Manipulator stacking flying grabbing method

Abstract

The invention relates to a manipulator stacking flying grabbing method, which adopts a dynamic grabbing mode, and accurately controls the movement of a mechanical gripper, so that the mechanical gripper can quickly and stably grab glass plates flowing on a production line in the process of synchronously running along with a roller way. By means of the flying grabbing mode, the low-efficiency link that in a traditional static grabbing mode, a mechanical gripper needs to wait for a glass plate to stop is thoroughly abandoned, continuous operation in the production process is achieved, and the production takt time of a single product is remarkably shortened. Therefore, the productivity of the production line is directly and greatly improved, the product output in unit time is remarkably increased, and the production efficiency is greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of photovoltaic glass manufacturing, in particular to a manipulator stacking flying grabbing method. Background Art

[0002] In the existing technology, with the continuous development of industrial automation technology, more and more industrial robots are used in various links of production and manufacturing to improve production efficiency, reduce labor costs and improve product quality. In the glass production industry, especially in the production process of large-size and high-yield glass, the handling and stacking of glass sheets is a key link.

[0003] In order to solve the problems of manual handling and stacking, some automated handling and stacking technologies have been introduced into glass production lines. The existing technical solutions mainly use industrial robots for static grasping and stacking or use dedicated roller following encoders. Among them, the method of using industrial robots for static grasping and stacking usually uses industrial robots equipped with suction cup grippers to grasp the glass plates when they are stationary, and then transport them to the stacking rack for stacking. The disadvantage of this method is that it is necessary to wait for the glass plates to stop on the roller before grasping, which reduces the overall efficiency of the production line and cannot meet the needs of high-yield glass production lines; and using a dedicated roller following encoder to obtain the speed information of the roller and synchronize it to the mechanical gripper control system. Although this method can achieve a certain degree of dynamic grasping, it requires additional, expensive dedicated encoders, which increases the cost and complexity of the system.

[0004] In summary, the existing glass plate handling and stacking technology solutions have the following problems: low gripping efficiency, high system cost, poor adaptability to glass plates and stacking racks, low degree of automation, etc. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a flying grabbing method for stacking by a robot, which enables a robot grabber to grab while following the movement of a roller, without waiting for the glass sheet to stop.

[0006] In order to achieve the above object, the manipulator stacking flying grasping method designed by the present invention comprises the following steps:

[0007] S10. Obtaining movement information of the glass sheet conveyed by the roller on the production line, the movement information including the movement speed, size information and position information of the glass sheet; wherein the movement speed of the glass sheet is obtained by acquiring the speed of the roller in real time through the industrial bus; the size information of the glass sheet is obtained by inputting or measuring in advance; the position information of the glass sheet is obtained by detecting the front position of the glass sheet by a photoelectric sensor arranged on the roller;

[0008] S20. When the photoelectric sensor detects the front edge of the glass plate, the mechanical gripper is controlled to move from the initial position to the preparatory gripping point, and the gripping posture of the mechanical gripper is adjusted. The preparatory gripping point is located above the movement path of the glass plate, and a time margin is reserved for the mechanical gripper to reach the gripping position;

[0009] S30. After the mechanical gripper reaches the preparatory grasping point, the movement speed and position of the mechanical gripper are adjusted in real time through the PID algorithm according to the movement speed of the glass plate obtained, so that the mechanical gripper moves synchronously with the glass plate;

[0010] S40. According to the size information of the glass plate and the position of the glass plate relative to the center of the adsorption plane, the gripping position of the glass plate is determined, and when the glass plate reaches the gripping position, the mechanical gripper is controlled to descend and adsorb the glass plate; the mechanical gripper is a suction cup gripper, and the suction cup gripper has multiple grouped air paths, and according to the size information of the glass plate, the opening and closing of each air path is controlled to adapt to glass plates of different plate shapes;

[0011] S50. The mechanical gripper grabs the glass sheet and lifts the glass sheet to the side of the target stacking rack, and detects the depth and position information of the stacking surface of the stacking rack through the plane sensor provided on the mechanical gripper, adjusts the position and posture of the mechanical gripper, and places the glass sheet on the stacking rack;

[0012] S60. After releasing the glass sheet, the mechanical gripper returns to the initial position or waiting position to prepare for the next gripping and stacking cycle.

[0013] Preferably, in step S30, the specific steps of the PID algorithm include:

[0014] Set the output signal to be the control signal U[t] of the mechanical gripper movement speed;

[0015] Set the sampling time to t, and the sampling interval is less than or equal to 10ms;

[0016] Set the proportional coefficient to K, the integral coefficient to I, the differential coefficient to D, the glass plate movement speed to Vg, and the actual movement speed of the mechanical gripper to Vr;

[0017] The error is set to e[t], where e[t] = Vg(t) - Vr(t);

[0018] Calculate the control signal U[t] using the formula: U[t] = K*e[t] + I*Σe(j) + D*(e[t] - e[t-1]), where Σe(j) is the accumulated value of the error and j ranges from 0 to t;

[0019] According to the control signal U[t], the movement speed of the mechanical gripper is controlled so that the speed of the mechanical gripper reaches the same set value as the speed of the glass plate.

[0020] Preferably, in step S40, the control method of the multi-channel grouping gas path includes:

[0021] Divide the suction cup into multiple independently controlled air circuit groups;

[0022] Select the required suction cup set according to the size information of the glass plate;

[0023] The air circuit valve of the selected suction cup group is controlled to be opened, and the air circuit valve of the unselected suction cup group is controlled to be closed.

[0024] Preferably, in step S50, after the mechanical gripper descends to absorb and grasp the glass plate, the edge position of the glass plate is detected by a plurality of edge detection sensors arranged on the mechanical gripper to obtain the position of the glass plate relative to the center of the absorption plane of the mechanical gripper.

[0025] Preferably, the method for determining the preliminary grasping point of the mechanical gripper includes:

[0026] The time required for the glass plate to reach the grasping position is calculated according to the moving speed of the glass plate and the distance of the glass plate from the photoelectric sensor to the grasping position;

[0027] Determine the start time of the mechanical gripper according to the movement time of the mechanical gripper from the initial position to the preparatory grasping point;

[0028] Reserve a time margin of no less than 10% to ensure that the mechanical gripper can reach the preparatory grasping point in time.

[0029] Preferably, in step S50, before placing the glass sheet on the stacking rack, the process further includes:

[0030] Determine the stacking layer number of the current glass plate according to the stacked number;

[0031] Adjust the placement height according to the number of stacking layers.

[0032] The manipulator stacking flying grabbing method designed in the present invention adopts a dynamic grabbing mode, and by precisely controlling the movement of the manipulator gripper, it can quickly and stably grab the glass plates flowing on the production line while following the synchronous operation of the roller. This flying grabbing method completely abandons the inefficient link in the traditional static grabbing mode where the manipulator gripper needs to wait for the glass plate to stop, realizes the continuous operation of the production process, and significantly shortens the production cycle time of a single product. As a result, the production line capacity has been directly and significantly improved, the product output per unit time has increased significantly, and the production efficiency has been greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a flow chart of the manipulator stacking flying grasping method provided in the embodiment of the present application.

[0034] Figure 2 It is a schematic diagram of the mechanical gripper structure provided in an embodiment of the present application.

[0035] Figure 3 It is a schematic diagram of the speed adjustment of the mechanical gripper provided in an embodiment of the present application. DETAILED DESCRIPTION

[0036] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0037] The flying grasping method for stacking by a robot described in this embodiment adopts a dynamic grasping mode to realize the grasping and stacking of glass plates by the robot grasper in motion, thereby improving production efficiency, reducing costs, and enhancing adaptability to different glass plates and stacking racks.

[0038] like Figures 1 to 3 As shown, the specific steps include:

[0039] S10. Obtain the movement information of the glass plate conveyed by the roller on the production line, the movement information includes the movement speed of the glass plate, the size information of the glass plate and the position information; wherein, the movement speed of the glass plate is obtained by acquiring the speed of the roller in real time through the industrial bus; the size information of the glass plate is obtained by pre-input or measurement; the position information of the glass plate is obtained by detecting the front position of the glass plate through a photoelectric sensor (such as a beam photoelectric switch) set on the roller. In this way, the speed, size and position information of the glass plate can be fully obtained, providing a data basis for subsequent precise control, and the real-time acquisition of the roller speed through the industrial bus ensures the accuracy and real-time nature of the speed information, which is the prerequisite for achieving precise grasping.

[0040] S20. When the photoelectric sensor detects the front edge of the glass plate, the mechanical gripper is controlled to move from the initial position to the preparatory gripping point and the gripping posture of the mechanical gripper is adjusted. The preparatory gripping point is located above the movement path of the glass plate and a time margin is reserved for the mechanical gripper to reach the gripping position.

[0041] Specifically, when the photoelectric sensor detects the leading edge of the glass plate, the control system immediately triggers the mechanical gripper to move from its standby position (for example, above the side of the roller) to above the glass plate, and adjusts the gripper's posture according to the movement direction of the glass plate so that it is parallel to the movement direction of the glass plate, preparing for subsequent following and grasping actions, saving time.

[0042] In one embodiment, the method for determining the preparatory grasping point of the mechanical gripper includes: calculating the time required for the glass plate to reach the grasping position based on the movement speed of the glass plate and the distance of the glass plate from the photoelectric sensor to the grasping position; determining the start time of the mechanical gripper based on the movement time of the mechanical gripper from the initial position to the preparatory grasping point; and reserving a time margin of no less than 10% to ensure that the mechanical gripper can reach the preparatory grasping point in time.

[0043] Assume that on a glass production line, the movement speed of the glass plate is 1 m / s, the photoelectric sensor is installed 5 meters away from the grasping position, and it takes 2 seconds for the mechanical gripper to move from the initial position to the preparatory grasping point.

[0044] Before the production line starts running, the parameters such as the moving speed of the glass plate (1 m / s), the distance from the photoelectric sensor to the gripping position (5 m), and the moving time of the mechanical gripper from the initial position to the preparatory gripping point (2 s) are pre-entered into the control system of the mechanical gripper. The preparatory gripping point is set to be directly above the moving path of the glass plate and 0.2 m away from the surface of the glass plate:

[0045] When the front edge of the glass plate reaches the position of the photoelectric sensor, the photoelectric sensor sends a trigger signal to the control system. The control system calculates that the time required for the glass plate to reach the grasping position is 5 seconds based on the movement speed of the glass plate (1 m / s) and the distance from the photoelectric sensor to the grasping position (5 m). The control system determines that the start time of the mechanical gripper should be 3 seconds after the photoelectric sensor is triggered based on the movement time of the mechanical gripper from the initial position to the preparatory grasping point (2 seconds). Considering that at least 10% of the time margin, i.e. 0.5 seconds, needs to be reserved, the actual start time of the mechanical gripper should be 2.5 seconds after the photoelectric sensor is triggered; 2.5 seconds after the electric sensor is triggered, the control system controls the mechanical gripper to start moving from the initial position (for example, above the side of the roller), and the target position is the preparatory grasping point. At the same time, the mechanical gripper adjusts the posture of the gripper according to the movement direction of the glass plate (for example, along the positive direction of the X-axis) to make the suction cup plane parallel to the surface of the glass plate and the movement direction of the gripper consistent with the movement direction of the glass plate. After 2 seconds of movement, the mechanical gripper reaches the preparatory grasping point and keeps its posture and speed synchronized with the glass plate. At this time, the glass plate is about to reach the grasping position, thereby ensuring the timeliness and reliability of the grasping and avoiding the grasping failure caused by the lagging action of the mechanical gripper.

[0046] S30. After the mechanical gripper reaches the preparatory grasping point, the movement speed and position of the mechanical gripper are adjusted in real time through the PID algorithm according to the acquired movement speed of the glass plate, so that the mechanical gripper moves synchronously with the glass plate.

[0047] Specifically, the specific steps of the PID algorithm include:

[0048] Set the output signal to be the control signal U[t] of the mechanical gripper movement speed;

[0049] Set the sampling time to t, and the sampling interval is less than or equal to 10ms;

[0050] Set the proportional coefficient to K, the integral coefficient to I, the differential coefficient to D, the glass plate movement speed to Vg, and the actual movement speed of the mechanical gripper to Vr;

[0051] The error is set to e[t], where e[t] = Vg(t) - Vr(t);

[0052] Calculate the control signal U[t] using the formula: U[t] = K*e[t] + I*Σe(j) + D*(e[t] - e[t-1]), where Σe(j) is the accumulated value of the error and j ranges from 0 to t;

[0053] According to the control signal U[t], the movement speed of the mechanical gripper is controlled so that the mechanical gripper speed reaches the same set value as the glass plate speed. In this way, during the operation, the values ​​of PID parameters K, I, and D can be adjusted in real time according to the actual movement state and speed deviation of the mechanical gripper. For example, if the mechanical gripper speed response is slow, the K value can be increased; if the mechanical gripper speed oscillates, the D value can be adjusted appropriately; if the steady-state error is large, the I value can be adjusted appropriately; that is, by comparing the actual speed of the mechanical gripper and the movement speed of the glass plate in real time, and dynamically adjusting the control signal according to the size, accumulation, and change trend of the error, the movement speed of the mechanical gripper can be accurately controlled so that it always keeps synchronization with the glass plate. This dynamic adjustment strategy not only realizes the synchronous movement of the mechanical gripper and the glass plate, but also ensures the stability and reliability of the following process, providing accurate position and speed for subsequent grasping actions.

[0054] S40. Determine the gripping position of the glass plate according to the size information of the glass plate and the position of the glass plate relative to the center of the adsorption plane. When the glass plate reaches the gripping position, control the mechanical gripper to descend and adsorb the glass plate. The mechanical gripper is a suction cup gripper having multiple grouped air paths, and controls the on and off of each air path according to the size information of the glass plate to adapt to glass plates of different shapes.

[0055] When implementing it, Figure 2As shown, the control method of the multi-channel grouped gas path includes: dividing the suction cup into a plurality of independently controlled gas path groups 100; selecting the required suction cup group according to the size information of the glass plate; controlling the gas path valve of the selected suction cup group to be opened, and the gas path valve of the unselected suction cup group to be closed. For example, for a glass plate of a larger size, all gas paths can be opened so that all suction cup groups participate in the adsorption to ensure uniform suction force distribution, thereby avoiding grasping failure or damage to the glass plate due to insufficient suction force or uneven distribution; and for a glass plate of a smaller size, only part of the gas paths can be opened so that part of the suction cup groups participate in the adsorption, thereby avoiding unnecessary compressed air consumption and reducing energy consumption and production costs.

[0056] S50. The mechanical gripper grabs the glass plate and lifts the glass plate to the side of the target stacking rack, and detects the depth and position information of the stacking surface of the stacking rack through the plane sensor set on the mechanical gripper, adjusts the position and posture of the mechanical gripper, and places the glass plate on the stacking rack.

[0057] Specifically, after the mechanical gripper grabs the glass plate, it starts to move the glass plate to the top of the target stacking rack according to the predetermined path. When it reaches the top of the stacking rack, the plane sensor (such as a plane displacement sensor) installed on the mechanical gripper starts to work. During the descent of the mechanical gripper, the control system will pre-set a target pressure depth value. For example, when each layer of glass plates is stacked, the mechanical gripper should press 5mm. At this time, the pressure depth detection process is as follows:

[0058] When the mechanical gripper begins to descend, the plane sensor begins to measure the distance between it and the stacking rack (or the stacked glass plates) below. As the mechanical gripper descends, the sensor will feed back the current pressure depth data to the control system in real time. The control system compares the real-time pressure depth data fed back by the plane sensor with the preset target pressure depth value (5mm): if the current pressure depth is less than the target value, it will continue to descend; if the current pressure depth is equal to the target value, it will stop descending and place the glass plate, and release the suction cup; if the current pressure depth is greater than the target value, it will stop descending and release the suction cup. In this way, the mechanical gripper can accurately control the pressure depth during stacking, ensuring that each stacking can be completed accurately and reliably without scratches.

[0059] In some embodiments, in step S50, Figure 2 As shown, after the mechanical gripper descends to absorb and grasp the glass plate, the edge position of the glass plate is detected by multiple edge detection sensors 200 (such as photoelectric sensors) arranged on the mechanical gripper to obtain the position of the glass plate relative to the center of the absorption plane of the mechanical gripper.

[0060] In specific implementation, the edge detection sensor 200 is installed on the mechanical gripper through the X-axis drive mechanism and the Y-axis drive mechanism, and can accurately detect the position of the edge of the glass plate relative to the mechanical gripper, so that in the subsequent stacking operation, the control system will accurately compensate the motion trajectory of the mechanical gripper according to the calculated position deviation (X-axis offset to the right by 0.05 meters, Y-axis offset downward by 0.05 meters). For example, when the mechanical gripper transports the glass plate to the top of the stacking rack for placement, the control system will control the mechanical gripper to first translate 0.05 meters to the left, then translate 0.05 meters upward, based on the original trajectory, and then perform the placement action. In this way, even if there is a deviation during grasping, through precise compensation, the glass plate can still be accurately placed in the center of the stacking rack, ensuring the accuracy and quality of the stacking, and avoiding problems such as stacking misalignment or tilt caused by accumulated deviations.

[0061] S60. After releasing the glass sheet, the mechanical gripper returns to the initial position or waiting position to prepare for the next gripping and stacking cycle.

[0062] In some embodiments, before placing the glass sheet on the stacking rack in step S50, the steps further include: determining the stacking layer number of the current glass sheet according to the stacked number; determining the stacking layer number of the current glass sheet according to the stacked number; and adjusting the placement height according to the stacking layer number. This step ensures that the mechanical gripper can adjust the height according to the actual height of the current stacking surface when placing the glass sheet, avoiding collision, unstable placement, and other problems caused by placing the glass sheet too high or too low.

[0063] The flying grabbing method for stacking with a manipulator provided in this embodiment adopts a dynamic grabbing mode, and by precisely controlling the movement of the manipulator gripper, it can quickly and stably grab the glass plates flowing on the production line while following the synchronous operation of the roller. This flying grabbing method completely abandons the inefficient link in the traditional static grabbing mode where the manipulator gripper needs to wait for the glass plate to stop, realizes the continuous operation of the production process, and significantly shortens the production cycle time of a single product. As a result, the production line capacity has been directly and significantly improved, the product output per unit time has increased significantly, and the production efficiency has been greatly improved.

[0064] In the description of the present invention, it should be noted that the terms "vertical", "up", "down", "horizontal", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0065] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0066] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A flying grabbing method for stacking with a manipulator, characterized in that: The following steps are involved: S10. Obtaining movement information of the glass sheet conveyed by the roller on the production line, the movement information including the movement speed, size information and position information of the glass sheet; wherein the movement speed of the glass sheet is obtained by acquiring the speed of the roller in real time through the industrial bus; the size information of the glass sheet is obtained by inputting or measuring in advance; the position information of the glass sheet is obtained by detecting the front position of the glass sheet by a photoelectric sensor arranged on the roller; S20. When the photoelectric sensor detects the front edge of the glass plate, the mechanical gripper is controlled to move from the initial position to the preparatory gripping point, and the gripping posture of the mechanical gripper is adjusted. The preparatory gripping point is located above the movement path of the glass plate, and a time margin is reserved for the mechanical gripper to reach the gripping position; S30. After the mechanical gripper reaches the preparatory grasping point, the movement speed and position of the mechanical gripper are adjusted in real time through the PID algorithm according to the movement speed of the glass plate obtained, so that the mechanical gripper moves synchronously with the glass plate; S40. Control the mechanical gripper to descend and absorb the glass plate; the mechanical gripper is a suction cup gripper, which has a multi-channel grouped gas path, and controls the on-off of each gas path according to the size information of the glass plate to adapt to different types of glass plates; S50. The mechanical gripper grabs the glass sheet and lifts the glass sheet to the side of the target stacking rack, and detects the depth and position information of the stacking surface of the stacking rack through the plane sensor provided on the mechanical gripper, adjusts the position and posture of the mechanical gripper, and places the glass sheet on the stacking rack; S60. After releasing the glass sheet, the mechanical gripper returns to the initial position or waiting position to prepare for the next gripping and stacking cycle.

2. The method for flying stacking by a manipulator according to claim 1, characterized in that: In step S30, the specific steps of the PID algorithm include: Set the output signal to be the control signal U[t] of the mechanical gripper movement speed; Set the sampling time to t, and the sampling interval is less than or equal to 10ms; Set the proportional coefficient to K, the integral coefficient to I, the differential coefficient to D, the glass plate movement speed to Vg, and the actual movement speed of the mechanical gripper to Vr; The error is set to e[t], where e[t] = Vg(t) - Vr(t); Calculate the control signal U[t] using the formula: U[t] = K*e[t] + I*Σe(j) + D*(e[t] - e[t-1]), where Σe(j) is the accumulated value of the error and j ranges from 0 to t; According to the control signal U[t], the movement speed of the mechanical gripper is controlled so that the speed of the mechanical gripper reaches the same set value as the speed of the glass plate.

3. The method for flying stacking by a manipulator according to claim 1, characterized in that: In step S40, the control method of the multi-channel grouping gas path includes: Divide the suction cup into multiple independently controlled air circuit groups; Select the required suction cup set according to the size information of the glass plate; The air circuit valve of the selected suction cup group is controlled to be opened, and the air circuit valve of the unselected suction cup group is controlled to be closed.

4. The method for flying stacking by a manipulator according to claim 1, characterized in that: In step S50, after the mechanical gripper descends to absorb and grasp the glass plate, the edge position of the glass plate is detected by a plurality of edge detection sensors arranged on the mechanical gripper to obtain the position of the glass plate relative to the center of the absorption plane of the mechanical gripper.

5. The method for flying stacking by a manipulator according to claim 1, characterized in that: The method for determining the preliminary grasping point of the mechanical gripper includes: The time required for the glass plate to reach the grasping position is calculated according to the moving speed of the glass plate and the distance of the glass plate from the photoelectric sensor to the grasping position; Determine the start time of the mechanical gripper according to the movement time of the mechanical gripper from the initial position to the preparatory grasping point; Reserve a time margin of no less than 10% to ensure that the mechanical gripper can reach the preparatory grasping point in time.

6. The method for flying stacking by a manipulator according to claim 1, characterized in that: In step S50, before placing the glass sheet on the stacking rack, the process further includes: Determine the stacking layer number of the current glass plate according to the stacked number; Adjust the placement height according to the number of stacking layers.

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