An automatic positioning and grasping device and its control method

Abstract

This invention relates to the field of garment machinery technology, specifically disclosing an automatic positioning and gripping device and its control method. The automatic positioning and gripping device includes a lifting unit and a gripping unit. The lifting unit includes a lifting platform and a feeding tray. The feeding tray is installed on the lifting platform and can move along a third direction. The feeding tray is used for stacking cut pieces. The gripping unit includes a stacking platform and a feeding and gripping mechanism. The feeding and gripping mechanism includes a lower support plate and an upper support plate. The lower support plate is disposed on the stacking platform and can move along a first direction. The upper support plate is disposed on the lower support plate and can move along a second direction. The upper support plate is provided with a gripper assembly. The gripper assembly is equipped with a photoelectric distance sensor for detecting and positioning the cut piece stack in a third direction and a camera module for positioning the edge of the uppermost cut piece of the cut piece stack. This invention can effectively avoid the problem of the gripper gripping the fabric crookedly or missing the target area due to the offset position of the cut piece stack or the disordered stacking during feeding, thereby improving production efficiency.

Description

Technical Field

[0001] This invention relates to the field of garment machinery technology, and in particular to an automatic positioning and gripping device and its control method. Background Technology

[0002] Currently, garments are generally formed by overlapping cut pieces (top and bottom pieces) and sewing them together using a sewing machine. This process is typically done manually, with a low level of automation. Additionally, there are automated feeding mechanisms on the market designed to replace manual labor in feeding stacks of cut pieces. To ensure feeding accuracy, these mechanisms require the stacks of cut pieces to be laid flat before feeding. However, in actual production, human error or other factors can cause the fabric stacks to shift or become disorganized during feeding, leading to problems such as the gripper grasping the fabric incorrectly or missing its target. This not only reduces production efficiency but also lowers the quality of the finished garment. Summary of the Invention

[0003] The technical problem to be solved by this invention is: how to avoid the problem of the gripper grabbing the fabric crookedly or missing the target area due to human factors or other factors causing the fabric stack to shift or become scattered during feeding.

[0004] To address the aforementioned technical problems, the present invention provides an automatic positioning and grasping device, comprising:

[0005] A lifting unit, comprising a lifting platform and a loading tray, wherein the loading tray is mounted on the lifting platform and is movable in a third direction, and the loading tray is used for stacking cut pieces; and

[0006] The gripping unit includes a stacking platform and a feeding gripping mechanism. The feeding gripping mechanism includes a lower support plate and an upper support plate. The lower support plate is disposed on the stacking platform and can move along a first direction. The upper support plate is disposed on the lower support plate and can move along a second direction. The upper support plate is provided with a gripper assembly. The gripper assembly is provided with a photoelectric distance sensor for detecting and positioning the cut piece stack in a third direction and a camera module for positioning the edge of the uppermost cut piece of the cut piece stack.

[0007] More preferably, the gripper assembly includes a fixed gripper and a movable gripper. The fixed gripper is fixed to the upper support plate, and the movable gripper is symmetrically arranged on both sides of the fixed gripper. The movable gripper can move along a second direction, and the photoelectric distance sensor and the camera module are both located on the movable gripper.

[0008] More preferably, the camera module includes:

[0009] A light source emitting unit is used to project a light source onto the edge of the topmost layer of cut pieces in the stack; and

[0010] A camera is used to detect the transition point generated by the light source projection of the light source emitting unit at the edge of the uppermost cut piece.

[0011] More preferably, the projection path of the light source emitting unit is not perpendicular to the loading tray, and the optical axis of the camera is perpendicular to the loading tray.

[0012] More preferably, the light emission direction of the photoelectric distance sensor is perpendicular to the feeding tray.

[0013] The present invention also provides a control method for an automatic positioning and grasping device, comprising the following steps:

[0014] Calculate the hem width of the cut piece based on the CAD model of the cut piece;

[0015] Adjust the spacing between the movable grippers on both sides according to the width of the hem of the cut piece;

[0016] Set the alignment height of the loading pallet;

[0017] Adjust the height of the feeding tray to the alignment height, and adjust the position of the movable gripper according to the feedback value of the photoelectric distance sensor to align the stack of cut pieces;

[0018] Adjust the position of the active gripper according to the feedback value from the camera module, and align it with the topmost cut piece to be grabbed;

[0019] Grab the cut piece and complete the feeding process.

[0020] More preferably, the steps of adjusting the height of the feeding tray to the alignment height and adjusting the position of the movable gripper according to the feedback value of the photoelectric distance sensor to align the stack of cut pieces include:

[0021] The distance from the photoelectric distance sensor to the loading tray when the loading tray is at its lowest height is set as a threshold.

[0022] Obtain the feedback values ​​from the photoelectric distance sensors corresponding to the movable grippers on both sides;

[0023] The feedback values ​​from the photoelectric distance sensors on both sides are compared with the threshold.

[0024] More preferably, the step of comparing the feedback values ​​of the photoelectric distance sensors on both sides with a threshold includes:

[0025] If the feedback value of the photoelectric distance sensor on one side is less than or equal to the threshold, and the feedback value of the photoelectric distance sensor on the other side is greater than the threshold, then the gripping unit moves a distance D along the second direction toward the side where the feedback value of the photoelectric distance sensor is less than or equal to the threshold, and repeatedly acquires the feedback values ​​of the photoelectric distance sensors corresponding to the two active grippers.

[0026] If the feedback values ​​of the photoelectric distance sensors on both sides are greater than the threshold, the alignment is successful and the process proceeds to the next stage.

[0027] If the feedback values ​​of the photoelectric distance sensors on both sides are less than or equal to the threshold, the alignment fails, the system stops and an alarm is triggered.

[0028] More preferably, the step of adjusting the position of the movable gripper according to the camera module feedback value and aligning it with the topmost cut piece to be gripped includes:

[0029] The camera module is calibrated and the coordinates of the target point at the alignment height are obtained;

[0030] Acquire one image from each of the two cameras, determine the coordinates of the transition point of the first light source projection in the two images, and obtain the edge point of the topmost cropped piece.

[0031] Calculate the distance between each of the movable grippers and the target point to obtain the change in the distance between the two movable grippers, and adjust the distance between the movable grippers on both sides according to the change;

[0032] Calculate and obtain the moving distance of the feeding and gripping mechanism.

[0033] More preferably, the step of calibrating the camera module and obtaining the target point coordinates at the alignment height includes:

[0034] Raise the loading tray until the top layer of cut pieces contacts the fixed gripper, then lower the loading tray by a height H to obtain the alignment height;

[0035] The distance that the movable gripper should move is calculated based on the target point and the transition point of the first light source projection in the camera when the movable gripper is aligned with the edge of the cut piece.

[0036] Compared with the prior art, the automatic positioning and grasping device and its control method provided by this invention have the following advantages:

[0037] An automatic positioning and gripping device stacks cut pieces on a feeding tray. A lifting platform raises the stack of cut pieces to a higher level, allowing the gripper assembly to grasp the top layer of cut pieces. By setting a lower support plate and an upper support plate, the gripper assembly can be adjusted and moved along a first direction and a second direction, improving the gripping accuracy of the top layer of cut pieces. In addition, by setting a photoelectric distance sensor and a camera module, the gripping accuracy of the top layer of cut pieces can be further improved, ensuring the processing quality of the garment. This device also avoids problems such as the gripper grasping the fabric crookedly or missing the target area due to human factors or other factors that cause the cut piece stack to shift or become scattered during feeding.

[0038] A control method for an automatic positioning and gripping device includes: calculating the hem width of the cut piece based on a CAD model of the cut piece; adjusting the spacing between the movable grippers on both sides according to the hem width; adjusting the height of the loading tray to the alignment height; adjusting the position of the movable grippers according to the feedback value of the photoelectric distance sensor to align with the stack of cut pieces; and adjusting the position of the movable grippers according to the feedback value of the camera module to align with the topmost cut piece to be gripped. After aligning the loading tray, the automation and stability of the cut piece stack loading are improved. Combined with the photoelectric distance sensor and camera module, it enables automatic and accurate gripping of the topmost cut piece in a stack of cut pieces, avoiding problems such as misalignment or missing the target. Attached Figure Description

[0039] Figure 1 This is a perspective view of an automatic positioning and grasping device according to the present invention.

[0040] Figure 2 This is a front view of an automatic positioning and grasping device according to the present invention.

[0041] Figure 3 This is a structural diagram of the gripper assembly described in this invention.

[0042] Figure 4 This is a flowchart of a control method for an automatic positioning and grasping device according to the present invention.

[0043] In the diagram: 1. Lifting unit; 11. Lifting platform; 12. Loading pallet;

[0044] 2. Gripping unit; 21. Stacking platform; 22. Feeding and gripping mechanism; 221. Lower support plate; 222. Upper support plate; 223. Gripper assembly; 2231. Fixed gripper; 2232. Movable gripper; 2232a. Photoelectric distance sensor; 2232b. Laser emitter; 2232c. Camera. Detailed Implementation

[0045] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0046] In the description of this invention, it should be understood that the terms "upper", "lower", "left", "right", "between", "both sides", "near", "far away", etc., used in this invention to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0047] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly, for example, referring to a fixed connection, a detachable connection, or an integral connection; a mechanical connection or an electrical connection; a direct connection or an indirect connection via an intermediate medium; or a connection within two components. Those skilled in the art will understand the specific meaning of these terms in this invention based on the specific circumstances.

[0048] Example 1

[0049] like Figure 1 As shown, this embodiment 1 provides an automatic positioning and gripping device, which includes a lifting unit 1 and a gripping unit 2. The lifting unit 1 is used to stack cut pieces and can realize the overall lifting and lowering of the cut piece stack, while the gripping unit 2 is used to grip the uppermost cut piece in the cut piece stack for sewing.

[0050] Please continue to combine Figure 1 In this embodiment, the lifting unit 1 includes a lifting platform 11 and a feeding tray 12. The feeding tray 12 is installed on the lifting platform 11 and can move along the third direction Z. That is, the feeding tray 12 can be lifted and lowered under the action of the lifting platform 11, thereby realizing the overall lifting and lowering of the cut piece stack. The feeding tray 12 is used to stack cut pieces, and the lifting platform 11 can adapt to cut piece stacks of different heights.

[0051] In this embodiment, the gripping unit 2 includes a stacking platform 21 and a feeding gripping mechanism 22. Preferably, the height of the plane containing the upper surface of the stacking platform 21 is greater than or equal to the height of the lifting platform 11, and the feeding gripping mechanism 22 is installed on the upper surface of the stacking platform 21. In use, the feeding gripping mechanism 22 is used to grip the uppermost piece of cut fabric in the stack of cut fabric on the lifting platform 11 and move it to the stacking platform 21 for processing and tailoring.

[0052] In this embodiment, the feeding and gripping mechanism 22 includes a lower support plate 221 and an upper support plate 222. The lower support plate 221 is mounted on the stacking platform 21 and can move along the first direction X. The upper support plate 222 is mounted on the lower support plate 221 and can move along the second direction Y. A gripper assembly 223 is mounted on the upper support plate 222. Thus, the lower support plate 221 can drive the entire feeding and gripping mechanism 22 to move along the first direction X, while the upper support plate 222 can drive the gripper assembly 223 to move along the second direction Y. This allows the gripper assembly 223 to have multiple degrees of freedom, namely, it can adjust the front, back, left, and right positions of the gripper assembly 223. It can also adapt to the width of the cut pieces and the placement position of the cut pieces, so as to improve the positioning and gripping accuracy and ensure the subsequent processing quality.

[0053] It should be noted that in the above examples, the first direction X, the second direction Y, and the third direction Z are only used to indicate the azimuth or positional relationship based on the azimuth or positional relationship shown in the attached drawings; for example... Figure 1 As shown, the first direction X represents the length direction of the device, the second direction Y represents the width direction of the device, and the third direction Z represents the height direction of the device. These directions should not be construed as limitations on the present invention.

[0054] In this embodiment, as Figure 2-3 As shown, the gripper assembly includes a fixed gripper 2231 and a movable gripper 2232. The fixed gripper 2231 is fixed to the upper support plate 222. To ensure the accuracy of positioning and gripping, the movable gripper 2232 is symmetrically arranged on both sides of the fixed gripper 2231. That is, the three grippers can simultaneously position and grip the uppermost piece of fabric, reducing the wrinkling and deformation of the fabric during gripping, while ensuring the stability of gripping, thereby improving the subsequent processing quality.

[0055] In addition, to facilitate the adjustment of the spacing between the grippers to adapt to the positioning and gripping of cut pieces of different sizes, the movable gripper 2232 is set to be able to move along the second direction Y, that is, the spacing between the left and right movable grippers 2232 can be adjusted, which can achieve self-adaptation to the width of the cut piece and the placement position of the cut piece.

[0056] In this embodiment, the gripper assembly is equipped with a photoelectric distance sensor for detecting and positioning the stack of cut pieces in a third-dimensional direction, and a camera module for positioning the edge of the top layer of cut pieces in the stack. Preferably, both the photoelectric distance sensor 2232a and the camera module are located on the movable gripper 2232. The photoelectric distance sensor and the camera module can further improve the gripping accuracy of the top layer of cut pieces, ensure the processing quality of the garment, and avoid the problem of the gripper gripping the fabric crookedly or missing the target due to the positional shift or scattered stacking of the cut pieces caused by human factors or other factors during feeding.

[0057] It should be noted that, in order to ensure positioning and grasping accuracy, photoelectric distance sensors 2232a and camera modules are installed on both sides of the movable gripper 2232.

[0058] In this embodiment, the camera module includes a light source emitting unit and a camera 2232c. The light source emitting unit is used to emit a light source projection onto the edge of the uppermost layer of the cut pieces in the stack, and the camera 2232c is used to detect the transition point generated by the light source projection of the light source emitting unit at the edge of the uppermost layer of the cut pieces.

[0059] In a preferred embodiment, the light source emitting unit is preferably a laser emitter 2232b. Specifically, the laser emitter 2232b is used to emit a straight line projection line at the edge of the uppermost layer of the cut pieces in the stack of cut pieces. The camera 2232c is used to detect the transition point generated by the projection line of the laser emitter at the edge of the cut piece. The transition point refers to the discontinuity point formed by the straight line projection line at the junction of the upper and lower layers of cut pieces.

[0060] In the above embodiment, taking the movable gripper 2232 on one side as an example, it is equipped with a photoelectric distance sensor 2232a. The light emission direction of the photoelectric distance sensor 2232a is perpendicular to the plane of the feeding tray 12 and downwards, which is used to locate the approximate position of the cut piece stack. The laser emitter 2232b and the camera 2232c form a camera module. The laser emitter 2232b projects a line at an inclined angle (i.e., non-perpendicular state), so that the projected line produces discontinuities at the edge of the cut piece. The optical axis of the camera 2232c is perpendicular to the feeding tray 12 and downwards, which is used to locate the position of the left and right edges of the top layer of cut pieces in the cut piece stack.

[0061] In other embodiments, the light source emitting unit can also be a visible light surface light source, and its installation method is the same as that of the laser emitter 2232b, that is, the installation position and illumination direction are similar to those of the laser emitter 2232b, which will not be described again. When a visible light surface light source is used, a shadow can be formed at the edge of the cut piece, enhancing the visual characteristics of the cut piece edge. At this time, the target detected by the camera 2232c changes from the point feature of the "discontinuity point" to the two-dimensional curve of the "cut piece edge", that is, the transition point at this time is the curve.

[0062] In the preferred embodiment, it should be noted that the above-mentioned laser emitter 2232b and camera 2232c, or visible light surface light source and camera 2232c, constitute a camera module. For those skilled in the art, several improvements and substitutions can be made without departing from the technical principle of the present invention. For example, a profilometer, line structure light, or other sensors can be used to replace the camera module of this embodiment. Although the cost of profilometers, line structure light, and other sensors is high, these improvements and substitutions should also be considered within the scope of protection of the present invention.

[0063] In summary, this embodiment provides an automatic positioning and gripping device that stacks cut pieces on a feeding tray 12. The lifting platform 11 raises the stack of cut pieces to a higher height, allowing the gripper assembly 223 to grip the top layer of cut pieces. By setting the lower support plate 221 and the upper support plate 222, the gripper assembly 223 can be adjusted along the first direction X and the second direction Y, improving the gripping accuracy of the top layer of cut pieces. In addition, by setting a photoelectric distance sensor and a camera module, the gripping accuracy of the top layer of cut pieces can be further improved, ensuring the processing quality of the garment. It can also avoid the problem of the gripper gripping the fabric crookedly or missing the target due to the positional deviation or scattered stacking of cut pieces caused by human factors or other factors during feeding.

[0064] Example 2

[0065] This embodiment 2 provides a control method for an automatic positioning and grasping device, which is based on the automatic positioning and grasping device of embodiment 1, such as... Figure 4 As shown, the control method for the automatic positioning and grasping device includes the following steps:

[0066] Step S1: Calculate the hem width of the cut piece based on the CAD model of the cut piece;

[0067] Step S2: Adjust the distance between the movable grippers on both sides according to the width of the hem of the cut piece;

[0068] Set the alignment height of the loading pallet;

[0069] Step S3: Adjust the height of the feeding tray to the alignment height, and adjust the position of the movable gripper according to the feedback value of the photoelectric distance sensor to align the stack of cut pieces;

[0070] Step S4: Adjust the position of the active gripper according to the feedback value of the camera module, and align it with the topmost cut piece to be grasped;

[0071] Step S5: Grab the cut piece and complete the feeding.

[0072] It should be noted that before proceeding to step S1, the automatic positioning and gripping device should be initialized. Initialization should include hardware reset, adjustment of the distance between the two movable grippers, and return of the loading tray 12 to the zero position.

[0073] The aforementioned hardware reset should include actions such as zero-position calibration and repositioning.

[0074] The above adjustment of the distance between the movable grippers on both sides refers to setting the distance between the movable grippers on the left and right sides to L based on the hem width value of the fabric piece entered by the user or the hem width value of the fabric piece automatically parsed from the CAD template (both referred to as L).

[0075] The aforementioned return of the loading pallet 12 to the zero position means that the loading pallet 12 is lowered to the lowest height under the action of the lifting platform 11.

[0076] In step S3 above, adjusting the height of the feeding tray to the alignment height and adjusting the position of the movable gripper according to the feedback value of the photoelectric distance sensor to align the stack of cut pieces includes:

[0077] S31: Set the distance from the photoelectric distance sensor to the loading tray 12 when the loading tray 12 is at its lowest height as a threshold;

[0078] S32: Obtain the feedback values ​​of the photoelectric distance sensors corresponding to the movable grippers on both sides;

[0079] S33: Compare the feedback values ​​of the photoelectric distance sensors on both sides with the threshold.

[0080] In step S33, the output logic of the photoelectric distance sensor is set as follows: a high level indicates that the distance of the measuring point is less than or equal to the threshold, and a low level indicates that the distance of the measuring point is greater than the threshold; the threshold is set as the distance from the photoelectric distance sensor to the feeding tray when the feeding tray is at its lowest height.

[0081] In step S33 above, the step of comparing the feedback values ​​of the photoelectric distance sensors on both sides with the threshold includes:

[0082] S331: If the feedback value of the photoelectric distance sensor on one side is less than or equal to the threshold (i.e., the feedback value is high level), and the feedback value of the photoelectric distance sensor on the other side is greater than the threshold (i.e., the feedback value is low level), then the grasping unit 2 moves a distance D along the second direction Y toward the side where the feedback value of the photoelectric distance sensor is less than or equal to the threshold, and repeats steps S32 and S33.

[0083] S332: If the feedback values ​​of the photoelectric distance sensors on both sides are greater than the threshold (i.e., the feedback value is low level), then the alignment is successful and proceed to the next stage;

[0084] S333: If the feedback values ​​of the photoelectric distance sensors on both sides are less than or equal to the threshold (i.e., the feedback value is high level), the alignment fails, the system stops and alarms.

[0085] In the above example, to ensure control accuracy, the distance D is generally set to a very small value; preferably, D ≤ 0.1 mm.

[0086] It should be noted that the above steps target the left and right edges of the entire stack of cut pieces, not just the left and right edges of the topmost piece to be grasped. This is impossible because the distance detection accuracy of the photoelectric distance sensor is insufficient to detect the thickness of a single layer of cut pieces. Furthermore, the loading tray only has the ability to move in the Z-direction; horizontal alignment is handled by the loading and gripping mechanism.

[0087] In step S4 above, the step of adjusting the position of the active gripper according to the camera module feedback value and aligning it with the topmost cut piece to be grasped includes:

[0088] S41: Calibrate the camera module and obtain the target point coordinates at the alignment height;

[0089] S42: Acquire one image from each of the two cameras, determine the coordinates of the transition point of the first light source projection in the two images, and obtain the edge point of the topmost cropped piece;

[0090] S43: Calculate the distance between each of the movable grippers and the target point, obtain the change in the distance between the two movable grippers, and adjust the distance between the movable grippers on both sides according to the change;

[0091] S44: Calculate and obtain the moving distance of the feeding gripper 22.

[0092] In step S41 above, the steps of calibrating the camera module and obtaining the target point coordinates at the alignment height include:

[0093] S411: Raise the loading tray until the top layer of cut pieces contacts the fixed gripper, then lower the loading tray by a height H to obtain the alignment height;

[0094] S412: Calculate the distance that the movable gripper should move based on the target point and the transition point of the first light source projection in the camera when the movable gripper is aligned with the edge of the cut piece.

[0095] In the example above, the target point coordinates are pre-defined, defined as the target position that the discontinuity of the cut piece edge should reach. The alignment process involves moving the gripper to make the discontinuity coincide with the target point. Based on the target point and the detected discontinuity, combined with the "millimeters / pixel" scaling factor, the distance the gripper should move can be calculated.

[0096] In the example above, the pixel difference of the camera is calculated by subtracting the detected discontinuity of the cut edge from the target point. The ratio S (pixel / mm) of the pixel difference of the camera to the actual distance is set, and the pixel coordinates of the first projection ray breakpoint in the camera are set when the moving gripper is aligned with the cut edge (ptl(x_ptl, y_ptl) for the left camera and ptr(x_ptr, y_ptr) for the right camera).

[0097] Detect the top edge of the cropped image: acquire one image from the left camera and one from the right camera. In the left camera image, find the first break point bpl (break point left) from right to left, with coordinates (x_bpl, y_bpl). In the right camera image, find the first break point bpr (break point right) from left to right, with coordinates (x_bpr, y_bpr).

[0098] Adjust the distance between the left and right grippers: Calculate the distance between the left gripper and the target point d_l = S*(x_bpl - x_ptl), and the distance between the right gripper and the target point d_r = S*(x_bpr - x_ptr). The change in the distance between the left and right grippers is then d_i = d_l - d_r, where a positive sign for d_i indicates an increase in distance, and a negative sign indicates a decrease in distance. Adjust the distance between the left and right movable grippers based on this calculation.

[0099] Moving feeding and gripping mechanism: Re-detect the edge point of the top layer of cut piece, i.e., acquire one image from the left camera and one from the right camera. In the left camera image, find the first break point bpl (break point left) from right to left, with coordinates (x_bpl, y_bpl). In the right camera image, find the first break point bpr (break point right) from left to right, with coordinates (x_bpr, y_bpr). Then calculate the distance d_t of the feeding and gripping mechanism d_t = S*[(x_ptl - x_bpl) + (x_ptr - x_bpr)] / 2, where a positive sign of d_t indicates movement to the right, and a negative sign indicates movement to the left. Move the feeding and gripping mechanism according to the calculation.

[0100] It should be understood that the directions or positional relationships indicated by "left" and "right" mentioned above are based on the attached... Figure 2 Or attached Figure 3 The orientations or positional relationships shown are for the purpose of facilitating and simplifying the description of the present invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the present invention.

[0101] In step S411 above, in order to determine whether the feeding tray 12 is in contact with the top layer of cut pieces, a photoelectric distance sensor can be installed on the fixed gripper 2231 for detection.

[0102] In summary, this embodiment provides a control method for an automatic positioning and gripping device. It calculates the hem width of the cut piece based on a CAD model of the cut piece; adjusts the spacing between the movable grippers on both sides according to the hem width; adjusts the height of the loading tray to the alignment height; adjusts the position of the movable grippers according to the feedback value of the photoelectric distance sensor to align with the stack of cut pieces; and adjusts the position of the movable grippers according to the feedback value of the camera module to align with the topmost cut piece to be gripped. After aligning the loading tray, the automation and stability of the cut piece stack loading are improved. Combined with the photoelectric distance sensor and camera module, it enables automatic and accurate gripping of the topmost cut piece in a stack of cut pieces, avoiding problems such as misalignment or missing the target.

[0103] The above description is merely a preferred embodiment of the present invention. It should be noted that those skilled in the art can make various improvements and substitutions 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. The basic principles, main features, and advantages of the present invention have been shown and described above. It is obvious to those skilled in the art that the present invention is not limited to the details of the above preferred embodiments. The embodiments should be considered exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the foregoing description. Therefore, it is intended that all changes falling within the meaning and scope of the equivalents of the claims be included within the present invention.

[0104] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in the embodiments can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A control method of an automatic positioning gripping device, characterized by, The automatic positioning and grabbing device comprises: a lifting unit comprising a lifting table and a feeding tray mounted on the lifting table and movable in a third direction, the feeding tray being used for stacking the cutting pieces; and a grabbing unit comprising a stacking table and a feeding grabbing mechanism, the feeding grabbing mechanism comprising a lower support plate arranged on the stacking table and movable in a first direction and an upper support plate arranged on the lower support plate and movable in a second direction, the upper support plate being provided with a gripper assembly, the gripper assembly being provided with a photoelectric distance sensor for detecting and positioning the position of the cutting piece stack in the third direction and a camera module for positioning the edge position of the uppermost cutting piece of the cutting piece stack; wherein the gripper assembly comprises a fixed gripper fixed to the upper support plate and movable grippers symmetrically arranged on both sides of the fixed gripper, the movable grippers being movable in the second direction, and the photoelectric distance sensor and the camera module are arranged on the movable grippers; The control method comprises the following steps: calculating the lower hem width of the cutting piece according to the cutting piece CAD model; adjusting the distance between the movable grippers on both sides according to the lower hem width of the cutting piece; setting the alignment height of the feeding tray; adjusting the height of the feeding tray to the alignment height, adjusting the position of the movable grippers according to the feedback value of the photoelectric distance sensor, and aligning the cutting piece stack; adjusting the position of the movable grippers according to the feedback value of the camera module, and aligning the uppermost cutting piece to be grabbed; grabbing the cutting piece and completing the feeding; wherein the step of adjusting the height of the feeding tray to the alignment height, adjusting the position of the movable grippers according to the feedback value of the photoelectric distance sensor, and aligning the cutting piece stack comprises: setting the distance from the photoelectric distance sensor to the feeding tray when the feeding tray is at the lowest height as a threshold value; obtaining the feedback values of the photoelectric distance sensors corresponding to the movable grippers on both sides; comparing the feedback values of the photoelectric distance sensors on both sides with the threshold value; the step of comparing the feedback values of the photoelectric distance sensors on both sides with the threshold value comprises: if the feedback value of one of the photoelectric distance sensors is less than or equal to the threshold value and the feedback value of the other photoelectric distance sensor is greater than the threshold value, then the grabbing unit moves a distance D in the second direction towards the side with the feedback value less than or equal to the threshold value, and the feedback values of the photoelectric distance sensors corresponding to the movable grippers on both sides are repeatedly obtained; if the feedback values of the photoelectric distance sensors on both sides are greater than the threshold value, then the alignment is successful and the next stage is entered; if the feedback values of the photoelectric distance sensors on both sides are less than or equal to the threshold value, then the alignment fails, the system stops and an alarm is given.

2. The control method of an automatic positioning and gripping device according to claim 1, characterized in that, The camera module comprises: a light source emitting unit for emitting a light source projection to the edge position of the uppermost cutting piece of the cutting piece stack; and a camera for detecting the transition point of the light source projection of the light source emitting unit at the edge of the uppermost cutting piece.

3. The control method of an automatic positioning and gripping device according to claim 2, characterized in that, The projection path of the light source emitting unit is in a non-vertical state with the feeding tray, and the optical axis of the camera is perpendicular to the feeding tray.

4. The control method of an automatic positioning and gripping device according to claim 1, characterized in that, The light exit direction of the photoelectric distance sensor is perpendicular to the feeding tray.

5. The control method of an automatic positioning and gripping device according to claim 1, characterized in that, The step of adjusting the position of the movable gripper according to the feedback value of the camera module and aligning the uppermost layer of the cutting piece to be grabbed includes: Setting the alignment height of the feeding tray, calibrating the camera module, and obtaining the target point coordinates at the alignment height; Obtaining two images of the two sides of the camera, determining the coordinates of the transition point of the first light source projection in the two images, and obtaining the edge point of the uppermost layer of the cutting piece; Calculating the distance between each side of the movable gripper and the target point, obtaining the change amount of the distance between the two movable grippers, and adjusting the distance between the two movable grippers according to the change amount; Calculating and obtaining the moving distance of the feeding and grabbing mechanism.

6. The control method of an automatic positioning and gripping device according to claim 5, characterized in that, The step of setting the alignment height of the feeding tray, calibrating the camera module, and obtaining the target point coordinates at the alignment height includes: Lifting the feeding tray until the uppermost layer of the cutting piece contacts the fixed gripper, and then lowering the feeding tray by a height H to obtain the alignment height; According to the target point and the transition point of the first light source projection in the camera when the movable gripper aligns the edge of the cutting piece, the distance that the movable gripper should move is calculated.

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