Operating element for steering control

Abstract

An operating element for controlling the steering of a vehicle is provided. The operating element (10) comprises a finger input part (20) that is rotatable about a rotation axis (15). The finger input part (20) is configured to be actuatable by a finger of a user and comprises a finger actuation surface (21) configured to be engaged by the finger of the user to actuate the finger input part. A tracking unit (30) for tracking an actual steering angle of the vehicle (200) is provided, wherein the tracking unit (30) comprises an actuator (40) that is controllable to actively change a position of the finger input part (20) based on the actual steering angle (γ) of the vehicle (200) and / or that is controllable to actively change a force or torque applied to the finger input part (20) based on the actual steering angle (y) of the vehicle (200). A sensor unit (60) detects at least one of an angular position (86) of the finger input part (20) and / or a force or torque applied to the finger input part (20) for controlling the steering of the vehicle (200).

Description

[0001] OPERATING ELEMENT FOR STEERING CONTROL

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to an operating element for controlling a steering of a vehicle, in particular an off-highway vehicle, to a respective steering control system and to a corresponding method. It may further relate to a vehicle comprising such operating element.

[0004] BACKGROUND

[0005] Operating elements such as joysticks are regularly used to control functions of a machine, e.g. an off-highway mobile machine, such as a construction vehicle, agricultural vehicle, or industrial vehicle. For controlling the steering of such vehicle, a steering wheel is usually provided, wherein a steering angle of the vehicle is controlled based on the angle by which the steering wheel is turned. This may occur either mechanically, hydraulically, e.g. via a respective power steering system, or electrically (e.g., steer by wire).

[0006] The use of such steering wheel often results in neck and shoulder pain when used for longer periods of time. Turning maneuvers or driving in the Y-cycle require frequent changes in steering direction, which require many turns of the steering wheel and are therefore time consuming and strain the driver. To avoid these negative effects, it is known to use joysticks for steering an off-highway vehicle, such as a tractor. Such joystick may take the strain off the shoulder muscles. Further, the movement of the joystick from a left stop to a right stop may be faster than with a steering wheel, which may shorten the time required for steering maneuvers.

[0007] However, known joystick operation still leads to strain for the user. Operating the steering joystick for example puts more strain on the wrist than operating a steering

[0008] P25010PCT - Kahler Kdck Mollekopf - 92b581 a9-6304-4592-979c-2ff71 d383b4dwheel. Further, such joysticks are relatively bulky in order to implement the functionality required for steering a vehicle. Further improvements to the steering of an off-highway vehicle are thus desirable.

[0009] SUMMARY

[0010] Accordingly, there is a need to mitigate at least some of the drawbacks mentioned above and to provide improvements to the operating element for controlling the steering of a vehicle. It is particularly desirable to reduce space requirements of such operating element and to reduce strain experienced by a user when operating such operating element.

[0011] This need is met by the features of the independent claims. The dependent claims describe embodiments of the invention.

[0012] According to an aspect of the invention, an operating element for controlling the steering of a vehicle is provided. The operating element comprises a finger input part that is rotatable about a rotation axis. The finger input part is configured to be actuatable by a finger of a user, preferably by only one finger. It comprises a finger actuation surface configured to be engaged by the finger of the user to actuate the finger input part. The operating element further comprises a tracking unit for tracking an actual steering angle of the vehicle. The tracking unit comprises an actuator that is controllable to actively change a position of the finger input part based on the actual steering angle of the vehicle and / or that is controllable to actively change a force or torque applied to the finger input part based on the actual steering angle of the vehicle. It further comprises a sensor unit configured to detect at least one of an angular position of the finger input part and / or a force or torque applied to the finger input part for controlling the steering of the vehicle.

[0013] Such operating element may provide several benefits. The operating element allows the control of the steering of the vehicle by using the finger, e.g. the thumb. This may significantly relieve the user’s body from strain, such as caused by repeated flexing of the wrist when using a joystick. It may further provide a fast and efficient adjustment of the steering of the vehicle between maximum steering angles in both directions by means of the finger or thumb. Furthermore, the tracking unit can provide feedback on the steering angle. For example, it allows a neutral position of the finger input part to be adjusted to an angle in correspondence with the steering angle, so that a restoring torque

[0014] P25010PCT - Kahler Kack Mollekopf - 92b581 a9-6304-4592-979c-2ff71 d383b4dtowards the neutral position applied to the finger input part will become increasingly smaller until, upon the steering angle reaching the position prescribed by the angular position of the finger input part, the neutral position reaches the angular position of the finger input part. This may provide an intuitive control of the steering. Further, the current steering angle may be kept even if the finger is briefly released.

[0015] Even further, since the operating element is actuated by the finger, e.g. the thumb, the finger input part has a shorter lever arm to the rotation axis than for example a joystick. Also, the finger generally applies a smaller force than a whole hand of a user. Therefore, the mechanical elements can be designed smaller, and the actuator used to provide feedback on the steering angle may likewise be dimensioned smaller. Consequently, the operating element may be more compact than existing solutions. The power consumption may further be reduced in view of the reduced actuator size. Even further, in view of the reduced size, the risk of an unwanted actuation of the operating element, for example by the user bumping into the operating element, may be reduced significantly. A joystick is in contrast sticking out from the armrest or a control panel of the vehicle and can easily be actuated accidentally by a user, e.g. if the user or his clothes get caught on the joystick.

[0016] The finger input part may directly or indirectly be connected to the actuator.

[0017] Accordingly, the position change and / or the change of applied force or torque may be effected directly or indirectly (e.g. via one or more mechanical parts, e.g. via a link comprising a spring) by the actuator. The actuator may for example directly apply a force or torque to the finger input part, or the actuator may apply a force or torque to an intermediate part (such as the base part described below) which may in turn apply a force or torque to the finger input part.

[0018] In a preferred embodiment, the finger input part has a neutral position from which it is deflectable, wherein the actuator is controllable to actively change the neutral position of the finger input part based on the actual steering angle of the vehicle. In particular, the configuration may be such that the change of position of the finger input part and / or change of force or torque applied to the finger input part by the actuator is performed so as to actively change the neutral position of the finger input part based on the actual steering angle of the vehicle.

[0019] A neutral position of the finger input part may for example be a position towards which a restoring torque applied to the finger input part acts; it may for example be a position

[0020] P25010PCT - Kahler Kack Mollekopf - 92b581 a9-6304-4592-979c-2ff71 d383b4dto which the finger input part returns if released by the user. The neutral position may for example be a position at which no restoring torque acts on the finger input part.

[0021] The finger actuation surface may be a surface which the finger touches when actuating the operating element with the finger, for example on which the finger rests.

[0022] In a preferred embodiment, the finger input part is a thumb input part configured to be actuatable by only a thumb of the user. The finger actuation surface may then be engaged by the thumb to actuate the input part.

[0023] For example, the thumb input part may comprises a thumb rest configured to provide a rest for the thumb of the user. For example, the thumb rest may provide or constitute the finger actuation surface.

[0024] The thumb input part may for example be a thumb wheel, a thumb lever, and / or a thumb rocker, or the like.

[0025] The detection of the angular position of the finger input part may occur by detecting a deflection angle as an absolute deflection with respect to a default position of the finger input part (which may correspond to a zero steering angle), e.g. with respect to a stationary component of the operating element (such as a housing or actuator body), or by detecting an angular position as a relative position with respect to the neutral position. In the latter case, since the neutral position may be known, the absolute angular position, e.g. absolute deflection angle, may also be known. Preferably, the absolute angular position of the finger input part is detected and is provided as a target for the steering angle of the vehicle. It is also possible that the sensor unit measures a force or torque applied to the finger input part (e.g. by measuring strain, which is indicative of the applied force or torque), and that from the measured force or torque a target for the steering angle of the vehicle is derived.

[0026] That the finger input part is actuatable by only one finger of a user, e.g. by only a thumb, may mean that the finger alone, e.g. the thumb, can rotate the finger input part in both directions about the rotation axis (in particular while the finger stays in engagement with the same finger actuation surface). This is not possible for a joystick, which needs to be gripped by the hand of a user. It should be clear that in practice, another finger other than the thumb may be used as well to effect the rotation of the finger input part, such as the index finger, middle finger or another finger. Two fingers

[0027] P25010PCT - Kahler Kack Mollekopf - 92b581 a9-6304-4592-979c-2ff71 d383b4dmay be employed as well for actuating the operating element, but are not needed, as the operating element allows single finger operation. If a thumb rest configured to receive the thumb of the user is provided, operation by a different finger may be less favourable.

[0028] In some embodiments, the finger input part may be configured to be actuated by an index finger or a middle finger.

[0029] In an embodiment, the thumb rest has a concavely shaped rest surface configured to provide a rest for the thumb of the user. This may allow an ergonomic control. In particular, the thumb rest and the operating element may be configured such that the full steering range of the vehicle is controllable by the operating element without the user having to lift the thumb from the thumb rest. The concavely shaped rest surface may provide the finger actuation surface of the finger input part.

[0030] In an embodiment, the actuator is or comprises a motor having a rotation axis. The rotation axis of the motor may be parallel to or may coincide with the rotation axis of the thumb input part. Such alignment of the rotation axes may achieve a compact configuration. The need for a transmission mechanism may be avoided.

[0031] The actuator may be one or a combination of a brushless motor, a DC motor, a gimbal motor, preferably a single axis gimbal motor, or a stepper motor. A brushless DC motor, e.g. a brushless DC single axis gimbal motor is preferred. It may allow a precise position control of the angular position of the neutral position.

[0032] The operating element may comprise an operating element controller.

[0033] The operating element controller may be configured to control the actuator to actively change the position of the finger input part based on the actual steering angle and / or to actively change the force or torque applied to the finger input part based on the actual steering angle of the vehicle. The operating element controller may for example be configured to receive the actual steering angle of the vehicle and to change the position and / or change the applied force or torque based thereon.

[0034] The operating element controller may in particular be configured to control the actuator to actively change the neutral position of the finger input part based on the actual steering angle of the vehicle, e.g. based on the received actual steering angle.

[0035] P25010PCT - Kahler Kack Mollekopf - 92b581 a9-6304-4592-979c-2ff71 d383b4dThe operating element controller may be configured to generate, based on a detected angular position of the finger input part, a signal indicative of a target for the steering angle of the vehicle and to give out the signal, e.g. towards a steering controller of the vehicle. As the steering angle changes, the angular position of the neutral position, which tracks the actual steering angle, may be driven towards the angular position of the finger input part. At this position, the steering angle of the vehicle corresponds to the angular position of the finger input part.

[0036] In an embodiment, the tracking unit comprises a restoring unit configured to restore an angular deflection of the finger input part to the neutral position. The restoring unit may for example apply a restoring torque to the finger input part upon deflection of the finger input part from the neutral position. The restoring torque may for example depend on the amount of deflection. By means of such restoring unit, a technically simple mechanical solution may be provided that generates a restoring torque for restoring the finger input part to the neutral position.

[0037] The operating element controller may be configured to receive the actual steering angle of the vehicle and to control the actuator to change the angular position of the neutral position (e.g. as defined by the restoring unit) in accordance with the received actual steering angle.

[0038] In an optional example, the tracking unit may comprise a base part that is rotatable about a base part rotation axis. The base part may define the neutral position of the restoring unit so that the neutral position is angularly displaced (i.e. rotated) about the base part rotation axis if the base part is rotated. The actuator may be mechanically coupled to the base part to rotate the base part. A simple mechanical configuration of the tracking unit may thereby be provided.

[0039] The base part rotation axis may coincide with (may be identical with) the rotation axis of the actuator, and / or the base part rotation axis may coincide with the rotation axis of the finger input part. A compact configuration may thus be provided.

[0040] For example, the actuator may be directly mechanically connected to the base part without an intervening transmission mechanism. An even more compact configuration may thereby be achieved. This may further facilitate control of the actuator. Wear of the operating element may also be reduced, since there are fewer movable parts. Further, by

[0041] P25010PCT - Kahler Kack Mollekopf - 92b581 a9-6304-4592-979c-2ff71 d383b4davoiding the use of such transmission mechanism, the costs for material and manufacturing may be reduced and manufacturing may be accelerated.

[0042] Preferably, the actuator is a motor and the base part is directly connected to a rotational output of the motor so as to rotate with the rotational output. As an example, the base part may be mounted to an output disc or output shaft of the motor, e.g. by a screw connection, interference fit or the like. As another example, the base part may have a mounting part or shaft that may be received by a motor output coupling, e.g. a rotating seat or the like.

[0043] The finger input part may be rotationally supported by the actuator, by the base part, and / or by a housing of the operating element. The finger input part may be restored by the restoring unit to the neutral position defined by the base part but may otherwise rotate freely in the respective support. The finger input part may for example comprise a shaft section that is rotatably received in an output coupling of the actuator, e.g. in a hole therein (so that it can freely rotate against the output coupling). This may make the configuration even more compact.

[0044] In an exemplary implementation, the base part is or comprises a disc section comprising one or more seats for the restoring unit and is mounted to an output disc of the actuator, e.g. a motor. Two seats for the restoring unit are preferred.

[0045] The restoring unit may comprise at least one spring configured to generate a restoring torque for returning the finger input part to the neutral position. Preferably, the at least one spring is arranged to act between the finger input part and the base part of the tracking unit. Optionally, the at least one spring is a double torsion spring, wherein each leg of the double torsion spring rest on a respective seat of the base part. The restoring unit may thus comprise one two-legged torsion spring that provides a restoring torque in both directions of angular deflection of the finger input part from the neutral position. By using such double torsion spring, the return torque for both directions of angular deflection may substantially be the same; asymmetries may be avoided. Further, the equilibrium, i.e. the midpoint, at the neutral position may be better defined.

[0046] The finger input part may also comprise two seats for the legs of the spring. Upon rotation of the finger input part, one of these seats may take along the leg of the spring and lift it off the seat of the base part, while the other leg rests against the seat of the base part, so that the relative displacement of the two legs increases the spring tension.

[0047] P25010PCT - Kahler Kack Mollekopf - 92b581 a9-6304-4592-979c-2ff71 d383b4dIn a further embodiment, the actuator is mechanically coupled to the finger input part to directly rotate the finger input part about the rotation axis. In such embodiment, no restoring unit and no base part may be present.

[0048] The operating element may for example comprise an operating element controller configured to control the actuator of the tracking unit. The operating element controller may be configured to control the actuator to apply a restoring torque to the finger input part towards a neutral position of the finger input part upon an angular deflection of the finger input part (by a user) from the neutral position. Accordingly, the operating element controller may define the angular position of the neutral position and may change the angular position of the neutral position in accordance with the actual steering angle, and the actuator may be controlled so as to generate the respective neutral position by applying the restoring torque towards the neutral position.

[0049] Such configuration may have the advantage that the number of mechanical components is reduced significantly. The finger input part may directly be driven by the actuator, and the actuator may be controlled to both apply the restoring torque and track the actual steering angle of the vehicle by changing the neutral position of the finger input part.

[0050] The operating element controller may for example be configured to receive the actual steering angle of the vehicle and to change the angular position of the neutral position (e.g. as defined by the controller) in accordance with the received actual steering angle. In such embodiment, the neutral position may for example be set by the operating element controller by defining in the employed control scheme the position at which no restoring torque is to act on the finger input part. The operating element may thus operate in correspondence to the above -de scribed embodiment, with the difference that the neutral position is not changed by rotating a mechanical component (e.g. the base part) but by defining the neutral position in the actuator control.

[0051] The actuator may be controlled based on a signal generated by at least one closed-loop controller or regulator. The at least one closed-loop controller or regulator may comprise a (closed-loop) position controller and / or a (closed-loop) force or torque controller. The operating element controller may implement a respective controller or regulator, in particular a (closed-loop) position controller and / or a (closed-loop) force or torque controller, by means of which the operating element controller may generate a

[0052] P25010PCT - Kahler Kack Mollekopf - 92b581 a9-6304-4592-979c-2ff71 d383b4dsignal to control the actuator (in particular to control the position of the finger input part by the actuator and / or to control the force or torque applied to the finger input part by the actuator).

[0053] In an embodiment, the sensor unit comprises a force sensing element configured to sense a force and / or torque applied to the finger input part. The force and resulting torque that the user applies to the finger input part may thus be measured by the operating element. For example, should the actuator unexpectedly become nonfunctional, e.g. stuck, user input may still be detected by such sensing element so that even if the finger input part is directly connected to the actuator, the vehicle remains controllable. The force sensing element may for example be implemented as a strain gauge or the like.

[0054] The operating element controller may be configured to operate a force control scheme to control the restoring torque applied by the actuator to the finger input part. The operating element may for example operate an impedance control scheme, in particular an active impedance control scheme, to control the restoring torque. For example, the operating element controller may comprise the sensing element to sense the force and / or torque applied to the finger input part and the operating element controller may receive a respective signal from the sensing element as input (e.g. feedback) for the force control scheme. It is noted that although such control scheme is termed ‘force control’ in the art, it is clear that it controls the torque applied by the actuator in the present case.

[0055] For example, in such impedance control scheme, the actuator control may emulate a spring-damper-mass system and thus a spring force acting on the finger input part (for example in correspondence to a torsion spring acting in one or both directions of rotation). Accordingly, application of the restoring torque to the finger input part towards the neutral position may be facilitated.

[0056] In any of the embodiments, the operating element controller may operate a position control scheme (e.g. in parallel to or as part of the torque control scheme). The position control scheme may be operated to control the neutral position of the finger input part based on the actual steering angle. As mentioned above, the actual steering angle may be controlled, e.g. by a steering controller of the vehicle, based on the angular position of the finger input part. Thus, a position control loop may be completed.

[0057] P25010PCT - Kahler Kdck Mollekopf - 92b581 a9-6304-4592-979c-2ff71 d383b4dThe sensor unit may be configured to detect the angular position of the finger input part, for example relative to a housing of the operating element or relative to an actuator body of the actuator. The operating element controller may control the restoring torque applied by the actuator as a function of the difference between the angular position of the finger input part and the angular position of the neutral position, as determined by the position control.

[0058] In an embodiment, the finger input part (e.g. thumb input part) comprises a fingerwheel cap (e.g. thumbwheel cap) and a support part. The support part may be rotationally supported and may comprise a mounting part extending in radial direction from the rotation axis. The fingerwheel cap may be mounted to the mounting part or integrally formed therewith. The mounting part may be in the form of a respective lever extending from a section by which the support part is rotationally supported. A compact configuration may thus be achieved that transmits a motion of the fingerwheel cap via the mounting part / lever to a rotation about the rotation axis.

[0059] The support part may have a respective shaft section by which it is supported by the base part, the actuator, and / or the housing, as mentioned above.

[0060] The at least one spring may act between the support part and the base part. The support part may have one or more spring seats for the at least one spring, as mentioned above. The support part may comprise a spring support, e.g. a protrusion on which the helical part of the spring rests.

[0061] The support part may be a single integral piece, i.e. may be formed integrally as a single piece. The fingerwheel cap may be mounted thereto, e.g. using a snap fit.

[0062] The support part may be positioned in a direction of an actuator rotation axis adjacent to an actuator output, and / or the fingerwheel cap may be arranged in a radial direction perpendicular to the actuator rotation axis outwardly adjacent to the actuator and may extend in the direction of the actuator rotation axis over the actuator and over the mounting part. The size of the operating element may thereby further be reduced, since the finger input part and the actuator can be provided in a rather small space.

[0063] The finger input part may extend in a rotation direction about the rotation axis partially around the actuator of the tracking unit. This may allow the additional space required

[0064] P25010PCT - Kahler Kack Mollekopf - 92b581 a9-6304-4592-979c-2ff71 d383b4dfor the rotation of the finger input part to be kept rather small, since the rotation may occur about the actuator.

[0065] For example, part of the actuator of the tracking unit may be arranged within a space that is partially surrounded by the finger input part.

[0066] In an embodiment, the actuator has a cylindrical shape. An inwardly facing shape of the finger input part may be adapted to outer shape of the actuator. This may provide a compact design in which the finger input part can rotate about the actuator, in particular if both rotation axes coincide.

[0067] For example, the finger input part may comprise a cylinder jacket section adapted to an outer shape of the actuator, e.g. to the cylindrical shape.

[0068] An encoder may be included in or mounted to the actuator and the finger input part may in a similar manner extend partially about the encoder.

[0069] The operating element may comprise a housing configured to receive the actuator, e.g. a cylindrical motor. The housing may only partially enclose the actuator, and a part of the actuator may be enclosed by the finger input part. The housing may for example comprise a space shaped as a cylinder section for taking up the actuator, e.g. as a half-cylindrical section.

[0070] The operating element may further comprise a tracking position detector, such as an encoder, configured to detect an angular position of the actuator, e.g. a rotation angle of the rotational output, e.g. of a motor. Such tracking position detector may allow a precise detection of the position to which either the base part or the finger input part is adjusted.

[0071] For example, if a respective restoring unit is employed, the tracking position detector may detect an angular position of the neutral position adjusted by the tracking unit. It may in particular detect the tracking position (angle) to which the tracking unit has moved the neutral position, e.g. the angular position of the base part.

[0072] If the finger input part is directly coupled to the actuator, the tracking position detector may detect the angular position of the finger input part. As such, it may form part of the sensor unit.

[0073] P25010PCT - Kahler Kdck Mollekopf - 92b581 a9-6304-4592-979c-2ff71 d383b4dThe tracking position detector may have a cylindrical shape. The tracking position detector may be arranged next to the actuator (e.g. cylindrical motor) on an opposite side of the base part. A cylinder diameter of the actuator and of the tracking position detector may be similar or the same. This may further improve the compactness.

[0074] A part of the finger input part, in particular a fingerwheel cap thereof, may slide on the actuator, a tracking position detector, and / or a housing of the operating element. This may further reduce the spaced requirements of the operating element.

[0075] In an embodiment, the sensor unit comprises a Hall sensor or an optical sensor configured to detect the angular position of the finger input part.

[0076] If the finger input part is directly coupled to the actuator, the Hall sensor or an optical sensor may be provided in addition or instead of the tracking position detector. The latter configuration may reduce the number of parts of the operating element. If a respective restoring unit is employed, the Hall sensor or an optical sensor may be provided in addition to the tracking position detector. This may allow detecting the position of both the finger input part and the base part, which move independently.

[0077] For example, the sensor unit may comprise a permanent magnet mounted to the finger input part and a Hall sensor arranged to detect a change of a magnetic field generated by the permanent magnet upon rotation of the finger input part. The Hall sensor is preferably mounted to a housing of the operating element. The detection may thus be performed reliably without the need to provide additional space for accommodating the detection. The magnet may for example simply be attached to a suitable position of the finger input part. A movement and / or a rotation of the magnetic field generated by the permanent magnet may for example be detected.

[0078] The magnet and the Hall sensor may form an exemplary implementation of an angle sensor configured to detect an (absolute) angular position of the finger input part. The angular position may for example be converted into a target steering angle by the respective control.

[0079] As the position of the actuator and thus the neutral position may be known (e.g. from the encoder or from the control of the actuator), it is also possible to generate an adjustment signal for the steering of the vehicle based on an angular position of the

[0080] P25010PCT - Kahler Kdck Mollekopf - 92b581 a9-6304-4592-979c-2ff71 d383b4dfinger input part with respect to the neutral position. Also, it is conceivable to measure the angular position of the finger input part from the base part to generate such adjustment signal, which a controller may convert into a change of the steering angle.

[0081] The finger input part may be deflectable (e.g. rotatable) from the neutral position within a deflection angle range. The tracking unit may be configured to adjust the neutral position within a tracking angle range. The tracking angle range may correspond to a steering (angle) range of the vehicle. For example, either border (maximum angle in positive or negative direction) of the tracking angle range may correspond to a maximum steering angle in the respective steering direction. The operating element, in particular the deflection angle range, may be configured such that when the tracking unit positions the neutral position at a border position of the tracking angle range, the finger input part is (still) deflectable over the full tracking angle range (which corresponds to the steering range). By such configuration, a jamming of the tracking mechanism may not result in that the steering range of the vehicle becomes restricted. Although in such case, feedback may be lost, the finger input part may still be deflectable to angular positions that correspond to the full steering angle range. The vehicle may thus remain fully controllable.

[0082] The deflection angle range may in particular be twice the tracking angle range.

[0083] The limits or borders of the deflection angle range may for example be defined by the tracking unit, in particular the base part, and angular position of these borders may change when the neutral position in changed by the tracking unit.

[0084] A default position (e.g. default tracking angle) of the tracking unit may corresponds to a zero angle steering angle (i.e. straight driving). The borders of the tracking angle range may be symmetrical with respect to such default position.

[0085] In an embodiment, the operating element further comprises a support handle configured to be mounted to the vehicle. The finger input part is mounted to the support handle. The support handle may be fixed or may be deflectable about one or more degrees of freedom, e.g. one or more axes. Preferably, the operating element comprises one or more sensing elements arranged to detect the deflection of the support handle in the one or more degrees of freedom.

[0086] P25010PCT - Kahler Kack Mollekopf - 92b581 a9-6304-4592-979c-2ff71 d383b4dThe one or more sensing elements may be configured to provide an output signal for controlling a function of the vehicle. For example, the operating element may be configured to control a direction of motion of the vehicle in dependence on the deflection of the support handle. The deflection in one direction may switch to a forward motion and the deflection in the opposite direction may switch to a rearward motion. The sensing element may for example comprise respective switches which may be arranged so that the deflection in one direction actuates one switch and deflection in the opposite direction actuates another switch. This may be detected to control the direction of vehicle motion, e.g. by the operating element controller.

[0087] In an embodiment, the operating element further comprises a support handle having a gripping area configured to receive a hand of a user (for example configured to be gripped by the hand or to provide a rest for the user’s hand). The finger input part may be mounted to the support handle in an area next to the gripping area. This may facilitate operation of the finger input part by the user.

[0088] The support handle may have a mounting base configured to be mounted to the vehicle (for example to an armrest of the vehicle or to a control panel of the vehicle). The gripping area of the support handle may not be movable with respect to the mounting base. A firm rest for the user’s hand may thus be provided that further reduces strain. No accidental control action may further be taken if the user bumps into such fixedly mounted support handle. The fixed support handle may further result in that the hand is less affected by shocks and vibrations, thus reducing the risk of unintentional deflection of the lever. Overload forces may also be better absorbed by a fixed handle than by a movable joystick handle.

[0089] The mounting base and handle can be formed integrally, i.e. they can be a single integral piece.

[0090] The support handle may be a control handle or control grip.

[0091] The support handle may be configured such that a finger of the user’s hand can reach the finger input part when the hand grips the gripping area of the handle. Full steering control and a safe grip may thus be obtained at the same time. The user can rest the hand on handle, so that the hand is firmly supported and does not need to be moved; steering may then only occur by means of the finger, in particular the thumb.

[0092] P25010PCT - Kahler Kack Mollekopf - 92b581 a9-6304-4592-979c-2ff71 d383b4dThe support handle may have the shape of a joystick control lever but may not be movable. The support handle may be ergonomically formed.

[0093] The support handle may comprise one or more control elements, for example one or more, or a combination of, a button, a switch, a conventional thumbwheel, a rocker, and / or the like. As the support handle may be fixed, actuation of such additional control elements may be facilitated. The fingers of the hand do not need to firmly grip the support lever (as required for a conventional movable joystick), so that the fingers can more easily operate the one or more control elements.

[0094] According to a further embodiment, the operating element comprises an operating element controller configured to control the actuator of the tracking unit, wherein the operating element controller is configured to control the actuator to retain a current angular position of the neutral position of the finger input part upon release of the finger input part by the user (the steering angle that corresponds to the neutral position, to which the finger input part is restored upon release, may thus be maintained), or wherein the operating element controller is configured to control the actuator to change the angular position of the neutral position towards a default position upon release of the finger input part by the user (the neutral position, to which the finger input part is restored upon release, may thus be returned to the default position, and the wheels may thus be returned to a steering angle that corresponds to the default position, e.g. a zero angle). Whereas in the former case, the steering angle may be maintained at a position that corresponds to the angular position of the neutral position when the user releases the finger input part, in the latter case, the steering angle may be returned to a steering angle of zero degrees, e.g. a straight steering angle.

[0095] The operating element controller may be configured to use a predefined trajectory (e.g. change of angular position over time; such as a constant change of angular position over time) to return the neutral position to the default position. The steering wheels may thus smoothly be returned to their zero angle position (e.g. straight ahead position) upon release of the finger input part by the user. A more complex trajectory may also be employed.

[0096] The operating element controller may be configured to operate the operating element in a first operating mode in which a current angular position of the neutral position is retained upon release of the finger input part and to operate the operating element in a second operating mode in which the finger input part is returned to the default position

[0097] P25010PCT - Kahler Kdck Mollekopf - 92b581 a9-6304-4592-979c-2ff71 d383b4dupon release of the finger input part by the user. The operating element controller may be capable of switching between these operating modes, e.g. upon receipt of a user input or of a control signal, e.g. from a vehicle controller.

[0098] In any of the above embodiments, the operating element controller may be configured to receive the actual steering angle, e.g. from a steering controller of the vehicle, and to give out a signal indicating a target steering angle derived from an angular position of the finger input part, e.g. to a steering controller of the vehicle. The actual steering control may thus not be performed by the operating element controller. In other implementations, the operating element controller may form part of such steering controller.

[0099] In a particular embodiment, the finger input part may comprise a sensor configured to detect whether a user operates the operating element, e.g. a proximity sensor.

[0100] Additionally or alternatively, the detection whether a user operates the operating element may be based on at least one of a detection of a current of the actuator, of a position angle of the finger input part, and of a force / torque applied to the finger input part.

[0101] Preferably, the a finger input part is rotatable about only one rotation axis.

[0102] The operating element may not be a joystick having a joystick lever to be gripped by the user’s hand (i.e. the whole hand). Such joystick is not configured to be actuatable by a single finger.

[0103] The input part of the operating element may not have a gripping surface that allows gripping of the input part by a whole hand of the user. For example, the input part may be sized so small that it does not allow gripping by the user’s whole hand, e.g. sized so small that it does not fit the palm of a hand of the user (e.g. an adult male and / or female user).

[0104] The input part may be configured to be actuatable by only exactly one finger of the user. It may not be operable by more fingers. For example, the finger actuation surface may be so small that not more than one finger can engage or rest on the finger actuation surface. A particularly compact operating element may thereby be achieved.

[0105] P25010PCT - Kahler Kack Mollekopf - 92b581 a9-6304-4592-979c-2ff71 d383b4dAccording to another embodiment, an operating element for controlling the steering of a vehicle is provided. The operating element comprises a finger input part that is rotatable about a rotation axis. The finger input part is configured to be actuatable by only one finger or only two fingers of a user. It comprises a finger actuation surface configured to be engaged by the one or two fingers of the user to actuate the finger input part. The operating element further comprises a tracking unit for tracking an actual steering angle of the vehicle. The tracking unit comprises an actuator that is controllable to actively change a position of the finger input part based on the actual steering angle of the vehicle and / or that is controllable to actively change a force or torque applied to the finger input part based on the actual steering angle of the vehicle. It further comprises a sensor unit configured to detect at least one of an angular position of the finger input part and / or a force or torque applied to the finger input part for controlling the steering of the vehicle.

[0106] The operating element may have any of the configurations described above. In particular, any of the above-disclosed features may also be employed in any combination in the present embodiment of the operating element.

[0107] For example, the input part may be configured to be actuatable by only one finger selected from a thumb, an index finger, and a middle finger.

[0108] That the input part is actuatable by only two fingers may mean that not more than two fingers are needed to actuate the input part; the input part may also be operable with one finger. In another exemplary implementation, the input part may be configured to be actuatable by only exactly two fingers of a user, i.e. it may not be operable by fewer or more fingers.

[0109] For example, the finger actuation surface may be so small that not more than two fingers can engage / grip the input part.

[0110] As another example, the input part may be configured to be actuatable by only two fingers of a user, wherein the input part may be configured to be actuatable by two fingers gripping the input part and / or by the input part engaging a space between two adjacent fingers.

[0111] For example, the input part may be configured to be actuatable by gripping the input part with a thumb and an index finger, by gipping the input part with a thumb and a

[0112] P25010PCT - Kahler Kack Mollekopf - 92b581 a9-6304-4592-979c-2ff71 d383b4dmiddle finger, by the input part engaging a space between a thumb and an index finger (e.g. at the respective finger roots), and / or by the input part engaging a space between a thumb and a middle finger (e.g. at the respective finger roots).

[0113] According to another aspect of the invention, a steering control system for steering a vehicle, such as an off-highway vehicle, is provided. The vehicle may for example be an agricultural vehicle, construction vehicle, or an industrial vehicle. The steering control system comprises an operating element having any of the configurations described herein. The steering control system is configured to perform the steps of determining, based on an angular position of the finger input part and / or a force or torque applied to the finger input part (20) measured by the sensor unit, a control deflection for the finger input part; providing a control signal to control a steering system (e.g. steering angle) of the vehicle in accordance with the control deflection; obtaining from the steering system of the vehicle an actual steering angle; and controlling the tracking unit to actively change a position the finger input part based on the actual steering angle of the vehicle and / or to actively change a force or torque applied to the finger input part based on the actual steering angle of the vehicle. This may for example be performed to adjust the neutral position of the finger input part based on (e.g., proportional to) the actual steering angle. The steering angle may thereby be tracked by the neutral position. The steering control system may for example comprise the operating element controller having any of the above-described configurations, which may perform the respective steps.

[0114] The control deflection may correspond to the absolute deflection of the finger input part from the default position of the neutral position (zero steering angle), which can either be measured directly by the sensor unit (e.g. as the absolute angular position) or inferred from a measured relative deflection (e.g. angular position of finger input part relative to the neutral position).

[0115] It is remarked that the term absolute as used herein refers to the reference against which the angular position, e.g. the deflection, is measured but not to an absolute value in the mathematical sense. The deflection may occur in positive or negative direction., i.e. the angular position may have positive or negative values.

[0116] A target value for a steering angle of the vehicle may thus be set by means of the absolute angular position of the finger input part. It is also possible that a steering angle

[0117] P25010PCT - Kahler Kack Mollekopf - 92b581 a9-6304-4592-979c-2ff71 d383b4dchange is determined by a change of the angular position of the finger input part relative to the neutral position.

[0118] The steering control system may have a processing unit (e.g. microprocessor) and a memory (e.g. RAM, ROM, flash memory, and / or hard disc drives, or the like). The memory may store control instructions which may cause the steering control system to perform any of the methods disclosed herein when executed by the processing unit. The control instructions may be provided on a volatile or non-volatile data carrier.

[0119] According to another aspect of the invention, a vehicle comprising a control element or a steering control system having any of the configurations described herein is provided.

[0120] The operating element may be mounted to an armrest of an operator seat of the vehicle, preferably by means of a support handle as described herein. For example, it may be mounted to the left armrest.

[0121] The vehicle may further comprise a steering wheel. A steering angle of the vehicle may be controllable by both the operating element and the steering wheel. A selection may toggle between these.

[0122] When the steering angle is controlled by the steering wheel, the tracking unit of the operating element may track the actual steering angle of the vehicle. In such configuration, the user / operator can easily change to controlling the steering by the finger, in particular the thumb, since the control element reflects the actual steering angle.

[0123] When the steering angle is controlled by the operating element, the steering wheel may not track the steering angle of the vehicle. This may facilitate the implementation of the operating element in the control system. Further, the vehicle operator may not be disturbed during operation by the constantly moving steering wheel.

[0124] According to a further aspect of the invention, a method of controlling a steering system of a vehicle by means of an operating element having any of the configurations described herein is provided. The method comprises determining, based on an angular position of the finger input part and / or a force or torque applied to the finger input part (20) measured by the sensor unit, a control deflection for the finger input part; providing a control signal to control the steering system (e.g. steering angle) of the vehicle in

[0125] P25010PCT - Kahler Kdck Mollekopf - 92b581 a9-6304-4592-979c-2ff71 d383b4daccordance with the control deflection; obtaining from the steering system of the vehicle an actual steering angle; and controlling the tracking unit to actively change a position the finger input part based on the actual steering angle of the vehicle and / or to actively change a force or torque applied to the finger input part based on the actual steering angle of the vehicle. This may for example be performed to adjust the neutral position of the finger input part based on (e.g. proportional to) the actual steering angle.

[0126] The method may further comprise any of the steps disclosed herein with respect to the operating element, the steering control system, or the vehicle. Further, the operating element, the steering control system, or the vehicle may be configured to carry out any of the methods disclosed herein.

[0127] It is to be understood that the features mentioned above and those yet to be explained below can be used not only in the respective combinations indicated, but also in other combinations or in isolation, without leaving the scope of the present invention. In particular, the features of the different aspects and embodiments of the invention can be combined with each other unless noted to the contrary.

[0128] BRIEF DESCRIPTION OF THE DRAWINGS

[0129] The foregoing and other features and advantages of the invention will become further apparent from the following detailed description read in conjunction with the accompanying drawings. In the drawings, like reference numerals refer to like elements.

[0130] Fig. 1 is a schematic drawing showing an operating element and a steering control system according to an embodiment.

[0131] Fig. 2 is a schematic drawing showing an operating element according to an embodiment.

[0132] Fig. 3 is a schematic drawing showing angular ranges of an operating element according to an embodiment.

[0133] Fig. 4 is a schematic drawing showing an example of a mounting position of a thumb input part on a support handle of an operating element according to an embodiment.

[0134] P25010PCT - Kahler Kdck Mollekopf - 92b581 a9-6304-4592-979c-2ff71 d383b4dFigs. 5a-c are schematic drawings showing different deflections of an operating element according to an embodiment.

[0135] Fig. 6 is a schematic drawing showing an explosive view of an operating element according to an embodiment.

[0136] Fig. 7 is a schematic flow diagram illustrating a method according to an embodiment.

[0137] DETAILED DESCRIPTION

[0138] In the following, embodiments of the invention will be described in detail with reference to the accompanying drawings. It is to be understood that the following description of the embodiments is given only for the purpose of illustration and is not to be taken in a limiting sense. It should be noted that the drawings are to be regarded as being schematic representations only, and elements in the drawings are not necessarily to scale with each other. Rather, the representation of the various elements is chosen such that their function and general purpose become apparent to a person skilled in the art. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted.

[0139] Figure 1 schematically illustrates an operating element 10 according to an embodiment, which may form part of a steering control system 100 according to an embodiment. In the following description, the finger input part is provided by a thumb input part that is controllable by only the thumb of the user. The description is likewise applicable to an operating element having a finger input part configured to be controllable by one other finger of the user’s hand, such as by an index finger or middle finger. The finger input part of such control element may for example have an abutment surface or gripping surface as an actuation surface for the finger so that by, e.g. pushing with the finger against the surface, the finger input part is actuated. Such finger actuation surface can for example be provided in form of a rest for the respective finger (e.g. the below-described thumb rest or another surface on which the finger can rest, such as a top surface of a small lever), or can be provided, e.g., as a surface of a (e.g. miniature) switch or lever on which the finger can push.

[0140] P25010PCT - Kahler Kack Mollekopf - 92b581 a9-6304-4592-979c-2ff71 d383b4dIn the exemplary embodiment of Fig. 1, the operating element comprises a thumb input part 20 that is operable by a thumb of a user, e.g. by the vehicle operator. The thumb input part 20 may be supported by a housing 70. Optionally, the operating element 10 may comprise a support handle 90 to which the thumb input part 20 and its housing may be mounted. The support handle 90 may comprise a gripping area 91 in which the user’s hand can grip the handle 90. The thumb input part 20 is arranged next to the gripping area 91 such that the user’s thump can reach the thumb input part 20 and operate it over its full range when firmly gripping handle 90. The support handle 90 further includes a mounting base 92, by means of which it is mountable to a vehicle, such as to an armrest of an operator seat or to a dashboard or control panel. The part of handle 90 that includes the gripping area 91 is fixed relative to the mounting base 92 so that the handle 90 provides firm support for the user’s hand. Support handle 90 may be formed, e.g. cast, as a single piece.

[0141] The support handle 90 may comprise further control elements (not shown) for controlling different functions of the vehicle. As the handle is fixed, control of the thumb input part 20 is facilitated, and such additional control elements may likewise be controlled more ergonomically due to the firm support of the hand. Further, strain on the hand and in particular on the wrist may be reduced if the handle 90 is fixed in place, e.g. on an armrest. It is noted that in figure 1, for the purpose of illustration, the thumb input part 20 is shown so as to be operable in up / down direction. Preferably, when arranged ion the handle 90, the thumb input part 20 is rotated by 90 degrees compared to the illustration in figure 1, so that the user can actuate the thumb input part 20 in left / right direction. A more intuitive control of the steering of the vehicle may thereby be achieved.

[0142] An operating element controller 11 may control the function of the operating element 10. It may for example obtain a sensor signal indicative of a deflection of the thumb input part 20, in particular an angular position, and it may control a feedback mechanism of the operating element 10, such as the tracking unit described in more detail further below. The operating element controller 11 may pass on the detected angular position (e.g. deflection angle) or a control signal derived therefrom, such as a target steering angle, to the steering controller 110 of the vehicle 200. Steering controller 110 may form part of a steering system of the vehicle 200. Steering controller 110 may comprise a steering drive that adjusts a steering angle y of the wheels 201 of the vehicle 200 based on the control signal received from the operating element controller 11. The steering controller 110 may further comprise a steering angle sensor

[0143] P25010PCT - Kahler Kack Mollekopf - 92b581 a9-6304-4592-979c-2ff71 d383b4d112 for measuring the current steering angle y of the wheels 201 and may provide a respective signal indicating the actual steering angle to the operating element controller 11. The operating element controller 11 may then control the feedback mechanism of the operating element 10 in accordance with the received actual steering angle, e.g. by tracking the steering angle with a respective tracking unit.

[0144] An operating element 10 may thus be provided that allows a precise and intuitive control of the steering angle y of the vehicle 200. The operating element may not suffer from the drawbacks experienced when using a conventional joystick control for steering, such as wrist strain, accidental actuation by bumping etc., and a rather bulky appearance. In view of the compactness and reduced number and size of movable parts, the operating element 10 may be less expensive than conventional steering control elements.

[0145] Figure 2 schematically shows an exemplary implementation of the operating element 10 of figure 1. The thumb input part 20 has a thumb rest 21 that is concavely shaped and configured to receive the user’s thumb. It further comprises a support part 22 with a mounting part 23 to which the thumb rest 21 is mounted. The thumb input part 20 is supported rotatably about the rotation axis 15. By moving the thumb, the user can thus deflect the thumb input part 20 by a deflection angle about the rotation axis 15. The operating element comprises the sensor unit 60 that is configured to detect a respective deflection of the thumb input part 20, e.g. by detecting an angular position about the axis 15. This may occur optically (e.g. optical encoder), electrically (e.g. potentiometer or electrical encoder) and / or magnetically (e.g. permanent magnet and magnet sensor).

[0146] The thumb input part 20 has a neutral position 80 (figure 3) to which the thumb input part 20 is returned after release by the user. A restoring unit 50 is provided that applies a restoring torque to the thumb input part 20 upon deflection from the neutral position 80. Thus, when operating the thumb input part 20, the user needs to overcome the restoring torque, which provides feedback on that the user is changing the steering angle with the deflection. The restoring unit 50 may for example comprise springs 51 that bear against seats 27 of the thumb input part 20. The restoring unit 50 keeps the thumb input part 20 in the neutral position 80 when no force / torque is applied by the user, i.e. the thumb input part 20 returns to the neutral position 80 by effect of the spring force. A single spring 51 may alternatively be provided.

[0147] P25010PCT - Kahler Kack Mollekopf - 92b581 a9-6304-4592-979c-2ff71 d383b4dTo provide feedback on the current steering angle of the vehicle 200, the operating element 10 comprises the tracking unit 30 that changes the angular position of the neutral position 80 in accordance with the actual steering angle, e.g. a received signal indicative of the actual steering angle. The tracking unit 30 comprises the actuator 40 that rotates the neutral position 80, preferably but not necessarily about the same rotational axis 15. The tracking unit 30 further comprises the base part 31, which may be a separate piece or may form part of the actuator 40. The base part 31 has one or more seats 32 against which the one or more springs 51 bear. Accordingly, when the actuator 40, e.g. an electric motor, rotates the base part 31, the equilibrium position of the thumb input part 20 changes in angular direction, since the angular position of the spring seat(s) on the base part is changed.

[0148] In the exemplary embodiment of figure 2, a compact configuration can be achieved since the actuator 40, the base part 31 and the thumb input part 20 rotate about the same rotational axis 15 and no intervening transmission mechanism, e.g. gearbox, is provided. Compactness is further achieved by the fact that the operating element 10 is actuated by the user’s thumb, which allows the use of smaller parts and as smaller actuator 40 in view of the relatively low forces applied by a thumb.

[0149] Besides the torque of restoring unit 50 that acts on the thumb input part 20 upon deflection from neutral position 80, the thumb input part 20 may be supported freely rotatably by the housing 70, the base 31 and / or the actuator 40.

[0150] Figure 3 schematically illustrates angular operating ranges of the operating element 10, which may be implemented in any of the embodiments disclosed herein. The base part 31, and thus the angular position of the neutral position 80, may be rotatable within an angular range a, as shown in figure 3. The tracking unit 30 may track the steering of the vehicle within this tracking angle range a. Accordingly, the angular range a may be chosen to correspond to the range of the steering angle y. Thus, the neutral position may be rotatable to reflect each actual steering angle y.

[0151] The operating element 10 may be configured such that the steering via thumb input part 20 can still be performed reliably even if the tracking unit 30 becomes inoperative, e.g. due to a jamming of the actuator 40 or the like. For this purpose, the thumb input part 20 may be configured to be deflectable within a deflection angle range P, which is chosen such that even if the neutral position 80 is displaced to a border of the tracking angle range a (maximum tracking angle in positive or negative direction), the thumb

[0152] P25010PCT - Kahler Kack Mollekopf - 92b581 a9-6304-4592-979c-2ff71 d383b4dinput part 20 is deflectable from the neutral position within a deflection angle range that comprises the range of deflection angles that correspond to a full steering angle range of the vehicle.

[0153] Referring to figure 3, the full steering angle range may match with the tracking angle range a, as explained above. The deflection angle range P for the thumb input part 20 is chosen twice the size of the tracking angle range a. Accordingly, even if the neutral position 80 is moved to, e.g., the left hand border of the tracking angle range a by action of the actuator 40 (motor M, as indicated by arrows), and the deflection angle range P is thus rotated correspondingly, the right hand border of the deflection angle range P will coincide with the right hand border of the tracking angle range a. Even if the tracking unit becomes stuck, the thumb input part 20 can still be moved across the full tracking angle range a that corresponds to the full range of the steering angle y. Therefore, by configuring the deflection angle range P about the neutral position at least twice the size of the tracking angle range a, the functionality of the operating element 10 may be ensured and reliability may be improved.

[0154] Figures 5a-5c illustrate the operation of the operating element 10. Figure 5a shows a steering angle y of zero degrees, so that the wheels are not turned. The neutral position 80 is centered at the default position 85 that corresponds to the zero degree steering angle. In particular, the base part 31 that defines the neutral position is positioned at a default angle corresponding to the default position 85.

[0155] In figure 5b, an operation of operating element 10 occurs. The respective operating method is illustrated in the flow diagram of figure 7. In step S10, the thumb input part 20 is actuated by the thumb of the user. As shown in figure 5b, the thumb input part 20 is thus deflected about rotation axis 15 to an angular position 86. The arrow in figure 5b indicates the application of a respective force or torque to the thumb neutral of the thumb input part 20 by the user.

[0156] The deflection to the angular position 86 (e.g. the deflection angle) may be sensed by the sensor unit 60 of the operating element 10 (step SI 1). In response, a control signal is provided to the steering controller 110 to adjust the steering angle of the vehicle based on the sensed angular position in step S12. For example, the operating element controller 11 may provide the detected angular position or a signal derived therefrom to the steering controller 110. The operating element controller 11 may for example convert the detected angular position into a steering angle reference. Such signal or

[0157] P25010PCT - Kahler Kack Mollekopf - 92b581 a9-6304-4592-979c-2ff71 d383b4dreference may then be received by the steering controller 110, which may use it to operate the steering drive 111 to set the requested steering angle by turning wheels 201.

[0158] The steering controller 110 may further measure the actual steering angle y by means of the steering angle sensor 112 and may provide a respective measurement signal to the operating element controller 11. In step SI 3, the operating element controller 11 receives the actual steering angle. The operating element controller 11 may then in step S14 operate the tracking unit 30 to adjust the neutral position 80 in accordance with the actual steering angle. It may for example send a drive signal to the actuator 40 to rotate the base part 31. The base part and the neutral position 80 may thus be rotated to an angular position that corresponds to the actual steering angle y.

[0159] This is illustrated in figure 5c, wherein the base part 31 and the neutral position 80 have been rotated by an angle so that they correspond to the angular position 86 of the thumb input part 20. This position is reached upon the actual steering angle corresponding to the steering angle reference (i.e. the command) as input by the user via the deflection of thumb input part 20. Therefore, the restoring torque experience by the user reduces gradually until the neutral position 80 reaches the angular position 86. Torque feedback on the actual steering angle is thereby provided. Further, figure 5c shows that the wheels 201 have been turned to the steering angle y, which corresponds to the angular position 86.

[0160] It is noted that although the controllers 11 and 110 are shown as separate controllers, they may be integrated in a single controller or may be distributed to further controllers. Further, controller 11 may form part of the operating element 10. It may be physically separate from or may be integrated within the thumb operating element (thumb input part 20 and housing 70), or within the support handle 90.

[0161] Figures 4 and 6 show a particular implementation of the operating element 10 explained above. The above explanations are thus equally applicable to the embodiments of figures 4 and 6.

[0162] Turning to figure 6, the tracking unit 30 comprises the actuator 40 in form of an electric motor having a cylindrical shape. The motor may be a single axis gimbal motor, or a stepper motor, preferably with high angular resolution. A brushless DC motor is preferred. To properly adjust the position of the motor 40 to the desired angular position, a tracking position detector 45 is provided that tracks the position of the

[0163] P25010PCT - Kahler Kack Mollekopf - 92b581 a9-6304-4592-979c-2ff71 d383b4dactuator 40 (the motor), the base 30, and / or the neutral position 80. In the present example, the tracking position detector 45 detects the angular position of the actuator 40. As the base part 31 is fixedly mounted to an output of the actuator 40 and defines the neutral position 80, the angular position of the actuator 40 directly indicates the angular position of the base part 31 and of the neutral position 80. However, these may alternatively be detected directly. The tracking position detector 45 is implemented as an encoder that detects the angular position of a rotary output of the actuator 40, i.e. the electric motor. By using feedback control via the tracking position detector 45, the angular position of the motor output can be set precisely, in particular so as to correspond to an actual detected steering angle. The actuator 40 has in the present example an output in form of the output disc 41 that is rotated by the motor.

[0164] The base part 31 is directly mounted, e.g. screwed, to the output of the actuator 40, e.g. to the output disc 41. Thus, a compact configuration with a reduced number of parts may be achieved. Further, the angular position of the base part 31 may be controlled precisely without intervening transmission mechanism.

[0165] The base part 31 has the shape of a disc section. The shape is adapted to the output disc 41 of the actuator 40, resulting in a compact configuration. Further, the base part has two seats 32 for one or two springs 51 of the restoring unit 50 for defining the neutral position. As shown, the disc section may be an annular section that extends at least between the two spring seats 32.

[0166] The thumb input part 20 is configured as a thumbwheel that comprises a thumbwheel cap 25. The thumb rest 21 is provided on the thumbwheel cap 25 and is shaped concavely to receive a user’s thumb.

[0167] The thumb input part 20 is adapted to the shape of the actuator 40 (which may have a cylindrical shape) and optionally of the tracking position detector 45 (which may have a cylindrical shape). A part of the thumb input part 20, in particular the thumbwheel cap 25, may extend partially around the actuator 40 and the tracking position detector 45. for example, the thumbwheel cap 25 may have an inner surface that faces the actuator 40 and that is adapted to the shape of the actuator 40, and optionally the tracking position detector 45. It may have a complementary cylindrical shape. The thumbwheel cap 25 may for example comprise a section of a cylinder jacket, as shown in figure 6, and parts of the axial cylinder faces. This may provide a shape that allows a very compact configuration, since the thumbwheel cap 25 may closely extend around the

[0168] P25010PCT - Kahler Kack Mollekopf - 92b581 a9-6304-4592-979c-2ff71 d383b4dactuator 40. Due to the cylindrical shape, if the thumb input part 20 is rotated about axis 15, the thumbwheel cap 25 can rotate around the cylinder shape of actuator 40 and optionally of tracking position detector 45. Thumbwheel cap 25 and thumb rest 31 may be formed as a single piece.

[0169] The thumb input part 20 may further comprise the support part 22, which comprises a mounting part (or lever) 23 to which the thumb rest 21, in particular the thumbwheel cap 25 is mounted, for example via a snap fit. In other implementations, the support part 22 and the thumbwheel cap 25 may be formed as a single piece.

[0170] The support part 22 further comprises a shaft section 28 by means of which it is supported rotationally about the rotation axis 15. In the present example, the shaft section 25 engages a recess in the output (e.g. in output disc 41) of the actuator 40; it may be freely rotatable therein. In other implementations, the shaft section 28 may engage a respective recess in the housing 70. In even other implementations, the output of actuator 40 or the housing 70 may comprise a respective shaft section on which the support part 22 is rotationally support via a respective recess.

[0171] The support part 22 is further configured to support one or more springs of the restoring unit 50. It may comprise a spring support 26 configured to receive the coil of a torsion spring (e.g. centered on rotation axis 15) and one, two, or more spring seats 27. The spring seats are arranged such that when the support part is rotated in one direction, one spring seat takes along the spring (e.g. spring leg) to tension the spring and to create a restoring torque towards the neutral position, as defined by the base part 31.

[0172] In the example of figure 6, the restoring unit 50 comprises a single double torsion spring 51 the helical part of which is supported by the spring support 26. The two legs of spring 51 are supported by two seats 32 on the base part 31 and two seats 27 on the thumbwheel part 20. The double torsion spring 51 can thus provide a restoring torque for both directions of angular deflection of the thumb input part 20. Compared to two separate springs, such double torsion spring may provide particular benefits regarding a symmetrical restoring torque and a well-defined equilibrium position, e.g. reduced center play about the neutral position. It may further be more compact and reduce the number of required parts, thereby facilitating manufacturing.

[0173] The sensor unit 60 comprises a permanent magnet 61 positioned on the thumb input part 20, in particular mounted to the support part 22. Support part 22 may have a respective

[0174] P25010PCT - Kahler Kack Mollekopf - 92b581 a9-6304-4592-979c-2ff71 d383b4dmounting seat. To detect the rotation of permanent magnet 61 with the thumb input part 20, the sensor unit 60 comprises the Hall sensor 62, which can, e.g., detect the rotation and / or translation of the magnetic field. The sensor unit 60 may thereby provide a compact angle sensor which may precisely and reliable detect a rotation angle of the thumb input part 20. As the Hall sensor 62 is mounted to the housing 70, the angle is detected as an absolute angle with respect to the housing. In other implementations, a relative angle between the base part 31 and the thumb input part 20 may be detected, from which such absolute angle may be derived (e.g. using information from encoder 45).

[0175] The Hall sensor 62 may be provided on a circuit board 75. The circuit board may be coupled to and in communication with the operating element controller 11. In other implementations, the operating element controller 11 may be provided on the circuit board 75.

[0176] The housing 70 may have a section the shape of which is adapted to the shape of the actuator 40, and optionally of the tracking position detector 45. It may for example have a complementary cylindrical shape. Thus, a compact configuration can be achieved. The housing may have a second section configured to carry the Hall sensor 62, for example adapted to carry the circuit board 75.

[0177] The housing may not fully enclose the actuator 40. Part of the actuator 40 may be enclosed by the thumb input part 20, e.g. by the thumbwheel cap 25 as shown in figure 6. A compact configuration can thereby be achieved. The thumbwheel cap may slide on the actuator 40 and / or on the housing 70, e.g. on an axial sidewall thereof (with respect to axis 15).

[0178] It is noted that the embodiment of figure 6 is only an exemplary implementation, and that the thumb actuated operating element 10 may have different shapes and configurations, as described herein.

[0179] The above description has been given with respect to an operating element 10 that comprises a restoring unit 50 and a base part 31, by means of which the thumb input part 20 is coupled to the actuator 40. In other embodiments, the restoring unit 50 and the base part 31 may not be present, but the thumb input part 20 may directly be connected to a rotational output of the actuator 40 so that it rotates with the actuator 40. In such configuration, the remaining explanations provided above apply correspondingly. In

[0180] P25010PCT - Kahler Kack Mollekopf - 92b581 a9-6304-4592-979c-2ff71 d383b4dparticular, the operating element of such embodiment may have a shape corresponding to that of figure 6, without out the restoring unit 50 and the base part 31, and optionally without either the encoder 45 or the angular position sensor 60, as they would both measure the angular position of the thumb input part 20.

[0181] Figure 4 illustrates a respective embodiment that corresponds to the embodiment of figure 2 but in which no restoring unit 50 and no base part 31 are provided. The operating element 10 may further comprise the operating element controller 11. The operating element controller 11 controls the actuator 40 so as to apply the restoring torque towards the neutral position 80. For this purpose, the operating element 10 comprises a force and / or torque sensor 63 configured to measure the force or torque applied by a user to the thumb input part 20. Sensor 63 may be provided in form of a strain gauge on the thumb input part 20, or in form of any other known and suitable force / torque sensor. Sensor 63 may form part of the sensor unit 60. The operating element controller 11 may implement a force control scheme that controls the torque applied by actuator 40 based on input from the sensor 63. Such schemes are generally known in the art and will thus not be explained in greater detail here. Active impedance control may in particular be employed. The restoring torque is controlled such that it acts towards the neutral position 80 and that no restoring torque acts on the thumb input part 20 in the neutral position 80 (which may thus correspond to a simulated equilibrium position). The angular position of the neutral position 80 can thus be set by the operating element controller 11. The operating element controller 11 my in particular control the angular position of the neutral position 80 in any of the ways disclosed herein.

[0182] The operating element 10 of figure 4 thus corresponds to the operating element 10 of figure 2, with the exception that the mechanical restoring system (restoring unit and base part) has been replaced with an electrical restoring system, which may be implemented electronically or in software by the operating element controller 11.

[0183] While specific embodiments are disclosed herein, various changes and modifications can be made without departing from the scope of the invention. The present embodiments are to be considered in all respects as illustrative and non-restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.

[0184] P25010PCT - Kahler Kack Mollekopf - 92b581 a9-6304-4592-979c-2ff71 d383b4dList of reference signs

[0185] 10 operating element

[0186] 11 operating element controller

[0187] 15 rotation axis

[0188] 20 thumb input part

[0189] 21 thumb rest

[0190] 22 support part

[0191] 23 mounting part / lever

[0192] 25 thumbwheel cap

[0193] 26 spring support

[0194] 27 spring seat

[0195] 28 shaft section

[0196] 30 tracking unit

[0197] 31 base part

[0198] 32 spring seat

[0199] 35 base part mount

[0200] 40 actuator

[0201] 41 output disc

[0202] 45 encoder

[0203] 50 restoring unit

[0204] 51 spring

[0205] 60 sensor unit

[0206] 61 permanent magnet

[0207] 62 Hall sensor

[0208] 63 force or torque sensor

[0209] 70 housing

[0210] 75 circuit board

[0211] 80 neutral position

[0212] 85 default position

[0213] 86 angular position of thumb input part 90 support handle

[0214] 91 gripping area

[0215] 92 mounting base

[0216] 93 operating element placement area 100 steering control system

[0217] 110 steering controller

[0218] P25010PCT - Kahler Kdck Mollekopf - 92b581 a9-6304-4592-979c-2ff71 d383b4dIll steering drive

[0219] 112 steering angle sensor 200 vehicle

[0220] 201 wheels

[0221] a tracking angle range P deflection angle range Y steering angle

[0222] M motor

[0223] S10-S14 method steps

[0224] P25010PCT - Kahler Kdck Mollekopf - 92b581 a9-6304-4592-979c-2ff71 d383b4d

Claims

CLAIMS:

1. An operating element for controlling a steering of a vehicle, wherein the operating element (10) comprises:a finger input part (20) that is rotatable about a rotation axis (15), wherein the finger input part (20) is configured to be actuatable by only one finger of a user and comprises a finger actuation surface (21) configured to be engaged by the finger of the user to actuate the finger input part;a tracking unit (30) for tracking an actual steering angle of the vehicle (200), wherein the tracking unit (30) comprises an actuator (40) that is controllable to actively change a position of the finger input part (20) based on the actual steering angle (y) of the vehicle (200) and / or that is controllable to actively change a force or torque applied to the finger input part (20) based on the actual steering angle (y) of the vehicle (200); anda sensor unit (60) configured to detect at least one of an angular position (86) of the finger input part (20) and / or a force or torque applied to the finger input part (20) for controlling the steering of the vehicle (200).

2. The operating element according to claim 1, wherein the finger input part is a thumb input part (20) configured to be actuatable by only a thumb of the user, wherein the thumb input part (20) comprises a thumb rest (21) configured to provide a rest for the thumb of the user, the thumb rest (21) providing the finger actuation surface.

3. The operating element according to claim 2, wherein the thumb rest (21) has a concavely shaped rest surface configured to provide a rest for the thumb of the user.P25010PCT - Kahler Kdck Mollekopf - 92b581 a9-6304-4592-979c-2ff71 d383b4d4. The operating element according to any of the preceding claims, wherein the actuator (40) is a motor having a rotation axis, wherein the rotation axis of the motor is parallel to or coincides with the rotation axis (15) of the finger input part (20).

5. The operating element according to any of the preceding claims, wherein the finger input part (20) has a neutral position (80) from which it is deflectable, wherein the actuator (40) is controllable to actively change the neutral position (80) of the finger input part (20) based on the actual steering angle of the vehicle (200).

6. The operating element according to any of the preceding claims, wherein the tracking unit (30) comprises a restoring unit (50) configured to restore an angular deflection of the finger input part (20) to the neutral position (80) and further comprises a base part (31) that is rotatable about a base part rotation axis, wherein the base part (31) defines the neutral position (80) of the restoring unit (50) so that the neutral position is angularly displaced about the base part rotation axis if the base part is rotated, and wherein the actuator (40) is mechanically coupled to the base part (31) to rotate the base part (31).

7. The operating element according to claim 6, wherein the actuator (40) is directly mechanically connected to the base part (31) without an intervening transmission mechanism, wherein preferably, the actuator (40) is a motor and the base part (31) is directly connected to a rotational output (41) of the motor to rotate with the rotational output.

8. The operating element according to any of claims 6-7, wherein the restoring unit (50) comprises at least one spring (51) configured to generate a restoring torque for returning the finger input part (20) to the neutral position (80), wherein the at least one spring (51) is preferably arranged to act between the finger input part (20) and a base part (31) of the tracking unit (30), wherein more preferably, the at least one spring (51) is a double torsion spring, wherein each leg of the double torsion spring (51) rest on a respective seat (32) of the base part (31).P25010PCT - Kahler Kdck Mollekopf - 92b581 a9-6304-4592-979c-2ff71 d383b4d9. The operating element according to any of the preceding claims, wherein the actuator (40) is mechanically coupled to the finger input part (20) to directly rotate the finger input part about the rotation axis (15), wherein the operating element comprises an operating element controller (11) configured to control the actuator of the tracking unit, wherein the operating element controller (11) is configured to control the actuator to apply a restoring torque to the finger input part (20) towards a neutral position (80) of the finger input part (20) upon an angular deflection of the finger input part (20) from the neutral position (80), wherein the controller is preferably further configured to control the actuator (40) to actively change the neutral position (80) of the finger input part (20) based on the actual steering angle of the vehicle (200).

10. The operating element according to any of the preceding claims when dependent on claim 5, wherein the operating element comprises an or the operating element controller configured to control the actuator of the tracking unit, wherein the operating element controller is configured to operate the operating element in a first operating mode in which it controls the actuator to retain a current angular position of the neutral position of the finger input part upon release of the thumb input part by a user, and / or to operate the operating element in a second operating mode in which it controls the actuator to change the angular position of the neutral position towards a default position upon release of the finger input part by a user, wherein the default position preferably corresponds to a zero degree steering angle.

11. The operating element according to any of the preceding claims, wherein the finger input part (20) comprises a fingerwheel cap, in particular a thumbwheel cap (25), and a support part (22), wherein the support part (22) is rotationally supported and comprises a mounting part (23) extending in radial direction from the rotation axis (15), wherein the fingerwheel cap is mounted to or formed integrally with the mounting part (23).

12. The operating element according to claim 11, wherein the support part (22) is positioned in a direction of an actuator rotation axis adjacent to an actuator output (41), and wherein the fingerwheel cap is arranged in a radial direction perpendicular to theP25010PCT - Kahler Kdck Mollekopf - 92b581 a9-6304-4592-979c-2ff71 d383b4dactuator rotation axis outwardly adjacent to the actuator (40) and extends in the direction of the actuator rotation axis over the actuator (40) and the mounting part (23).

13. The operating element according to any of the preceding claims, wherein the finger input part (20) extends in a rotation direction about the rotation axis (15) partially around the actuator (40) of the tracking unit (30).

14. The operating element according to any of the preceding claims, wherein the sensor unit (60) comprises a permanent magnet (61) mounted to the finger input part (20) and a Hall sensor (62) arranged to detect a change of a magnetic field generated by the permanent magnet (61) upon rotation of the finger input part (20), wherein the Hall sensor (62) is preferably mounted to a housing (70) of the operating element (10).

15. The operating element according to any of the preceding claims, further comprising a support handle (90) configured to be mounted to the vehicle (200), wherein the finger input part (20) is mounted to the support handle (90), wherein the support handle is fixed or is deflectable about one or more degrees of freedom, wherein preferably, the operating element comprises one or more sensing elements arranged to detect the deflection of the support handle (90) in the one or more degrees of freedom and is configured to provide an output signal based on the detected deflection for controlling a function of the vehicle.

16. A steering control system for steering a vehicle, wherein the steering control system (100) comprises an operating element (10) according to any of the preceding claims, wherein the steering control system (100) is configured to perform the steps of:determining, based on an angular position of the finger input part (20) and / or a force or torque applied to the finger input part (20) measured by the sensor unit (60), a control deflection for the finger input part (20);providing a control signal to control a steering system (110) of the vehicle (200) in accordance with the control deflection;obtaining from the steering system (110) of the vehicle (200) an actual steering angle (y); andP25010PCT - Kahler Kdck Mollekopf - 92b581 a9-6304-4592-979c-2ff71 d383b4dcontrolling the tracking unit (30) to actively change a position the finger input part (20) based on the actual steering angle (y) of the vehicle (200) and / or to actively change a force or torque applied to the finger input part (20) based on the actual steering angle (y) of the vehicle.

17. A method of controlling a steering system of a vehicle by means of an operating element according to any of claims 1-15, wherein the method comprises:determining, based on an angular position of the finger input part (20) and / or a force or torque applied to the finger input part (20) measured by the sensor unit (60), a control deflection for the finger input part (20);providing a control signal to control the steering system (110) of the vehicle (200) in accordance with the control deflection;obtaining from the steering system (110) of the vehicle (200) an actual steering angle (y); and- controlling the tracking unit (30) to actively change a position the finger input part (20) based on the actual steering angle (y) of the vehicle (200) and / or to actively change a force or torque applied to the finger input part (20) based on the actual steering angle (y) of the vehicle.P25010PCT - Kahler Kdck Mollekopf - 92b581 a9-6304-4592-979c-2ff71 d383b4d

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