Apparatus and method for determining an initial opening degree for a valve regulating the supply of hydraulic fluid to a slewing drive of a lifting device, lifting device and vehicle

Abstract

Provided is an apparatus (100) for determining an initial opening degree for a valve (175) regulating the supply of hydraulic fluid to a slewing drive (180) of a lifting device (150) to initiate a slewing motion of a crane arm of the lifting device. The apparatus comprises processing circuitry (110) configured to receive first input data (101) indicating an inclination measured at the lifting device. Additionally, the apparatus is configured to receive second input data (102) indicating a measured pressure in a hydraulic cylinder (165) of the crane arm (160). The apparatus is additionally configured to determine the initial opening degree for the valve based on the first and second input data.

Description

[0001] APPARATUS AND METHOD FOR DETERMINING AN INITIAL OPENING DEGREE FOR A VALVE REGULATING THE SUPPLY OF HYDRAULIC FLUID TO A SLEWING DRIVE OF A LIFTING DEVICE, LIFTING DEVICE AND VEHICLE

[0002] Field

[0003] The present disclosure relates to slewing of crane arms. In particular, examples of the present disclosure relate to an apparatus and a method for determining an initial opening degree for a valve regulating the supply of hydraulic fluid to a slewing drive of a lifting device, a lifting device and a vehicle.

[0004] Background

[0005] Cranes, in particular loader cranes, play a pivotal role in various industries, providing efficient lifting and handling capabilities. In many applications, cranes are required to perform slewing operations with high precision and stability, especially when operating on inclined surfaces. Conventional crane slewing systems utilizing hydraulic oil motors face challenges related to leakage, which may adversely affect slewing performance. Specifically, when a crane is inclined, and an upward slewing motion is initiated, leakage in the oil motors may exceed the supplied oil flow, resulting in an unintended downward movement.

[0006] To address this issue, prior approaches have implemented an increased slewing starting value for the main control valve. This method ensures that even at low user input levels, a minimum oil flow is supplied to compensate for leakage. However, such an approach introduces abrupt movements or jerks during slewing initiation, particularly when the crane is positioned on level ground. These jerky movements reduce fine controllability, leading to suboptimal operational performance and user dissatisfaction.

[0007] Hence, there may be a demand for improved crane arm slewing.

[0008] Summary

[0009] This demand is met by an apparatus and a method for determining an initial opening degree for a valve regulating the supply of hydraulic fluid to a slewing drive of a lifting device, a lifting device, a vehicle, a non-transitory machine-readable medium and a program in accord-ance with the independent claims. Further embodiments are defined by the dependent claims.

[0010] According to a first aspect, the present disclosure provides an apparatus for determining an initial opening degree for a valve regulating the supply of hydraulic fluid to a slewing drive of a lifting device to initiate a slewing motion of a crane arm of the lifting device. The apparatus comprises processing circuitry configured to receive first input data indicating an inclination measured at the lifting device. Additionally, the apparatus is configured to receive second input data indicating a measured pressure in a hydraulic cylinder of the crane arm. The apparatus is additionally configured to determine the initial opening degree for the valve based on the first and second input data.

[0011] According to a second aspect, the present disclosure provides a lifting device. The lifting device comprises a crane arm and a hydraulically driven slewing drive for slewing the crane arm. Additionally, the lifting device comprises a hydraulic system configured to generate flow of hydraulic fluid. The hydraulic system comprises a valve for regulating the supply of hydraulic fluid to the slewing drive. Further, the lifting device comprise an apparatus for determining an initial opening degree for the valve to initiate a slewing motion of the crane arm according to the first aspect.

[0012] According to a third aspect, the present disclosure provides a vehicle having mounted thereon a lifting device according to the second aspect.

[0013] According to a fourth aspect, the present disclosure provides a method for determining an initial opening degree for a valve regulating the supply of hydraulic fluid to a slewing drive of a lifting device to initiate a slewing motion of a crane arm of the lifting device. The method comprises receiving first input data indicating an inclination measured at the lifting device. Additionally, the method comprises receiving second input data indicating a measured pressure in a hydraulic cylinder of the crane arm. The method further comprises determining the initial opening degree for the valve based on the first and second input data.

[0014] According to a fifth aspect, the present disclosure provides a non-transitory machine-readable medium having stored thereon a program having a program code for performing the method according to the fourth aspect, when the program is executed on a processor or a programmable hardware.According to a sixth aspect, the present disclosure provides a program having a program code for performing the method according to the fourth aspect, when the program is executed on a processor or a programmable hardware.

[0015] By considering the inclination measured at the lifting device and the pressure in the hydraulic cylinder of the crane, the proposed technology effectively compensates for hydraulic leakage while simultaneously avoiding jerky motion during slewing initiation. Conventional approaches require a fixed high starting value to counteract leakage, which results in abrupt movements and poor fine controllability. In contrast, the proposed technology dynamically determines the valve's initial opening degree based on real-time sensor data, ensuring sufficient hydraulic flow to overcome leakage while allowing for smooth and controlled slewing motion. This results in improved operator control, reduced mechanical stress, and enhanced safety, particularly when operating on inclined surfaces.

[0016] Brief description of the Figures

[0017] Some examples of apparatuses and / or methods will be described in the following by way of example only, and with reference to the accompanying figures, in which

[0018] Fig. 1 illustrates a lifting device together with an exemplary apparatus for determining an initial opening degree for a valve regulating the supply of hydraulic fluid to a slewing drive of the lifting device to initiate a slewing motion of a crane arm of the lifting device;

[0019] Fig. 2 illustrates exemplary courses for the initial opening degrees of the valve over the lateral inclination of the crane arm for clockwise and counterclockwise slewing motion of the crane arm;

[0020] Fig. 3 illustrates an exemplary data flow for determining the initial opening degree for the valve;

[0021] Fig. 4 illustrates an example of a vehicle; and

[0022] Fig. 5 illustrates a flowchart of an example of a method for determining an initial opening degree for a valve regulating the supply of hydraulic fluid to a slewing drive of a lifting device.

[0023] Detailed DescriptionSome examples are now described in more detail with reference to the enclosed figures. However, other possible examples are not limited to the features of these embodiments described in detail. Other examples may include modifications of the features as well as equivalents and alternatives to the features. Furthermore, the terminology used herein to describe certain examples should not be restrictive of further possible examples.

[0024] Throughout the description of the figures same or similar reference numerals refer to same or similar elements and / or features, which may be identical or implemented in a modified form while providing the same or a similar function. The thickness of lines, layers and / or areas in the figures may also be exaggerated for clarification.

[0025] When two elements A and B are combined using an “or”, this is to be understood as disclosing all possible combinations, i.e. only A, only B as well as A and B, unless expressly defined otherwise in the individual case. As an alternative wording for the same combinations, "at least one of A and B" or "A and / or B" may be used. This applies equivalently to combinations of more than two elements.

[0026] If a singular form, such as “a”, “an” and “the” is used and the use of only a single element is not defined as mandatory either explicitly or implicitly, further examples may also use several elements to implement the same function. If a function is described below as implemented using multiple elements, further examples may implement the same function using a single element or a single processing entity. It is further understood that the terms "include", "including", "comprise" and / or "comprising", when used, describe the presence of the specified features, integers, steps, operations, processes, elements, components and / or a group thereof, but do not exclude the presence or addition of one or more other features, integers, steps, operations, processes, elements, components and / or a group thereof.

[0027] Fig. 1 schematically illustrates a lifting device 150. In the example of Fig. 1, the lifting device 150 is depicted as a knuckle boom or loader crane for loading and unloading goods (loads). However, it should be noted that the present disclosure is not limited thereto. The lifting device 150 may in general be any machinery (device) for lifting loads (e.g., goods and / or people) using hydraulic power. For example, the lifting device 150 may be another type of crane such as a mobile crane or a crane section of a mobile crane. In alternative examples, the lifting device 150 may be an elevating work platform (e.g. a crane with a lifting platform).The lifting device 150 comprises a device base 151 and a crane arm 160. The device base 151 may also be understood as a crane base. The device base 151 may form a mounting platform for the crane arm 160 and may allow to mount the crane arm 160 to a lifting device carrier (not illustrated in Fig. 1). The lifting device carrier is a device capable of receiving, holding and supporting the lifting device 150. The lifting device carrier may be a stationary (e.g. non-moving or non-movable) lifting device carrier such as a stationary mounting socket (e.g. platform or structure) or a mobile lifting device carrier such as a vehicle. The vehicle may be a land vehicle (e.g., wheeled, tracked or railed, for example, a truck, a lorry or a crawler) or a watercraft (e.g., a ship, a boat or a barge).

[0028] A crane column 161 of the crane arm 160 and, hence, the crane arm 160 itself is slewable (rotatable) relative to the device base 151 of the lifting device 150. For example, the crane column 161 may be rotatable about a vertical axis z relative to the device base 151. In other words, the crane arm 160 may be rotated both clockwise and counterclockwise relative to the device base 151.

[0029] For slewing (rotating) the crane arm 160 relative to the device base 151, the lifting device 150 comprises a hydraulically driven slewing drive 180. The slewing drive 180 may be integrated into the device base 151 and is mechanically coupled to both the device base 151 and the crane column 161 to enable horizontal rotation of the crane column 161 relative to the device base 151. The slewing drive 180 comprises various components such as, e.g., a slewing ring (bearing), a hydraulic motor 181 and a gear system (e.g., worm gears or spur gears). The hydraulic motor 181 is configured to convert fluid pressure into rotational force. The gear system is configured to transfer the rotational force to the slewing ring, which rotates the crane column 161 mounted thereto and, hence, the crane arm 160.

[0030] A hydraulic system 170 of the lifting device 150 is configured to generate flow of hydraulic fluid. The flow of hydraulic fluid provides hydraulic power for hydraulic actuators of the lifting device 150 such as the slewing drive 180. For example, the hydraulic system 170 may comprise a displacement pump 171 driven by a rotary drive 199 (which may be external to the lifting device 150). The displacement pump 171 is configured to generate (cause) the flow of hydraulic fluid when driven by the rotary drive 199. In general, any type of hydraulic fluid suitable for transmitting power efficiently may be used. For example, the hydraulic fluid may be a mineral oil-based hydraulic fluid or a synthetic hydraulic fluid.

[0031] The slewing drive 180 is driven by the pressurized hydraulic fluid provided by the hydraulic system 170. The hydraulic system 170 comprises a (control) valve 175 for regulating (con-trolling) the supply of hydraulic fluid to the slewing drive 180. In other words, the valve 175 is configured or is controlled to regulate (control) the flow of the hydraulic fluid to the slewing drive 180. Accordingly, the amount of hydraulic power supplied to the slewing drive 180 is regulated (controlled). The hydraulic system 170 may comprise one or more further (control) valves for regulating (controlling) the supply of hydraulic fluid to further hydraulic actuators of the lifting device 150.

[0032] In addition to the crane column 161, the crane arm 160 comprises a first segment 162, a second segment 163 and a third segment 164.

[0033] The first segment 162 may be denoted as main arm segment, main arm, main boom or lifting arm in some examples. The first segment 162 is pivotably attached (mounted) to the crane column 161 of the crane arm 160 such that the first segment 162 is pivotable about a first horizontal pivot axis Pi relative to the crane column 161. The crane arm 160 comprises a first hydraulic (actuation) cylinder 165 to enable (cause, control) pivoting movement of the first segment 162 relative to the crane column 161. The first hydraulic cylinder 165 is attached (mounted) to both the first segment 162 and the crane column 161. The first hydraulic cylinder 165 is controllable (controlled) to provide (exert) a force to move the first segment 162 relative to the crane column 161 about the first horizontal pivot axis Pi.

[0034] The second segment 163 may be denoted as articulated arm segment, articulated arm, outer boom, knuckle-boom, crane arm extension or knuckle arm in some examples. The second segment 163 is pivotably attached (mounted) to the first segment 162 such that the second segment 163 is pivotable about a second horizontal pivot axis P2 relative to the first segment 162. The crane arm 160 comprises a second hydraulic cylinder 166 to enable (cause, control) pivoting movement of the second segment 163 relative to the first segment 162. The second hydraulic cylinder 166 is attached (mounted) to both the second segment 163 and the first segment 162. The second hydraulic cylinder 166 is controllable (controlled) to provide a force to move the second segment 163 relative to the first segment 162 about the second horizontal pivot axis P2.

[0035] The second segment 163 may be extendable as indicated in Fig. 1. That is, the second segment 163 may comprises multiple sections that can be selectively extended or retracted (e.g., by a hydraulic cylinder 158 of the crane arm 160) to adjust the length and, hence, the reach of the second segment 163. For example, one or more extendable or retractable thrust arm segments 168 (denoted as thrust arms, telescopic extension arms, extension arms or extension booms in some examples) may be supported (mounted) in the secondsegment 163 to vary the length of the second segment 163. The sections or thrust arm segments 168 may be arranged concentrically in the second segment 163. However, it is to be noted that the present disclosure is not limited to extendable second segments. In alternative examples, the second segment 163 may be non-variable in length, i.e. , be of fixed length.

[0036] The third segment 164 may be denoted as second outer boom, fly jib or attachment arm. in some examples. The third segment 164 is pivotably attached (mounted) to the second segment 163 such that the third segment 164 is pivotable about a third horizontal pivot axis P3 relative to the second segment 163. The crane arm 160 comprises a third hydraulic cylinder 167 to enable (cause, control) pivoting movement of the third segment 164 relative to the second segment 163. The third hydraulic cylinder 167 is attached (mounted) to both the third segment 164 and the second segment 163. The third hydraulic cylinder 167 is controllable (controlled) to provide a force to move the third segment 164 relative to the second segment 163 about the third horizontal pivot axis P3.

[0037] The third segment 164 may be extendable as indicated in Fig. 1. That is, the third segment 164 may comprises multiple second sections that can be selectively extended or retracted (e.g., by an actuator 159 of the crane arm 160) to adjust the length and, hence, the reach of the third segment 164. For example, one or more extendable or retractable second thrust arm segments 169 (denoted as second thrust arms, second telescopic extension arms, second extension arms or second extension booms in some examples) may be supported (mounted) in the third segment 164 to vary the length of the third segment 164. The second sections or thrust arm segments 169 may be arranged concentrically in the third segment 164. However, it is to be noted that the present disclosure is not limited to extendable third segments. In alternative examples, the third segment 164 may be non-variable in length, i.e., be of fixed length.

[0038] The hydraulic cylinders 158, 159, 165, 166 and 167 are drivable by the hydraulic system 170 for adjusting the geometry of the crane arm 160 (e.g., based on a user input). Analogously to the valve 175 described above, the hydraulic system 170 may comprise a respective (control valve) for regulating (controlling) the supply of hydraulic fluid to the respective hydraulic cylinder 158, 159, 165, 166 or 167.

[0039] It should be noted that the crane arm may comprise more, less or different segments than the segments 162, 163 and 164 illustrated in Fig. 1.In addition to the crane arm 160, the lifting device 150 may comprise further elements such as an outrigger 152 for selectively supporting the lifting device 150 against ground. The outrigger 152 is attached (mounted) to the device base 151. For example, the outrigger 192 may be extendable from the device base 151 (e.g., manually, electrically or hydraulically). The outrigger 152 comprises a vertical telescopic leg (stabilizer leg, support leg, vertical telescopic sub-structure) 153 for selectively supporting the lifting device 150 against the ground. The outrigger 152 comprises a hydraulic cylinder 154 for adjusting a length of the telescopic leg 153 and for adjusting a pressure with which the lifting device 150 is supported against the ground. The hydraulic cylinder 154 is drivable by the hydraulic system 170. Accordingly, the hydraulic system 170 may comprise a (control) valve for regulating (controlling) the supply of hydraulic fluid to the hydraulic cylinder 154. The hydraulic cylinder 154 may be integrated into the telescopic leg 153. The lifting device 150 may comprise a respective outrigger such as the outrigger 152 illustrated in Fig. 1 on both lateral sides of the device base 151. In alternative example, a vehicle having mounted thereon the lifting device 150 may comprise the one or more outriggers rather than the lifting device 150.

[0040] As described above, the valve 175 regulates the supply of hydraulic fluid and, hence, hydraulic power to the slewing drive 180. In particular, the supply of hydraulic fluid to the slewing drive 180 is controlled by controlling an opening degree of the valve 175. The opening degree of the valve 175 is the extent to which the valve is opened to regulate the flow of the hydraulic fluid to the slewing drive 180. The degree of opening determines how much hydraulic fluid can pass through the valve 175, thus controlling the flow rate of the hydraulic fluid, pressure, and ultimately the performance of the slewing drive 180. For example, the opening degree may indicate or represent the position or angle of the valve 175’s movable element (such as a spool or a poppet) relative to its fully closed or fully open position. This degree of opening directly influences the amount of hydraulic fluid that can flow through the valve 175. The opening degree of the valve 175 may also be denoted as “valve deflection”.

[0041] Slewing of the crane arm 160 relative to the device base 151 is controlled by controlling the opening degree of the valve 175. When initiating the slewing motion of the crane arm 160, an initial opening degree is set for the valve 175 to regulate the initial supply of hydraulic fluid to the slewing drive 180. In other words, the initial opening degree is set during the initial phase where the crane arm 160 transitions from rest to movement about the vertical axis z.

[0042] Further illustrated in Fig. 1 is an apparatus 100 for determining the initial opening degree for the valve 175. The apparatus 100 for determining the initial opening degree for the valve175 comprises processing circuitry 110. For example, the processing circuitry 110 may be a single dedicated processor, a single shared processor, or a plurality of individual processors, some of which or all of which may be shared, a digital signal processor (DSP) hardware, an application specific integrated circuit (ASIC), a system-on-a-chip (SOC), a neuro-morphic processor or a field programmable gate array (FPGA). The processing circuitry 110 may optionally be coupled to, e.g., memory such as read only memory (ROM) for storing software, random access memory (RAM) and / or non-volatile memory. For example, the apparatus 100 may comprise memory configured to store instructions, which when executed by the processing circuitry 110, cause the processing circuitry 110 to perform the steps and methods described herein.

[0043] The apparatus 100 may be part of the crane arm 160 and / or the lifting device 150 (e.g., be part of a crane). According to examples, device control circuitry (an equipment controller) 155 for controlling operation of the lifting device 150 may comprise the apparatus 100. In other examples, the apparatus 100 and the device control circuitry 155 may be separate elements of the lifting device 150. In case the lifting device 150 is a crane such as the knuckle boom crane shown in Fig. 1, the device control circuitry 155 may be crane control circuitry (a crane controller) for controlling operation of the crane. In alternative examples, the apparatus 100 may be external to the crane arm 160, i.e. , not be part of the crane arm 160. Similarly, the apparatus 100 may be external to the lifting device 150, i.e., not be part of the lifting device 150. For example, a computing cloud communicatively coupled to the crane arm 160 and / or the lifting device 150 (e.g., via a wireless connection) may comprise or be the apparatus 100. In still other examples, a vehicle having mounted thereon the lifting device 150 may comprise the apparatus 100.

[0044] The processing circuitry 110 is configured to receive first input data 101 indicating (encoded with information about) an inclination measured at the lifting device 150. The first input data 101 provide information about the tilt or angular position of the lifting device 150 or a part there of such as the crane arm 160 relative to a reference plane (e.g., horizontal plane). For example, the lifting device 150 may comprise an inclination sensor 190 configured to measure the tilt or angular position of the lifting device 150 or a part thereof such as the crane arm 160 relative to a reference plane, and generate the first input data 101 based thereon. The inclination sensor 190 may, e.g., be a 2-axis inclination sensor configured to measure inclination about two orthogonal axes. For example, the inclination sensor 190 may be positioned (arranged) at the crane arm 160 (in particular at the crane column 161) such that the first input data 101 indicate the measured inclination of the crane arm 160 (in particular the measured inclination of the crane column 161) about two orthogonal axes. The two orthog-onal axes may be in the horizontal plane. In other examples, the inclination sensor 190 may be positioned (arranged) at the device base 151 such that the first input data 101 indicate the measured inclination of the device base 151 about two orthogonal axes. Again, the two orthogonal axes may be in the horizontal plane. For example, the two orthogonal axes may be the longitudinal and transverse axes (front- to- back and side-to-side) of the lifting device 150.

[0045] The processing circuitry 110 is configured to receive second input data 102 indicating a measured (hydraulic) pressure in a hydraulic cylinder of the crane arm 160, in particular the measured pressure in the hydraulic cylinder 165. The second input data 102 provide information about the load currently being carried or supported by the crane arm 160. The pressure within the crane arm 160’s hydraulic cylinders 165, 166 and 167 correlates directly with the weight of the load being handled. Higher pressure indicates a heavier load, while lower pressure suggests a lighter load. Furthermore, the pressure within the crane arm 160’s hydraulic cylinders 165, 166 and 167 correlates with the geometry of the crane arm 160. For example, the lifting device 150 may comprise a pressure sensor 195 configured to measure the pressure in a hydraulic cylinder of the crane arm 160, in particular the pressure in the hydraulic cylinder 165, and generate the second input data 102 based thereon.

[0046] The processing circuitry 110 may receive the first and second input data 101 and 102 (and optionally also further input data) directly from the respective sensor or from an intermediate entity such as a buffer memory.

[0047] The processing circuitry 110 is configured to determine (calculate) the initial opening degree for the valve 175 based on the first and second input data 101 and 102. In other words, the processing circuitry 110 determines an optimized valve position to initiate the slewing motion based on the inclination and load (pressure) data 101 and 102.

[0048] The hydraulic motor 181 in the slewing drive 180 experiences internal leakage, particularly when slewing upwards against an incline. When a crane arm is inclined, leakage in the hydraulic motor 181 may cause unintended downward movement if the applied force is insufficient. The apparatus 100 compensates for leakage by adjusting the initial opening degree for the valve 175 to ensure enough hydraulic fluid is supplied to prevent unintended downward movement while maintaining smooth operation. By taking into account both inclination and load (pressure), the apparatus 100 ensures that the hydraulic fluid supply is sufficient to overcome internal leakage in the hydraulic motor 181 while preventing excessive flow. Conventional systems use fixed starting values, which may result in sudden surges of motion(jerks) or insufficient force to initiate movement, leading to stalling or unintended movement. The adaptive approach according to the present disclosure ensures smooth acceleration of the crane arm 160, leading to improved fine control and safety. The apparatus 100 allows to dynamically adjust the initial opening degree for the valve 175 to match the lifting device 150’s operational conditions, leading to precise and gradual slewing movements. This is especially beneficial when handling delicate loads or operating in confined spaces where precision is important. By preventing sudden, jerky movements at the start of slewing, the apparatus 100 reduces the risk of instability, load swinging, and structural stress on the lifting device 150. Operators may confidently initiate slewing motions without the risk of unexpected movements. The apparatus 100 allows to continuously adapt the initial opening degree for the valve 175 to different working conditions (e.g., inclination of the lifting device 150, load changes) without requiring manual adjustments, making operations more efficient and user-friendly.

[0049] The processing circuitry 110 may be configured to continuously (permanently) determine the initial opening degree for the valve 175 over time (e.g., during operation of the lifting equipment 150). In other words, instead of calculating the initial opening degree for the valve 175 once and using it as a fixed value, the processing circuitry 110 continuously receives the first and second input 101 and 102, and updates the initial opening degree for the valve 175. In these examples, the lifting device 150's condition is monitored in real-time to adaptively adjust the initial opening degree for the valve 175. This allows to ensure that the initiation of the slewing motion remains smooth, efficient, and adaptable to changing conditions over time. For example, the continuous determination of the initial opening degree for the valve 175 may be a background process such that an up-to-date initial opening degree for the valve 175 is available whenever a user or operator makes a user input for slewing the crane arm 160.

[0050] For example, the device control circuitry 155 may receive user input data 107 indicating a user input for slewing the crane arm 160 (clockwise or counter-clockwise). The received user input defines the operator's desired slewing action (e.g., direction, speed, and duration of movement). For example, the user input data 107 may be received from a remote control (not illustrated in Fig. 1). The remote control is a device for the operator of the lifting device 150 for controlling the lifting device 150, in particular the crane arm 160 from a distance. However, the present disclosure is not limited thereto. In other examples, the user input data 107 may be received from another entity such as an element or circuitry of the crane arm 160 or lifting device 150 (e.g., a Human-Machine Interface, HMI, of the crane arm 160or lifting device 150), a mobile device (e.g., a mobile phone, a laptop-computer or a tabletcomputer) of the operator of the crane arm 160 or lifting device 150, or a remote server.

[0051] The device control circuitry 155 may be further configured to control the opening degree of the valve 175 based on the user input data 107 to cause slewing motion of the crane arm 160 according to the user input. The device control circuitry 155 is configured to initially set the opening degree of the valve 175 to the determined initial opening degree for the valve 175 to initiate the slewing motion of the crane arm 160. In other words, once the user input is received, the device control circuitry 155 may adjust the opening degree of the valve 175 based on the user input (e.g., based on the based on the magnitude and direction indicated by the user input) to regulate the flow of hydraulic fluid to the slewing drive 180. By setting the opening degree of the valve 175 to the determined initial opening degree, the device control circuitry 155 ensures that the slewing motion of the crane arm 160 starts smoothly and with sufficient hydraulic compensation for potential leakage or gravitational effects. In particular, sudden movements or jerks at the start of the slewing motion may be avoided.

[0052] In the following, the determination of the initial opening degree for the valve 175 will be described in greater detail.

[0053] The crane arm 160's inclination affects how gravity interacts with the load and the crane arm 160. If the crane arm 160 is slewing downhill, less hydraulic force is required, whereas slewing uphill requires additional force to overcome gravitational resistance. Knowing the lateral inclination of the crane arm 160 allows to determine the initial opening degree for the valve 175 such that unintended movement, in particular jerking, or stalling may be prevented. Accordingly, for determining the initial opening degree for the valve 175, the processing circuitry 110 may configured to determine the lateral inclination of the crane arm 160. The lateral inclination of the crane arm 160 refers to the tilt of the crane arm 160 relative to the horizontal plane, measured in a direction perpendicular to the longitudinal axis of extension of the crane arm 160. It represents the angular deviation of the crane arm 160 from a perfectly level position in the side-to-side (left-right) direction with respect to the lifting device 150's operational orientation.

[0054] The first input data 101 indicate an inclination measured at the lifting device 150. As described above, the inclination sensor 190 may be arranged at various parts of the lifting device 150. Accordingly, the determination of the lateral inclination of the crane arm 160 may vary based on the type of measured inclination indicated by the first input data 101. For example, if the first input data 101 indicate the measured inclination of the crane arm 160about two orthogonal axes (i.e., the inclination sensor 190 is arranged at the crane arm 160 measuring, e.g., forward-backward and side-to-side), the processing circuitry 110 may be configured to determine the lateral inclination of the crane arm 160 based on the measured inclination of the crane arm 160. Since the inclination sensor 190 is directly mounted on the crane arm 160, it provides real-time and precise measurements of the crane arm 160's inclination, eliminating the need for complex calculations. The processing circuitry 110 may directly use the measured inclination to determine the lateral tilt. No further measurement data is needed to determine the lateral inclination of the crane arm 160.

[0055] On the other hand, if the first input data 101 indicate the measured inclination of the device base 151 about two orthogonal axes (i.e., the inclination sensor 190 is arranged at the device base 151 measuring, e.g., forward-backward and side-to-side), the processing circuitry 110 may be further configured to receive third input data 103 indicating a current slewing angle of the crane arm 160. The slewing angle refers to the angular position of the crane arm 160 relative a fixed reference point (predefined zero position) on the crane base 151, measured around the vertical slewing axis z of the lifting equipment 150. The slewing angle may be defined in a clockwise or counterclockwise slewing direction. For example, the lifting device 150 may comprise a slewing sensor 196 configured to measure the current slewing angle of the crane arm 160, and generate the third input data 103 based thereon. The slewing sensor 196 may, e.g., be integrated into the slewing drive 180. In these examples, the processing circuitry 110 may configured to determine the lateral inclination of the crane arm 160 based on the measured inclination of the device base 151 and the current slewing angle of the crane arm 160. As the crane arm 160 rotates relative to the device base 151, the tilt detected at the base device base 151 does not directly reflect the crane arm 160's lateral inclination. The processing circuitry 110 uses the current slewing angle to calculate how the crane arm 160’s position affects its inclination relative to the environment. For example, the processing circuitry 110 may perform one or more trigonometric transformations to project the measured inclination of the base device 151 onto the crane arm 160’s current position using the current slewing angle. The device base 151 is less affected by dynamic forces such as arm vibrations, leading to more stable readings of the inclination. In some example, the more stable readings of the inclination may be preferred over the simpler calculation for the sensor placement directly at the crane arm 160.

[0056] As described above, slewing uphill and downhill requires different hydraulic force due to gravity. This effect may be considered by the processing circuitry 110 for determining the initial opening degree for the valve 175. The processing circuitry 110 may, e.g., be configured to determine, based on the determined lateral inclination of the crane arm 160, whichone of a clockwise slewing motion or a counterclockwise slewing motion of the crane arm 160 corresponds to slewing the crane arm 160 in a direction aligned with the lateral inclination of the crane arm 160. Furthermore, processing circuitry 110 may be configured to determine, based on the determined lateral inclination of the crane arm 160, which one of the clockwise slewing motion or the counterclockwise slewing motion of the crane arm 160 corresponds to slewing the crane arm 160 in a direction against the lateral inclination of the crane arm 160.

[0057] A slewing motion of the crane arm 160 is in the direction aligned with the lateral inclination of the crane arm when the movement of the crane arm 160 occurs in the same direction as the gravitational pull resulting from the tilt of the crane arm 160. For example, if the crane arm 160 is tilted to the right, slewing the crane 160 clockwise (rightward) would be aligned with the lateral inclination of the crane arm 160. Analogously, if the crane arm 160 is tilted to the left, slewing the crane 160 counterclockwise (leftward) would be aligned with the lateral inclination of the crane arm 160. In other words, a slewing motion of the crane arm 160 in the direction aligned with the lateral inclination of the crane arm 160 refers to downhill slewing. On the other hand, a slewing motion of the crane arm 160 is in the direction against the lateral inclination of the crane arm 160 when the movement of the crane arm 160 occurs in the opposite direction to the gravitational pull resulting from the tilt of the crane arm 160. For example, if the crane arm 160 is tilted to the right, slewing the crane 160 counterclockwise (leftward) would be against the lateral inclination of the crane arm 160. Analogously, if the crane arm 160 is tilted to the left, slewing the crane 160 clockwise (rightward) would be against the lateral inclination of the crane arm 160. In other words, a slewing motion of the crane arm 160 in the direction against the lateral inclination of the crane arm 160 refers to uphill slewing.

[0058] Accordingly, the processing circuitry 110 may use conditional logic to evaluate the lateral inclination of the crane arm 160 and the slewing direction. For example, the determined lateral inclination of the crane arm 160 may be compared to a predefined value such as zero. If the lateral inclination of the crane arm 160 is greater than zero, the crane arm 160 is tilted to the right. Accordingly, slewing the crane 160 clockwise would be aligned with the lateral inclination of the crane arm 160, and slewing the crane 160 counterclockwise would against the lateral inclination of the crane arm 160. If the lateral inclination of the crane arm 160 is smaller than zero, the crane arm 160 is tilted to the left. Accordingly, slewing the crane 160 counterclockwise would be aligned with the lateral inclination of the crane arm 160, and slewing the crane 160 clockwise would against the lateral inclination of the crane arm 160.When initiating slewing aligned with inclination, the hydraulic force may be reduced (by reducing the initial opening degree for the valve 175), conserving energy and reducing wear on the components of the slewing drive 180. By identifying the slewing direction relative to inclination, the apparatus 100 can foresee additional hydraulic power (by increasing the initial opening degree for the valve 175) when initiating moving against gravity to counteract potential hydraulic leakage and prevent rollback or unintended movement (such as jerking). The apparatus 100 ensures that the crane arm 160 starts moving gradually and predictably based on its orientation and intended slewing direction.

[0059] According to examples, the processing circuitry 110 may be configured to set the initial opening degree for the valve 175 to a predefined value for the one of the clockwise slewing motion and the counterclockwise slewing motion of the crane arm 160 that is determined to correspond to slewing the crane arm 160 in the direction aligned with the lateral inclination of the crane arm 160. In other words, if the slewing is downhill, the processing circuitry 110 may be configured to limit the initial opening degree for the valve 175 to the predefined value. The predefined value is preset threshold for the initial opening degree for the valve 175 that is applied for slewing the crane arm 160 in the direction aligned with its lateral inclination to prevent excessive acceleration and improve control. The predefined value helps compensate for gravitational assistance, which otherwise could lead to uncontrolled movement. Setting the valve to a predefined value ensures that movement starts smoothly and progressively. For example, the predefined value may be 0 % (of the full capacity) such that the valve 175 remains closed, preventing any hydraulic fluid from flowing to the slewing drive 180. In other examples, the predefined value may be more than 0 % but less than 5 % (of the full capacity) such that the valve is slightly opened to allow controlled flow of hydraulic fluid to the slewing drive 180, ensuring just enough flow is provided for smooth movement without unnecessary acceleration.

[0060] On the other hand, the processing circuitry 110 may be configured to determine the initial opening degree for the valve 175 for the one of the clockwise slewing motion and the counterclockwise slewing motion of the crane arm 160 that is determined to correspond to slewing the crane arm in the direction against the lateral inclination of the crane arm 160 based on the lateral inclination of the crane arm 160 and the measured pressure in the hydraulic cylinder of the crane arm 160. In other words, if the slewing is uphill, the processing circuitry 110 may be configured to calculate the initial opening degree for the valve 175 based on lateral inclination of the crane arm 160 and the measured pressure in the hydraulic cylinder of the crane arm 160 (e.g., the pressure in the hydraulic cylinder 165). For example, theprocessing circuitry 110 may be configured to calculate (determine) how much force is required to move the crane arm 160 against the lateral inclination of the crane arm 160, factoring in the lateral inclination of the crane arm 160 and the current load handled by the crane arm 160. Furthermore, the processing circuitry may be configured to calculate (determine) the additional force required to overcome gravitational and load resistance by considering the effect of tilt on the fluid leakage within the hydraulic motor 181 of the slewing drive 180 and the fluid pressure required to initiate movement against the lateral inclination of the crane arm 160 without lag or jerking. Based thereon, the processing circuitry 100 may determine the initial opening degree for the valve 175 that provides enough hydraulic fluid to start the slewing motion smoothly and consistently. Accordingly, jerky or abrupt movements as well as delays or hesitation may be prevented when moving uphill.

[0061] A specific example of how to determine the initial opening degree for the valve 175 based on the lateral inclination of the crane arm 160 and the measured pressure in the hydraulic cylinder of the crane arm 160 will be given in the following.

[0062] In this example, the processing circuitry 110 is configured to further receive 1) fourth input data 104 indicating a maximum allowed pressure in the hydraulic cylinder of the crane arm 160 (e.g., the hydraulic cylinder 165) and 2) fifth input data 105 indicating a reference lateral inclination of the crane arm 160. The maximum allowed pressure in the hydraulic cylinder of the crane arm 160 is the upper operational limit for the pressure in the hydraulic cylinder. The reference lateral inclination of the crane arm 160 is a reference inclination level, against which the current lateral inclination of the crane arm 160 is compared.

[0063] For determining the initial opening degree for the valve 175 for the one of the clockwise slewing motion and the counterclockwise slewing motion of the crane arm 160 that is determined to correspond to slewing the crane arm 160 in the direction against the lateral inclination of the crane arm 160, the processing circuitry 110 is in this example further configured to determine a first scaling factor Si based on the measured pressure pmeasand the maximum allowed pressure pmaxin the hydraulic cylinder of the crane arm 160:

[0064] 1 f (.Pmeas’ Pmax) (”0

[0065] The first scaling factor Si is a load-based scaling factor. The first scaling factor Si accounts for the crane arm 160's load conditions by using the measured hydraulic pressure pmeasto assess the capacity utilization of the crane arm 160. Capacity utilization refers to how much of the crane arm 160 's maximum load capacity is currently being used, which directly af-fects the hydraulic force required for slewing against the lateral inclination. For example, the first scaling factor Si may be calculated based on the ratio of the measured pressure pmeasto the maximum allowed pressure pmaxin the hydraulic cylinder of the crane arm 160. In other words, the first scaling factor Si may change linearly with the measured pressure Pmeas in the hydraulic cylinder of the crane arm 160.

[0066] In this example, the processing circuitry 110 is additionally configured to determine a second scaling factor S2based on the determined lateral inclination idetof the crane arm 160 and the reference lateral inclination irefof the crane arm 160:

[0067]

[0068] Various mathematical functions may be used for the determination of the second scaling factor S2. For example, the second scaling factor S2may be calculated based on the ratio of the sine of the determined lateral inclination idetto the sine of the reference lateral inclination iref, ensuring a smooth and proportional adjustment based on the inclination of the crane arm. In other words, the second scaling factor S2may change with the sine of determined lateral inclination idet. The second scaling factor S2may be any value greater zero.

[0069] The processing circuitry 110 is in this example further configured to determine the initial opening degree Dinitfor the valve 175 by scaling a default opening degree DdefaiMfor the valve 175 based on first and second scaling factors Si and S2.

[0070] init Dde aun ‘ S±■ S2(3)

[0071] This ensures that both load and inclination effects are accurately factored into the hydraulic control. According to examples of the present disclosure, the initial opening degree Dinitfor the valve 175 may change linearly with the capacity utilization of the crane arm 160 and with a sine function with the lateral inclination of the crane arm 160.

[0072] The default opening degree for the valve 175 refers to a predefined baseline value of the valve opening that serves as an initial reference for regulating the supply of hydraulic fluid to the slewing drive 180. It acts as an initial reference point before further adjustments based on load and inclination. The default opening degree may be configured at a specific crane inclination and crane capacity utilization, ensuring the correct amount of hydraulic fluid is supplied to the slewing drive 180 to initiate smooth movement. This value may be set basedon one or more of a model of the lifting device 150, system design parameters, operational requirements, or user-defined preferences and may be adjusted to optimize performance under different load and inclination conditions. For example, the processing circuitry 110 may be configured to receive user input data 106 indicating the default opening degree for the valve 175. This allows operators, service technicians, or system integrators to manually adjust the default opening degree to match specific operational needs or preferences. For example, the default opening degree for the valve 175 may be configured during installation or routine maintenance to align with the lifting device 150's performance expectations. The processing circuitry 110 may, e.g., receive the user input data from a remote control for controlling the lifting device 150, an element or circuitry of the crane arm 160 or lifting device 150 (e.g., an HMI of the crane arm 160 or lifting device 150), a mobile device (e.g., a mobile phone, a laptop-computer or a tablet-computer) of the operator of the crane arm 160 or lifting device 150, or a remote server.

[0073] In some examples, the processing circuitry 110 may be configured to limit the determined first scaling factor Si to one (1.0) if it exceeds one (1.0). In other words, the capacity utilization of the crane arm 160, which is represented by the first scaling factor Si, may be limited to be within 0 % and 100 %. If the measured pressure pmeasexceeds the maximum allowed pressure pmax(e.g., due to sensor inaccuracies, overload conditions, or transient spikes), the first scaling factor Si would naturally exceed one. The processing circuitry 110 may cap the value at one, ensuring that the initial opening degree for the valve 175 does not exceed the design capacity of the hydraulic system 170. This may ensure that the hydraulic system 170 does not attempt to provide more force than it is designed for. By avoiding overcompensation, stability and consistency in the hydraulic control may be ensured.

[0074] Prior to determining the second scaling factor S2, the processing circuitry 110 may in some examples be configured to limit the determined lateral inclination of the crane arm 160 to a predefined value if the determined lateral inclination of the crane arm 160 exceeds the predefined value. The predefined value refers to a preset threshold for the lateral inclination of the crane arm 160, which serves as an upper limit to ensure safe and stable operation of the lifting equipment 150. If the determined lateral inclination of the crane arm 160 exceeds this threshold, the processing circuitry 110 may cap the value at the predefined limit before further processing to prevent excessive corrections or unsafe movements. For example, the predefined value may be 4 °, 5 °, 6 °, 7 °, 8 ° or 9 °.

[0075] In cases of small lateral inclinations and low capacity utilization of the crane arm 160, the inherent friction in the slewing drive 180 may be sufficient to prevent unintended downwardmovement when the crane arm 160 starts to slew against its lateral inclination. When setting the initial opening degree for the valve 175 to too high values, the crane arm 160 could experience a jerk when starting slewing against gravity. For preventing such jerky movements, the processing circuitry 110 may be further configured to reduce the initial opening degree for the valve 175 for the one of the clockwise slewing motion and the counterclockwise slewing motion of the crane arm 175 that is determined to correspond to slewing the crane arm 175 in the direction against the lateral inclination of the crane arm 175 by a predefined amount. The reduced initial opening degree is limited to zero if it would otherwise fall below zero. In other words, if the initial opening degree for the valve 175 is small and slewing is uphill, a predefined reduction offset may be applied to reduce the value. If the reduced value falls below 0 %, it is limited to 0 %, ensuring that no hydraulic fluid is supplied to the slewing drive 180. This offset allows to leverage the inherent friction in the slewing drive 180, which may naturally hold the crane arm 160 in position under low-inclination and low-load conditions. For example, the predefined amount may be 1 °, 2 ° or 3 °.

[0076] The predefined amount may be parameterizable. For example, the processing circuitry 110 may be configured to receive further user input data indicating the predefined amount. This allows operators, service technicians, or system integrators to manually adjust the predefined amount to match specific operational needs or preferences. For example, the predefined amount may be configured during installation or routine maintenance to align with the lifting device 150's performance expectations. The processing circuitry 110 may, e.g., receive the further user input data from a remote control for controlling the lifting device 150, an element or circuitry of the crane arm 160 or lifting device 150 (e.g., an HMI of the crane arm 160 or lifting device 150), a mobile device (e.g., a mobile phone, a laptop-computer or a tablet-computer) of the operator of the crane arm 160 or lifting device 150, or a remote server.

[0077] Alternatively, the processing circuitry 110 may be further configured to set the initial opening degree for the valve 175 to a predefined value for the one of the clockwise slewing motion and the counterclockwise slewing motion of the crane arm 160 that is determined to correspond to slewing the crane arm 160 in the direction against the lateral inclination of the crane arm 160 if the determined initial opening degree for the valve 175 is below a threshold value. In other words, if the initial opening degree for the valve 175 is small and slewing is uphill, the initial opening degree for the valve 175 is capped (limited) to the predefined value. For example, the threshold value may be 1 °, 2 or 3 °. The predefined value may, e.g., be 0 ° or 1 °. One or both of the threshold value and the predefined value may be parameterizable to allow operators, service technicians, or system integrators to manuallyadjust one or both of the threshold value and the predefined value to match specific operational needs or preferences. For example, the processing circuitry 110 may be configured to receive further user input data indicating one or both of the threshold value and the predefined value. The processing circuitry 110 may, e.g., receive the further user input data from a remote control for controlling the lifting device 150, an element or circuitry of the crane arm 160 or lifting device 150 (e.g., an HMI of the crane arm 160 or lifting device 150), a mobile device (e.g., a mobile phone, a laptop-computer or a tablet-computer) of the operator of the crane arm 160 or lifting device 150, or a remote server.

[0078] Fig. 2 illustrates an exemplary timing diagram 200 showing courses of the initial opening degrees for the valve 175 over the lateral inclination of the crane arm 160 for clockwise and counterclockwise slewing motion of the crane arm 160. The abscissa of the timing diagram 200 represents time in arbitrary units, while the ordinate indicates the corresponding values of the depicted parameters in degrees.

[0079] Curve 210 represents the lateral inclination of the crane arm 160 over time. Initially, the crane arm tilts in one direction (e.g., to the left), reaching a peak inclination, and subsequently tilts in the opposite direction (e.g., to the right) before returning to its original position.

[0080] Curves 220 and 230 respectively illustrate the determined initial opening degree for the valve 175 for clockwise and counterclockwise slewing of the crane arm 160. As can be seen from curve 220, the initial opening degree for the valve 175 is adjusted in accordance with the lateral inclination of the crane arm 160 while the clockwise slewing is against the lateral inclination of the crane arm 160, and the initial opening degree for the valve 175 is set to the predefined value 0 ° while the clockwise slewing is aligned with the lateral inclination of the crane arm 160. Curve 230 analogously shows the determination of the initial opening degree for the valve 175 for the counterclockwise slewing of the crane arm 160. The curves 220 and 230 demonstrate how the apparatus 100 dynamically adjusts the initial opening degree for the valve 175 in response to the lateral inclination of the crane arm 160.

[0081] The plateaus 225 and 235 observed in the curves 220 and 230 are due to the limitation applied to the lateral inclination of the crane arm 160, which is capped at a predefined value (e.g., 5°) during the determination of the initial opening degrees for the valve 175 - as described above. This limitation is implemented to ensure that the slewing control remains within specified operational boundaries, thereby preventing excessive hydraulic adjustments that could impact crane stability.Near the zero crossing of the curve 210 (indicating that the crane arm 160 passes through its neutral position), both curves 220 and 230 exhibit zero values. This behavior results from the reduction of the determined initial opening degree for the valve 175 by a predefined amount (e.g., 2 °) as described above. The predefined reduction is applied to leverage the inherent friction within the slewing drive 180, preventing unintended, particularly jerky movements..

[0082] Fig. 2 highlights how the apparatus 100 effectively adapts the initial opening degrees for the valve 175 to achieve smooth and controlled slewing initiation, dynamically responding to changes in lateral inclination while minimizing abrupt movements.

[0083] Fig. 3 illustrates an exemplary data flow 300 in the processing circuitry 110 for determining the initial opening degree for the valve 175. The first and third input data 101 and 103 indicating the measured inclination of the device base 151 about two orthogonal axes and the current slewing angle of the crane arm 160 are received.

[0084] Block 310 visualizes the determination of the lateral inclination of the crane arm 160 based on the measured inclination of the device base 151 and the current slewing angle of the crane arm 160, as well as the determination of the second scaling factor 311 based on the determined lateral inclination of the crane arm 160 and a reference lateral inclination. The details are described above.

[0085] Block 320 visualizes the determination of the first scaling factor 321 based on the second and fourth input data 102 and 104 indicating the measured pressure and the maximum allowed pressure in a hydraulic cylinder of the crane arm 160 (e.g. the hydraulic cylinder 165). As indicated by block 340, the initial opening degree for the valve 175 is then determined by scaling a default opening degree 301 for the valve 175 based on the first and second scaling factors 311 and 321.

[0086] Block 330 visualizes the determination of which one of a clockwise slewing motion or a counterclockwise slewing motion of the crane arm 160 corresponds to slewing the crane arm 160 in the direction aligned with the lateral inclination of the crane arm 160, and which corresponds to slewing the crane arm 160 in the direction against the lateral inclination of the crane arm 160. As described above, the determined lateral inclination of the crane arm 160 is compared to a predefined value such as zero. If the lateral inclination of the crane arm 160 is larger than the predefined value, it is determined that the clockwise slewing mo-tion is aligned with the lateral inclination of the crane arm 160. If the lateral inclination of the crane arm 160 is less than the predefined value, it is determined that the counterclockwise slewing motion is aligned with the lateral inclination of the crane arm 160.

[0087] If it is determined that the clockwise slewing motion is aligned with the lateral inclination of the crane arm 160, block 350 is activated and subtracts an offset value 302 from the determined initial opening degree for the valve 175. Analogously, if it is determined that the counterclockwise slewing motion is aligned with the lateral inclination of the crane arm 160, block 360 is activated and subtracts the offset value 302 from the determined initial opening degree for the valve 175.

[0088] The blocks 350 and 360 further receive a predefined value 303 for the one of the clockwise slewing motion and the counterclockwise slewing motion of the crane arm 160 that is determined to correspond to slewing the crane arm 160 in the direction aligned with the lateral inclination of the crane arm 160. The predefined value 303 may, e.g., be zero.

[0089] If it is determined that the clockwise slewing motion is aligned with the lateral inclination of the crane arm 160, the updated initial opening degree for the valve 175 is forwarded by the block 350 to block 370 and forms the final initial opening degree for the valve 175 for the counterclockwise slewing motion. The predefined value 303 is forwarded by the block 350 to block 380 and forms the final initial opening degree for the valve 175 for the clockwise slewing motion (e.g. zero).

[0090] Analogously, if it is determined that the counterclockwise slewing motion is aligned with the lateral inclination of the crane arm 160, the updated initial opening degree for the valve 175 is forwarded by the block 360 to block 380 and forms the final initial opening degree for the valve 175 for the clockwise slewing motion. The predefined value 303 is forwarded by the block 360 to block 370 and forms the final initial opening degree for the valve 175 for the counterclockwise slewing motion (e.g. zero).

[0091] As described above, the lifting device 150 may be mounted to a vehicle. Fig. 4 illustrates a truck as an exemplary vehicle 400 having mounted thereon the lifting device 150 described above. The initial opening degree of the valve 175 for initiating a slewing motion of the crane arm 160 is determined by the apparatus 100 as described above.

[0092] Compared to conventional vehicles, the vehicle 400 may effectively compensate for hydraulic leakage while simultaneously avoiding jerky motion during slewing initiation. The ability toperform various task such as loading and unloading heavy materials, moving construction components, or lifting device without jerky motion during slewing initiation makes the vehicle 400 highly valuable in various industries.

[0093] Fig. 4 focuses on a truck as an exemplary vehicle. However, as indicated above, the present disclosure is not limited to trucks. The vehicle 400 may be any land vehicle (e.g., wheeled, tracked or railed, for example, a truck, a lorry or a crawler) or watercraft (e.g., a ship, a boat or a barge).

[0094] For further highlighting the slewing initiation described above, Fig. 5 illustrates a flowchart of a method 500 for determining an initial opening degree for a valve regulating the supply of hydraulic fluid to a slewing drive of a lifting device to initiate a slewing motion of a crane arm of the lifting device. The method 500 comprises receiving 502 first input data indicating an inclination measured at the lifting device. Additionally, the method 500 comprises receiving 504 second input data indicating a measured pressure in a cylinder of the crane arm. The method 500 further comprises determining 506 the initial opening degree for the valve based on the first and second input data.

[0095] Analogously to what is described above, the method 500 may allow to effectively compensate for hydraulic leakage while simultaneously avoiding jerky motion during slewing initiation.

[0096] More details and aspects of the method 500 are explained in connection with the proposed technique or one or more examples described above (e.g., Fig. 1 to Fig. 4). The method 500 may comprise one or more additional optional features corresponding to one or more aspects of the proposed technique or one or more examples described above.

[0097] The examples described herein may be summarized as follows:

[0098] An example (e.g., example 1) relates to an apparatus for determining an initial opening degree for a valve regulating the supply of hydraulic fluid to a slewing drive of a lifting device to initiate a slewing motion of a crane arm of the lifting device. The apparatus comprises processing circuitry configured to receive first input data indicating an inclination measured at the lifting device. Additionally, the apparatus is configured to receive second input data indicating a measured pressure in a hydraulic cylinder of the crane arm. The apparatus is additionally configured to determine the initial opening degree for the valve based on the first and second input data.Another example (e.g., example 2) relates to a previous example (e.g., example 1) or to any other example, wherein the first input data indicate the measured inclination of the crane arm about two orthogonal axes, and wherein, for determining the initial opening degree for the valve, the processing circuitry is configured to determine a lateral inclination of the crane arm based on the measured inclination of the crane arm.

[0099] Another example (e.g., example 3) relates to a previous example (e.g., example 1) or to any other example, wherein the first input data indicate the measured inclination of a device base of the lifting device about two orthogonal axes, wherein the processing circuitry is further configured to receive third input data indicating a current slewing angle of the crane arm, and wherein, for determining the initial opening degree for the valve, the processing circuitry is configured to determine a lateral inclination of the crane arm based on the measured inclination of the device base and the current slewing angle of the crane arm.

[0100] Another example (e.g., example 4) relates to a previous example (e.g., one of the examples 2 or 3) or to any other example, wherein, for determining the initial opening degree for the valve, the processing circuitry is configured to determine, based on the lateral inclination of the crane arm, which one of a clockwise slewing motion or a counterclockwise slewing motion of the crane arm corresponds to slewing the crane arm in a direction aligned with the lateral inclination of the crane arm, and which corresponds to slewing the crane arm in a direction against the lateral inclination of the crane arm.

[0101] Another example (e.g., example 5) relates to a previous example (e.g., example 4) or to any other example, wherein the processing circuitry is further configured to set the initial opening degree for the valve to a predefined value for the one of the clockwise slewing motion and the counterclockwise slewing motion of the crane arm that is determined to correspond to slewing the crane arm in the direction aligned with the lateral inclination of the crane arm.

[0102] Another example (e.g., example 6) relates to a previous example (e.g., one of the examples 4 or 5) or to any other example, wherein the processing circuitry is further configured to determine the initial opening degree for the valve for the one of the clockwise slewing motion and the counterclockwise slewing motion of the crane arm that is determined to correspond to slewing the crane arm in the direction against the lateral inclination of the crane arm based on the lateral inclination of the crane arm and the measured pressure in the hydraulic cylinder of the crane arm.Another example (e.g., example 7) relates to a previous example (e.g., example 6) or to any other example, wherein the processing circuitry is further configured to receive fourth input data indicating a maximum allowed pressure in the hydraulic cylinder of the crane arm and fifth input data indicating a reference lateral inclination of the crane arm, and wherein, for determining the initial opening degree for the valve for the one of the clockwise slewing motion and the counterclockwise slewing motion of the crane arm that is determined to correspond to slewing the crane arm in the direction against the lateral inclination of the crane arm, the processing circuitry is configured to: determine a first scaling factor based on the measured pressure and the maximum allowed pressure in the hydraulic cylinder of the crane arm; determine a second scaling factor based on the lateral inclination of the crane arm and the reference lateral inclination of the crane arm; and determine the initial opening degree for the valve by scaling a default opening degree for the valve based on the first and second scaling factors.

[0103] Another example (e.g., example 8) relates to a previous example (e.g., example 7) or to any other example, wherein the processing circuitry is further configured to limit the determined first scaling factor to one if it exceeds one.

[0104] Another example (e.g., example 9) relates to a previous example (e.g., one of the examples 7 or 8) or to any other example, wherein, prior to determining the second scaling factor, the processing circuitry is further configured to limit the lateral inclination of the crane arm to a predefined value if the lateral inclination of the crane arm exceeds the predefined value.

[0105] Another example (e.g., example 10) relates to a previous example (e.g., one of the examples 7 to 9) or to any other example, wherein the processing circuitry is configured to receive user input data indicating the default opening degree for the valve.

[0106] Another example (e.g., example 11) relates to a previous example (e.g., one of the examples 6 to 10) or to any other example, wherein the processing circuitry is further configured to: set the initial opening degree for the valve to a predefined value for the one of the clockwise slewing motion and the counterclockwise slewing motion of the crane arm that is determined to correspond to slewing the crane arm in the direction against the lateral inclination of the crane arm if the determined initial opening degree for the valve is below a threshold value; or reduce the initial opening degree for the valve for the one of the clockwise slewing motion and the counterclockwise slewing motion of the crane arm that is determined to correspond to slewing the crane arm in the direction against the lateral inclina-tion of the crane arm by a predefined amount, wherein the reduced initial opening degree is limited to zero if it would otherwise fall below zero.

[0107] Another example (e.g., example 12) relates to a previous example (e.g., one of the examples 1 to 11) or to any other example, wherein the processing circuitry is configured to continuously determine the initial opening degree for the valve over time.

[0108] An example (e.g., example 13) relates to a lifting device. The lifting device comprises a crane arm and a hydraulically driven slewing drive for slewing the crane arm. Additionally, the lifting device comprises a hydraulic system configured to generate flow of hydraulic fluid. The hydraulic system comprises a valve for regulating the supply of hydraulic fluid to the slewing drive. Further, the lifting device comprise an apparatus for determining an initial opening degree for the valve to initiate a slewing motion of the crane arm according to previous example (e.g., one of the examples 1 to 12) or to any other example.

[0109] Another example (e.g., example 14) relates to a previous example (e.g., example 13) or to any other example, further comprising: an inclination sensor configured to generate the first input data; and a pressure sensor configured to generate the second input data.

[0110] Another example (e.g., example 15) relates to a previous example (e.g., one of the examples 13 or 14) or to any other example, further comprising control circuitry configured to: receive user input data indicating a user input for slewing the crane arm; and control the opening degree of the valve based on the user input data to cause slewing motion of the crane arm according to the user input, wherein the control circuitry is configured to initially set the opening degree of the valve to the determined initial opening degree for the valve to initiate the slewing motion of the crane arm.

[0111] Another example (e.g., example 16) relates to a previous example (e.g., one of the examples 13 to 15) or to any other example, wherein the lifting device is a knuckle boom crane.

[0112] An example (e.g., example 17) relates to a vehicle having mounted thereon a lifting device according to a previous example (e.g., one of the examples 13 to 16) or to any other example.

[0113] An example (e.g., example 18) relates to a method for determining an initial opening degree for a valve regulating the supply of hydraulic fluid to a slewing drive of a lifting device to initiate a slewing motion of a crane arm of the lifting device. The method comprises receivingfirst input data indicating an inclination measured at the lifting device. Additionally, the method comprises receiving second input data indicating a measured pressure in a hydraulic cylinder of the crane arm. The method further comprises determining the initial opening degree for the valve based on the first and second input data.

[0114] Another example (e.g., example 19) relates to a non-transitory machine-readable medium having stored thereon a program having a program code for performing the method according to a previous example (e.g., example 18) or to any other example, when the program is executed on a processor or a programmable hardware.

[0115] Another example (e.g., example 20) relates to a program having a program code for performing the method according to a previous example (e.g., example 18) or to any other example, when the program is executed on a processor or a programmable hardware.

[0116] The aspects and features described in relation to a particular one of the previous examples may also be combined with one or more of the further examples to replace an identical or similar feature of that further example or to additionally introduce the features into the further example.

[0117] Examples may further be or relate to a (computer) program including a program code to execute one or more of the above methods when the program is executed on a computer, processor or other programmable hardware component. Thus, steps, operations or processes of different ones of the methods described above may also be executed by programmed computers, processors or other programmable hardware components. Examples may also cover program storage devices, such as digital data storage media, which are machine-, processor- or computer-readable and encode and / or contain machineexecutable, processor-executable or computer-executable programs and instructions. Program storage devices may include or be digital storage devices, magnetic storage media such as magnetic disks and magnetic tapes, hard disk drives, or optically readable digital data storage media, for example. Other examples may also include computers, processors, control units, (field) programmable logic arrays ((F)PLAs), (field) programmable gate arrays ((F)PGAs), graphics processor units (GPU), ASICs, integrated circuits (ICs) or SoC programmed to execute the steps of the methods described above.

[0118] It is further understood that the disclosure of several steps, processes, operations or functions disclosed in the description or claims shall not be construed to imply that these operations are necessarily dependent on the order described, unless explicitly stated in the indi-vidual case or necessary for technical reasons. Therefore, the previous description does not limit the execution of several steps or functions to a certain order. Furthermore, in further examples, a single step, function, process or operation may include and / or be broken up into several sub-steps, -functions, -processes or -operations.

[0119] If some aspects have been described in relation to a device or system, these aspects should also be understood as a description of the corresponding method. For example, a block, device or functional aspect of the device or system may correspond to a feature, such as a method step, of the corresponding method. Accordingly, aspects described in relation to a method shall also be understood as a description of a corresponding block, a corresponding element, a property or a functional feature of a corresponding device or a corresponding system.

[0120] The following claims are hereby incorporated in the detailed description, wherein each claim may stand on its own as a separate example. It should also be noted that although in the claims a dependent claim refers to a particular combination with one or more other claims, other examples may also include a combination of the dependent claim with the subject matter of any other dependent or independent claim. Such combinations are hereby explicitly proposed, unless it is stated in the individual case that a particular combination is not intended. Furthermore, features of a claim should also be included for any other independent claim, even if that claim is not directly defined as dependent on that other independent claim.

Claims

ClaimsWhat is claimed is:

1. An apparatus (100) for determining an initial opening degree for a valve (175) regulating the supply of hydraulic fluid to a slewing drive (180) of a lifting device (150) to initiate a slewing motion of a crane arm (160) of the lifting device (150), the apparatus (100) comprising processing circuitry (110) configured to:receive first input data (101) indicating an inclination measured at the lifting device (150); receive second input data (102) indicating a measured pressure in a hydraulic cylinder (165) of the crane arm (160); anddetermine the initial opening degree for the valve (175) based on the first and second input data (101, 102).

2. The apparatus (100) of claim 1, wherein the first input data (101) indicate the measured inclination of the crane arm (160) about two orthogonal axes, and wherein, for determining the initial opening degree for the valve (175), the processing circuitry (110) is configured to determine a lateral inclination of the crane arm (160) based on the measured inclination of the crane arm (160).

3. The apparatus (100) of claim 1, wherein the first input data (101) indicate the measured inclination of a device base of the lifting device (150) about two orthogonal axes, wherein the processing circuitry (110) is further configured to receive third input data (103) indicating a current slewing angle of the crane arm (160), and wherein, for determining the initial opening degree for the valve (175), the processing circuitry (110) is configured to determine a lateral inclination of the crane arm (160) based on the measured inclination of the device base and the current slewing angle of the crane arm (160).

4. The apparatus (100) of claim 2 or claim 3, wherein, for determining the initial opening degree for the valve (175), the processing circuitry (110) is configured to determine, based on the lateral inclination of the crane arm (160), which one of a clockwise slewing motion or a counterclockwise slewing motion of the crane arm (160) corresponds to slewing the crane arm (160) in a direction aligned with the lateral inclination of the crane arm (160), and which corresponds to slewing the crane arm (160) in a direction against the lateral inclination of the crane arm (160).

5. The apparatus (100) of claim 4, wherein the processing circuitry (110) is further configured to set the initial opening degree for the valve (175) to a predefined value for the oneof the clockwise slewing motion and the counterclockwise slewing motion of the crane arm (160) that is determined to correspond to slewing the crane arm (160) in the direction aligned with the lateral inclination of the crane arm (160).

6. The apparatus (100) of claim 4 or claim 5, wherein the processing circuitry (110) is further configured to determine the initial opening degree for the valve (175) for the one of the clockwise slewing motion and the counterclockwise slewing motion of the crane arm (160) that is determined to correspond to slewing the crane arm (160) in the direction against the lateral inclination of the crane arm (160) based on the lateral inclination of the crane arm (160) and the measured pressure in the hydraulic cylinder (165) of the crane arm (160).

7. The apparatus (100) of claim 6, wherein the processing circuitry (110) is further configured to receive fourth input data (104) indicating a maximum allowed pressure in the hydraulic cylinder (165) of the crane arm (160) and fifth input data (105) indicating a reference lateral inclination of the crane arm (160), and wherein, for determining the initial opening degree for the valve (175) for the one of the clockwise slewing motion and the counterclockwise slewing motion of the crane arm (160) that is determined to correspond to slewing the crane arm (160) in the direction against the lateral inclination of the crane arm (160), the processing circuitry (110) is configured to:determine a first scaling factor based on the measured pressure and the maximum allowed pressure in the hydraulic cylinder (165) of the crane arm (160);determine a second scaling factor based on the lateral inclination of the crane arm (160) and the reference lateral inclination of the crane arm (160); anddetermine the initial opening degree for the valve (175) by scaling a default opening degree for the valve (175) based on the first and second scaling factors.

8. The apparatus (100) of claim 7, wherein the processing circuitry (110) is further configured to limit the determined first scaling factor to one if it exceeds one.

9. The apparatus (100) of claim 7 or claim 8, wherein, prior to determining the second scaling factor, the processing circuitry (110) is further configured to limit the lateral inclination of the crane arm (160) to a predefined value if the lateral inclination of the crane arm (160) exceeds the predefined value.

10. The apparatus (100) of any one of claims 7 to 9, wherein the processing circuitry (110) is configured to receive user input data indicating the default opening degree for the valve (175).

11. The apparatus (100) of any one of claims 6 to 10, wherein the processing circuitry (110) is further configured to:set the initial opening degree for the valve (175) to a predefined value for the one of the clockwise slewing motion and the counterclockwise slewing motion of the crane arm (160) that is determined to correspond to slewing the crane arm (160) in the direction against the lateral inclination of the crane arm (160) if the determined initial opening degree for the valve (175) is below a threshold value; orreduce the initial opening degree for the valve (175) for the one of the clockwise slewing motion and the counterclockwise slewing motion of the crane arm (160) that is determined to correspond to slewing the crane arm (160) in the direction against the lateral inclination of the crane arm (160) by a predefined amount, wherein the reduced initial opening degree is limited to zero if it would otherwise fall below zero.

12. The apparatus (100) of any one of claim 1 to 11, wherein the processing circuitry (110) is configured to continuously determine the initial opening degree for the valve (175) over time.

13. A lifting device (150) comprising:a crane arm (160);a hydraulically driven slewing drive (180) for slewing the crane arm (160);a hydraulic system (170) configured to generate flow of hydraulic fluid, wherein the hydraulic system (170) comprises a valve (175) for regulating the supply of hydraulic fluid to the slewing drive (180); andan apparatus (100) for determining an initial opening degree for the valve (175) to initiate a slewing motion of a crane arm (160) according to any of claims 1 to 12.

14. The lifting device (150) of claim 13, further comprising:an inclination sensor (190) configured to generate the first input data (101); anda pressure sensor (195) configured to generate the second input data (102).

15. The lifting device (150) of claim 13 or claim 14, further comprising control circuitry (155) configured to:receive user input data (107) indicating a user input for slewing the crane arm (160); and control the opening degree of the valve (175) based on the user input data (107) to cause slewing motion of the crane arm (160) according to the user input, wherein the control circuitry (155) is configured to initially set the opening degree of the valve (175) to the deter-mined initial opening degree for the valve (175) to initiate the slewing motion of the crane arm (160).

16. The lifting device (150) of any one of claims 13 to 15, wherein the lifting device (150) is a knuckle boom crane.

17. A vehicle (400) having mounted thereon a lifting device (150) according to any one of claims 13 to 16.

18. A method (500) for determining an initial opening degree for a valve regulating the supply of hydraulic fluid to a slewing drive of a lifting device to initiate a slewing motion of a crane arm of the lifting device, the method (500) comprising:receiving (502) first input data indicating an inclination measured at the lifting device; receiving (504) second input data indicating a measured pressure in a hydraulic cylinder of the crane arm; anddetermining (506) the initial opening degree for the valve based on the first and second input data.

19. A non-transitory machine-readable medium having stored thereon a program having a program code for performing the method according to claim 18, when the program is executed on a processor or a programmable hardware.

20. A program having a program code for performing the method according to claim 18, when the program is executed on a processor or a programmable hardware.

Images