Actuating device for controlling a vehicle function

Abstract

The invention relates to an actuating device (10) for controlling a vehicle function, comprising a carrier device (16), a fluid cushion arrangement (11) with at least one fluid cushion (12) projecting from the carrier device (16), which includes at least one elastic shell (14) and a first volume (V1) containing an incompressible fluid (FL1) at least partially enclosed by the at least one elastic shell (14), and at least one hydropneumatic accumulator (15) fluidically connected to the first volume (V1), wherein the at least one elastic shell (14) is configured to receive an actuating force (FB) of a driver's foot multidirectionally such that a deformation of the at least one elastic shell (14) caused by the actuating force (FB) leads to a reduction of the enclosed first volume (V1) and thus to an increase in the internal pressure, wherein at least one sensor unit (20) is configuredto detect the deformation of the at least one elastic shell (14) caused by the actuating force (FB) and to transmit it to at least one evaluation and control unit (24) electrically coupled to the at least one sensor unit (20), which is designed to generate at least one control signal for controlling the vehicle function from the deformation of the elastic shell (14) caused by the actuating force (FB) detected by the at least one sensor unit (20).

Description

[0001] The invention relates to an actuating device for controlling a vehicle function.

[0002] From EP 1 459 928 B1, a device for accelerating and / or decelerating a motor vehicle is known, which has at least one actuating element. The actuating element is actuated by applying an actuating force. The actuating element operates with virtually no displacement, and the device can be operated in at least two driver-specific modes.

[0003] From WO 2020 / 142804 A1, a foot-operated vehicle control system with a pedal is known, which includes at least one load and / or pressure sensing device. The pedal is integrated into or mounted on the vehicle's floor structure and reacts to the force exerted by the user with minimal displacement of the sensor unit in order to generate control signals that can be used to control the vehicle's drive and / or braking function during operation.

[0004] From FR 3 017 339 A1, an actuating device is known which is capable of providing a command for a vehicle function. The actuating device comprises a component permanently installed in a footwell of the vehicle, which includes a front part elastically deformable by an actuating force of the driver's foot and at least one strain gauge which is attached behind and to the front part and is configured to convert a deformation of the front part caused by the actuating force of the driver's foot into a change in electrical resistance. In addition, at least one electronic circuit is connected to the strain gauge and configured to output a preconditioned signal at an output, which represents the elastic deformation derived from the change in electrical resistance and can be used to control the vehicle function. Disclosure of the invention

[0005] The actuating device for controlling a vehicle function with the features of independent claim 1 has the advantage that, in addition to an orthogonally acting actuating force, actuating forces acting from other directions can also be detected and evaluated. This means that even with non-orthogonal actuation of the actuating device, the actuation can be reliably detected and no tilting of the actuating device can occur. This advantageously results in a high level of operational safety of the actuating device.

[0006] Furthermore, embodiments of the invention provide a simple, cost-effective, robust, and diagnosable actuating device for controlling vehicle functions, in which the interpretation of the actuation request is reliable and robust. The required actuation force can be adapted to any requirements or customer wishes.

[0007] Embodiments of the present invention comprise an actuating device for controlling a vehicle function, with a carrier device, a fluid cushion arrangement with at least one fluid cushion projecting from the carrier device, which includes at least one elastic shell and a first volume containing an incompressible fluid, at least partially enclosed by the at least one elastic shell, and at least one hydropneumatic accumulator fluidically connected to the first volume. The at least one elastic shell is designed to absorb an actuating force from a driver's foot multidirectionally such that a deformation of the at least one elastic shell caused by the actuating force leads to a reduction of the enclosed first volume and thus to an increase in the internal pressure.In this case, at least one sensor unit is provided to detect the deformation of the at least one elastic shell caused by the actuating force and to forward it to at least one evaluation and control unit electrically coupled to the at least one sensor unit, which is designed to generate at least one control signal for controlling the vehicle function from the deformation of the elastic shell caused by the actuating force detected by the at least one sensor unit.

[0008] Embodiments of the actuating device according to the invention can be used as a "brake pedal" to perform a braking function or as an "accelerator pedal" to perform an acceleration function.

[0009] The mounting device can preferably be designed as a non-elastic support plate made of metal or plastic. The support plate can preferably be screwed to a floor panel or a firewall in the vehicle's footwell. This allows for particularly easy installation and removal of the operating device.

[0010] In this context, the term "evaluation and control unit" can be understood as an electrical device, such as a control unit, in particular a brake control unit or a drive control unit, which processes or evaluates acquired sensor signals. The evaluation and control unit can have at least one interface, which may be hardware-based and / or software-based. In a hardware-based design, the interfaces can, for example, be part of a so-called system ASIC, which incorporates various functions of the evaluation and control unit. However, it is also possible that the interfaces are separate integrated circuits or consist at least partially of discrete components. In a software-based design, the interfaces can be software modules that are present, for example, on a microcontroller alongside other software modules.A computer program product with program code stored on a machine-readable medium such as semiconductor memory, hard disk memory or optical memory, and used to perform the evaluation when the program is executed by the evaluation and control unit, is also advantageous.

[0011] In this context, a sensor unit is understood to be a component comprising at least one sensor element. This sensor element directly or indirectly detects a physical quantity or a change in a physical quantity and preferably converts it into an electrical sensor signal. In embodiments of the actuating device, the sensor signal represents pressure or a pressure change, or displacement or a displacement change, or force or a force change. Such sensor elements can provide information about changes in measured quantities very quickly. This allows resulting control signals for controlling the corresponding vehicle function to be generated and output preferably in less than 10 ms. Preferably, several sensor units can be used for redundant acquisition and evaluation of the measured quantity. In this context, different physical measurement methods are preferably employed for acquiring the measured quantity.

[0012] The measures and further developments listed in the dependent claims enable advantageous improvements to the actuating device for controlling a vehicle function specified in independent claim 1.

[0013] A particular advantage is that the at least one hydropneumatic accumulator can enclose two further volumes fluidically separated from each other by a movable partition. The incompressible fluid can be contained in the second volume, and a compressible fluid in the third. Preferably, a hydraulic fluid can be used as the incompressible fluid. Preferably, air can be used as the compressible fluid.

[0014] In a further advantageous embodiment of the actuating device, the movable separating element can, for example, be designed as a movably mounted piston which moves against the force of at least one spring element arranged in the third volume based on the increase in internal pressure caused by the actuating force. Here, the at least one sensor unit can be designed as a displacement sensor, which detects the spring deflection of the at least one spring element, representing the effective actuating force, as a measured variable. Additionally or alternatively, a sensor unit designed as a force sensor can detect the force acting on the at least one spring element based on the effective actuating force as a measured variable.Alternatively, the movable separating element can be designed as an elastically deformable membrane which moves against the compressible fluid based on the increase in internal pressure caused by the actuating force, thus compressing it. In this case, the at least one sensor unit can be designed as a pressure sensor which detects the internal pressure present in the first, second, or third volume as the measured quantity representing the effective actuating force.

[0015] In a further advantageous embodiment of the actuating device, the base of the at least one spring element can be adjustable. The actuation characteristic of the device can be defined statically via properties of the at least one spring element or dynamically via adjustment of the base of the at least one spring element. The actuation characteristic can be adjusted via the stiffness of the at least one spring element. By selecting the appropriate spring, the actuation feel can be made firmer or softer, and the corresponding actuation travel can be shorter or longer. Another possible embodiment is a progressive characteristic. For example, the actuation characteristic can be set soft at the beginning of the actuation for better modulation. As the actuation force increases, the actuation characteristic can be made firmer to prevent the actuation travel from becoming too long.In everyday comfort ranges, with a delay of up to approximately -3 m / s. 2 The actuation characteristic would thus be set to a soft setting. This applies to critical braking situations with a deceleration of approximately -6 m / s² or more. 2 The actuation characteristic would, however, be set to a firm setting. The transition can be smooth via a progressive spring element or stepped, preferably via a series connection of several spring elements with different stiffness. Furthermore, the stiffness can be adapted by adjusting the base point of at least one spring element. For example, the base point of the at least one spring element can be adjusted using a screw. This can be done at the factory during the production process to meet customer specifications. With adaptive base point adjustment using an actuator, customer-specific adjustments for the driver are even possible while the vehicle is stationary.

[0016] In a further advantageous embodiment of the actuating device, the third volume can be connected to at least one outlet channel, which includes at least one restrictor and is designed to generate a volume flow rate in the at least one outlet channel that can be predetermined by the at least one restrictor. This flow rate counteracts the increase in internal pressure in the enclosed third volume caused by the actuating force during actuation. This allows haptic feedback to be generated at the driver's foot. The at least one outlet channel and the corresponding volume flow rate allow specific requirements for a particular "pedal feel" to be implemented with minimal or no hardware modifications. Actuating devices with the fluid cushion arrangement and pressure adaptation could therefore be used generically across various vehicle models. For a pleasant orTo achieve the desired "pedal feel" and to specify a "minimum pedal travel," a throttled fluid flow can escape from the enclosed volume via the at least one outlet channel when the pedal is actuated. Advantageously, the at least one outlet channel can be connected to the environment or atmosphere via a replaceable fluid filter. The replaceable fluid filter advantageously prevents dirt from entering the enclosed volume via the at least one outlet channel. The at least one throttle can be designed as a replaceable static throttle element, which generates a constant throttling effect. Such a static throttle element reduces the effective cross-section of the corresponding outlet channel. The replaceable static throttle element preferably has a thread with which it can be screwed into the at least one outlet channel.By selecting and inserting the interchangeable throttle element, various constant throttling effects can be specified, generating corresponding desired "pedal feels." Alternatively, the exhaust port itself can act as a static throttle element, the constant throttling effect of which can be set and specified via its selected effective diameter. Alternatively, at least one throttle can be implemented as an adjustable valve capable of generating a static or dynamic throttling effect. The adjustable valve allows for both static and dynamic adjustment of the internal pressure profile within the enclosed third volume. The evaluation and control unit can be further configured to specify the desired static or dynamic throttling effect by actuating the adjustable valve. In addition to the potential for dynamic adjustment, the advantage of this design is that it allows for adjustment of the operating characteristics.The pedal characteristics can be adjusted solely through software modification. This allows the same hardware to meet the specific requirements of different vehicle models. Furthermore, adjustments can be made while the vehicle is in operation. In principle, this also allows for adaptation to potential aging effects over the vehicle's lifespan. Additionally, the adjustable valve allows for setting the current internal pressure in the enclosed third volume when the pedal is not engaged. This internal pressure can be adjusted based on current environmental conditions. This allows the internal pressure in the enclosed volume to be preferably adapted to relevant air pressure fluctuations, ensuring a consistent pedal feel. In particular, altitude differences of several hundred meters can cause significant changes in air pressure. Therefore, altitude adaptation is beneficial.To compensate for height differences, the adjustable valve can be briefly fully opened to equalize the pressure between the ambient environment and the enclosed third volume. Furthermore, the throttling effect of the adjustable valve can be adjusted depending on the current ambient conditions and / or the current internal pressure within the enclosed volume. This prevents undesirable stiffness during operation of the actuator. Additionally, depending on the internal pressure profile, a dynamic fluid flow can be released from the enclosed third volume during actuation, thereby reducing the internal pressure and providing a longer operating travel or "pedal travel" and / or a more comfortable "pedal feel."

[0017] In a further advantageous embodiment of the actuating device, an actuating element can be arranged above the at least one fluid cushion and connected to a surface of the at least one fluid cushion facing away from the support device. This actuating element is designed to receive the actuating force of the driver's foot multidirectionally and transmit it to the at least one elastic sleeve of the at least one fluid cushion. The actuating element, which is arranged on the fluid cushion assembly and can preferably be designed as a classic actuating plate, can achieve the appearance of a classic pedal, preferably a brake pedal. Furthermore, embodiments of the actuating device allow for easy installation of the actuating element and multidirectional operation with a largely identical pedal feel for the driver.Furthermore, embodiments of the actuating device can be robustly designed to withstand tensile loads, which can prevent excessive tilting, particularly when the actuating force is applied only to one corner of the actuating element designed as an actuating plate. Additionally, the actuating plate design can offer a cost-effective mounting option.

[0018] In a further advantageous embodiment of the actuating device, the at least one elastic shell of the at least one fluid cushion can have a partial reinforcement on a surface facing the actuating element, to which the actuating element is detachably or permanently connected. The detachable connection can preferably be realized via clamping and / or snap-fit ​​connections between the actuating element and the partial reinforcement of the elastic shell of the at least one fluid cushion. For this purpose, corresponding snap hooks can be formed on a surface facing the fluid cushion, and a corresponding undercut can be formed on the partial reinforcement of the elastic shell of the at least one fluid cushion, behind which the snap hooks engage to form the corresponding clamping and / or snap connection. The detachable connection allows the actuating element to be replaced easily and quickly for repair or maintenance.Simultaneously, the releasable clamping and / or snap-fit ​​connections ensure that the actuating element cannot be unintentionally detached during use or cleaning of the vehicle. Alternatively, non-releasable connections, such as adhesive bonds, can be implemented between the actuating element and the area-specific reinforcement of the elastic casing of the at least one fluid cushion to connect the actuating element to the at least one fluid cushion of the fluid cushion assembly. The actuating element can preferably be designed as an actuating plate with a non-slip surface. Materials for the actuating plate can include, for example, metals, rigid plastics, hardwoods, or a combination of different materials. To achieve the non-slip surface, rubber applications, for example, can be arranged on the surface of the actuating plate.

[0019] In a further advantageous embodiment of the actuating device, the volume at least partially enclosed by the at least one elastic shell of the individual fluid cushions can form a spherical segment, preferably a hemisphere, in the unactuated state. Alternatively, the volume at least partially enclosed by the at least one elastic shell can form a layer of spheres in the unactuated state, the top and bottom surfaces of which are non-deformable. In particular, the design as a spherical segment or hemisphere can advantageously support the effect that any deformation of the at least one elastic shell due to an actuating force applied to the actuating element by the driver leads to a reduction of the enclosed volume and thus to an increase in the internal pressure within the enclosed volume.Of course, other suitable geometric shapes can also be implemented to achieve the desired effect. Advantageously, the at least one elastic shell can be designed as a single-layer or multi-layer elastic membrane. The material, number of layers, and thickness can be selected to achieve an acceptable force-displacement curve, taking into account wear resistance. The material can advantageously be chosen to remain elastic and non-porous throughout the service life of the actuating device and to be sufficiently robust against expected chemical and mechanical stresses. Furthermore, one of the layers can contain flexible reinforcement to increase the service life of the elastic membrane.

[0020] In a further advantageous embodiment of the actuating device, the fluid cushion arrangement can comprise several fluid cushions, which are arranged below the actuating element and connected to it. At least two of the multiple fluid cushions can be fluidically connected to each other via a common hydropneumatic reservoir. Here, the individual first volumes containing the incompressible fluid and a second volume containing the incompressible fluid of the common hydropneumatic reservoir, which are at least partially enclosed by the at least one shell of the at least two fluid cushions, form a common enclosed volume that is fluidically separated from the third volume containing the compressible fluid of the common hydropneumatic reservoir.Without a shared hydropneumatic reservoir, the measured value representing the actuating force of each individual fluid cushion can be individually acquired and evaluated by a sensor unit. To detect leaks, the measured values ​​of the individual fluid cushions can be compared. When multiple fluid cushions are connected to a shared hydropneumatic reservoir, the measured value representing the actuating force within the reservoir can be acquired and evaluated by a single sensor unit. This reduces the number of sensor units required. For availability in case of a failure, preferably at least two hydropneumatic reservoirs, each with its own sensor unit, can be used, each fluidically connected to multiple fluid cushions.In this system, at least one sensor unit can preferably be arranged and configured within the common hydropneumatic reservoir to detect the applied actuating force. To detect leaks, the measured values ​​representing the applied actuating force from at least two hydropneumatic reservoirs can be compared. Machine learning can be used to train the system for this comparison and to define normal and fault conditions, or to differentiate between the two states.

[0021] In a further advantageous embodiment of the actuating device, at least one additional sensor unit can be electrically coupled to the at least one evaluation and control unit and configured to redundantly detect the actuating force. For this purpose, the at least one additional control unit can, for example, be arranged outside the at least one fluid cushion on the support device. Here, a sensor signal from the at least one additional sensor unit can represent pressure or a pressure change, or displacement or a displacement change, or force or a force change. Preferably, the at least one additional sensor unit can be configured as a displacement sensor or as a force sensor.By using at least one second sensor unit, which provides information about the acting actuating force, at least one control signal can preferably be generated and output to control the vehicle function in the event of a fault, for example, in the case of at least one leaking fluid cushion in the fluid cushion assembly. At the same time, the use of at least one additional sensor unit enables immediate diagnosis and feedback of the fault.

[0022] Exemplary embodiments of the invention are shown in the drawings and are explained in more detail in the following description. In the drawings, identical reference numerals denote components or elements that perform the same or analogous functions. Brief description of the drawings Fig. Figure 1 shows a schematic partial representation of a footwell of a vehicle with a top view of a first embodiment of an actuating device according to the invention for controlling a vehicle function. Fig. Figure 2 shows a schematic sectional view of the actuating device according to the invention. Fig. 1. Fig. Figure 3 shows a schematic sectional view of a second embodiment of the actuating device according to the invention. Fig. Figure 4 shows a schematic sectional view of a third embodiment of the actuating device according to the invention. Fig. Figure 5 shows a schematic partial representation of a footwell of a vehicle with a top view of a fourth embodiment of an actuating device according to the invention for controlling a vehicle function. Fig. Figure 6 shows a schematic sectional view of the actuating device according to the invention. Fig. 5. Embodiments of the invention

[0023] As from Fig. As can be seen from Figures 1 to 6, the illustrated embodiments of an actuating device 10 according to the invention for controlling a vehicle function each comprise a carrier device 16, a fluid cushion arrangement 11 with at least one fluid cushion 12 projecting from the carrier device 16, which comprises at least one elastic shell 14 and a first volume V1 containing an incompressible fluid FL1, at least partially enclosed by the at least one elastic shell 14, and at least one hydropneumatic accumulator 15 fluidically connected to the first volume V1. The at least one elastic shell 14 is designed to absorb an actuating force FB of a driver's foot multidirectionally such that a deformation of the at least one elastic shell 14 caused by the actuating force FB leads to a reduction of the enclosed first volume V1 and thus to an increase in the internal pressure.In this case, at least one sensor unit 20 is provided to detect the deformation of the at least one elastic shell 14 caused by the actuating force FB and to forward it to at least one evaluation and control unit 24 electrically coupled to the at least one sensor unit 20, which is designed to generate at least one control signal for controlling the vehicle function from the deformation of the elastic shell 14 caused by the actuating force FB detected by the at least one sensor unit 20.

[0024] In the illustrated embodiments, the actuating device 10 is used as a "brake pedal" to perform a braking function. Of course, another actuating device 10 according to the invention could also be used as an "accelerator pedal" to perform an acceleration function.

[0025] In the illustrated embodiments, the support device 16 is designed as an inelastic support plate 16A made of metal or plastic and is screwed to a floor plate or a firewall 3 in the footwell 1 of the vehicle by means of screws (not shown). Furthermore, the components described in Fig. 1, Fig. 2, Fig. 3, Fig. 5 and Fig. In the illustrated embodiments of the actuating device 10A, 10B, 10D, each contains only one hydropneumatic accumulator 15, which encloses two further volumes V2, V3 that are fluidically separated from each other by a movable separating element 15.1. The incompressible fluid FL1 is contained in the second volume V2, and a compressible fluid FL2 is contained in the third volume V3. In the illustrated embodiments, a hydraulic fluid is used as the incompressible fluid FL1. Air is used as the compressible fluid FL2.

[0026] As from Fig. As can be seen further in Figures 2 to 4, in the illustrated embodiments of the actuating device 10A, 10B, 10C, the elastic shells 14A of the individual fluid cushions 12 and the enclosed first volume V1 each form a spherical layer in the unactuated state, the top and bottom surfaces of which are non-deformable. This allows actuating forces FB, which act on the respective fluid cushion 12 from different directions via an actuating element 17 designed as an actuating plate 17A, to be reliably detected and evaluated via the resulting increase in the internal pressure in the enclosed first volume V1. This enables multidirectional operation of the actuating device 10A, 10B, 10C with a largely identical "pedal feel" for the driver. To create a non-slip surface, several strip-shaped rubber applications 17.1 are arranged on the surface of the actuating plate 17A.Naturally, the rubber applications 17.1 can also have a different shape, such as a circle, or a different orientation. In the illustrated embodiments, the first volume V1 is enclosed by the corresponding elastic shell 14A and a surface of the support device 16 facing the elastic shell 14A.

[0027] As from Fig. 2 and Fig. As can be seen further in Figure 3, the fluid cushion arrangement 11 in the illustrated embodiments of the actuating device 10A, 10B each comprises a fluid cushion 12, which has only one elastic shell 14A enclosing the first volume V1 filled with the incompressible fluid FL1. The elastic shells 14A of the individual fluid cushions 12 are preferably each designed as a multi-layered elastic membrane. The material, number of layers, and thickness can be selected for wear resistance reasons to achieve an acceptable force-displacement curve.

[0028] At the in Fig. In the third embodiment of the actuating device 10C shown in Figure 4, the fluid cushion arrangement 11 comprises four fluid cushions 12, two of which are visible. Each fluid cushion 12 comprises only one elastic shell 14A enclosing the first volume V1 filled with the incompressible fluid FL1. The elastic shells 14A of the individual fluid cushions 12 are preferably designed as a multilayer elastic membrane. The material, number of layers, and thickness can be selected to achieve an acceptable force-displacement curve for reasons of wear resistance. In embodiments of the actuating device 10 not shown, the fluid cushion arrangement 11 can also comprise more than four fluid cushions 12, for example, six, eight, or nine fluid cushions 12.

[0029] As from Fig. As can be seen further in Figure 4, in the third embodiment of the actuating device 10C, at least two of the several fluid cushions 12 are fluidically connected to each other via a common hydropneumatic reservoir 15. Here, the individual first volume V1 containing the incompressible fluid FL1 and the second volume V2 containing the incompressible fluid FL1 of the common hydropneumatic reservoir 15, which are at least partially enclosed by the elastic shell 14 of the at least two fluid cushions 12, form a common enclosed volume that is fluidically separated from the third volume V3 containing the compressible fluid FL2 of the common hydropneumatic reservoir 15. In the Fig. In the illustrated embodiment 4, two common hydropneumatic accumulators 15 are integrated into the support device 16, one of which is visible. Here, a first hydropneumatic accumulator 15, shown, is fluidically connected to elastic shells 14 of two of the four fluid cushions 12. This means that the common volume comprises the at least partially enclosed individual first volumes V1 of the elastic shells 14 of the two fluid cushions 12 and the second volume V2 of the first hydropneumatic accumulator 15. A second hydropneumatic accumulator 15, not shown in detail, is fluidically connected to elastic shells 14 of the other two of the four fluid cushions 12. This means that the common volume comprises the at least partially enclosed individual first volumes V1 of the elastic shells 14 of the two fluid cushions 12 and the second volume V2 of the second hydropneumatic accumulator 15.

[0030] As from Fig. As can be seen further in Figure 4, a sensor unit 20, designed as a pressure sensor 20A, is arranged and configured in the first hydropneumatic reservoir 15 shown to detect the internal pressure in the enclosed common volume. Naturally, for fluid cushion arrangements 11 with more than four fluid cushions 12, more than two hydropneumatic reservoirs 15 can also be used, each of which is fluidically connected to the elastic shells 14 of at least two fluid cushions 12. For example, in an embodiment of the fluid cushion arrangement 11 with six fluid cushions 12, three hydropneumatic reservoirs 15 can be used, each of which is fluidically connected to the elastic shells 14 of two of the six fluid cushions 12. In this case, the multiple common enclosed volumes can be filled with different media.For example, a first enclosed volume can be filled with a compressible fluid FL2, such as air, and a second enclosed volume can be filled with an incompressible fluid FL1, such as a liquid.

[0031] At a Fig. 5 and Fig. In the fourth embodiment of the actuating device 10D shown in Figure 6, the fluid cushion arrangement 11 comprises only one fluid cushion 12, the elastic shell of which includes an outer membrane 14.1 and an inner membrane 14.2, between which a space filled with a compressible fluid FL2, preferably air, is formed. Here, the elastic shell 14B of the fluid cushion 12, or the outer membrane 14.1 and the inner membrane 14.1 and the enclosed first volume V1, each form a hemisphere as a special spherical segment in the unactuated state. In the illustrated embodiment, the first volume V1 is enclosed by the elastic shell 14B and a surface of the support device 16 facing the elastic shell 14B. In this embodiment, the elastic shell 14B directly receives the actuating force FB of the driver's foot multidirectionally without an additional actuating element 17. The inner membrane 14.1 and the outer membrane 14.1...2 are preferably multilayered. The material, number of layers, and thickness can be selected to achieve an acceptable force-displacement curve for wear resistance. In an alternative embodiment of the actuating device 10 (not shown), individual layers of the multilayered outer membrane 14.1 have different colors, allowing different degrees of wear to be distinguished. For example, an outer first layer can have a neutral color, indicating to the driver that the wear of the outer membrane 14.1 is within a normal range. A middle second layer can, for example, have a warning color, such as yellow, to indicate to the driver that a first wear stage has been reached.An inner third layer may, for example, have a second warning color, such as red, to indicate to the driver that a critical level of wear of the outer membrane 14.1 has been reached and that the elastic sheath 14B should be replaced.

[0032] As from Fig. As can be seen further in Figures 2 to 4, the elastic sheaths 14A of the individual fluid cushions 12 each have a partial reinforcement 13 on a surface facing the actuating element 17, to which the actuating element 17 is connected. In the Fig. In embodiments 2 to 4 shown, non-removable adhesive connections are formed between the actuating element 17 and the area-specific reinforcements 13 of the corresponding elastic shells 14 of the individual fluid cushions 12 in order to permanently connect the actuating element 17 with the individual air cushions 12 of the fluid cushion arrangement 11.

[0033] In alternative embodiments not shown, a detachable connection is achieved by means of several screw connections between the actuating element 17, designed as an actuating plate 17A, and the area-specific reinforcements 13 of the elastic shells 14 of the individual fluid cushions 12. In another embodiment not shown, the detachable connection is realized via several clamping and / or snap-fit ​​connections between the actuating element 17, designed as an actuating plate 17A, and the area-specific reinforcements 13 of the corresponding elastic shells 14 of the individual fluid cushions 12. Furthermore, other suitable connection methods can also be used to realize the detachable connection or to realize a non-detachable connection.

[0034] As from Fig. As can be seen further in Figures 2 to 6, the elastic shell 14 of the individual fluid cushions 12 in the illustrated embodiments of the actuating device 10 is designed as an open shell 14. Here, an edge region 19 of the open shells 14 of the individual fluid cushions 12 facing the support device 16 is fluid-tightly connected to the support device 16. The edge region 19 of the open shells 14 of the individual fluid cushions 12 is designed such that it does not undergo any deformation due to the acting actuating force FB. For this purpose, the edge region 19 of the open shells 14B of the individual fluid cushions 12 in the illustrated embodiments of the actuating device 10 is connected to the support device 16 via a seal 18. In the illustrated embodiments, the seal 18 is designed as an annular seal 18A.

[0035] In an embodiment of the actuating device 10 not shown, an external thread is applied to the edge region 19 of the open shells 14 of the individual fluid cushions 12 in addition to the seal 18, so that the edge region 19 can be screwed to the support device 16.

[0036] In alternative embodiments of the actuating device 10 not shown, the elastic shell 14 of each individual fluid cushion 12 is designed as a closed shell 14. In this case, one side of the closed shell 14 of each fluid cushion 12 facing the support device 16 rests flat on the support device 16 and is connected to it. Preferably, the closed shells 14A of the individual fluid cushions 12 are bonded to the support device 16 via a contact surface and designed such that they do not undergo any deformation due to the acting actuating force FB. Furthermore, the closed shell 14 and the enclosed first volume V1 are fluidically connected to the second volume V2 of the corresponding hydropneumatic reservoir 15 via at least one compensating connection.

[0037] As from Fig. 2 and Fig. As can be seen further in Figure 4, in the illustrated embodiments of the actuating device 10A, 10C, the hydropneumatic accumulator 15 is designed as a pressure chamber 15A integrated into the support device 16. The second volume V2, containing the incompressible fluid FL1, is fluidically connected to the first volume V1, containing the incompressible fluid FL1 and at least partially enclosed by the elastic shell 14, via at least one connecting channel (not specified in detail). The second volume V1 is fluidically separated from the third volume V3, containing the compressible fluid FL2, by a separating element 15.1A designed as a movable piston 15.1A. The piston 15.1A is moved against the force of at least one spring element 15.2 arranged in the third volume V3 based on the increase in internal pressure caused by the actuating force FB.

[0038] As from Fig. 2 and Fig. As can be seen further in Figure 4, in the illustrated embodiments only one spring element 15.2 is arranged in the third volume V3. At the base of the spring element 15.2, a sensor unit 20, designed as a displacement sensor 20B, is installed to detect the spring displacement of the spring element 15.2, representing the effective actuating force FB, as a measured quantity. In an alternative embodiment of the actuating device 10 (not shown), the sensor unit 20 is designed as a force sensor, which detects the force acting on the at least one spring element 15.2, based on the effective actuating force FB, as a measured quantity.

[0039] As from Fig. 2 and Fig. As can be seen further in Figure 4, a sensor unit 20, designed as a pressure sensor 20A, is arranged in the second volume V2 of the pressure chamber 15A. The sensor unit 20, designed as a pressure sensor 20A, detects the existing internal pressure as the measured quantity representing the effective actuating force FB. This results in the spring deflection of the spring element 15.2, representing the effective actuating force FB, or the force acting on the at least one spring element 15.2 based on the effective actuating force FB, and the internal pressure in the second volume V2, representing the effective actuating force FB, being output to the evaluation and control unit 24 as two redundant measured quantities representing the current effective actuating force FB.

[0040] In the illustrated embodiments of the hydropneumatic accumulator 15, designed as a pressure chamber 15A, the actuation characteristic of the actuating device 10 can be statically defined by the properties of the spring element 15.2 used. Furthermore, several spring elements 15.2 with different degrees of stiffness can be used to define a stepwise change in the actuation characteristic of the actuating device 10. In an alternative embodiment of the actuating device 10 (not shown), the base of the spring element 15.2 is adjustable. In such an embodiment, a dynamic change in the actuation characteristic can be achieved by adjusting the base of the at least one spring element 15.2.

[0041] As from Fig. 3 and Fig. As can be seen further in Figure 6, in the illustrated embodiments of the actuating device 10B, 10D, the hydropneumatic accumulator 15 is designed as a spherical accumulator 15B arranged outside the support device 16. Here, the second volume V2 containing the incompressible fluid FL1 is fluidically connected to the first volume V1 containing the incompressible fluid FL1, which is at least partially enclosed by the elastic shell 14, via at least one connecting channel (not specified in detail). The second volume V1 is fluidically separated from the third volume V3 containing the compressible fluid FL2 by a separating element 15.1B designed as an elastically deformable membrane 15.1B. Based on the increase in internal pressure caused by the actuating force FB, the elastically deformable membrane 15.1B moves against the compressible fluid FL2 in the third volume V3, thus compressing the compressible fluid FL2.

[0042] As from Fig. 3 and Fig. As can be seen further in Figure 6, a first sensor unit 20, designed as a pressure sensor 20A, is arranged in the second volume V2, and a second sensor unit 10, also designed as a pressure sensor 20A, is arranged in the third volume V3 of the ball storage unit 15B. The two sensor units 20, designed as pressure sensors 20A, each detect an existing internal pressure as the measured quantity, which represents the effective actuating force FB. This results in two redundant measured quantities, representing the current effective actuating force FB, being output to the evaluation and control unit 24 for evaluation.

[0043] As from Fig. As can be seen further in Figure 6, in the fourth embodiment of the actuating device 10D, a third sensor unit 20, designed as a pressure sensor 20A, is arranged in the first volume V1, which is enclosed by the elastic shell 14B and the surface of the support device 16 facing the elastic shell 14B. Therefore, in the fourth embodiment of the actuating device 10D, three sensor units 20, each designed as a pressure sensor 20A, detect an existing internal pressure as the measured quantity representing the effective actuating force FB. This results in three redundant measured quantities, representing the current effective actuating force FB, being output to the evaluation and control unit 24 for evaluation.

[0044] In an alternative embodiment not shown, the third sensor unit 20, arranged in the first volume V1 of the fluid cushion 12, which is at least partially enclosed by the elastic shell 14B, uses a different physical measurement method to determine the deformation of the elastic shell 14B caused by the actuating force FB. For example, third sensor units 20, designed as force sensors in the form of at least one strain gauge, can be arranged on the elastic shell 14B to detect the deformation caused by the actuating force FB. Of course, other suitable physical measurement methods can also be used for redundant detection of the deformation caused by the actuating force FB. For example, the third sensor units 20 can be designed as optical sensors or radar sensors, etc.

[0045] As from Fig. 3 and Fig. As can be seen further in Figure 6, the third volume V3 containing the compressible fluid FL2 in the illustrated embodiments of the actuating device 10B, 10D is each connected to an outlet channel 26, which includes at least one throttle 28. The outlet channel 26 is designed to generate a volume flow rate in the outlet channel 26, which can be predetermined by the at least one throttle 28. When actuated, this flow rate counteracts the increase in internal pressure in the enclosed third volume V3 caused by the actuating force FB. An actuating characteristic of the actuating device 10B, 10D can be predetermined via the at least one throttle 28, either statically via a static throttle element or statically and dynamically via an adjustable throttle element 28A.

[0046] As from Fig. 3 and Fig. As can be seen further in Figure 6, the throttling device 28 in the illustrated embodiments of the actuating device 10B, 10D is each designed as an adjustable throttling element 28A, which generates a static or dynamic throttling effect. The evaluation and control unit 24 is further designed to specify the static or dynamic throttling effect by controlling an actuating element 29 of the adjustable throttling element 28A, which is designed as a servo motor. The adjustable throttling element 28A allows the current internal pressure in the enclosed third volume V3 to be set in the unactuated state. In the illustrated embodiment, the current internal pressure in the enclosed third volume is adjustable depending on the current ambient conditions in order to adapt the internal pressure in the enclosed third volume V3 to altitude.In addition, the throttling effect of the adjustable throttling element 28A in the illustrated embodiments of the actuating device 10B, 10D is adjustable depending on the current ambient conditions and / or the current internal pressure in the enclosed first volume V1 and the enclosed second volume V2.

[0047] In an alternative embodiment of the actuating device 10 (not shown), the at least one throttle 28 is designed as an interchangeable static throttle element that generates a constant throttling effect. Here, the static throttle element preferably comprises an external thread through which it is screwed to a corresponding internal thread of the corresponding outlet channel 26. Alternatively, the outlet channel 26 itself can act as a static throttle element, the constant throttling effect of which can be adjusted and predetermined via its selected effective diameter. Furthermore, the outlet channel 26 is connected to the environment or atmosphere via an interchangeable fluid filter.

[0048] As from Fig.As can be seen further in Figure 4, in the illustrated third embodiment of the actuating device 10C, a further sensor unit 22 is arranged between the individual fluid cushions 12 on the carrier device 16 as a fallback solution. This sensor unit is electrically coupled to the evaluation and control unit 24 and is designed to redundantly detect the actuating force FB. For this purpose, the further sensor unit 22 is designed as a force sensor 22A. By using further sensor units 22, in the event of a fault, for example, if at least one fluid cushion 12 of the fluid cushion arrangement 11 leaks, at least one control signal can be generated and output to control the vehicle function. At the same time, the use of the further sensor unit 22 enables immediate diagnosis and feedback of the fault. In the illustrated embodiment, the sensor unit 22 designed as a force sensor 22A serves purely as a fallback solution in the event of a fault.

[0049] In an embodiment not shown, at least one further sensor unit 22 arranged between the individual fluid cushions 12 on the support device 16 is designed as a displacement sensor, which detects the distance of an underside of the actuating plate 17A to the respective sensor unit 22. This allows redundant information about the actuating force FB to be provided in addition to the information from the sensor units 20 designed as pressure sensors 20A and to be evaluated by the evaluation and control unit 24. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] EP 1 459 928 B1

[0002] WO 2020 / 142804 A1

[0003] FR 3 017 339 A1

[0004]

Claims

[1] Actuating device (10) for controlling a vehicle function, comprising a carrier device (16), a fluid cushion arrangement (11) with at least one fluid cushion (12) projecting from the carrier device (16), which includes at least one elastic shell (14) and a first volume (V1) containing an incompressible fluid (FL1) at least partially enclosed by the at least one elastic shell (14), and at least one hydropneumatic accumulator (15) fluidically connected to the first volume (V1), wherein the at least one elastic shell (14) is configured to receive an actuating force (FB) of a driver's foot multidirectionally such that a deformation of the at least one elastic shell (14) caused by the actuating force (FB) leads to a reduction of the enclosed first volume (V1) and thus to an increase in the internal pressure, wherein at least one sensor unit (20) is configuredto detect the deformation of the at least one elastic shell (14) caused by the actuating force (FB) and to transmit it to at least one evaluation and control unit (24) electrically coupled to the at least one sensor unit (20), which is designed to generate at least one control signal for controlling the vehicle function from the deformation of the elastic shell (14) caused by the actuating force (FB) detected by the at least one sensor unit (20). [2] Actuating device (10) according to claim 1, characterized by , that the at least one hydropneumatic storage unit (15) encloses two further volumes (V2, V3) which are fluidically separated from each other by a movable separating element (15.1), wherein the incompressible fluid (FL1) is contained in a second volume (V2) and a compressible fluid (FL2) is contained in a third volume (V3). [3] Actuating device (10) according to claim 2, characterized by, that the movable separating element (15.1) is designed as a movable piston (15.1A) which moves against the force of at least one spring element (15.2) arranged in the third volume (V3) based on the increase in internal pressure caused by the actuating force (FB), or as an elastically deformable membrane (15.1B) which moves against the compressible fluid (FL2) and compresses it based on the increase in internal pressure caused by the actuating force (FB). [4] Actuating device (10) according to claim 3, characterized by , that the at least one sensor unit (20) is designed as a displacement sensor (20B) which detects as a measured variable a spring travel of the at least one spring element (15.2) representing the effective actuating force (FB), and / or as a force sensor which detects as a measured variable a force effect on the at least one spring element (15.2) based on the effective actuating force (FB). [5] Actuating device (10) according to claim 3 or 4, characterized by , that a foot point of the at least one spring element (15.2) is designed to be adjustable. [6] Actuating device (10) according to one of claims 3 to 5, characterized by , that an actuation characteristic of the actuating device (10) can be specified statically via properties of the at least one spring element (15.2) or dynamically via the adjustment of the base point of the at least one spring element (15.2). [7] Actuating device (10) according to any one of claims 1 to 6, characterized by , that the at least one sensor unit (20) is designed as a pressure sensor (20A) which detects an internal pressure present in the first volume (V1) or in the second volume (V2) or in the third volume (V3) as a measured quantity representing the effective actuating force. [8] Actuating device (10) according to one of claims 2 to 7, characterized by, that the third volume (V3) is connected to at least one outlet channel (26) which includes at least one throttling (28) and is designed to generate a volume flow rate in the at least one outlet channel (26) that can be specified by the at least one throttling (28) and which, when actuated, acts against the increase in internal pressure in the enclosed third volume (V3) caused by the actuating force (FB). [9] Actuating device (10) according to claim 8, characterized by , that an actuation characteristic of the actuating device (10) can be specified statically via a static throttling element or statically and dynamically via an adjustable throttling element (28A) via the at least one throttling (28). [10] Actuating device (10) according to any one of claims 1 to 9, characterized by, that an actuating element (17) is arranged above the at least one fluid cushion (12) and is connected to a surface of the at least one fluid cushion (12) facing away from the support device (16) and is designed to receive the actuating force (FB) of the driver's foot multidirectionally and to transmit it to the at least one elastic shell (14) of the at least one fluid cushion (12). [11] Actuating device (10) according to claim 10, characterized by , that the at least one elastic shell (14) of the at least one fluid cushion (12) has a partial reinforcement (13) on a surface facing the actuating element (17), with which the actuating element (17) is detachably or permanently connected. [12] Actuating device (10) according to any one of claims 1 to 11, characterized by, that the first volume (V1) which is at least partially enclosed by the at least one elastic shell (14) of the individual fluid cushions (12) forms a spherical segment or a spherical layer in the unactuated state. [13] Actuating device (10) according to one of claims 10 to 12, characterized by , that the fluid cushion arrangement (11) comprises several fluid cushions (12) which are arranged below the actuating element (17) and connected to it. [14] Actuating device (10) according to claim 13, characterized by, that at least two of the several fluid cushions (12) are fluidically connected to each other via a common hydropneumatic reservoir (15), wherein the individual first volume (V1) containing the incompressible fluid (FL1) and a second volume (V2) containing the incompressible fluid (FL2) of the common hydropneumatic reservoir (15), which are at least partially enclosed by the at least one shell (14) of the at least two fluid cushions (12), form a common enclosed volume which is fluidically separated from the third volume (V3) containing the compressible fluid (FL2) of the common hydropneumatic reservoir (15). [15] Actuating device (10) according to any one of claims 1 to 14, characterized by , that at least one further sensor unit (22) is electrically coupled with the at least one evaluation and control unit (24) and is designed to detect the actuating force (FB) redundantly.

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