A tiltrotator control system and a method for controlling a hydraulic pressure generation system of a construction machine

Abstract

A tiltrotator control system (100) for controlling a hydraulic pressure generation system of a construction machine which hydraulic pressure generation system provides hydraulic fluid flow to a tiltrotator mounted at the construction machine. The tiltrotator control system (100) comprises a sensor arrangement (110) arranged to measure an incoming pressure value (PI) of hydraulic fluid pressurized by the hydraulic pressure generation system (210) which hydraulic fluid is incoming to a hydraulic drive device (310) of a tiltrotator (300) mounted on the construction machine (200). The sensor arrangement is further arranged to measure a load pressure value PL of hydraulic fluid pressurized by the hydraulic drive device (310) for driving at least rotational and / or tilting movements of the tiltrotator (300), and to transmit the incoming pressure value (PI) and the load pressure value (PL). The tiltrotator control system (100) further comprises a control device (120) arranged to receive the incoming pressure value (PI) and the load pressure value (PL) from the sensor arrangement (110), wherein the control device (120) comprises a selflearning system (122) which is arranged to produce, based on at least the incoming pressure value (PI) and the load pressure value (PL), a control value (a) and to output the control value (a) to control the hydraulic pressure generation system (210).

Description

Technical field

[0001] The present disclosure generally relates to a system controlling a hydraulic pump of a construction machine for a tiltrotator mounted on the construction machine.Technical background

[0002] Construction machine accessory rotators, such as tiltrotators, which allow an accessory of the construction machine to be used in a diverse manner, are known in the art. Such tiltrotators may provide rotation and tilt of the accessory, and thus also an improved manoeuvrability of the same. The movement of the tiltrotator is generally powered by a hydraulic pump of the construction machine that pressurizes hydraulic fluid, typically oil, to create a high-pressure hydraulic system. This pressurized hydraulic fluid is then directed to various hydraulic cylinders or hydraulic motors of the tiltrotator to drive its movement. Due to various parameters, such as the weight or friction of the material being excavated, the force encountered by the accessory, and therefore the tiltrotator, can vary. This variation causes the hydraulic system having to adjust accordingly. However, due to the high variability and unpredictability of the force encountered by the accessory, its magnitude is hard to predict. This makes it difficult to estimate how much the hydraulic pump should pressurize the hydraulic fluid to overcome the force encountered by the tiltrotator. In addition, the hydraulic pressure generating capacity of the hydraulic pump may vary depending on the model as well as individual characteristics due to manufacturing tolerances or wear. This may cause undesirable variations or uncertainties in the hydraulic pressure that is generated when controlling the hydraulic pump. Above problems makes it hard to accurately control the hydraulic pump such to allow the operator of the construction machine to manoeuvre the tiltrotator according to desire. Commonly, this is solved by applying an excessive amount of hydraulic pressure for overcoming uncertainties of encountered force or unexpected variations in the pressure generation capacity of the hydraulic pump. However, in addition to causing an excessive energy usage, the excessive hydraulic pressure may also cause unwanted wear on sub-components of the tiltrotator.

[0003] Accordingly, there is a need for improved construction machine accessory tiltrotators.Summary

[0004] It is an object of the present disclosure to mitigate, alleviate or eliminate one or more of the above-identified deficiencies in the art and disadvantages singly or in combination. The object is solved by the present disclosure according to the independent claims. Preferred embodiments are defined in the dependent claims. Further advantageous embodiments are described in the following.

[0005] According to a first aspect of the present disclosure, there is provided a tiltrotator control system for controlling a hydraulic pressure generation system of a construction machine which hydraulic pressure generation system provides hydraulic pressure to a tiltrotator mounted at the construction machine. The tiltrotator control system comprises a sensor arrangement arranged to measure an incoming pressure value of hydraulic fluid pressurized by a hydraulic pressure generation system of a construction machine which hydraulic fluid is incoming to a hydraulic drive device of a tiltrotator mounted on the construction machine. The sensor arrangement is further arranged to measure a load pressure value of hydraulic fluid pressurized by the hydraulic drive device for driving at least rotational and / or tilting movements of the tiltrotator, and to transmit the incoming pressure value and the load pressure value. The tiltrotator control system further comprises a control device arranged to receive the incoming pressure value and the load pressure value from the sensor arrangement. The control device comprises a self-learning system which is arranged to produce, based on at least the incoming pressure value and the load pressure value, a control value and to output the control value to control the hydraulic pressure generation system.

[0006] In general, the inventive concept is based on the realization that the tiltrotator control system, comprising a control device using a self-learning system for controlling a hydraulic pressure generation system of a construction machine based on at least the incoming pressure value and the load pressure value, is enabled to adapt itself to efficiently control the hydraulic pressure generation system for reducing energy loss from excessive hydraulic power generation. By self-learning system it may be meant a system that can adjust and improve its behavior based on experience or changing conditions. Thanks to that the tiltrotator control system comprises a self-learning system, it may adapt such to accurately control the hydraulic pressure generation system despite of characteristic variations of said hydraulic pressure generation system. By hydraulic pressure generation system, it may be meant a system of a construction machine comprising a hydraulic pump that pressurizes hydraulic fluid that is utilized to operate the tiltrotator. The tiltrotator control system measuring the incoming pressure value representing the supplied hydraulic pressure from the hydraulic pump, and the load pressure value representing the load pressure for overcoming the force encountered by the tiltrotator, may efficiently control the hydraulic pressure generation system in response to the force encountered. For example, the tiltrotator control system may control the hydraulic pressure generation system to increase the supplied hydraulic power to ensure performance when the force encountered is unexpectedly high, or reduce the supplied hydraulic power to reduce excessive power generation when the force encountered is unexpectedly low. By supplied hydraulic power from the hydraulic pressure generation system it may be meant the hydraulic fluid pressure pressurized by the hydraulic pressure generation system at the inlet of the hydraulic drive device. Thanks to that the system is self-learning it is able to adjust and improve its behaviour to overcome characteristic variations of the hydraulic pressure generation system. The tiltrotator control system may advantageously control the hydraulic pressure generation system to achieve a target criterion by appropriately output the control value. The target criterion may for example be such that a pressure differential between the incoming pressure value and the load pressure value is according to a desired pressure differential target value. The better the control device outputs the control value, the better the hydraulic pressure generation system will generate hydraulic power to meet the target criterion. The incoming pressure value may represent an incoming pressure of hydraulic fluid which is pressurized by the hydraulic pressure generation system. The load pressure value may represent the load pressure at the outlet, which is hydraulic pressure that drives the at least one movement of the tiltrotator. The load pressure must overcome the force encountered by the tiltrotator and / or a connected accessory for driving the tiltrotator movement. By the connected accessory it may be meant an attachment or tool, attached to the tiltrotator, that may be used by a construction machine for various tasks, such as digging, lifting, and moving material. Using a sensor arrangement to measure the incoming pressure value and the load pressure value is advantageous for providing continuous real-time data.

[0007] According to an embodiment, the control device is arranged to additionally receive a first input value, and the self-learning system is arranged to produce the control value based on at least the incoming pressure value, the load pressure value, and the first input value. The first input value may advantageously represent a hydraulic fluid flow required to drive a desired movement of the tiltrotator functions. By tiltrotator functions it may be meant a rotational movement, a tilting movement, and / or a movement of the connected accessory. Thereby the tiltrotator control system is enabled to control the hydraulic pressure generation system to generate sufficient hydraulic fluid flow to drive the movement of the tiltrotator functions according to a desired speed of the movement. The first input value may advantageously be generated by the operator of the construction machine, for example by moving a joystick. Additionally, the tiltrotator control system and the hydraulic pressure generation system may have different hydraulic fluid flow characteristics and behaviour at different ranges of hydraulic fluid flow. Thereby, in order to better produce the control value, the self-learning system may advantageously produce the control value additionally based on the hydraulic fluid flow required to drive the desired movement of the tiltrotator functions. The better the self-learning system produces the control value, the better the hydraulic pressure generation system will generate hydraulic power to meet the target criterion.

[0008] According to an embodiment, the self-learning system comprises an adaptive algorithm and a memory, which adaptive algorithm is arranged to calculate the control value. Using the adaptive algorithm for calculating the control value is advantageous since it may continuously, over time, adapt and optimize itself to better calculate the control value to achieve the target criterion. The better the adaptive algorithm calculates the control value, the better the hydraulic pressure generation system will generate hydraulic power to meet the target criterion. The algorithm may for example, over time learn the behaviour and / or characteristics of the tiltrotator control system and the hydraulic pressure generation system to better calculate the control value to achieve the target criterion. By the self-learning system having a memory it may be meant that it has the ability to retain and utilize information from past experiences or interactions. This memory enables the adaptive algorithm to adapt its behaviour over time based on the historical data it has encountered. For example, when the tiltrotator control system is turned off and then turned back on, the adaptive algorithm remembers previous adaptions. The tiltrotator control system is arranged to work with a wide range construction machines, and therefore a wide range of different models of hydraulic pumps used in hydraulic pressure generation systems. The control device comprising the self-learning system comprising an adaptive algorithm is particularly advantageous since it may learn the individual behaviour and characteristics of each individual construction machine and hydraulic pressure generation system, and self-adapt to better calculate the control value. Additionally, an adaptive algorithm, is advantageously used for adapting to changes of hydraulic pressure generation system and / or tiltrotator characteristics that might occur over time.

[0009] According to an embodiment, the adaptive algorithm is arranged to adapt itself in response to receiving the incoming pressure value, the load pressure value, and the first input value. Thereby, the adaptive algorithm is able to optimize itself, for calculating the control value within specific ranges of the first input value against specific ranges of the load pressure value. This allows the adaptive algorithm to accurately predict the control value over a wide range of load pressure of the tiltrotator and at different hydraulic fluid flow rates.

[0010] According to an embodiment, during a current control cycle, the sensor arrangement is arranged to measure and transmit the incoming pressure value and the load pressure value. Further, the control device is arranged to receive the load pressure value, the incoming pressure value, and the first input value and to calculate and output the control value. Further, during a subsequent control cycle, the sensor arrangement is arranged to measure and transmit the incoming pressure value and the load pressure value, and the control device is arranged to receive the load pressure value, the incoming pressure value, and the first input value and to calculate and output the control value. This is advantageous for continuously in time, controlling the hydraulic pressure generation system in relation to the variable load pressure of the tiltrotator. Preferably, as long as the construction machine is operating, the tiltrotator control system is continuously re-measuring the incoming pressure value and the load pressure value. It is continuously re-receiving the first input value, and continuously re-calculating the control value. Additionally, the self-learning system may continuously self-adapt or optimize itself to more accurately produce the control value. The self-learning system may advantageously over time adapt such that measurements during a current control cycle no longer triggers the self-learning system to further adapt itself. This may indicate that the self-learning system produces the control value according to the target criterion. The tiltrotator control system may advantageously be arranged such to notice if, after a significant large amount of control cycles where the self-learning system hasn't been triggered to adapt, the measured incoming pressure value and / or the load pressure value suddenly triggers the self-learning system to adapt. The tiltrotator control system may further be arranged to realise that this might be a sign of that a sub-component or similar of the tiltrotator control system is broken.

[0011] According to an embodiment, the control device is arranged to receive a second input value, wherein the control device is arranged to, based on the second input value, switch between at least a first user mode and a second user mode for calculating the control value. This is advantageous for enabling that the control device may use the first user mode to output the control value to achieve a first target criterion and the second user mode to output the control value to achieve a second target criterion. The first and second target criterion may define different levels of energy efficiency, comfort or responsiveness of the tiltrotator.

[0012] Alternatively, the second input value may describe a desired behaviour of the tiltrotator or an exterior environment that affects the load pressure of the tiltrotator.

[0013] According to an embodiment, the second input value represents that a pressure differential between the incoming pressure value and the load pressure value is according to a predetermined pressure differential target value. The second input value may advantageously describe the predetermined pressure differential target value. For example, the second input value may be settable to one or the other of two values, representing a relatively low predetermined pressure differential target value or a relatively high predetermined pressure differential target value. The operator of the construction machine may be able transmit the second input value, for example by pushing a button, to choose between using the first user mode of the control device and the second user mode of the control device. The operator of the construction machine may thereby for example choose the first user mode of the control device for increasing energy efficiency, and the second user mode of the control device for increasing performance or responsiveness of the tiltrotator.

[0014] According to an embodiment the control device is arranged to, based on an internal regulation value which is generated by the tiltrotator control system, switch between at least a first operating mode and a second operating mode for outputting the control value. The tiltrotator control system may thereby generate feedback to the control device and in response to the feedback switch between using the first operating mode and the second operating mode to output the control value.

[0015] According to an embodiment, the internal regulation value describes a gradient of the control value. The control device may thereby output the control value with respect to a gradient of the control value. For example, the control device may advantageously switch between the first operating mode and the second operating mode in response to if the load pressure increases or decreases, to better output the control value. This is advantageous for enabling that the control device when in the first operating mode may output the control value while taking in account that it increases, and when in the second operating mode the control device may output the control value taking in account that it decreases. Thereby, the control device may advantageously output the control value while compensating for hysteresis effects. Additionally the self-learning system may adapt such to better produce the control value when the gradient of the control value is increasing and / or decreasing.

[0016] According to an embodiment the sensor arrangement is arranged to measure the incoming pressure value at an inlet of the hydraulic drive device. This is advantageous for accurately measuring the hydraulic pressure which is generated by the hydraulic pressure generation system and transmitted to the hydraulic drive device.

[0017] According to an embodiment, the sensor arrangement is arranged to measure the load pressure value at an outlet of the hydraulic drive device (310). This is advantageous for accurately measuring the hydraulic pressure which drives at least one movement of the tiltrotator.

[0018] According to an embodiment the sensor arrangement comprises a first sensor arranged to measure the incoming pressure value, and a second sensor arranged to measure the load pressure value. Using at least two sensors is advantageous for an accurate measurement of the incoming pressure value and the load pressure value.

[0019] According to a second aspect of the disclosure, a tiltrotator is provided comprising the above-mentioned tiltrotator control system.

[0020] According to a third aspect of the present disclosure, there is provided a method for controlling a hydraulic pressure generation system of a construction machine for pressurizing hydraulic fluid for a tiltrotator which is mounted at the construction machine. The method comprises receiving an incoming pressure value of hydraulic fluid pressurized by a hydraulic pressure generation system of a construction machine which hydraulic fluid is incoming to a hydraulic drive device of a tiltrotator mounted on the construction machine, and receiving a load pressure value of hydraulic fluid pressurized by the hydraulic drive device for driving at least rotational and / or tilting movements of the tiltrotator. The method further comprises producing a control value based on at least the incoming pressure value and the load pressure value using a self-learning system, and outputting the control value to control the hydraulic pressure generation system.

[0021] According to an embodiment the step of receiving comprises additionally receiving a first input value and wherein said producing the control value being additionally based on at least the first input value.

[0022] A feature described in relation to one aspect may also be incorporated in other aspects, and the advantage of the feature is applicable to all aspects in which it is incorporated.

[0023] Other objectives, features and advantages of the present disclosure will appear from the following detailed disclosure, from the attached claims as well as from the drawings.

[0024] Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. Further, the use of terms "first", "second", and "third", and the like, herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. All references to "a / an / the [element, device, component, means, step, etc]" are to be interpreted openly as referring to at least one instance of said element, device, component, means, step, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated.Brief description of the drawings

[0025] The above, as well as additional objects, features and advantages of the present disclosure, will be better understood through the following illustrative and non-limiting detailed description of different embodiments of the present disclosure, with reference to the appended drawings, wherein: Fig. 1 schematically illustrates a tiltrotator control system according to an embodiment of the present disclosure and a construction machine with a mounted tiltrotator. Fig. 2 schematically illustrates a tiltrotator control system according to an embodiment of the present disclosure. Fig. 3 shows the structural set-up of the calculation parameters of an algorithm according to an embodiment of the present disclosure. Fig. 4 shows a schematic flow chart describing the adaptive algorithm according to an embodiment of the present disclosure. Fig. 5a-5b schematically illustrates a tiltrotator control system according to an embodiment of the present disclosure. Fig. 6a-6c each shows a control device comprised in a tiltrotator control system according to an embodiment of the present disclosure. Fig. 7 schematically illustrates a tiltrotator control system according to an embodiment of the present disclosure. Fig. 8 shows a schematic flow chart of a method according to an embodiment of the present disclosure. Detailed description

[0026] The present disclosure will now be described with reference to the attached figures. Features illustrated or described as part of one embodiment may be used with another embodiment to yield still a further embodiment. In the interest of clarity, not all features of an actual implementation are described in this specification. Various structures, systems and devices are schematically depicted in the drawings for purposes of explanation only and so as to not obscure the description with details that are well known to those skilled in the art. Nevertheless, the attached drawings are included to describe and explain illustrative examples of the disclosed subject matter.

[0027] The words and phrases used herein should be understood and interpreted to have a meaning consistent with the understanding of those words and phrases by those skilled in the relevant art. No special definition of a term or phrase, i.e., a definition that is different from the ordinary and customary meaning as understood by those skilled in the art, is intended to be implied by consistent usage of the term or phrase herein. To the extent that a term or phrase is intended to have a special meaning, i.e., a meaning other than that understood by skilled artisans, such a special definition will be expressly set forth in the specification in a definitional manner that directly and unequivocally provides the special definition for the term or phrase.

[0028] With refence to Fig. 1, according to a first aspect of the present disclosure, there is provided a tiltrotator control system 100 for controlling a hydraulic pressure generation system of a construction machine which hydraulic pressure generation system provides hydraulic fluid flow to a tiltrotator mounted at the construction machine. The tiltrotator control system 100 comprises a sensor arrangement 110 arranged to measure an incoming pressure value P I of hydraulic fluid pressurized by the hydraulic pressure generation system 210 which hydraulic fluid is incoming to a hydraulic drive device 310 of a tiltrotator 300 mounted on the construction machine 200. The sensor arrangement is further arranged to measure a load pressure value P L of hydraulic fluid pressurized by the hydraulic drive device 310 for driving at least rotational and / or tilting movements of the tiltrotator 300, and to transmit the incoming pressure value P I and the load pressure value P L . The tiltrotator control system 100 further comprises a control device 120 arranged to receive the incoming pressure value P I and the load pressure value P L from the sensor arrangement 110, wherein the control device 120 comprises a self-learning system 122 which is arranged to produce, based on at least the incoming pressure value P I and the load pressure value P L , a control value α and to output the control value α to control the hydraulic pressure generation system 210. The construction machine 200 may refer to a heavy-duty vehicle designed for executing construction tasks, for example ones involving earthwork operations, such as digging, lifting, and moving material. The hydraulic pressure generation system 210 may be located at the construction machine 200 and arranged to convert mechanical energy into hydraulic power, enabling the tiltrotator 300 to move, and, by using a connected accessory 320, perform various tasks such as digging, lifting, and moving material. The hydraulic pressure generation system 210 comprises a hydraulic pump. The connected accessory 320 may be a bucket for digging and excavating, an integrated grab, a grapple, or a sweeper. The hydraulic pressure generation system 210 is arranged to generate hydraulic power by pressurizing hydraulic fluid. The hydraulic pressure generation system 210 is arranged to generate hydraulic power to pressurize hydraulic fluid at the inlet 312 of the hydraulic drive device 310. The hydraulic pressure generation system 210 is fluidly connected to the inlet 312 via a fluid flow path 220. The fluid flow path 220 may be a hose. The tiltrotator control system 100 may be arranged to be partly mounted on the tiltrotator 300 and to be partly mounted on the construction machine 200. Alternatively, it may be arranged to be mounted in its entirety on the tiltrotator 300. Alternatively, it may be arranged to be partly, or entirely, mounted on the construction machine 200 and connected to the tiltrotator 300. The hydraulic drive device 310 may be arranged to drive multiple movements of the tiltrotator 300, such as rotation, tilt, and extra functions. In that case the load pressure that must be overcome by the incoming pressure may be defined as the highest of the multiple hydraulic pressure levels required to drive the multiple movements of the tiltrotator 300. Additionally, the hydraulic drive device 310 may drive the movement of one or more connected accessories 320. In that case, the load pressure overcome by the tiltrotator 300 may be the highest hydraulic pressure of the functions driving the movement of the tiltrotator and the movement of the one or more tiltrotator accessories. The hydraulic drive device 310 may be a hydraulic manifold, adapted to control hydraulic fluid flow to one or more tiltrotator drive units (not shown). An example of a tiltrotator drive unit may be a hydraulic motor driving rotation of the tiltrotator 300. Another example of a tiltrotator drive unit may be a hydraulic cylinder generating tilt movement of the tiltrotator 300. Additionally, a tiltrotator drive unit may drive an additional movement of the tiltrotator or the connected accessory 320. As shown in Fig. 2, in the exemplified embodiment, the inlet 312 is located inside the hydraulic drive device 310 extending between an first inlet port 312a and a second inlet port 312b. The first inlet port 312a is located at an exterior surface of the hydraulic drive device 310. The second inlet port 312b is fluidly connected to a control portion 316 of the hydraulic drive device 310. The outlet 314 is located inside the hydraulic drive device 310 extending between a first outlet port 314a and a second outlet port 314b. The first outlet port 314a is fluidly connected to the control portion 316 of the hydraulic drive device 310. The second outlet port 314b is located at an exterior surface of the hydraulic drive device 310. The hydraulic drive device 310 is arranged to operate by receiving pressurized hydraulic fluid at the inlet 312 and to utilize the control portion 316 to deliver an output pressure to the at least one tiltrotator drive unit. The sensor arrangement 110 is arranged to measure the incoming pressure value P I , representing the hydraulic fluid pressure generated by the hydraulic pressure generation system 210. According to an embodiment, as shown in Fig. 2, the sensor arrangement 110 is arranged to measure the incoming pressure value P I at the inlet 312 of the hydraulic drive device 310. Alternatively, the sensor arrangement 110 may be arranged to measure the incoming pressure value P I at the fluid flow path 220. Further, the sensor arrangement 110 is arranged to measure the load pressure value P L , representing the hydraulic fluid pressure at the outlet 314. The load pressure P L is the pressure defining the resistance of the movement of the tiltrotator 300.. If the hydraulic drive device 310 is connected to multiple tiltrotator drive units, the load pressure value P L may represent the highest of the different load pressures that drive the multiple motions. The sensor arrangement 110 may transmit the incoming pressure value P I and the load pressure value P L to the control device 120 via a cable or wirelessly. The control device 120 is a component comprising means to receive, process and transmit information. The control device 120 may be connected to the sensor arrangement 110 via cables for receiving the incoming pressure value P I and the load pressure value P L . Alternatively, the incoming pressure value P I and the load pressure value P L may be wirelessly transmitted from the sensor arrangement 110 to the control device 120. The control device 120 is arranged to output the control value α to control the hydraulic pressure generation system 210. The control device may output the control value α directly to the hydraulic pressure generation system 210 to control the hydraulic pressure generation system 210. Alternatively, the control device 120 may output the control value α to a construction machine control system arranged to control the hydraulic pressure generation system 210. The control device 120 may be arranged to transmit the control value α by cables. Alternatively, the control device 120 may be arranged to wirelessly transmit the control value α. In the exemplified embodiment, the control device 120 may output a control value α for controlling the hydraulic pressure generation system 210 to generate hydraulic power such to generate a pressure differential between the incoming pressure value P I and the load pressure value P L according to predetermined pressure differential target values.

[0029] The control device 120 comprises a self-learning system 122 arranged to produce the control value α based on the incoming pressure value P I and the load pressure value P L . The control device 120 may for example output the control value α such to control that the incoming pressure value P I exceeds the load pressure value P L by a predetermined pressure differential target value.

[0030] Defining the predetermined pressure differential target value to be relatively low may be advantageous for reducing, and preferably minimizing, excessive power generation from the hydraulic pressure generation system. By excessive power generation it may be meant that more power is generated than used. Reducing the excessive power generation is advantageous for reducing wear on sub-components of the tiltrotator control system as well as saving energy.

[0031] Defining the predetermined pressure differential target value to be relatively high may be advantageous for assuring that the tiltrotator drive unit is supplied with sufficient hydraulic pressure to tiltrotator functions with high performance and responsiveness.

[0032] The predetermined pressure differential target value may, by the operator of the construction machine 200, advantageously be defined according to a desired trade-off between the performance and energy efficiency of the tiltrotator 300.

[0033] Additionally, the control device 120 outputting a control value α to control that the pressure differential between the incoming pressure value P I and the load pressure value P L doesn't fall short of the predetermined pressure differential target value is advantageous for securing that the hydraulic drive device 310 contains an additional hydraulic pressure margin which may be used to overcome a sudden or unpredicted increase of force encountered by the tiltrotator 300. Alternatively, the control device 120 may output the control value α based on a target criterion other than the predetermined pressure differential target value. For example, the control device 120 may calculate and output the control value α to ensure high performance despite rapid changes of force encountered by the tiltrotator 300. Alternatively, the control device 120 may calculate and output the control value α to ensure high performance and responsiveness of the tiltrotator 300 during initial tiltrotator movements. In both examples the control device 120 may advantageously use the incoming pressure value P I and the load pressure value P L to control the hydraulic pressure generation system 210.

[0034] According to an embodiment, the control device 120 is arranged to additionally receive a first input value β1, and the self-learning system is arranged to produce the control value α based on at least the incoming pressure value P I , the load pressure value P L , and the first input value β1. In the exemplified embodiment, the first input value β1 represents a hydraulic fluid flow required to drive a desired movement of the tiltrotator functions. By tiltrotator functions it may be meant a rotational movement, a tilting movement, and / or a movement of a connected accessory function. The first input value β1 may be generated by an operator of the construction machine 200 controlling the tiltrotator 300, for example by means of a joystick. Alternatively, the first input value β1 may be generated by a movement control device controlling the movement of the tiltrotator 300. The movement control device may comprise intelligent software. The first input value β1 may be transmitted to the control device 120 by means of a cable. Alternatively, it may be wirelessly transmitted.

[0035] According to an embodiment, the self-learning system 122 comprises an adaptive algorithm 124 and a memory 126, which adaptive algorithm 124 is arranged to calculate the control value α. The self-learning system 122 comprises an adaptive algorithm 124 for calculating the control value α. The adaptive algorithm 124 may comprise multiple calculation parameters σ xy . The calculation parameters σ xy are based on the load pressure P L and the first input value β1. They are used by the adaptive algorithm 124 together with at least the incoming pressure value P I , the load pressure P L and the first input value β1 to calculate the control value α.

[0036] Fig. 3 shows a visualization of 16 calculation parameters σ xy of the adaptive algorithm 124. In Fig. 3 the horizontal axis represents an increase of load pressure value P L from left to right in a first load pressure range P L,1 , a second load pressure range P L,2 , a third load pressure range P L,3 and a fourth load pressure range P L,4 . The vertical axis represents an increase of the first input value β1 in an upward direction in a first input value range β1 1 , a second input value range β1 2 , a third input value range β1 3 and a fourth input value range β1 4 . Each calculation parameter σ xy may be associated with a specific range of the load pressure value P L and a specific range of the first input value β1. In Fig. 3 "x" and "y" are in increments of 1 between 1 and 4. The adaptive algorithm 124 may comprise any desired number of calculation parameters σ xy .

[0037] Each calculation parameter σ xy may be defined so that it can be used by the adaptive algorithm 124 within a certain range of the load pressure value P L and a certain range of the first input value β1, to calculate the control value α. For example, if the load pressure value P L is within the second load pressure range P L,2 and the first input value β1 is within the third input value range β1 3 , at least the calculation parameter σ 32 is used to calculate the control value α.

[0038] Alternatively, if the load pressure value P L is within the third load pressure value range P L ,3 and the first input value β1 is within the first input value range β1 1 at least the calculation parameter σ 13 is used to calculate the control value α. Since the tiltrotator control system 100 and the hydraulic pressure generation system 210 may have different hydraulic fluid flow characteristics within different hydraulic fluid flow ranges and load pressure ranges, the adaptive algorithm 124 may advantageously calculate the control value α with respect to the desired rate of hydraulic fluid flow, which rate is received from the first input value β1, and the load pressure value P L .

[0039] The adaptive algorithm 124 is a self-learning algorithm that self-adapts over time.

[0040] The adaptive algorithm 124 may be a computational method that adjusts it's behavior or adapts it's calculation parameters σ xy over time in response to input values. By input values it may be meant at least one of the incoming pressure value P I , the load pressure value P L , and the first input value β1. The adaptive algorithm 124 may adapt itself such to calculate the control value α to fulfill a target criterion. The self-learning system 122 comprises a memory 126 such to enable the adaptive algorithm 124 to store information from past control cycles, enabling the adaptive algorithm 124 to adjust its calculation parameters σ xy and / or behavior over time.

[0041] The target criterion may be to ensure that the pressure differential between the incoming pressure value P I and the load pressure value P L is according to the predetermined pressure differential target value. The predetermined pressure differential target value may be relatively low such to save energy. The predetermined pressure differential target value may be relatively high to ensure high performance and responsiveness of the tiltrotator 300. By high performance of the tiltrotator 300 it may be meant that the tiltrotator 300 is able to operate and move with the connected accessory 320 without disturbances. Alternatively, the target criterion may be to statistically over time minimize a deviation of the pressure differential between the incoming pressure value P I and the load pressure value P L from the predetermined pressure differential target value. Alternatively, the target criterion may be to ensure high performance despite rapid changes of the force encountered by the tiltrotator 300. Alternatively, the target criterion may be to ensure high comfort for the operator of the construction machine 200 during operation of the tiltrotator 300. By comfort it may be meant a pleasant and low fatiguing working environment for the machine's operator when operating the construction machine 200. Alternatively, the target criterion may be to ensure high responsiveness of the tiltrotator 300. By responsiveness it may be meant a quick and precise reaction of the movements of the tiltrotator 300 to the operator's input, facilitating efficient and accurate movements during digging, lifting, and other tasks. The adaptive algorithm 124 may for example learn a required level of pressure differential between the incoming pressure value P I and the load pressure value P L to achieve the target criterion of the tiltrotator 300, and may calculate the control value α accordingly. Alternatively, the target criterion may be a combination of multiple of the examples above.

[0042] According to an embodiment, the adaptive algorithm 124 is arranged to adapt itself in response to receiving the incoming pressure value P I , the load pressure value P L , and the first input value β1. Now with reference to Fig. 4. In the exemplified embodiment, the adaptive algorithm 124 adapts itself based on at least the incoming pressure value P I , the load pressure value P L , and the first input value β1. The adaptive algorithm 124 can from the incoming pressure value P I and the load pressure value P L , calculate a measured pressure differential ΔP meas . The measured pressure differential ΔP meas may be defined as being the pressure differential between the incoming pressure value P I and the load pressure value P L .

[0043] Further, the adaptive algorithm 124 can from the incoming pressure value P I , the load pressure value P L and the first input value β1 calculate a target pressure differential ΔP target . The adaptive algorithm 124 calculates the target pressure differential ΔP target using at least one of its calculation parameters σ xy .

[0044] The adaptive algorithm 124 thereafter calculates an error ε based on the measured pressure differential ΔP meas and the target pressure differential ΔP target . Thereafter the adaptive algorithm 124 may adapt itself such to reduce the error ε. In the exemplified embodiment, the adaptive algorithm 124 may adapt its calculation parameters σ xy in response to the error ε for minimizing it. The adaptive algorithm 124 may adapt one or multiple of its calculation parameters σ xy for minimizing the error ε. If the error ε is smaller than a set value, the adaptive algorithm 124 may not further adapt itself. The adaptive algorithm 124 may only adapt the one of its calculation parameters σ xy which is associated to the present range of the load pressure value P L and the first input value β1. Alternatively, the adaptive algorithm 124 may, for example by using interpolation, adapt multiple of its calculation parameters σ xy such that the adaptive algorithm 124 better calculates the control value α. The adaptive algorithm 124, can, after calculating the error ε and potentially adapting one or multiple of its calculation parameters σ xy , use the calculation parameters σ xy , to calculate the control value α.

[0045] The adaptive algorithm 124 may advantageously adapt its calculation parameters σ xy over time to better calculate the control value α.

[0046] Now with reference to Fig. 5a. According to an embodiment, during a current control cycle, the sensor arrangement 110 is arranged to measure and transmit the incoming pressure value P I (n) and the load pressure value P L (n). Further, the control device 120 is arranged to receive the load pressure value P L (n), the incoming pressure value P I (n), and the first input value β1(n) and to calculate and output the control value α(n). Further, as shown in Fig. 5b, during a subsequent control cycle, the sensor arrangement 110 is arranged to measure and transmit the incoming pressure value P I (n+1) and the load pressure value P L (n+1), and the control device 120 is arranged to receive the load pressure value P L (n+1), the incoming pressure value P I (n+1), and the first input value β1 (n+1) and to calculate and output the control value α(n+1). The subsequent control cycle may start before the current control cycle is finished. Alternatively, the subsequent control cycle may start subsequently in time after the current control cycle has finished. The time interval between the current control cycle and the subsequent control cycle is less than a second. The tiltrotator control system 100 may operate during n+1 number of control cycles where n may be any desired number. Additionally, the control device 120 may comprise the adaptive algorithm 124, which at each control cycle, based on the load pressure value P L (n), the incoming pressure value P I (n), and the first input value β1(n) adapts its calculation parameters σ xy to better calculate the control value α(n).

[0047] Now with reference to Fig. 6a, according to an embodiment, the control device 120 is arranged to receive a second input value β2, wherein the control device 120 is arranged to, based on the second input value β2, switch between at least a first user mode UM1 and a second user mode UM2 for calculating the control value α. In the exemplified embodiment, the self-learning system 122 comprises the adaptive algorithm 124, and the control device 120 uses a first set of calculation parameters σ xy,1 for the adaptive algorithm 124 to calculate the control value α when in the first user mode UM1, and a second set of calculation parameters σ xy,2 to calculate the control value α when in the second user mode UM2. Alternatively, the self-learning system 122 may use a first and a second adaptive algorithm in the first user mode UM1 and the second user mode UM2, respectively. In the first user mode UM1, the control device 120 is arranged to output a control value α to fulfil a first target criterion, and when in the second user mode UM2, the control device 120 is arranged to output the control value α to fulfil a second target criterion. The first target criterion may be to reduce the pressure differential between the incoming pressure value P I and the load pressure value P L to a relatively low predetermined pressure differential target value such to save energy. The second target criterion may be to increase the pressure differential between the incoming pressure value P I and the load pressure value P L to a relatively high predetermined pressure differential target value such to ensure high performance. Alternatively, different target criteria may be used. The control device 120 can, in response to the second input value β2, switch between the first user mode UM1 and the second user mode UM2 to fulfil the first target criterion or the second target criterion. The adaptive algorithm 124 can adapt the first set of calculation parameters σ xy,1 when the control device 122 is in the first user mode UM1 and adapt the second set of calculation parameters σ xy,2 when the control device 120 is in the second user mode UM2, such to better calculate the control value α. It is conceivable that the control device 120 is arranged to switch between more than two user modes in response to the second input value β2.

[0048] According to an embodiment, the second input value β2 represents that a pressure differential between the incoming pressure value (P I ) and the load pressure value (P L ) is according to a predetermined pressure differential target value. The second input value β2 may describe the predetermined pressure differential target value. In response of receiving the second input value β2, the control device 120 can switch to the first user mode UM1 or the second user mode UM2, to better output the control value α.

[0049] Now with reference to Fig. 6b, according to an embodiment the control device 120 is arranged to, based on an internal regulation value ω, which is generated by the tiltrotator control system 100, switch between at least a first operating mode OM1 and a second operating mode OM2 for outputting the control value α. In the exemplified embodiment, the control device 120 uses a third set of calculation parameters σ xy,3 for the adaptive algorithm 124 to calculate the control value α when in the first operating mode OM1 and a fourth set of calculation parameters σ xy,4 to calculate the control value α when in the second operating mode OM2. Alternatively, the control device 120 may use a third and a fourth adaptive algorithm in the first operating mode OM1 and the second operating mode OM2, respectively. The internal regulation value ω may be generated by the tilt rotator control system 100 and represent a value characterisation. By value characterisation it may be meant the gradient of at least one of the incoming pressure value P I , the load pressure value P L , the first input value β1, and the control value α. It is conceivable that the control device 120 is arranged to switch between more than two operating modes in response to the internal regulation value ω.

[0050] According to an embodiment, the internal regulation value ω describes a gradient of the control value α. The internal regulation value ω may be based on a historical control value α. Thereby, the internal regulation value ω may be used to determine if the control value α is increasing or decreasing. If the control value α is increasing the control device 120 may switch to the first operating mode OM1. If the control value α is decreasing the control device 120 may switch to the second operating mode OM2. The first operating mode OM1 is advantageously arranged to compensate for effects that may occur when the control value α increases. The second operating mode OM2 is advantageously arranged to compensate for effects that may occur when the control value α is reduced. The control device 120 may be arranged such to automatically detect the gradient of the control value α and switch between the first operating mode OM1 and the second operating mode OM2 in response the gradient of the control value α. With reference to Fig. 6c. According to an embodiment, the control device 120 is arranged to switch in between the first user mode UM1 and the second user mode UM2 in response to the second input value β2 and simultaneously switch between the first operating mode OM1 and the second operating mode OM2 in response to the internal regulation value ω. In the exemplified embodiment, when the control device 120 is switched to the first user mode UM1 it uses a first set of calculation parameters σ xy,11 or a third set of calculation parameters σ xy,12 for the adaptive algorithm 124 to calculate the control value α. When the control device 120 is switched to the second user mode UM2 it uses a second set of calculation parameters σ xy,21 or a fourth set of calculation parameters σ xy,22 for the adaptive algorithm 124 to calculate the control value α. When the control device 120 is switched to the first operating mode OM1 it uses the first set of calculation parameters σ xy,11 or the second set of calculation parameters σ xy,21 for the adaptive algorithm 124 to calculate the control value α. When the control device 120 is switched to the second operating mode OM2 it uses the third set of calculation parameters σ xy,12 or the fourth set of calculation parameters σ xy,22 for the adaptive algorithm 124 to calculate the control value α. For example, the control device 122, may in response to the second input value β2 and the internal regulation value ω switch to the first user mode UM1 and the second operating mode OM2 and thereby use the third set of calculation parameters σ xy,12 for the adaptive algorithm 124 to calculate the control value α. The control device 120 being able to simultaneously be in the first user mode UM1 or second user mode UM2 and the first operating mode OM1 or the second operating mode OM2 is advantageous for enabling the control device 120 to calculate a control value α in response of two behaviours or environmental circumstances. For example, the control device 120 may swich to first user mode UM1 such to have a relatively low predetermined pressure differential target value while also being the second operating mode OM2 for taking into account that the gradient of the control value α is increasing. The greatly enhances the versability of the tiltrotator control system. It is further conceivable that the control device 120 is arranged to receive additional input values controlling the control device 120 to be in additional user modes and / or additional internal regulation values controlling the control device 120 to be in additional operating modes.

[0051] With reference to Fig. 7. According to an embodiment the sensor arrangement 110 comprises a first sensor 112 arranged to measure the incoming pressure value P I at the inlet 312 of the hydraulic drive device 310, and a second sensor 114 arranged to measure the load pressure value P L at the outlet 314 of the hydraulic drive device 310. Each of the first sensor 112 and the second sensor 114 may be a pressure sensor arranged to measure pressure and to transmit the measured pressure value to the control device 120.

[0052] According to a second aspect of the disclosure, a tiltrotator 300 is provided comprising a tiltrotator control system 100 as described above. Fig. 8 schematically illustrates a method for controlling a hydraulic pressure generation system of a construction machine for pressurizing hydraulic fluid for a tiltrotator which is mounted at the construction machine. It is to be understood that the steps referred to in the following sections do not necessarily have to be performed in the disclosed order. The person skilled in the art readily understand which alternative order of steps are possible within the scope of the present disclosure. The method comprises receiving S1 an incoming pressure value P I of hydraulic fluid pressurized by the hydraulic pressure generation system 210 of a construction machine 200 which hydraulic fluid is incoming to a hydraulic drive device 310 of a tiltrotator 300 mounted on the construction machine 200, and receiving a load pressure value P L of hydraulic fluid pressurized by the hydraulic drive device 310 for driving at least rotational and / or tilting movements of the tiltrotator 300. The method further comprising producing S2 a control value α based on at least the incoming pressure value P I and the load pressure value P L using a self-learning system 122, and outputting S3 the control value α to control the hydraulic pressure generation system 210. The step of receiving S1 the incoming pressure value P I and the load pressure value P L may be performed using a sensor arrangement 110 measuring and transmitting the incoming pressure value P I and the load pressure value P L . The step of producing S2 a control value α is performed using the self-learning system 122, which can, based on the incoming pressure value P I and the load pressure value P L , produce the control value α to control the hydraulic pressure generation system 210. The self-learning system 122 is advantageously producing the control value α for controlling the hydraulic pressure generation system 210 to pressurize the hydraulic fluid in the fluid flow path 220 according to the target criterion. The self-learning system 122 may comprise an adaptive algorithm 124 and a memory.

[0053] The step of outputting S3 the control value α to control the hydraulic pressure generation system 210 may be performed by sending the control value α, via an electronic cable, or wirelessly, to the hydraulic pressure generation system 210. Alternatively, it may be done by sending the control value α, via an electronic cable, or wirelessly, to a construction machine control device arranged to control the hydraulic pressure generation system 210. The control value α may be used to generate an electrical signal to control the hydraulic pressure generation system 210.

[0054] According to an embodiment, the step of receiving S1 comprises additionally receiving a first input value β1 and said producing S2 a control value α is additionally based on at least the first input value β1. The first input value β1 may be received by the control device 120 such that the self-learning system 122 is able to produce the control value α at least based on the first input value β1.

[0055] It is to be mentioned that the above described method may be iterative and subsequently in time repeated. The purpose of the method is to continuously control the hydraulic pressure generation system 210 to pressurize hydraulic fluid at the inlet 312 of the hydraulic drive device 310 according to the target criterion. The method is preferably repeated as long as the construction machine 200 is operating. Thereby, the method allows for that the hydraulic pressure generation system 210 may, with a continuously improved efficiency, be controlled to generate a sufficient but not excessive amount of hydraulic power. The method may comprise one or more additional steps discussed in relation to the tiltrotator control system 100 according to the first aspect or any embodiments thereof.

[0056] The present disclosure has mainly been described above with reference to a few embodiments. However, as is readily appreciated by a person skilled in the art, other embodiments than the ones disclosed above are equally possible within the scope of the present disclosure, as defined by the appended claims.

[0057] Although features and elements are described above in particular combinations, each feature or element can be used alone without the other features and elements or in various combinations with or without other features and elements.

[0058] Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain features are recited in mutually different dependent claims does not indicate that a combination of these features cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.

Claims

1. A tiltrotator control system (100) for controlling a hydraulic pressure generation system of a construction machine which hydraulic pressure generation system provides hydraulic pressure to a tiltrotator mounted at the construction machine, wherein the tiltrotator control system (100) comprises: a sensor arrangement (110) arranged to measure an incoming pressure value (PI) of hydraulic fluid pressurized by a hydraulic pressure generation system (210) of a construction machine (200) which hydraulic fluid is incoming to a hydraulic drive device (310) of a tiltrotator (300) mounted on the construction machine (200), and to measure a load pressure value (PL) of hydraulic fluid pressurized by the hydraulic drive device (310) for driving at least rotational and / or tilting movements of the tiltrotator (300), and to transmit the incoming pressure value (PI) and the load pressure value (PL); and a control device (120) arranged to receive the incoming pressure value (PI) and the load pressure value (PL) from the sensor arrangement (110), wherein the control device (120) comprises a self-learning system (122) which is arranged to produce, based on at least the incoming pressure value (PI) and the load pressure value (PL), a control value (α) and to output the control value (α) to control the hydraulic pressure generation system (210).

2. The tiltrotator control system (100) according to any preceding claim, wherein the control device (120) is arranged to additionally receive a first input value (β1), and the self-learning system is arranged to produce the control value (α) based on at least the incoming pressure value (PI), the load pressure value (PL), and the first input value (β1).

3. The tiltrotator control system (100) according to any preceding claim wherein the self-learning system (122) comprises an adaptive algorithm (124) and a memory (126), which adaptive algorithm (124) is arranged to calculate the control value (α).

4. The tiltrotator control system (100) according to claim 3, wherein the adaptive algorithm (124) is arranged to adapt itself in response to receiving the incoming pressure value (PI), the load pressure value (PL), and the first input value (β1).

5. The tiltrotator control system (100) according to any of claims 2 to 4, wherein, during a current control cycle, the sensor arrangement (110) is arranged to measure and transmit the incoming pressure value (PI(n)) and the load pressure value (PL(n)), and the control device (120) is arranged to receive the load pressure value (PL(n)), the incoming pressure value (PI(n)), and the first input value (β1(n)) and to output the control value (α(n)), and wherein, during a subsequent control cycle, the sensor arrangement (110) is arranged to measure and transmit the incoming pressure value (PI(n+1)) and the load pressure value (PL(n+1)), and the control device (120) is arranged to receive the load pressure value (PL(n+1)), the incoming pressure value (PI(n+1)), and the first input value (β1(n+1)) and to output the control value (α(n+1)).

6. The tiltrotator control system (100) according to any preceding claim, wherein the control device (120) is arranged to receive a second input value (β2), wherein the control device (120) is arranged to, based on the second input value (β2), switch between at least a first user mode and a second user mode for calculating the control value (α).

7. The tiltrotator control system (100) according to claim 6, wherein the second input value (β2) represents that a pressure differential between the incoming pressure value (PI) and the load pressure value (PL) is according to a predetermined pressure differential target value.

8. The tiltrotator control system (100) according to any preceding claim, wherein the control device (120) is arranged to, based on an internal regulation value (ω) which is generated by the tiltrotator control system (100), switch between at least a first operating mode and a second operating mode for outputting the control value (α).

9. The tiltrotator control system (100) according to claim 8, wherein the internal regulation value (ω) describes a gradient of the control value (α).

10. The tiltrotator system (100) according to any preceding claim, wherein the sensor arrangement (110) is arranged to measure the incoming pressure value (PI) at an inlet (312) of the hydraulic drive device (310).

11. The tiltrotator system (100) according to any preceding claim, wherein the sensor arrangement (110) is arranged to measure the load pressure value (PL) at an outlet (314) of the hydraulic drive device (310).

12. The tiltrotator control system (100) according to any preceding claim, wherein the sensor arrangement (110) comprises a first sensor (112) arranged to measure the incoming pressure value (PI), and a second sensor (114) arranged to measure the load pressure value (PL).

13. A tiltrotator (300) comprising a tiltrotator control system (100) according to any preceding claim.

14. A method for controlling a hydraulic pressure generation system of a construction machine for pressurizing hydraulic fluid for a tiltrotator which is mounted at the construction machine, the method comprising: - receiving (S1): - an incoming pressure value (PI) of hydraulic fluid pressurized by a hydraulic pressure generation system (210) of a construction machine (200) which hydraulic fluid is incoming to a hydraulic drive device (310) of a tiltrotator (300) mounted on the construction machine (200); and - a load pressure value (PL) of hydraulic fluid pressurized by the hydraulic drive device (310) for driving at least rotational and / or tilting movements of the tiltrotator (300), - producing (S2) a control value (α) based on at least the incoming pressure value (PI) and the load pressure value (PL) using a self-learning system (122), and - outputting (S3) the control value (α) to control the hydraulic pressure generation system (210).

15. The method according to claim 14 comprising additionally receiving a first input value (β1), said producing (S2) the control value (α) being additionally based on at least the first input value (β1).

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