone disassembly and assembly structure, the axis of the friction roller (9) and the axis of the torsion shaft (13) are parallel to each other; the yarn cone disassembly and assembly structure is located above the friction roller (9); and the characteristics are as follows: The bobbin winding and forming device for dynamically controlling the contact back pressure also includes a torque control component and a profile collection component; the torque control component includes a transmission component and a motor (16); the motor (16) is installed on a base (17); the output shaft of the motor (16) is connected to the torque shaft (13) through the transmission component; the profile collection component collects the axial cross-section profile of the bobbin through a laser distance measuring sensor; During the yarn winding process, the yarn cone installed on the yarn cone disassembly and assembly structure is pressed from top to bottom against the friction roller (9); as the amount of yarn wound on the yarn cone increases, the weight of the yarn cone increases; the torque output by the motor (16) gradually increases, so that the contact back pressure between the yarn cone and the friction roller (9) is controlled within a preset range.

2. The contact back pressure dynamic control device based on the package yarn integral calculation model according to claim 1 is characterized in that: The contour acquisition component comprises a radial laser distance measuring sensor (1), a first axial laser distance measuring sensor (2), a second axial laser distance measuring sensor (3), a front linear slide (4), a first side linear slide (5) and a second side linear slide (6); the front linear slide (4) is mounted on a connecting beam of a rotating arm (7); the first side linear slide (5) and the second side linear slide (6) are respectively mounted on two side arms of the rotating arm (7); the radial laser distance measuring sensor (1), the first axial laser distance measuring sensor (2) and the second axial laser distance measuring sensor (3) are respectively mounted on sliders of the front linear slide (4), the first side linear slide (5) and the second side linear slide (6); the moving direction of the radial laser distance measuring sensor (1) is parallel to the axis of the yarn tube disassembly and assembly structure; the moving directions of the first axial laser distance measuring sensor (2) and the second axial laser distance measuring sensor (3) are both perpendicular to the axis of the yarn tube disassembly and assembly structure.

3. The contact back pressure dynamic control device based on the package yarn integral calculation model according to claim 2 is characterized in that: The side arm is provided with a clearance groove arranged along the length direction of the side arm; the first side linear slide (5) and the second side linear slide (6) are respectively installed in the clearance grooves of the two side arms; the moving paths of the detection points of the first axial laser distance measuring sensor (2) and the second axial laser distance measuring sensor (3) are perpendicular to the axis of the yarn tube disassembly and assembly structure; the laser emission direction of the radial laser distance measuring sensor (1) is perpendicular to the axis of the torque shaft (13).

4. The contact back pressure dynamic control device based on the package yarn integral calculation model according to claim 1 is characterized in that: The transmission assembly comprises a synchronous belt (14), a first pulley (12), and a second pulley (15); the motor (16) is mounted on a base (17); the first pulley (12) and the second pulley (15) are respectively fixed on a torque shaft (13) and an output shaft of the motor (16); the first pulley (12) and the second pulley (15) are connected by a synchronous belt (14).

5. The contact back pressure dynamic control device based on the package yarn integral calculation model according to claim 1 is characterized in that: Two friction brackets (8) are fixed on the friction bracket (8) and are arranged at intervals and aligned with each other; the two ends of the friction roller (9) and the two friction brackets (8) respectively form a rotating pair.

6. A contact back pressure dynamic control method, characterized in that: Using the contact back pressure dynamic control device based on the package yarn integral calculation model as claimed in claim 2; the contact back pressure dynamic control method comprises the following steps: Step 1: Install the yarn tube on the yarn tube disassembly and assembly structure; and make the yarn tube rest against the top of the friction roller (9); the external servo motor drives the friction roller (9) to rotate, driving the yarn tube to rotate, and winding the yarn; Step 2: yarn bobbin winding volume measurement stage; Step 2-1. During the rotation of the bobbin, three laser distance measuring sensors scan along their own moving trajectories to obtain data points; the three laser distance measuring sensors project the measured data points into the same plane coordinate system according to their own positions to obtain a bobbin point set corresponding to the bobbin profile; the bobbin point set includes three subsets; the points in the three subsets come from the three laser distance measuring sensors respectively; Step 2-2. Use nonlinear least square method to fit the three subsets respectively to obtain two end profile curves and side profile curves of the package yarn; Step 2-3. Connect the ends of the two end profile curves away from the side profile curve with a straight line to obtain the bobbin generatrix; the side profile curve, the two end profile curves and the bobbin generatrix together form a bobbin half-section profile; obtain the bobbin volume V through the bobbin half-section profile; Step 2-4. Calculate the net weight G of the package s as follows: G s =V·γ Among them, the winding density of the package yarn is γ; Step 3: According to the net weight of the yarn G s , adjusting the output torque of the motor (16) so that the contact back pressure between the bobbin yarn and the friction roller (9) is controlled within a preset range.

7. A bobbin winding method according to claim 6, characterized in that: The expression of the package volume V is: Among them, x is the axial coordinate of the half-section profile of the bobbin yarn; z is the radial coordinate of the half-section profile of the bobbin yarn; L3 is the function of the bobbin generatrix; L1 is the function of the side profile curve; L2 and L3 are functions of the two end face profile curves; a and b are the radial coordinates of the intersection of the side profile curve and the two end face profile curves respectively; c and d are the radial coordinates of the intersection of the bobbin generatrix and the two end face profile curves respectively.

8. A bobbin winding method according to claim 6, characterized in that: Adjust the output torque T of the motor (16) s The expression is as follows: T s =[G b ·L b ·cosβ+(G s +G t +G c )·L·cosβ-F N ·L·cos(β-α)] / i Among them, F N To build the contact back pressure between the package yarn and the friction roller; G b is the gravity of the rotating arm; G s is the net weight of the package (10); G t is the weight of the yarn tube (11); G c is the weight of the yarn tube disassembly and assembly structure; β is the inclination angle of the force arm of the rotating arm on the yarn tube relative to the horizontal plane; α is the support angle of the friction roller on the yarn tube; L is the center distance between the torsion shaft (13) and the yarn tube (11); L b is the distance from the center of gravity of the rotating arm to the axis of the torsion shaft (13); The tilt angle β is obtained by an encoder that detects the rotation angle of the torque shaft (13); The relationship between the support angle α and the inclination angle β is as follows: Among them, Δx is the horizontal distance between the axis of the bobbin yarn and the axis of the friction roller when the rotating arm is in the horizontal state; Δh is the vertical distance between the axis of the bobbin yarn and the axis of the friction roller when the rotating arm is in the horizontal state.

9. A bobbin winding method according to claim 6, characterized in that: Adjust the output torque T of the motor (16) s The expression is as follows: T s =[G b ·L b ·cosβ+(G s +G t +G c -F N )·L·cosβ] / i Among them, F N To build the contact back pressure between the package yarn and the friction roller; G b is the gravity of the rotating arm; G s is the net weight of the package (10); G t is the weight of the yarn tube (11); G c is the weight of the yarn tube disassembly and assembly structure; β is the inclination angle of the force arm of the rotating arm on the yarn tube relative to the horizontal plane; L is the center distance between the torsion shaft (13) and the yarn tube (11); L b is the distance from the center of gravity of the rotating arm to the axis of the torsion shaft (13); The inclination angle β is obtained by an encoder that detects the rotation angle of the torque shaft (13).

10. A bobbin winding method according to claim 6, characterized in that: Adjust the output torque T of the motor (16) s The expression is as follows: T s =k[G b ·L b +(G s +G t +G c -F N )·L] / i Among them, F N To build the contact back pressure between the package yarn and the friction roller; G b is the gravity of the rotating arm; G s is the net weight of the package (10); G t is the weight of the yarn tube (11); G c is the weight of the yarn tube disassembly and assembly structure; L is the center distance between the torque shaft (13) and the yarn tube (11); L b is the distance from the center of gravity of the rotating arm to the axis of the torque shaft (13); k is the correction coefficient.

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