Operator guidance for using a fork carriage in combination with a tiltrotator

Abstract

The present invention relates to a control system for a work machine (6) for use with a fork carriage (2) having forks (16) in combination with a tiltrotator (1), the tiltrotator (1) including an upper part (4) arranged to be mounted on a work arm (3) of the work machine (6) and a lower part (5) rotatably and pivotably connected to the upper part (4), the control system being configured to be activated when the fork carriage (2) is mounted on the lower part (5) of the tiltrotator (1), and the control system is configured to adjust the position of the lower part relative to gravity. The tiltrotator (1) includes an inclinometer (11) disposed in the lower portion (5) of the tiltrotator (1) for sensing the orientation of the tiltrotator (1), and a display unit (12) disposed in the operator's cabin (7) of the work machine (6), the display unit (12) being configured to indicate the current orientation of the fork carriage (2) in the lower portion (5) of the tiltrotator (1) based on input from the inclinometer (11) to assist the operator in keeping the lower portion (5) and the attached fork carriage (2) level with respect to gravity.

Description

[Technical Field]

[0001] The present invention relates to a control system for a work machine adapted for use in combination with a tiltrotator with a fork carriage disposed on the work machine, and also to a tiltrotator apparatus including such a control system and a tiltrotator. [Background technology]

[0002] In construction work, it is becoming increasingly common to use tiltrotators at the outer end of the work arm of a work vehicle, such as an excavator. The tiltrotator has a lower holder 8 for holding tools, such as a compactor, hydraulic hammer, grapple, or bucket. The tiltrotator has a hydraulic tool coupler for easy tool exchange, simplifying the use of different tools, and provides both tilting and unlimited rotational movement. With a tiltrotator attached to its work arm, an excavator becomes a more useful tool carrier in that its functionality increases when tools are attached to the tiltrotator.

[0003] It has also been found that the use of a tiltrotator in combination with a fork carriage can be very effective: the availability of a fork carriage on the working arm of a work machine with a tiltrotator is very advantageous in that the fork carriage may be oriented in any rotational direction relative to the work vehicle, not just in a forward direction, and the tiltrotator offers the possibility to adapt the inclination of the fork carriage.

[0004] However, there are concerns that safety can be an issue in the commercial sector, with some manufacturers and distributors choosing not to offer fork carriages on excavators in combination with tiltrotators, as there are concerns that the combination may not be safe enough and there may be a risk of an accident due to the load tipping when held by the forks of a fork carriage positioned on the tiltrotator.

[0005] The accompanying German patent publication EP 1 099 563 A1 shows how a fork carriage can be attached to a tiltrotator for use therewith, but this publication does not address the risks involved in operating a fork carriage with a tiltrotator, such as the risk of dropping a load held by the fork carriage.

[0006] It would be advantageous to have a system that overcomes or at least mitigates at least one or some of the shortcomings of the prior art. In particular, it would be desirable to increase safety when fork carriages are used in combination with tiltrotators on work machines. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] German Patent Application Publication No. 102019106445 Summary of the Invention [Means for solving the problem]

[0008] It is an object of the present invention to provide a system that has increased safety over conventional systems when a fork carriage is used in combination with a tiltrotator on a work machine.

[0009] According to a first aspect, the present invention relates to a control system for a work machine for use with a fork carriage having forks in combination with a tiltrotator, the tiltrotator including an upper part arranged to be mounted on a work arm of the work machine and a lower part pivotally connected to the upper part, the control system being configured to be activated when the fork carriage is mounted on the lower part of the tiltrotator, the control system comprising: - an inclinometer configured to be disposed on the lower portion of the tiltrotator to sense an orientation of the lower portion with respect to gravity; - a control unit arranged to collect information from the inclinometer and relate said information to an orientation of the forks of the fork carriage, the control unit being connectable to a display unit arranged to be placed in a cabin of an operator of the work machine, the display unit being arranged to indicate the current orientation of the forks of the fork carriage based on the information from the inclinometer to assist the operator in keeping the forks of the fork carriage level with respect to gravity.

[0010] In an embodiment of the present invention, the control system also includes a display unit for placement within the operator's cabin of the work machine.

[0011] In an embodiment of the invention, the control system is configured to be manually activated by an operator when the fork carriage is mounted on the lower portion of the tiltrotator.

[0012] In an embodiment of the invention, the control system is configured to be activated by a tool recognition unit configured to automatically recognize when a fork carriage is mounted on the lower part of the tiltrotator.

[0013] In an embodiment of the invention, the control system further includes an audio unit configured to emit an audio signal to alert an operator when the inclination of the fork carriage sensed by the inclinometer exceeds a first threshold inclination relative to a horizontal orientation of the lower portion of the tiltrotator.

[0014] In an embodiment of the invention, the control system further includes a vibration unit configured to provide vibration warning feedback to an operator via the operating device to alert the operator when the operating device is controlled in a manner that exacerbates undesired tilting of the fork carriage.

[0015] In an embodiment of the invention, the control system is configured to control the display unit to show the current orientation of the lower portion of the tiltrotator with reference to a desired orientation to assist the operator in orienting the fork carriage horizontally.

[0016] Specifically, the control system may be configured to control the display unit to indicate the position of the fork carriage by a plurality of icons, including a first icon indicating a sideways tilt of the fork carriage and a second icon indicating a forward-aft tilt of the fork carriage.

[0017] In an embodiment of the invention, the control system further comprises a rotation sensor for registering the rotational position of the lower part of the tiltrotator, i.e. the rotational position of the fork carriage when disposed on the tiltrotator, the control unit is configured to collect information from the rotation sensor and relate said information to an orientation of the forks of the fork carriage, and the display unit is configured to indicate the current orientation of the forks of the fork carriage based on the information from the rotation sensor.

[0018] A rotation sensor may be positioned to register the rotational position of the lower portion of the tiltrotator relative to an initial position in which the fork carriage is pointed directly towards or directly away from the operator.

[0019] According to a second aspect, the present invention relates to a tiltrotator device including a tiltrotator having an upper part arranged to be mounted on a work arm of a work machine and a lower part pivotally connected to the upper part, the tiltrotator device comprising: - a control system as defined above, the control system being adapted to be used when a pallet loader is mounted on the lower part of the tiltrotator; - a display unit configured to indicate the current orientation of the forks of the fork carriage based on information from the inclinometer to assist the operator in keeping the forks of the fork carriage level with respect to gravity.

[0020] Other embodiments and advantages will become apparent from the detailed description and accompanying drawings.

[0021] It will be understood that all of the various examples of control systems for work machines disclosed herein also apply to tiltrotator apparatus including such control systems.

[0022] Specific embodiments of the present invention will now be described with reference to the accompanying drawings. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 shows a work vehicle having a fork carriage disposed on a tiltrotator on its work arm. [Figure 2] FIG. 10 is a diagram showing a fork carriage disposed on a tiltrotator. [Figure 3]1 is a schematic diagram showing a first embodiment of a display unit of a control system according to the invention; [Figure 4] 1 is a schematic diagram showing a first embodiment of a display unit of a control system according to the invention; [Figure 5] 1 is a schematic diagram showing a first embodiment of a display unit of a control system according to the invention; [Figure 6] 1 is a schematic diagram showing a first embodiment of a display unit of a control system according to the invention; [Figure 7] 10A-10C are schematic diagrams showing a second embodiment of the display unit of the control system for different positions of the forks of the fork carriage. [Figure 8] 10A-10C are schematic diagrams showing a second embodiment of the display unit of the control system for different positions of the forks of the fork carriage. [Figure 9] 10A-10C are schematic diagrams showing a second embodiment of the display unit of the control system for different positions of the forks of the fork carriage. [Figure 10] 10A-10C are schematic diagrams showing a second embodiment of the display unit of the control system for different positions of the forks of the fork carriage. [Figure 11] 10A-10C are schematic diagrams showing a second embodiment of the display unit of the control system for different positions of the forks of the fork carriage. [Figure 12] 10A-10C are schematic diagrams showing a second embodiment of the display unit of the control system for different positions of the forks of the fork carriage. [Figure 13] 10A-10C are schematic diagrams showing a second embodiment of the display unit of the control system for different positions of the forks of the fork carriage. [Figure 14] 10A-10C are schematic diagrams showing a second embodiment of the display unit of the control system for different positions of the forks of the fork carriage. [Figure 15]10A-10C are schematic diagrams showing a second embodiment of the display unit of the control system for different positions of the forks of the fork carriage. DETAILED DESCRIPTION OF THE INVENTION

[0024] 1 shows a work machine 6, with a fork carriage 2 attached to a tiltrotator 1 arranged at the outer end of a work arm 3 of the work machine 6. The work machine 6 includes the work arm 3 arranged to hold a tool, and a cabin 7 into which an operator of the work machine will enter when the work machine 6 is operating.

[0025] According to the present invention, a work machine is provided with a control system configured for use with a fork carriage 2 arranged on the work machine in combination with a tiltrotator 1. The tiltrotator 1 may be of a conventional type including an upper part 4 arranged to be mounted on a work arm 3 of the work machine 6, and a lower part 5 pivotally connected to the upper part 4 of the tiltrotator 1.

[0026] The fork carriage 2 includes forks 16 that extend horizontally and are arranged to hold a load placed on a pallet. Additionally, vertical support portions 15 are arranged at the inner ends of the forks 16 to provide support for the pallet and its load when held by the fork carriage 2. A body structure 14 connects the support portions 15 and the forks 16 to a tool coupler 13 that is arranged to be attached to a holder 8 in the lower part 5 of the tiltrotator 1.

[0027] In fact, the lower part 5 of the tiltrotator 1 may be said to comprise two different parts, given that the lower part 5 is tiltable relative to the upper part 4 and that the lower holder 8 is arranged to rotate relative to a main part of the lower part 5, said main part comprising the rotation motor.

[0028] The control system includes a control unit 10 configured to be located on the work machine 6 .

[0029] The control unit 10 is configured to be activated when the fork carriage 2 is mounted on the lower part 5 of the tiltrotator 1. The control system includes an inclinometer 11 located on the lower part 5 of the tiltrotator 1 to sense the orientation of the lower part 5 of the tiltrotator 1 relative to gravity. The inclinometer 11 is calibrated to sense the orientation of the forks 16 of the fork carriage 2. Thus, there is no need to place an inclinometer or any other control device on the fork carriage 2. Instead, the calibrated inclinometer 11 located on the lower part 5 of the tiltrotator 1 will provide a correct representation of the orientation of the forks 16 of the fork carriage 2.

[0030] In the embodiment shown, the inclinometer 11 is arranged in the main part of the lower part 5 and not in a lower holder 8 that is rotatable relative to the main part.

[0031] In addition to the inclinometer 11, a rotation sensor 18 may be arranged to register the rotational position of the lower part 5 of the tiltrotator 1, i.e. the rotational position of the fork carriage 2 when placed on the tiltrotator 1. The rotation sensor 18 may be arranged to register the rotational position of the lower part 5 of the tiltrotator 1 relative to an initial position in which the fork carriage 2 is oriented either directly towards or directly away from the operator.

[0032] While the rotation sensor itself is conventional to those skilled in the art, conventionally it is only available to the operator as a rotational position, i.e., as degrees relative to an initial position, and not as a graphical representation as in embodiments of the present invention.

[0033] The control system further includes a display unit 12 located within or adapted to be located within the operator's cabin 7 of the work machine 6 .

[0034] The display unit 12 is configured to indicate the current orientation of the forks 16 of the fork carriage 2 in the lower part 5 of the tiltrotator 1 based on input from the inclinometer 11 to assist the operator in keeping the forks 16 of the fork carriage 2 level with respect to gravity.

[0035] The control unit 10, inclinometer 11, rotation sensor 18 and display unit 12 are shown schematically in suggested positions in Figure 1. In Figure 2 a more specific suggested position of the inclinometer 11 in the lower part 5 of the tiltrotator 1 is shown.

[0036] The display unit 12 may typically be configured to show the current orientation of the lower part 5 of the tiltrotator 1 with the positioned fork carriage 2 with reference to a desired orientation to assist the operator in keeping the fork carriage 2 in a horizontal orientation or in bringing it to a horizontal orientation if the fork carriage 2 is tilted. Of course, considering that the coupling of the lower part 5 of the tiltrotator 1 with the positioned fork carriage 2 ensures the position of the fork carriage 2, when the orientation and tilt of the lower part 5 of the tiltrotator 1 are known, the orientation and tilt of the fork carriage 2 are also known.

[0037] In the following, the present invention will be described with reference to first and second specific embodiments of the display unit 12. However, the present invention is not limited to any particular design of the display, but only to its functionality as presented in the claims. This description is intended only to illustrate possible implementations of the present invention.

[0038] 3 to 6 are schematic diagrams of a first embodiment of a display unit 12 of a control system according to the invention.

[0039] The display unit 12 should be positioned so that it is visible to the operator of the tiltrotator 1 during operation of the tiltrotator 1. In particular, the display unit 12 may be configured to be located within the operator's cabin. The display unit 12 may conveniently be part of or integrated into a display unit located within the work machine 6. Thus, the control system does not need to include a specific display unit. Instead, the control system may be configured to fit into the display unit of the work machine 6.

[0040] For example, the control system software may be configured to be downloaded to a display unit located inside the vehicle, so that the control system does not need to include a display when provided to the customer, but instead it is sufficient that the software is available to be run on or downloaded to the display unit, or to be run on a mobile display unit, such as a mobile phone.

[0041] In the first embodiment shown, the orientation of the fork carriage 2 is indicated in four different ways based on information from both the inclinometer 11 and the rotation sensor 18. A first icon I1 in the upper left corner of the display indicates the sideways tilt of the fork carriage based on information from the inclinometer 11, and a second icon I2 in the upper right corner indicates the forward tilt of the fork carriage, also based on information from the inclinometer 11. In the center of the display, the current orientation of the fork carriage is indicated with reference to the desired orientation to assist the operator in orienting the fork carriage horizontally. In the embodiment shown, the orientation is indicated as the relative position of a display point P with respect to a correspondingly sized centrally located circle C1, with the display point P positioned exactly inside this central circle C1. An outer circle C2 is concentrically positioned outside the central circle C1 to mark the outer boundary for the allowable orientation of the fork carriage indicated by the display point P. This illustration of the display point P is based on information from both the inclinometer 11 and the rotation sensor 18.

[0042] In the embodiment shown, the third icon I3 and the fourth icon I4 are arranged to indicate the rotational position of the fork carriage in a plane perpendicular to gravity based on information from the rotation sensor 18. The third icon I3 is shown in the shape of a fork carriage and the fourth icon I4 is shown in the shape of a ring segment associated with the outer circle C2.

[0043] In Fig. 3, the display unit 12 shows the fork carriage in a horizontal orientation, where the fork carriage arranged in the tiltrotator's lower holder 8 is in a horizontal position with respect to gravity, meaning that the plane formed by the forks 16 of the fork carriage is perpendicular to the direction of gravity. Thus, in Fig. 3, the display unit 12 shows a display point P inside the central circle C1, which indicates that the fork carriage 2 is horizontal. Furthermore, the first icon I1 and the second icon I2 are both in their initial positions, which indicates that the fork carriage is horizontal with respect to sideways tilt and rearward-forward tilt, respectively. The third icon I3 and the fourth icon I4 point to the left rear, which indicates the current rotational position of the fork carriage.

[0044] In Figure 4, the display unit 12 shows the fork carriage with display point P not inside the central circle C1, indicating that the fork carriage is not level. Specifically, the fork carriage is oriented with its outer fork ends pointing downward, as indicated by both the tilted position of the second icon I2 and the fact that display point P is outside the central circle C1. However, because display point P is well inside the outer circle C2, there is no imminent risk of the load being lost from the fork carriage.

[0045] 5, the display unit 12 shows the fork carriage with display point P outside the center circle C1, indicating that the fork carriage is not level, and both the first icon I1 and the second icon I2 are offset. Thus, the fork carriage in this position is tilted sideways, and the outer fork ends of the fork carriage are also tilted so that they point downward. However, because display point P is still inside the outer circle C2, there is no imminent risk of the load being lost from the fork carriage.

[0046] In FIG. 6 , the display unit shows the fork carriage with display point P outside the central circle C1 and heading outside the outer circle C2. In certain embodiments, a warning may be issued when a certain threshold, which may correspond to crossing the outer circle C2, is exceeded. Specifically, an audio signal may be issued. In addition, a visual warning may be issued, for example, as shown in the drawing where display point P starts flashing. Furthermore, continued operation of the operating device may be prevented until the operator recognizes this critical situation, for example, by pressing a button to release operation of the operating device. Additionally, assisted operation of the operating device may be automatically provided, for example, by providing a button therefor, where the fork carriage is automatically operated to a horizontal position.

[0047] In figures 7 to 15 a second embodiment of a display unit 12 of a control system according to the invention is shown for different positions of the fork carriage 2.

[0048] In this embodiment, the display of the display unit 12 has an upper portion with the display point P, the circles C1 and C2, and the icon I4, and a lower portion with the icons I1, I2, and I3. In an embodiment of the invention, only some of these icons appear on the display unit, for example the display point P and the central circle C1.

[0049] The illustration in FIG. 7 corresponds to a situation in which the fork carriage is in its initial position, i.e., horizontal, and rotated straight back toward the cabin 7 of the work machine 6. Thus, in FIG. 7, the display unit 12 shows a display point P inside the central circle C1, indicating that the fork carriage is horizontal. Furthermore, the first icon I1 and the second icon I2 are both in their initial positions, indicating that the fork carriage is horizontal with respect to sideways tilt and rearward-forward tilt, respectively. The third icon I3 and the fourth icon I4 both indicate the rotational position of the fork carriage 2 in a plane perpendicular to gravity, and they both point downward, indicating that the forks 16 are in their initial positions. The fourth icon I4 is represented as a circular segment related to the outer circle C2.

[0050] The control system may also be connected to an audio unit, such as a speaker system on the work machine. In Figures 7-15, the audio unit is indicated by an audio icon A, which may be provided to visually indicate an audio signal. However, in the drawings of the display unit 12, the audio icon A is shown primarily to indicate when an audio signal is being emitted or not. In an embodiment of the present invention, the audio icon A is not presented on the display unit.

[0051] In the situation shown in FIG. 7, no audible signal is issued, which is indicated by an X next to the audio icon A.

[0052] 8, the fork carriage 2 has been rotated approximately 45° counterclockwise relative to its initial position, as indicated by icons I3 and I4 pointing downward and to the right, which corresponds to SE (Southeast) on the compass. The display point P is still centered inside the central circle C1, indicating that the forks 16 of the fork carriage 2 are horizontal.

[0053] In FIG. 9, the fork carriage is tilted slightly to the side, specifically to the right, as indicated by a portion of the display point P being outside the central circle C1 and by the first icon I1 being tilted (to the right).

[0054] In Figures 10 and 11, the fork carriage is tilted slightly forward and backward, respectively, as indicated by a portion of the display point P being outside the upper and lower parts of the central circle C1, respectively, and by the second icon I2 being tilted forward and backward, respectively.

[0055] For all of the situations shown in Figures 7-11, the deviation of the fork carriage from the horizontal position is small, so most of the indication points P are inside the central circle C1 and no audio warning signal is issued.

[0056] 12-15, the tilt of the fork carriage increases, causing a significant portion of the display point P to move outside of the central circle C1, as shown in FIG. 12, resulting in a first audible signal A1 being issued to alert the operator that the tilt has exceeded a first threshold, corresponding to a tilt of, for example, approximately 2-3°. In FIG. 13, the tilt of the fork carriage has caused the entire display point P to move outside of the central circle C1, thus exceeding a second threshold, corresponding to a slightly greater tilt, for example, 4-5°, resulting in a second audible signal A2 being issued, which may have a higher amplitude and / or frequency than the first audible signal A1 to ensure the operator receives a warning.

[0057] In FIG. 14, the tilt of the fork carriage causes the display point P to approach the outer circle C2, where a third audio signal A3 may be emitted, and the third audio signal A3 may have an even higher amplitude and / or a higher frequency than the second audio signal A2.

[0058] The tilt of the fork carriage in Figure 15 is such that if the fork carriage were to tilt further in the wrong direction, an accident would result. At this point, the display point P has broken through the outer circle C2, where a further visual warning may be issued, such as a flashing signal or a color change in the display. For example, the outer circle C2 may change color from a neutral color to a red or yellow warning color. In addition, at this point, a prominent (irritating) fourth audio signal A4 may be issued to encourage the operator to correct the situation.

[0059] Of course, the warning sounds are represented as four different audio signals A1-A4, but may preferably increase in amplitude and / or frequency as a function of the tilt of the fork without any obvious steps.

[0060] The control system may be provided with a "return to initial position" button which the operator can press to automatically correct the tilt of the fork carriage 2 to a horizontal position. This may be very useful if the operator loses control of the fork carriage.

[0061] The control system may be configured to be activated manually by an operator when a fork carriage is mounted on the lower part 5 of the tiltrotator 1. However, the control system may also be configured to be activated by a tool recognition unit configured to automatically recognize when a fork carriage is mounted on the lower part 5 of the tiltrotator 1. For example, the fork carriage 2 may be provided with a recognizable identification, such as for example an RFID, where a sensor 17 for recognizing the recognizable identification of the fork carriage 2 is arranged at the outer end of the tiltrotator or working arm. In the embodiment shown in Figure 2, the sensor 17 is shown schematically in the lower part 5 of the tiltrotator 1.

[0062] The tiltrotator 1 may also include an electrical swivel (not shown) for providing electrical terminal telecommunication lines to the inclinometer 11 and, when installed, the sensor 17.

[0063] As indicated above, the control system may include an audio unit (A) configured to emit an audio signal to alert an operator when the inclination of the fork carriage 2 sensed by the inclinometer 11 exceeds a first threshold inclination relative to the horizontal orientation of the lower portion 5.

[0064] Additionally, the control system may include a vibration unit (not shown) configured to provide vibration warning feedback to an operator via the operating device (not shown) to alert the operator when the operating device (not shown) is controlled in such a way as to exacerbate the undesired tilting of the fork carriage 2. The operating device may typically be a joystick.

[0065] The present invention has been described above with reference to specific embodiments. However, the present invention is not limited to these embodiments. It will be apparent to those skilled in the art that other embodiments are possible within the scope of the following claims.

Claims

1. A control system for a work machine (6) for use with a fork carriage (2) having forks (16) in combination with a tiltrotator (1), the tiltrotator (1) including an upper part (4) arranged to be mounted on a work arm (3) of the work machine (6) and a lower part (5) pivotally connected to the upper part (4), the control system being configured to be activated when the fork carriage (2) is mounted on the lower part (5) of the tiltrotator (1), the control system comprising: an inclinometer (11) configured to be placed on the lower part (5) of the tiltrotator (1) to sense the orientation of the lower part (5) relative to gravity; a control unit (10) arranged to collect information from the inclinometers (11) and relate said information to an orientation of the forks (16) of the fork carriage (2), wherein the control unit is connectable to a display unit (12) arranged to be placed in an operator's cabin (7) of the work machine (6), and wherein the display unit (12) is configured to indicate the current orientation of the forks (16) of the fork carriage (2) based on the information from the inclinometers (11) to assist the operator in keeping the forks (16) of the fork carriage (2) level with respect to gravity.

2. 2. The control system of claim 1, wherein the control system is configured to be manually activated by the operator when the fork carriage (2) is mounted on the lower part (5) of the tiltrotator (1).

3. 3. A control system according to claim 1 or 2, wherein the control system is configured to be activated by a tool recognition unit (17) configured to automatically recognize when the fork carriage (2) is mounted on the lower part (5) of the tiltrotator (1).

4. 4. The control system according to claim 1, further comprising an audio unit (A) configured to emit an audio signal (A1, A2, A3, A4) to alert the operator when the inclination of the fork carriage (2) sensed by the inclinometer (11) exceeds a first threshold inclination with respect to a horizontal orientation of the lower part (5) of the tiltrotator (2).

5. 5. The control system of claim 1, further comprising: an operating device configured to be manually operated by the operator to control the tiltrotator (1); and a vibration unit configured to provide vibration warning feedback to the operator via the operating device to alert the operator when the operating device is controlled in such a manner that an undesired tilt of the forks (16) of the fork carriage (2) worsens.

6. 6. The control system according to claim 1, wherein the control system is configured to control the display unit (12) to show a current orientation (P) of the forks (16) of the fork carriage (2) with reference to a desired orientation (C1) in a horizontal plane to assist the operator in orienting the forks (16) of the fork carriage (2) horizontally.

7. 7. The control system of claim 6, wherein the control system is configured to control the display unit (12) to indicate the position of the fork carriage (2) by a plurality of icons (I1-I4) including a first icon (I1) indicating a sideways tilt of the forks (16) of the fork carriage (2) and a second icon (I2) indicating a forward-backward tilt of the forks (16) of the fork carriage (2).

8. 8. The control system of claim 1, further comprising a rotation sensor for registering a rotational position of the lower part of the tiltrotator, i.e., a rotational position of the fork carriage when disposed on the tiltrotator, wherein the control unit is configured to collect information from the rotation sensor and relate the information to an orientation of the forks of the fork carriage, and the display unit is configured to indicate a current orientation of the forks of the fork carriage based on the information from the rotation sensor.

9. The rotation sensor (18) may be arranged to register the rotational position of the lower part (5) of the tiltrotator (1) relative to an initial position in which the fork carriage (2) is oriented directly towards or directly away from the operator.

10. A tiltrotator device including a tiltrotator (1) having an upper part (4) arranged to be attached to a working arm (3) of a working machine (6), and a lower part (5) rotatably and pivotably connected to the upper part (4), the tiltrotator device comprising: a control system according to any one of claims 1 to 9; a display unit (12) configured to indicate the current orientation of the forks (16) of the fork carriage (2) based on information from the inclinometer (11) in order to assist the operator in keeping the forks (16) of the fork carriage (2) horizontal with respect to gravity.

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