Robot and method for adjusting sewing thread

Abstract

A robot (200) and a method for adjusting a sewing thread (285) are provided. The robot (200) comprises: a robot arm (230) configured to hold an adjustment tool (270); and a controller (210) configured to cause the adjustment tool (270) to partially pass through the thread section along a path defined between a bottom side of the thread section and an outer surface (292) of the object (290), where the sewing thread (285) includes a second end and a first end fixed to the object (290), a plurality of stitches are formed on the object (290) across the sewing area between the first end and the second end, and each stitch includes a thread section having a top side and an opposite bottom side; and moving the adjustment tool (270) upward away from the outer surface (292) to adjust the pitch between the stitches.

Description

Technical Field

[0001] Embodiments of the present disclosure relate generally to the field of industrial robots, and more particularly to industrial robots for sewing objects. Background Art

[0002] In the automotive industry, more and more cars are being manufactured to be equipped with leather-covered steering wheels. Leather not only improves the appearance of the steering wheel, but also improves the comfort of the feel. This is because the leather covering resists the slippery feeling caused by sweat, which means safer driving.

[0003] Typically, leather coverings are manually attached to the raw steering wheel by hand using manual work. The worker first attaches the leather covering to the raw steering wheel by gluing and then sews the leather covering to the raw steering wheel by sewing stitch by stitch. This is labor-intensive and time-consuming. For a single steering wheel, to complete this assembly process, it takes one hour even for an experienced operator. There is an increasing need to automate the assembly process by means of industrial robots. Summary of the invention

[0004] Exemplary embodiments of the present disclosure provide a robot and method for adjusting a sewing line, which can enhance the joint strength of a sewn seam.

[0005] In a first aspect of the present disclosure, a robot for adjusting a sewing line is provided. The robot includes: a robot arm configured to hold an adjustment tool; and a controller configured to: partially pass the adjustment tool through the line segment along a path defined between the bottom side of the line segment and the outer surface of an object, wherein the sewing line includes a second end and a first end fixed to the object, a plurality of stitches are formed between the first end and the second end across a sewing area on the object, and each stitch includes the line segment, the line segment having a top side and an opposite bottom side; and move the adjustment tool upward away from the outer surface to adjust the spacing between the stitches.

[0006] According to the present invention, the spacing between adjacent sewing stitches is adjusted, so that the joining strength of the seam formed by the stitches can be increased, and the appearance of the sewn product can be improved.

[0007] In some embodiments, the controller may be configured to: determine an adjustment position corresponding to a thread segment of a stitch to be adjusted; move the adjustment tool to a preparation position at a first lateral side of the thread segment, the preparation position being offset from the to-be-sewn position by an offset distance; and move the adjustment tool a first distance from the first lateral side of the thread segment to an opposite second lateral side of the thread segment so that the tool passes through the thread segment, the first distance being greater than the offset distance. With this arrangement, scratches are reduced during the adjustment operation.

[0008] In some embodiments, the robot may further comprise a camera for capturing an image of the object, wherein the adjustment position is determined based on the captured image. By this arrangement, the adjustment position may be easily determined.

[0009] In some embodiments, the controller may be configured to: at the preparation position, press the adjustment tool towards the outer surface in a direction perpendicular to the outer surface to deform the outer surface of the object. With this arrangement, there are no scratches during the adjustment operation.

[0010] In some embodiments, the controller may be configured to: when the adjusting tool is kept in the pressed state, linearly move the adjusting tool from the first lateral side of the wire segment to the first distance to the second lateral side opposite to the wire segment. Through the linear movement of the adjusting tool, the adjusting tool passes through the wire segment from the bottom side without obstruction.

[0011] In some embodiments, the robot may further include a force sensor attached to the robot arm for sensing the contact force between the adjustment tool and the object, wherein the degree of pressing is determined based on the sensed contact force, and the degree of pressing is determined in association with the material of the object. With this arrangement, the contact force can be easily controlled.

[0012] In some embodiments, the adjusting tool may include a pick-up head for penetrating the pin and a curved portion adjacent to the pick-up head, the curved portion being used to hold the wire. By this arrangement, the pick-up head can easily pick up the wire and hold the wire.

[0013] In some embodiments, the controller may be configured to: after the adjustment tool partially passes through the wire segment, adjust the posture of the adjustment tool to keep the wire segment at the curved portion; when the wire segment is kept at the curved portion, move the adjustment tool upward away from the outer surface by a second distance; and stop moving the adjustment tool in response to meeting the requirement. With this arrangement, accidental falling off of the wire can be avoided.

[0014] In some embodiments, the robot may further include a force sensor attached to the robot arm for sensing the force acting on the adjustment tool, wherein the controller is configured to stop moving the adjustment tool in response to the force acting on the adjustment tool being equal to a predetermined threshold, the predetermined threshold being determined in association with the seam pattern of the sewing line. With this arrangement, the spacing is regularly adjusted, and the appearance of the seam can be further improved.

[0015] In some embodiments, the object comprises a cover pre-wrap around a steering wheel, the cover being made of leather, artificial leather, or fabric.

[0016] In a second aspect of the present disclosure, a method for adjusting a sewing line is provided. The method includes: holding an adjustment tool by a robotic arm; partially passing the adjustment tool through the line segment along a path defined between a bottom side of the line segment and an outer surface of an object, wherein the sewing line includes a second end and a first end fixed to the object, and a plurality of stitches are formed on the object across a sewing area between the first end and the second end, each stitch including the line segment, the line segment having a top side and an opposite bottom side; and moving the adjustment tool upward away from the outer surface to adjust the spacing between the stitches.

[0017] In some embodiments, the method may also include: determining, by a controller, an adjustment position corresponding to a line segment of a stitch to be adjusted; moving, by the controller, the adjustment tool to a preparation position at a first lateral side of the line segment, the preparation position being offset from the position to be sewn by an offset distance; and moving, by the controller, the adjustment tool from the first lateral side of the line segment by a first distance, so that the adjustment tool reaches the opposite second lateral side of the line segment, so that the tool passes through the line segment, and the first distance is greater than the offset distance.

[0018] In some embodiments, the method may further include determining the adjusted position and a tangent angle at which the line is tangent to the outer surface based on a captured image captured by a camera.

[0019] In some embodiments, the method may also include: at the preparation position, pressing the adjustment tool toward the outer surface in a direction perpendicular to the outer surface to deform the outer surface of the object, and the extent of the pressing is determined based on the contact force sensed by a force sensor attached to the robot arm.

[0020] In some embodiments, the method may also include: after the adjustment tool partially passes through the line segment, adjusting the posture of the adjustment tool to keep the line segment at the curved portion; with the line segment maintained at the curved portion, moving the adjustment tool upward away from the outer surface; and stopping moving the adjustment tool in response to the force acting on the adjustment tool being equal to a predetermined threshold, wherein the predetermined threshold is determined in association with the seam pattern of the sewing line.

[0021] In some embodiments, the object comprises a cover pre-wrap around a steering wheel, the cover being made of leather, artificial leather, or fabric. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and other purposes, features and advantages of the exemplary embodiments disclosed herein will become more easily understood through the following detailed description with reference to the accompanying drawings. In the accompanying drawings, several exemplary embodiments disclosed herein are shown by way of example and not limitation, in which:

[0023] Figure 1 is a schematic diagram of a robot for sewing an object according to an exemplary embodiment of the present disclosure;

[0024] Figure 2 is a schematic diagram of a robot for adjusting a sewing line according to another exemplary embodiment of the present disclosure;

[0025] Figure 3 is a schematic perspective view showing a state in which sewing stitches are adjusted by an adjusting tool according to an exemplary embodiment of the present disclosure;

[0026] Figure 4 is a schematic perspective view of a portion of a robot for sewing an object according to an exemplary embodiment of the present disclosure, showing a positional relationship between a tool prepared for adjusting a sewn thread and the object;

[0027] Figure 5-Figure 10 is a schematic cross-sectional view showing the principle of how to operate a tool to adjust a sewing line according to an exemplary embodiment of the present disclosure, showing different states of the adjustment tool relative to the sewing line;

[0028] Fig.11 is a flow chart of a method for adjusting a sewing line according to an exemplary embodiment of the present invention.

[0029] Throughout the drawings, the same or similar reference numbers are used to refer to the same or similar elements. DETAILED DESCRIPTION

[0030] The principles of the present disclosure will now be described with reference to several example embodiments shown in the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that these embodiments are described only to facilitate those skilled in the art to better understand and thereby implement the present disclosure, rather than to limit the scope of the present disclosure in any way.

[0031] The terms "including" or "comprising" and their variations should be interpreted as open-ended terms, which mean "including but not limited to". The term "or" should be interpreted as "and / or", unless the context clearly indicates otherwise. The term "based on" should be understood as "based at least in part on". The term "operably" refers to a function, action, movement or state that can be achieved through operation caused by a user or an external mechanism. The terms "one embodiment" and "embodiment" should be understood as "at least one embodiment". The term "another embodiment" should be understood as "at least one other embodiment". The terms "first", "second", etc. may refer to different or the same objects. Other explicit and implicit definitions may be included below. Unless the context clearly indicates otherwise, the definitions of terms are consistent throughout the specification.

[0032] There is an increasing need to automate the assembly process of sewing a cover onto a steering wheel. The present invention proposes a novel robotic system for sewing, which can sew a cover onto a steering wheel. It should be understood that although the present disclosure uses a steering wheel with a cover as an example to illustrate the principles of the present invention, this is merely illustrative and the concept of the present invention can be applied to any other object that needs to be sewn.

[0033] Figure 1 A robotic system 100 for sewing an object is shown. Figure 1 As shown, the robot system 100 includes a support 140 for supporting an object to be sewn (in the example shown, a steering wheel 190), a first robot arm 120, and a second robot arm 130. The object may be a semi-finished product transferred from a previous process, and may include a covering and a blank steering wheel. The covering may be mainly bonded to the blank steering wheel, and the covering should be further sewn according to a predetermined sewing pattern so as to tightly fix the covering to the blank steering wheel. The robot system 100 is configured to perform the above-mentioned sewing operation.

[0034] The robotic system 100 also includes a controller 110 that can communicate with the first robotic arm 120 and the second robotic arm 130 to control their movements to perform sewing operations.

[0035] The robot system 100 may also include one or more cameras 152, 154. Cameras 152 and 154 may be attached to different locations of the robot system to obtain images of the object from different perspectives. The image of the object may be sent to the controller 110. In some embodiments, the controller is configured to visually inspect the object based on the image from the camera, and provide an inspection result indicating whether the object can be sewn by the device before the sewing operation. In some embodiments, the sewing quality after the sewing operation may be provided. In some embodiments, the controller 110 is configured to identify multiple positions to be sewn based on the image from the camera and generate a sewing path. The sewing path determines the sewing pattern based on the input rules of the pattern preparation based on the identified multiple positions to be sewn, and the sewing pattern defines the position to be sewn. According to the sewing path, the controller controls the first robot arm 120 and the second robot arm 130 to perform the sewing operation. Through multiple sewing operations, multiple stitches are automatically formed.

[0036] The first robot arm 120 and the second robot arm 130 are arranged adjacent to the support 140 and thus can approach the steering wheel 190 to perform the sewing operation. The first robot arm 120 and the second robot arm 130 each include a clamp configured to hold the needle 180. The support 140 may include a rotatable shaft so that the position of the steering wheel 190 can be adjusted according to the position of the steering wheel 190 to be sewn.

[0037] The sewing operation of the robot system 100 is described as follows. The first robot arm 120 first holds the needle 180, and the needle 180 is tied with a length of thread. The second robot arm 130 is in a standby position. The controller 110 identifies the position to be sewn and instructs the first robot arm 120 to move to the identified position to be sewn so that the needle 180 penetrates a portion of the steering wheel 190. Then, the controller 110 instructs the second robot arm 130 to hold the penetrated portion of the needle 180, and pull the entire needle 180 out of the steering wheel 190 after the needle 180 is released by the first robot arm 120.

[0038] Through the above process, the needle 180 is inserted into the object, and the needle 180 is further pulled out of the object by the robot system 100. Therefore, a sewn stitch is formed on the object. The above process is repeated several times. A plurality of stitches are formed on the object.

[0039] Although stitches are formed on the object, the stitches are arranged loosely. This means that the spacing of the sewing stitches is not satisfactory and the joint formed by the stitches is loose. Therefore, further action should be taken to tighten the sewing thread so that a firm joint is formed in the sewing area.

[0040] Generally, the cover used to wrap the steering wheel is made of leather, artificial leather, fabric, etc. The sewing line is usually close to the outer surface of the object. Therefore, one problem is how to tighten the sewing line by a robot. In addition, since the cover is usually soft and has a certain degree of flexibility to improve the control feeling of the hand, another problem is how to tighten the sewing line without scratching the outer surface of the cover.

[0041] Therefore, the method for adjusting the stitching line requires that the tool must penetrate the stitching line without scratching. The present disclosure provides a novel robot for adjusting the stitching line, which is capable of adjusting the stitching line on an object made of a flexible material without the risk of scratching.

[0042] like Figure 1 As shown, also refer to Figure 3 , the robot system 100 may further include an adjustment tool 170, which is configured to adjust the spacing of the sewing stitches. The adjustment tool 170 may include a pick-up head, which is configured to pick up the line segment of the sewing stitches and then be moved by the robot arm to apply tension to the sewing stitches. Due to the tension on the sewing stitches, adjacent stitches are close to each other, that is, the spacing of adjacent sewn stitches is adjusted. As a result, the joint strength of the seam joint formed by the stitches can be improved. In addition, the appearance of the sewn product is improved.

[0043] In the exemplary embodiment shown, the adjustment tool 170 is placed near the robot arm 120, and the adjustment tool 170 is interchangeable with the needle 180 carried by the robot arm 120. When an adjustment operation is required, the needle 180 carried by the robot arm 120 can be replaced by the adjustment tool 170 to perform the adjustment operation. This is merely illustrative. In some embodiments, a third robot arm is provided near the object, and the third robot arm can perform the adjustment operation when necessary.

[0044] Figure 2 A robotic system 200 is shown for adjusting sewing stitches 285. Figure 2 As shown, the robot system 200 includes a robot arm 230 and a controller 210. An object 290 to be sewn (e.g., a leather covering) may be placed in a suitable position accessible to the robot arm 220. The controller 210 may communicate with the robot arm 220 to control its movement to perform the sewing operation. The robot arm 220 may include a clamp for holding an adjustment tool 270. Figure 2 As shown, a plurality of sewing stitches are formed on an object 290 by a robotic system.

[0045] The adjustment tool 270 is configured to perform an adjustment operation. The shape of the adjustment tool 270 can hold the thread. In some embodiments, the adjustment tool 270 includes a pick-up head. The shape of the pick-up head is suitable for picking up the thread. The pick-up head may include a fine needle. The fine needle is very sharp and thin and can easily penetrate the thread. This is advantageous when the adjustment tool 270 penetrates the sewing stitches. When the adjustment tool 270 holds the thread and moves upward, the thread remains stationary relative to the adjustment tool 270, so the thread is tensioned. Through the tension, the spacing of the sewing thread is adjusted accordingly. The adjustment tool 270 can be made of suitable materials to form a static friction force relative to the thread, thereby applying it to the thread. In some embodiments, the adjustment tool 270 is made of metal. The thread can be made of chemical fiber, cotton or any other common material.

[0046] In some embodiments, the adjustment tool 270 may include a concave curved portion adjacent to the fine needle. The concave curved portion may be formed as part of the pick-up head. The concave curved portion is configured to securely hold the wire. Once the pick-up head picks up the wire, the wire may move slightly along the curvature of the concave curved portion and may therefore be securely held at the concave curved portion.

[0047] The pick-up head is provided with a fine needle, which is very thin so that the pick-up head can easily pick up and hold the sewing thread. In the example shown, the curved portion can be formed as a concave portion for holding the thread. It should be understood that the shape of the adjustment tool 270 is merely exemplary, and according to the teachings of the present disclosure, the adjustment tool 270 can be formed into any other suitable shape.

[0048] Figure 3 FIG. 2 shows a schematic perspective view of a stitch 285 sewn by a robotic system for sewing an object according to an exemplary embodiment of the present disclosure. Figure 3 As shown, two rows of pre-sewn stitches 282 are pre-formed on the outer surface of object 290, and the two rows of pre-sewn stitches 282 form the sewing area of ​​the object. Each pre-sewn stitch includes a line segment. Sewing stitches 285 are formed by moving the line swing along the path defined between the line segment and the outer surface of object 290, across the line segment of pre-sewn stitches 282. In the example shown, each sewing stitch 285 includes a portion that penetrates the pre-sewn stitch 282 in one row and a portion that penetrates the pre-sewn stitch 282 in another row. Sewing stitches 285 therefore connect two rows of pre-sewn stitches 282 together. In this way, the cover can be sewn on the black steering wheel.

[0049] exist Figure 3In the example shown, two rows of pre-sewn stitches 282 are set on the edge of the covering, and the two edges meet to form a joint. The sewing stitch 285 shown extends across the gap between the two rows of pre-sewn stitches 282. This is merely illustrative and not restrictive. The covering and the pre-sewn stitches 282 can be in any appropriate form. For example, in some embodiments, pre-sewn stitches 282 are not formed on the covering, and multiple holes are formed on the covering. The sewing line 285 may include a second end and a first end fixed to the object. The second end may be a free end. In some embodiments, the second end may be fixed or movable. Multiple stitches are formed between the first end and the second end across the sewing area on the object, and each stitch includes a line segment, and the line segment has a top side and an opposite bottom side.

[0050] It should be understood that the sewing pattern shown is merely illustrative, and the sewing pattern may be any other suitable form, as long as the cover can be sewn on the black steering wheel. In the example shown, two rows of pre-sewn stitches 282 are pre-formed on the object, and the two rows of pre-sewn stitches 282 are used to penetrate the line 285 in order to sew the cover to the black steering wheel. It should be understood that this is merely illustrative, and other measures such as holes may be formed in place of the pre-sewn stitches 282 to facilitate sewing.

[0051] Return to reference Figure 2 , the robot system 200 may also include one or more cameras 252. The camera 252 may be attached to an appropriate location of the robot system and configured to obtain an image of the object. The image of the object may be sent to the controller 210. The controller 210 is configured to identify multiple stitches to be tensioned, i.e., multiple line segments of the sewing line 285, based on the image from the camera. After the adjustment tool 270 passes through the bottom side of each selected stitch to be adjusted, the adjustment tool 270 may be pulled upward so that tension is applied to the sewing line 285. The sewing line 285, in particular adjacent sewing lines, is tensioned with a tensile force. Through the tensioning operation, the sewing line 285 may be tightened, thereby forming a secure sewing joint.

[0052] Figure 4 is a schematic perspective view of a portion of a robot for sewing an object according to an exemplary embodiment of the present disclosure, illustrating a positional relationship between a tool prepared for adjusting a sewn thread and the object.

[0053] Figure 4 yes Figure 3 , and shows the positional relationship between the adjustment tool 270 held by the robot arm 220 and the object to be sewn 290. Figure 4As shown, object 290 includes a flexible outer surface 292. Flexible outer surface 292 may be provided with pre-sewn stitches 282. Sewn stitches 285 are formed by penetrating pre-sewn stitches 282.

[0054] like Figure 4 As shown, the adjustment tool 270 is held by the robot arm 220 and can be moved by the robot arm 220. The object 290 has a plurality of line segments of the sewing line 285. The position of the adjustment tool 270 is represented by P(x, y, z), wherein x, y, z represent coordinates in a coordinate system, the xy plane represents the horizontal plane where the position Q to be tensioned on the object 290 (which corresponds to the line section of the sewing line 285) is located, and the z-axis represents the direction perpendicular to the xy plane. It should be understood that P(x, y, z) is merely illustrative and the position of the adjustment tool 270 may be represented by any other appropriate coordinate system. Figure 4 , the coordinates of the adjustment tool 270 are located at position P (x, y, z) and are offset by Δx, Δy, Δz relative to position Q. The controller can use these parameters to control the robotic arm 220 to move the adjustment tool 270, in particular the adjustment tool 270, to the appropriate position to perform the tensioning operation.

[0055] Figure 5-Figure 10 2 is a schematic cross-sectional process view illustrating the principle of how to operate the adjustment tool 270 to perform an adjustment operation according to an exemplary embodiment of the present disclosure, showing different states of the adjustment tool 270 relative to the position Q to be adjusted. Figure 5-Figure 10 Similar to Figure 4 , but a plan view of the yz plane is shown, in which the relative positions of the adjustment tools 270 are shown to better illustrate their positional relationship.

[0056] exist Figure 5 In the embodiment, the adjustment tool 270 is in an offset position before the adjustment operation. Figure 5 As shown, also refer to Figure 4 The object 290 includes a flexible outer surface 292 and a plurality of stitching line segments (such as Figure 5 ).

[0057] Each stitching line segment includes a line segment 285 including a top side 287 and an opposite bottom side 288 facing an outer surface 292. To ensure that there are no scratches, the adjustment tool 270 is controlled to pass through the line segment 285 along a path defined between the bottom side 288 of the line segment 285 and the outer surface 292 of the object 290.

[0058] Assume that the adjustment tool 270 will be Figure 5The position represented by position Q in FIG. 2 passes through line segment 285. Position Q is first determined, for example by camera 252. The robot also knows the position P of adjustment tool 270. Therefore, the controller knows the relative relationship between adjustment tool 270 and position Q.

[0059] Once the above parameters are determined, the robotic arm 220 is lowered onto the object 290 and the adjustment tool 270 is moved a first distance from a first lateral side of the wire segment 285 to an opposite second lateral side of the wire segment so that the adjustment tool 270 passes through the wire segment. In this way, the adjustment tool 270 can pass through the wire segment 285 from the bottom side with fewer or no scratches. In some embodiments, the first distance is greater than the offset distance. This ensures that the adjustment tool 270 does pass through the wire segment 285 from the bottom side.

[0060] The adjustment tool 270 includes a pick-up head shaped to pick up the thread when the adjustment tool 270 passes through the thread section 285 from the bottom side. In some embodiments, the pick-up head is provided with a fine needle that is very fine so that the pick-up head can easily pick up and hold the sewing thread.

[0061] In some embodiments, Figure 6 As shown, in the preparation position, the adjustment tool 270 is further pressed toward the outer surface 292 in a direction perpendicular to the outer surface 292 to deform the outer surface 292 of the object. In some embodiments, the pick-up head may further include a straight portion adjacent to the fine needle. Through this straight portion, the contact force of the adjustment tool 270 on the outer surface 292 can be stabilized. It should be understood that this is merely illustrative.

[0062] In some embodiments, Figure 7 As shown, when the adjustment tool 270 is pressed toward the outer surface 292 in a direction perpendicular to the outer surface 292, the adjustment tool 270, at least its pick-up head, can pass between the bottom side 288 of the wire segment 285 and the outer surface 292 of the object 290 without obstruction.

[0063] By deforming the outer surface 292 of the object, the scratches caused by the adjustment tool 270 can be completely eliminated. It should be understood that this is merely illustrative and not restrictive. In some embodiments, the step of pressing the adjustment tool 270 can be omitted. For example, when a slight gap is initially formed between the line segment of the sewing thread and the outer surface 292 of the object and the adjustment tool 270 can pass through the slight gap, it is not necessary to press the adjustment tool 270.

[0064] In some embodiments, the robot may further include a force sensor attached to the robot arm. The force sensor is configured to sense the contact force between the adjustment tool 270 and the object. In this way, the degree of the pressing is determined based on the sensed contact force. In some embodiments, the degree of pressing is determined in association with the material properties of the object (e.g., the hardness of the covering). Using the force sensor, the force used to deform the outer surface 292 of the object can be accurately controlled.

[0065] like Figure 7 As shown, the adjustment tool 270 is linearly moved a first distance from a first lateral side of the wire segment to an opposite second lateral side of the wire segment. The adjustment tool 270 passes through the wire without obstruction. Due to the shape of the adjustment tool 270, the adjustment tool 270 can easily pick up the wire segment 285.

[0066] In some embodiments, Figure 8 As shown, the posture of the adjustment tool 270 can be adjusted so that the adjustment tool 270 is tilted slightly upward away from the outer surface 292 after moving the first distance. For example, the posture of the adjustment tool 270 can be adjusted by rotating the adjustment tool 270, such as Figure 8 In this way, the wire 285 can be firmly held on the adjustment tool 270 to avoid accidental separation from the adjustment tool 270.

[0067] In some embodiments, Fig. 9 As shown, in the adjusted posture, the adjustment tool 270 is moved a second distance in a direction away from the outer surface 292 of the object. By moving the adjustment tool 270, tension is applied to the sewing line 285, and the sewing line 285 in turn tightens the sewing stitches, especially the adjacent stitches adjacent to the position Q. Therefore, the spacing between adjacent stitches can be appropriately adjusted. It should be understood that in the example shown, the pulling direction is perpendicular to the outer surface 292 of the object. This is merely illustrative, and the pulling direction or tensioning direction can be any other suitable direction, as long as the line 285 does not fall off from the adjustment tool 270.

[0068] In some embodiments, a force sensor can be attached to the robot arm 220 for sensing the force acting on the adjustment tool 270. In response to the force being equal to a predetermined threshold, the pulling movement of the adjustment tool 270 is stopped. The predetermined threshold can be determined in association with the seam pattern of the sewing line. The seam pattern can determine the appearance of the final seam and the tightness requirement of the seam. Using the force sensor, it is ensured that a fixed force is applied to the adjustment tool 270, and the appearance of the final seam is further improved. The predetermined threshold can be obtained from experience or trial testing.

[0069] In some embodiments, Fig.10As shown, after adjusting or tensioning the line 285 by the adjustment tool 270, the adjustment tool 270 can be retracted from the line 285, for example, by rotating toward the outer surface 292 of the object. Then, the adjustment tool 270 can be moved to the initial standby position and prepared for another adjustment cycle. For the entire seam, multiple tensioning operations are performed every several stitches, so the entire joint sewn seam can be evenly tightened to the desired tension appearance in an automatic manner.

[0070] In the exemplary embodiment shown, the adjustment tool 270 includes a pick-up head 272, which is shaped to pick up the wire. In some embodiments, the adjustment tool does not include a pick-up head. In this case, before the adjustment tool passes through the wire, the posture of the adjustment tool can be adjusted so that the tip of the adjustment tool is tangent to the outer surface of the object. This means that when the adjustment tool 270 penetrates the object or passes through the wire segment 285 from the bottom side of the wire segment 285, the direction of the tip of the adjustment tool 270 is always tangent to the outer surface of the object at position Q. Through these measures, the orientation of the adjustment tool 270 can be accurately controlled, and the scratches caused by the adjustment tool 270 are reduced.

[0071] Fig.11 is a flow chart of a method 300 for adjusting a sewing line according to an exemplary embodiment of the present disclosure. Fig.11 As shown, method 300 includes the following actions. In frame 302, the adjustment tool is first held by the robot arm. In frame 304, the adjustment tool is partially passed through the line segment along the path defined between the bottom side of the line segment and the outer surface of the object. The sewing line includes a second end and a first end fixed to the object, and a plurality of stitches are formed between the first end and the second end across the sewing area on the object, each stitch including a line segment with a top side and an opposite bottom side. In frame 306, the adjustment tool is moved upward away from the outer surface to adjust the spacing between the stitches. In this way, the spacing between the stitches can be easily adjusted.

[0072] In some embodiments, the method may further include the following actions. The controller determines an adjustment position corresponding to the thread segment of the stitch to be adjusted. The adjustment tool is moved to a preparation position at a first lateral side of the thread segment, the preparation position being offset from the position to be sewn by an offset distance. The adjustment tool is moved a first distance from the first lateral side of the thread segment to an opposite second lateral side of the thread segment so that the tool passes through the thread segment, the first distance being greater than the offset distance.

[0073] In some embodiments, the method may further include determining an adjustment position and a tangent angle at which the line is tangent to the outer surface based on a captured image captured by the camera.

[0074] In some embodiments, the method may further include pressing the adjustment tool toward the outer surface in a direction perpendicular to the outer surface at the preparation position to deform the outer surface of the object, and the degree of pressing is determined based on the contact force sensed by the force sensor attached to the robot arm.

[0075] In some embodiments, the method may further include: adjusting the posture of the adjusting tool to keep the line segment at the curved portion after the adjusting tool partially passes through the line segment; moving the adjusting tool upward away from the outer surface with the line segment maintained at the curved portion; and moving the adjusting tool upward in response to the force acting on the adjusting tool being equal to a predetermined threshold, wherein the predetermined threshold is determined in association with the seam pattern of the sewing line.

[0076] In some embodiments, the object includes a cover pre-wrap around a steering wheel, the cover made of leather, artificial leather, fabric, or any other suitable material having a flexible and smooth outer surface.

[0077] By the teaching provided in the above description and the related drawings, those skilled in the art to which the present disclosure belongs will understand many modifications and other embodiments of the present disclosure given herein. Therefore, it should be understood that the embodiments of the present disclosure are not limited to the specific embodiments of the present disclosure, and modifications and other embodiments are intended to fall within the scope of the present disclosure. In addition, although exemplary embodiments are described in the context of some illustrative combinations of components and / or functions in the above description and the related drawings, it should be appreciated that different combinations of components and / or functions can be provided in alternative embodiments without departing from the scope of the present disclosure. In this regard, for example, it is expected that other combinations of components and / or functions different from those explicitly described above will also fall within the scope of the present disclosure. Although specific terms are used here, they are only used in general and descriptive senses, rather than restrictive.

Claims

1. A robot for adjusting a sewing line (285), comprising: a robotic arm (230) configured to hold an adjustment tool (270); as well as The controller (210) is configured to: The adjustment tool (270) is partially passed through the wire segment along a path defined between the bottom side of the wire segment and the outer surface (292) of the object (290), wherein The sewing thread (285) includes a first end secured to the object (290) and a second end, a plurality of stitches formed on the object (290) between the first end and the second end across a sewing area, and each stitch includes the thread segment having a top side and an opposite bottom side; as well as The adjustment tool (270) is moved upwardly and away from the outer surface (292) to adjust the spacing between the pins.

2. The robot according to claim 1, wherein the controller (210) is configured to: determining an adjustment position corresponding to a line segment of the stitch to be adjusted; moving the adjustment tool (270) to a preparation position at a first lateral side of the line segment, the preparation position being offset from a to-be-sewn position by an offset distance; and The adjustment tool (270) is moved a first distance from the first lateral side of the wire segment to an opposite second lateral side of the wire segment such that the tool (270) passes through the wire segment, the first distance being greater than the offset distance.

3. The robot according to claim 2, further comprising a camera for capturing an image of the object (290), wherein the adjusted position is determined based on the captured image.

4. The robot according to claim 2, wherein the controller (210) is configured to: At the preparation position, the adjustment tool (270) is pressed toward the outer surface (292) in a direction perpendicular to the outer surface (292) to deform the outer surface (292) of the object (290).

5. The robot according to claim 4, wherein the controller (210) is configured to: With the adjustment tool (270) maintained in a pressed state, the adjustment tool (270) is linearly moved the first distance from the first lateral side of the wire segment to the opposite second lateral side of the wire segment.

6. The robot according to claim 5 further includes a force sensor, which is attached to the robot arm (230) and is used to sense the contact force between the adjustment tool (270) and the object (290), wherein the degree of pressing is determined based on the sensed contact force, and the degree of pressing is determined in association with the material of the object (290).

7. The robot according to any one of claims 1-6, wherein the adjustment tool (270) includes a pick-up head (272) for penetrating the stitch and a curved portion adjacent to the pick-up head (272), the curved portion for holding the wire.

8. The robot according to claim 7, wherein the controller (210) is configured to: After the adjusting tool (270) partially passes through the wire segment, adjusting the posture of the adjusting tool (270) to hold the wire segment at the curved portion; With the wire segment maintained at the curved portion, moving the adjustment tool (270) upwardly a second distance away from the outer surface (292); and In response to the requirement being met, movement of the adjustment tool (270) is stopped.

9. The robot according to claim 8, further comprising a force sensor attached to the robot arm (230) for sensing a force acting on the adjustment tool (270), The controller (210) is configured to stop moving the adjustment tool (270) in response to the force acting on the adjustment tool (270) being equal to a predetermined threshold, wherein the predetermined threshold is determined in association with a seam pattern of the sewing line (285).

10. The robot according to any one of claims 1-6 and 8-9, wherein the object (290) comprises a covering pre-wound around a steering wheel, the covering being made of leather, artificial leather or fabric.

11. A method for adjusting a sewing line (285), comprising: holding an adjustment tool (270) by a robotic arm (230); Passing the adjustment tool (270) partially through the thread segment along a path defined between a bottom side of the thread segment and an outer surface (292) of an object (290), wherein the sewing thread (285) includes a first end secured to the object (290) and a second end, a plurality of stitches being formed on the object (290) between the first end and the second end across a sewing area, and each stitch including the thread segment, the thread segment having a top side and an opposing bottom side; as well as The adjustment tool (270) is moved upwardly and away from the outer surface (292) to adjust the spacing between the pins.

12. The method according to claim 11, further comprising: The controller (210) determines the adjustment position corresponding to the line segment of the stitch to be adjusted; The controller (210) moves the adjustment tool (270) to a preparation position located at a first lateral side of the line segment, the preparation position being offset from a to-be-sewn position by an offset distance; as well as The controller (210) moves the adjustment tool (270) a first distance from the first lateral side of the wire segment to the opposite second lateral side of the wire segment so that the tool (270) passes through the wire segment, and the first distance is greater than the offset distance.

13. The method according to claim 12, further comprising: The adjusted position and the tangent angle at which the line is tangent to the outer surface (292) are determined based on a captured image captured by a camera.

14. The method according to claim 12, further comprising: At the preparation position, the adjustment tool (270) is pressed toward the outer surface (292) in a direction perpendicular to the outer surface (292) to deform the outer surface (292) of the object (290), and the degree of pressing is determined based on a contact force sensed by a force sensor attached to the robot arm (230).

15. The method according to claim 12, further comprising: After the adjusting tool (270) partially passes through the wire segment, adjusting the posture of the adjusting tool (270) to hold the wire segment at the curved portion; With the wire segment held at the curved portion, moving the adjustment tool (270) upwardly away from the outer surface (292); as well as The movement of the adjustment tool (270) is stopped in response to the force acting on the adjustment tool (270) being equal to a predetermined threshold, the predetermined threshold being determined in association with the seam pattern of the stitch line (285).

16. The method according to any one of claims 11-15, wherein the object (290) comprises a covering pre-wound around a steering wheel, the covering being made of leather, artificial leather or fabric.

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