A control method for a stacker

Abstract

The application provides a control method for a stacker to unload, which comprises the following steps: selecting a height control model corresponding to the material according to the specification of the material; aligning a platform with the loading platform carrying the material; obtaining an initial height h0 of the loading platform according to the height control model, and a relationship Ex between the material pushing distance and the deformation variable of the loading platform; lifting the loading platform to a position with a distance h0 from the platform; pushing the material on the loading platform to the platform by a pushing arm; judging whether to perform height adjustment according to the specification of the material, and if yes, adjusting the height of the pushing arm and the platform according to the relationship Ex according to the progress of the pushing operation of the pushing arm until the loading platform is leveled with the platform; stopping the movement of the loading platform and keeping the pushing arm to push the material after the loading platform is leveled with the platform; and pushing the material completely away from the loading platform by the pushing arm. The control method for the stacker to unload avoids the situation that the top corner of the material is abraded due to excessive stress in the existing unloading process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electrical automation control, in particular to a control method for unloading of a stacker. BACKGROUND

[0002] The stacker type intelligent vertical warehouse is a commonly used equipment in industry. Since the stacker directly pushes the material to the position (the loading platform is level with the position) in the position, on the one hand, the front end of the material is not accurately aligned with the position, which causes the front end of the material to be damaged in the pushing process, and on the other hand, the whole bottom of the material is pushed for a long distance, which causes abrasion. Therefore, the existing unloading process of the stacker is (see the attached drawings of the specification Figure 1 ), the stacker carries the material to the position, then the stacker rises to a position where the distance between the loading platform and the position is 10-150 mm (if the loading platform is level with the position, the bottom of the material will directly touch and scratch the feeding end of the position when the material is pushed), the material on the loading platform is pushed to the position by the material pushing device on the stacker. Since the material is heavy, the position of the center of gravity of the material relative to the loading platform changes during the pushing process of the material, and there is no supporting point at the outer end of the loading platform, which causes the material to move to the outer end of the loading platform, and the outer end of the material and the loading platform are inclined downward at the same time. In addition, after the material contacts the platform of the position, the position where the material contacts the position (the front corner of the material) acts as a fulcrum, and the front corner of the material is pushed forward during the pushing process of the material, which causes the top corner of the material to be obviously abraded, affecting the appearance of the material. In addition, after the center of gravity of the material is transferred to the position, the loading platform is restored upward, the position where the material contacts the position acts as a fulcrum, and the rear end of the material is turned upward, which further causes the top corner of the material to be pressed. SUMMARY

[0003] The present application aims to overcome the shortcomings of the prior art and provide a control method for unloading of a stacker, which can automatically lower the stacker as the material advances to the position during unloading, avoiding the situation that the top corner of the material is abraded during the existing unloading process.

[0004] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0005] A control method for unloading of a stacker, a material placing system comprising a stacker and a position, the stacker being provided with a lifting mechanism, a loading platform and a material pushing mechanism, the lifting mechanism being used to drive the loading platform to rise and fall, the material pushing mechanism being located above the loading platform and rising and falling with the loading platform, the material pushing mechanism being provided with a material pushing arm which can move back and forth along the front and rear ends of the loading platform; the position being provided with a platform for placing the material;

[0006] The mark of the material is An, and the materials of different specifications are marked as A1, A2, A3…An in turn, wherein n is an integer greater than 0.

[0007] When the different specifications of the material An are pushed out of the loading platform, the pushing distance of the pushing mechanism and the variable change of the loading platform deformation are established to correspond to the material pushing distance-loading platform height control model of the material An;

[0008] Based on the height control model, the maximum value B(max) of the loading platform deformation corresponding to the material is confirmed;

[0009] The control method comprises:

[0010] According to the specifications of the material, the height control model corresponding to the material is selected;

[0011] The loading platform carrying the material is aligned with the platform;

[0012] The loading platform obtains the initial height h0 according to the height control model, and the relationship Ex between the material pushing distance and the loading platform deformation, and the loading platform is raised to the position of h0 from the platform;

[0013] The pushing arm pushes the material on the loading platform to the platform direction;

[0014] The loading platform judges whether to execute the height adjustment according to the specifications of the material, if executed, adjusts the height of the loading platform and the platform according to the relationship Ex according to the progress of the pushing operation of the pushing arm, until the loading platform is leveled with the platform;

[0015] After the loading platform is leveled with the platform, the loading platform stops moving, and the pushing arm keeps pushing the material;

[0016] The pushing arm completely pushes the material away from the loading platform.

[0017] Compared with the prior art, the control method of the stacker discharging has the following beneficial effects:

[0018] (1) In the present application, the loading platform judges whether to execute the height adjustment according to the specifications of the material, if executed, adjusts the height of the loading platform and the platform according to the relationship Ex according to the progress of the pushing operation of the pushing arm, so that the stacker can automatically descend when discharging the material along with the progress of the material pushing into the position, avoiding the situation that the material top corner is stressed too large in the existing unloading process, resulting in obvious wear of the material appearance, so that this situation can be effectively avoided, avoiding the wear of the outer corner of the material, and optimizing the action of the stacker when unloading the material in the vertical warehouse position.

[0019] (2) If the loading platform does not cooperate with the pushing arm operation and is lowered in height, the center of gravity of the material box slowly shifts to the warehouse position during the pushing process, the weight distributed on the loading platform becomes smaller, and the end of the loading platform slowly rebounds upward, causing the tail of the material to be tilted upward, increasing the inclination angle of the front end of the material, increasing the stress, and increasing the friction during movement. In order to solve the problem of material outer corner wear, when the stacker pushes the material to the interface warehouse position, the stacker moves the loading platform to the initial height h0, the loading platform is higher than the warehouse position, and during the pushing process, the center of gravity of the material is determined according to the pushing distance of the pushing arm, and the height of the loading platform is slowly lowered until the warehouse plane supports most of the weight of the material and the loading platform is level with the warehouse plane, and then the pushing arm pushes the material out completely.

[0020] (3) The pushing distance, pushing distance and loading platform height control relationship EX of different materials are different, so different specifications of materials need to be marked in turn, and the corresponding height control model is established.

[0021] Preferably, when collecting data to establish the height control model, the height Dn of the loading platform from the platform plane is collected, where the height Dn is in mm, and the height Dn is taken at intervals in the interval [1, 500], and after placing several materials on the loading platform at several heights Dn, the pushing distance of the pushing mechanism and the change data of the loading platform deformation variable when the material is pushed out of the loading platform are obtained.

[0022] By testing the pushing of the corresponding material at different heights for several times, and the test height Dn is taken at intervals, the relationship Ex can be accurately obtained subsequently, and in addition, in order to avoid the situation that the material falls in the air, the height Dn is taken in the interval [1, 500].

[0023] Preferably, if the loading platform deformation variable of the height control model corresponding to the material An is not greater than 50mm, it is judged that the material An can be directly pushed to the platform with the height D1 of the loading platform from the platform plane.

[0024] At this time, the relationship Ex between the pushing distance of the material and the loading platform deformation variable is not executed, and the initial height h0 is equal to the height D1.

[0025] Preferably, the height D1 is in mm, and D1 [0, 100].

[0026] Preferably, the specifications of the material include the size, weight and hardness of the packaging material of the material.

[0027] Preferably, after obtaining the specification parameters of the material, if it is judged that the hardness of the outer packaging of the material An is greater than the strength value P, it is judged that the material An can be directly pushed to the platform with the height D2 of the loading platform from the platform plane.

[0028] The relationship Ex between the pushing distance of the pushing arm and the deformation of the loading platform is not executed at this time, and the initial height h0 is equal to the height D2.

[0029] Preferably, the height D2 is in mm, and D2∈[5, 100].

[0030] When the material is relatively light, the deformation of the loading platform is relatively small, and the material packaging is strong and not easy to deform, the loading platform can be directly at a specific height relative to the platform, and the relationship Ex is not executed, and the material is directly pushed to improve the carrying efficiency.

[0031] Preferably, the stacker controls the height of the loading platform by reading the pushing distance data of the pushing arm.

[0032] When the center of gravity of the material changes during the pushing of the material, the height of the loading platform is controlled by reading the pushing distance, so as to realize the effective feedback of the change of the pushing distance-the change of the center of gravity of the material-the change of the height of the loading platform.

[0033] Preferably, the initial height h0=M+B(max)-k*G, wherein M is the basic height, M∈[5, 100], G is the correction height, G∈[0, 200], and k is the correction coefficient and greater than 0.

[0034] The maximum deformation B(max) is the critical deformation when the center of gravity of the material is transferred to the outside of the loading platform, so the maximum value of the initial height h0 is M+B(max) (G=0). When the loading platform has the maximum deformation, it means that the material is in the maximum inclination. In order to avoid the material contacting the platform at the maximum inclination, the height of the loading platform needs to be corrected, so the initial height h0=M+B(max)-k*G. The initial height h0 is the height distance maintained by the loading platform when it is docked with the position and the platform plane. For heavy materials, if the initial height h0 is greater than B(max), the front end of the material will be stressed more as the inclination increases after the center of gravity of the material changes, so the initial height h0 needs to be limited to ensure that the center of gravity of the material changes at the same time as the deformation of the loading platform decreases to a specified height before it approaches the maximum value B(max), so as to avoid the inclination of the front and rear ends of the material being too large.

[0035] Preferably, the formula of the descending height h of the loading platform output by the height control model is h=h0*e -KX , wherein X is the pushing distance of the pushing arm, K is the attenuation rate constant, and K is a positive number, and e represents the exponential function expression. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 is a schematic diagram of the execution of the stacker pushing the material to the position in the prior art;

[0037] Figure 2is a first execution case schematic diagram of the stacker pushing the material to the bin position according to the present application;

[0038] Figure 3 is a second execution case schematic diagram of the stacker pushing the material to the bin position according to the present application;

[0039] Figure 4 is a second execution case schematic diagram of the stacker pushing the material to the bin position according to the present application;

[0040] Figure 5 is a curve diagram of the relationship Ex. DETAILED DESCRIPTION

[0041] Embodiments of the present application will be described below with reference to the accompanying drawings:

[0042] Referring to Figures 2 to 4 A control method for a stacker discharge according to the present embodiment is applied to a material placing system, which comprises a stacker and a bin position. The stacker is provided with a lifting mechanism, a loading platform, and a material pushing mechanism. The lifting mechanism is used to drive the loading platform to ascend and descend. The material pushing mechanism is located above the loading platform and ascends and descends with the loading platform. The material pushing mechanism is provided with a material pushing arm that can move back and forth along the front and rear ends of the loading platform. The bin position is provided with a platform for placing materials.

[0043] The materials are marked as An, and different specifications of the materials are marked as A1, A2, A3, …, An in sequence, where n is an integer greater than 0.

[0044] The pushing distance of the material pushing mechanism and the change in the deformation variable of the loading platform when different specifications of the materials An are pushed out of the loading platform are collected, and a height control model of the material pushing distance-loading platform descending height corresponding to the material An is established.

[0045] Based on the height control model, the maximum value B(max) of the deformation variable of the loading platform corresponding to the material is confirmed.

[0046] The control method comprises the following steps.

[0047] According to the specification of the material, the height control model corresponding to the material is selected.

[0048] The loading platform carrying the material is aligned with the platform;

[0049] The loading platform obtains an initial height h0 according to the height control model, and a relationship Ex between the material pushing distance and the deformation variable of the loading platform. The loading platform ascends to a position at a distance h0 from the plane on which the platform is located.

[0050] The material pushing arm pushes the material on the loading platform in the direction of the platform.

[0051] The loading platform determines whether to perform height adjustment according to the specifications of the materials, and if so, adjusts the height of the pushing arm relative to the platform according to the relationship Ex until the loading platform is level with the platform.

[0052] After the loading platform is level with the platform, the loading platform stops moving, and the pushing arm keeps pushing the materials.

[0053] The pushing arm completely pushes the materials away from the loading platform.

[0054] Preferably, when collecting data to establish the height control model, the height Dn of the loading platform relative to the platform is collected, where the unit of the height Dn is mm, the height Dn is taken at intervals in the interval [1, 500], and the pushing distance of the pushing mechanism and the change in the deformation of the loading platform when the materials are pushed out of the loading platform are obtained.

[0055] By performing multiple pushing tests at different heights for the corresponding materials and taking the test heights Dn at intervals, the relationship Ex can be accurately obtained subsequently, and in addition, in order to avoid the materials falling from the air, the height Dn is taken in the interval [1, 500].

[0056] The above steps obtain the mathematical relationship between the height of the loading platform, the pushing distance, and the deformation of the loading platform.

[0057] The data processing and intelligent simulation of the height control model (mathematical model) belong to the application of the prior art, and do not belong to the main invention point of the present application.

[0058] Preferably, referring to Figure 4 If the deformation of the loading platform corresponding to the height control model of the material An is not greater than 50 mm, it is determined that the material An can be directly pushed to the platform at the height D1 of the loading platform relative to the platform.

[0059] At this time, the relationship Ex between the pushing distance of the material and the deformation of the loading platform is not executed, and the initial height h0 is equal to the height D1.

[0060] Preferably, the height D1 is in mm, and D1 ∈ [0, 100].

[0061] Preferably, the specifications of the materials include the size, weight, and hardness of the packaging materials.

[0062] Preferably, referring to Figure 5 After obtaining the specification parameters of the materials, if it is determined that the hardness of the outer packaging of the material An is greater than the strength value P, it is determined that the material An can be directly pushed to the platform at the height D2 of the loading platform relative to the platform.

[0063] The relationship Ex between the pushing distance of the pushing arm and the deformation of the loading platform is not executed at this time, and the initial height h0 is equal to the height D2.

[0064] Preferably, the height D2 is in mm, and D2∈[5, 100].

[0065] When the material is relatively light, the deformation of the loading platform is relatively small, and the material packaging is strong and not easy to deform, the loading platform can be directly placed at a specific height relative to the platform, and the relationship Ex is not executed, and the material is directly pushed to improve the carrying efficiency.

[0066] Preferably, the stacker controls the height of the loading platform by reading the pushing distance data of the pushing arm.

[0067] When the center of gravity of the material changes during the pushing of the material, the height of the loading platform is controlled by reading the pushing distance, so as to realize the effective feedback of the change of the pushing distance-the change of the center of gravity of the material-the change of the height of the loading platform.

[0068] Preferably, the initial height h0=M+B(max)-k*G, wherein M is the basic height, M∈[5, 100], G is the correction height, G∈[0, 200], and k is the correction coefficient and greater than 0.

[0069] The maximum deformation B(max) is the critical deformation when the center of gravity of the material is transferred to the outside of the loading platform, so the maximum value of the initial height h0 is M+B(max) (G=0). When the loading platform has the maximum deformation, it means that the material is in the maximum inclination. In order to avoid the material contacting the platform at the maximum inclination, the height of the loading platform needs to be corrected, so the initial height h0=M+B(max)-k*G. The initial height h0 is the height distance maintained by the loading platform when it is docked with the position and the platform. For heavy materials, if the initial height h0 is greater than B(max), the inclination of the front end of the material will increase and the stress will increase after the center of gravity of the material changes, so the initial height h0 needs to be limited to ensure that the center of gravity of the material changes and the deformation of the loading platform decreases to a specified height before it approaches the maximum value B(max), so as to avoid the inclination of the front and rear ends of the material being too large.

[0070] Preferably, the formula of the descending height h of the loading platform output by the height control model is h=h0*e -KX , wherein X is the pushing distance of the pushing arm, K is the attenuation rate constant, and K is a positive number, and e represents the exponential function expression.

[0071] Description of the drawings in the specification:

[0072] Figures 1 to 4 In the figure, the left side is a position diagram, and the right side is a stacker diagram. The rectangular pattern (with cross marks) placed on the stacker is the material.

[0073] Figure 1 In the specific embodiment, the height of the stacker from the bottom surface of the warehouse is N;

[0074] Figures 2 to 4 In the specific embodiment, the basic height M is set as a reference line.

[0075] Figure 2 In the specific embodiment, the initial height h0 is greater than the basic height M, but in actual application, the initial height h0 can be equal to or less than the basic height M.

[0076] Figure 2 In the specific embodiment, h0, h1, h2 and h3 represent the height changes of the stacker from the bottom surface of the warehouse at different times, and h0, h1, h2 and h3 decrease in turn.

[0077] Figure 3 、 Figure 4 In the specific embodiment, D1 and D2 are less than the basic height M, but in actual production, D2 can be equal to or greater than the basic height M.

[0078] Figure 5 In the specific embodiment, point h0 represents the initial height of the stacker, the point at which the material starts to enter the warehouse, point hn represents the height of the warehouse, the final pushing distance of the pushing arm, and the point at which the material separates from the stacker.

[0079] Figure 5 In the specific embodiment, the curvature of the curve from h0 to hm is greater than the curvature of the curve from hm to hn, that is, the descending speed of the stacker in the height interval from h0 to hm is faster than the descending speed of the stacker in the height interval from hm to hn.

[0080] Compared with the prior art, the control method for the stacker to unload has the following beneficial effects:

[0081] (1) In the present application, the height adjustment is performed according to the size of the material, and if the height adjustment is performed, the height of the pushing arm from the platform is adjusted according to the relationship Ex according to the progress of the pushing operation, so that the stacker can automatically descend with the progress of the material into the warehouse during the unloading process, thereby avoiding the situation that the top corner of the material is subjected to excessive stress, which causes obvious wear of the material, thereby effectively avoiding the occurrence of this situation, avoiding the wear of the outer corner of the material, and optimizing the action of the stacker during the unloading process in the warehouse.

[0082] (2) If the loading platform does not cooperate with the pushing arm operation and is lowered in height, the center of gravity of the material box is slowly transferred to the bin position during the pushing process, the weight distributed on the loading platform becomes smaller, the end of the loading platform slowly rebounds upwards, the tail of the material is lifted up, the inclination angle of the front end of the material is increased, the stress is increased, and the friction during movement is increased; in order to solve the problem of material outer corner wear, when the stacker pushes the material to the docking bin, the stacker moves the loading platform to the initial height h0, the loading platform is higher than the bin surface, and during the pushing process, the change of the center of gravity of the material is judged according to the pushing distance of the pushing arm, and the height of the loading platform is slowly lowered until the bin plane supports most of the weight of the material and the loading platform is level with the bin surface, and then the pushing arm pushes the material out completely;

[0083] (3) The pushing distance of different materials, the pushing distance and the height control relationship EX of the loading platform are different, so it is necessary to mark different specifications of materials in turn, and establish the corresponding height control model.

[0084] According to the disclosure and teaching of the above description, those skilled in the art of the present application can also make changes and modifications to the above embodiments. Therefore, the present application is not limited to the specific embodiments disclosed and described above, and some modifications and changes of the present application should fall within the protection scope of the claims of the present application. In addition, although some specific terms are used in the specification, these terms are only for convenience of description and do not constitute any limitation on the present application.

Claims

1. A method for controlling the unloading of materials by a stacker crane, characterized in that, The material placement system includes a stacker crane and storage units. The stacker crane is equipped with a lifting mechanism, a loading platform, and a pushing mechanism. The lifting mechanism is used to drive the loading platform to move up and down. The pushing mechanism is located above the loading platform and moves up and down with the loading platform. The pushing mechanism is equipped with a pushing arm that can move back and forth along the front and rear ends of the loading platform. The storage units are equipped with platforms for placing materials. Let the material be labeled An, and the materials of different specifications be labeled A1, A2, A3...An in sequence, where n is an integer greater than 0; When materials An of different specifications are pushed out of the loading platform, the pushing distance of the pushing mechanism and the changes in the deformation of the loading platform are collected, and a height control model of the material pushing distance of the corresponding material An minus the descent height of the loading platform is established. Based on the height control model, the maximum value of the loading platform shape variable B (max) of the corresponding material is determined. The control method includes: Select the appropriate height control model based on the material's specifications. A loading platform for aligning materials; The loading platform obtains an initial height h0 based on the height control model, as well as the relationship between the material pushing distance and the loading platform deformation Ex. The loading platform rises to a position h0 away from the plane where the platform is located. The pusher arm pushes the material on the loading platform toward the platform; The loading platform determines whether to perform height adjustment based on the specifications of the material. If so, it adjusts its height relative to the platform according to the progress of the pushing operation of the pusher arm, based on the relationship Ex, until the loading platform is level with the platform. Once the loading platform is level with the platform, the loading platform stops moving, and the pusher arm continues to push the material. The pusher arm completely pushes the material away from the loading platform; when collecting data to establish a height control model, data is collected based on the height Dn of the loading platform from the plane where the platform is located. The height Dn is in mm and is taken at intervals in the range [1, 500]. Data on the pushing distance of the pusher mechanism and the change in the deformation of the loading platform when a certain amount of material is placed on a loading platform of a certain height Dn are obtained.

2. The control method according to claim 1, characterized in that, If the deformation of the loading platform of the height control model corresponding to material An is not greater than 50mm, then it is determined that material An can be directly pushed to the platform at the height D1 of the loading platform from the plane where the platform is located. Assume that the relationship between the material pushing distance and the loading platform shape is not executed at this time, and the initial height h0 is equal to the height D1.

3. The control method according to claim 2, characterized in that, The height D1 is in mm and D1∈[0,100].

4. The control method according to claim 1, characterized in that, Material specifications include the material's dimensions, weight, and the rigidity of the packaging.

5. The control method according to claim 4, characterized in that, After obtaining the specifications of the material, if it is determined that the hardness of the outer packaging of material An is greater than the strength value P, then it is determined that material An can be directly pushed to the platform at the height D2 of the loading platform from the plane of the platform. Assume that the relationship between the material pushing distance and the loading platform shape is not executed at this time, and the initial height h0 is equal to the height D2.

6. The control method according to claim 5, characterized in that, The height D2 is in mm and D2∈[5,100].

7. The control method according to claim 1, characterized in that, The stacker crane controls the height of the loading platform by reading the pushing distance data of the pusher arm.

8. The control method according to claim 1, characterized in that, The initial height h0 = M + B(max) - k*G, where M is the base height, M∈[5,100], G is the correction height, G∈[0,200], and k is the correction coefficient and is greater than 0.

9. The control method according to claim 7, characterized in that, The formula for the lowering height h of the loading platform output by the height control model is h = h0 * e -KX , where X is the pushing distance of the pusher arm, K is the decay rate constant and K is a positive number, and e represents the exponential function expression.

Images