The present invention relates to a rotary knob control assem ^¬ bly for a motor vehicle including a rotary knob, an optical indicator associated with the rotary knob, and an adaptive brake mechanism capable of acting on the rotary knob to selec ^¬ tively increase resistance against movement of the rotary knob. The rotary knob control assembly further comprises a control unit connected to the optical indicator, to a sensor for sensing rotational movements of the rotary knob, to the adaptive brake mechanism, and to vehicle devices to be con ^¬ trolled by the control unit. The control unit has a memory in which position patterns of the rotary knob are stored for the vehicle devices. Each position pattern comprises a number of rotary knob positions each of which is associated with a com ^¬ mand for a vehicle device and with an indication symbol for the command. The control unit is arranged, when a particular position pattern is selected, to receive information from the sensor of rotational movements, and to control the adaptive brake mechanism to generate a detent-like haptic perception if the rotary knob reaches one of the stored rotary knob posi ^¬ tions .

Rotary knob control assemblies are for example used in motor vehicles in order to control different functions such as the functions of a navigation system or a radio.

Such a rotary knob control assembly is disclosed in DE 100 29 191 Al which forms the basis for the preamble of claim 1. The rotary knob control assembly comprises a rotary knob, having a magnetic circuit and at least one coil. The rotary knob is supported so as to be rotatable with respect to at least a part of the magnetic circuit, the gap present between the ro ^¬ tary knob and the magnetic circuit is filled with a magneto- rheological fluid, and the coil is arranged to exert a varia ^¬ ble braking action on the rotary knob. The control element is particular suitable for controlling functions in the cockpit of automobiles or other means of a conveyance. It can be used for example to control functions of a navigation device. The handling of different vehicle devices each comprising a lot of different functions using one control element is confusing for the driver.

Nowadays more and more functions are controlled electronically in motor vehicles such as the shift-by-wire system which ena ^¬ bles electronically controlled gearshifts of an automated gearbox. As another example ignition systems are handled elec ^¬ tronically using a button to start the motor vehicle. Although the key is provided to assure that it is kept by the driver as an identification or an authentication means and located within the vehicle when the driver starts to drive there is in a technical sense no need for a key.

The use of electronics within the motor vehicle allows not on ^¬ ly to remove e.g. the traditional, manual parking brakes and replace these by electrical parking brakes but also, in some vehicles, to remove the possibility for the driver to manually engage the electrical parking brake or the park mode function of a gearbox. The latter can create confusion of whether the gearbox is in the park mode.

The advancements of electronics have led to reduction in costs (fewer and smaller parts) and gaining more space in the cockpit. Yet no solutions have so far been provided to collective ^¬ ly take advantage of all these advancements. That is, the me ^¬ chanical ignition key has been reduced to a button and the me ^¬ chanical park brake has been reduced to a small switch or has been removed completely. The latter leads to issues relating to driver comfort and safety. Thus, there is a need to contin ^¬ ue smarter Human-Machine-Interface-solutions (HMI solutions) without compromising intuitive and save HMI and user experi ^¬ ence design. Especially with advancements of other market driven needs within HMI, such as the trends of larger infotainment screens, there is a need to take advantage of a ho ^¬ listic approach between different functional devices.

Therefore, it is an object of the present invention to provide a rotary knob control assembly for a motor vehicle which al ^¬ lows a more efficient handling of multiple vehicle devices without compromising user experience and safety.

This object is achieved by a rotary knob control assembly com ^¬ prising the features of claim 1. Preferred embodiments are set out in the dependent claims.

According to the present invention a first vehicle device is an engine and a second vehicle device is a gearbox. Further ^¬ more the control unit is arranged to select a first position pattern for engine start upon activation of the rotary knob control assembly and to subsequently control the optical indi ^¬ cator such that at least one indication symbol is shown at a stored rotary knob position which is associated with a start ^¬ ing command for the engine. The control unit is further ar ^¬ ranged to control the engine such that it executes the start ^¬ ing command for the engine when the rotary knob is rotated in the corresponding rotary knob position and to select a second position pattern for the gearbox upon receiving information from the engine that it is running. The control unit is fur ^¬ ther arranged to subsequently control the optical indicator such that indication symbols are shown at the stored rotary knob positions corresponding to different states of a second vehicle device (P, R, N and D of the gearbox) and to assign the current position of the rotary knob to the park mode of the gearbox. In general it is most likely that when activating the rotary knob control assembly the vehicle is in a parking position. Consequently the gearbox is in a park mode.

The control unit may be connected to sensors which sense the current state of the gearbox and send corresponding data to the control unit. According to the present invention the term "states" of a gearbox has to be understood as the different modes of the gearbox such as park, reverse, neutral or drive.

The rotary knob control assembly is fully integrated into the operating system of the vehicle. It allows flexible use of the rotary knob as a control element to control different func ^¬ tions of the vehicle. As the control unit is arranged to com ^¬ municate not only with the rotary knob and the optical indica ^¬ tor but also with the engine or gearbox it is possible to au ^¬ tomatically switch between the handling of the two vehicle de ^¬ vices. If an input to any of the vehicle devices is needed from the driver the corresponding position pattern of the engine or the gearbox may be automatically selected such that a user is for example directly able to execute a command using the rotary knob.

According to the present invention the term "detent-like hap- tic perception" has to be understood as to cover any force path which is perceived as a detent or temporarily fixation of the rotary knob.

In a preferred embodiment the rotary knob control assembly is activated when the motor vehicle is in an operable state. Such an operable state may be reached for example upon switching on ignition by inserting or turning the car key into or in the ignition lock. In the operable state the vehicle devices are provided with electrical energy. The car is ready to be start- ed but the engine is turned off. Alternatively the motor vehi ^¬ cle may be brought into an operable state when the vehicle de ^¬ tects that the driver is about to start the car. For example if the motor vehicle allows a "keyless" handling such as the driver does not have to insert or turn the car key into or in the ignition lock in order to start the car, activation of the rotary knob control assembly may occur when the driver ap ^¬ proaches the vehicle or is seated in the driver's seat.

In an alternative embodiment the optical indicator is a dis ^¬ play and/or the indication symbol is a display symbol. Prefer ^¬ ably the display is located close to the rotary knob. Variable display symbols e.g. single letters but also words or graph ^¬ ical elements such as lines or arrows may be visualized. It has to be understood that the rotary knob control assembly may also use any display of the motor vehicle provided to visual ^¬ ize the functions of other systems such as the navigation sys ^¬ tem or the radio.

Advantageously a first direction of rotation of the rotary knob in order to execute the starting command of the engine and a second direction of rotation of the rotary knob in order to switch the gearbox from the park mode to any other state is the same. Normally a motor vehicle is started in order to drive the car. Thus, having to turn the rotary knob to start the car and chose e.g. the drive mode of the gearbox in the same direction simplifies the handling of the motor vehicle.

Preferably the control unit is further arranged to select the second position pattern for the gearbox based on the angular velocity of the rotary knob. For safety reasons it may be pre ^¬ ferred that the driver is not able to start the engine and turn the gearbox into the drive mode with one single continu ^¬ ous movement of the rotary knob. A predefined angular velocity of the rotary knob may have been defined below which the se- cond position pattern is selected. Preferably the control unit is configured such that the position pattern of the engine will stay selected as long as the rotary knob is turned faster than the predefined velocity.

In order to enable such a feature the rotary knob may be de ^¬ signed as endlessly rotatable e.g. such that it can be turned in one direction until the predefined angular velocity is reached. Thus, the absolute positions of the rotary knob meas ^¬ ured in a locally fixed coordinate system change relative to the rotary knob positions contained in the position pattern and being associated with a command for the vehicle devices. In order to correlate the absolute positions of the rotary knob to the rotary knob positions contained in the position pattern the current, absolute position of the rotary knob is assigned to the park mode of the gearbox when the rotary knob reaches the predefined velocity and the second position pat ^¬ tern is selected. In order to switch from park mode to the drive mode the relative position of the rotary knob is meas ^¬ ured. Thus, the term "position" of the rotary knob refers to both the absolute and the relative positions of the rotary knob .

In an alternative embodiment it may very well be an intended feature of the device that the driver is able to start the en ^¬ gine and turn the gearbox into the drive mode with one single continuous movement of the rotary knob in order to start quickly. Safety could be established by managing the brake pe ^¬ dal sensor in a know fashion, e.g. that the brake pedal has to be pressed in order to switch into the drive mode.

In a preferred embodiment the control unit is further arranged to select the second position pattern for the gearbox if the angular speed of the rotary knob is zero. This is to force the driver to let go his/her hand of the rotary knob in order to avoid a selection of an undesired state of the gearbox by mis ^¬ take. This increases safety when operating the car.

In an alternative embodiment the second position pattern com ^¬ prises a rotary knob position associated with a stopping command for the engine. Preferably the rotary knob position asso ^¬ ciated with the stopping command is positioned next to the ro ^¬ tary knob position associated with the park mode of the gear ^¬ box and forms the outermost rotary knob position in the second position pattern. Thus, when parking the car the driver can easily switch from the drive mode into the park mode by turn ^¬ ing the rotary knob e.g. counterclockwise. When turning the rotary knob further it reaches its position associated with the stopping command for the engine. The control unit is ar ^¬ ranged to control the engine such that it executes the stop ^¬ ping command when the rotary knob is rotated in the corre ^¬ sponding rotary knob position such that the engine stops.

In an alternative arrangement the adapted brake mechanism uti ^¬ lizes a magneto-rheological fluid acting between a component moving with the rotary knob and a stationary component, where ^¬ in the adaptive brake mechanism is arranged to control a mag ^¬ netic field generator to generate a magnetic field in the area of the magneto-rheological fluid upon activation. Using the magneto-rheological fluid allows to define multiple rotary knob positions for different devices to be controlled by the rotary knob. Thus, it is possible to easily change these rota ^¬ ry knob positions when a position pattern of different vehicle devices is selected.

Advantageously the control unit may store resistance patterns of the rotary knob in the memory for the vehicle devices. The corresponding resistance pattern is selected by the control unit and the brake mechanism is controlled by the control unit accordingly. This allows to vary the resistance patterns de- pending on the vehicle device to be controlled by the control unit. E.g. the resistance pattern for the engine may differ from the resistance pattern for the gearbox. Preferably a re ^¬ sistance pattern may vary between the different states of the vehicle devices, e.g. between the park mode and the drive mode of the gearbox. If a position pattern comprises commands of two vehicle devices the corresponding resistance pattern may analogously vary between the commands of one single vehicle device as well as between the commands of different vehicle devices .

Moreover, engaging the park mode of the gearbox could be pro ^¬ grammed to require a higher torque and/or longer rotating dis ^¬ tance than going from the drive mode to the neutral mode. The same may apply for the switching from the park mode of the gearbox to the stopping command for the engine. Also, time variables could be implemented in addition to angular velocity and position and resistance: e.g. the rotary knob has to be pressed against the torque peak (i.e. at a certain position without overcoming the resistance force) for a certain time interval in order to switch between different states of the vehicle devices. This prevents the driver to accidentally turn the rotary knob form drive mode to park mode or worse from park mode to the stopping command for the engine.

Furthermore a variation of a resistance pattern may be speed dependent (less resistance at lower speeds, higher resistance at higher speeds) and could also be selected according to pre- stored profiles by the driver or set by the driver himself. Also both the resistance pattern for the engine and the gear ^¬ box could include pre-defined end-stop profiles to provide the sensation of an end stop when no further knob position is selectable in one turning direction. Also, sensory information from the brake pedal could be used in the controlling of the knob to further increase safety ac ^¬ cording to known regulations. For example when having selected the first position pattern the resistance pattern of the rota ^¬ ry knob could be set to provide maximum resistance (needing a high torque to rotate the knob at all) unless the brake is be ^¬ ing pressed. As known in the art, a visual/audio or haptic feedback could make the driver aware of the fact that the brake has to be pressed.

The invention will be described in the following connection with various examples of preferred arrangements in the draw ^¬ ings, in which

Fig. 1 shows a schematic block diagram of a rotary knob control assembly;

Fig. 2 shows a control element comprising a rotary knob;

Fig. 3 shows a rotary knob control assembly upon activation in a schematic view;

Fig. 4 shows a rotary knob control assembly after having se ^¬ lected a second position pattern for the gearbox in a schemat ^¬ ic view;

Figs. 5a to 5d show schematic views of a rotary knob control assembly according to a second embodiment in different states;

Fig. 6 shows an alternative state of the rotary knob control assembly to the one disclosed in figure 5d.

Fig. 1 shows a schematic block diagram of a rotary knob control assembly 1 for a motor vehicle. The rotary knob control assembly 1 comprises a control element 2 with a rotary knob 3 and an adaptive brake mechanism 4 capable of acting on the ro ^¬ tary knob 3 to selectively increase and/or decrease resistance against movement of the rotary knob 3. The control element 2 also comprises a sensor 5 for sensing rotational movements and/or an angular velocity of the rotary knob 3.

The rotary knob control assembly 1 further includes an optical indicator designed as a display 6 associated with the rotary knob 3 and a control unit 7 connected to the display 6, to the sensor 5, to the adaptive brake mechanism 4 and to vehicle de ^¬ vices 8, 9 to be controlled by the control unit 2. In the em ^¬ bodiment shown in Fig. 1 a first vehicle device is an engine 8 and a second vehicle device is a gearbox 9.

The control unit 7 comprises a memory 10 in which position patterns of the rotary knob 3 are stored for the engine 8 and the gearbox 9. Each position pattern comprises a number of ro ^¬ tary knob positions each of which is associated with a command for the engine 8 and/or the gearbox 9 and with an indication symbol for the command which is configured as a display sym ^¬ bol .

The control unit 7 is arranged, when a particular position pattern for the engine 8 or the gearbox 9 is selected, to re ^¬ ceive information from the sensor 5 of rotational movements and to control the adaptive brake mechanism 4 to generate a detent-like haptic perception if the rotary knob 3 reaches one of the stored rotary knob positions.

Fig. 2 shows a detailed view of the control element 2. The adaptive brake mechanism 4 utilizes a magneto-rheological flu ^¬ id 11 acting between a component 12 moving with the rotary knob 3 and a stationary component 13. The adaptive brake mech ^¬ anism 4 is arranged to control a magnetic field generator 14 such as a coil to generate a magnetic field in the area of the magneto-rheological fluid 11 upon activation. The rotary knob 3 is endlessly rotatable as there is no mechanical restriction which would limit the rotary knob 3 in its turning angle.

Fig. 3 shows the rotary knob control assembly 1 after being activated by bringing the motor vehicle into an operable state. In the operable state the vehicle devices are provided with electrical energy. The car is ready to be started but the engine is turned off.

The control unit 7 is arranged to select a first position pat ^¬ tern 15 for the engine 8 upon activation and to subsequently control the display 6 such that at least one display symbol 16 for the command is shown at a stored rotary knob position which is associated with a first command such as a starting command for the engine 8.

The control unit 2 is further arranged to control the engine 8 such that it executes the starting command when the rotary knob 3 is rotated in the corresponding rotary knob position. According to Fig. 3 the rotary knob 3 has to be turned clockwise as shown by the display symbol 16 to reach the corre ^¬ sponding rotary knob position.

As shown in Fig. 4 the control unit 7 is adapted to select a second position pattern 17 for the gearbox 9 upon receiving information from the engine 8 that it is running and is there ^¬ fore in an operating state. It may be required as a second op ^¬ tional requirement for the selection of the second position pattern 17 that the angular velocity of the rotary knob 3 af ^¬ ter being moved to the rotary knob position associated with the starting command of the engine 8 is zero. Thus, the con ^¬ trol unit 7 may be adapted accordingly to monitor the angular velocity of the rotary knob 3, to determine when the velocity is zero and to select the second position 17 pattern for the gearbox 9.

Moreover, the control unit 7 is arranged to subsequently con ^¬ trol the display 6 such that second display symbols 18 for the commands are shown at the stored rotary knob positions corre ^¬ sponding to different states of the gearbox 9.

During operation of the rotary knob assembly 1, e.g. when the rotary knob 3 is turned until the angular velocity is zero (see above) , the absolute position of the rotary knob 3 meas ^¬ ured in a locally fixed coordinate system (not shown) changes relative to the rotary knob positions contained in the posi ^¬ tion pattern 17 and being associated with a command for the vehicle devices 8, 9. Thus, in order to correlate the current position of the rotary knob 3 and the rotary knob positions contained in the position pattern 17 the control unit 7 is ar ^¬ ranged when selecting the second position pattern 17 and when the angular velocity of the rotary knob 3 is zero to assign the current, absolute position of the rotary knob 3 to the park mode of the gearbox 9.

In order to switch from park mode to the drive mode or any other state of the gearbox 9 the control unit 7 is arranged to monitor the relative position of the rotary knob 3 and thus identify if the current position of the rotary knob 3 matches a rotary knob position contained in the second position pat ^¬ tern 17.

The control unit 7 may be arranged to highlight the current state of the gearbox 9 such as the park mode, as shown in Fig. 4. Additionally, the control unit 7 may be adapted to control the display 6 to show a line which symbolizes the correspond ^¬ ence between the actual position of the rotary knob 3 and the assigned current state of the gearbox 9. Figures 5a to 5d show a second embodiment of the rotary knob control assembly 1 in different states. The rotary knob con ^¬ trol assembly 1' differs from the one shown in figures 3 and 4 by an optical indicator which is designed as a backlight 19. The backlight 19 is adapted to individually illuminate indica ^¬ tor symbols which are designed as graphics 20. These graphics 20 may be built from a sheet or a cover out of which single letters such as "P", "R", "N", "D", geometrical figures such as arrows, lines or complete words such as "Engine start" or "Engine stop" have been stamped out. The graphics 20 are posi ^¬ tioned along the outer cylindrical surface of the rotary knob 3.

In a radial direction further outward than the graphics "P", "R", "N", "D" there may be another graphic 20 designed as a curved line (figure 5b) . The line can also be backlit by the backlight 19 and corresponds to a graphic 20 designed as a "start" arrow and being associated with the starting command for the engine 8 (figure 1) . Close to the "start" arrow there is another graphic 20 designed as "stop" arrow which is asso ^¬ ciated with a stopping command for the engine 8 (figure 1) .

The backlight 19 is installed behind the graphics 20 in order to illuminate them when the rotary knob 3 is in the corre ^¬ sponding rotary knob position.

In the following the handling of the rotary knob control as ^¬ sembly 1 ' shall be described with reference to figures 5a to 5d. It has to be understood that the handling described in the following can be applied analogously to the rotary knob con ^¬ trol assembly 1 disclosed in figures 1 to 4.

Figure 5a shows the rotary knob control assembly 1 ' before ac ^¬ tivation. A resistance pattern of the rotary knob 3 has been chosen by the control unit 7 (figure 1) such that the rotary knob 3 is endlessly rotatable and only basic friction has to be overcome when rotating the rotary knob 3.

When the rotary knob control assembly 1 has been activated by e.g. bringing the motor vehicle into an operable state a first position pattern 21 is selected by the control unit 7 (figure 1) and the graphics 20 are controlled such that the "start" arrow is backlit as shown in figure 5b. As an optional feature the curved line positioned in a radial direction outward of the graphics "P", "R", "N", "D" may also be highlighted to ^¬ gether with the "start" arrow. The corresponding resistance pattern of the rotary knob 3 has been chosen by the control unit 7 (figure 1) such that a counterclockwise rotation is prohibited. The rotary knob 3 is endlessly rotatable in clock ^¬ wise direction without any detent haptic perception as long as the angular velocity of the knob is above zero. Turning the rotary knob 3 clockwise it reaches a stored rotary knob posi ^¬ tion associated with the starting command of the engine 8 (figure 1) which then will start.

Referring to figure 5c the engine 8 (figure 1) is running and the current position of the rotary knob 3 has been assigned to the park mode of the gearbox 9 (figure 1) . The control unit 7 (figure 1) has selected a second position pattern 22 and the graphic "P" as well as the "stop" arrow is illuminated by the backlight 19. The resistance pattern is chosen such that ro ^¬ tating the rotary knob 3 in a counterclockwise direction the driver perceives a haptic stop which can be overcome with con ^¬ siderable effort or which can be overcome after a predefined period of time. In clockwise direction the driver will feel free detents corresponding to the graphics "R", "N" and "D" with a maximum end stop after the graphic "D".

Turning to figure 5d the rotary knob 3 has been turned to graphic "D" and the control unit 7 (figure 1) controlled the gearbox 9 (figure 1) such that it is in its drive mode. The resistance pattern is chosen such that a haptic end stop for a clockwise rotation of the rotary knob 3 is perceived. Turning the rotary knob 3 counterclockwise will lead to a perception of free detents each of which corresponds to the graphics "P", "R" and "N" . Another haptic end stop in a counterclockwise turning direction will be perceived after the graphic "P".

If the driver has parked the motor vehicle and turned the ro ^¬ tary knob in a position corresponding to graphic "P" as shown in figure 5c the control unit 7 (figure 1) controls the gear ^¬ box 9 (figure 1) such that it is in its park mode. By turning the rotary knob counterclockwise towards to the "stop" arrow the rotary knob 3 is moved into a rotary knob position associ ^¬ ated with a stopping command for the engine 8 (figure 1) . The resistance pattern selected is the one described before with reference to figure 5c.

Figure 6 shows an alternative state of the rotary knob control assembly 1 ' to the one described with reference to figure 5d when having turned the rotary knob 3 in a rotary knob position associated with the drive mode of the gearbox 9 (figure 1) . Provided that the motor vehicle is driving faster than a pre ^¬ determined speed level (e.g. >8 km/h) the graphics "P" and "R" are backlit e.g. by a multicolored backlight 23 such that they are not recognized by the driver. Only the graphics "N" and "D" can be seen by the driver wherein graphic "D" is backlit as described with reference to figure 5d. The resistance pat ^¬ tern is chosen such that the driver perceives a haptic end stop for clockwise rotation and only one detent for counterclockwise rotation with an end stop directly after graphic "N" . This gives the impression that the "start" arrow or the "stop" arrow cannot be reached. List of reference signs

1' Rotary knob control assembly

Control element

Rotary knob

Brake mechanism

Sensor

Display

Control unit

Engine (vehicle device)

Gearbox (vehicle device)

Memory

Magneto-rheological fluid

Moving component

Stationary component

Magnetic field generator

, 21 First position pattern

, 22 First display symbol

Second position pattern

Second display symbol

Backlight

Graphic

Multicolored backlight