Vehicle with a cover element that is adjustable relative to a wheel rim

Abstract

The invention relates to a vehicle with a cover element (2) movable relative to a wheel rim and at least one actuator, wherein the actuator is configured to receive a control signal from a control unit and to move the cover element (2) between a closed (P1) and an open position (P2) depending on the control signal, wherein the cover element (2) in the closed position (P1) closes at least one opening (3) provided on an end face (S) of the rim facing the environment and the cover element (2) in the open position (P2) at least partially releases the opening (3), wherein the control unit is configured to output the control signal to close the cover element (2) depending on a positive vehicle acceleration acting in the longitudinal direction of the vehicle as soon as the vehicle acceleration exceeds a defined acceleration threshold value.wherein the control unit is further configured to determine or receive a cooling requirement for a brake system of a wheel provided with the movable cover element (2) and to execute a control signal to open the cover element (2) such that the cover element (2) exposes a larger area of ​​the opening (3) as the cooling requirement increases, wherein the control unit is further configured to determine or receive a cooling requirement for a brake system of a wheel provided with the movable cover element (2) and to execute a control signal to open the cover element (2) such that the cover element (2) exposes a larger area of ​​the opening (3) as the cooling requirement increases. The vehicle according to the invention is characterized in that the control unit is further configured to process a cooling requirement estimated by means of a simulation model, wherein the simulation model specifies a braking duration,Braking force and at least one cooling curve are used to estimate the cooling requirement; and / or the control unit is further configured to process a cooling requirement determined as a function of the temperature of a component of the braking system, wherein the temperature of the component is detected by a temperature sensor.

Description

[0001] The invention relates to a vehicle with a cover element which is movable relative to a rim of a wheel, according to the type defined in more detail in the preamble of claim 1.

[0002] A reduction in driving resistance and thus a reduction in drive energy consumption is possible by reducing a vehicle's air resistance. Above a certain speed, the influence of the vehicle's wheels on air resistance cannot be neglected. While driving, air flows particularly over the end of a wheel facing away from the vehicle. Since the rim of a typical vehicle wheel is usually not closed, but has alternating spokes and openings, the flow over these elevations and depressions creates vortices. These vortices contribute to an increase in air resistance. While this effect is less pronounced with steel rims due to their more closed design, it is particularly more pronounced with light alloy rims.To reduce aerodynamic drag, it is desirable to make the ambient-facing face of a rim as closed and smooth as possible. However, this can cause problems for brake cooling. A vehicle's mechanical braking system can heat up considerably during operation. These brake components are typically cooled with air. The smaller the opening cross-section of the ambient-facing surface of a rim, the more difficult it is to supply cooling air to the respective braking system, especially with a sufficiently high mass flow.

[0003] Vehicles with adjustable wheel covers are known to solve this problem. This allows the wheel cover to be closed at high speeds, reducing the vehicle's drag. As the brake system temperature rises or the vehicle speed decreases, the adjustable wheel cover can be opened to ensure better heat dissipation from the braking system.

[0004] Such a cover element, which is movable relative to the rim of a wheel and is also referred to below as an adjustable wheel cover, is known, for example, from EP 3 112 205 B1. The adjustable wheel cover is formed here by a type of iris closure. For example, a closure disc which can be rotated about the axis of rotation of the wheel is provided behind one end face of the rim and can be rotated to open and close the openings between the spokes of the rim. The adjustable wheel cover is opened in particular when the vehicle is braking, the vehicle's clutch is depressed, the vehicle is stationary, the vehicle's ignition is switched off, and when the ambient temperature is high. The adjustable wheel cover can be closed depending on the vehicle's speed of travel, so that the corresponding opening cross-section is reduced as the speed of travel increases.To prevent multiple opening and closing cycles in the boundary area between two boundary conditions that require the opening and closing of the adjustable wheel cover, this process can be provided with a hysteresis. The disadvantage of the solution described in the publication is that the opening and closing of the adjustable wheel cover does not correspond to the actual cooling requirements of the vehicle's braking system. This can result in the adjustable wheel cover being opened unnecessarily, preventing the full potential for reducing the vehicle's aerodynamic drag at higher speeds from being utilized.

[0005] Another adjustable wheel cover is also known from EP 1 319 526 A2. This document describes various possible designs for the adjustable wheel cover. A first possibility describes an iris closure similar to that in the previously referenced document. According to a second embodiment, the adjustable wheel cover can have pivotable flaps. The pivot axis of the flaps can either be oriented in the circumferential direction of the rim, so that the flaps are moved in the direction of the wheel's rotation axis or in the radial direction, or the pivot axis of the flaps can run radially, so that the flaps can be opened and closed in the circumferential direction of the rim. According to a further embodiment disclosed in the document, the rim can also be provided with a cover that can be translated in the direction of the wheel's rotation axis.The cover can be equipped with air deflectors to direct the air flowing toward the wheel to the components to be cooled. The adjustable cover can be adjusted depending on the temperature measured in the wheel area and the vehicle's speed.

[0006] DE 10 2017 102 538 A1 discloses a vehicle with an airflow control device for controlling a wheel lock, which is capable of opening and closing an opening between spokes of a vehicle wheel depending on a driving condition. When the driving condition is accelerated, the control unit activates an actuator to move the wheel lock to the closed position. The present invention is based on the object of providing an improved vehicle with at least one cover element that is movable relative to a rim of a wheel or at least of providing an alternative solution for such a vehicle.

[0007] According to the invention, this object is achieved by a vehicle having a cover element movable relative to a wheel rim according to the features of claim 1. Advantageous embodiments and further developments emerge from the dependent claims.

[0008] A generic vehicle with a cover element that is movable relative to a rim of a wheel and at least one actuator, wherein the actuator is designed to receive an actuating signal from a control unit and to move the cover element between a closed and an open position as a function of the actuating signal, wherein the cover element in the closed position closes at least one opening provided on an end face of the rim facing the environment and the cover element in the open position at least partially releases the opening, is further developed in that the control unit is designed to output the actuating signal as a function of a positive vehicle acceleration acting in the vehicle longitudinal direction.While it is known to control such a cover element, which is movable relative to the rim of a wheel, as a function of negative vehicle acceleration—in other words, when the vehicle is braking—it is not possible to control it as a function of positive vehicle acceleration. If the vehicle accelerates, i.e., if the vehicle's speed increases, this also indicates the need to control a correspondingly adjustable cover element. As the vehicle's speed increases, a higher cooling air mass flow can be supplied to a corresponding braking system of the vehicle, making such a situation suitable for opening the cover element. On the other hand, this increases the vehicle's air resistance, making it suitable for closing the cover element in such a situation.Taking into account the cooling requirements of the vehicle's braking system, the cover element can in particular be closed when the vehicle is accelerating if there is no or only a low cooling requirement and opened when, on the other hand, there is a high cooling requirement. This will be discussed in more detail below. In particular, all wheels of the vehicle are provided with such an adjustable wheel cover. The wheel cover or the cover element is at least partially integrated into the rim or mounted on the rim as a separate component. In the present context of the application, the adjustable wheel cover is preferably understood to mean the one or more cover elements themselves; alternatively, the wheel cover can comprise further components in addition to the adjustable cover element(s), such as a frame, adjustment mechanism or actuators. All common types of actuators for imparting a movement or actuating force to the cover element are possible, such as electromotive, hydraulic, pneumatic or magnetic actuation.

[0009] The vehicle can be any road vehicle such as a car, truck, van, bus or the like.

[0010] The control unit is configured to output a control signal suitable for closing the cover element as soon as the vehicle's acceleration exceeds a specified acceleration threshold. As the vehicle accelerates, its speed increases, thereby increasing the proportion of the total air resistance caused by the airflow to the vehicle's wheels. Advantageously, the cover element is closed when the vehicle accelerates, thus preventing an excessive increase in air resistance. The increased speed also increases the flow velocity of the air flowing toward the wheel, so that a decrease in the cooling air mass flow supplied to the cooling brake system via corresponding openings can be at least partially compensated for by reducing the cross-sectional area of ​​the opening.

[0011] Different values ​​for the acceleration threshold are possible, such as 0 m / s 2 , 1 m / s 2 , 5 m / s 2 , 10 m / s 2 or fractions or multiples thereof. Taking into account an acceleration threshold of 0 m / s 2The adjustable cover element can be closed as soon as acceleration is detected. Taking higher acceleration thresholds into account, certain vehicle accelerations can be permitted before the adjustable cover element is closed. The cover element can be positioned in stages or freely between the closed and open positions. This allows the cover element to be positioned depending on the current vehicle acceleration or, if necessary, taking into account another or different influencing factor in order to set the desired opening cross-section for the respective driving situation for the opening that is at least partially closed by the cover element.

[0012] Furthermore, the control unit is further configured to determine or receive a cooling requirement for a braking system of a wheel provided with the movable cover element and to execute a control signal for opening the cover element in such a way that the cover element exposes a larger proportion of the opening as the cooling requirement increases. This enables particularly efficient operation of the adjustable wheel cover or cover element. Taking into account the cooling requirement of the braking system, the actually required air mass flow can be supplied to the braking system. For example, the brake caliper, a brake block or a brake lining, or even a brake disc of a mechanical braking system can be specifically supplied with air. The cover element is only opened far enough to ensure that the required cooling air mass flow meets the cooling air mass flow demanded by the cooling requirement.This prevents excessive opening of the cover element, thus preventing an excessive increase in the vehicle's drag coefficient due to the cover element being opened. The control unit can determine the cooling requirement for the braking system independently or receive it from a computing unit connected to the control unit. The cooling requirement can be estimated by the control unit or said computing unit, for example, using a computer model, or calculated using suitable sensor values.

[0013] According to the invention, the control unit is further configured to process a cooling requirement estimated by means of a simulation model, wherein the simulation model uses a braking duration, braking intensity, and at least one cooling curve to estimate the cooling requirement; and / or the control unit is further configured to process a cooling requirement determined as a function of a temperature of a component of the braking system, wherein the temperature of the component is detected by a temperature sensor. By taking into account the braking duration, braking intensity, and the at least one cooling curve, the cooling requirement of the braking system can be estimated particularly accurately. Different cooling curves can be taken into account, in particular by varying the component of the braking system under consideration, the supplied cooling air mass flow, the temperature of the cooling air mass flow, the rotational speed of the brake disc, and the like.To determine the cooling requirement, the temperature of a particular component of the braking system can also be taken into account, either additionally or optionally. The current temperature of the respective component can be used to calculate or estimate a cooling requirement independent of the simulation model, or it can be incorporated into the simulation model itself. A cooling requirement can also be determined that takes into account both the cooling requirement estimated using the simulation model and the cooling requirement determined based on the temperature of the braking system component. The selection of the procedure for determining the cooling requirement can be situation-dependent or based on statistical considerations, such as calculating an average of both cooling requirements.

[0014] According to a further advantageous embodiment of the vehicle according to the invention, the control unit is further configured to output a control signal for moving the cover element into the open position as a function of a driving state, to detect the temperature of a component of a braking system of a wheel provided with the adjustable wheel cover, i.e. with the movable cover element, and to output a control signal for moving the cover element from the open position to the closed position as soon as the temperature of the component of the braking system falls below a predetermined threshold value. The driving state describes the speed at which the vehicle is moving. This can be, for example, a standstill or slow travel.Slow travel is characterized by a relatively low speed, such as touch speed, walking speed, or even a higher speed such as 10 km / h or 20 km / h. In particular, slow travel is characterized by the fact that the contribution to the total air resistance caused by the airflow around the wheels is negligible. Thus, even when stationary or traveling slowly, it can be advantageous to close the opening using the cover element. This prevents contamination of parts of the adjustable wheel cover, ensuring more reliable operation.

[0015] Especially during high-speed driving, the adjustable wheel cover or the respective cover element is closed. This prevents dirt from entering the opening. However, if the cover element is open during relatively high-speed driving, there is a high probability that any dirt will be removed by the incoming airflow. This is not possible during slow driving or when stationary. Taking the temperature of the braking system components into account, the system ensures that the cover element is only closed when the braking system is sufficiently cooled or ensured.

[0016] A further advantageous embodiment of the vehicle according to the invention further provides that the control unit is configured to output a control signal for moving the cover element into the open position when the vehicle doors are locked.

[0017] When the vehicle is stationary, especially for a comparatively long period of time, the cooling process of the braking system components slows down due to the lack of airflow. In this case, the cover element(s) are preferably opened to allow sufficient cooling of the braking system components based on natural convection. The locking of the vehicle doors is an indication that the vehicle has been parked in a suitable parking area and not, for example, stopped at a red light. If the vehicle is on the road, for example in front of the traffic light, there is an increased potential for dirt to enter through these openings. If, on the other hand, the vehicle is parked in a parking area, the risk of dirt being entered is lower, so it is possible to open the cover element without danger.Alternatively, it would also be possible to move the cover element to the closed position when locking the vehicle doors. However, this would prolong the cooling process of the brake system.

[0018] According to a further advantageous embodiment of the vehicle according to the invention, the actuator is further configured to receive a second actuating signal for moving the cover element into the open position, wherein the actuator gives priority to the second actuating signal over the actuating signal, wherein the control unit is further configured to output the second actuating signal depending on an active driving mode and / or a current location of the vehicle. The originally output actuating signal can be bridged by means of the second actuating signal. It is also possible for the second actuating signal to be output instead of the (original) actuating signal. If the actuating signal would cause the cover element to close, this is prevented by the second actuating signal or the cover element is even opened further.This is necessary when the vehicle is in a driving mode that results in greater use of the braking system, such as a sport mode or a race track mode. Additionally or alternatively, the vehicle's location can also be taken into account when outputting the second control signal. The vehicle can determine its current location, in particular, with the help of a navigation system. Such a navigation system can have a receiver for a global navigation satellite system in order to determine the vehicle's geoposition using a GPS signal, for example. By comparing the vehicle's location with a digital road map, it can then be determined, for example, whether the vehicle is on a race track.When the vehicle is used on a racetrack, it can be assumed that the vehicle's braking system requires increased cooling, so the cover element is preferably moved to the open position. Locations where the second control signal is to be issued can be stored in the digital map data using a so-called "geofence."

[0019] Particularly when the vehicle is used on a race track, additional information which influences the aerodynamics of the vehicle, for example the degree of opening of the cover element and a lap time, can be taken into account in order to predictively adjust the position of the cover element. In this way, sections of the race track can be identified which are associated with higher or lower driving speeds and higher or lower cooling requirements of the braking system. This enables particularly effective adjustment of the position of the cover element so that the optimal proportion of the area for the opening is set in each case. This makes it possible to reduce the vehicle's air resistance to a minimum whilst guaranteeing safe operation of the vehicle and at the same time ensuring sufficient cooling of the braking system. In particular, an adaptive algorithm can be used to select the position of the cover element orof the free area of ​​the opening, preferably using artificial intelligence.

[0020] A further advantageous embodiment of the vehicle according to the invention further provides that the control unit is further configured to output the actuating signal for executing a predetermined movement cycle for the cover element, wherein the movement cycle provides that the cover element is moved at least once into the open position and at least once into the closed position, and wherein the control unit is further configured to trigger the output of a warning message if the movement cycle cannot be fully executed. The movement cycle can also be understood as the initialization of the adjustable wheel cover. By executing the movement cycle, it can thus be determined whether the adjustable cover element is fully operational or has limited functionality.Depending on the initial position of the cover element, any sequence of opening and closing the cover element is possible. For example, the cover element may originally be positioned in the open position, so that the cover element is first moved to the closed position and then moved back to the open position. In general, the cover element can originally be in any position. The movement cycle stipulates that the cover element is moved at least once into the open position and at least once into the closed position. This ensures that both the open and closed positions can be reached. It also ensures that both opening and closing are possible. This prevents malfunctions, for example due to soiling of the adjustable wheel cover, from going undetected.In the event of such a malfunction, a warning message is then issued. The warning message can be issued in the vehicle itself or on a mobile device linked to the vehicle, such as a smartphone. The warning message can be issued via an acoustic, visual, and / or haptic transmission channel. In particular, the warning message includes information describing which wheel of the vehicle is affected and the extent of the malfunction, i.e., in particular, which position or direction of movement is blocked for the cover element.

[0021] Preferably, the control unit is further configured to repeat the movement cycle if the movement cycle was not fully executed in a previous iteration, in particular by restricting the maximum adjustment range of the cover element. A blockage in the cover element may become unblocked during use of the vehicle. For example, dirt, ice, or other influences that adversely affect the execution of the movement cycle can be removed by the air and / or water flowing around a respective wheel, for example, during rain or when driving through a puddle. Therefore, there is generally a probability that the adjustable cover element will become freely movable again during operation of the vehicle.

[0022] By repeating the movement cycle, this can be determined and the person driving the vehicle can be informed that the adjustable wheel cover is now functional again. In particular, a fixed time period can be specified after which the movement cycle is repeated. The control unit can count up how many times the movement cycle has not been completed. In particular, the control unit can take the prevailing boundary conditions into account, so that, for example, the count is only incremented when the ambient temperature is the same. Advantageously, the maximum adjustment travel of the cover element is restricted between each execution of the movement cycle, thus preventing the cover element from moving into blocked positions and / or with a blocked direction of movement.

[0023] Furthermore, the control unit is preferably further configured to output a control signal for moving the cover element into a defined emergency position after a defined number of incomplete movement cycles. The defined emergency position can in particular be the closed or the open position. It could also be any degree of opening between the closed and the open position. The emergency position can also correspond to the current position of the cover element, so that damage to the adjustable wheel cover can be prevented by a further attempt to move the cover element. In the closed position, the ingress of dirt through the partially or completely exposed opening is counteracted and an excessive increase in air resistance is prevented. In the open position, on the other hand, the greatest possible heat dissipation from the braking system is guaranteed in every driving situation.

[0024] According to a further advantageous embodiment of the vehicle according to the invention, the control unit is further configured to initiate the execution of the movement cycle upon detecting the actuation of a vehicle locking device, upon driving off, and / or upon detecting the actuation of a dedicated operating element. In other words, the movement cycle can be executed automatically before the vehicle is used. This ensures that proper operation is possible before the vehicle is actually used. The movement cycle can also be initiated manually by a user. This allows the user to manually check the proper operation of the adjustable cover element as needed and to demonstrate the adjustable wheel cover to interested parties. The movement cycle can also be executed when locking the vehicle.In particular, a vehicle user is thus able to observe the movement of the cover element by staying outside the vehicle.

[0025] Further advantageous embodiments of the vehicle according to the invention also emerge from the exemplary embodiments which are described in more detail below with reference to the figures.

[0026] Showing: Fig. 1 a schematic representation of an adjustable wheel cover in a closed and an open position; Fig. 2 a flowchart of an operating scheme for controlling the adjustable wheel cover; Fig. 3 is a flowchart of an operating scheme of the adjustable wheel cover when using a vehicle equipped with the wheel cover on a race track; and Fig. 4 a flowchart of an initialization process of the adjustable wheel cover.

[0027] A vehicle according to the invention is provided with a Fig. 1. The adjustable wheel cover 1 comprises a cover element 2 that is movable relative to a rim (not shown in more detail) for closing and uncovering an opening 3 located underneath. The opening is preferably part of the rim and causes an air flow to a brake enclosed by the rim. The wheel cover 1 or the cover elements 2 are at least partially integrated into the rim; alternatively, the wheel cover 1 can be attached to the rim as a separate component. In the exemplary embodiment shown, the opening 3 is designed as an annular gap. The cover element 2 is in turn connected to an actuator (not shown in more detail), which can move the cover element 2 between a closed position P1 and an open position P2.The cover element 2 can be positioned in a stepped or freely adjustable manner between the closed position P1 and the open position P2. A control signal for the actuator is output by a vehicle control unit. By closing the cover element 2 or the opening 3, an increase in the vehicle's air resistance can be counteracted, particularly at high speeds, by reducing or even eliminating the turbulence that occurs on the front side S of the rim facing the surroundings.

[0028] In the Fig. 1, the wheel cover 1 comprises five adjustable cover elements 2, each of which can be moved about a pivot axis running in the circumferential direction of the wheel in the direction of or away from a rotational axis of the wheel. Air guide elements 4 can be arranged in the opening 3 or the annular gap, as shown. The air guide elements 4 can be formed by blades that specifically direct the air entering the opening 3 onto a braking system of the vehicle. The air guide elements 4 can be attached to or molded onto a respective cover element 2. To open the cover element(s) 2, they are moved towards the rotational axis of the wheel or the rim, so that the free cross-section of the opening 3 increases. A sealing material, for example made of an elastomer, can be provided between the cover elements 2.

[0029] By opening the cover elements 2, the air mass flow through the rim that can be supplied to the vehicle's braking system can be increased, which facilitates the heat dissipation from hot components of the braking system.

[0030] In general, other designs of the cover elements 2 are possible, such as an iris-shaped aperture or a cover that can be extended and retracted translationally in the direction of the rotation axis of the wheel and the like.

[0031] Fig. Figure 2 illustrates the process for controlling the adjustable wheel cover 1. In step 201, the control begins with the cover elements 2 being in the open position P2. In step 202, the control unit evaluates relevant input variables, in particular the positive vehicle acceleration. Other variables can be taken into account, such as the cooling requirement for a particular braking system. In step 203, a check is made to determine whether a certain vehicle acceleration is present, preferably whether the vehicle acceleration is greater than 0 m / s. 2If this is not the case, the cover elements 2 do not need to be closed. However, if the vehicle accelerates, the cover elements 2 are moved into the closed position P1. This occurs in step 204. Alternatively, it would also be possible not to completely close the respective cover elements 2, but only to partially close the opening 3. In states 205 and 206, the cover elements 2 are in the aforementioned closed or partially closed position.

[0032] In step 207, the vehicle's driving mode is changed, specifically to a sport mode or racing mode. In step 208, the control unit checks whether said racing mode is active. If this is not the case, no further steps are necessary. If, however, racing mode is active, the cover elements 2 are opened in step 209. Here, too, the cover elements 2 can be moved to the open position P2 or transferred to a partially open state. In step 210, the control unit checks whether the corresponding driving mode has been ended. If this is not the case, the cover elements 2 are left in the open or partially open position. If this is the case, however, the cover elements 2 are closed again. In step 211, the vehicle's operation is ended. The vehicle acceleration is then 0 m / s. 2Furthermore, another signal from the control unit can be evaluated, for example, whether the ignition or on-board electronics is switched on or off, or whether the vehicle doors are locked. In step 211, the cover elements 2 can be moved back to the open position P2, which also allows for improved heat dissipation from the components of the vehicle's braking system when stationary through the use of natural convection.

[0033] In step 212, the control unit determines a cooling requirement for the vehicle's braking system or receives this from another computing unit in the vehicle. For example, the cooling requirement can be determined and provided in connection with a driver assistance system, such as an ESP. In step 213, the control unit checks whether there is actually a respective cooling requirement. If this is not the case, the cover elements 2 remain in the closed position P1. If, however, there is a cooling requirement, the cover elements 2 are at least partially opened or fully opened in step 214. In step 215, the control unit then checks whether the cooling requirement still exists or no longer exists. Accordingly, the cover elements 2 are left in the at least partially open position or are closed.

[0034] According to an advantageous embodiment of the vehicle according to the invention, the control signal output by the control unit can be overwritten by a second control signal, or the second control signal can be output alternatively. The cover elements 2 can be forced open by means of the second control signal. Fig. 3 shows a possible application when using the vehicle on a race track.

[0035] In step 301, the use of the vehicle on the racetrack begins. It is irrelevant whether the cover elements 2 are open, closed, or partially open. In step 302, the control unit checks whether the vehicle is on a racetrack or at another location for which the second control signal is stored in digital map material. To do this, the control unit can compare a geoposition determined for the vehicle with a digital road map. Corresponding racetracks or locations that require the opening of the cover elements 2 can be defined in the digital map by a so-called geofence.

[0036] In step 303, the control unit determines whether all the boundary conditions required for opening the cover elements 2 are met, i.e., at least whether the vehicle is actually on such a race track. If this is not the case, the control unit returns to step 301. If this is the case, however, the cover elements 2 are opened in step 304. The method can already end in step 305. At this point, the use of the vehicle is terminated, which can be verified by the vehicle acceleration being 0 m / s. 2 and another boundary condition is met, such as turning off the vehicle's ignition or activating a locking device. In step 305, the cover elements 2 remain in the open position P2.

[0037] In state 306, the cover elements 2 remain in the open position P2. In step 307, an algorithm for adjusting the position of the cover elements 2 can be executed. Taking into account the cooling requirements, the aerodynamics of the vehicle, and / or the lap time, the cover elements 2 can be positioned anywhere between the closed position P1 and the open position P2. In step 308, the control unit checks whether such an intermediate positioning is necessary or not. If this is not the case, the cover elements 2 remain open. If this is the case, however, the cover elements 2 are moved to a respective intermediate position in step 309. Finally, in step 310, the control unit checks whether an end to this positioning of the cover elements 2 in the partially open or partially closed position is still necessary or not.

[0038] Fig.Figure 4 shows the initialization process for the adjustable wheel cover. In step 401, the vehicle is locked. The cover elements 2 are in the open position P2. In step 402, a user selects how the initialization process should be initiated, or the control unit reads corresponding information from a memory. For example, the initialization process can be initiated by the user manually operating a control element. Automatic initialization could also occur when the vehicle's central locking system is activated or the vehicle accelerates from a standstill.

[0039] In step 403, a defined movement cycle is carried out for the cover elements 2. This movement cycle provides at least that respective cover elements 2 are moved at least once into the closed position P1 and the open position P2. If the movement cycle was able to be carried out completely in step 404, the wheel cover 1, i.e. the adjustable cover elements 2, are operational. Corresponding information can be output to a user of the vehicle in step 405. If, on the other hand, the movement cycle could not be carried out completely, the adjustable wheel cover 1 is not fully operational in step 406. A corresponding warning message is output to the user of the vehicle in step 407. An attempt can be made to repeat the movement cycle, indicated by an arrow 408. For example, the movement cycle can be repeated every 10 minutes.A fixed number of attempts, for example, six, can be specified for repeating the movement cycle. Additional constraints can be taken into account, such as performing the movement cycle or incrementing an attempt only when certain constraints are met, such as similar ambient temperatures or the temperature of a component of the vehicle's braking system remaining essentially unchanged.

[0040] In step 409, the specified number of attempts was reached. The adjustable wheel cover 1 or the cover elements 2 could therefore not be successfully initialized, even retroactively. Therefore, instead of a warning message, an error message is issued, which is intended to prompt the driver to visit a workshop. Additionally, the cover element 2 can be moved into an emergency position. The error message can be issued permanently or only until the vehicle's ignition or the on-board electronics is switched off. A new initialization process can then be initiated when the ignition is switched on again.

Claims

[1] Vehicle with a cover element (2) which is movable relative to a rim of a wheel and with at least one actuator, wherein the actuator is designed to receive an actuating signal from a control unit and to move the cover element (2) as a function of the actuating signal between a closed (P1) and an open position (P2), wherein the cover element (2) in the closed position (P1) closes at least one opening (3) provided on an end face (S) of the rim facing the environment and the cover element (2) in the open position (P2) at least partially releases the opening (3), wherein the control unit is configured to output the actuating signal as a function of a positive vehicle acceleration acting in the vehicle's longitudinal direction for closing the cover element (2) as soon as the vehicle acceleration exceeds a specified acceleration threshold value, wherein the control unit is further configured to determine or receive a cooling requirement for a braking system of a wheel provided with the movable cover element (2) and to execute an actuating signal for opening the cover element (2) in such a way that the cover element (2) exposes a larger area portion of the opening (3) with increasing cooling requirement, wherein the control unit is further configured to determine or receive a cooling requirement for a braking system of a wheel provided with the movable cover element (2) and to execute an actuating signal for opening the cover element (2) in such a way,that the cover element (2) releases a larger area of ​​the opening (3) with increasing cooling requirements., characterized by , that the control unit is further configured to process a cooling requirement estimated by means of a simulation model, wherein the simulation model uses a braking duration, braking intensity and at least one cooling curve to estimate the cooling requirement; and / or the control unit is further configured to process a cooling requirement determined as a function of a temperature of a component of the braking system, wherein the temperature of the component is detected by a temperature sensor. [2] Vehicle according to claim 1, characterized bythat the control unit is further configured to output a control signal for moving the cover element (2) into the open position (P2) as a function of a driving condition, to detect the temperature of a component of a braking system of a wheel provided with the movable cover element (2) and to output a control signal for moving the cover element (2) from the open position (P2) into the closed position (P1) as soon as the temperature of the component of the braking system falls below a predetermined threshold value. [3] Vehicle according to claim 1 or 2, characterized by that the control unit is further configured to output a control signal for moving the cover element (2) into the open position (P2) when the vehicle doors are locked. [4] Vehicle according to one of claims 1 to 3, characterized byin that the actuator is further configured to receive a second actuating signal for moving the cover element (2) into the open position (P2), wherein the actuator gives priority to the second actuating signal over the actuating signal, wherein the control unit is further configured to output the second actuating signal as a function of an active driving mode and / or a current location of the vehicle. [5] Vehicle according to one of claims 1 to 4, characterized by in that the control unit is further configured to output the actuating signal for executing a predetermined movement cycle for the cover element (2), wherein the movement cycle provides that the cover element (2) is moved at least once into the open position (P2) and at least once into the closed position (P1), and wherein the control unit is further configured to cause a warning message to be output if the movement cycle cannot be fully executed. [6] Vehicle according to claim 5, characterized by that the control unit is further configured to carry out the movement cycle again if the movement cycle has not been fully executed in a previous iteration, in particular by restricting the maximum adjustment path of the cover element. [7] Vehicle according to claim 6, characterized by that the control device is further configured to output a control signal for moving the cover element (2) into a predetermined emergency position after a predetermined number of incomplete movement cycles. [8] Vehicle according to one of claims 5 to 7, characterized by that the control unit is further configured to initiate the execution of the movement cycle upon detecting the actuation of a vehicle locking device, upon starting off and / or upon detecting the actuation of a dedicated control element.

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