Patent Publication Number: US-2022223358-A1

Title: Control element

Description:
The invention relates to a control element used in a vehicle, in particular a motor vehicle, rail vehicle, aircraft or boat. 
     There are numerous control elements in vehicles that can easily distract an operator of the vehicle. These distractions can result in undesired reactions, or cause an accident. 
     Based on this, the fundamental object of the invention is to create a control element that distracts the user as little as possible. 
     This object is achieved by a control element comprising an electro-rheological material, which has at least one driver assembly for generating a variable electric field. 
     The object is achieved entirely in this manner. 
     According to the invention, a change in the feel of the control element can be generated by a change in the electric field. This can be obtained in particular through a change in the shape and/or texture of the control element. It is possible to communicate with the user of the control element in this manner, without the user having to actually look at the control element, thus forming a distraction. 
     According to another embodiment of the invention, the electro-rheological material contains an electro-rheological elastomer. 
     According to another embodiment of the invention, the electro-rheological material contains an electro-rheological liquid. 
     In both cases, the electro-rheological properties of the material can be used to change the properties of the electro-rheological material through the application an electric field. 
     If the elastomer is electro-rheological, it is an elastomer that can be polarized electrically. Some elastomers that can be polarized electrically, e.g. polyvinyl chloride, PVC. Other elastomers are difficult to polarize, e.g. styrol-rubber materials, e.g. SEBS, SIBS, SEPS. Polarizable particles can also be dispersed in the elastomer. 
     If an electro-rheological liquid is used, it is clear that it must be sealed in a suitable hollow chamber. 
     While electro-rheological elastomers can change shape and rigidity under the effects of an electric field, this effect is limited to a change in viscosity with electro-rheological liquids. 
     In both cases, there is a noticeable change in the feel for a user. 
     In the simplest case, driver assembly comprises a first and second electrode, between which an electric field can be applied. 
     This driver assembly preferably contains at least one flexible electrode, and the electro-rheological material is at least partially located between the electrodes. 
     Because at least one of the electrodes is therefore located at the end of the element formed by the electro-rheological material, and the shape of the element, in particular its length or width, can change, the electrode in question is preferably flexible. 
     According to a preferred embodiment of the invention, the driver assembly is designed to generate a vibration in the control element, in particular with different frequencies, different durations, and/or with an intermittent output, that the user can distinguish. 
     This makes it possible to indicate to a user through a vibration that an input, for example, has taken place correctly. 
     It is therefore possible, for example, to indicate to a user through a vibration that an input has taken place correctly, i.e. a telephone number has been fully input. Or it is possible to indicate to a user through different frequencies whether an input should take place to increase a specific value or decrease this value. Moreover, different frequencies can be used to give a user certain feedback, or request a specific input. Different durations and/or an intermittent output of a frequency can be used in a corresponding manner to communicate with a user. 
     According to another embodiment of the invention, the driver assembly is designed to allow at least part of the control element to protrude from or recess into a surface when activated. 
     The control element can then remain recessed in a surface when it is not needed, for example, and only protrude when input is needed. 
     The control element is preferably a knob or button. 
     According to another embodiment of the invention, the control element comprises numerous individual control elements, each of which has its own driver assembly. 
     An entire input panel can be obtained in this manner, e.g. for inputting a telephone number. 
     According to another embodiment of the invention, the first electrode is configured to actuate an electric switch mechanism, and can be moved manually, at least in part. 
     While the control element can otherwise be part of an electric switch mechanism, e.g. in the form of a rod or knob for actuating a switch, the control element can also be part of an electric switch mechanism that is actuated directly via the first electrode. The first electrode can preferably have a flexible segment, via which it is actuated. 
     In another embodiment of the invention, the first electrode is located on a first end of an electro-rheological elastomer, and comes in contact with an intermediate electrode when it is activated manually. 
     The electric switch mechanism can therefore be obtained between the first electrode and the intermediate electrode. The driver assembly is coupled to the first electrode and the second electrode, which is located on the other end of the elastomer. The change in feel is caused by the driver assembly. 
     This results in a particularly simple and compact design for the control element, resulting in both a switch mechanism, and a variable feel, with which it is possible to communicate with the user. 
     In another embodiment of the invention, there is a first electrode at one end and a second electrode at the other end of the elastomer. Both electrodes are coupled to the driver assembly, in order to obtain the variable feel. This switch mechanism has means for monitoring a change in the capacitance between the first and second electrodes, in order to register a movement of the first electrode. This enables a switching of the electric switch mechanism. 
     The control element can be combined in this manner with an electric switch mechanism, and galvanically separated from the driver assembly. 
     A control element according to the invention can preferably be produced through 3D printing. 
     Nearly any shape can be produced with 3D printing, such that the control element can be readily adapted to different applications and requirements. 
     As mentioned above, a control element according to the invention can preferably be used to communicate with a user, in that a noticeable change in the feel of the control element is produced. By way of example, a vibration can be used to give a user feedback regarding an activation of the control element, or request input from the user. 
     As mentioned above, a control element according to the invention can preferably be used in a vehicle, in particular a motor vehicle, rail vehicle, aircraft, or boat. 
     It is clear that the features of the invention specified above and explained below can be used not only in the respective combinations specified herein, but also in other combinations or in and of themselves, without abandoning the framework of the invention. 
    
    
     
       Further features and advantages of the invention can be derived from the following description of preferred exemplary embodiments in reference to the drawings. Therein: 
         FIG. 1  shows a schematic illustration of a control element according to the invention with an electro-rheological elastomer; 
         FIG. 2  shows a schematic illustration of a control element according to the invention with an electro-rheological liquid; 
         FIG. 3  shows a schematic illustration of a control element according to the invention composed of numerous individual electro-rheological elements; 
         FIG. 4  shows a partial view of a control element according to the invention, recessed in a surface when not in the activated state; 
         FIG. 5  shows a view of the control element shown in  FIG. 5 , in the activated state, wherein it protrudes partially from the surface; 
         FIG. 6  shows a schematic illustration of a control element composed of nine individual elements, wherein each individual element also has a switching surface; 
         FIG. 7  shows an enlargement of another embodiment of a control element according to the invention, which can be used as an electric switching element and also contains an electro-rheological elastomer for communicating with a user by changing the feel; and 
         FIG. 8  shows an enlargement of another embodiment of a control element according to the invention, which can be used as an electric switching element and also contains an electro-rheological elastomer for communicating with a user by changing the feel, wherein the electric switching element electronically evaluates the change in capacitance in order to trigger a switching process. 
     
    
    
     A control element according to the invention is indicated on the whole with the numeral  10  in the schematic illustration in  FIG. 1 . This is a control element  10  with an electro-rheological elastomer  12  in the form of a block, with an electric electrode on each end, a first electrode  16  and a second electrode  18 . A driver assembly  14  can provide electrical power to the two electrodes  16 ,  18 . A power source  20  is provided for this, shown schematically herein, as well as a switch. The power source  20  is normally an electronic power source that outputs a DC voltage or AC voltage, and the switch  22  is normally an electronic switch, operated via a suitable control. 
     Polarizable particles are dispersed in the electro-rheological elastomer  12 , that can be reversed when an electric field is applied. This results in a contraction, as indicated by the two arrows  23 ,  24  in  FIG. 1 . The elastomer itself can also be polarizable. 
     Because the electrodes  16 ,  18  are located on the ends of the elastomer  12 , they should be flexible, such that they can participate in a change in shape. The length or cross section, and/or the rigidity of the elastomer  12  can be altered by the driver assembly  14 , comprising the power source  20  and the switch  22 . A vibration can also be generated. 
     It should be clear that the electro-rheological elastomer  12  can be not only block-shaped, but practically any shape that can be produced with 3D printing. It can therefore be hollow, or a structured hollow shape, with various identical or different individual elements. 
       FIG. 2  shows a second embodiment of the control element according to the invention in a schematic illustration, indicated on the whole with the numeral  10   a . Corresponding reference symbols are used for corresponding parts herein, as is also the case in the following figures. 
     In the embodiment shown in  FIG. 2 , instead of an electro-rheological elastomer, an electro-rheological liquid  13  is used, which is sealed in a hollow chamber in an elastomer. 
     When an electric field is applied to the two electrodes  16 ,  18 , the electro-rheological (polarizable) molecules in the liquid become aligned between the electrodes  16 ,  18 , resulting in a greater rigidity in the system. 
     The control element  10  or  10   a  shown in  FIGS. 1 and 2  can be part of a switching element with which an electric switch is actuated. The control element  10  or  10   a  can therefore be part of a mechanical rod with which an electric switch is actuated. The driver assembly  14  is used to generate a variable feel by changing the shape and/or rigidity of the elastomer  12 , or liquid  13  that a user can notice. 
     As a result, feedback can be given to a user regarding whether the control element can been correctly actuated, to actuate a specific input. Furthermore, the elastomer  12  can be caused to vibrate, wherein different frequencies, durations, and/or an intermittent output can be used for exchanging information with the user. 
     The control element can also comprise numerous individual elements, as shown in  FIG. 3 . 
     The control element  10   b  shown in  FIG. 3  is composed, by way of example, of nine individual control elements  26 ,  27 ,  28 ,  29 ,  30 ,  31 ,  32 ,  33 ,  34 , arranged in the manner of a checkerboard. Each individual control element  26  to  34  contains its own driver assembly  14 , and can be controlled individually (connections not shown). 
     This allows for the realization of larger input fields, e.g. such as those for a telephone keypad. An individual switching can be implemented with each individual control element  26  to  34 , and communication with the user can take place through a change in shape or rigidity, thus generating a different feel that can be registered by a user. 
     Another embodiment of a control element according to the invention is shown in  FIGS. 4 and 5 , indicated on the whole by the numeral  10   d . This control element  10   d  is recessed in a surface  45  and can move therein. When activated, a part of the control element  10   d ′ protrudes from the surface  45 , as indicated by way of example in  FIG. 5 . 
       FIG. 6  shows another control element, indicated on the whole with the numeral  10   d , which is comprised of nine individual control elements  26  to  34  in a checkerboard arrangement. Each individual control element  26  to  34  also has a switching surface  47  that triggers an electric switching process when activated manually. As a result of the structure, a certain pressure characteristic is obtained when it is not activated, through which a switching process can be triggered when actuated manually (fail-safe operation). In the activated state, the switching characteristic can be altered, and communication can be established with the user, as described above. 
       FIG. 7  shows another control element by way of example, indicated on the whole with the numeral  10   e . This is a control element with which an electric switching element  50  is obtained with two electrodes  16 ,  49 , and which is also combined with an electro-rheological elastomer  12  in order to generate a variable feel. 
     There is a first electrode  16  at a first end of the electro-rheological elastomer  12 , which has a protruding switching surface  47 . Adjacent to this is an intermediate electrode  49 , which is electrically insulated from the first electrode  16  by an insulation layer  51 . If the protruding switching surface is depressed, contact is made with the underlying intermediate electrode  49 , such that an electric switching process takes place between the first electrode  16  and the intermediate electrode  49 . 
     The second electrode is at the other end of the electro-rheological elastomer  12 . An electric field can be applied between the first electrode  16  and second electrode  18  by a driver assembly in the manner described above, in order to change the shape or length or generate a variable feel. 
     Lastly,  FIG. 8  shows a variation on the embodiment shown in  FIG. 7 . The control element  10   f  also has a first electrode  16  and second electrode  18 , with an electro-rheological elastomer  12  sealed between them. The first electrode  16  also has a protruding switching surface  47  that can be actuated manually. 
     In differing from the embodiment shown in  FIG. 7 , there is no intermediate electrode. Instead, the capacitance between the two electrodes  16 ,  18  is monitored. When the switching surface  47  is depressed, the switch mechanism  50  registers a change in the capacitance, and executes a switching process between the two connections  52 ,  54 . A galvanic separation can be obtained for this between the two connections  52 ,  54  and the two electrodes  16 ,  18 . 
     REFERENCE SYMBOLS 
       10 ,  10   a ,  10   b ,  10   c ,  10   d ,  10   e ,  10   f  control element 
       12  elastomer 
       13  liquid 
       14  driver assembly 
       15  coil 
       16  first electrode 
       18  second electrode 
       20  power source 
       22  switch 
       23  arrow 
       24  arrow 
       26  individual control element 
       27  individual control element 
       28  individual control element 
       29  individual control element 
       30  individual control element 
       31  individual control element 
       32  individual control element 
       33  individual control element 
       34  individual control element 
       35  individual driver assembly 
       36  individual driver assembly 
       37  individual driver assembly 
       38  individual driver assembly 
       39  individual driver assembly 
       40  individual driver assembly 
       41  individual driver assembly 
       42  individual driver assembly 
       43  individual driver assembly 
       45  surface 
       47  switching surface 
       49  intermediate electrode 
       50  switching element 
       52  connection 
       54  connection