Method for optimizing anti-swing function
By synchronizing mathematical models in real time in the control device, the problems of anti-swing system accuracy and performance in harsh environments are solved, and efficient anti-swing control is achieved.
Patent Information
- Application Number
- CN202380061880.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-07-05
- Filing Date
- 2023-06-16
- Publication Date
- 2025-04-04
AI Technical Summary
The prior art is difficult to implement high-precision, high-performance anti-swing systems in harsh environments, especially in the absence of precise angle measurements.
By obtaining the angle measurement of the load relative to the crane in the control device, applying a filter to calculate the difference between the model curve and the measurement curve, synchronizing the mathematical model in real time, thereby optimizing the model of anti-swing function.
It realizes efficient anti-swing in harsh environments, and can provide high-precision control without precise angle measurements, reducing the possibility of model calculation errors.
Smart Images
Figure CN119768359A_ABST
Abstract
Description
Technical Field
[0001] The present invention generally relates to a method for an anti-sway function applied to a lifting apparatus across a warehouse, the lifting apparatus being arranged for carrying a load suspended by cables from a trolley which can be moved together with the lifting apparatus. Background Art
[0002] like Figure 1 As shown, a lifting device 1 such as a bridge crane, a gantry crane or an overhead traveling crane typically comprises a trolley 2 that can move along a horizontal axis Y on a single beam or a set of rails 3. This first movement along the Y axis is typically referred to as a short stroke movement and / or a trolley movement. Depending on the type of device, the beam or the set of rails 3 (also referred to as a bridge) can also move along a horizontal axis X perpendicular to the Y axis, thereby enabling the trolley to move along the X and Y axes. This second movement along the X axis is typically referred to as a long stroke movement and / or a bridge, crane or gantry movement. The amount of effective short stroke along the Y axis and effective long stroke along the X axis determines the lifting area spanned by the crane 1.
[0003] The tool 4, also called load suspension means, is associated with a cable system with a cable passing through the trolley 2, the length of the cable 5 being controlled by the trolley 2 to vary, thereby enabling the load 6 to be moved along a vertical axis Z, called a lifting movement.
[0004] Transferring a suspended load across warehouses, halls, shipyards, metallurgical plants or nuclear power plants requires the operator to be extremely careful to prevent persons, obstacles or objects present in the lifting area from being struck or damaged in any way. Therefore, in addition to size, the swing of a suspended load, often referred to as sway, is something the operator needs to take into account when maneuvering the load across the workplace along a trajectory within the boundaries of the lifting area.
[0005] This complexity has hampered the development of fully automated lifting systems that can independently transfer suspended loads along the track. Some advanced anti-sway features are difficult and time-consuming to implement, primarily because each crane has a large number of variable, specific parameters.
[0006] There are already various solutions to the sway problem, which can be selected based on the desired accuracy, environmental conditions (rain, snow, dust, etc.) or targeted performance.
[0007] In heavy industrial plants, overhead cranes are necessary to move heavy loads. For reasons of economy and efficiency, these companies implement anti-sway systems on their overhead cranes to facilitate handling operations, improve the quality of their finished products, and reduce mechanical constraints on the cranes, thus avoiding premature wear of mechanical components.
[0008] To achieve an anti-sway system that provides high accuracy, high performance and can work in harsh environments, a first solution is to use a closed loop with sensors that provide better accuracy and performance, and a second solution is to use an open loop without sensors, allowing for harsh environments.
[0009] However, for the first solution, no sensor is able to operate at high temperatures (ambient temperatures over 100°C) for example in steel plants. Moreover, most sensors are based on optical technology (laser / infrared), so they are sensitive to dust, snow, heavy rain, flying objects (such as plastic bags in the waste treatment industry). Furthermore, the installation of sensors is sometimes impossible because there is no energy available at the location or no available location allows operation without any damage to the sensor.
[0010] For the second solution, the accuracy and performance issues of the open-loop system are mainly due to the impossibility of modeling external behaviors, such as:
[0011] -Sway at the start of the movement
[0012] - Sway caused by wind on outdoor cranes
[0013] -Sway caused by mechanical behavior (rolling)
[0014] - The sway caused by the load geometry during movement (mass distribution)
[0015] -Swaying during load removal
[0016] -Swaying caused by handling tools
[0017] All of these behaviors can cause the model to be out of sync with reality: this can be periodic or due to overestimation or underestimation of the angle magnitude.
[0018] Therefore, there is a need to realize an anti-sway system that provides high precision, high performance and is capable of operating in harsh environments. Summary of the invention
[0019] This Summary is provided to introduce concepts related to the claimed subject matter. This Summary is not intended to identify essential features of the claimed subject matter, nor is it intended to be used to determine or limit the scope of the claimed subject matter.
[0020] In one embodiment, there is provided a method for optimizing a model used in real time by an anti-sway function for transporting a load by a lifting device, the lifting device spanning a lifting area and comprising a gantry and a trolley, the trolley being able to transport a load suspended to a lifting mechanism carried in the trolley, wherein when transported the load exhibits a primary sway, the model comprising a model curve representing a theoretical primary sway of the load over time, the method comprising in a control device:
[0021] Obtaining angular measurements of the load relative to the trolley to produce a measurement curve representing the primary sway of the load,
[0022] applying a first filter to the measurement curve to obtain a first filtered measurement curve,
[0023] calculating a first time difference between the model curve and the first filtered measurement curve,
[0024] applying a second filter to the first measurement curve to obtain a second filtered measurement curve,
[0025] Calculate a second difference in maximum angular amplitude between the model curve and the second filtered measurement curve,
[0026] The models are synchronized based on the first calculated difference or the second calculated difference.
[0027] Advantageously, a new architecture for anti-sway control is provided that combines sensor measurements with models typically used in an open loop structure, capable of working in harsh environments, even without precise angle measurements. The anti-sway control can use an analog signal that has the value of the primary sway and is free of any other unwanted information (secondary sway, vibrations, etc.).
[0028] The sway model can provide a very clear and useful sway picture over a short period of time. But after a longer period of time, the model calculations may be wrong (in amplitude or offset) due to parameter inaccuracies, e.g. related to harsh environments. Thanks to the measured signal (after filtering), it is possible to resynchronize the model in real time.
[0029] Advantageously, the method can be implemented for a specific architecture of an anti-sway function in an automation system. The specificity is that the function is centered around a digital sway model and the adjustments are made based on this digital sway.
[0030] In fact, the mathematical model can be synchronized using already available information, which may be only significant points. In fact, the mathematical model can be resynchronized with only one significant point, such as zero angle or maximum angle.
[0031] In an embodiment, the models are synchronized based on the first calculated difference by applying a time correction corresponding to the first calculated difference.
[0032] In an embodiment, the model is synchronized based on the second calculated difference by applying an amplitude correction corresponding to the second calculated difference.
[0033] In one embodiment, the first filter and the second filter are first order low pass filters.
[0034] In one embodiment, the first filter is provided with a delay slightly higher than the period of the secondary swing of the load.
[0035] In an embodiment, the second filter is provided with a delay that is less than a period of the secondary swing of the load.
[0036] In an embodiment, the first filter and the second filter are dynamic filters.
[0037] In an embodiment, the first filter and the second filter are dynamically set with a delay that depends on the secondary swing of the load.
[0038] In another embodiment, there is provided an apparatus for optimizing a model used in real time by an anti-sway function for transporting a load by a lifting apparatus, the lifting apparatus spanning a lifting area and comprising a gantry and a trolley, the trolley being capable of transporting a load suspended to a lifting mechanism carried in the trolley, wherein when transported the load exhibits a primary sway, the model comprising a model curve representing a theoretical primary sway of the load over time, the apparatus comprising:
[0039] one or more network interfaces for communicating with a telecommunications network;
[0040] a processor coupled to the network interface and configured to execute one or more processes; and
[0041] A memory configured to store a process executable by the processor, the process being operable when executed to:
[0042] Obtaining angular measurements of the load relative to the trolley to produce a measurement curve representing the primary sway of the load,
[0043] applying a first filter to the measurement curve to obtain a first filtered measurement curve,
[0044] calculating a first time difference between the model curve and the first filtered measurement curve,
[0045] applying a second filter to the first measurement curve to obtain a second filtered measurement curve,
[0046] Calculate a second difference in maximum angular amplitude between the model curve and the second filtered measurement curve,
[0047] The models are synchronized based on the first calculated difference or the second calculated difference.
[0048] In another embodiment, a computer readable medium is provided on which is embodied a computer program for executing a method for optimizing a model used in real time by an anti-sway function for transporting a load by a lifting device. The computer program comprises instructions for executing the steps of the method according to the invention. BRIEF DESCRIPTION OF THE DRAWINGS
[0049] The detailed description is described with reference to the accompanying drawings. In the drawings, the left-most digit(s) of a reference number identifies the drawing in which the reference number first appears. The same numerals are used to refer to similar features and components throughout the drawings. Some embodiments of systems and / or methods according to embodiments of the present subject matter are now described, by way of example only, and with reference to the accompanying drawings, in which:
[0050] Figure 1 An example of a lifting device is schematically shown;
[0051] Figure 2 An example of a communication system for optimizing an anti-sway algorithm for transporting a load by a lifting device is schematically shown;
[0052] Figure 3 A representation of the main swing over time is shown;
[0053] Figure 4a shows a representation of a measured curve of the main sway, a model curve of the main sway, and a first filtered measured curve;
[0054] Figure 4b shows a representation of a first filtered measurement curve added to a measurement curve of a main sway and a model curve of the main sway for synchronization of the model curve;
[0055] Figure 5a Another representation of a measured curve of the main sway, a model curve of the main sway, and a second filtered measured curve is shown;
[0056] Figure 5b Another representation of a second filtered measurement curve added to the measurement curve of the main sway and a model curve of the main sway is shown for synchronization of the model curve;
[0057] Figure 6 A flow chart illustrating a method for optimizing a model used by an anti-sway function for transporting a load by a lifting apparatus according to one embodiment is shown.
[0058] The same reference number represents the same element or the same type of element on all drawings.
[0059] Those skilled in the art will appreciate that any block diagram herein represents a conceptual diagram of an illustrative system embodying the principles of the subject matter. Similarly, it will be understood that any flow charts, flow diagrams, state transition diagrams, pseudocodes, etc. represent various processes that can be substantially represented in a computer-readable medium and executed by a computer or processor, whether or not such a computer or processor is explicitly shown. DETAILED DESCRIPTION
[0060] The accompanying drawings and the following description illustrate specific exemplary embodiments of the present invention. Therefore, it should be understood that those skilled in the art will be able to design various arrangements that, although not explicitly described or shown herein, embody the principles of the present invention and are included within the scope of the present invention. In addition, any examples described herein are intended to aid in understanding the principles of the present invention and should be interpreted as not being limited to these specifically enumerated examples and conditions. Therefore, the present invention is not limited to the specific embodiments or examples described below, but is defined by the claims and their equivalents.
[0061] refer to Figure 2 , a communication system for optimizing the anti-sway function of a load transported by a lifting device comprises a control device CD, an angle sensor AS and a monitoring system SUP.
[0062] Hoisting areas such as warehouses, yards, halls or other working areas are provided with a monitoring system SUP, which is an IT control system for monitoring the hoisting area. The monitoring system provides information to the control device CD for track enforcement, authorization (ie access management) and overall security.
[0063] The control device CD can communicate with the monitoring system SUP and the angle sensor AS via a telecommunication network TN. The telecommunication network can be a wired or wireless network, or a combination of wired and wireless networks. The telecommunication network can be associated with a packet network, such as an IP (“Internet Protocol”) high-speed network, such as the Internet or an intranet, or even a company-specific private network. The control device CD can be a programmable logic controller (PLC) and other automation devices capable of implementing an industrial process and capable of communicating with the monitoring system to exchange data (such as requests, inputs, control data, etc.).
[0064] An angle sensor AS may be connected to the trolley and is configured to measure the angle of the load relative to the trolley, ie the angle between the load and the vertical axis. The angle sensor AS reports the measured angle to the control device CD.
[0065] The control device CD is configured to create a path followed by the crane to transport the load from one place to another within the lifting area. Typically, during the operation of the overhead crane, an anti-sway algorithm is used to damp the sway of the load, which provides an improvement in the performance of the mechanism and reduces the risk of accidents and injury situations. Methods used to achieve this goal may include mathematical models and computer simulations.
[0066] Some anti-sway systems in closed loop may be based on the use of load angle sensors. For example, the anti-sway algorithm takes as input the dynamic parameters of the lifting equipment, including the current position of the trolley and the current angle of the load relative to the trolley. For anti-sway systems in open loop, the anti-sway algorithm is based on a mathematical model and does not use data from sensors (e.g., angle sensors). In one embodiment, the anti-sway algorithm uses data from the angle sensor to adjust the mathematical model, which may be out of sync with reality, for example in time or amplitude.
[0067] The control device CD is configured to determine a significant point that can be used to optimize the anti-sway function by resynchronizing the mathematical model with at least one determined significant point. To this end, the control device calculates the deviation from the mathematical model and the filtered measurement at the significant point of the mathematical model using a filter applied to the angle measured by the angle sensor.
[0068] refer to Figure 3 , which represents the primary sway of the suspended load along the axis along which the suspended load moves. During the transport of the load, the control device uses a mathematical model in real time to track the theoretical sway of the load over a period of time. As the trolley travels, the suspended load assumes an angle with respect to the X-axis or the Y-axis, corresponding to the primary sway. The mathematical model gives the amplitude of the sway with respect to time. The angle sensor gives the amplitude of the sway measurement with respect to time. The sway measurement corresponds to the raw value of the disturbance sway measurement.
[0069] The raw values of the perturbation sway measurement show the variation of the perturbation which may be due to at least secondary sway (medium frequency) and mechanical vibration (high frequency). When the model is synchronized with reality, the curve of the sway measurement is superimposed on the curve of the model. When the model is out of sync with reality, periodic out-of-sync or over- or underestimation of the angular amplitude may occur.
[0070] refer to Figure 4a , which represents the measured curve obtained from the measurement of the main sway (angle) of the suspended load given by the angle sensor and the model curve of the mathematical model of the main sway. After the measurement, a periodic filter is applied, which means a time delay (0.3 seconds in this example).
[0071] The periodic filter is a low-pass filter used to eliminate variations due to secondary sway. Secondary sway phenomena may occur when the winding system distance is small, which more or less corresponds to the cable length between the trolley and the tool. Secondary sway phenomena may also depend on the global equivalent center of gravity.
[0072] The difference between primary and secondary sway will be quickly explained below. In the case of primary sway, the load can be balanced in an arc below the trolley from a vertical axis in a direction parallel to the direction of travel of the trolley. The axis of rotation is located around the upper part of the winding system connected to the trolley. In the case of secondary sway, the tool can be further balanced in an arc below the trolley from an axis of the global equivalent center of gravity in a direction parallel to the direction of travel of the trolley. The axis of rotation is located between the lower part of the winding system connected to the tool and the center of gravity of the load.
[0073] The configuration of the periodic filter depends on the period of the secondary sway. Since the secondary sway may vary and depend on the length of the cable, the configuration of the periodic filter may be dynamic and depend on the current length of the cable.
[0074] In one embodiment, the periodic filter is set with a delay slightly higher than the period of the secondary swing. In one example, the period of the secondary swing is 0.25 seconds and the delay of the periodic filter is set to 0.3 seconds. This configuration allows accurate time offset, although the curve of the filtered measurement loses accuracy in amplitude.
[0075] The image below shows a zoom-in in the area bounded by the rectangle. The period filter provides a time delay of 0.3 seconds, which can be clearly seen when the angle of the main swing equals zero.
[0076] Then, the difference between the filtered measurement and the mathematical model at a significant point, such as zero angle (swing null), can be calculated. Since the expected delay is known, if the calculated difference is different from the expected delay, the mathematical model can be shifted based on the calculated difference. In this example, the curve of the measurement of the main swing follows the curve of the mathematical model and is therefore considered to be synchronized.
[0077] refer to Figure 4b , shows the measured curve of the main sway of the suspended load, the model curve of the mathematical model of the main sway and the filtered curve of the filtered measurement with an adaptive filter. The measured curve does not follow the model curve of the mathematical model (modeled sway) and is therefore considered to be out of sync.
[0078] The figure below shows a zoom-in in the area bounded by the rectangle. Since the normal value should be 0.3 seconds, this means that the mathematical model is ahead of the difference, i.e. 0.2 seconds. The mathematical model can then be resynchronized by shifting it in time by the value of 0.2 seconds. For example, synchronization can be performed once the angle of the filtered measurement is equal to zero, allowing the difference between the filtered measurement and the mathematical model to be calculated.
[0079] refer to Figure 5a , which represents the measured curve of the measurement of the main sway (angle) of the suspended load given by the angle sensor and the model curve of the mathematical model of the main sway. After the measurement, an amplitude filter is applied, which means a time delay (0.1 seconds in this example).
[0080] The amplitude filter is a low-pass filter which is arranged to partially eliminate variations due to "disturbance caused by mechanical vibration (high frequency)".
[0081] The configuration of the amplitude filter depends on the period of the secondary sway. Since the secondary sway may vary and depend on the length of the cable, the configuration of the amplitude filter may be dynamic and depend on the current length of the cable.
[0082] In one embodiment, the amplitude filter is provided with a delay included in the period of the secondary oscillation. In one embodiment, the amplitude filter is provided with a delay included between one quarter and one half of the period of the secondary oscillation. In one example, the period of the secondary oscillation is 0.25 seconds and the delay of the amplitude filter is set to 0.1 seconds. This configuration allows for precise amplitude offsets, although there are still variations in the measured curve.
[0083] The figure below shows a zoom-in in the area bounded by the rectangle. The amplitude filter provides a time delay of 0.1 seconds, which can be clearly seen when the angle of the main sway is maximum (almost 1.8°).
[0084] If the maximum value of the mathematical model differs from the value of the filtered measurement, the model is out of sync and an amplitude correction is required.
[0085] Then, the difference between the filtered measurement and the mathematical model at a significant point, such as the maximum angle (sway maximum), can be calculated. If the calculated difference is not null, the mathematical model can be shifted based on the calculated difference. In this example, the measured curve of the main sway follows the curve of the mathematical model in amplitude and is therefore considered to be synchronized.
[0086] refer to Figure 5b , shows the measured curve of the main sway of the suspended load, the model curve of the mathematical model of the main sway and the filtered curve of the filtered measurement with an adaptive filter. The measured curve does not follow the model curve of the mathematical model in amplitude and is therefore considered to be out of sync.
[0087] The figure below shows a zoom-in in the area bounded by the rectangle. The value of the filtered measurement of the amplitude angle and the value of the amplitude angle of the mathematical model present a difference of "-0.46°". Just after calculating this difference (indicated by the double arrow), the mathematical model is corrected in amplitude by applying the calculated difference.
[0088] refer to Figure 6 According to one embodiment of the present invention, a method for optimizing a model used by an anti-sway function for transporting a load by a lifting device comprises steps S1 to S7.
[0089] Initially, the control device CD stores the mathematical model and executes an anti-sway algorithm which uses the mathematical model in real time to follow the theoretical sway of the load during transport. The control device CD starts the transport of the load and is configured to determine significant points of the mathematical model for synchronization of the model according to at least one of steps S4 and S7.
[0090] In step S1 , the angle sensor AS performs an angle measurement of the load relative to the trolley. The control device CD acquires the measurements from the angle sensor AS to generate a measurement curve representative of the primary sway.
[0091] The measurement curve contains unwanted information, for example due to secondary oscillations or vibrations.
[0092] In step S2, the control device CD applies a first filter, called period filter PF, to the measurement curve to obtain a first filtered measurement curve. The period filter PF is provided with a delay slightly higher than the period of the quadratic oscillation.
[0093] In a step S3 , the control device CD calculates a first time difference between the model curve and the first filtered measurement curve.
[0094] In step S4, the control device CD synchronizes the model with the first calculated difference by applying a time correction corresponding to the first calculated difference.
[0095] The control device CD can use significant points of the model for synchronization, such as the zero angle of the model curve and the zero angle of the first filtered measurement curve.
[0096] Due to the first filtered measurement curve just after the calculation of the first difference, the model can be resynchronized. The time of resynchronization depends on the significant points of the model curve used and can be determined by the operator.
[0097] In step S5, the control device CD applies a second filter, called amplitude filter AF, to the first measurement curve to obtain a second filtered measurement curve. The amplitude filter is provided with a delay that is smaller than the period of the secondary sway.
[0098] In a step S6 , the control device CD calculates a second difference in maximum angular amplitude between the model curve and the second filtered measurement curve.
[0099] In step S7, the control device CD synchronizes the model with the second calculated difference by applying an amplitude correction corresponding to the second calculated difference.
[0100] The order of steps S2-S4 and S5-S7 is interchangeable, representing two possibilities for model resynchronization.
[0101] One embodiment includes a control device CD in the form of an apparatus, which includes one or more processors, an I / O interface and a memory coupled to the processor. The processor can be implemented as one or more microprocessors, microcomputers, microcontrollers, digital signal processors, central processing units, state machines, logic circuits and / or any device that manipulates signals based on operating instructions. The processor can be a single processing unit or multiple units, all of which can also include multiple computing units. Among other capabilities, the processor is configured to obtain and execute computer-readable instructions stored in the memory.
[0102] The functions implemented by the processor can be provided by using dedicated hardware as well as hardware capable of executing software associated with appropriate software. When provided by a processor, these functions can be provided by a single dedicated processor, a single shared processor, or multiple individual processors, some of which can be shared. In addition, the explicit use of the term "processor" should not be interpreted as referring exclusively to hardware capable of executing software, and may implicitly include, but is not limited to, digital signal processor (DSP) hardware, network processors, application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), read-only memories (ROMs), random access memories (RAMs), and non-volatile memories for storing software. Other hardware that is conventional and / or customized may also be included.
[0103] The memory may include any computer-readable medium known in the art, including, for example, volatile memory, such as static random access memory (SRAM) and dynamic random access memory (DRAM), and / or non-volatile memory, such as read-only memory (ROM), erasable programmable ROM, flash memory, hard disk, optical disk, and magnetic tape. The memory includes modules and data. Modules include routines, programs, objects, components, data structures, etc. that perform specific tasks or implement specific abstract data types. Data is particularly used as a repository for storing data processed, received, and generated by one or more modules.
[0104] Those skilled in the art will readily recognize that the steps of the above method can be performed by a programmed computer. Some embodiments herein are also intended to cover program storage devices, such as digital data storage media, which are machine or computer readable and encode a machine-executable or computer-executable program of instructions, wherein the instructions perform some or all of the steps of the described method. The program storage device may be, for example, a digital memory, a magnetic storage medium such as a disk and tape, a hard drive, or an optically readable digital data storage medium.
[0105] Although the present invention has been described above with reference to specific embodiments, the present invention is not limited to the specific forms set forth herein. On the contrary, the present invention is limited only by the appended claims, and within the scope of these appended claims, other embodiments besides the specific embodiments described above are also possible.
[0106] In addition, although exemplary embodiments have been described above in some exemplary combinations of components and / or functions, it should be understood that alternative embodiments may be provided by different combinations of components and / or functions without departing from the scope of the present disclosure. In addition, it is specifically contemplated that specific features described separately or as part of an embodiment may be combined with other separately described features or parts of other embodiments.
Claims
1. A method for optimizing a model used in real time by an anti-sway function for transporting a load by a lifting device, the lifting device spanning a lifting area and comprising a gantry and a trolley capable of transporting a load suspended to a lifting mechanism carried in the trolley, wherein, When transported, the load exhibits a primary sway, the model comprises a model curve representing a theoretical primary sway of the load over time, the method comprising in a control device (CD): obtaining (S1) an angular measurement of the load relative to the trolley to produce a measurement curve representative of the primary sway of the load, applying (S2) a first filter to the measurement curve to obtain a first filtered measurement curve, calculating (S3) a first time difference between the model curve and the first filtered measurement curve, applying (S5) a second filter to the first measurement curve to obtain a second filtered measurement curve, calculating (S6) a second difference in maximum angular amplitude between the model curve and the second filtered measurement curve, The models are synchronized (S4; S7) based on the first calculated difference or the second calculated difference.
2. The method according to claim 1, wherein: The models are synchronized based on the first calculated difference by applying a time correction corresponding to the first calculated difference.
3. A method according to any one of the preceding claims, wherein: The models are synchronized based on the second calculated difference by applying an amplitude correction corresponding to the second calculated difference.
4. A method according to any one of the preceding claims, wherein: The first filter and the second filter are first order low pass filters.
5. A method according to any one of the preceding claims, wherein: The first filter is provided with a delay slightly higher than the period of the secondary swing of the load.
6. A method according to any one of the preceding claims, wherein: The second filter is provided with a delay that is less than a period of a secondary swing of the load.
7. A method according to any one of the preceding claims, wherein: The first filter and the second filter are dynamic filters.
8. The method according to any one of claims 5 to 7, wherein: The first filter and the second filter are dynamically set with a delay depending on a secondary swing of the load.
9. A device for optimizing a model used in real time by an anti-sway function for transporting a load by a lifting device, the lifting device spanning a lifting area and comprising a gantry and a trolley capable of transporting a load suspended to a lifting mechanism carried in the trolley, wherein When transported, the load exhibits a primary sway, the model comprises a model curve representing the theoretical primary sway of the load over time, the apparatus comprising: one or more network interfaces for communicating with a telecommunications network; a processor coupled to the network interface and configured to execute one or more processes; and A memory configured to store a process executable by the processor, the process being operable when executed to: Obtaining angular measurements of the load relative to the trolley to produce a measurement curve representing the primary sway of the load, applying a first filter to the measurement curve to obtain a first filtered measurement curve, calculating a first time difference between the model curve and the first filtered measurement curve, applying a second filter to the first measurement curve to obtain a second filtered measurement curve, A second difference in maximum angular amplitude between the model curve and the second filtered measurement curve is calculated, and the model is synchronized based on the first calculated difference or the second calculated difference.
10. A computer readable medium having embodied thereon a computer program for executing the method according to any one of claims 1 to 8 for optimizing a model used in real time by an anti-sway function for transporting a load by a lifting device.