Apparatus for determining a target rotational speed for a rotary drive

Abstract

Provided is an (100) for determining a target rotational speed for a rotary drive (130). The apparatus (100) comprises a processing circuitry (110) configured to: receive first input data (101) indicating a target flow rate of hydraulic fluid to be provided by a displacement pump (125) of a crane (120), wherein the displacement pump (125) is driven by the rotary drive (130), and wherein the rotary drive (130) is external to the crane (120); receive second input data (102) indicating a user input, wherein the user input indicates which of a plurality of predefined modes is to be used for determining the target rotational speed; receive third input data (103) indicating the status of the rotary drive (130) or a drive system (140) driving the rotary drive (130); determine the target rotational speed based on the target flow rate and the status according to the mode indicated by the user input; and output control data (105) indicating the determined target rotational speed.

Description

Field

[0001] The present disclosure relates to controlling rotary drives driving displacement pumps of cranes. In particular, examples of the present disclosure relate to an apparatus and a method for determining a target rotational speed for a rotary drive, and a vehicle comprising the apparatus.Background

[0002] Cranes, in particular loader cranes play a pivotal role in various industries, providing efficient lifting and handling capabilities. Various functions of a crane such as lifting, lowering, extending, retracting, rotating, and stabilizing use hydraulic power provided by a displacement pump of the crane.

[0003] The displacement pump of a crane is conventionally provided with a constant speed from a Power Take-Off (PTO) of a vehicle carrying the crane. This leads to high noise of the displacement pump as the constant speed of the PTO is quite high and is highly dependent on the original equipment manufacturer. Due to the constant speed, there are high losses in the displacement pump if the crane is not utilized to its maximum capacity. Furthermore, the performance of the crane is not optimized with conventional technology and there is a significant energy consumption for vehicles.

[0004] Hence, there may be a demand for improved driving of a displacement pump of a crane.Summary

[0005] This demand is met by an apparatus and a method for determining a target rotational speed for a rotary drive, a vehicle, a non-transitory machine-readable medium and a program in accordance with the independent claims. Advantageous embodiments are defined by the dependent claims.

[0006] According to a first aspect, the present disclosure provides an apparatus for determining a target rotational speed for a rotary drive. The apparatus comprises processing circuitry configured to receive first input data indicating a target flow rate of hydraulic fluid to be provided by a displacement pump of a crane. The displacement pump is driven by the rotary drive. The rotary drive is external to the crane. Further, the processing circuitry is configured to receive second input data indicating a user input. The user input indicates which of a plurality of predefined modes is to be used for determining the target rotational speed. The processing circuitry is additionally configured to receive third input data indicating the status of the rotary drive or a drive system driving the rotary drive. In addition, the processing circuitry is configured to determine the target rotational speed based on the target flow rate and the status according to the mode indicated by the user input. The processing circuitry is configured to output control data indicating the determined target rotational speed.

[0007] According to a second aspect, the present disclosure provides a vehicle having mounted thereon a crane. The vehicle comprises the apparatus according to the first aspect. Control circuitry on the vehicle is configured to control the rotary drive based on the control data. The crane comprises at least one of one or more hydraulic cylinders and one or more slewing drives coupled to the displacement pump and drivable by the hydraulic fluid.

[0008] According to a third aspect, the present disclosure provides a method for determining a target rotational speed for a rotary drive. The method comprises receiving first input data indicating a target flow rate of hydraulic fluid to be provided by a displacement pump of a crane. The displacement pump is driven by the rotary drive. The rotary drive is external to the crane. The method further comprises receiving second input data indicating a user input. The user input indicates which of a plurality of predefined modes is to be used for determining the target rotational speed. Additionally, the method comprises receiving third input data indicating the status of the rotary drive or a drive system driving the rotary drive. The method comprises determining the target rotational speed based on the target flow rate and the status using the mode indicated by the user input. In addition, the method comprises outputting control data indicating the determined target rotational speed.

[0009] According to a fourth 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 third aspect, when the program is executed on a processor or a programmable hardware.

[0010] According to a fifth aspect, the present disclosure provides a program having a program code for performing the method according to the third aspect, when the program is executed on a processor or a programmable hardware.

[0011] The rotary drive's rotational speed is controlled according to the requirements of the crane. Accordingly, an optimized hydraulic efficiency may be achieved. Operation of the displacement pump at an optimal flow rate may be achieved, reducing energy consumption and improving the efficiency of the crane's hydraulic system. This optimization may lead to cost savings and longer operational life for the equipment. Also there may be a significant noise reduction in the displacement pump as it may now operate at a lower speed when needed. In total, a performance optimization of the crane operation may be achieved. The inclusion of the user input to select the modes makes the proposed technology user-friendly. Operators can easily switch between modes tailored for specific operational requirements, enhancing usability and operational convenience. Furthermore, by enabling the selection from a plurality of predefined modes through the user input, the proposed technology provides flexibility in operation. This allows for customization according to specific tasks or conditions, improving the adaptability and efficiency of the crane.Brief description of the Figures

[0012] 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 Fig. 1 illustrates an example of an apparatus for determining a target rotational speed for a rotary drive; Fig. 2 illustrates an exemplary first mode for determining the target rotational speed; Fig. 3 illustrates an exemplary second mode for determining the target rotational speed; Fig. 4 illustrates an exemplary third mode for determining the target rotational speed; Fig. 5 illustrates a first exemplary data flow for determining the target rotational speed; Fig. 6 illustrates a second exemplary data flow for determining the target rotational speed; Fig. 7 illustrates an example of a vehicle; and Fig. 8 illustrates a flowchart of an example of a method for determining a target rotational speed for a rotary drive. Detailed Description

[0013] Some 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.

[0014] 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.

[0015] 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.

[0016] 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.

[0017] Fig. 1 schematically illustrates an apparatus 100 for determining a target rotational speed for a rotary drive (rotary actuator, rotary motion drive) 130. The rotary drive 130 is configured to produce (provide) controlled rotational movement. The target rotational speed denotes the desired or intended speed at which the rotary drive 130 should rotate. In other words, the target rotational speed refers to the desired or intended speed of the rotational movement to be provided by the rotary drive 130.

[0018] As schematically indicated in Fig. 1, a displacement pump 125 of a crane 120 is driven by the rotary drive 130 to provide hydraulic power. For example, the hydraulic power may be provided by means of a flow of hydraulic fluid caused (generated) by the displacement pump 125 when driven by the rotary drive 130. The hydraulic power provided by the displacement pump 125 is used by one or more consumers of the crane 120 (not illustrated in Fig. 1). The one or more consumers of the crane 120 are hydraulically coupled to the displacement pump 125. The displacement pump 125 and the one or more consumers of the crane 120 form a hydraulic system of the crane 120. For example, the one or more consumers may be one or more hydraulic cylinders and / or one or more slewing drives of the crane 120 for providing various functions of the crane 120 such as lifting, lowering, extending, retracting, rotating, and stabilizing. For reasons of simplicity, various elements of the crane 120 such as its one or more hydraulic cylinders, one or more slewing drives, (crane) base, boom (crane arm) or outriggers (crane legs) are not illustrated in Fig. 1.

[0019] The rotary drive 130 is external to the crane 120. In other words, the rotary drive 130 is not part of the crane 120. The rotary drive 130 may be any device or system capable of converting energy into mechanical rotation (rotational movement) in a controlled manner. For example, the rotary drive 130 may be an electric rotary drive comprising one or more electric motors for generating the rotational movement. According to examples of the present disclosure, the rotary drive 130 may be an electric rotary drive on a vehicle having mounted thereon (holding, carrying) the crane 120. In alternative examples, the rotary drive 130 may be a PTO driven by a drive system 140 (e.g., a combustion engine and optionally a gearbox). According to examples of the present disclosure, the rotary drive 130 may be a PTO of a vehicle having mounted thereon the crane 120. The vehicle may be a land vehicle (e.g., wheeled, tracked or railed) or a watercraft (e.g., a ship, a boat or a barge). For example, the crane 120 may be mounted to vehicle such as a truck for loading and unloading goods onto and from the vehicle. The rotary drive 130, in particular when implemented as electric rotary drive, may be detachably attached to the vehicle. In other examples, the rotary drive 130 may be fixedly attached to the vehicle. For reasons of clarity, the vehicle is not shown in Fig. 1.

[0020] In general, the crane 120 may be any type of crane using a displacement pump to provide hydraulic power. For example, the crane 120 may be a knuckle boom crane such as a loader crane for loading and unloading goods (loads). In other examples, the crane 120 may be the crane section of a mobile crane (with the vehicle being the mobile platform having mounted thereon the crane section).

[0021] The apparatus 100 may be part of the crane 120. According to examples, crane control circuitry (crane controller) 121 for controlling operation of the crane 120 may comprise the apparatus 100. The crane control circuitry 121 may, e.g., be coupled to the displacement pump 125 and control operation of the displacement pump 125 and optionally further elements of the crane 120. In other examples, the apparatus 100 and the crane control circuitry 121 may be separate elements of the crane. In alternative examples, the apparatus 100 may be external to the crane 120, i.e., not be part of the crane 120. For example, a computing cloud communicatively coupled to the crane 120 (e.g., via a wireless connection) may comprise or be the apparatus 100. In still other examples, the vehicle having mounted thereon the crane 120 may comprise the apparatus 100.

[0022] The apparatus 100 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 neuromorphic 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.

[0023] The processing circuitry 110 is configured to receive first input data 101. The first input data 101 indicate (are encoded with information about) a target flow rate of hydraulic fluid to be provided (delivered) by the displacement pump 125 of the crane 120. The target flow rate denotes the desired, demanded or intended flow rate at which hydraulic fluid should flow through the hydraulic system of the crane 120. The hydraulic fluid is to be supplied (pumped) at the target flow rate by the displacement pump 125. For example, the target flow rate may indicate how much volume (e.g., how many liters) of hydraulic fluid the displacement pump 125 should deliver per unit of time (e.g., per second or per minute). 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. The first input data 101 may, e.g., be received from the crane control circuitry 121. The crane control circuitry 121 controls the operation of the crane 120 and is, hence, aware of or able to calculate the required flow rate of hydraulic fluid for the (e.g., intended) operation of the crane 120. However, the present disclosure is not limited thereto. In other examples, the first input data 101 may be received from another entity (element, circuitry) of the crane 120.

[0024] Further, the processing circuitry 110 is configured to receive second input data 102 indicating a user input. The user input indicates which of a plurality of predefined (operational) modes is to be used for determining the target rotational speed. In other words, the user input specifies a particular mode among several (i.e., two or more) predefined options, and this chosen mode dictates how the target rotational speed is determined. The plurality of predefined modes are different from each other. In particular, the plurality of predefined modes differ from each other in the way the target rotational speed is determined based on the input data received by the processing circuitry 110. For example, the second input data 102 may be received from a remote control (not illustrated in Fig. 1). The remote control is a device for an operator (user) of the crane 120 for controlling the crane 120 from a distance. However, the present disclosure is not limited thereto. In other examples, the second input data 102 may be received from another entity such as an element or circuitry of the crane 120 (e.g., a Human-Machine Interface, HMI, of the crane 120), a mobile device (e.g., a mobile phone, a laptop-computer or a tablet-computer) of the operator of the crane 120 or a remote server.

[0025] The processing circuitry 110 is additionally configured to receive third input data 103 indicating the status of the rotary drive 130 or the drive system 140 driving the rotary drive 130. The status of the rotary drive 130 or the drive system 140 driving the rotary drive 130 refers to the operational condition, i.e., the current state or operational parameters of the rotary drive 130 or the drive system 140. For example, the status of the rotary drive 130 may be one or more of a current (present) rotational speed of the rotary drive 130, a current (present) load or utilization of the rotary drive 130 (e.g., a current torque utilization of the rotary drive 130). Similarly, the status of the drive system 140 driving the rotary drive 130 may be one or more of a current (present) rotational speed of the drive system 140, a current (present) load or utilization of the drive system 140 (e.g., a current torque utilization of the drive system 140).

[0026] The processing circuitry 110 is configured to determine the target rotational speed for the rotary drive 130 based on the target flow rate and the status according to the mode indicated by the user input. In other words, according to the mode selected by the user, the processing circuitry 110 determines the target rotational speed using the target flow rate indicated by the first input data 101 and the status indicated by the third input data 103 as input for the determination. The way the target rotational speed is determined by the processing circuitry 110 depends on the mode indicated by the user input.

[0027] The processing circuitry 110 is configured to output control data 105 indicating the determined target rotational speed. The control data 105 are for controlling the rotational speed of the rotary drive 130. The control data 105 may be output by the processing circuitry 110 to various entities - depending on the implementation of the rotary drive 130. For example, the processing circuitry 110 may be configured to output the control data 105 to the rotary drive 130 such that control circuitry of the rotary drive 130 may control the rotary drive 130 to adjust its rotational speed to the determined target rotational speed. In other examples, the processing circuitry 110 may be configured to output the control data 105 to control circuitry for the rotary drive 130 external to the rotary drive 130 such that the external control circuitry may control the rotary drive 130 to adjust its rotational speed to the determined target rotational speed. For example, if the rotary drive is an electric rotary drive on a vehicle having mounted thereon the crane 120, the processing circuitry 110 may be configured to output the control data 105 to the electric rotary drive such that control circuitry of the electric rotary drive may control the electric rotary drive to adjust its rotational speed to the determined target rotational speed. In case the rotary drive 130 is driven by the drive system 140, the processing circuitry 110 may be configured to output the control data 105 to the drive system 140 or control circuitry for the drive system 140 external to the drive system 140 such that the drive system 140 is controlled to adjust the driving of the rotary drive 130 such that the rotational speed of the rotary drive 130 is adjusted to the determined target rotational speed. For example, if the rotary drive 130 is a PTO of a vehicle having mounted thereon the crane 120, the processing circuitry 110 may be configured to output the control data 105 to the vehicle such that vehicle control circuitry of the vehicle may control the drive system 140 of the vehicle (e.g., a combustion engine of the vehicle) based on the control data 105.

[0028] The determination of the target rotational speed according to the proposed technology allows for flexible and precise control of the rotary drive 130's rotational speed based on varying operational requirements (indicated by the target flow rate and the status) and user preferences (determined by the mode indicated by the user input). The rotary drive 130's rotational speed is controlled according to the requirements of the crane 120, which are indicated by the target flow rate. Accordingly, an optimized hydraulic efficiency may be achieved. The apparatus 100 may, e.g., ensure that the displacement pump 125 operates at an optimal flow rate, reducing energy consumption and improving the efficiency of the hydraulic system. Compared to conventional approaches, there may be very low losses in the system even if the crane 120 is operated at a very low capacity. This may make the crane 120 highly energy efficient. This optimization may lead to cost savings and longer operational life for the equipment. Also there may be a significant noise reduction in the displacement pump 125 as it may now operate at a lower speed when needed. In total, a performance optimization of the crane operation may be achieved. The inclusion of the user input to select the modes makes the apparatus 100 user-friendly. The user input allows to customize the determination of the target rotational speed according to the needs or preferences of the user. Operators of the crane 120 may easily switch between modes tailored for specific operational requirements, enhancing usability and operational convenience. Furthermore, by enabling the selection from a plurality of predefined modes through user input, the apparatus 100 provides flexibility in operation. This allows for customization according to specific tasks or conditions, improving the adaptability and efficiency of the crane 120.

[0029] The first to third input data 103 as well as other input data to the processing circuitry 110 may be real-time data (i.e., data that is delivered / received immediately after collection / generation without significant delay). This may ensure that the target rotational speed can be dynamically adjusted. This real-time feedback loop helps in maintaining optimal performance and safety.

[0030] In the following, three exemplary modes for determining the target rotational speed based on the target flow rate and the status will be described in greater detail with reference to Figs. 2 to 4. However, it is to be noted that the present disclosure is not limited thereto. Other, additional or less modes may be used according to examples of the present disclosure.

[0031] Fig. 2 schematically illustrates an exemplary first mode 200 for determining the target rotational speed for the rotary drive 130. In the first mode 200, the processing circuitry 110 is configured to dynamically determine the target rotational speed based on at least the target flow rate indicated by the first input data 101 and the status indicated by the third input data 103. In other words, the processing circuitry 110 is configured to determine the target rotation speed substantially in real-time based on the inputs. For example, the processing circuitry 110 may be configured to determine the target rotational speed at a rate of 1 Hz or more, 10 Hz or more, 50 Hz or more, or 100 Hz or more in the first mode 200.

[0032] In the first mode 200, the determined target rotational speed for the rotary drive 130 dynamically follows the target flow rate, i.e., the demanded volume of hydraulic fluid per unit time, and the status of the rotary drive 130 or its driving system 140. This dynamic determination allows to adjust the rotational speed of the rotary drive 130 substantially in real-time to ensure optimal performance and adapt to changing conditions. The first mode 200 may be used for fast, dynamic operation of the crane 120.

[0033] The processing circuitry 110 may take into account further inputs for determining the target rotational speed for the rotary drive 130 in the first mode 200. For example, in the first mode 200, the processing circuitry 200 may be configured to determine the target rotational speed further based on data 201 indicating a displacement per revolution of the displacement pump 125 (e.g., liters of hydraulic fluid displaced per revolution). The data 201 may, e.g., be received from the control circuitry 121 or the displacement pump 125. The displacement pump 125's displacement per revolution may be constant or variable. Accordingly, the value indicated by the data 201 for the displacement per revolution of the displacement pump 125 may be a constant value or change over time. The displacement pump 125's displacement per revolution may, e.g., be measured via a corresponding sensor. In other examples, the data 201 may indicate the maximum (possible, supported) displacement per revolution of the displacement pump 125 (e.g., if the displacement pump 125's displacement per revolution is not measured). Knowing the displacement per revolution of the displacement pump 125 allows to more precisely estimate the flow rate of hydraulic fluid caused by the displacement pump 125 for the various possible rotational speeds of the rotary drive 130. Accordingly, the rotational speed required to achieve the target flow rate indicated by the first input data 101 may be determined more precisely.

[0034] Alternatively or additionally, the processing circuitry 110 may, in the first mode 200, be configured to determine the target rotational speed further based on data 202 indicating a predefined rotational speed offset for increasing the rotational speed of the rotary drive 130. The predefined rotational speed offset refers to a set value or adjustment factor that is used to increase the determined target rotational speed for the rotary drive 130 by a certain amount. For example, if the target rotational speed for the rotary drive 130 is, based on the target flow rate indicated by the first input data 101, the status indicated by the third input data 103 and optionally further inputs such as the data 201, determined to be X revolutions per unit time and the predefined rotational speed offset is Y revolutions per unit time, the resulting target rotational speed is Z = X + Y revolutions per time unit. In other examples, if an adjustment factor A ≥ 1 is used instead of the set value Y, the resulting target rotational speed is Z = X . A revolutions per time unit. The predefined rotational speed offset allows to add a safety margin to the target rotational speed for the rotary drive 130. Accordingly, too low rotational speeds of the rotary drive 130 may be avoided. As a consequence, unwanted limitation of the hydraulic system's and, hence, the crane 120's performance may be avoided. The data 202 may, e.g., be received from the control circuitry 121 or any other element or circuitry of the crane 120. For example, the predefined rotational speed offset may depend on the current application or use of the crane (e.g., lifting of a load, rotating of the boom relative to the crane base, changing a positioning of the crane arm, etc.). In other examples, the predefined rotational speed offset may be determined (set) by a user input at, e.g., the remote control.

[0035] The processing circuitry 110 may be configured to determine the target rotational speed in the first mode 200 using a predefined computational model. The computational model is a mathematical representation (e.g., a set of mathematical equations) for determining the target rotational speed for the rotary drive 130 taking into account the target flow rate indicated by the first input data 101, the status indicated by the third input data 103 and optionally further inputs such as one or more of the data 201 and 202. The computational model may use various signal and / or data processing operations such as signal / data addition, subtraction, multiplication, division, integration, derivation, filtering (e.g., discrete, continuous or both), delaying, etc. to determine the target rotational speed based on the various inputs to the processing circuitry 110.

[0036] An exemplary second mode 300 for determining the target rotational speed for the rotary drive 130 is illustrated in Fig. 3. Compared to the first mode 200, the target rotational speed for the rotary drive 130 is determined (e.g., raised or lowered) in a stepped manner in the second mode 300.

[0037] In the second mode 300, the processing circuitry 110 is configured to periodically determine an auxiliary value for the target rotational speed based on the target flow rate indicated by the first input data 101 and the status indicated by the third input data 103. In other words, the processing circuitry 110 is configured to determine the auxiliary value for the target rotational speed at regular time intervals, not continuously. For example, the processing circuitry 110 may be configured to determine the auxiliary value for the target rotational speed at a rate of 0.5 Hz or less, 0.25 Hz or less, or 0.1 Hz or less in the second mode 300.

[0038] The processing circuitry 100 may be configured to determine the auxiliary value for the target rotational speed in the second mode 300 using the predefined computational model used in the first mode 200 for determining the target rotational speed or another computational model. Furthermore, the processing circuitry 110 may take into account further inputs for determining the auxiliary value for the target rotational speed for the rotary drive 130 in the second mode 300 - analogously to what is described above for the determination of the target rotational speed in the first mode 200. For example, in the second mode 300, the processing circuitry 110 may be configured to determine the auxiliary value for the target rotational speed further based on at least one of the data 201 indicating the displacement per revolution of the displacement pump 125 and the data 202 indicating the predefined rotational speed offset for increasing the rotational speed of the rotary drive 130.

[0039] In the second mode 300, the processing circuitry 110 is further configured to compare the determined auxiliary value for the target rotational speed to a current value of the rotational speed of the rotary drive 130. For example, the processing circuitry 110 may be configured to receive data indicating the current value of the rotational speed of the rotary drive 130. This data may, e.g., be received from the rotary drive 130, the control circuitry for the rotary drive 130 external to the rotary drive 130, the drive system 140 or the control circuitry for the drive system 140 external to the drive system 140. However, the present disclosure is not limited thereto. For example the data indicating the current value of the rotational speed of the rotary drive 130 may be received from any other circuitry of a vehicle having mounted thereon the crane 120.

[0040] Based on the result of the comparison, the current value of the target rotational speed is changed or not. If the difference between the determined auxiliary value for the target rotational speed and the current value of the rotational speed satisfies a criterion, the processing circuitry 110 is configured to set the auxiliary value for the target rotational speed as the target rotational speed. The criterion may be manyfold. For example, the criterion may be that the absolute difference between the determined auxiliary value for the target rotational speed and the current value of the rotational speed is greater than a first threshold value (e.g., more than 50, 100, 150, 200 or 250 revolutions per minute). In alternative examples, the criterion may be that the relative difference between the determined auxiliary value for the target rotational speed and the current value of the rotational speed is greater than a second threshold value (e.g., 5 % or more, 10 % or more, 15 % or more, 20 % or more, or 25 % or more). However, the present disclosure is not limited to the aforementioned exemplary criteria. Any other suitable criterion may be used instead.

[0041] If the difference between the determined auxiliary value for the target rotational speed and the current value of the rotational speed does not satisfy the criterion, the processing circuitry 110 is further configured to set the current value of the rotational speed as the target rotational speed in the second mode 300. In other words, the current value of the target rotational speed is not changed by the processing circuitry 110 if the difference between the determined auxiliary value for the target rotational speed and the current value of the rotational speed does not satisfy the criterion.

[0042] In the second mode 300, the determined target rotational speed for the rotary drive 130 follows the target flow rate and the status of the rotary drive 130 or its driving system 140 step-wise. In other words, the determined target rotational speed for the rotary drive 130 is step-wise increased or decreased according to the target flow rate and the status of the rotary drive 130 or its driving system 140. Compared to the first mode 200, the step-wise adaptation of the target rotational speed of the second mode 300 requires less computational efforts but allows to achieve good performance and sufficient adaptation to changing conditions. Additionally, the noise in the displacement pump 125 may be further reduced compared to the first mode 200 as the change of the rotary drive 130's rotational speed is less dynamic. The second mode 300 may be used for slow, less dynamic operation of the crane 120.

[0043] Fig. 4 illustrates an exemplary third mode 400 for determining the target rotational speed for the rotary drive 130. In the third mode 400, the processing circuitry 110 is configured to constantly (permanently) determine a first predefined rotational speed to be the target rotational speed. The first predefined rotational speed is a constant rotational speed. The processing circuitry 110 may, e.g., be configured to read data 401 indicating the first predefined rotational speed from a memory coupled to the processing circuitry 110. In other examples, the processing circuitry 110 may be configured to receive the data 401 from the crane control circuitry 121 or any other entity (element, circuitry) of the crane 120. For example, the first predefined rotational speed may be predefined by a manufacturer of the crane 120 or a manufacturer of the displacement pump 125. In other examples, the first predefined rotational speed may be determined (set) by a user input at, e.g., the remote control. Accordingly, the data 401 may be received from the remote control. The first predefined rotational speed is independent of the target flow rate indicated by the first input data 101 and the status indicated by the third input data 103. Accordingly, the determined target rotational speed for the rotary drive 130 is independent of the target flow rate indicated by the first input data 101 and the status indicated by the third input data 103 in the third mode 400.

[0044] The third mode 400 allows to provide the crane 120 with constant hydraulic power sufficient for specific applications. As the rotary drive 130's rotational speed is not changed in the third mode 400, noise in the displacement pump 125 is constant. Furthermore, the third mode 400 requires only little computational efforts.

[0045] The specific operation of the crane 120 may further be considered when determining the target rotational speed for the rotary drive 130. This is exemplarily illustrated in Fig. 5 showing a data flow 500 in the processing circuitry 110 for determining the target rotational speed for the rotary drive 130.

[0046] In addition to the above described input data, the processing circuitry 110 may be configured to receive fourth input data 501. The fourth input data 501 indicates whether the crane 120 is driving a hydraulic cylinder or a slewing drive of (for) a crane arm (boom) with the hydraulic fluid provided by the displacement pump 125, or whether the crane 120 is driving a hydraulic cylinder of an outrigger with the hydraulic fluid provided by the displacement pump 125. For example, the processing circuitry 110 may be configured to receive the data 501 from the crane control circuitry 121 or any other entity (element, circuitry) of the crane 120.

[0047] The fourth input data 501 are analyzed by the processing circuitry 110 as indicated by block 510 in Fig. 5. If the fourth input data 501 indicate that the crane 120 is driving the hydraulic cylinder or the slewing drive of the crane arm with the hydraulic fluid, the processing circuitry 110 is configured to determine the target rotational speed based on the target flow rate indicated by the first input data 101 and the status indicated by the third input data according to the mode indicated by the user input of the second input data 102. For example, the processing circuitry 110 may determine the target rotational speed according to one of the modes described above. This is exemplarily illustrated by block 520 in Fig. 5. For example, the processing circuitry 110 may be configured to enable (activate) the processing represented by block 520 in Fig. 5 if the fourth input data 501 indicate that the crane 120 is driving the hydraulic cylinder or the slewing drive of the crane arm with the hydraulic fluid.

[0048] On the other hand, if the fourth input data 501 indicate that the crane 120 is driving the hydraulic cylinder of the outrigger with the hydraulic fluid, the processing circuitry 110 is configured to (e.g., constantly, permanently) determine a second predefined rotational speed to be the target rotational speed. For example, the processing circuitry 110 may be configured to constantly (permanently) determine the second predefined rotational speed to be the target rotational speed while the fourth input data 501 indicate that the crane 120 is driving the hydraulic cylinder of the outrigger with the hydraulic fluid. This is exemplarily illustrated by block 530 in Fig. 5. The second predefined rotational speed is a constant rotational speed. The processing circuitry 110 may, e.g., be configured to read data 502 indicating the first predefined rotational speed from a memory coupled to the processing circuitry 110. In other examples, the processing circuitry 110 may be configured to receive the data 502 from the crane control circuitry 121 or any other entity (element, circuitry) of the crane 120. For example, the second predefined rotational speed may be predefined by a manufacturer of the crane 120 or a manufacturer of the displacement pump 125. In other examples, the second predefined rotational speed may be determined (set) by a user input at, e.g., the remote control. Accordingly, the data 502 may be received from the remote control. The second predefined rotational speed is independent of the target flow rate indicated by the first input data 101 and the status indicated by the third input data 103. Accordingly, the determined target rotational speed for the rotary drive 130 is independent of the target flow rate indicated by the first input data 101 and the status indicated by the third input data 103. The second predefined rotational speed may be equal to or be different from the first predefined rotational speed.

[0049] A multiplexer (switch) 540 is illustrated in Fig. 5 to exemplarily illustrate that either the second predefined rotational speed or the rotational speed determined based on the target flow rate indicated by the first input data 101 and the status indicated by the third input data according to the mode indicated by the user input is output as the target rotational speed - depending on whether the fourth input data 501 indicate that the crane 120 is driving the hydraulic cylinder or the slewing drive of the crane arm (boom) with the hydraulic fluid, or whether the fourth input data 501 indicate that the crane 120 is driving the hydraulic cylinder of the outrigger with the hydraulic fluid. In Fig. 5, the switching behavior of the multiplexer (switch) 540 is controlled according to the fourth input data 501 provided by block 510.

[0050] The crane 120 has different hydraulic power demands depending on its operation. This is reflected in the data flow 500 by taking into account the fourth input data 501. If the hydraulic power is used to drive the hydraulic cylinder(s) of the crane 120's outrigger(s), a specific constant hydraulic power is desired (or required). By outputting the second predefined rotational speed as the target rotational speed, it may be ensured that the rotary drive 130 provides the desired (required) input power to the displacement pump. On the other hand, if the hydraulic power is used to drive the hydraulic cylinder(s) or the slewing drive(s) of the crane 120's crane arm, the above beneficial effects may be achieved by determining the target rotational speed based on the target flow rate indicated by the first input data 101 and the status indicated by the third input data according to the mode indicated by the user input.

[0051] Fig. 6 illustrates another exemplary data flow 600 summarizing the above described aspects for determining the target rotational speed for the rotary drive 130 and highlighting some further optional aspects of the proposed technology.

[0052] As described above, the first input data 101, the second input data 102 and the third input data 103 are received. The user input indicated by the second input data 102 is analyzed. This is illustrated by block 610 in Fig. 1. In the example of Fig. 6, the three exemplary modes 200, 300 and 400 for determining the target rotational speed are used. As indicated above, additional, less or different modes may be used. Depending on which of the predefined modes 200, 300 and 400 is indicated by the user input, the corresponding one of the models 200, 300 and 400 is enabled (activated) to determine the target rotational speed based on the target flow rate indicated by the first input data 101 and the status indicated by the third input data 103.

[0053] The output of the selected model is received at a block 620 for further processing. In the following, three exemplary modifications of the target rotational speed determined via one of the models 200, 300 and 400 are described. The exemplary modifications are represented by locks 625, 630 and 640 in Fig. 6. It is to be noted that each of these modifications is optional. One or more of the modifications may be omitted according to the examples of the present disclosure.

[0054] Block 625 represents an optional change rate limitation. The processing circuitry 110 may be configured to modify, prior to outputting the output data 105, the determined target rotational speed to comply with a maximum (allowed, supported) change rate of the rotary drive 130's rotational speed if the determined target rotational speed changes by more than the maximum change rate of the rotary drive 130's rotational speed. In other words, the change of the determined target rotational speed over time is limited. This allows to protect the displacement pump 125 from too high accelerations or decelerations, which might damage the displacement pump 125. The maximum change rate of the rotary drive 130's rotational speed may depend on the type (model) of the displacement pump 125.

[0055] Furthermore, as indicated by block 630 in Fig. 6, the processing circuitry 110 may be further configured to modify, prior to outputting the output data 105, the determined target rotational speed to comply with first minimum and maximum rotational speeds 631 and 632 related to (defined by) the rotary drive 130 if the determined target rotational speed is below the first minimum rotational speed 632 or above the first maximum rotational speed 631. For example, the determined target rotational speed may be limited to the first minimum rotational speed 632 if the determined target rotational speed is below the first minimum rotational speed 632. Analogously, the determined target rotational speed may be limited to the first maximum rotational speed 631 if the determined target rotational speed is above the first maximum rotational speed 631. This allows to protect the rotary drive 130 from too high or too low rotational speeds, which might damage the rotary drive 130. The first minimum and maximum rotational speeds 631 and 632 may depend on the type (model) of the rotary drive 130.

[0056] As indicated by block 640 in Fig. 6, the processing circuitry 110 may be further configured to modify, prior to outputting the output data 105, the determined target rotational speed to comply with second minimum and maximum rotational speeds 641 and 642 related to (defined by) the displacement pump 125 if the determined target rotational speed is below the second minimum rotational speed 642 or above the second maximum rotational speed 641. For example, the determined target rotational speed may be limited to the second minimum rotational speed 642 if the determined target rotational speed is below the second minimum rotational speed 642. Analogously, the determined target rotational speed may be limited to the second maximum rotational speed 641 if the determined target rotational speed is above the second maximum rotational speed 641. This allows to protect the displacement pump 125 from too high or too low rotational speeds, which might damage the displacement pump 125. The second minimum and maximum rotational speeds 641 and 642 may depend on the type (model) of the displacement pump 125.

[0057] As indicated by block 680 in Fig. 6, the processing circuitry 110 may further be configured to determine whether the target flow rate indicated by the first input data 101 is zero for more than a predefined period of time. For example, the processing circuitry 110 may use a counter-to-zero which starts counting to zero as soon as and for as long as the target flow rate indicated by the first input data 101 is zero. The time period it takes from counting to zero from the start value of the counter-to-zero is the predefined period of time.

[0058] The block 690 receives the determination result of the block 680 and controls the further processing of the determined target rotational speed by blocks 650 and 655. If the target flow rate of hydraulic fluid is zero for more than the predefined period of time, the block 690 controls the block 655 to forward a predefined value 691 for the target rotational speed to block 660. Else, the block 690 controls the block 655 to not forward the predefined value 691 to the block 660. In this case, the target rotational speed determined by one of the models 200, 300 and 400 and optionally modified by one of the blocks 625, 630 and 640 is forwarded to the block 660. The predefined value 691 for the target rotational speed may, e.g., be zero. Alternatively, the predefined value 691 may be a non-zero value. For example, the predefined value 691 may be 250 revolutions per minute or less, 200 revolutions per minute or less, 150 revolutions per minute or less, 100 revolutions per minute or less, or 50 revolutions per minute or less. In other words, if the target flow rate of hydraulic fluid is zero for more than the predefined period of time, the processing circuitry 110 may be configured to determine the target rotational speed to be the predefined value 691. Else, the processing circuitry 110 may be configured to determine the target rotational speed based on the target flow rate indicated by the first input data 101 and the status indicated by the third input data 103 according to the mode indicated by the user input. As discussed above, the target flow rate indicated by the first input data 101 describes the crane 120's demand for hydraulic power. If the target flow rate indicated by the first input data 101 is zero for a longer period of time, the crane 120 is likely not operated. Accordingly, by determining the target rotational speed to be the predefined value 691, the rotational speed of the rotary drive 130 may be adapted to the crane 120's low demand for hydraulic power. This may allow to reduce the energy consumption and improve the efficiency of the crane 120's hydraulic system. This optimization may lead to cost savings. Also there may be a significant noise reduction in the displacement pump as it may now operate at a lower speed.

[0059] The adaptation of the target rotational speed depending on whether the crane 120 is driving the hydraulic cylinder or the slewing drive of the crane arm (boom) with the hydraulic fluid provided by the displacement pump 125, or whether the crane 120 is driving the hydraulic cylinder of the outrigger with the hydraulic fluid provided by the displacement pump 125, is illustrated in Fig. 6 by block 670. The block 670 receives the fourth input data 501 and analyzes them as described above. If the fourth input data 501 indicate that the crane 120 is driving the hydraulic cylinder or the slewing drive of the crane arm with the hydraulic fluid, the target rotational speed determined by one of the models 200, 300 and 400 and optionally modified by one of the blocks 625, 630 and 640 is output as the output data 105.

[0060] On the other hand, if the fourth input data 501 indicate that the crane 120 is driving the hydraulic cylinder of the outrigger with the hydraulic fluid, the second predefined rotational speed is determined to be the target rotational speed and output as the output data 105.

[0061] Fig. 7 illustrates a truck as an exemplary vehicle 700 having mounted thereon (holding) a loader crane (knuckle boom crane) as an exemplary crane 720. In the example of Fig. 7, the crane 720 comprises hydraulic cylinders 721, 722 and 723 for driving (moving) the crane arm 724 of the crane 720. Additionally, the crane 720 comprises hydraulic cylinders 725 for driving (moving) the outriggers 726. Further illustrated in Fig. 7 is the slewing drive 728 for rotating the crane arm 724 relative to the base 727 of the crane. The hydraulic cylinders and the slewing drive(s) are hydraulically coupled to the displacement pump 125 of the crane 720 and form the hydraulic system of the vehicle 700. The hydraulic cylinders and the slewing drive(s) are drivable (driven) by the displacement pump 125 of the crane 720. The displacement pump 125 of the crane 720 is driven by the rotary drive 130 on the vehicle 700.

[0062] The vehicle 700 further comprises the apparatus 100 according to the present disclosure for determining a target rotational speed for the rotary drive 130. As described above, the rotary drive 130 may, e.g., be a PTO of the vehicle 700. For example, the PTO may be driven by a combustion engine and optionally a gearbox of the vehicle 700. In alternative examples, the rotary drive 130 may be an electric rotary drive on the vehicle 700. For reasons of simplicity, the rotary drive 130 is illustrated schematically in Fig. 7.

[0063] Control circuitry 710 on the vehicle 710 is configured to control the rotary drive 130 based on the control data 105 output by the apparatus 100. As described above, the control circuitry 710 may be manifold depending on the type of rotary drive.

[0064] Compared to conventional vehicles, the vehicle 700 may achieve an optimized hydraulic efficiency, reduced energy consumption, improved noise emission and enhanced usability and operational convenience.

[0065] For further highlighting the driving of displacement pumps of cranes described above, Fig. 8 illustrates a flowchart of a method 800 for determining a target rotational speed for a rotary drive. The method 800 comprises receiving 802 first input data indicating a target flow rate of hydraulic fluid to be provided by a displacement pump of a crane. The displacement pump is driven by the rotary drive. The rotary drive is external to the crane. The method 800 further comprises receiving 804 second input data indicating a user input. The user input indicates which of a plurality of predefined modes is to be used for determining the target rotational speed. Additionally, the method 800 comprises receiving 806 third input data indicating the status of the rotary drive or a drive system driving the rotary drive. The method 800 comprises determining 808 the target rotational speed based on the target flow rate and the status using the mode indicated by the user input. In addition, the method 800 comprises outputting 810 control data indicating the determined target rotational speed.

[0066] Analogously to what is described above, the method 800 may allow performance optimization of the crane operation, noise reduction, enhancement of usability and operational convenience as well as flexibility in operation.

[0067] More details and aspects of the method 800 are explained in connection with the proposed technique or one or more examples described above (e.g., Fig. 1 or Fig. 7). The method 800 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.

[0068] The examples described herein may be summarized as follows: An example (e.g., example 1) relates to an apparatus for determining a target rotational speed for a rotary drive. The apparatus comprises processing circuitry configured to receive first input data indicating a target flow rate of hydraulic fluid to be provided by a displacement pump of a crane. The displacement pump is driven by the rotary drive. The rotary drive is external to the crane. Further, the processing circuitry is configured to receive second input data indicating a user input. The user input indicates which of a plurality of predefined modes is to be used for determining the target rotational speed. The processing circuitry is additionally configured to receive third input data indicating the status of the rotary drive or a drive system driving the rotary drive. In addition, the processing circuitry is configured to determine the target rotational speed based on the target flow rate and the status according to the mode indicated by the user input. The processing circuitry is configured to output control data indicating the determined target rotational speed.

[0069] Another example (e.g., example 2) relates to a previous example (e.g., example 1) or to any other example, wherein the plurality of predefined modes comprise a first mode in which the processing circuitry is configured to dynamically determine the target rotational speed based on the target flow rate and the status.

[0070] Another example (e.g., example 3) relates to a previous example (e.g., example 2) or to any other example, wherein the processing circuitry is configured to determine the target rotational speed at a rate of 10 Hz or more in the first mode.

[0071] 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, in the first mode, the processing circuitry is configured to determine the target rotational speed further based on at least one of data indicating a displacement per revolution of the displacement pump and data indicating a predefined rotational speed offset for increasing the rotational speed of the rotary drive.

[0072] Another example (e.g., example 5) relates to a previous example (e.g., one of the examples 1 to 4) or to any other example, wherein the plurality of predefined modes comprise a second mode in which the processing circuitry is configured to: periodically determine an auxiliary value for the target rotational speed based on the target flow rate and the status; compare the determined auxiliary value for the target rotational speed to a current value of the rotational speed of the rotary drive; and set the auxiliary value for the target rotational speed as the target rotational speed if the difference between the determined auxiliary value for the target rotational speed and the current value of the rotational speed satisfies a criterion.

[0073] Another example (e.g., example 6) relates to a previous example (e.g., example 5) or to any other example, wherein, in the second mode, the processing circuitry is further configured to set the current value of the rotational speed as the target rotational speed if the difference between the determined auxiliary value for the target rotational speed and the current value of the rotational speed does not satisfy the criterion.

[0074] Another example (e.g., example 7) relates to a previous example (e.g., one of the examples 5 or 6) or to any other example, wherein the processing circuitry is configured to determine the auxiliary value for the target rotational speed at a rate of 0.5 Hz or less in the second mode.

[0075] Another example (e.g., example 8) relates to a previous example (e.g., one of the examples 5 to 7) or to any other example, wherein, in the second mode, the processing circuitry is configured to determine the auxiliary value for the target rotational speed further based on at least one of data indicating a displacement per revolution of the displacement pump and data indicating a predefined rotational speed offset for increasing the rotational speed of the rotary drive.

[0076] Another example (e.g., example 9) relates to a previous example (e.g., one of the examples 1 to 8) or to any other example, wherein the plurality of predefined modes comprise a third mode in which the processing circuitry is configured to constantly determine a first predefined rotational speed to be the target rotational speed.

[0077] Another example (e.g., example 10) relates to a previous example (e.g., example 9) or to any other example, wherein the first predefined rotational speed is independent of the target flow rate and the status.

[0078] Another example (e.g., example 11) relates to a previous example (e.g., one of the examples 1 to 10) or to any other example, wherein the processing circuitry is further configured to: determine whether the target flow rate of hydraulic fluid indicated by the first input data is zero for more than a predefined period of time; if the target flow rate of hydraulic fluid is zero for more than the predefined period of time, determine the target rotational speed to be a predefined value; and else, determine the target rotational speed based on the target flow rate and the status according to the mode indicated by the user input.

[0079] 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 further configured to modify, prior to outputting the output data, the determined target rotational speed to comply with first minimum and maximum rotational speeds related to the rotary drive if the determined target rotational speed is below the first minimum rotational speed or above the first maximum rotational speed.

[0080] Another example (e.g., example 13) relates to a previous example (e.g., one of the examples 1 to 12) or to any other example, wherein the processing circuitry is further configured to modify, prior to outputting the output data, the determined target rotational speed to comply with second minimum and maximum rotational speeds related to the displacement pump if the determined target rotational speed is below the second minimum rotational speed or above the second maximum rotational speed.

[0081] Another example (e.g., example 14) relates to a previous example (e.g., one of the examples 1 to 13) or to any other example, wherein the processing circuitry is further configured to: receive fourth input data indicating whether the crane is driving a hydraulic cylinder or a slewing drive of a crane arm or an outrigger with the hydraulic fluid; if the fourth input data indicate that the crane is driving the hydraulic cylinder or the slewing drive of the crane arm with the hydraulic fluid, determine the target rotational speed based on the target flow rate and the status according to the mode indicated by the user input; and if the fourth input data indicate that the crane is driving the hydraulic cylinder of the outrigger with the hydraulic fluid, determine a second predefined rotational speed to be the target rotational speed, wherein the second predefined rotational speed is independent of the target flow rate and the status.

[0082] Another example (e.g., example 15) relates to a previous example (e.g., one of the examples 1 to 14) or to any other example, wherein the rotary drive is a power take-off of a vehicle, the vehicle having mounted thereon the crane.

[0083] Another example (e.g., example 16) relates to a previous example (e.g., one of the examples 1 to 14) or to any other example, wherein the rotary drive is an electric rotary drive on a vehicle, the vehicle having mounted thereon the crane.

[0084] An example (e.g., example 17) relates to a vehicle having mounted thereon a crane. The vehicle comprises the apparatus according to a previous example (e.g., one of the examples 1 to 16) or to any other example. Control circuitry on the vehicle is configured to control the rotary drive based on the control data. The crane comprises at least one of one or more hydraulic cylinders and one or more slewing drives coupled to the displacement pump and drivable by the hydraulic fluid.

[0085] Another example (e.g., example 18) relates to a previous example (e.g., example 17) or to any other example, wherein the at least one of the one or more hydraulic cylinders of the crane and an outrigger of the crane.

[0086] Another example (e.g., example 19) relates to a previous example (e.g., one of the examples 17 or 18) or to any other example, wherein the crane is a loader crane.

[0087] An example (e.g., example 20) relates to a method for determining a target rotational speed for a rotary drive. The method comprises receiving first input data indicating a target flow rate of hydraulic fluid to be provided by a displacement pump of a crane. The displacement pump is driven by the rotary drive. The rotary drive is external to the crane. The method further comprises receiving second input data indicating a user input. The user input indicates which of a plurality of predefined modes is to be used for determining the target rotational speed. Additionally, the method comprises receiving third input data indicating the status of the rotary drive or a drive system driving the rotary drive. The method comprises determining the target rotational speed based on the target flow rate and the status using the mode indicated by the user input. In addition, the method comprises outputting control data indicating the determined target rotational speed.

[0088] Another example (e.g., example 21) 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 20) or to any other example, when the program is executed on a processor or a programmable hardware.

[0089] Another example (e.g., example 22) relates to a program having a program code for performing the method according to a previous example (e.g., example 20) or to any other example, when the program is executed on a processor or a programmable hardware.

[0090] 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.

[0091] 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 machine-executable, 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), application-specific integrated circuits (ASICs), integrated circuits (ICs) or system-on-a-chip (SoCs) systems programmed to execute the steps of the methods described above.

[0092] 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 individual 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 substeps, -functions, -processes or -operations.

[0093] 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.

[0094] 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.

Examples

Embodiment Construction

[0013]Some 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.

[0014]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.

[0015]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 individua...

Field

[0001] The present disclosure relates to controlling rotary drives driving displacement pumps of cranes. In particular, examples of the present disclosure relate to an apparatus and a method for determining a target rotational speed for a rotary drive, and a vehicle comprising the apparatus.Background

[0002] Cranes, in particular loader cranes play a pivotal role in various industries, providing efficient lifting and handling capabilities. Various functions of a crane such as lifting, lowering, extending, retracting, rotating, and stabilizing use hydraulic power provided by a displacement pump of the crane.

[0003] The displacement pump of a crane is conventionally provided with a constant speed from a Power Take-Off (PTO) of a vehicle carrying the crane. This leads to high noise of the displacement pump as the constant speed of the PTO is quite high and is highly dependent on the original equipment manufacturer. Due to the constant speed, there are high losses in the displacement pump if the crane is not utilized to its maximum capacity. Furthermore, the performance of the crane is not optimized with conventional technology and there is a significant energy consumption for vehicles.

[0004] Hence, there may be a demand for improved driving of a displacement pump of a crane.Summary

[0005] This demand is met by an apparatus and a method for determining a target rotational speed for a rotary drive, a vehicle, a non-transitory machine-readable medium and a program in accordance with the independent claims. Advantageous embodiments are defined by the dependent claims.

[0006] According to a first aspect, the present disclosure provides an apparatus for determining a target rotational speed for a rotary drive. The apparatus comprises processing circuitry configured to receive first input data indicating a target flow rate of hydraulic fluid to be provided by a displacement pump of a crane. The displacement pump is driven by the rotary drive. The rotary drive is external to the crane. Further, the processing circuitry is configured to receive second input data indicating a user input. The user input indicates which of a plurality of predefined modes is to be used for determining the target rotational speed. The processing circuitry is additionally configured to receive third input data indicating the status of the rotary drive or a drive system driving the rotary drive. In addition, the processing circuitry is configured to determine the target rotational speed based on the target flow rate and the status according to the mode indicated by the user input. The processing circuitry is configured to output control data indicating the determined target rotational speed.

[0007] According to a second aspect, the present disclosure provides a vehicle having mounted thereon a crane. The vehicle comprises the apparatus according to the first aspect. Control circuitry on the vehicle is configured to control the rotary drive based on the control data. The crane comprises at least one of one or more hydraulic cylinders and one or more slewing drives coupled to the displacement pump and drivable by the hydraulic fluid.

[0008] According to a third aspect, the present disclosure provides a method for determining a target rotational speed for a rotary drive. The method comprises receiving first input data indicating a target flow rate of hydraulic fluid to be provided by a displacement pump of a crane. The displacement pump is driven by the rotary drive. The rotary drive is external to the crane. The method further comprises receiving second input data indicating a user input. The user input indicates which of a plurality of predefined modes is to be used for determining the target rotational speed. Additionally, the method comprises receiving third input data indicating the status of the rotary drive or a drive system driving the rotary drive. The method comprises determining the target rotational speed based on the target flow rate and the status using the mode indicated by the user input. In addition, the method comprises outputting control data indicating the determined target rotational speed.

[0009] According to a fourth 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 third aspect, when the program is executed on a processor or a programmable hardware.

[0010] According to a fifth aspect, the present disclosure provides a program having a program code for performing the method according to the third aspect, when the program is executed on a processor or a programmable hardware.

[0011] The rotary drive's rotational speed is controlled according to the requirements of the crane. Accordingly, an optimized hydraulic efficiency may be achieved. Operation of the displacement pump at an optimal flow rate may be achieved, reducing energy consumption and improving the efficiency of the crane's hydraulic system. This optimization may lead to cost savings and longer operational life for the equipment. Also there may be a significant noise reduction in the displacement pump as it may now operate at a lower speed when needed. In total, a performance optimization of the crane operation may be achieved. The inclusion of the user input to select the modes makes the proposed technology user-friendly. Operators can easily switch between modes tailored for specific operational requirements, enhancing usability and operational convenience. Furthermore, by enabling the selection from a plurality of predefined modes through the user input, the proposed technology provides flexibility in operation. This allows for customization according to specific tasks or conditions, improving the adaptability and efficiency of the crane.Brief description of the Figures

[0012] 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 Fig. 1 illustrates an example of an apparatus for determining a target rotational speed for a rotary drive; Fig. 2 illustrates an exemplary first mode for determining the target rotational speed; Fig. 3 illustrates an exemplary second mode for determining the target rotational speed; Fig. 4 illustrates an exemplary third mode for determining the target rotational speed; Fig. 5 illustrates a first exemplary data flow for determining the target rotational speed; Fig. 6 illustrates a second exemplary data flow for determining the target rotational speed; Fig. 7 illustrates an example of a vehicle; and Fig. 8 illustrates a flowchart of an example of a method for determining a target rotational speed for a rotary drive. Detailed Description

[0013] Some 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.

[0014] 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.

[0015] 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.

[0016] 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.

[0017] Fig. 1 schematically illustrates an apparatus 100 for determining a target rotational speed for a rotary drive (rotary actuator, rotary motion drive) 130. The rotary drive 130 is configured to produce (provide) controlled rotational movement. The target rotational speed denotes the desired or intended speed at which the rotary drive 130 should rotate. In other words, the target rotational speed refers to the desired or intended speed of the rotational movement to be provided by the rotary drive 130.

[0018] As schematically indicated in Fig. 1, a displacement pump 125 of a crane 120 is driven by the rotary drive 130 to provide hydraulic power. For example, the hydraulic power may be provided by means of a flow of hydraulic fluid caused (generated) by the displacement pump 125 when driven by the rotary drive 130. The hydraulic power provided by the displacement pump 125 is used by one or more consumers of the crane 120 (not illustrated in Fig. 1). The one or more consumers of the crane 120 are hydraulically coupled to the displacement pump 125. The displacement pump 125 and the one or more consumers of the crane 120 form a hydraulic system of the crane 120. For example, the one or more consumers may be one or more hydraulic cylinders and / or one or more slewing drives of the crane 120 for providing various functions of the crane 120 such as lifting, lowering, extending, retracting, rotating, and stabilizing. For reasons of simplicity, various elements of the crane 120 such as its one or more hydraulic cylinders, one or more slewing drives, (crane) base, boom (crane arm) or outriggers (crane legs) are not illustrated in Fig. 1.

[0019] The rotary drive 130 is external to the crane 120. In other words, the rotary drive 130 is not part of the crane 120. The rotary drive 130 may be any device or system capable of converting energy into mechanical rotation (rotational movement) in a controlled manner. For example, the rotary drive 130 may be an electric rotary drive comprising one or more electric motors for generating the rotational movement. According to examples of the present disclosure, the rotary drive 130 may be an electric rotary drive on a vehicle having mounted thereon (holding, carrying) the crane 120. In alternative examples, the rotary drive 130 may be a PTO driven by a drive system 140 (e.g., a combustion engine and optionally a gearbox). According to examples of the present disclosure, the rotary drive 130 may be a PTO of a vehicle having mounted thereon the crane 120. The vehicle may be a land vehicle (e.g., wheeled, tracked or railed) or a watercraft (e.g., a ship, a boat or a barge). For example, the crane 120 may be mounted to vehicle such as a truck for loading and unloading goods onto and from the vehicle. The rotary drive 130, in particular when implemented as electric rotary drive, may be detachably attached to the vehicle. In other examples, the rotary drive 130 may be fixedly attached to the vehicle. For reasons of clarity, the vehicle is not shown in Fig. 1.

[0020] In general, the crane 120 may be any type of crane using a displacement pump to provide hydraulic power. For example, the crane 120 may be a knuckle boom crane such as a loader crane for loading and unloading goods (loads). In other examples, the crane 120 may be the crane section of a mobile crane (with the vehicle being the mobile platform having mounted thereon the crane section).

[0021] The apparatus 100 may be part of the crane 120. According to examples, crane control circuitry (crane controller) 121 for controlling operation of the crane 120 may comprise the apparatus 100. The crane control circuitry 121 may, e.g., be coupled to the displacement pump 125 and control operation of the displacement pump 125 and optionally further elements of the crane 120. In other examples, the apparatus 100 and the crane control circuitry 121 may be separate elements of the crane. In alternative examples, the apparatus 100 may be external to the crane 120, i.e., not be part of the crane 120. For example, a computing cloud communicatively coupled to the crane 120 (e.g., via a wireless connection) may comprise or be the apparatus 100. In still other examples, the vehicle having mounted thereon the crane 120 may comprise the apparatus 100.

[0022] The apparatus 100 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 neuromorphic 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.

[0023] The processing circuitry 110 is configured to receive first input data 101. The first input data 101 indicate (are encoded with information about) a target flow rate of hydraulic fluid to be provided (delivered) by the displacement pump 125 of the crane 120. The target flow rate denotes the desired, demanded or intended flow rate at which hydraulic fluid should flow through the hydraulic system of the crane 120. The hydraulic fluid is to be supplied (pumped) at the target flow rate by the displacement pump 125. For example, the target flow rate may indicate how much volume (e.g., how many liters) of hydraulic fluid the displacement pump 125 should deliver per unit of time (e.g., per second or per minute). 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. The first input data 101 may, e.g., be received from the crane control circuitry 121. The crane control circuitry 121 controls the operation of the crane 120 and is, hence, aware of or able to calculate the required flow rate of hydraulic fluid for the (e.g., intended) operation of the crane 120. However, the present disclosure is not limited thereto. In other examples, the first input data 101 may be received from another entity (element, circuitry) of the crane 120.

[0024] Further, the processing circuitry 110 is configured to receive second input data 102 indicating a user input. The user input indicates which of a plurality of predefined (operational) modes is to be used for determining the target rotational speed. In other words, the user input specifies a particular mode among several (i.e., two or more) predefined options, and this chosen mode dictates how the target rotational speed is determined. The plurality of predefined modes are different from each other. In particular, the plurality of predefined modes differ from each other in the way the target rotational speed is determined based on the input data received by the processing circuitry 110. For example, the second input data 102 may be received from a remote control (not illustrated in Fig. 1). The remote control is a device for an operator (user) of the crane 120 for controlling the crane 120 from a distance. However, the present disclosure is not limited thereto. In other examples, the second input data 102 may be received from another entity such as an element or circuitry of the crane 120 (e.g., a Human-Machine Interface, HMI, of the crane 120), a mobile device (e.g., a mobile phone, a laptop-computer or a tablet-computer) of the operator of the crane 120 or a remote server.

[0025] The processing circuitry 110 is additionally configured to receive third input data 103 indicating the status of the rotary drive 130 or the drive system 140 driving the rotary drive 130. The status of the rotary drive 130 or the drive system 140 driving the rotary drive 130 refers to the operational condition, i.e., the current state or operational parameters of the rotary drive 130 or the drive system 140. For example, the status of the rotary drive 130 may be one or more of a current (present) rotational speed of the rotary drive 130, a current (present) load or utilization of the rotary drive 130 (e.g., a current torque utilization of the rotary drive 130). Similarly, the status of the drive system 140 driving the rotary drive 130 may be one or more of a current (present) rotational speed of the drive system 140, a current (present) load or utilization of the drive system 140 (e.g., a current torque utilization of the drive system 140).

[0026] The processing circuitry 110 is configured to determine the target rotational speed for the rotary drive 130 based on the target flow rate and the status according to the mode indicated by the user input. In other words, according to the mode selected by the user, the processing circuitry 110 determines the target rotational speed using the target flow rate indicated by the first input data 101 and the status indicated by the third input data 103 as input for the determination. The way the target rotational speed is determined by the processing circuitry 110 depends on the mode indicated by the user input.

[0027] The processing circuitry 110 is configured to output control data 105 indicating the determined target rotational speed. The control data 105 are for controlling the rotational speed of the rotary drive 130. The control data 105 may be output by the processing circuitry 110 to various entities - depending on the implementation of the rotary drive 130. For example, the processing circuitry 110 may be configured to output the control data 105 to the rotary drive 130 such that control circuitry of the rotary drive 130 may control the rotary drive 130 to adjust its rotational speed to the determined target rotational speed. In other examples, the processing circuitry 110 may be configured to output the control data 105 to control circuitry for the rotary drive 130 external to the rotary drive 130 such that the external control circuitry may control the rotary drive 130 to adjust its rotational speed to the determined target rotational speed. For example, if the rotary drive is an electric rotary drive on a vehicle having mounted thereon the crane 120, the processing circuitry 110 may be configured to output the control data 105 to the electric rotary drive such that control circuitry of the electric rotary drive may control the electric rotary drive to adjust its rotational speed to the determined target rotational speed. In case the rotary drive 130 is driven by the drive system 140, the processing circuitry 110 may be configured to output the control data 105 to the drive system 140 or control circuitry for the drive system 140 external to the drive system 140 such that the drive system 140 is controlled to adjust the driving of the rotary drive 130 such that the rotational speed of the rotary drive 130 is adjusted to the determined target rotational speed. For example, if the rotary drive 130 is a PTO of a vehicle having mounted thereon the crane 120, the processing circuitry 110 may be configured to output the control data 105 to the vehicle such that vehicle control circuitry of the vehicle may control the drive system 140 of the vehicle (e.g., a combustion engine of the vehicle) based on the control data 105.

[0028] The determination of the target rotational speed according to the proposed technology allows for flexible and precise control of the rotary drive 130's rotational speed based on varying operational requirements (indicated by the target flow rate and the status) and user preferences (determined by the mode indicated by the user input). The rotary drive 130's rotational speed is controlled according to the requirements of the crane 120, which are indicated by the target flow rate. Accordingly, an optimized hydraulic efficiency may be achieved. The apparatus 100 may, e.g., ensure that the displacement pump 125 operates at an optimal flow rate, reducing energy consumption and improving the efficiency of the hydraulic system. Compared to conventional approaches, there may be very low losses in the system even if the crane 120 is operated at a very low capacity. This may make the crane 120 highly energy efficient. This optimization may lead to cost savings and longer operational life for the equipment. Also there may be a significant noise reduction in the displacement pump 125 as it may now operate at a lower speed when needed. In total, a performance optimization of the crane operation may be achieved. The inclusion of the user input to select the modes makes the apparatus 100 user-friendly. The user input allows to customize the determination of the target rotational speed according to the needs or preferences of the user. Operators of the crane 120 may easily switch between modes tailored for specific operational requirements, enhancing usability and operational convenience. Furthermore, by enabling the selection from a plurality of predefined modes through user input, the apparatus 100 provides flexibility in operation. This allows for customization according to specific tasks or conditions, improving the adaptability and efficiency of the crane 120.

[0029] The first to third input data 103 as well as other input data to the processing circuitry 110 may be real-time data (i.e., data that is delivered / received immediately after collection / generation without significant delay). This may ensure that the target rotational speed can be dynamically adjusted. This real-time feedback loop helps in maintaining optimal performance and safety.

[0030] In the following, three exemplary modes for determining the target rotational speed based on the target flow rate and the status will be described in greater detail with reference to Figs. 2 to 4. However, it is to be noted that the present disclosure is not limited thereto. Other, additional or less modes may be used according to examples of the present disclosure.

[0031] Fig. 2 schematically illustrates an exemplary first mode 200 for determining the target rotational speed for the rotary drive 130. In the first mode 200, the processing circuitry 110 is configured to dynamically determine the target rotational speed based on at least the target flow rate indicated by the first input data 101 and the status indicated by the third input data 103. In other words, the processing circuitry 110 is configured to determine the target rotation speed substantially in real-time based on the inputs. For example, the processing circuitry 110 may be configured to determine the target rotational speed at a rate of 1 Hz or more, 10 Hz or more, 50 Hz or more, or 100 Hz or more in the first mode 200.

[0032] In the first mode 200, the determined target rotational speed for the rotary drive 130 dynamically follows the target flow rate, i.e., the demanded volume of hydraulic fluid per unit time, and the status of the rotary drive 130 or its driving system 140. This dynamic determination allows to adjust the rotational speed of the rotary drive 130 substantially in real-time to ensure optimal performance and adapt to changing conditions. The first mode 200 may be used for fast, dynamic operation of the crane 120.

[0033] The processing circuitry 110 may take into account further inputs for determining the target rotational speed for the rotary drive 130 in the first mode 200. For example, in the first mode 200, the processing circuitry 200 may be configured to determine the target rotational speed further based on data 201 indicating a displacement per revolution of the displacement pump 125 (e.g., liters of hydraulic fluid displaced per revolution). The data 201 may, e.g., be received from the control circuitry 121 or the displacement pump 125. The displacement pump 125's displacement per revolution may be constant or variable. Accordingly, the value indicated by the data 201 for the displacement per revolution of the displacement pump 125 may be a constant value or change over time. The displacement pump 125's displacement per revolution may, e.g., be measured via a corresponding sensor. In other examples, the data 201 may indicate the maximum (possible, supported) displacement per revolution of the displacement pump 125 (e.g., if the displacement pump 125's displacement per revolution is not measured). Knowing the displacement per revolution of the displacement pump 125 allows to more precisely estimate the flow rate of hydraulic fluid caused by the displacement pump 125 for the various possible rotational speeds of the rotary drive 130. Accordingly, the rotational speed required to achieve the target flow rate indicated by the first input data 101 may be determined more precisely.

[0034] Alternatively or additionally, the processing circuitry 110 may, in the first mode 200, be configured to determine the target rotational speed further based on data 202 indicating a predefined rotational speed offset for increasing the rotational speed of the rotary drive 130. The predefined rotational speed offset refers to a set value or adjustment factor that is used to increase the determined target rotational speed for the rotary drive 130 by a certain amount. For example, if the target rotational speed for the rotary drive 130 is, based on the target flow rate indicated by the first input data 101, the status indicated by the third input data 103 and optionally further inputs such as the data 201, determined to be X revolutions per unit time and the predefined rotational speed offset is Y revolutions per unit time, the resulting target rotational speed is Z = X + Y revolutions per time unit. In other examples, if an adjustment factor A ≥ 1 is used instead of the set value Y, the resulting target rotational speed is Z = X . A revolutions per time unit. The predefined rotational speed offset allows to add a safety margin to the target rotational speed for the rotary drive 130. Accordingly, too low rotational speeds of the rotary drive 130 may be avoided. As a consequence, unwanted limitation of the hydraulic system's and, hence, the crane 120's performance may be avoided. The data 202 may, e.g., be received from the control circuitry 121 or any other element or circuitry of the crane 120. For example, the predefined rotational speed offset may depend on the current application or use of the crane (e.g., lifting of a load, rotating of the boom relative to the crane base, changing a positioning of the crane arm, etc.). In other examples, the predefined rotational speed offset may be determined (set) by a user input at, e.g., the remote control.

[0035] The processing circuitry 110 may be configured to determine the target rotational speed in the first mode 200 using a predefined computational model. The computational model is a mathematical representation (e.g., a set of mathematical equations) for determining the target rotational speed for the rotary drive 130 taking into account the target flow rate indicated by the first input data 101, the status indicated by the third input data 103 and optionally further inputs such as one or more of the data 201 and 202. The computational model may use various signal and / or data processing operations such as signal / data addition, subtraction, multiplication, division, integration, derivation, filtering (e.g., discrete, continuous or both), delaying, etc. to determine the target rotational speed based on the various inputs to the processing circuitry 110.

[0036] An exemplary second mode 300 for determining the target rotational speed for the rotary drive 130 is illustrated in Fig. 3. Compared to the first mode 200, the target rotational speed for the rotary drive 130 is determined (e.g., raised or lowered) in a stepped manner in the second mode 300.

[0037] In the second mode 300, the processing circuitry 110 is configured to periodically determine an auxiliary value for the target rotational speed based on the target flow rate indicated by the first input data 101 and the status indicated by the third input data 103. In other words, the processing circuitry 110 is configured to determine the auxiliary value for the target rotational speed at regular time intervals, not continuously. For example, the processing circuitry 110 may be configured to determine the auxiliary value for the target rotational speed at a rate of 0.5 Hz or less, 0.25 Hz or less, or 0.1 Hz or less in the second mode 300.

[0038] The processing circuitry 100 may be configured to determine the auxiliary value for the target rotational speed in the second mode 300 using the predefined computational model used in the first mode 200 for determining the target rotational speed or another computational model. Furthermore, the processing circuitry 110 may take into account further inputs for determining the auxiliary value for the target rotational speed for the rotary drive 130 in the second mode 300 - analogously to what is described above for the determination of the target rotational speed in the first mode 200. For example, in the second mode 300, the processing circuitry 110 may be configured to determine the auxiliary value for the target rotational speed further based on at least one of the data 201 indicating the displacement per revolution of the displacement pump 125 and the data 202 indicating the predefined rotational speed offset for increasing the rotational speed of the rotary drive 130.

[0039] In the second mode 300, the processing circuitry 110 is further configured to compare the determined auxiliary value for the target rotational speed to a current value of the rotational speed of the rotary drive 130. For example, the processing circuitry 110 may be configured to receive data indicating the current value of the rotational speed of the rotary drive 130. This data may, e.g., be received from the rotary drive 130, the control circuitry for the rotary drive 130 external to the rotary drive 130, the drive system 140 or the control circuitry for the drive system 140 external to the drive system 140. However, the present disclosure is not limited thereto. For example the data indicating the current value of the rotational speed of the rotary drive 130 may be received from any other circuitry of a vehicle having mounted thereon the crane 120.

[0040] Based on the result of the comparison, the current value of the target rotational speed is changed or not. If the difference between the determined auxiliary value for the target rotational speed and the current value of the rotational speed satisfies a criterion, the processing circuitry 110 is configured to set the auxiliary value for the target rotational speed as the target rotational speed. The criterion may be manyfold. For example, the criterion may be that the absolute difference between the determined auxiliary value for the target rotational speed and the current value of the rotational speed is greater than a first threshold value (e.g., more than 50, 100, 150, 200 or 250 revolutions per minute). In alternative examples, the criterion may be that the relative difference between the determined auxiliary value for the target rotational speed and the current value of the rotational speed is greater than a second threshold value (e.g., 5 % or more, 10 % or more, 15 % or more, 20 % or more, or 25 % or more). However, the present disclosure is not limited to the aforementioned exemplary criteria. Any other suitable criterion may be used instead.

[0041] If the difference between the determined auxiliary value for the target rotational speed and the current value of the rotational speed does not satisfy the criterion, the processing circuitry 110 is further configured to set the current value of the rotational speed as the target rotational speed in the second mode 300. In other words, the current value of the target rotational speed is not changed by the processing circuitry 110 if the difference between the determined auxiliary value for the target rotational speed and the current value of the rotational speed does not satisfy the criterion.

[0042] In the second mode 300, the determined target rotational speed for the rotary drive 130 follows the target flow rate and the status of the rotary drive 130 or its driving system 140 step-wise. In other words, the determined target rotational speed for the rotary drive 130 is step-wise increased or decreased according to the target flow rate and the status of the rotary drive 130 or its driving system 140. Compared to the first mode 200, the step-wise adaptation of the target rotational speed of the second mode 300 requires less computational efforts but allows to achieve good performance and sufficient adaptation to changing conditions. Additionally, the noise in the displacement pump 125 may be further reduced compared to the first mode 200 as the change of the rotary drive 130's rotational speed is less dynamic. The second mode 300 may be used for slow, less dynamic operation of the crane 120.

[0043] Fig. 4 illustrates an exemplary third mode 400 for determining the target rotational speed for the rotary drive 130. In the third mode 400, the processing circuitry 110 is configured to constantly (permanently) determine a first predefined rotational speed to be the target rotational speed. The first predefined rotational speed is a constant rotational speed. The processing circuitry 110 may, e.g., be configured to read data 401 indicating the first predefined rotational speed from a memory coupled to the processing circuitry 110. In other examples, the processing circuitry 110 may be configured to receive the data 401 from the crane control circuitry 121 or any other entity (element, circuitry) of the crane 120. For example, the first predefined rotational speed may be predefined by a manufacturer of the crane 120 or a manufacturer of the displacement pump 125. In other examples, the first predefined rotational speed may be determined (set) by a user input at, e.g., the remote control. Accordingly, the data 401 may be received from the remote control. The first predefined rotational speed is independent of the target flow rate indicated by the first input data 101 and the status indicated by the third input data 103. Accordingly, the determined target rotational speed for the rotary drive 130 is independent of the target flow rate indicated by the first input data 101 and the status indicated by the third input data 103 in the third mode 400.

[0044] The third mode 400 allows to provide the crane 120 with constant hydraulic power sufficient for specific applications. As the rotary drive 130's rotational speed is not changed in the third mode 400, noise in the displacement pump 125 is constant. Furthermore, the third mode 400 requires only little computational efforts.

[0045] The specific operation of the crane 120 may further be considered when determining the target rotational speed for the rotary drive 130. This is exemplarily illustrated in Fig. 5 showing a data flow 500 in the processing circuitry 110 for determining the target rotational speed for the rotary drive 130.

[0046] In addition to the above described input data, the processing circuitry 110 may be configured to receive fourth input data 501. The fourth input data 501 indicates whether the crane 120 is driving a hydraulic cylinder or a slewing drive of (for) a crane arm (boom) with the hydraulic fluid provided by the displacement pump 125, or whether the crane 120 is driving a hydraulic cylinder of an outrigger with the hydraulic fluid provided by the displacement pump 125. For example, the processing circuitry 110 may be configured to receive the data 501 from the crane control circuitry 121 or any other entity (element, circuitry) of the crane 120.

[0047] The fourth input data 501 are analyzed by the processing circuitry 110 as indicated by block 510 in Fig. 5. If the fourth input data 501 indicate that the crane 120 is driving the hydraulic cylinder or the slewing drive of the crane arm with the hydraulic fluid, the processing circuitry 110 is configured to determine the target rotational speed based on the target flow rate indicated by the first input data 101 and the status indicated by the third input data according to the mode indicated by the user input of the second input data 102. For example, the processing circuitry 110 may determine the target rotational speed according to one of the modes described above. This is exemplarily illustrated by block 520 in Fig. 5. For example, the processing circuitry 110 may be configured to enable (activate) the processing represented by block 520 in Fig. 5 if the fourth input data 501 indicate that the crane 120 is driving the hydraulic cylinder or the slewing drive of the crane arm with the hydraulic fluid.

[0048] On the other hand, if the fourth input data 501 indicate that the crane 120 is driving the hydraulic cylinder of the outrigger with the hydraulic fluid, the processing circuitry 110 is configured to (e.g., constantly, permanently) determine a second predefined rotational speed to be the target rotational speed. For example, the processing circuitry 110 may be configured to constantly (permanently) determine the second predefined rotational speed to be the target rotational speed while the fourth input data 501 indicate that the crane 120 is driving the hydraulic cylinder of the outrigger with the hydraulic fluid. This is exemplarily illustrated by block 530 in Fig. 5. The second predefined rotational speed is a constant rotational speed. The processing circuitry 110 may, e.g., be configured to read data 502 indicating the first predefined rotational speed from a memory coupled to the processing circuitry 110. In other examples, the processing circuitry 110 may be configured to receive the data 502 from the crane control circuitry 121 or any other entity (element, circuitry) of the crane 120. For example, the second predefined rotational speed may be predefined by a manufacturer of the crane 120 or a manufacturer of the displacement pump 125. In other examples, the second predefined rotational speed may be determined (set) by a user input at, e.g., the remote control. Accordingly, the data 502 may be received from the remote control. The second predefined rotational speed is independent of the target flow rate indicated by the first input data 101 and the status indicated by the third input data 103. Accordingly, the determined target rotational speed for the rotary drive 130 is independent of the target flow rate indicated by the first input data 101 and the status indicated by the third input data 103. The second predefined rotational speed may be equal to or be different from the first predefined rotational speed.

[0049] A multiplexer (switch) 540 is illustrated in Fig. 5 to exemplarily illustrate that either the second predefined rotational speed or the rotational speed determined based on the target flow rate indicated by the first input data 101 and the status indicated by the third input data according to the mode indicated by the user input is output as the target rotational speed - depending on whether the fourth input data 501 indicate that the crane 120 is driving the hydraulic cylinder or the slewing drive of the crane arm (boom) with the hydraulic fluid, or whether the fourth input data 501 indicate that the crane 120 is driving the hydraulic cylinder of the outrigger with the hydraulic fluid. In Fig. 5, the switching behavior of the multiplexer (switch) 540 is controlled according to the fourth input data 501 provided by block 510.

[0050] The crane 120 has different hydraulic power demands depending on its operation. This is reflected in the data flow 500 by taking into account the fourth input data 501. If the hydraulic power is used to drive the hydraulic cylinder(s) of the crane 120's outrigger(s), a specific constant hydraulic power is desired (or required). By outputting the second predefined rotational speed as the target rotational speed, it may be ensured that the rotary drive 130 provides the desired (required) input power to the displacement pump. On the other hand, if the hydraulic power is used to drive the hydraulic cylinder(s) or the slewing drive(s) of the crane 120's crane arm, the above beneficial effects may be achieved by determining the target rotational speed based on the target flow rate indicated by the first input data 101 and the status indicated by the third input data according to the mode indicated by the user input.

[0051] Fig. 6 illustrates another exemplary data flow 600 summarizing the above described aspects for determining the target rotational speed for the rotary drive 130 and highlighting some further optional aspects of the proposed technology.

[0052] As described above, the first input data 101, the second input data 102 and the third input data 103 are received. The user input indicated by the second input data 102 is analyzed. This is illustrated by block 610 in Fig. 1. In the example of Fig. 6, the three exemplary modes 200, 300 and 400 for determining the target rotational speed are used. As indicated above, additional, less or different modes may be used. Depending on which of the predefined modes 200, 300 and 400 is indicated by the user input, the corresponding one of the models 200, 300 and 400 is enabled (activated) to determine the target rotational speed based on the target flow rate indicated by the first input data 101 and the status indicated by the third input data 103.

[0053] The output of the selected model is received at a block 620 for further processing. In the following, three exemplary modifications of the target rotational speed determined via one of the models 200, 300 and 400 are described. The exemplary modifications are represented by locks 625, 630 and 640 in Fig. 6. It is to be noted that each of these modifications is optional. One or more of the modifications may be omitted according to the examples of the present disclosure.

[0054] Block 625 represents an optional change rate limitation. The processing circuitry 110 may be configured to modify, prior to outputting the output data 105, the determined target rotational speed to comply with a maximum (allowed, supported) change rate of the rotary drive 130's rotational speed if the determined target rotational speed changes by more than the maximum change rate of the rotary drive 130's rotational speed. In other words, the change of the determined target rotational speed over time is limited. This allows to protect the displacement pump 125 from too high accelerations or decelerations, which might damage the displacement pump 125. The maximum change rate of the rotary drive 130's rotational speed may depend on the type (model) of the displacement pump 125.

[0055] Furthermore, as indicated by block 630 in Fig. 6, the processing circuitry 110 may be further configured to modify, prior to outputting the output data 105, the determined target rotational speed to comply with first minimum and maximum rotational speeds 631 and 632 related to (defined by) the rotary drive 130 if the determined target rotational speed is below the first minimum rotational speed 632 or above the first maximum rotational speed 631. For example, the determined target rotational speed may be limited to the first minimum rotational speed 632 if the determined target rotational speed is below the first minimum rotational speed 632. Analogously, the determined target rotational speed may be limited to the first maximum rotational speed 631 if the determined target rotational speed is above the first maximum rotational speed 631. This allows to protect the rotary drive 130 from too high or too low rotational speeds, which might damage the rotary drive 130. The first minimum and maximum rotational speeds 631 and 632 may depend on the type (model) of the rotary drive 130.

[0056] As indicated by block 640 in Fig. 6, the processing circuitry 110 may be further configured to modify, prior to outputting the output data 105, the determined target rotational speed to comply with second minimum and maximum rotational speeds 641 and 642 related to (defined by) the displacement pump 125 if the determined target rotational speed is below the second minimum rotational speed 642 or above the second maximum rotational speed 641. For example, the determined target rotational speed may be limited to the second minimum rotational speed 642 if the determined target rotational speed is below the second minimum rotational speed 642. Analogously, the determined target rotational speed may be limited to the second maximum rotational speed 641 if the determined target rotational speed is above the second maximum rotational speed 641. This allows to protect the displacement pump 125 from too high or too low rotational speeds, which might damage the displacement pump 125. The second minimum and maximum rotational speeds 641 and 642 may depend on the type (model) of the displacement pump 125.

[0057] As indicated by block 680 in Fig. 6, the processing circuitry 110 may further be configured to determine whether the target flow rate indicated by the first input data 101 is zero for more than a predefined period of time. For example, the processing circuitry 110 may use a counter-to-zero which starts counting to zero as soon as and for as long as the target flow rate indicated by the first input data 101 is zero. The time period it takes from counting to zero from the start value of the counter-to-zero is the predefined period of time.

[0058] The block 690 receives the determination result of the block 680 and controls the further processing of the determined target rotational speed by blocks 650 and 655. If the target flow rate of hydraulic fluid is zero for more than the predefined period of time, the block 690 controls the block 655 to forward a predefined value 691 for the target rotational speed to block 660. Else, the block 690 controls the block 655 to not forward the predefined value 691 to the block 660. In this case, the target rotational speed determined by one of the models 200, 300 and 400 and optionally modified by one of the blocks 625, 630 and 640 is forwarded to the block 660. The predefined value 691 for the target rotational speed may, e.g., be zero. Alternatively, the predefined value 691 may be a non-zero value. For example, the predefined value 691 may be 250 revolutions per minute or less, 200 revolutions per minute or less, 150 revolutions per minute or less, 100 revolutions per minute or less, or 50 revolutions per minute or less. In other words, if the target flow rate of hydraulic fluid is zero for more than the predefined period of time, the processing circuitry 110 may be configured to determine the target rotational speed to be the predefined value 691. Else, the processing circuitry 110 may be configured to determine the target rotational speed based on the target flow rate indicated by the first input data 101 and the status indicated by the third input data 103 according to the mode indicated by the user input. As discussed above, the target flow rate indicated by the first input data 101 describes the crane 120's demand for hydraulic power. If the target flow rate indicated by the first input data 101 is zero for a longer period of time, the crane 120 is likely not operated. Accordingly, by determining the target rotational speed to be the predefined value 691, the rotational speed of the rotary drive 130 may be adapted to the crane 120's low demand for hydraulic power. This may allow to reduce the energy consumption and improve the efficiency of the crane 120's hydraulic system. This optimization may lead to cost savings. Also there may be a significant noise reduction in the displacement pump as it may now operate at a lower speed.

[0059] The adaptation of the target rotational speed depending on whether the crane 120 is driving the hydraulic cylinder or the slewing drive of the crane arm (boom) with the hydraulic fluid provided by the displacement pump 125, or whether the crane 120 is driving the hydraulic cylinder of the outrigger with the hydraulic fluid provided by the displacement pump 125, is illustrated in Fig. 6 by block 670. The block 670 receives the fourth input data 501 and analyzes them as described above. If the fourth input data 501 indicate that the crane 120 is driving the hydraulic cylinder or the slewing drive of the crane arm with the hydraulic fluid, the target rotational speed determined by one of the models 200, 300 and 400 and optionally modified by one of the blocks 625, 630 and 640 is output as the output data 105.

[0060] On the other hand, if the fourth input data 501 indicate that the crane 120 is driving the hydraulic cylinder of the outrigger with the hydraulic fluid, the second predefined rotational speed is determined to be the target rotational speed and output as the output data 105.

[0061] Fig. 7 illustrates a truck as an exemplary vehicle 700 having mounted thereon (holding) a loader crane (knuckle boom crane) as an exemplary crane 720. In the example of Fig. 7, the crane 720 comprises hydraulic cylinders 721, 722 and 723 for driving (moving) the crane arm 724 of the crane 720. Additionally, the crane 720 comprises hydraulic cylinders 725 for driving (moving) the outriggers 726. Further illustrated in Fig. 7 is the slewing drive 728 for rotating the crane arm 724 relative to the base 727 of the crane. The hydraulic cylinders and the slewing drive(s) are hydraulically coupled to the displacement pump 125 of the crane 720 and form the hydraulic system of the vehicle 700. The hydraulic cylinders and the slewing drive(s) are drivable (driven) by the displacement pump 125 of the crane 720. The displacement pump 125 of the crane 720 is driven by the rotary drive 130 on the vehicle 700.

[0062] The vehicle 700 further comprises the apparatus 100 according to the present disclosure for determining a target rotational speed for the rotary drive 130. As described above, the rotary drive 130 may, e.g., be a PTO of the vehicle 700. For example, the PTO may be driven by a combustion engine and optionally a gearbox of the vehicle 700. In alternative examples, the rotary drive 130 may be an electric rotary drive on the vehicle 700. For reasons of simplicity, the rotary drive 130 is illustrated schematically in Fig. 7.

[0063] Control circuitry 710 on the vehicle 710 is configured to control the rotary drive 130 based on the control data 105 output by the apparatus 100. As described above, the control circuitry 710 may be manifold depending on the type of rotary drive.

[0064] Compared to conventional vehicles, the vehicle 700 may achieve an optimized hydraulic efficiency, reduced energy consumption, improved noise emission and enhanced usability and operational convenience.

[0065] For further highlighting the driving of displacement pumps of cranes described above, Fig. 8 illustrates a flowchart of a method 800 for determining a target rotational speed for a rotary drive. The method 800 comprises receiving 802 first input data indicating a target flow rate of hydraulic fluid to be provided by a displacement pump of a crane. The displacement pump is driven by the rotary drive. The rotary drive is external to the crane. The method 800 further comprises receiving 804 second input data indicating a user input. The user input indicates which of a plurality of predefined modes is to be used for determining the target rotational speed. Additionally, the method 800 comprises receiving 806 third input data indicating the status of the rotary drive or a drive system driving the rotary drive. The method 800 comprises determining 808 the target rotational speed based on the target flow rate and the status using the mode indicated by the user input. In addition, the method 800 comprises outputting 810 control data indicating the determined target rotational speed.

[0066] Analogously to what is described above, the method 800 may allow performance optimization of the crane operation, noise reduction, enhancement of usability and operational convenience as well as flexibility in operation.

[0067] More details and aspects of the method 800 are explained in connection with the proposed technique or one or more examples described above (e.g., Fig. 1 or Fig. 7). The method 800 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.

[0068] The examples described herein may be summarized as follows: An example (e.g., example 1) relates to an apparatus for determining a target rotational speed for a rotary drive. The apparatus comprises processing circuitry configured to receive first input data indicating a target flow rate of hydraulic fluid to be provided by a displacement pump of a crane. The displacement pump is driven by the rotary drive. The rotary drive is external to the crane. Further, the processing circuitry is configured to receive second input data indicating a user input. The user input indicates which of a plurality of predefined modes is to be used for determining the target rotational speed. The processing circuitry is additionally configured to receive third input data indicating the status of the rotary drive or a drive system driving the rotary drive. In addition, the processing circuitry is configured to determine the target rotational speed based on the target flow rate and the status according to the mode indicated by the user input. The processing circuitry is configured to output control data indicating the determined target rotational speed.

[0069] Another example (e.g., example 2) relates to a previous example (e.g., example 1) or to any other example, wherein the plurality of predefined modes comprise a first mode in which the processing circuitry is configured to dynamically determine the target rotational speed based on the target flow rate and the status.

[0070] Another example (e.g., example 3) relates to a previous example (e.g., example 2) or to any other example, wherein the processing circuitry is configured to determine the target rotational speed at a rate of 10 Hz or more in the first mode.

[0071] 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, in the first mode, the processing circuitry is configured to determine the target rotational speed further based on at least one of data indicating a displacement per revolution of the displacement pump and data indicating a predefined rotational speed offset for increasing the rotational speed of the rotary drive.

[0072] Another example (e.g., example 5) relates to a previous example (e.g., one of the examples 1 to 4) or to any other example, wherein the plurality of predefined modes comprise a second mode in which the processing circuitry is configured to: periodically determine an auxiliary value for the target rotational speed based on the target flow rate and the status; compare the determined auxiliary value for the target rotational speed to a current value of the rotational speed of the rotary drive; and set the auxiliary value for the target rotational speed as the target rotational speed if the difference between the determined auxiliary value for the target rotational speed and the current value of the rotational speed satisfies a criterion.

[0073] Another example (e.g., example 6) relates to a previous example (e.g., example 5) or to any other example, wherein, in the second mode, the processing circuitry is further configured to set the current value of the rotational speed as the target rotational speed if the difference between the determined auxiliary value for the target rotational speed and the current value of the rotational speed does not satisfy the criterion.

[0074] Another example (e.g., example 7) relates to a previous example (e.g., one of the examples 5 or 6) or to any other example, wherein the processing circuitry is configured to determine the auxiliary value for the target rotational speed at a rate of 0.5 Hz or less in the second mode.

[0075] Another example (e.g., example 8) relates to a previous example (e.g., one of the examples 5 to 7) or to any other example, wherein, in the second mode, the processing circuitry is configured to determine the auxiliary value for the target rotational speed further based on at least one of data indicating a displacement per revolution of the displacement pump and data indicating a predefined rotational speed offset for increasing the rotational speed of the rotary drive.

[0076] Another example (e.g., example 9) relates to a previous example (e.g., one of the examples 1 to 8) or to any other example, wherein the plurality of predefined modes comprise a third mode in which the processing circuitry is configured to constantly determine a first predefined rotational speed to be the target rotational speed.

[0077] Another example (e.g., example 10) relates to a previous example (e.g., example 9) or to any other example, wherein the first predefined rotational speed is independent of the target flow rate and the status.

[0078] Another example (e.g., example 11) relates to a previous example (e.g., one of the examples 1 to 10) or to any other example, wherein the processing circuitry is further configured to: determine whether the target flow rate of hydraulic fluid indicated by the first input data is zero for more than a predefined period of time; if the target flow rate of hydraulic fluid is zero for more than the predefined period of time, determine the target rotational speed to be a predefined value; and else, determine the target rotational speed based on the target flow rate and the status according to the mode indicated by the user input.

[0079] 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 further configured to modify, prior to outputting the output data, the determined target rotational speed to comply with first minimum and maximum rotational speeds related to the rotary drive if the determined target rotational speed is below the first minimum rotational speed or above the first maximum rotational speed.

[0080] Another example (e.g., example 13) relates to a previous example (e.g., one of the examples 1 to 12) or to any other example, wherein the processing circuitry is further configured to modify, prior to outputting the output data, the determined target rotational speed to comply with second minimum and maximum rotational speeds related to the displacement pump if the determined target rotational speed is below the second minimum rotational speed or above the second maximum rotational speed.

[0081] Another example (e.g., example 14) relates to a previous example (e.g., one of the examples 1 to 13) or to any other example, wherein the processing circuitry is further configured to: receive fourth input data indicating whether the crane is driving a hydraulic cylinder or a slewing drive of a crane arm or an outrigger with the hydraulic fluid; if the fourth input data indicate that the crane is driving the hydraulic cylinder or the slewing drive of the crane arm with the hydraulic fluid, determine the target rotational speed based on the target flow rate and the status according to the mode indicated by the user input; and if the fourth input data indicate that the crane is driving the hydraulic cylinder of the outrigger with the hydraulic fluid, determine a second predefined rotational speed to be the target rotational speed, wherein the second predefined rotational speed is independent of the target flow rate and the status.

[0082] Another example (e.g., example 15) relates to a previous example (e.g., one of the examples 1 to 14) or to any other example, wherein the rotary drive is a power take-off of a vehicle, the vehicle having mounted thereon the crane.

[0083] Another example (e.g., example 16) relates to a previous example (e.g., one of the examples 1 to 14) or to any other example, wherein the rotary drive is an electric rotary drive on a vehicle, the vehicle having mounted thereon the crane.

[0084] An example (e.g., example 17) relates to a vehicle having mounted thereon a crane. The vehicle comprises the apparatus according to a previous example (e.g., one of the examples 1 to 16) or to any other example. Control circuitry on the vehicle is configured to control the rotary drive based on the control data. The crane comprises at least one of one or more hydraulic cylinders and one or more slewing drives coupled to the displacement pump and drivable by the hydraulic fluid.

[0085] Another example (e.g., example 18) relates to a previous example (e.g., example 17) or to any other example, wherein the at least one of the one or more hydraulic cylinders of the crane and an outrigger of the crane.

[0086] Another example (e.g., example 19) relates to a previous example (e.g., one of the examples 17 or 18) or to any other example, wherein the crane is a loader crane.

[0087] An example (e.g., example 20) relates to a method for determining a target rotational speed for a rotary drive. The method comprises receiving first input data indicating a target flow rate of hydraulic fluid to be provided by a displacement pump of a crane. The displacement pump is driven by the rotary drive. The rotary drive is external to the crane. The method further comprises receiving second input data indicating a user input. The user input indicates which of a plurality of predefined modes is to be used for determining the target rotational speed. Additionally, the method comprises receiving third input data indicating the status of the rotary drive or a drive system driving the rotary drive. The method comprises determining the target rotational speed based on the target flow rate and the status using the mode indicated by the user input. In addition, the method comprises outputting control data indicating the determined target rotational speed.

[0088] Another example (e.g., example 21) 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 20) or to any other example, when the program is executed on a processor or a programmable hardware.

[0089] Another example (e.g., example 22) relates to a program having a program code for performing the method according to a previous example (e.g., example 20) or to any other example, when the program is executed on a processor or a programmable hardware.

[0090] 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.

[0091] 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 machine-executable, 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), application-specific integrated circuits (ASICs), integrated circuits (ICs) or system-on-a-chip (SoCs) systems programmed to execute the steps of the methods described above.

[0092] 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 individual 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 substeps, -functions, -processes or -operations.

[0093] 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.

[0094] 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.

Examples

Embodiment Construction

[0013]Some 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.

[0014]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.

[0015]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 individua...

Claims

1. An apparatus (100) for determining a target rotational speed for a rotary drive (130), the apparatus (100) comprising processing circuitry (110) configured to: receive first input data (101) indicating a target flow rate of hydraulic fluid to be provided by a displacement pump (125) of a crane (120), wherein the displacement pump (125) is driven by the rotary drive (130), and wherein the rotary drive (130) is external to the crane (120); receive second input data (102) indicating a user input, wherein the user input indicates which of a plurality of predefined modes is to be used for determining the target rotational speed; receive third input data (103) indicating the status of the rotary drive (130) or a drive system (140) driving the rotary drive (130); determine the target rotational speed based on the target flow rate and the status according to the mode indicated by the user input; and output control data (105) indicating the determined target rotational speed.

2. The apparatus (100) of claim 1, wherein the plurality of predefined modes comprise a first mode in which the processing circuitry (110) is configured to dynamically determine the target rotational speed based on the target flow rate and the status.

3. The apparatus (100) of claim 2, wherein the processing circuitry (110) is configured to determine the target rotational speed at a rate of 10 Hz or more in the first mode.

4. The apparatus (100) of claim 2 or claim 3, wherein, in the first mode, the processing circuitry (110) is configured to determine the target rotational speed further based on at least one of data indicating a displacement per revolution of the displacement pump (125) and data indicating a predefined rotational speed offset for increasing the rotational speed of the rotary drive (130).

5. The apparatus (100) of any one of claims 1 to 4, wherein the plurality of predefined modes comprise a second mode in which the processing circuitry (110) is configured to: periodically determine an auxiliary value for the target rotational speed based on the target flow rate and the status; compare the determined auxiliary value for the target rotational speed to a current value of the rotational speed of the rotary drive (130); and set the auxiliary value for the target rotational speed as the target rotational speed if the difference between the determined auxiliary value for the target rotational speed and the current value of the rotational speed satisfies a criterion.

6. The apparatus (100) of claim 5, wherein, in the second mode, the processing circuitry (110) is further configured to set the current value of the rotational speed as the target rotational speed if the difference between the determined auxiliary value for the target rotational speed and the current value of the rotational speed does not satisfy the criterion.

7. The apparatus (100) of claim 5 or claim 6, wherein the processing circuitry (110) is configured to determine the auxiliary value for the target rotational speed at a rate of 0.5 Hz or less in the second mode.

8. The apparatus (100) of any one of claims 5 to 7, wherein, in the second mode, the processing circuitry (110) is configured to determine the auxiliary value for the target rotational speed further based on at least one of data indicating a displacement per revolution of the displacement pump (125) and data indicating a predefined rotational speed offset for increasing the rotational speed of the rotary drive (130).

9. The apparatus (100) of any one of claims 1 to 8, wherein the plurality of predefined modes comprise a third mode in which the processing circuitry (110) is configured to constantly determine a first predefined rotational speed to be the target rotational speed.

10. The apparatus (100) of claim 9, wherein the first predefined rotational speed is independent of the target flow rate and the status.

11. The apparatus (100) of any one of claims 1 to 10, wherein the processing circuitry (110) is further configured to: determine whether the target flow rate of hydraulic fluid indicated by the first input data (101) is zero for more than a predefined period of time; if the target flow rate of hydraulic fluid is zero for more than the predefined period of time, determine the target rotational speed to be a predefined value; and else, determine the target rotational speed based on the target flow rate and the status according to the mode indicated by the user input.

12. The apparatus (100) of any one of claims 1 to 11, wherein the processing circuitry (110) is further configured to modify, prior to outputting the output data, the determined target rotational speed to comply with first minimum and maximum rotational speeds related to the rotary drive (130) if the determined target rotational speed is below the first minimum rotational speed or above the first maximum rotational speed.

13. The apparatus (100) of any one of claims 1 to 12, wherein the processing circuitry (110) is further configured to modify, prior to outputting the output data, the determined target rotational speed to comply with second minimum and maximum rotational speeds related to the displacement pump (125) if the determined target rotational speed is below the second minimum rotational speed or above the second maximum rotational speed.

14. The apparatus (100) of any one of claims 1 to 13, wherein the processing circuitry (110) is further configured to: receive fourth input data (501) indicating whether the crane (120) is driving a hydraulic cylinder or a slewing drive of a crane (120) arm or an outrigger with the hydraulic fluid; if the fourth input data (501) indicate that the crane (120) is driving the hydraulic cylinder or the slewing drive of the crane (120) arm with the hydraulic fluid, determine the target rotational speed based on the target flow rate and the status according to the mode indicated by the user input; and if the fourth input data (501) indicate that the crane (120) is driving the hydraulic cylinder of the outrigger with the hydraulic fluid, determine a second predefined rotational speed to be the target rotational speed, wherein the second predefined rotational speed is independent of the target flow rate and the status.

15. A vehicle (700) having mounted thereon a crane (720), wherein the vehicle (700) comprises the apparatus (100) according to any one of claims 1 to 14, wherein control circuitry (710) on the vehicle (700) is configured to control the rotary drive (130) based on the control data (105), and wherein the crane (720) comprises at least one of one or more hydraulic cylinders (721, 722, 723, 725) and one or more slewing drives (728) coupled to the displacement pump (125) and drivable by the hydraulic fluid.

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