Method for the recuperation control of an electric vehicle

Abstract

The invention relates to a method for the recuperation control of an electric vehicle, which method comprises at least the following steps: determining a selection parameter for selecting a recuperation stage configuration from a plurality of predefined recuperation stage configurations, wherein each of the predefined recuperation stage configurations has a plurality of predefined recuperation stages which each define a recuperation-induced braking of the electric vehicle on the basis of the speed of the electric vehicle, and wherein the selection parameter is determined on the basis of at least one driving safety indicator and / or a control specification of the driver; selecting a recuperation stage configuration from the plurality of predefined recuperation stage configurations on the basis of the selection parameter; and operating at least one electric drive motor of the electric vehicle on the basis of at least one recuperation stage of the selected recuperation stage configuration.

Description

[0001] METHOD FOR RECOVERY CONTROL OF AN ELECTRIC VEHICLE

[0002] The present disclosure relates to a method for the recuperation control of electric vehicles.

[0003] The disclosure relates equally to a computer program and / or computer-readable medium, a data processing device and an electric vehicle.

[0004] The energy efficiency of electric vehicles is significantly influenced by regenerative braking. In regenerative braking mode, the electric drive operates as a generator to produce electrical energy and feed it into the vehicle's electrical system, particularly for charging the battery and / or powering auxiliary components such as an air conditioning compressor. Regenerative braking can be activated automatically when the electric vehicle is no longer accelerating while driving. The rotor of the electric drive then simply rotates during coasting or active braking and can contribute to energy generation in generator mode.

[0005] Regenerative braking has a significant impact on the braking behavior of an electric vehicle. For example, the regenerative braking system can be set to maximize energy generation, resulting in high deceleration. This can be inappropriate depending on the driving situation and the driver's style. In particular, driving safety can be affected. For instance, strong regenerative braking on very wet or otherwise poor road surfaces can compromise driving safety. Similarly, activating strong regenerative braking during a fast cornering maneuver can be detrimental. Therefore, maximizing energy generation or rapidly activating regenerative braking is not always advisable.

[0006] To resolve the conflict between desired driving characteristics and maximum energy generation, it is conceivable to optimally control the recuperation behavior based on a multitude of relevant vehicle parameters. However, this approach suffers from high complexity and real-time requirements, which clash with the limited computing capacity of electric vehicles. Furthermore, there is a risk of unpredictable adjustments to the recuperation behavior for the driver, which is considered detrimental from both safety and ergonomic perspectives. Alternatively, manual adjustment options could be provided. However, such adjustment options are not suitable for situational adaptations during dynamic ferry operation.

[0007] One objective of the present disclosure is to provide an improved method for the recuperation control of an electric vehicle, which, in addition to maximizing energy generation, allows for dynamic adaptability, particularly with regard to driving safety. Furthermore, the method should require only minimal computing resources from the vehicle.

[0008] 23-3059 ABZ EXA 24.09.2024 The problem is solved by the features of the independent claims. The dependent claims contain further developments of the disclosure.

[0009] The problem, according to one aspect of the disclosure, is then solved by a method for the recuperation control of an electric vehicle, wherein the method comprises at least the following steps: Determining a selection parameter for choosing a recuperation level configuration from several predefined recuperation level configurations, each of which has several predefined recuperation level configurations, each defining a recuperation-induced deceleration of the electric vehicle depending on the speed of the electric vehicle. The selection parameter is determined depending on at least one driving safety indicator and / or a control input from the driver. A recuperation level configuration is then selected from the several predefined recuperation level configurations depending on the selection parameter.The procedure also includes the requirement that at least one electric drive motor of the electric vehicle is operated on the basis of at least one recuperation stage of the selected recuperation stage configuration.

[0010] The method is based on recuperation stage configurations, each with multiple recuperation levels. The recuperation behavior can therefore be set in groups by selecting an entire set of recuperation levels and applying them to the recuperation control. This advantageously allows for consistent recuperation behavior across multiple recuperation levels. Nevertheless, the recuperation behavior can be easily and efficiently varied by changing the selected recuperation stage configuration to, for example, address driving safety aspects or other control requirements.

[0011] In one embodiment, the recuperation levels differ between the recuperation level configurations by a degree of spread. The degree of spread represents a spacing distribution between the recuperation levels of a recuperation level configuration. The recuperation levels can be distributed, in particular, between a first recuperation level with maximum braking effect and a second recuperation level with minimum braking effect, with uniform or uneven spacing. Preferably, a recuperation level is defined identically across all recuperation level configurations. For example, a basic recuperation level can be provided that can be activated independently of the selected recuperation level configuration.

[0012] According to a further embodiment, each of the recuperation stages is assigned to one of several speed ranges of the electric vehicle. The speed ranges preferably differ in a maximum and / or a minimum. For example, the recuperation stages are staggered according to speed, similar to a vehicle transmission, in order to operate the vehicle's recuperation depending on the speed or a control input in the respective assigned recuperation stage. The speed ranges preferably overlap by between 70 and 90 percent. Thus, at a given speed, it is possible to select between the two speed ranges.

[0013] 23-3059 ABZ EXA 24.09.2024 several different recuperation levels can be switched to adapt the recuperation behavior to a current driving situation or a requirement of the driver.

[0014] According to a further embodiment, the recuperation stages within each recuperation stage configuration differ according to a uniform pattern, in particular as follows. In a first recuperation stage, which is assigned to a first speed range, the recuperation-induced deceleration is amplified as a function of speed by a first gradient. Analogously, in a second recuperation stage, which is assigned to a second speed range, the recuperation-induced deceleration is amplified as a function of speed by a second gradient. The second speed range has higher speed values ​​than the first speed range, but the magnitude of the second gradient is lower than the magnitude of the first gradient.In this way, the regenerative braking effect in the first regenerative stage can be more pronounced with increasing speed than in the second regenerative stage, which is preferably intended for a higher speed range. The gradients can change non-linearly with speed.

[0015] The recuperation stage configurations preferably comprise recuperation stages of the same design, in particular as described above, with different speed-dependent braking gradients between the recuperation stages. However, the average magnitude of the braking gradients may differ between the recuperation stage configurations.

[0016] Preferably, each recuperation stage is assigned predefined braking acceleration values ​​that depend on the speed of the electric vehicle and can be maintained at least approximately by the recuperation control. For example, the recuperation-induced braking in the first recuperation stage can be between 0.5 and 1.0 m / s². 2 at a minimum in the first speed range and between 4 and 5 m / s 2 at a maximum of the first speed range. Furthermore, the recuperation-induced deceleration in the second recuperation stage can be between 0.5 and 1.0 m / s². 2 The braking deceleration is typically higher at a minimum within the second speed range. Conversely, at a maximum within the second speed range, the deceleration can be higher, particularly between 2.5 and 3.5 m / s². 2The braking acceleration values ​​can be high compared to conventional combustion engines, thus increasing the energy efficiency of the electric vehicle.

[0017] To reduce the data processing load, it can be implemented that a recuperation level configuration, including its contained recuperation levels, is simply selected and used as the basis for the recuperation control without modification. The specific recuperation level to be applied can also be selected unmodified from the recuperation level configuration, for example, automatically depending on the current speed or a driver input.

[0018] 23-3059 ABZ EXA 24.09.2024 In one example, the driver can select a recuperation level and switch between recuperation levels using paddle shifters on the steering wheel or other input devices. Additionally, the driver can select a recuperation level configuration via a switch or other input devices to control the recuperation behavior across all recuperation levels. Alternatively or additionally to manual selection, it is possible for the selection of the recuperation level configuration, as well as at least one of the recuperation levels, to be changed and / or modified depending on the driving safety indicator and / or the control input.

[0019] In a further embodiment, recuperation stages can be selectively activated for individual drive motors of the electric vehicle. For example, a first electric drive motor of the electric vehicle can be operated based on a first recuperation stage of the selected recuperation stage configuration, and a second electric drive motor can be operated based on a second recuperation stage. The second recuperation stage is, for example, a recuperation stage of the selected recuperation stage configuration that differs from the first recuperation stage. Alternatively, the second recuperation stage can be based on the first recuperation stage and modified depending on the driving safety indicator and / or the control input.

[0020] The selected recuperation stage configuration is preferably based on a coasting recuperation mode of the electric vehicle. In particular, the one or more recuperation stages for the electric drive motors are used exclusively in a coasting recuperation mode for recuperation control.

[0021] According to another embodiment, the driving safety indicator represents at least one of the following operating parameters of the electric vehicle: the traction of the electric vehicle, in particular the road surface; a speed; an acceleration; a steering angle (e.g., based on a lateral acceleration value or a steering wheel angle); and a traffic density. In one example, the driving safety indicator, by detecting high speeds and low steering angles, indicates highway driving, while also detecting a dry road surface and low traffic density. Based on this, a suitable recuperation level configuration can be selected. If driving conditions deteriorate, e.g., during a thunderstorm, the driving safety indicator changes to a different value.Regularly checking the driving safety indicator allows for the selection of a different recuperation level configuration during an update. The multiple recuperation levels can thus be quickly and optimally adjusted to the traffic situation in a single step. Switching between recuperation level configurations can also be initiated by the driver, for example, by moving a switch or by another input command received at a different driver interface.

[0022] 23-3059 ABZ EXA 24.09.2024 According to one aspect of the disclosure, a computer program and / or a computer-readable medium is provided. The computer program and / or the computer-readable medium includes instructions that, when executed by a data processing device, cause the device to perform the method according to the disclosure and / or steps thereof. Optionally, the computer program and / or the computer-readable medium includes instructions that, when executed by a data processing device, cause the device to perform the process steps described as advantageous or optional in order to achieve an associated technical effect.

[0023] According to another aspect of the disclosure, a data processing device is provided for an electric vehicle. The data processing device is configured to perform the method described above. Optionally, the data processing device is configured to perform a method step described as advantageous or optional and / or to implement a method feature in order to achieve an associated technical effect. The described method may be a computer-implemented method.

[0024] According to another aspect of the disclosure, an electric vehicle is comprehensively provided with the data processing device described above. Optionally, the data processing device of the motor vehicle and / or the electric vehicle is configured to perform a process step described as advantageous or optional and / or to implement a process feature in order to achieve an associated technical effect.

[0025] The electric vehicle can generally be designed as a passenger car, preferably powered exclusively by one or more electric drive motors. However, the aspects of the disclosure can also be implemented in other types of electric vehicles, for example, in vehicles that are hybrid, powered by an internal combustion engine and an electric drive motor.

[0026] The revelation is described below in further aspects, purely by way of example, with reference to the characters:

[0027] Fig. 1 shows a schematic flowchart of a process according to one aspect of the disclosure;

[0028] Fig. 2 shows a diagram with a first recuperation stage configuration according to one aspect of the disclosure;

[0029] Fig. 3 shows a diagram with a second recuperation stage configuration according to another aspect of the disclosure;

[0030] 23-3059 ABZ EXA 24.09.2024 Fig. 4 shows a schematic representation of a computer program and / or computer-readable medium according to one aspect of the disclosure; and

[0031] Fig. 5 schematically shows a data processing device according to one aspect of the disclosure.

[0032] In the figures, similar elements are provided with the same reference symbols.

[0033] Fig. 1 schematically shows a flowchart of a method 100 for recuperation control of an electric vehicle (not shown in detail) according to one aspect of the disclosure. The individual method steps 110, 120 and 130 are described below with reference to Figs. 2 to 5.

[0034] In process step 110, a selection parameter is determined that serves to select a recuperation stage configuration from several predefined recuperation stage configurations 30, 32. The first recuperation stage configuration 30 is shown in Fig. 2. It comprises several recuperation stages 12, 14, 16, 18 and 20, each of which is represented as a curve of a recuperation-induced braking deceleration A over a speed V of the electric vehicle. The braking deceleration A is given in the unit m / s². 2and the speed V is given in km / h. The numerical values ​​are merely examples and other values ​​are conceivable, which can also be expressed in other units.

[0035] The recuperation stages 12, 14, 16, 18, and 20 each exhibit a characteristic that decreases with increasing speed V, with the gradients differing between the recuperation stages. For example, the recuperation-induced braking deceleration in the first recuperation stage 12 increases with a higher gradient between 50 and 100 km / h than in the other recuperation stages 14, 16, 18, and 20, whose gradients decrease successively between the recuperation stages (see Fig. 2).

[0036] Each recuperation level (14, 16, 18, 20) can be activated over a specific speed range. For example, the first recuperation level (12) can be activated between a minimum speed of 0 km / h and a maximum speed of approximately 110 km / h. The next higher recuperation levels (14, 16, 18, 20), as indicated by the reference symbols, can be activated successively up to a higher maximum speed. The minimum speeds for recuperation levels 16, 18, and 20 also increase slightly, but over a narrower range between approximately 10 and 25 km / h. These numerical values ​​are merely examples, and alternative extreme values ​​can be defined.

[0037] Curve 22 describes the braking deceleration of the electric vehicle without an activated

[0038] Recuperation stage and without active braking by the electric vehicle's braking system. Curve 22

[0039] 23-3059 ABZ EXA 24.09.2024 accordingly refers to a passive coasting of the vehicle, which is essentially slowed down on a level surface by rolling resistance and air resistance.

[0040] The recuperation stages 12, 14, 16, 18, 20 of the first recuperation stage configuration 30 are evenly spaced from each other with a first spreading coefficient. In contrast, in a second recuperation stage configuration 32, the recuperation stages 12, 14, 16, 18, 20 are spaced from each other with a second spreading coefficient that is higher than the first spreading coefficient (see Figs. 2 and 3). In the second recuperation stage configuration 32, the recuperation stages 12, 14, 16, 18, 20 are spaced further apart and, starting from recuperation stage 12, more closely approximate curve 22. The gradients of the recuperation stages 14, 16, 18, 20 are, on average, lower in the second recuperation stage configuration 32 than in the first recuperation stage configuration 30.In the second recuperation stage configuration 32, recuperation stages 14, 16, 18, and 20 thus define a reduced recuperation-induced braking behavior than in the first recuperation stage configuration 30. However, recuperation stages 12, 14, 16, 18, and 20 are defined consistently between both recuperation stage configurations 30 and 32. The first recuperation stage 12 is identical in both recuperation stage configurations 30 and 32 and can be considered the basic recuperation stage.

[0041] It is understandable that more than two or more than five recuperation stage configurations may be provided. However, a smaller number of recuperation stages is also conceivable.

[0042] Referring further to Fig. 1, the selection parameter for choosing one of the recuperation stage configurations 30 and 32 is determined in process step 110 depending on at least one driving safety indicator and / or a control input from the driver. In process step 120, one of the recuperation stage configurations 30 or 32 is selected depending on the selection parameter and used as the basis for the recuperation control of the electric vehicle. Then, at least one electric drive motor of the electric vehicle is operated based on at least one of the recuperation stages 12, 14, 16, 18, 20 of the selected recuperation stage configuration 30 or 32 (process step 130).

[0043] The electric vehicle's regenerative braking system can be repeatedly activated and deactivated during a journey, depending on whether the vehicle is accelerating or not. The desired recuperation level (12, 14, 16, 18, or 20) can be selected based on driver input, for example, via paddle shifters on a control unit (not shown) within the vehicle. An automatic mode may also be available, which switches to the next higher or lower recuperation level (12, 14, 16, 18, or 20) when predefined speed thresholds are exceeded or fallen below.

[0044] Fig. 4 shows a schematic representation of a computer program and / or computer-readable medium.

[0045] 200 according to one aspect of the revelation. The computer program and / or computer-readable medium 200

[0046] 23-3059 ABZ EXA 24.09.2024 includes instructions 201 which, when the program or instructions 201 are executed by a data processing device 54 (see Fig. 5), cause it to carry out the procedure 100 and / or the steps 110, 120 and 130 of the procedure 100 according to Fig. 1.

[0047] The commands 201 can be in the form of program code written in any code or language, particularly code suitable for regenerative braking control systems in electric vehicles. The computer program and / or computer-readable medium 200 can be or comprise any digital data storage device, such as a USB flash drive, hard drive, CD-ROM, SD card, or SSD. The computer program 200 does not necessarily have to be stored on such a computer-readable storage medium; it can also be accessed via the internet or other means.

[0048] The electric vehicle preferably includes a data processing device 54 for executing the computer program and / or computer-readable medium 200. The data processing device 54 comprises, as hardware components, at least one processor 56, a non-volatile memory 58 (e.g., an SD card), and a memory 60 (e.g., main memory, RAM), see Fig. 5. The computer program and / or computer-readable medium 200 can be permanently stored in the non-volatile memory 58 and loaded into the memory 60 for execution. Additionally, when arranged in the electric vehicle, the data processing device 54 is connected to at least one electric drive motor, which can optionally be operated in recuperation mode, in particular according to one of the recuperation levels 12, 14, 16, 18, or 20 of the selected recuperation level configuration 30 or 32.The data processing device 54 enables the computer-implemented execution of the described method for improved recuperation control.

[0049] 23-3059 ABZ EXA 24.09.2024 Reference List

[0050] 12 First recuperation stage

[0051] 14 Second recuperation stage

[0052] 16 Third recuperation stage

[0053] 18 Fourth recuperation stage

[0054] 20 Fifth recuperation stage

[0055] 22 Braking acceleration without activated recuperation stage

[0056] 30 First recuperation stage configuration

[0057] 32 Second recuperation stage configuration

[0058] 54 Data processing device

[0059] 56 processor

[0060] 58 non-volatile memory

[0061] 60 storage

[0062] 100 procedures

[0063] 110 Determining a selection parameter

[0064] 120 Selecting a recuperation level configuration

[0065] 130 Operating an electric drive motor

[0066] 200 computer program and / or computer-readable medium

[0067] 201 commands

[0068] A braking acceleration

[0069] V speed

[0070] 23-3059 ABZ EXA 24.09.2024

Claims

Claims 1. Method for the recuperation control of an electric vehicle, wherein the method comprises at least the following steps: - Determining a selection parameter for selecting a recuperation level configuration (30, 32) from several predefined recuperation level configurations (30, 32), wherein each of the predefined recuperation level configurations (30, 32) has several predefined recuperation levels (12, 14, 16, 18, 20) that each define a recuperation-induced braking of the electric vehicle depending on the speed (V) of the electric vehicle, and wherein the selection parameter is determined depending on at least one driving safety indicator and / or a control input from the driver; - Selecting a recuperation level configuration (30, 32) from the several predefined recuperation level configurations (30, 32) depending on the selection parameter; and - Operating at least one electric drive motor of the electric vehicle on the basis of at least one recuperation stage (12, 14, 16, 18, 20) of the selected recuperation stage configuration.

2. Method according to claim 1, wherein the recuperation stages (12, 14, 16, 18, 20) differ from each other in a degree of spread between the recuperation stage configurations (30, 32), and wherein the degree of spread represents a distance distribution between the recuperation stages (12, 14, 16, 18, 20) of a recuperation stage configuration (30, 32).

3. Method according to one of the preceding claims, wherein each of the recuperation stages (12, 14, 16, 18, 20) is assigned to one of several speed ranges of the electric vehicle, and wherein the several speed ranges differ from each other in a maximum and / or a minimum and overlap.

4. A method according to one of the preceding claims, wherein in a first recuperation stage (12) which is assigned to a first speed range, the recuperation-induced deceleration is amplified as a function of speed with a first gradient, wherein in a second recuperation stage (20) which is assigned to a second speed range, the recuperation-induced deceleration is amplified as a function of speed with a second gradient, wherein the second speed range has higher speed values ​​than the first speed range, and wherein an amount of the second gradient is lower than an amount of the first gradient. 23-3059 ABZ EXA 24.09.2024 5. Method according to claim 4, wherein the recuperation-induced deceleration in the first recuperation stage (12) is between 0.5 and 1.0 m / s². 2 at a minimum in the first speed range and between 4 and 5 m / s2 at a maximum of the first speed range.

6. Method according to claim 4 or 5, wherein the recuperation-induced deceleration in the second recuperation stage (14) is between 0.5 and 1.0 m / s². 2 at a minimum of the second speed range and between 2.5 and 3.5 m / s 2 at a maximum of the second speed range.

7. Method according to one of the preceding claims, wherein at least one of the recuperation stages (12, 14, 16, 18, 20) of the selected recuperation stage configuration (30, 32) is modified depending on the driving safety indicator and / or the control input.

8. Method according to one of the preceding claims, wherein a first electric drive motor of the electric vehicle is operated on the basis of a first recuperation stage (12, 14, 16, 18, 20) of the selected recuperation stage configuration, wherein a second electric drive motor is operated on the basis of a second recuperation stage (12, 14, 16, 18, 20), wherein the second recuperation stage (12, 14, 16, 18, 20) is preferably based on the first recuperation stage (12, 14, 16, 18, 20) and is modified depending on the driving safety indicator.

9. Method according to one of the preceding claims, wherein the selected recuperation stage configuration (30, 32) is used as the basis for a recuperation operation of the electric vehicle, in particular exclusively.

10. Method according to any of the preceding claims, wherein the driving safety indicator represents at least one of the following operating parameters of the electric vehicle: - the traction of the electric vehicle, in particular the road surface condition; - a speed (V); - an acceleration (A); - a steering angle.

11. Computer program and / or computer-readable medium (200), comprising instructions (201) which, when the program or instructions (201) are executed by a data processing device (51), cause the latter to carry out the method (100) and / or the steps of the method (100) according to any one of claims 1 to 10. 23-3059 ABZ EXA 24.09.2024 12. Data processing device (54) for an electric vehicle, wherein the data processing device (54) is configured to perform the method (100) according to any one of claims 1 to 10.

13. Electric vehicle comprising the data processing device (54) according to claim 12. 23-3059 ABZ EXA 24.09.2024

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