Method for operating at least one electromechanical actuator of a motor vehicle and motor vehicle

Abstract

The invention relates to a method for operating at least one electromechanical actuator (2) of a motor vehicle (1), wherein the actuator (2) is designed to convert mechanical power into electrical power which is fed into an energy storage device (3) of the motor vehicle (1) during randomly occurring feed processes according to a feed efficiency defined by a feed operating point of the actuator (2), wherein the start of the feed process is detected by a detection device (10) and when the feed process is started a feed operating point of the actuator (2) is set at a feed efficiency of 50% or less.

Description

Technical Field

[0001] The invention relates to a method for operating at least one electromechanical actuator of a motor vehicle, wherein the actuator is designed to convert mechanical power into electrical power which is fed into an energy storage device of the motor vehicle during randomly occurring feed processes according to a feed efficiency predetermined by a feed operating point of the actuator during operation of the motor vehicle. The invention also relates to a motor vehicle. Background Art

[0002] If random and / or highly dynamic loads are integrated into the electrical energy network of a motor vehicle, the energy fed back into the electrical energy network by these loads must be taken into account, if necessary, in the form of reserve capacity in the energy storage device of the electrical energy network. The reserve capacity is the portion of the total capacity of the energy storage device that is used to accommodate the electrical energy generated by the random actuators. The reserve capacity ensures the stability of the energy network, since the energy network cannot be overloaded due to random and therefore unpredictable feedback processes if the fed-in energy can be absorbed by the energy storage device. However, the reserve capacity has the disadvantage that it reduces the total capacity of the energy storage device that can be used for other purposes.

[0003] Various methods are known from the prior art for processing energy fed into the onboard power supply system of a motor vehicle.

[0004] Document KR 20180008970 A describes a device by which the braking current fed into the onboard power system of a motor vehicle is controlled. In the event of insufficient charging capacity of the battery cells of the energy storage device of the motor vehicle, the bridging device of the device is actuated so that the braking current is converted into heat via an impedance. This prevents feeding into bridged / short-circuited battery cells.

[0005] A method for charging a battery is known from document CN 105818708 A. Here, if the temperature of the energy storage device is below a predetermined limit value, current generated by an electric motor connected to the battery is fed to a heating device. Alternatively, if the limit value is exceeded, current is fed into the battery.

[0006] Document DE 10 2016 117 153 A1 discloses a method for regulating a vehicle battery of a hybrid vehicle having an electrically driven cooling system. If the temperature of the battery is above a predetermined threshold value, at least a portion of the current generated by the electric machine during regenerative braking operation is not fed into the battery but is directed to the cooling system in order to cool the battery. Summary of the invention

[0007] The object of the present invention is to provide a method which enables a reduction in the reserve amount in the capacity of an energy storage device.

[0008] To achieve this object, the invention provides for a method of the type mentioned at the outset that the start of the feed process is detected by a detection device and that at the start of the feed process a feed operating point of the actuator is set / adjusted at which the feed efficiency is 50% or less.

[0009] This advantageously makes it possible to convert only a small portion of the mechanical power acting on the actuator into electrical power due to the low feeding efficiency. This reduces the electrical power supplied to the energy storage device of the motor vehicle or the onboard power system of the motor vehicle including the energy storage device during the feeding process. This also reduces the reserve that must be provided in the energy storage device to absorb power. Advantageously, even if there is no reserve or a very small reserve in the energy storage device, this can achieve stability of the energy storage device or the onboard power system of the motor vehicle including the energy storage device.

[0010] In this case, an electromechanical actuator of a motor vehicle is connected to an energy storage device, for example, via the onboard power supply system of the motor vehicle, so that during a feeding process, electrical energy can be transferred from the actuator to the energy storage device. The feeding process of the electromechanical actuator occurs randomly, wherein the term "random" here means that the timing and the number or frequency of the feeding processes are not determined or directly determined by the motor vehicle. This can be caused, for example, by the occurrence of the corresponding feeding process due to unpredictable and / or undetected or undetectable factors acting on the motor vehicle. Random feeding processes can occur in particular in actuators that are not used for vehicle propulsion and are not the power motor of the motor vehicle.

[0011] The electromechanical actuator is therefore preferably different from the motor drive of the motor vehicle. In the case of the motor drive of the motor vehicle, random feed processes generally do not occur, since the motor drive operates as a motor or generator in a deterministic manner and thus in a control device designed to operate the motor it is known at any time which operating state is present or which operating state is to be set when the operating parameters are subsequently changed. An actuator of this type can be, for example, an adaptive damping device or an adaptive chassis damper, but can also be any other actuator different from the motor drive.

[0012] The start of the feed process can be detected by the detection device, so that the start of the feedback of electrical power by the actuator into the vehicle power system can be determined before the electrical power or at least the main part of the electrical power is fed into the energy storage device and / or generated by the actuator. If the start of such a feed process is detected by the detection device, a feed operating point of the actuator is set, at which the feed efficiency is 50% or less. In this case, the feed efficiency indicates the proportion of the mechanical power that is converted into electrical power. In the case of a feed efficiency of 50%, half of the mechanical power of the actuator is converted into electrical power. The remaining half is converted into thermal power, which, for example, causes a heating of the actuator. A feed efficiency of less than 50% therefore means that a higher thermal power is generated from the mechanical power than the electrical power.

[0013] The feed efficiency can also be considered to be related to the conversion of mechanical energy into electrical energy or thermal energy, because for all three energy forms, the time for the generation or conversion of the corresponding power is the same or corresponds to the duration of the feed process. Therefore, the feed efficiency can also be considered as the proportion of mechanical energy that is converted into electrical energy by the actuator, while the remaining proportion is converted into thermal energy or heat.

[0014] The thermal power generated due to the low feed efficiency causes heating of the actuator and / or components coupled to the actuator and therefore does not have to be absorbed by the energy accumulator. The thermal power is absorbed by the thermal capacity of the actuator and other components of the motor vehicle connected to the actuator. As a result, the remaining portion of the fed-in electrical power is significantly lower than the fed-in electrical power in the case of a higher feed efficiency, so that the portion of the total capacity that must be provided as a reserve in the energy accumulator can be advantageously reduced. This increases the capacity available for other functions of the energy accumulator, in particular for extracting energy from the motor vehicle's power motor.

[0015] Furthermore, it is achieved that randomly occurring feed processes of the actuator do not lead to a load exceeding a limit value for the energy store or the onboard power system comprising the energy store and the at least one actuator. By avoiding random or non-deterministic limit value exceeding during the feed process of the electromechanical actuator, instabilities in the onboard power system can be avoided. Thus, increased component loads and / or other critically affecting states can also be avoided.

[0016] By reducing and / or eliminating the reserve, the energy storage device has a greater available capacity, which leads in particular to an optimization of the regeneration phase of the motor vehicle. This can advantageously improve the CO2 potential and the overall efficiency of the motor vehicle, since a greater capacity of the energy storage device is available for other functions, in particular for absorbing the electrical power or energy generated in the regeneration operation of the power unit of the motor vehicle.

[0017] The feed operating point can be set as a function of the desired mechanical properties of the actuator during the feed process and / or the actuator parameters to be adjusted. In this way, the mechanical properties of the actuator at the feed (operating) point can be predetermined. In this case, the mechanical properties of the actuator can also be produced with a reduced feed efficiency. In this case, the desired mechanical properties of the actuator and / or the actuator parameters to be adjusted can be determined, for example, by a control device that is configured to carry out the method or can be transmitted to such a control device from another controller.

[0018] According to the invention, it can be provided that at the set feed operating point, the feed efficiency is 25% or less. The feed efficiency at the set feed operating point can also be in particular 20% or less, 15% or less, 10% or less, 5% or less, 2% or less, or 1% or less.

[0019] Preferably, the feed efficiency is selected to be as low as possible, so that the electrical power generated during the feed process or the electrical energy generated during the feed process is kept as low as possible. Particularly preferably, the feed efficiency is 0% or at least substantially 0%, so that the total mechanical power acting on the actuator is converted into thermal power by the actuator and no or almost no electrical power has to be fed into the energy storage device. The lower the feed efficiency during the feed process, the smaller the reserve in the energy storage device for the at least one electromagnetic actuator can be implemented. At a feed efficiency of 0%, the reserve can be completely omitted.

[0020] In a preferred embodiment of the present invention, it can be provided that an actuator is used which is configured to operate at at least one corresponding actuator operating point during the operation of the motor vehicle during the actuator operation process, wherein the operating efficiency of the actuator for converting electrical power into mechanical power is correspondingly predetermined by the actuator operating point and the operating efficiency is correspondingly 80% or higher.

[0021] The operating efficiency relates to the conversion of electrical power into mechanical power, wherein the portion of electrical power that is not converted into mechanical power is correspondingly converted into thermal power in the actuator. Preferably, the operating efficiency of the actuator during actuator operation is selected to be as high as possible, wherein the operating efficiency is preferably 80% or more. In this way, during actuator operation, at least one actuator can be operated as efficiently as possible by the energy accumulator, so that the electrical power drawn from the energy accumulator can be optimally converted into the mechanical power required for realizing the required actuator function, and unnecessary drawing of energy from the energy accumulator for the actuator operation of the actuator can advantageously be avoided. Corresponding to the feed operating point, the actuator operating point can also be selected as a function of the desired mechanical properties of the actuator.

[0022] According to the invention, it can be provided that the duration of the feed process generated by the actuator during operation of the motor vehicle is 10 ms or less, in particular 1 ms or less, and / or that the mechanical power convertible by the actuator during the feed process is 1 kW or more. It is particularly useful to use a feed efficiency that is as low as possible in particular in the case of electromechanical actuators, which feed into an electrical energy storage device with high dynamics, i.e. with relatively short feed durations. In addition, in such actuators, the required reserve is particularly large if relatively large mechanical powers of 1 kW or more can be converted into electrical power during the feed process and can therefore be fed back into the energy storage device.

[0023] In a preferred embodiment of the present invention, it can be provided that an electromechanical actuator is used, which is connected to an energy storage device via a control device, wherein the feeding operating point of the electromechanical actuator is set by the control device. For this purpose, the control device can be connected to a control device configured to execute the method according to the present invention or include such a control device. The control device can be implemented, for example, as a converter, by which a direct current drawn from the energy storage device can be converted into an alternating current for operating the electromechanical actuator during the operation of the actuator, or the alternating current generated by the electromechanical actuator can be converted into a direct current during the feeding process. In this case, the actuator can be implemented as an electric motor, such as a rotary piston motor or a linear motor.

[0024] According to the invention, it can be provided that an adaptive damping device, in particular an adaptive chassis damper, is used as the electromechanical actuator. An adaptive damping device, for example an adaptive chassis damper, can be used to generate a deflection of the damping device in the actuator operating point. During the feed process, the damping device is compressed or shortened, for example, so that the conversion from mechanical power to electrical power takes place inversely to the movement in the actuator operating point.

[0025] An actuator designed as an adaptive damping device or adaptive chassis damper can include, for example, an electric motor. In addition, such an actuator can also include further elements, such as one or more springs and / or one or more mechanical components, such as compressible or extendable connecting rods, pistons, etc. The feed operating point can be set in the adaptive damping device or adaptive vehicle damper according to the damping characteristic to be set.

[0026] Adaptive chassis dampers and / or other adaptive damping devices of the motor vehicle acting as electromechanical actuators can be controlled as a function of the current driving state of the motor vehicle. The elastic compression or feed process of the electromechanical actuator also occurs as a function of the current operating state, wherein the elastic compression or feed process is random and cannot be predicted by the control device of the motor vehicle with regard to the time and / or frequency of the occurrence of the elastic compression or feed process and / or the corresponding mechanical power to be converted.

[0027] This is especially true because adaptive damping devices, in particular adaptive chassis dampers, can be excited by road surface irregularities during the driving of the motor vehicle. In particular, the elastic compression processes associated with the energy input into the energy storage device depend greatly on the time and frequency of their occurrence and the mechanical power consumed by the actuators. Advantageously, the method can be used in a plurality of adaptive damping devices of a motor vehicle, for example in four adaptive chassis dampers assigned to the wheels of the motor vehicle.

[0028] According to the invention, a current measuring device can be used as a detection device, wherein the current generated by the actuator during the feeding process can be measured by the current measuring device. By measuring the current generated by the actuator, the start of the feeding process can be detected, so that the feed operating point of the actuator can be set, for example, by controlling a control device connected to the actuator. The current measuring device is also advantageously used during the operation of the actuator and in this case in particular for adjusting the actuator operating point, so that no additional sensor is required as a detection device.

[0029] According to the invention, it can be provided that when the start of the feeding process is detected, the torque to be adjusted by the actuator is determined by the actuator control device assigned to the actuator, wherein the feeding operating point is set according to the determined torque. Depending on the design of the actuator, the actuator control device can be, for example, a chassis control device or a damping device control device. The actuator control device can determine the torque to be adjusted or received by the actuator, for example, according to the current driving state of the motor vehicle and / or according to at least one measured value of the detection device when the start of the feeding process is detected. Correspondingly, the torque to be adjusted at the actuator operating point can also be determined by the actuator control device, which torque is generated by the actuator when the actuator operating point is set.

[0030] Provision is made for a motor vehicle according to the invention that the motor vehicle comprises at least one electromechanical actuator, an energy storage device, a detection device and a control device, wherein the actuator is designed to convert mechanical power into electrical power which is fed into the energy storage device during randomly occurring feed processes during operation of the motor vehicle according to a feed efficiency defined by a feed operating point of the actuator, wherein the start of the feed process can be detected by the detection device, and wherein the control device is set up to carry out the method according to the invention.

[0031] According to the invention, it can be provided that the energy storage device is a traction energy storage device and / or the motor vehicle is a hybrid electric vehicle or a fully electric vehicle. In hybrid electric vehicles, which include a power unit in the form of an internal combustion engine in addition to the power motor, an electric energy storage device with a relatively low total capacity is usually installed, so that it is particularly important to reduce the reserve amount in the energy storage device as a percentage of the total capacity of the energy storage device. In fully electric vehicles, which can only be driven by at least one power motor, energy storage devices with a relatively large total capacity are usually used. In this case, too, it is advantageous to reduce or eliminate the reserve amount, because this increases the available total capacity and thus, in particular, the possible driving range of the fully electric vehicle.

[0032] All advantages and embodiments described above for the method according to the invention apply accordingly to the motor vehicle according to the invention. Conversely, the embodiments related to the motor vehicle according to the invention also apply accordingly to the method according to the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Further advantages and embodiments of the present invention are apparent from the following description of the embodiments and from the accompanying drawings. The accompanying drawings are schematic diagrams, in which:

[0034] Figure 1 shows a schematic side view of an embodiment of a motor vehicle according to the invention,

[0035] Figure 2 shows a block diagram of an embodiment of a method according to the present invention,

[0036] Figure 3 A diagram is shown in which the total capacity of the energy storage device is shown. DETAILED DESCRIPTION

[0037] exist Figure 1 , an embodiment of a motor vehicle 1 is shown. The motor vehicle 1 comprises at least one electromechanical actuator 2, which is implemented as an active chassis damper. The motor vehicle 1 also comprises an energy storage device 3 and a power motor 4. The motor vehicle 1 can be implemented as a fully electric motor vehicle, so that the motor vehicle can be moved only by the power motor 4.

[0038] Alternatively, it is also possible for the motor vehicle 1 to be designed as a hybrid electric vehicle and to additionally comprise an internal combustion engine 5 , which is in particular mechanically coupled to the electric power machine 4 .

[0039] The electrical energy storage device 3 is connected to the electromechanical actuator 2 via a control device 6, wherein the electromechanical actuator 2 can be operated via the energy storage device 3 during the operation of the actuator. For this purpose, the control device 6 can be implemented as an inverter, for example, and can be connected to the electric motor 7 of the actuator 2. The electric motor 7 of the actuator 2 can be implemented as a rotary piston motor or a linear motor. In addition, the actuator 2, which is implemented as an adaptive chassis damper, can include other components, such as springs and / or other mechanical components, such as pistons and / or compressible or extendable connecting rods, which are not shown in the figure for the sake of clarity. Figure 1 Not shown.

[0040] The energy storage device 3 and the control device 6 are connected to each other via the onboard power supply system of the motor vehicle. Depending on the voltage level of the energy storage device, the onboard power supply system can be, for example, a 12V power supply system, a 48V power supply system or a high-voltage onboard power supply system. It is possible that the control device includes a DC voltage converter in order to change the voltage level of the onboard power supply system 8 for the operation of the actuator 2 or the motor 7 of the actuator 2. The actuator 2 or the motor 7 of the actuator 2 is connected to the energy storage device 3 via the onboard power supply system 8.

[0041] In addition to the actuator operation of the actuator 2 in the actuator operating point set by the control device 6, the electrical power of the actuator 2 can also be fed into the electrical energy storage device 3 by the control device 6. In this case, the deflection or movement path of the chassis or the actuator 2 designed as an adaptive chassis damper determines the force direction of the mechanical power and thus determines whether current is fed into the vehicle power system 8 or current is taken from the vehicle power system 8.

[0042] If, for example, the actuator 2 designed as an active chassis damper is elastically compressed due to ground irregularities, a current feed occurs, wherein the mechanical power absorbed in this process is converted into electrical power by the actuator 2 and then fed into the energy storage device 3. However, this is undesirable, since a reserve must be provided in the total capacity of the energy storage device 3 for the electrical power generated on this path, so that the energy storage device 3 of the motor vehicle 1 and / or the onboard power supply system 8 connected to the energy storage device 3 is not overloaded during the feeding process via the actuator 2.

[0043] In order to reduce this reserve in the total capacity of the energy storage device and / or to be able to cancel this reserve, the motor vehicle 1 also includes a control device 9 which is designed to set a feed operating point of the actuator 2 at the beginning of the feed process of the actuator 2, at which the feed efficiency is 50% or less. In this case, the feed efficiency refers to the ratio of the electrical power generated by the actuator 2 to the mechanical power acting on the actuator 2. Correspondingly, efficiency can also be understood as the ratio between the electrical energy generated by the actuator 2 and the mechanical energy absorbed by the actuator.

[0044] In order to be able to detect the start of the feeding process, the control device 9 is connected to a detection device 10 of the motor vehicle 1. The detection device 10 is configured to measure the current generated by the actuator 2 during the feeding process. For this purpose, the current measuring device can, for example, determine the current direction and / or amplitude of the phase current flowing between the control device 6 and the motor 7. In this way, it can be determined whether the current is fed into the vehicle power supply 8 or the energy storage device 8, or whether the current is taken from the vehicle power supply 8 or the energy storage device 8. In particular, the detection device 10 can also be used when setting the operating point of the actuator, so that the detection device used elsewhere can be advantageously used to detect the start of the feeding process.

[0045] exist Figure 2 A flow chart of an embodiment of the method according to the present invention is shown in . Here, step S1 represents the initial state of the method.

[0046] In step S2, the start of a feed process through the actuator 2 is detected by means of a current measurement by the detection device 10. The start of a feed process can occur, for example, if the motor vehicle is elastically compressed at the electromechanical actuator 2 due to uneven terrain during driving. Such elastic compression of adaptive chassis dampers or other damping devices of the motor vehicle 1 occurs randomly and cannot be detected by the control device 9 and / or other control devices of the motor vehicle 1.

[0047] Due to the detection of the start of the feed process, in step S3 a feed operating point of the actuator 2 is set at which the feed efficiency is 50% or less. In this case, for example, when the control device 6 is operated using a d / q transformation, the feed efficiency is determined as a function of the position of the feed operating point in the feedback quadrant. The selection of the feed operating point can also be made as a function of the damping characteristic of the actuator 2 to be set, for example, as a function of the torque to be set by the actuator 2 during elastic compression. The damping characteristic or the torque can be determined, for example, by the actuator control device 15 designed as a chassis control device of the motor vehicle 1, for example, based on the measured values ​​of the detection device 10 at the start of the feed process and transmitted to the control device 9 in step S2 when the start of the feed process is detected. The feed operating point of the actuator 2 can then be set by the control device 6 and thus the damping characteristic or the torque and the feed efficiency of the actuator. As a result, a low feed efficiency does not affect the mechanical properties of the actuator 2 and the function of the adaptive chassis including the actuator 2 is also not affected.

[0048] In order to keep the electrical power generated during the feeding process as low as possible, it can be provided in particular that at a set feeding operating point the feeding efficiency is 25% or less, in particular 20% or less, 15% or less, 10% or less, 5% or less, 2% or less, or 1% or less. The feeding efficiency can in particular also be 0% or at least substantially 0%, so that during the feeding process all or almost all of the mechanical power of the actuator 2 is converted into thermal power.

[0049] The actuator 2 and / or other components of the motor vehicle 1 coupled to the actuator 2 are heated by this thermal power, without any feedback into the energy storage device 3. Due to the short duration of the elastic compression process, even at relatively high mechanical powers, only very low thermal power or little heat is generated, which can be absorbed by the thermal capacity of the actuator 2 and / or the components coupled to the actuator 2 without causing significant heating of the actuator 2.

[0050] In order to set the operating point of the actuator 2, the control device 9 drives the control mechanism 6 so that the actuator 2 is operated at the feed input point during the feed process. After the feed process is completed, the method returns to the first step S1. Here, the end of the feed process can also be determined by the control device 9 through the detection device.

[0051] Furthermore, it is also possible to control the electromechanical actuator 2 in the actuator operation starting from the state S1. The control can be determined, for example, by the actuator control device 15 of the motor vehicle 1, which is designed as a chassis control device, and transmitted to the control device 9 in step S4. In order to control the actuator 2 for carrying out the actuator operation process, the actuator 2 is now operated by the control device 9 in the actuator operation working point in step S5. For this purpose, the control device 9 can control the control mechanism 6 of the actuator 2 in order to set the actuator operation working point in the actuator 2. In this case, the actuator has an operating efficiency of 80% or more in the actuator operation working point. In this case, the operating efficiency indicates the proportion of electrical power obtained by the actuator 2 or the proportion of energy converted into mechanical power or energy by the actuator 2. After the actuator operation process is terminated, the method returns to step S1 and the above steps can be executed again from here.

[0052] In particular, it is possible for the motor vehicle 1 to have more than one electromechanical actuator 2 designed as an active chassis damper. It is also possible for the electromechanical actuator 2 to be designed as another type of damping device and / or for the motor vehicle 1 to include further electromechanical actuators designed as damping devices, which are operated by means of the above-described method. In particular, an electromechanical actuator can be operated by means of the method, which during operation of the motor vehicle 1 has a random feed process duration of 10 ms or less, and in particular 1 ms or less, and / or by which a mechanical power of more than 1 kW or more is generated during the feed process. It is possible for the control device 9 and the actuator control device 15 to be designed as a common control device.

[0053] The actuator 2 designed as an active chassis damper can absorb 6 kW of mechanical power, for example, when driving over uneven road surfaces during operation of the motor vehicle 1. When a high feed efficiency is set, for example 83%, 5 kW of electrical power will be generated and fed into the energy storage device 3. For this energy absorption, a reserve must be provided in the energy storage device 3.

[0054] exist Figure 3 Schematically shown in FIG. 1 is a total capacity 11 of the energy storage device 3 . The total capacity 11 is shown here as an area above an axis 14 , wherein the charge states of the energy storage device 3 between 0% and 100% of the total capacity of the energy storage device 3 are schematically plotted on the axis 14 .

[0055] The total capacity 11 has two reserves 12, 13, wherein the lower reserve 12 limits the maximum electrical energy that can be taken from the energy storage device 3 to a lower limit, i.e., to a value greater than 0%. The energy reserved by the reserve 12 can be used, for example, for actuator operation of the actuator 2 of the motor vehicle 1 and / or for the operation of other actuators. The reserve 13 limits the maximum power that can be fed into the energy storage device 3, for example, in the regenerative operation of the power motor 4, to a value below 100% of the total capacity 11 of the energy storage device 3. By means of the reserve 13 for energy absorption, overcharging of the energy storage device 3 and the onboard power supply system 8 is avoided when, in particular, transient feedback currents occur during the feeding process of the actuator 2. In this case, the total capacity reserved by the reserves 12, 13 as a whole can be based on the maximum energy that can be absorbed or discharged on a time average basis and, if necessary, also includes a safety factor accordingly.

[0056] In the method according to the invention, the electrical power that can be absorbed in the feed operating point is reduced by using a low feed efficiency. At a mechanical power to be absorbed of 6 kW and an exemplary feed efficiency of 16% at the feed operating point, the generated electrical power can be reduced to 1 kW, so that the reserve 13 in the energy storage device can be reduced, since overall only less energy can be transferred to the energy storage device 3 during the feed process.

[0057] Advantageously, the efficiency during the feeding process can be selected to be as low as possible, so that the reserve 13 for taking into account the random feeding process by the actuator 2 can be as small as possible or can be completely eliminated. This increases the available capacity of the energy storage device 3, which can be used for other functions of the motor vehicle 1, such as for the regenerative operation of the electric machine 4. Advantageously, the motor vehicle 1 can thus regenerate more energy during the operation of the motor vehicle 1 and use it for other functions, such as driving operation by the power motor 3. In particular, CO2 emissions can be reduced in motor vehicles 1 with hybrid drive, because more energy is also available for the motor operation of the power motor 4 by a smaller reserve 13 or by eliminating the reserve 13. Accordingly, the maximum driving range can be increased in purely electrically driven motor vehicles 1.

Claims

1. A method for operating at least one electromechanical actuator (2) of a motor vehicle (1), wherein: The actuator (2) is designed to convert mechanical power into electrical power to be fed into an energy storage device (3) of the motor vehicle (1) during randomly occurring feed processes during operation of the motor vehicle (1) according to a feed efficiency defined by a feed operating point of the actuator (2), wherein the start of the feed process is detected by a detection device (10) and at the start of the feed process a feed operating point of the actuator (2) is set at which the feed efficiency is 50% or less in order to reduce the reserve that must be provided in the energy storage device for absorbing power.

2. The method according to claim 1, characterized in that At the set feeding operating point, the feeding efficiency is 25% or less.

3. The method according to claim 1 or 2, characterized in that: An actuator (2) is used which is designed to convert electrical power into mechanical power during operation of the motor vehicle (1) according to an operating efficiency which is determined by an actuator operating point of the actuator (2), wherein during the operation of the actuator the actuator operating point is set accordingly, at which the operating efficiency is 80% or more.

4. The method according to claim 1 or 2, characterized in that: The duration of a feed process generated by the actuator (2) during operation of the motor vehicle (1) is 10 ms or less and / or a mechanical power of 1 kW or more can be converted by the actuator (2) during the feed process.

5. The method according to claim 4, characterized in that The duration of a feed process generated by the actuator (2) during operation of the motor vehicle (1) is 1 ms or less.

6. The method according to claim 1 or 2, characterized in that: An electromechanical actuator (2) is used which is connected to an energy storage device (3) via a control device (6), wherein a feed operating point of the electromechanical actuator (2) is set via the drive control device (6).

7. The method according to claim 1 or 2, characterized in that: An adaptive damping device is used as an electromechanical actuator (2).

8. The method according to claim 7, characterized in that Adaptive chassis dampers are used as electromechanical actuators (2).

9. The method according to claim 1 or 2, characterized in that: A current measuring device is used as detection means (10), wherein the current generated by the actuator (2) during the feeding process can be measured by the current measuring device.

10. The method according to claim 1 or 2, characterized in that: When the start of a feeding process is detected, the torque to be set by the actuator (2) is determined by an actuator control device (15) assigned to the actuator (2), wherein the feeding operating point is set as a function of the determined torque.

11. A motor vehicle comprising at least one electromechanical actuator (2), an energy storage device (3), a detection device (10) and a control device (9), wherein: The actuator (2) is designed to convert mechanical power into electrical power to be fed into an energy storage device (3) during randomly occurring feed processes during operation of the motor vehicle (1), according to a feed efficiency defined by a feed operating point of the actuator (2), wherein the start of the feed process can be detected by a detection device (10), wherein the control device (9) is configured to carry out a method according to any one of claims 1 to 10.

12. The motor vehicle according to claim 11, characterized in that The energy storage device (3) is a power energy storage device, and / or the motor vehicle (1) is a hybrid electric vehicle or a fully electric motor vehicle (1).

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