AUTOMATED CRANE CONTROLLER TAKING INTO ACCOUNT LOAD- AND POSITION-DEPENDENT MEASUREMENT ERRORS
20180050889 · 2018-02-22
Assignee
Inventors
Cpc classification
F16F15/002
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
B66C13/48
PERFORMING OPERATIONS; TRANSPORTING
F16F7/1011
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
B66C13/066
PERFORMING OPERATIONS; TRANSPORTING
International classification
B66C13/48
PERFORMING OPERATIONS; TRANSPORTING
B66C13/08
PERFORMING OPERATIONS; TRANSPORTING
Abstract
A control method for a handling system includes when a trolley is loaded at a target location by a target loading, matching by a crane controller the target location of the trolley on a crossmember with a target location of a load handling point on the substrate, such that a target load is lowered onto the target location of the load handling point, when the target load is lowered at the target location of the trolley, positioning the trolley at the target location by the crane controller, subsequently lowering the target load onto the load handling point by the crane controller and positioning the load handling point at the target location before the target load is lowered onto the load handling point, when the load handling point is movable on the substrate and the load handling point is controlled by the crane controller.
Claims
1.-15. (canceled)
16. A control method for a handling system which includes a container bridge arranged on a substrate with a trolley that is movable on a crossmember of the container bridge relative to the substrate, and at least one load handling point arranged on the substrate, said method comprising: when the trolley is loaded at a target location by a target loading, matching by a crane controller the target location of the trolley on the crossmember with a target location of a load handling point on the substrate such that a target load is lowered onto the target location of the load handling point, when the target load is lowered at the target location of the trolley; positioning the trolley at the target location by the crane controller; subsequently lowering the target load onto the load handling point by the crane controller; and positioning the load handling point at the target location before the target load is lowered onto the load handling point, when the load handling point is movable on the substrate and the load handling point is controlled by the crane controller.
17. The control method of claim 16, further comprising: informing the crane controller about the target location of the load handling point during matching of the target location of the trolley with the target location of the load handling point; and determining by the crane controller the target location of the trolley in dependence on the target location of the load handling point and the target loading.
18. The control method of claim 16, further comprising: acquiring at a first acquisition time point measured values for the target location of the load handling point by sensors arranged on the container bridge; and when the trolley is located on the crossmember at a first acquisition location at the first acquisition time point and loaded by a first acquisition loading at the first acquisition time point, determining by the crane controller the target location of the load handling point in dependence on the measured values for the target location of the load handling point.
19. The control method of claim 18, further comprising when determining the target location of the load handling point, determining by the crane controller at the first acquisition time point at least one member selected from the group consisting of a time derivative of the first acquisition location, a distance of the target load from the trolley, a time derivative of the distance of the target load from the trolley, and an oscillation state of the target load relative to the trolley.
20. The control method of claim 16, further comprising: moving the load handling point on the substrate in response to an actuation by the crane controller; informing the crane controller about the target location of the trolley during matching of the target location of the trolley with the target location of the load handling point; and determining by the crane controller the target location of the load handling point in dependence on the target location of the trolley and the target loading.
21. The control method of claim 16, further comprising: moving the load handling point on the substrate in response to an actuation by the crane controller; acquiring at a second acquisition time point measured values for an actual location of the load handling point by sensors arranged on the container bridge; when the trolley is located on the crossmember at a second acquisition location at the second acquisition time point and loaded by a second acquisition loading at the second acquisition time point, determining by the crane controller the actual location of the load handling point in dependence on the measured values for the actual location of the load handling point; and determining by the crane controller control commands for positioning the load handling point as a function of a deviation of the actual location determined of the load handling point from the target location of the load handling point.
22. The control method of claim 21, further comprising when determining the actual location of the load handling point, determining by the crane controller at the second acquisition time point at least one member selected from the group consisting of a time derivative of the second acquisition location, a distance of the target load from the trolley, a time derivative of the distance of the target load from the trolley, and an oscillation state of the target load relative to the trolley.
23. The control method of claim 16, further comprising: correcting by the crane controller a target height of the target load in dependence on the target location of the trolley and the target loading; and lowering by the crane controller the target load to the corrected target height.
24. The control method of claim 23, further comprising: acquiring at a third acquisition time point measured values for the target height by sensors arranged on the container bridge; and when the trolley is located on the crossmember at a third acquisition location at the third acquisition time point and loaded by a third acquisition loading at the third acquisition time point, determining by the crane controller the target height in dependence on the measured values for the target height.
25. The control method of claim 24, further comprising when determining the target height, determining by the crane controller at the third acquisition time point at least one member selected from the group consisting of a time derivative of the third acquisition location, a distance of the target load from the trolley, a time derivative of the distance of the target load from the trolley, and an oscillation state of the target load relative to the trolley.
26. The control method of claim 16, further comprising: storing a model of the container bridge in the crane controller, with the model including at least one member selected from the group consisting of a correction table, a rod support model of the container bridge, and a model of the container bridge based on finite elements; and during matching of the target location of the trolley with the target location of the load handling point, implementing by the crane controller the model of the container bridge in dependence on a loading of the trolley and a location of the trolley on the crossmember.
27. A computer program embodied in a non-transitory computer readable medium, said computer program comprising machine code which, when executed by a crane controller, causes the crane controller to carry out a control method as set forth in claim 16.
28. The computer program of claim 27, stored in a memory in a machine-readable form.
29. A crane controller, comprising a computer program embodied in a non-transitory computer readable medium, said computer program comprising machine code which, when executed by the crane controller, causes the crane controller to carry out a control method as set forth in claim 16.
30. A handling system, comprising: a container bridge arranged on a substrate, said container bridge including a crossmember and a trolley movable on the crossmember relative to the substrate; a load handling point arranged on the substrate; and a crane controller comprising a computer program embodied in a non-transitory computer readable medium, said computer program comprising machine code which, when executed by the crane controller, causes the crane controller to carry out a control method as set forth in claim 16.
Description
[0055] The above-described properties, features and advantages of this invention and also the manner in which these are achieved will become clearer and more plainly comprehensible in conjunction with the following description of the exemplary embodiments explained in more detail in conjunction with the drawing. The drawings show in schematic form:
[0056]
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[0060]
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[0065]
[0066] According to
[0067] The container bridge 1 furthermore has a trolley 6. The trolley 6 can be moved on the crossmember 5 relative to the substrate. The direction of movement of the trolley 6 is horizontal and orthogonal to the direction of movement of the support pillars 2.
[0068] The trolley 6 is connected to a spreader 8 by means of a cable system 7. The spreader 8 can be lowered or raised by extending or shortening the cable system 7. Together with the spreader 8, a container 9, which is gripped by the spreader 8, is optionally also lowered or raised. At each time point, a respective current load of the trolley 6 corresponds to the weight of the spreader 8 plus the weight of the container 9 gripped by the spreader 8.
[0069] The following differentiates between the load of the trolley 6 and the loading thereof. The load is the object as such which is moved by the trolley 6, i.e. the spreader 8 with or without the container 9. The loading of the trolley 6 is the weight force exerted by the load on the trolley 6. If, for example, the trolley 6 moves the empty spreader 8 and the weight of the spreader 8 is 5 metric tons, the load of the spreader 8 and the loading is 5 metric tons. The difference between load and loading is also retained in the following in conjunction with compound terms, for example for a target load and a target loading or for an acquisition load and an acquisition loading.
[0070] The handling system has at least one load handling point 10, 11. The load handling point 10, 11 can, for example, be a permanently installed load handling point 10, i.e. a load handling point, which cannot be moved on the substrate 3. A typical example of such a handling point 10 is a storage space for a container 9. Alternatively, the load handling point 10, 11 can be a mobile load handling point 11, i.e. a load handling point, which can be moved on the substrate 3. A typical example of such a load handling point 11 is an AGV (automated guided vehicle).
[0071] The handling system furthermore has a crane controller 12. The crane controller 12 controls the handling system. The crane controller 12 is programmed with a computer program 13. The computer program 13 is in particular stored in a memory 14 of the crane controller 12 in machine-readable form. The computer program 13 comprises a machine code 15, which can be executed by the crane controller 12. The execution of the machine code 15 by the crane controller 12 causes the crane controller 12 to carry out a control method for the handling system, which is explained in more detail below.
[0072] According to
[0073] The Step S1 can be implemented in different ways. For example, when the spreader 8 has previously been raised, it is possible to determine loading of a hoisting gear by means of which the cable system 7 is actuated. In this case, it is possible to determine the loading L from the loading of the hoisting gear. Alternatively, it is, for example, possible for the weight of the spreader 8 to be known to the crane controller 12. When the (empty) spreader 8 is to be lowered, the loading L corresponds to the weight of the spreader 8. When the spreader 8 is to be lowered together with a container 9, the crane controller 12 can be notified, for example by a user or a higher-ranking control system (neither shown in FIG) of the weight of the corresponding containers 9.
[0074] At this time point, i.e. when the spreader 8 is lowered, the trolley 6 is located on the crossmember 5 at a location xK. The location xK is a target location for the trolley 6. It is related to the crossmember 5, to be more precise to the direction of movement of the trolley 6 on the crossmember 5. The spreader 8 should be lowered (with or without containers 9) such that, when the spreader 8 is lowered at the target location xK of the trolley 6, the spreader 8 is lowered onto a location xL of the corresponding load handling point 10, 11. The location xL is a target location of the corresponding load handling point 10, 11. The target location xL of the corresponding load handling point 10, 11 is related to the substrate 3.
[0075] To ensure correct lowering of the spreader 8, the two target locations xK, xL must be matched to one another. The following describes one possible procedure for such matching in conjunction with Steps S2 to S8.
[0076] According to
[0077] In Step S3, the crane controller 12 provisionally determines the corresponding target location xK of the trolley 6. The determination in Step S3 is an ideal determination. It is based on the assumption that the container bridge 1 is an absolutely rigid system. In this case, the target location xL of the load handling point 10, 11 can be adopted directly 1:1 as the target location xK of the trolley 6.
[0078] However, in practice, the container bridge 1 is an elastic system. Depending upon the position of the trolley 6 on the crossmember 5 and the loading L borne by the trolley 6 (and optionally depending upon further variables), therefore, deformations of the container bridge 1 occur. When for examplesee
[0079] In Step S5, the crane controller 12 then corrects the target location xK determined in Step S3 taking into account the deformations of the container bridge 1 determined in Step S4. As a rule, one single correction will be completely sufficient. Alternatively, as indicated by dashed lines in
[0080] Following correction of the target location xK, the crane controller 12 moves onto Step S6. In Step S6, the crane controller 12 positions the trolley 6 at the target location xK determined in Step S5. Theni.e. after positioning the trolley 6 at its target location xKin Step S7, the crane controller 12 lowers the load 8 (with or without containers 9) onto the load handling point 10, 11. If the load handling point 10, 11 is the mobile load handling point 11, furthermore, the load handling point 11 is positioned at its target location xL before the execution of Step S7. If the load handling point 11 is controlled by the crane controller 12, the corresponding positioning according to
[0081] Although the positioning of the load handling point 11 at its target location xL has to be performed before the execution of Step S7, it does not necessarily have to be performed immediately before the execution of Step S7. Therefore, Step S8 can be executed at any point within the sequence S1 to S7. However, it does have to be executed before Step S7.
[0082] In the context of the above explanations for
[0083] According to
[0084] In a Step S13analogously to Step S3 in
[0085] In a Step S14,similarly to Step S4 in
[0086] In Step S15, the crane controller 12 then corrects the target location xL determined in Step S13 taking into account the deformations of the container bridge 1 determined in Step S14. In the context of Step S15, one single correction results in an ideal correction.
[0087] Following the correction of the target location xL, the crane controller 12 moves onto Step S16. In Step S16, the crane controller 12 positions the mobile load handling point 11 to the target location xL determined in Step S15. Theni.e. after positioning the mobile load handling point 11 at its target location xLin Step S17, the crane controller 12 lowers the spreader 8 (with or without containers 9) onto the mobile load handling point 11.
[0088] Furthermore, before the execution of Step S17 by the crane controller 12, in a Step S18, the trolley 6 is positioned at its target location xK. The positioning of the trolley 6 at its target location xK has to be performed before the execution of Step S17. However, it does not necessarily have to be performed immediately before the execution of Step S17. Therefore, the Step S18 can be executed at any point within the sequence S11 to S17. However, it does have to be executed before Step S17.
[0089] In the context of the procedure in
[0090] In the context of the embodiment in
[0091] According to
[0092] In a Step S23similarly to Step S4 in
[0093] In the context of the procedure in
[0094] In the context of the embodiment in
[0095] According to
[0096] In a Step S33similarly to Step S4 in
[0097] In a Step S37, the crane controller 12 determines the deviation of the actual location xL determined of the mobile load handling point 11 from the target location xL of the mobile load handling point 11. In a Step S38, the crane controller 12 determines, depending on the deviation determined in Step S37, control commands S for the positioning of the mobile load handling point 11. Furthermore, a corresponding actuation the mobile load handling point 11 is performed in a Step S39.
[0098] Steps S31 to S39 are often incorporated in a repeatedly executed control loop. Solely for reasons of clarity, this is not shown in
[0099] In the above explanation, the correction of the target locations xK, xL and the actual location xL is restricted to the direction of movement of the trolley 6. However, the above-explained procedures can be automatically extended to orthogonal horizontal direction thereto. The corresponding procedures are exactly the same as the above-described procedures. It is also possible to apply similar procedures with respect to the lowering of the load 8. This is explained in more detail below in conjunction with
[0100]
[0101] According to
[0102] In a Step S42, the crane controller 12 determines, based on the deformations of the container bridge 1, a correction value for the target height h. Step S42 can be part of Step S4 in
[0103] Following the correction of the target height h, Step S7 in
[0104] In the context of the procedure in
[0105] Similarly to the embodiment in conjunction with
[0106] According to
[0107] In a Step S53, the crane controller 12 determinessimilarly to Step S4 in
[0108] In order to determine the deformations of the container bridge 1 dependent on the location of the trolley 6 and the loading of the trolley 6, the crane controller 12 implements a model 17 according to
[0109] The model 17 uses the input variables supplied to it to determine a state of deformation V. The state of deformation V can be used to determine a wide variety of correction quantities, for example changes to the positioning and/or orientation of the sensors 16 and a change to the position of the trolley 6 in the horizontal and vertical direction. Changes to the positioning and/orientation of the sensors 16 can, for example, be used to determine the corresponding correction quantities M1, M2, M3 when the model 17 is supplied with the first acquisition location x1 and the first acquisition loading L1 or the second acquisition location x2 and the second acquisition loading L2 or the third acquisition location x3 and the third acquisition loading L3 as input variables. A change to the position of the trolley 6 in the horizontal direction can be used to correct the target location xL of the load handling point 10, 11 or to correct the target location xK of the trolley 6 when the model 17 is supplied with the target location xK of Step S3 in
[0110] The model 17 as such can, for example, comprise a correction table 17a. In this case, the correction table 17a has a multi-dimensional structure, namely one dimension per input variable. Although the correction table 17a is only defined for specific support points, linear or nonlinear interpolation between support points is possible in a manner that is known per se. Alternatively, the model 17 can be embodied as a rod support model 17b of the container bridge 1. In another alternative, the model 17 can be embodied as a model 17c of the container bridge 1 based on finite elements. Further embodiments and combinations of the models 17a, 17b, 17c are also possible.
[0111] In the above description, the correction is furthermore performed exclusively using a respective location xK, x1, x2, x3 of the trolley 6 and the respective associated loading L, L1, L2, L3 of the trolley 6. However, where the determination of correction quantities M1, M2, M3 for the measured values M1, M2, M3 acquired by the sensors 16 is concerned, it is possible for the crane controller 12always related to the respective acquisition time point t1, t2, t3to take account of further variables. These variables can, for example, according to the depiction in
[0116] To summarize, the present invention hence relates to the following:
[0117] A handling system comprises a bridge 1 arranged on a substrate 3 container and at least one load handling point 10, 11 arranged on the substrate 3. The container bridge 1 has a trolley 6 which can be moved on a crossmember 5 of the container bridge 1 relative to the substrate 3. A crane controller 12 matches a target location xK of the trolley 6 related to the crossmember 5 and a target location xL of the load handling point 10, 11 related to the substrate 3 to one another in such a way that, when the target load 8 is lowered at the target location xK of the trolley 6, the target load 8 is lowered onto the target location xL of the load handling point 10, 11. The matching is performed while additionally taking into account at least one target loading L with which the trolley 6 is loaded at its target location xK. The crane controller 12 positions the trolley 6 at its target location xL. Furthermore, said crane controller, after positioning the trolley 6, lowers the target load 8 onto the load handling point 10, 11. If the load handling point 11 can be moved on the substrate 3 and the load handling point 11 is controlled by the crane controller 12, the crane controller 12 further positions the load handling point 11 at its target location xL before lowering the target load 8 onto the load handling point 11.
[0118] The present invention has many advantages. In particular, highly accurate positioning of the trolley 6 relative to the load handling point 10, 11 is possible in a simple and reliable manner. Furthermore, it is automatically possible to retrofit an existing crane controller known from the prior art.
[0119] Although the invention has been illustrated and described in greater detail by the preferred exemplary embodiment, the invention is not restricted by the disclosed examples and other variations can be derived herefrom by the person skilled in the art without departing from the scope of protection of the invention.