SE1750458A1

SE1750458A1 -

Info

Publication number: SE1750458A1
Application number: SE1750458-0A
Authority: SE
Original assignee: Rototilt Group Ab
Filing date: 2017-04-19

Abstract

ABSTRACT A control system (128) for an excavator (100; 200), the excavatorcomprising a movable arm (104; 204), a movable excavator thumb (232) and atiltrotator (110) attached to the arm, the tiltrotator being arranged to hold anauxiliary tool (112) which is rotatable and/or tiltable by means of the tiltrotator,wherein the control system is arranged to receive manoeuvring input from amanoeuvring device (122) manoeuvred by an operator. The control system isarranged to control the tiltrotator to rotate and/or tilt the auxiliary tool between aplurality of first positions and at least one second position. The excavator thumb ismovable between at least one rest position and a plurality of work positions. Theauxiliary tool is arranged to cooperate with the excavator thumb when the auxiliarytool is positioned in any of the at least one second position and when theexcavator thumb is positioned in any of the plurality of work positions. The controlsystem comprises a first blocker (150) arranged to block the movement of theexcavator thumb when the auxiliary tool is positioned in any of the plurality of firstpositions, and/or the control system comprises a second blocker (152) arranged toblock the rotation and/or tilting of the auxiliary tool when the excavator thumb ispositioned in any of the plurality of work positions. (Pig. 1)

Description

A CONTROL SYSTEM FOR AN EXCAVATOR AND A METHOD FORCONTROLLING AN EXCAVATOR Technical FieldAspects of the present invention relate to control systems for an excavator, which comprises a movable arm, a movable excavator thumb and atiltrotator attached to the arm, the tiltrotator being arranged to hold an auxiliary toolwhich is rotatable and/or tiltable by means of the tiltrotator. Further aspects of thepresent invention relate to methods for controlling an excavator disclosed above.Aspects of the present invention also relate to a tiltrotator and an excavator each comprising a control system.

Background of the ln ventionExcavators may be stationary or movable by being wheeled or provided with continuous tracks. Excavators often use hydraulics, such as hydrauliccylinders, to move and operate an auxiliary tool held by an arm of the excavator. Acombined rotating and tilting unit, arranged to hold the auxiliary tool, is known as atiltrotator. Some excavators are equipped with such a tiltrotator which is attachedto the arm of the excavator. By way of the tiltrotator the auxiliary tool can both betilted and rotated, providing an advantageous flexibility when operating the excavator.

Summary of Aspects of the ln ventionSome excavators provided with a tiltrotator are also equipped with an excavator thumb, which may be pivotally attached to the arm of the excavator. Ajoint of the excavator thumb may also be combined with a joint of the auxiliary tool.The excavator thumb is arranged to cooperate with the auxiliary tool, e.g. thebucket, to grip/clamp and lift an object. The inventor of the present invention hasidentified that it may be problematic to combine the tiltrotator and the excavatorthumb. When the tiltrotator has rotated and/or tilted the bucket away from theexcavator thumb, the bucket and excavator thumb cannot properly grip an object.Further, the inventor of the present invention has realised that the equipment maybe damaged or that objects accidently can be dropped, creating a safety risk, if theexcavator thumb is operated when the auxiliary tool is not in a suitable position.

The object of the present invention is to improve the operation of both anexcavator thumb and an auxiliary tool attached to a tiltrotator. 2 The above-mentioned object of the present invention is attained byproviding a control system for an excavator, the excavator comprising a movablearm, a movable excavator thumb and a ti|trotator attached to the arm. Theti|trotator is arranged to hold an auxiliary tool which is rotatable and/or tiltable bymeans of the ti|trotator. The control system is arranged to receive manoeuvringinput from a manoeuvring device manoeuvred by an operator. The control systemis arranged to control the ti|trotator to rotate and/or tilt the auxiliary tool between aplurality of first positions and at least one second position. The excavator thumb ismovable between at least one rest position and a plurality of work positions. Theauxiliary tool is arranged to cooperate with the excavator thumb when the auxiliarytool is positioned in any of the at least one second position and when theexcavator thumb is positioned in any of the plurality of work positions. The controlsystem comprises a first blocker arranged to block the movement of the excavatorthumb when the auxiliary tool is positioned in any of the plurality of first positions.

The above-mentioned object of the present invention is also attained byproviding a control system for an excavator, the excavator comprising a movablearm, a movable excavator thumb and a ti|trotator attached to the arm, the ti|trotatorbeing arranged to hold an auxiliary tool which is rotatable and/or tiltable by meansof the ti|trotator. The control system is arranged to receive manoeuvring input froma manoeuvring device manoeuvred by an operator, wherein the control system isarranged to control the ti|trotator to rotate and/or tilt the auxiliary tool between aplurality of first positions and at least one second position. The excavator thumb ismovable between at least one rest position and a plurality of work positions. Theauxiliary tool is arranged to cooperate with the excavator thumb when the auxiliarytool is positioned in any of the at least one second position and when theexcavator thumb is positioned in any of the plurality of work positions. The controlsystem comprises a second blocker arranged to block the rotation and/or tilting ofthe auxiliary tool when the excavator thumb is positioned in any of the plurality ofwork positions.

The excavator may be a hydraulic excavator. ln a hydraulic excavator, themovements of the arm, the ti|trotator, the excavator thumb and the auxiliary toolmay be effected by means of hydraulics, e.g. hydraulic cylinders. However,equipment of the excavator may also be mechanically operated, e.g. the excavator thumb. The auxiliary tool may be a bucket, or any other suitable tool. 3 The control system may be arranged to control the excavator thumb tomove between the at least one rest position and the plurality of work positions.

By means of the control systems as disclosed above, the control of thetiltrotator in combination with the excavator thumb is improved. Further, the risk ofdamaging the equipment, e.g. the tiltrotator, is reduced. Further, it is assured thatthe bucket and the excavator thumb can properly grip an object in a securemanner, i.e. that accidently dropping an object is prevented.

Further, the above-mentioned object of the present invention is attained byproviding a method for controlling an excavator, the excavator comprising amovable arm, a movable excavator thumb and a tiltrotator attached to the arm, thetiltrotator being arranged to hold an auxiliary tool which is rotatable and/or tiltableby means of the tiltrotator, the method comprising the steps of: o receiving manoeuvring input from a manoeuvring device manoeuvred by anoperator; o detecting the position of the auxiliary tool between a plurality of firstpositions and at least one second position; and o blocking the movement of the excavator thumb when the auxiliary tool ispositioned in any of the plurality of first positions.

The above-mentioned object of the present invention is also attained byproviding a method for controlling an excavator, the excavator comprising amovable arm, a movable excavator thumb and a tiltrotator attached to the arm, thetiltrotator being arranged to hold an auxiliary tool which is rotatable and/or tiltableby means of the tiltrotator, the method comprising the steps of: o receiving manoeuvring input from a manoeuvring device manoeuvred by anoperator; o detecting the position of the excavator thumb between at least one restposition and a plurality of work positions; and o blocking the rotation and/or tilting of the auxiliary tool when the excavatorthumb is positioned in any of the plurality of work positions.

Further, above-mentioned object of the present invention is also attainedby providing a tiltrotator arranged to be attached to an arm of an excavator andarranged to hold an auxiliary tool, wherein the tiltrotator comprises a controlsystem as claimed in any of the claims 1 to 8 or as disclosed below. 4 The above-mentioned object of the present invention is also attained byproviding an excavator comprising an arm, an excavator thumb and a tiltrotatorattached to the arm, the tiltrotator being arranged to hold an auxiliary tool, whereinthe excavator comprises a control system as claimed in any of the claims 1 to 8 oras disclosed below.

Positive technical effects of the embodiments of the methods, tiltrotatorand excavator may correspond to the technical effects mentioned in connectionwith the embodiments of the control system. ln this disclosure, the wording “between a plurality of first positions and atleast one second position” includes the plurality of first positions and the at leastone second position. ln this disclosure, the wording “between at least one restposition and a plurality of work positions” includes the at least one rest positionand the plurality of work positions.

Advantageous embodiments of the control systems, the method, thetiltrotator and the excavator according to the present invention and furtheradvantages with the present invention emerge from the dependent claims and the detailed description of embodiments.

Brief Description of the DrawingsThe present invention will now be described, for exemplary purposes, in more detail by way of embodiments and with reference to the enclosed drawings, in which: Fig. 1 is a schematic illustration of an excavator that includes aspects ofthe present invention; Fig. 2 is a schematic partial perspective view of embodiments of theexcavator and tiltrotator controlled by the control system accordingto aspects of the present invention; Fig. 3 shows the excavator and tiltrotator of Fig. 2 but with the excavatorthumb in a different position; Fig. 4 is a schematic partial perspective view of a further embodiment ofthe excavator and tiltrotator controlled by the control systemaccording to aspects of the present invention; Fig. 5 shows the excavator and tiltrotator of Fig. 4 but with the excavator thumb in a different position; 5 Fig. 6 shows an example of an unwanted position of the excavatorthumb and the auxiliary tool in combination; Fig. 7 schematically illustrates aspects of a method according to thepresent invention; and Fig. 8 schematically illustrates aspects of another method according to the present invention.

Detailed Description of EmbodimentsFig. 1 schematically shows a wheeled excavator 100 with a boom 102 and an arm 104 that is pivotally arranged on the boom 102. Hydraulic cylinders 106 arearranged to achieve the pivoting movement. At the free end 108 of the arm 104 atiltrotator 110 is arranged. An auxiliary tool 112 in the form of a compactor 114 isattached to the tiltrotator 110. However, it is to be understood that the auxiliary toolmay be any suitable tool, e.g. a bucket. A common supply line 116 is arranged toprovide the tools arranged at the free end 108 of the pivot arm 104 withpressurized hydraulic fluid.

The excavator 100 comprises a cabin 118 in which a display 120 isarranged. The display 120 is arranged to display the mode and position of thetiltrotator 110 and the auxiliary tool 112, respectively. The display may also bearranged to display the mode and position of an excavator thumb 232 (see Fig. 2)Further, the excavator 100 includes a manoeuvring unit 122 for manoeuvring atleast the tiltrotator 110 and the auxiliary tool 112. A hydraulic block 124 is providedon the excavator 100 to regulate the hydraulic fluid and to provide hydraulic fluid tothe functions demanding it. A control unit 126 is arranged to govern the hydraulicsystem of the tiltrotator 110. The control unit 126 may also be arranged to governthe hydraulic system of the excavation thumb 232 (see Fig. 5). The control unit126 may be located in the cabin 118 or outside the cabin 118, e.g. on the tiltrotator110 or on the arm 104. The control unit 126 is arranged to collect information fromthe manoeuvring unit 122 and to govern the hydraulic valves of the tiltrotator 110and excavator thumb 232 and the hydraulic block 124 based on this information.

With reference to Fig. 1, a control system 128 of the excavator 100, 200 isprovided. The control system 128 may be arranged to communicate with thecontrol unit 126. With reference to Fig. 2, the excavator 200 comprises a movablearm 204 and a tiltrotator 110 which is attached to the arm 204. The tiltrotator 110is arranged to hold an auxiliary tool 112. ln the embodiments of Figs. 2-5, the 6 auxiliary tool 112 is a bucket 230. However, other tools may be used. The bucket230 is rotatable and/or tiltable in relation to the arm 204 by means of the tiltrotator110. Further, the excavator 200 comprises a movable excavator thumb 232 whichis movable in relation to the arm 204 and may be pivotally attached to the arm204. Alternatively, the excavator thumb may be pivotally attached to the auxiliarytool, or one joint of the excavator thumb may be combined with a joint of theauxiliary tool, e.g. the bucket. The control system 128 is arranged to receivemanoeuvring input from the manoeuvring device 122 manoeuvred by an operator.The control system 128 is arranged to control the tiltrotator 110 to rotate and/or tiltthe auxiliary tool 112 between a plurality of first positions and at least one secondposition. The excavator thumb 232 is movable between at least one rest positionand a plurality of work positions. The control system 128 may be arranged tocontrol the excavator thumb 232 and control the excavator thumb 232 to movebetween the at least one rest position and the plurality of work positions. ln Fig. 2, the auxiliary tool 112 is in the at least one second position andthe excavator thumb 232 is in the at least one rest position. However, it is to beunderstood that the auxiliary tool 112 may be movable to a plurality of secondpositions and that the excavator thumb 232 may be movable to a plurality of restpositions. With reference to Fig. 5, the auxiliary tool 112 is arranged to cooperatewith the excavator thumb 232 when the auxiliary tool 112 is positioned in any ofthe at least one second position and when the excavator thumb 232 is positionedin any of the plurality of work positions. The control system 128 may comprise afirst blocker 150 arranged to block the movement of the excavator thumb 232when the auxiliary tool 112 is positioned in any of the plurality of first positions. lnFig. 2, the excavator thumb is in a rest position. Fig. 6 schematically illustrateswhen the auxiliary tool 612 is in any of the plurality of first positions while theexcavator thumb 632 is in a work position, i.e. when the auxiliary tool 612, held bythe tiltrotator 610, and the excavator thumb 632 together are in an unwantedposition. With reference to Fig. 1, the control system 128 may comprise a secondblocker 152 arranged to block the rotation and/or tilting of the auxiliary tool 112when the excavator thumb 232 is positioned in any of the plurality of workpositions. By combining the first and second blockers 150, 152 advantageousembodiments are provided which improve the control of the tiltrotator 110 in combination with the excavator thumb 232 and reduce the risk of damaging the 7 equipment, e.g. the tiltrotator. Further, by the combination of the first and secondblockers 150, 152 it is assured that the bucket and the excavator thumb canproperly grip an object and not drop it, whereby the safety is improved. However, itis to be understood that some embodiments may only have the first blocker 150and that other embodiments may only have the second blocker 152.

The excavator thumb 232 and the auxiliary tool 112 may be arranged tocooperate by being able to grip/clamp an object and lift and move the object. Anobject between the excavator thumb 232 and auxiliary tool 112 may for examplebe clamped by moving the excavator thumb 232 towards the auxiliary tool 112until a suitable grip is attained. The auxiliary tool 112 may be a scoop 230 or anyother suitable tool.

The control system 128 including the two blockers 150, 152 may beimplemented as software. However, the two blockers may be implemented in analternative manner. The two blockers 150, 152 may e.g. arranged to block thehydraulic fluid to the tiltrotator 110 and excavator thumb 232.

Fig. 3 corresponds essentially to Fig. 2, but with the excavator thumb 232in a work position. ln Fig. 3 the auxiliary tool 112 and excavator thumb 232 areprepared to grip/clamp an object. Fig. 4 illustrates other embodiments of theexcavator and tiltrotator. Fig 4 differs from Fig. 3 in that the supply lines 440 ofhydraulic fluid are arranged in different manners. l\/lore specifically, in Fig. 4 thereis a diverter valve 442 arranged on the arm 204 at the end of a common supplyline 444 close to the tiltrotator 110. The diverter valve 442 diverts the hydraulicfluid into two separate conduits. A first conduit 446 is provided to the tiltrotator 110,and a second conduit 448 is provided to the excavator thumb 232. ln Figs. 2-3, theexcavator thumb 232 and the tiltrotator 110 are provided with separate conduits240, 242 from the hydraulic block 124. Fig. 5 shows the embodiment of Fig. 4 butwith the excavator thumb 232 in another work position.

With reference to Figs. 1 and 5, the first blocker 150 is arranged to blockmanoeuvring input from the manoeuvring device 122 requesting movement of theexcavator thumb 232 when the auxiliary tool 112 is positioned in any of theplurality of first positions. The second blocker 152 may be arranged to blockmanoeuvring input from the manoeuvring device 122 requesting rotation and/ortilting of the auxiliary tool 112 when the excavator thumb 232 is positioned in any of the plurality of work positions. The control system 128 comprises at least one 8 first sensor 560, e.g. two Sensors, arranged to detect that the auxiliary tool 112 ispositioned in any of the at least one second position. The control system 128comprises at least one second sensor 562 arranged to detect that the excavatorthumb 232 is positioned in any of the at least one rest position. An alternative tothe second sensor 562 may be based on a scheme where the operator of theexcavator indicates that the excavator thumb is in a rest position before thetiltrotator can be operated. The manoeuvring device 122 may comprise a quickcommand 160 (see Fig. 1). When the quick command is activated by the operator,the control system 128 is arranged to rotate and/or tilt the auxiliary tool 112 to theat least one second position without any further manoeuvring input from themanoeuvring device 122. The quick command 160 provides an efficient way forthe operator to put the auxiliary tool 112 in a correct position for cooperation withthe excavator thumb 232. Alternatively, the control system 128 may comprise oneor more sensors that detect the position of the auxiliary tool 112 in any position.The control system 128 may comprise one or more sensors that detect theposition of the excavation thumb 232 in any position. The control system may forexample comprise two sensors 560 applied to the tiltrotator 110, where one sensordetects the rotation of the tiltrotator 110 and another sensor detects the tilting ofthe tiltrotator 110.

According to aspects of the invention, embodiments of a method forcontrolling an excavator are provided as shown in Fig. 7, the method comprisingthe steps of: o receiving 801 manoeuvring input from a manoeuvring device manoeuvredby an operator; o detecting 802 the position of the auxiliary tool between a plurality of firstpositions and at least one second position; and o blocking 803 the movement of the excavator thumb when the auxiliary toolis positioned in any of the plurality of first positions.

The step of blocking the movement of the excavator thumb may compriseblocking the manoeuvring input from the manoeuvring device requestingmovement of the excavator thumb.

According to further aspects of the invention, embodiments of a methodfor controlling an excavator are provided as shown in Fig. 8, the method comprising the steps of 9 o receiving 901 manoeuvring input from a manoeuvring device manoeuvredby an operator; o detecting 902 the position of the excavator thumb between at least one restposition and a plurality of work positions; and o blocking 903 the rotation and/or tilting of the auxiliary tool when theexcavator thumb is positioned in any of the plurality of work positions.

The step of blocking the rotation and/or tilting of the auxiliary toolcomprises blocking the manoeuvring input from the manoeuvring devicerequesting rotation and/or tilting of the auxiliary tool.

Aspects of the present invention include a tiltrotator arranged to beattached to an arm of an excavator and arranged to hold an auxiliary tool, whereinthe tiltrotator comprises a control system as disclosed above in connection withvarious embodiments.

Aspects of the present invention include an excavator 100, 200 whichcomprises an arm 104, 204 an excavator thumb 232 and a tiltrotator 110 attachedto the arm 204, wherein the tiltrotator 110 is arranged to hold an auxiliary tool 112,and wherein the excavator 100, 200 comprises a control system 128 according toany embodiment as disclosed above. The excavator 100, 200 may be a tractor orany other suitable vehicle or apparatus. Embodiments of the excavator 100, 200may be stationary or movable by being wheeled or provided with continuoustracks. The excavators may use hydraulics, such as hydraulic cylinders to moveparts of the excavator.

An advantageous scheme that can be combined with embodiments of thepresent invention is that the auxiliary tools to be used are marked with an identity,e.g. by being provided with an RFID or Bluetooth tag/mark, and are automaticallyidentified by the control system. When identified, the control system can block theuse of the excavator thumb if a certain auxiliary tool is attached to the tiltrotator.An alternative is for the operator to manually provide the control system with thetool identity to be connected to the tiltrotator.

The features of the various embodiments disclosed above may becombined in various possible ways providing further advantageous embodiments. ln the embodiments disclosed above, a bucket is attached to the tiltrotator.However, it is to be understood that other auxiliary tools may be attached to the tiltrotator.

The invention shall not be considered limited to the embodimentsillustrated, but can be modified and altered in many ways by one skilled in the art,without departing from the scope of the appended claims.

Claims

11 CLAIIVIS

1. A control system (128) for an excavator (100; 200), the excavatorcomprising a movable arm (104; 204), a movable excavator thumb (232) and atiltrotator (110) attached to the arm, the tiltrotator being arranged to hold anauxiliary tool (112) which is rotatable and/or tiltable by means of the tiltrotator,wherein the control system is arranged to receive manoeuvring input from amanoeuvring device (122) manoeuvred by an operator, wherein the control systemis arranged to control the tiltrotator to rotate and/or tilt the auxiliary tool between aplurality of first positions and at least one second position, and the excavatorthumb is movable between at least one rest position and a plurality of workpositions, wherein the auxiliary tool is arranged to cooperate with the excavatorthumb when the auxiliary tool is positioned in any of the at least one secondposition and when the excavator thumb is positioned in any of the plurality of workpositions, wherein the control system comprises a first blocker (150) arranged toblock the movement of the excavator thumb when the auxiliary tool is positioned in any of the plurality of first positions.

2. A control system (128) for an excavator (100; 200), the excavatorcomprising a movable arm (104; 204), a movable excavator thumb (232) and atiltrotator (110) attached to the arm, the tiltrotator being arranged to hold anauxiliary tool (112) which is rotatable and/or tiltable by means of the tiltrotator,wherein the control system is arranged to receive manoeuvring input from amanoeuvring device (122) manoeuvred by an operator, wherein the control systemis arranged to control the tiltrotator to rotate and/or tilt the auxiliary tool between aplurality of first positions and at least one second position, and the excavatorthumb is movable between at least one rest position and a plurality of workpositions, wherein the auxiliary tool is arranged to cooperate with the excavatorthumb when the auxiliary tool is positioned in any of the at least one secondposition and when the excavator thumb is positioned in any of the plurality of workpositions, wherein the control system comprises a second blocker (152) arrangedto block the rotation and/or tilting of the auxiliary tool when the excavator thumb is positioned in any of the plurality of work positions. 12

3. A control system (128) according to the claim 1, characterised in that thefirst blocker (150) is arranged to block manoeuvring input from the manoeuvringdevice (122) requesting movement of the excavator thumb (232) when theauxiliary tool (112) is positioned in any of the plurality of first positions.

4. A control system (128) according to claim 1 or 3, characterised in that thecontrol system comprises a second blocker (152) arranged to block the rotationand/or tilting of the auxiliary tool (112) when the excavator thumb (232) ispositioned in any of the plurality of work positions.

5. A control system (128) according to claim 2 or 4, characterised in that the(152)manoeuvring device (122) requesting rotation and/or tilting of the auxiliary tool second blocker is arranged to block manoeuvring input from the(112) when the excavator thumb (232) is positioned in any of the plurality of workpositions.

6. A control system (128) according to any of the claims 1 to 5,characterised in that the control system comprises at least one first sensor (560)arranged to detect that the auxiliary tool (112) is positioned in any of the at leastone second position.

7. A control system (128) according to claim 6, characterised in that themanoeuvring device (122) comprises a quick command (160), and when activatedby the operator, the control system is arranged to rotate and/or tilt the auxiliary tool(112) to the at least one second position without any further manoeuvring inputfrom the manoeuvring device.

8. A control system (128) according to any of the claims 1 to 7,characterised in that the control system comprises at least one second sensor(562) arranged to detect that the excavator thumb (232) is positioned in any of theat least one rest position.

9. A method for controlling an excavator, the excavator comprising a movable arm, a movable excavator thumb and a tiltrotator attached to the arm, the 13 tiltrotator being arranged to hold an auxiliary tool which is rotatable and/or tiltableby means of the tiltrotator, the method comprising the steps of:o receiving (801) manoeuvring input from a manoeuvring device manoeuvredby an operator;o detecting (802) the position of the auxiliary tool between a plurality of firstpositions and at least one second position; ando blocking (803) the movement of the excavator thumb when the auxiliary tool is positioned in any of the plurality of first positions.

10. A method for controlling an excavator, the excavator comprising amovable arm, a movable excavator thumb and a tiltrotator attached to the arm, thetiltrotator being arranged to hold an auxiliary tool which is rotatable and/or tiltableby means of the tiltrotator, the method comprising the steps of:o receiving (901) manoeuvring input from a manoeuvring device manoeuvredby an operator;o detecting (902) the position of the excavator thumb between at least onerest position and a plurality of work positions; ando blocking (903) the rotation and/or tilting of the auxiliary tool when the excavator thumb is positioned in any of the plurality of work positions.

11. A method according to the claim 9, characterised in that the step ofblocking the movement of the excavator thumb comprises blocking themanoeuvring input from the manoeuvring device requesting movement of the excavator thumb.

12. A method according to claim 9 or 11, characterised in that the methodcomprises the step ofo blocking the rotation and/or tilting of the auxiliary tool when the excavatorthumb is positioned in any of the plurality of work positions.

13. A method according to claim 10 or 12, characterised in that the step of blocking the rotation and/or tilting of the auxiliary tool comprises blocking the 14 manoeuvring input from the manoeuvring device requesting rotation and/or tilting of the auxiliary tool.

14. A tiltrotator (110) arranged to be attached to an arm (104; 204) of anexcavator (100; 200) and arranged to hold an auxiliary tool (112), wherein the tiltrotator comprises a control system (128) as claimed in any of the claims 1 to 8.

15. An excavator (100; 200) comprising an arm (104; 204), an excavatorthumb (232) and a tiltrotator (110) attached to the arm, the tiltrotator beingarranged to hold an auxiliary tool (112), wherein the excavator comprises a control system (128) as claimed in any of the claims 1 to 8.