Sewing control method

Abstract

A sewing control method, relating to the technical field of sewing machines. A main shaft (1) drives a needle (5) to move up and down, a feed motor (2) is configured to drive a feed dog (4) to move forward and backward, and a feed dog lift motor (3) is configured to drive the feed dog (4) to move up and down; the trajectory of the feed motor (2) and the feed dog lift motor (3) jointly driving the feed dog (4) to move when sewing a thin material is set as a standard trajectory; the trajectory of the feed motor (2) and the feed dog lift motor (3) jointly driving the feed dog (4) to move when sewing a thick material is set as a thick material trajectory; in one feeding cycle where the feed dog (4) moves along the thick material trajectory, the duration of a feeding phase is shorter than that of a non-feeding phase; the rotational angle relationship between the feed motor (2) and the feed dog lift motor (3) in thick material trajectory parameters is consistent with that in standard trajectory parameters, ensuring the shape of the thick material trajectory to be the same as that of the standard trajectory. The feeding timing sequence can be changed when the movement trajectory of the feed dog (4) is unchanged, so as to delay the feeding start time and advance the feeding end time, thereby preventing needle breakage during thick material sewing.

Description

A sewing control method Technical Field

[0001] This invention relates to the field of sewing machine technology, and more particularly to a sewing control method. Background Technology

[0002] When a sewing machine is working, the feed dog's elliptical trajectory offers advantages such as high-speed tracking, excellent adaptability to different fabrics, and low vibration and noise. Currently, the most widely used feed dog trajectory in sewing machines is the elliptical trajectory. In one feeding cycle, the feed dog moves above the needle plate from bottom to top to bottom, feeding the fabric. The non-feeding time is the period between the feed dog's downward movement to the needle plate and its upward movement to the needle plate.

[0003] In standard mode, the feed dog follows a standard trajectory, resembling an ellipse. The feeding and non-feeding times within a single feeding cycle are very close, meaning the feed dog spends approximately half the time feeding material above the needle plate. Furthermore, the needle and feed dog are synchronized; as the needle moves downwards to the needle plate, the feed dog also moves downwards to the needle plate. This standard trajectory in standard mode is suitable for thin materials with a typical thickness.

[0004] For the thick material mode, that is, when sewing thicker fabrics, especially extremely thick fabrics, if the feed dog movement trajectory adopts the standard trajectory of the standard mode, due to the increased fabric thickness, the needle will contact the upper surface of the fabric in advance. At this time, the feed dog is still moving with the fabric, so the needle that is piercing the fabric will be deflected by the moving fabric, and even the needle may break.

[0005] Existing technologies typically address needle breakage caused by the needle pulling on the fabric during thick fabric sewing by altering the feed dog's movement trajectory. For example, patent CN103290621B discloses a sewing machine including a main motor and a feed motor. The main motor moves the needle up and down. The main motor moves the feed dog vertically, while the feed motor moves the feed dog horizontally. Together, they form a specific feed dog movement trajectory. When the fabric is thick, the forward and backward movement of the feed dog is stopped early, changing its movement trajectory to avoid needle breakage caused by the needle pulling on the fabric. In this solution, the curve showing the correspondence between the upper shaft angle and the feed shaft angle in the trajectory data for thick fabrics exhibits a significant inflection point. The discontinuous slope exacerbates the control of the shaft rotation angle by the electronic control system, easily leading to poor trajectory matching and high noise at high speeds. Furthermore, this solution uses only a single feed motor, and the power source for lifting the feed dog still comes from the main motor. This mechanical transmission prevents the alteration of the feed dog's timing relative to the main shaft, limiting its adaptability to thick fabric stitches. Summary of the Invention

[0006] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is to provide a sewing control method that can change the feeding sequence while keeping the feed dog movement trajectory unchanged, thereby delaying the feeding start time and advancing the feeding end time, and preventing needle breakage problems when sewing thick materials.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0008] This invention provides a sewing control method, in which a main shaft drives the needle to move up and down, a feed motor drives the feed dog to move back and forth, and a lift motor drives the feed dog to move up and down. When sewing thin materials, the trajectory of the feed dog driven by both the feed motor and the lift motor is defined as the standard trajectory; when sewing thick materials, the trajectory of the feed dog driven by both the feed motor and the lift motor is defined as the thick material trajectory. In one feeding cycle of the feed dog moving along the thick material trajectory, the feeding time is less than the non-feeding time. The rotation angle relationship between the feed motor and the lift motor in the thick material trajectory parameters is consistent with the rotation angle relationship between the feed motor and the lift motor in the standard trajectory parameters, so that the shape of the thick material trajectory is the same as the shape of the standard trajectory.

[0009] Preferably, the proportion of fabric feeding time in the corresponding thick material trajectory is determined according to the thickness of the fabric, and the corresponding thick material trajectory parameters are determined according to the proportion of fabric feeding time.

[0010] Preferably, based on different fabric thicknesses, multiple thick material trajectories with correspondingly different fabric feeding time ratios are set.

[0011] Preferably, the control module stores standard trajectory parameters and thick material trajectory parameters, and sets a fabric thickness threshold. When the fabric thickness is less than the fabric thickness threshold, the control module controls the feeding motor and the lifting motor to drive the feeding teeth using the standard trajectory parameters. When the fabric thickness is not less than the fabric thickness threshold, the control module controls the feeding motor and the lifting motor to drive the feeding teeth using the thick material trajectory parameters.

[0012] Preferably, based on different fabric thicknesses, multiple thick material trajectories with correspondingly different fabric feeding time ratios are set, and the parameters of the multiple thick material trajectories are all stored in the control module; when the fabric thickness is not less than the fabric thickness threshold, the corresponding thick material trajectory is selected according to the fabric thickness, and the control module controls the feeding motor and the lifting tooth motor to drive the feeding teeth with the selected thick material trajectory parameters.

[0013] Preferably, a detection sensor for detecting the thickness of the sewing fabric is provided. The detection sensor is communicatively connected to the control module. The control module controls the feeding motor and the lifting motor to drive the feed dog according to the fabric thickness detected by the detection sensor and the corresponding standard trajectory parameters or thick material trajectory parameters.

[0014] Preferably, the detection sensor is a displacement sensor, which is mounted on the pressure foot.

[0015] Compared with the prior art, the present invention has significant progress:

[0016] The sewing control method of this invention uses a feed motor and a lifter motor, independent of the main shaft, to drive the feed dog's forward and backward movement and up and down movement, respectively. This ensures that the driving sources for the needle's up-and-down movement, the feed dog's forward and backward movement, and the feed dog's up-and-down movement are all independent. Therefore, the driving patterns of the feed motor and lifter motor can be freely customized. Specific feed dog movement trajectories and feed durations can be achieved by changing the timing parameters of the feed motor and lifter motor relative to the main shaft. This allows for changing the timing of the feed motor and lifter motor relative to the main shaft and reducing the feed time without altering the shape of the feed dog's movement trajectory. This results in a delayed start time and an advanced end time for feed, eliminating the problem of needle breakage caused by the needle dragging the fabric. By controlling the rotational timing of the main shaft, feed motor, and lifter motor, the feed dog's movement trajectory shape can remain unchanged while varying the feed time. This broadens the adaptability to fabrics of different thicknesses. With the overall machine structure unchanged, adaptation to different types of fabrics can be achieved simply by changing the control program. Attached Figure Description

[0017] Figure 1 is a schematic diagram of the control structure used in the sewing control method of this invention.

[0018] Figure 2 shows the relationship curves between the rotation angles of the feeding motor and the spindle in the standard trajectory parameters (solid line) and the thick material trajectory parameters (dashed line) in the sewing control method of this embodiment of the invention.

[0019] Figure 3 shows the relationship curves between the rotation angles of the tooth-lifting motor and the spindle in the standard trajectory parameters (solid line) and the thick material trajectory parameters (dashed line) in the sewing control method of this embodiment of the invention.

[0020] Figure 4 is a schematic diagram of the standard trajectory in the sewing control method of this embodiment of the invention.

[0021] Figure 5 is a schematic diagram of the thick material trajectory in the sewing control method of this embodiment of the invention.

[0022] Figure 6 shows the relationship between the displacement of the feed dog and the rotation angle of the spindle in the sewing control method of this embodiment of the invention, under the standard trajectory (solid line) and the thick material trajectory (dashed line).

[0023] Figure 7 shows the relationship between the displacement of the feed dog and the rotation angle of the spindle in the sewing control method of this embodiment of the invention, under the standard trajectory (solid line) and the thick material trajectory (dashed line).

[0024] Figure 8a and 8b are schematic diagrams showing the position of the needle when the fabric finishes moving under the standard trajectory and the thick material trajectory, respectively, in the sewing control method of the present invention.

[0025] Figure 9 shows the relationship curves of the rotation angles of the feed motor and the lifting motor under the standard trajectory (solid line) and the thick material trajectory (dashed line) in the sewing control method of this embodiment of the invention.

[0026] Figure 10 is a control logic diagram of the sewing control method according to an embodiment of the present invention.

[0027] The reference numerals in the attached drawings are explained as follows: 1 Main shaft; 10 Main motor; 2 Feed motor; 3 Tooth lifting motor; 4 Feed dog; 5 Needle; 6 Needle plate; 61 Needle plate surface. Detailed Implementation

[0028] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0029] In the description of this invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0030] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0031] Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0032] Figures 1 to 10 show an embodiment of the sewing control method provided by the present invention.

[0033] Referring to Figure 1, in the control structure of the sewing control method in this embodiment, the main shaft 1 drives the needle 5 to move up and down. The main shaft 1 is driven by the main motor 10, and the needle 5 is located above the needle plate 6. A feed motor 2 drives the feed dog 4 to move back and forth, and a lift motor 3 drives the feed dog 4 to move up and down. The back-and-forth movement and up-and-down movement of the feed dog 4 combine to form the motion trajectory of the feed dog 4 during fabric feeding. By setting the feed motor 2 and lift motor 3, which are independent of the main shaft 1, to drive the feed dog 4 to move back and forth and up and down respectively, the driving sources of the needle 5's up and down movement, the feed dog 4's back-and-forth movement, and the feed dog 4's up and down movement are all independent of each other. Therefore, the driving rules of the feed motor 2 and lift motor 3 can be freely customized. Thus, by changing the timing parameters of the feed motor 2 and lift motor 3 relative to the main shaft 1, a specific feed dog 4 motion trajectory and fabric feeding time can be achieved.

[0034] In the sewing control method of this embodiment, the trajectory of the feed motor 2 and the lifting motor 3 jointly driving the feed dog 4 to move when sewing thin material is set as the standard trajectory, and the trajectory of the feed motor 2 and the lifting motor 3 jointly driving the feed dog 4 to move when sewing thick material is set as the thick material trajectory.

[0035] The standard trajectory refers to the standard trajectory in the standard mode of the existing technology, which is applicable to thin materials with a conventional thickness. As shown by the solid lines in Figures 2 and 3, the rotation angle relationship between the feeding motor 2 and the main shaft 1, and the rotation angle relationship between the lifting motor 3 and the main shaft 1, in the standard trajectory parameters all exhibit a relationship similar to a sine or cosine. The standard trajectory synthesized by the feeding motor 2 and the lifting motor 3 jointly driving the feed dog 4 is shown in Figure 4, and it presents a shape similar to an ellipse. During one feeding cycle of the feed dog 4 moving along the standard trajectory, within the feeding time t2, the feed dog 4 is above the needle plate surface 61 of the needle plate 6, which is the feeding state that drives the fabric movement. The rotation angle of the feed motor 2 swings from the maximum value to the minimum value (or from the minimum value to the maximum value), and the rotation angle of the lifting motor 3 swings from the middle value to one side (such as the maximum value) and then returns to the middle value. During the non-feeding time t1, the feed dog 4 is below the needle plate surface 61 of the needle plate 6, which is the non-feeding state that does not contact the fabric. The rotation angle of the feed motor 2 swings from the minimum value to the maximum value (or from the maximum value to the minimum value), and the rotation angle of the lifting motor 3 swings from the middle value to the other side (such as the minimum value) and then returns to the middle value. The duration of the feeding time t2 and the non-feeding time t1 are very close, that is, the feed dog 4 moves above the needle plate surface 61 to feed for about half the time.

[0036] The thick material trajectory is the movement trajectory of the feed dog 4 in the thick material sewing mode, which is suitable for sewing thicker fabrics, especially extremely thick fabrics. As shown by the dotted lines in Figures 2 and 3, these represent the rotation angle relationship between the feed motor 2 and the main shaft 1, and the rotation angle relationship between the lifting dog motor 3 and the main shaft 1, respectively, in the thick material trajectory parameters. The thick material trajectory synthesized by the feed motor 2 and the lifting dog motor 3 jointly driving the feed dog 4 is shown in Figure 5. During one feeding cycle of the feed dog 4 moving along the thick material trajectory, within the feeding time t4, the feed dog 4 is above the needle plate surface 61 of the needle plate 6, which is the feeding state that drives the fabric movement. The rotation angle of the feed motor 2 completes the angular position from the maximum value to the minimum value (or from the minimum value to the maximum value), and the rotation angle of the lifting tooth motor 3 completes the angular position from the middle value to one side (such as the maximum value) and then returns to the angular position of the middle value. During the non-feeding time t3, the feed dog 4 is below the needle plate surface 61 of the needle plate 6, which is the non-feeding state that does not contact the fabric. The rotation angle of the feed motor 2 completes the angular position from the minimum value to the maximum value (or from the maximum value to the minimum value), and the rotation angle of the lifting tooth motor 3 completes the angular position from the middle value to the other side (such as the minimum value) and then returns to the angular position of the middle value. The duration of the feeding time t4 is less than the duration of the non-feeding time t3. That is, in one feeding cycle, the feeding time t4 is shortened and the non-feeding time t3 is increased. Therefore, compared to the standard trajectory, the feeding time of the thick material trajectory is shorter, allowing for a later start and an earlier end to the feeding process.

[0037] As shown by the solid lines in Figures 6 and 7, the displacements of the feed dog 4 in its forward and backward movements and its up and down movements relative to the rotation angle of the main shaft 1 under the standard trajectory are represented by their respective solid lines. The zero point of the forward and backward displacement of the feed dog 4 represents the midpoint of its forward and backward movement, and the zero point of the up and down displacement of the feed dog 4 represents the midpoint of its up and down movements, which is also approximately equal to the height of the needle plate surface 61 of the needle plate 6. As shown by the dashed lines in Figures 6 and 7, the displacements of the feed dog 4 in its forward and backward movements and its up and down movements relative to the rotation angle of the main shaft 1 under the thick material trajectory are represented by their respective solid lines. Compared with the standard trajectory, the thick material trajectory has a shorter feed time and a longer non-feed time in one feeding cycle. The forward and backward displacement curve of the feed dog 4 under the thick material trajectory is steeper during the feed time, indicating that the forward and backward movement speed of the feed dog 4 is faster. Therefore, less time is required for the same stitch length. Thus, the feed time of the thick material trajectory is shorter, which can achieve the effect of starting feed later and ending feed earlier. Therefore, as shown in Figure 8, when the main shaft 1 drives the needle 5 to maintain its motion, compared to the standard trajectory, in the thick material trajectory, the needle 5 is positioned higher than the needle plate surface 61 of the needle plate 6. The feed dog 4 then sinks below the needle plate surface 61 and does not feed material, thus ending the feeding process earlier. Because the feed dog 4 completes the feeding earlier in the thick material trajectory, when the fabric stops moving, the needle 5 is still a considerable distance from the needle plate 6, thus preventing the needle 5 from pulling the fabric and causing needle breakage.

[0038] Meanwhile, the rotation angle relationship between the feeding motor 2 and the lifting tooth motor 3 in the thick material trajectory parameters is consistent with the rotation angle relationship between the feeding motor 2 and the lifting tooth motor 3 in the standard trajectory parameters, making the shape of the thick material trajectory the same as the shape of the standard trajectory. The feed tooth 4 is driven by both the feeding motor 2 and the lifting tooth motor 3. Therefore, the motion trajectory shape of the feed tooth 4 is determined by the relative relationship between the rotation angles of the feeding motor 2 and the lifting tooth motor 3, and is independent of the speed of the oscillation of the angular position. When the angular position of the feeding motor 2 oscillates rapidly, the lifting tooth motor 3 also oscillates rapidly. If the corresponding relationship between the oscillation angles of the two remains unchanged, then the motion trajectory shape of the feed tooth 4 will not change. As shown in Figure 9, when the rotation angle of the feeding motor 2 is at h0, the phase difference between the rotation angles of the feeding motor 2 and the lifting motor 3 under the standard trajectory (solid line) is h1, and the phase difference between the rotation angles of the feeding motor 2 and the lifting motor 3 under the thick material trajectory (dashed line) is h2, h1 = h2. Furthermore, throughout the entire operating cycle, for any h0, h1 = h2 remains constant. That is, the rotation angle relationship between the feeding motor 2 and the lifting motor 3 in the thick material trajectory parameters is consistent with the rotation angle relationship between the feeding motor 2 and the lifting motor 3 in the standard trajectory parameters. The position of the feed tooth 4 is determined by the rotation angles of the feeding motor 2 and the lifting motor 3. The consistent rotation angle relationship between the feeding motor 2 and the lifting motor 3 also indicates that the motion trajectory shape of the feed tooth 4 is the same. Therefore, by making the rotation angle relationship between the feeding motor 2 and the lifting motor 3 in the thick material trajectory parameters consistent with the rotation angle relationship between the feeding motor 2 and the lifting motor 3 in the standard trajectory parameters, the shape of the thick material trajectory can be the same as the shape of the standard trajectory. Therefore, the shape of the thick material trajectory shown in Figure 5 is the same as that of the standard trajectory shown in Figure 4, both of which are elliptical in shape.

[0039] Therefore, the sewing control method of this embodiment achieves the reduction of fabric feeding time by changing the timing of the feed motor 2 and the lifting motor 3 relative to the main shaft 1 without changing the shape of the feed dog 4's movement trajectory. This results in a delayed start time and an advanced end time for the feed, eliminating the problem of needle breakage caused by the needle 5 supporting the fabric. By controlling the rotation timing of the main shaft 1, feed motor 2, and lifting motor 3, the shape of the feed dog 4's movement trajectory can remain unchanged, but different fabric feeding times can be achieved. This broadens the adaptability to fabrics of different thicknesses. Without changing the overall machine structure, different types of fabrics can be adapted simply by changing the control program.

[0040] In the sewing control method of this embodiment, preferably, the proportion of fabric feeding time in the required thick material trajectory is determined according to the thickness of the fabric. Since the rotation angle relationship between the feed motor 2 and the lifting motor 3 in the thick material trajectory parameters is consistent with the rotation angle relationship between the feed motor 2 and the lifting motor 3 in the standard trajectory parameters, the corresponding thick material trajectory parameters can be determined based on the proportion of fabric feeding time, thereby obtaining thick material trajectory parameters corresponding to the fabric thickness. Furthermore, based on different fabric thicknesses, multiple thick material trajectories with correspondingly different proportions of fabric feeding time are set, thereby obtaining thick material trajectories that correspond one-to-one with different fabric thicknesses. Therefore, during sewing, the corresponding thick material trajectory can be selected according to the thickness of the fabric being sewn, ensuring good adaptability to fabrics of different thicknesses.

[0041] In the sewing control method of this embodiment, preferably, standard trajectory parameters and thick material trajectory parameters are stored in the control module, and a fabric thickness threshold is set, which is also stored in the control module. The control module is an existing electronic control structure of a conventional sewing machine. When the fabric thickness is less than the fabric thickness threshold, that is, when the fabric thickness is within the fabric thickness threshold, the fabric is determined to be a thin material suitable for the standard trajectory. The control module controls the feed motor 2 and the lifting tooth motor 3 to drive the feed dog 4 according to the standard trajectory parameters. That is, the angular position of the feed motor 2 and the lifting tooth motor 3 is controlled to swing according to the rotation angle relationship between the feed motor 2 and the main shaft 1 and the rotation angle relationship between the lifting tooth motor 3 and the main shaft 1 in the standard trajectory parameters, thereby driving the feed dog 4 to move along the standard trajectory to feed the material. When the fabric thickness is not less than the fabric thickness threshold (i.e., the fabric thickness is not within the fabric thickness threshold), the fabric is determined to be a thick material suitable for the thick material trajectory. The control module controls the feeding motor 2 and the lifting motor 3 to drive the feeding teeth 4 according to the thick material trajectory parameters. Specifically, the control module controls the rotation angles of the feeding motor 2 and the main shaft 1, and the lifting motor 3 and the main shaft 1, to swing the angular positions of the feeding motor 2 and the lifting motor 3, driving the feeding teeth 4 to move along the thick material trajectory to feed the fabric. Furthermore, multiple thick material trajectory parameters with corresponding different feeding time ratios based on different fabric thicknesses are stored in the control module. When the fabric thickness is not less than the fabric thickness threshold, the corresponding thick material trajectory is selected according to the fabric thickness, and the control module controls the feeding motor 2 and the lifting motor 3 to drive the feeding teeth 4 according to the selected thick material trajectory parameters.

[0042] In this embodiment, preferably, a detection sensor for detecting the thickness of the fabric being sewn is provided. The detection sensor is communicatively connected to the control module, and transmits the detected fabric thickness information to the control module. The control module receives this information to obtain the fabric thickness. Based on the fabric thickness detected by the detection sensor, the control module controls the feed motor 2 and the lifting tooth motor 3 to drive the feed dog 4 using corresponding standard trajectory parameters or thick material trajectory parameters. Therefore, by setting a detection sensor to identify the fabric thickness, the corresponding feed dog 4 movement trajectory can be adaptively adjusted and switched according to different fabric thicknesses during the sewing process, further improving the intelligence level of the sewing machine. Preferably, the detection sensor is a displacement sensor, which can be set on the presser foot to automatically sense the fabric thickness.

[0043] In summary, referring to Figure 10, the control logic of the sewing control method in this embodiment includes the following steps.

[0044] Step S1: Set the fabric thickness threshold and store the fabric thickness threshold in the control module.

[0045] Step S2: Obtain the proportion of fabric feeding time in the thick material trajectory: Determine the proportion of fabric feeding time in the corresponding thick material trajectory based on the thickness of the fabric.

[0046] Step S3: Determine the thick material trajectory parameters: Based on the consistency between the rotation angle relationship of the feeding motor 2 and the lifting motor 3 in the thick material trajectory parameters and the rotation angle relationship of the feeding motor 2 and the lifting motor 3 in the standard trajectory parameters, determine the corresponding thick material trajectory parameters according to the proportion of fabric feeding time. Based on different fabric thicknesses, set multiple thick material trajectories with correspondingly different proportions of fabric feeding time, and store both the standard trajectory parameters and the multiple thick material trajectory parameters in the control module.

[0047] Step S4: Obtain the fabric thickness: This is obtained by the detection sensor and transmitted to the control module.

[0048] Step S5: Obtain the angle of spindle 1: determined by the rotation angle of the main motor 10.

[0049] Step S6: Determine whether the fabric thickness is within the fabric thickness threshold: If yes, proceed to step S7; if no, proceed to step S8.

[0050] Step S7: Obtain the rotation angles of the feeding motor 2 and the lifting motor 3 from the standard trajectory parameters: This is determined by the rotation angle relationship curves of the feeding motor 2 and the main shaft 1, and the rotation angle relationship curves of the lifting motor 3 and the main shaft 1 in the standard trajectory parameters.

[0051] Step S8: Obtain the rotation angles of the feeding motor 2 and the lifting motor 3 from the thick material trajectory parameters: This is determined by the rotation angle relationship curves of the feeding motor 2 and the main shaft 1, and the rotation angle relationship curves of the lifting motor 3 and the main shaft 1, which correspond to the thickness of the fabric.

[0052] Step S9: The feeding motor 2 and the tooth lifting motor 3 rotate by the corresponding rotation angle.

[0053] Step S10: Determine whether the angle of spindle 1 has changed: if yes, return to step S5; if no, return to step S10.

[0054] This allows for fully automatic adaptive adjustment during the sewing process.

[0055] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A sewing control method, characterized in that, The main shaft (1) drives the needle (5) to move up and down, the feeding motor (2) drives the feed dog (4) to move back and forth, and the lifting motor (3) drives the feed dog (4) to move up and down. When sewing thin materials, the trajectory of the feed motor (2) and the lifting motor (3) jointly driving the feed dog (4) to move is set as a standard trajectory; When sewing thick materials, the trajectory of the feed motor (2) and the lifting motor (3) jointly driving the feed dog (4) to move is set as the thick material trajectory; During one feeding cycle of the feed tooth (4) moving along the thick material trajectory, the feeding time is less than the non-feeding time. The rotation angle relationship between the feeding motor (2) and the lifting motor (3) in the thick material trajectory parameters is consistent with the rotation angle relationship between the feeding motor (2) and the lifting motor (3) in the standard trajectory parameters, so that the shape of the thick material trajectory is the same as the shape of the standard trajectory.

2. The sewing control method according to claim 1, characterized in that, The proportion of fabric feeding time in the corresponding thick material trajectory is determined based on the thickness of the fabric, and the corresponding thick material trajectory parameters are determined based on the proportion of fabric feeding time.

3. The sewing control method according to claim 2, characterized in that, Based on different fabric thicknesses, multiple thick material trajectories with correspondingly different fabric feeding time ratios are set.

4. The sewing control method according to claim 1, characterized in that, The control module stores the standard trajectory parameters and the thick material trajectory parameters, and sets a fabric thickness threshold. When the fabric thickness is less than the fabric thickness threshold, the control module controls the feeding motor (2) and the lifting motor (3) to drive the feeding teeth (4) using the standard trajectory parameters. When the fabric thickness is not less than the fabric thickness threshold, the control module controls the feeding motor (2) and the lifting motor (3) to drive the feeding teeth (4) using the thick material trajectory parameters.

5. The sewing control method according to claim 4, characterized in that, Based on different fabric thicknesses, multiple thick material trajectories with corresponding different fabric feeding time ratios are set, and the parameters of the multiple thick material trajectories are stored in the control module; when the fabric thickness is not less than the fabric thickness threshold, the corresponding thick material trajectory is selected according to the fabric thickness, and the control module controls the feeding motor (2) and the lifting tooth motor (3) to drive the feeding tooth (4) with the selected thick material trajectory parameters.

6. The sewing control method according to claim 5, characterized in that, A detection sensor is provided for detecting the thickness of the sewing fabric. The detection sensor is communicatively connected to the control module. The control module controls the feeding motor (2) and the lifting motor (3) to drive the feed dog (4) according to the fabric thickness detected by the detection sensor and the corresponding standard trajectory parameters or the thick material trajectory parameters.

7. The sewing control method according to claim 6, characterized in that, The detection sensor is a displacement sensor, which is mounted on the pressure foot.

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