Method for operating a motor vehicle with an electronic steering system

Abstract

The invention relates to a method for operating a motor vehicle with an electronic steering system, and generally relates to a method (50) for operating a vehicle (10) with an electronic steering system (12). The electronic steering system includes at least one steering wheel actuator (32), a steering wheel (30) coupled to the steering wheel actuator (32), a wheel actuator (18), steerable vehicle wheels (14) coupled to the wheel actuator (18), and a control device (42). A control device (42) is coupled to at least the steering wheel actuator (32) and the wheel actuator (18). The control device (42) is configured to control the wheel actuator (18) as a function of the detected steering wheel angle of the steering wheel (30) such that the steerable vehicle wheels (14) assume a wheel angle defined by the detected steering wheel angle as a function of translation and detect erroneous automatic steering of the steering wheel actuator (32). The panning function describes a correlation of the wheel angle to the detected steering wheel angle. As an erroneous automatic steering is detected, a steering wheel angle change is estimated by the control device (42) on the basis of the erroneous automatic steering of the steering wheel actuator (32). At least one compensation measure is triggered such that at least a wheel angle change based on the estimated steering wheel angle change is reduced.

Description

TECHNICAL FIELD

[0001] The present invention relates generally to a method for operating a motor vehicle with an electronic steering system. BACKGROUND

[0002] Electronic steering systems are an emerging steering technology that eliminates the mechanical link between the steering wheel and the wheels and replaces it with two actuators: a feedbacked steering wheel actuator that generates a feedback torque for the driver (on the steering wheel); and a wheel actuator that controls the wheels to the desired position.

[0003] In a steer-by-wire (SbW) system, the required wheel angle (or a corresponding signal, e.g. pinion angle or steering rack travel) is determined and electronically controlled based on the measured steering wheel angle. This calculation represents the simulated steering ratio between the steering wheel and the steerable disc of the vehicle and can be modified in order to provide an optimal ratio for the driver and feedback based on the current vehicle situation (e.g. vehicle speed). The desired feedback torque on the steering wheel is generated by the steering wheel actuator based on an algorithm and vehicle signals. The steering wheel actuator is connected to the steering wheel through the upper steering column.

[0004] If the driver is (at least partially) unable to counteract the torque, the unintentional generation of torque by the steering wheel actuator (“autosteering”) can lead to a spontaneous jerking or increase in steering wheel rotational speed. Since the inertia of the steering wheel actuator is significantly lower compared to a conventional EPS system (electric power steering) and the friction is usually also lower, the resulting increase in steering wheel rotational speed is greater at the same torque. For example, driving situations can occur in which the driver holds the steering wheel very loosely or even takes his hands off the steering wheel (“hands off”).

[0005] The change in steering wheel angle caused by the autosteering of the steering wheel actuator leads to a change in the steering wheel angle command and thus to an unintended steering of the steerable wheels.

[0006] Previous approaches aim to reduce the feedback signal or interrupt signal transmission to the steering wheel actuator for a predefined period of time (DE 10 2016 009 684 A1). Alternatively, the driver's request to steer the vehicle communicated in the signal transmission is only included in the conversion to determine a reduced amount of steering movement of the wheels. Similarly, DE 10 2019 135 047 A1 discloses an electronic steering system with a synchronization monitoring device. A synchronization offset between the steering command corresponding to the steering wheel movement and the wheel actuator can be considered to reduce the influence of the driver's unintentional input due to a steering actuator failure. Furthermore, US 11780493 B2 discloses a reduction of the maximum speed due to a detected error. However, so far, the only approaches taken are those that influence the outcome of later unintended steering wheel movements based on estimations. In other words, previous approaches do not focus on the direct effect of compensating for unintentional steering wheel movements.

[0007] Therefore, there is a need to eliminate or at least reduce the disadvantages in known approaches and electronic steering systems for operating a vehicle with an electronic steering system. In particular, there is a need to design an electronic steering system in such a way that the functionality and comfort of the electronic steering system can be better guaranteed than in previous approaches in case of an erroneous automatic steering of the steering wheel actuator. SUMMARY

[0008] This object is achieved by the subject matter of the independent patent claims. Advantageous embodiments are specified in the dependent claims and the following description, each of which can represent aspects of the present disclosure alone or in (sub-)combination. Some features are explained for a method, other features are explained for a device. However, the relevant aspects can be transferred to each other in a corresponding manner.

[0009] According to one aspect, some embodiments of the present disclosure relate to a method for operating a vehicle with an electronic steering system. The electronic steering system comprises at least one steering wheel actuator, a steering wheel coupled to the steering wheel actuator, a wheel actuator, a steerable vehicle wheel coupled to the wheel actuator, and a control device. The control device is coupled at least to the steering wheel actuator and to the wheel actuator. The control device is designed to control the wheel actuator depending on a detected steering wheel angle of the steering wheel such that the steerable vehicle wheel assumes a wheel angle defined by the detected steering wheel angle according to a translation function. The control device is further configured to detect an erroneous automatic steering of the steering wheel actuator. The translation function describes a correlation of the wheel angle and the detected steering wheel angle. Due to the detection of the erroneous automatic steering, the method comprises at least the following steps:

[0010] - estimating, by the control device, a steering wheel angle change based on the erroneous automatic steering of the steering wheel actuator.

[0011] triggering at least one compensation measure by the control device such that at least the wheel angle change based on the estimated steering wheel angle change is reduced.

[0012] The method is based on the insight that the influence of the erroneous automatic steering of the steering wheel actuator can not only be indirectly compensated in the future by changing the translation function, but also at least immediately mitigated. To this end, the control of the wheel actuator is immediately adjusted accordingly, wherein the influence of the automatic steering is first determined. Thus, by estimating to what extent the erroneous automatic steering of the steering wheel actuator leads to an angle change of the steerable vehicle wheel, a compensation measure becomes possible. While previous methods counteracted the influence of the erroneous automatic steering only by adjusting the feedback to the driver or by adjusting parameters related to the future control of the wheel actuator (and thus neglecting the resulting steering wheel angle change), the present method seeks a more direct approach by immediately modifying the control of the wheel actuator. This means that the influence of the erroneous automatic steering can at least be reduced more directly than before, in particular reduced. Thus, depending on the steering specification of the driver, the vehicle recovers to the desired motion trajectory faster than before, i.e. in a shorter time. This allows a faster compensation of the deviation due to the erroneous automatic steering, thereby increasing the likelihood of laterally guiding the vehicle compared to previous methods. In other words, in the case of an erroneous automatic steering of the steering wheel actuator, a smaller displacement deviation can be guaranteed. This improves the comfort of the driver.

[0013] According to one aspect, some embodiments of the present invention relate to an electronic steering system for a vehicle. The electronic steering system comprises at least one steering wheel actuator, a steering wheel coupled to the steering wheel actuator, a wheel actuator, a steerable vehicle wheel coupled to the wheel actuator, and a control device. The control device is at least coupled to the steering wheel actuator and the wheel actuator. The control device is at least configured to:

[0014] - control the wheel actuator depending on a detected steering wheel angle such that the steerable vehicle wheel assumes a wheel angle defined by the detected steering wheel angle according to a translation function. The translation function describes a dependency of the wheel angle on the detected steering wheel angle.

[0015] - detect an erroneous automatic steering of the steering wheel actuator.

[0016] - estimate a steering wheel angle change based on the erroneous automatic steering of the steering wheel actuator.

[0017] - trigger at least one compensation measure such that at least the wheel angle change based on the estimated steering wheel angle change is reduced.

[0018] The advantages achieved by the methods described herein are also achieved by the electronic steering system in a corresponding manner.

[0019] The steering wheel actuator does not have to be directly coupled to the steering wheel. For example, the steering wheel actuator can also be coupled to a steering wheel shaft (steering column) to which the steering wheel is attached.

[0020] Likewise, the wheel actuator does not need to be directly coupled to the steerable vehicle wheels of the vehicle. For example, the wheel actuator can be coupled to a steering rack of an electronic steering system, which in turn is coupled to the steerable vehicle wheels.

[0021] For example, a failure of the steering wheel actuator can trigger an erroneous automatic steering of the steering wheel actuator.

[0022] Here, the control device is designed as a general control device for the entire electronic steering system. However, alternatively or cumulatively, different control devices can also be provided, which interact with the steering wheel actuator and the wheel actuator.

[0023] The translation function represents an analog coupling between the steering wheel, with which a steering specification is implemented by a vehicle driver, and the steerable wheels of the vehicle. Ultimately, the translation function allows the steering specification of the driver to be appropriately converted into a required lateral guidance of the vehicle. Furthermore, by sending a torque feedback signal to the driver on the steering wheel, the driver can be made aware of information about the current driving situation or road information. This torque feedback signal can be determined on the basis of various types of information, such as the steering wheel angle, the wheel angle, the vehicle speed and / or the steering force of the wheel actuator. Such a torque feedback signal is also described as a torque feedback.

[0024] The erroneous automatic steering results in a movement of the steering wheel. This movement of the steering wheel results in a change in the wheel angle of the steerable wheels of the vehicle. This change in the wheel angle is estimated and at least reduced by the control device of the electronic steering system in the invention.

[0025] In addition to the control device, the actuators can also have an intrinsic actuator control device, which is designed to receive an actuation signal, which defines a desired movement of a mechanical component (e.g. steering wheel, steering column or steering rack) implemented by the respective actuator. The actuator control device can be designed to control the respective actuator accordingly on the basis of the actuation signal received from the control device of the electronic steering system. Each actuator comprises an electric motor, on the basis of which a movement of a mechanical component coupled to the actuator can be implemented. For example, in order to cause a movement of the mechanical component, a respective phase voltage can be applied to the windings of the electric motor. The actual control of the sequence and amplitude of the phase voltages can then be carried out by the actuator control device on the basis of the actuation signal received from the control device. In an alternative, the control device can also be designed to directly control the electric motor on the basis of the actuation signal, i.e. such that the respective phase voltages can be provided directly, for example, from a converter.

[0026] In view of the compensation measure, the control device preferably outputs an actuation signal to the wheel actuator such that at least the wheel angle change based on the steering wheel angle change relative to the erroneous automatic steering is reduced or even compensated. In this regard, the actuation signal adjusted relative to the unmodified configuration is output to the wheel actuator such that the lateral guidance of the vehicle advantageously corresponds more precisely to the steering specification actually specified by the driver (without the erroneous automatic steering).

[0027] Optionally, the compensation measure at least comprises determining the wheel angle change by the control device based on the estimated steering wheel angle change and taking the original translation function into account. This means that the control function using the original translation function can determine how the steering wheel angle change caused by the automatic steering affects the change in the wheel angle during the lateral guidance of the vehicle. Thus, the information base for further compensation measures can be enlarged, for example in order to make appropriate corrections to the lateral guidance of the vehicle.

[0028] Optionally, for determining the wheel angle change, the control device expresses the steering wheel angle change in terms of the erroneous automatic steering with the translation function or a corresponding operating point of the translation function. The translation function describes the typical non-linear correlation (but often also linear correlations are possible) of the steering wheel angle to the steering specification, i.e. the (detected) steering wheel angle. Thus, the translation function usually has a non-linear curve shape. In general, a characteristic curve or a characteristic map as a function of the operating point is used for a related description of the correlation between the wheel angle and the steering wheel angle. Thus, "expressing in terms of" here means taking into account the translation function applicable to a particular operating configuration (operating point) in order to determine the change in the wheel angle based on the change in the steering wheel angle caused by the erroneous automatic steering. In mathematical terms, the "expressing in terms of" can be, for example, a division or a multiplication, depending on the definition of the translation function. This is based on the fact that the product or the ratio of the translation function and the steering wheel angle change results in the change in the wheel angle caused by the change in the steering wheel angle. This allows different electronic steering systems and / or vehicles to be considered with different translation functions, for example, if the dimensions of the respective components such as the steering rack, the steerable wheels or the steering column or the resistance values of the vehicle change. In other words, the change in the steering wheel angle is thus related to the respective specific electronic steering system of each specific vehicle. By considering different translation functions of different electronic steering systems or vehicles, the method can thus be applied to a variety of different electronic steering systems. This increases the versatility of the method.

[0029] Preferably, the electronic steering system can comprise at least one steering wheel sensor configured to detect a position and / or a movement of the steering wheel or of a component coupled thereto, for example a steering column. For example, the steering wheel sensor can be configured to detect a steering wheel rotational speed.

[0030] Optionally, the steering wheel sensor can be part of or coupled with the steering wheel actuator.

[0031] Alternatively, the steering wheel sensor can also be connected to the steering wheel separately from the steering wheel actuator.

[0032] In some embodiments, when estimating the steering wheel angle change based on the erroneous automatic steering, the control device takes into account a diagnostic time interval of the control device. This allows the compensatory measure to adapt to the diagnostic time interval as needed.

[0033] The diagnostic time interval of the control device describes the time interval between the diagnostic start time and the diagnostic end time of a malfunction (erroneous automatic steering), during which the control device determines and triggers the measure (compensatory measure) taken as a result of the erroneous automatic steering. For example, the steering wheel speed can be measured using the steering wheel sensor.

[0034] Preferably, the diagnostic time interval is predefined and constant. If the diagnostic time interval is predefined, the method is particularly compact.

[0035] Alternatively, the diagnostic time interval can be determined by the control device based on the fact that at the diagnostic start time of the diagnostic time interval, the steering wheel speed of the steering wheel is equal to 0 degrees / second (here and below the degrees: in angular units). At the diagnostic end time of the diagnostic time interval, the steering wheel speed will not be equal to zero. In addition, the steering wheel speed of the steering wheel at the diagnostic end time is known, as it is detected by the steering wheel sensor. The diagnostic time interval can now be determined by assuming that the steering wheel speed at the diagnostic end time has been accelerated to the detected steering wheel speed by the steering wheel actuator based on the maximum steering wheel angular acceleration as part of the erroneous automatic steering. This can be used to determine the duration of the diagnostic time interval.

[0036] In another alternative, the diagnostic time interval can be determined by the control device based on the fact that the average steering wheel speed before the diagnostic start time is taken into account, so that the assumption that the steering wheel speed of the steering wheel at the diagnostic start time of the diagnostic time interval is 0 degrees / second can be deviated from. For this purpose, the control device can continuously determine the average of the steering wheel speed. Since the erroneous automatic steering causes a large change in the amplitude of the steering wheel speed, the average of the steering wheel speed determined then will deviate disproportionately from the previous value, the deviation allowing the diagnostic start time to be identified. The diagnostic time interval is then calculated according to the previous method by using the average of the steering wheel speed obtained before the diagnostic start time.

[0037] In another alternative, the control device can be coupled to a memory device in which values of the steering wheel speed of the electric motor of the steering wheel actuator and / or the motor torque are continuously stored. The diagnosis start time can be determined by the stored values of the steering wheel speed by the fact that the automatic steering of the error leads to a large change in the amplitude of the steering wheel speed and / or the motor torque of the electric motor of the steering wheel actuator, so that a large change in the amplitude can be found in the stored values of the steering wheel speed and / or the motor torque, which allows the diagnosis start time to be determined. The diagnosis time interval is then calculated according to the previous method.

[0038] In another alternative, the diagnosis time interval can be determined by the control device based on a steering wheel speed difference of the steering wheel between a diagnosis start time and a diagnosis end time considering the diagnosis time interval. The steering wheel speed difference is determined by the control device based on a non-linear function.

[0039] Alternatively, the steering wheel speed difference is determined by the control device based on a maximum torque that can be applied by the steering wheel actuator to the steering wheel. The maximum torque that can be applied by the steering wheel actuator to the steering wheel determines how fast the steering wheel speed can reach at the diagnosis end time. This allows the duration of the diagnosis time interval to be determined.

[0040] In another alternative, the steering wheel speed difference is determined by the control device based on a detected torque applied by the steering wheel actuator to the steering wheel. The detected torque applied by the steering wheel actuator to the steering wheel determines the speed reached by the steering wheel speed at the diagnosis end time. This allows the duration of the diagnosis time interval to be determined.

[0041] Alternatively, the steering wheel speed difference is determined by the control device based on an estimated maximum torque that can be applied by the steering wheel actuator to the steering wheel. The torque can be estimated, for example, based on motor parameters of the steering wheel actuator, such as the speed, the phase voltage and the phase current. The estimated torque applied by the steering wheel actuator to the steering wheel determines the speed reached by the steering wheel speed at the diagnosis end time. This allows the duration of the diagnosis time interval to be determined.

[0042] The steering wheel speed will typically show a difference between the diagnosis start time and the diagnosis end time. In order to be able to determine the diagnosis time interval, which is typically variable, based on the steering wheel speed difference, the steering wheel speed difference can be used. This method allows different steering wheel speed differences to be taken into account, so that ultimately the diagnosis time interval can be estimated. The different methods allow high variability and also allow the methods to be tested against each other in determining the diagnosis time interval. This improves the reliability of the method compared to the previous methods.

[0043] The torque applied by the steering wheel actuator to the steering wheel can be determined, for example, by the control device, by means of measurements, for example, of the steering wheel sensor.

[0044] For example, the actual output torque or the estimated output torque can be determined or estimated based on parameters of the electric motor of the steering wheel actuator.

[0045] Alternatively, the torque applied to the steering wheel by the steering wheel actuator can also be estimated by the control device, for example, based on a characteristic curve or a characteristic map stored in a memory device coupled to the control device.

[0046] In another alternative, only the maximum torque that can be applied to the steering wheel by the steering wheel actuator (worst case) can be considered. This makes the estimation of the actual steering wheel speed difference particularly compact.

[0047] Therefore, various methods can be employed to determine the actual steering wheel speed difference caused by the erroneous automatic steering of the steering wheel actuator.

[0048] In an alternative, the steering wheel angle and / or the motor torque can be measured and stored in a memory device, for example, the steering wheel angular velocity can be determined indirectly by the control device. For example, the steering wheel angle can be measured using a steering wheel sensor. The respective motor torque here refers to the torque generated by the electric motor when outputting. For example, the motor torque can be determined by the control device based on parameters of the electric motor of the steering wheel actuator. For this purpose, for example, a respective voltage sensor or current sensor and a position sensor can be coupled to the electric motor. The respective sensors can be used to detect the phase voltage, the phase current or the relative position between the rotor and the stator of the electric motor and transmit it to the control device. The control device can then determine the torque generated by the electric motor based on the received measurement values. The respective recorded parameters can be stored as storage values in a data memory coupled to the control device. This further increases the versatility of the method.

[0049] Preferably, the storage values can be recorded continuously for a period of time, which in any case is longer than the diagnostic time interval. This ensures that there are enough storage values to be able to read the respective values of the steering wheel angle and / or the motor torque generated by the steering wheel actuator several times before the erroneous automatic steering occurs, regardless of the length of the diagnostic time interval.

[0050] Optionally, the storage of the respective storage values in the data memory can only be triggered under defined operating conditions of the electronic steering system. For example, it can be necessary for the steering wheel angular velocity or the motor torque generated by the electric motor of the steering wheel actuator to exceed or fall below a respective threshold value. In this regard, the threshold value is used as a trigger for storing the storage values. This avoids the problem of requiring too much storage space for the continuous storage of the storage values. This makes the electronic steering system particularly compact.

[0051] Preferably, the data memory can be frozen if the control device of the electronic steering system triggers a diagnosis of an erroneous automatic steering of the steering wheel actuator, i.e. if a steering wheel angle change based on the erroneous automatic steering has to be estimated by the control device. This can avoid that the continuous recorded measurement values of the steering wheel angle and / or the steering wheel rotational speed and / or the torque output by the electric motor of the steering wheel actuator overwrites the old stored values of the data memory, if the data memory is a rolling data memory, whose entries are continuously overwritten (at least after a certain time interval).

[0052] Optionally, the control device is configured to determine the diagnosis start time by the data memory evaluating a sharp rise of the motor torque output by the electric motor of the steering wheel actuator and / or a large change of the amplitude of the steering wheel angle. The erroneous automatic steering of the steering wheel actuator leads on the one hand to a sudden, spontaneous large change of the amplitude of the steering wheel angle of the steering wheel and on the other hand to a spontaneous rise of the motor torque output by the electric motor. Thus, the diagnosis start time can be determined particularly precisely, if the measurement values stored in the data memory are retrieved to look for the respective features regarding the engine torque and the steering wheel angle.

[0053] Preferably, the size of the unintentional steering wheel angle from the start of the erroneous automatic steering (diagnosis start time) to its detection (diagnosis end time) can be estimated by the control device using the steering wheel angle at the diagnosis start time. The change of the steering wheel angle based on the erroneous automatic steering of the steering wheel actuator can be determined particularly precisely. This also enables the compensation of the effects caused by the erroneous automatic steering with increased precision.

[0054] In an alternative, the steering wheel angle difference between the diagnosis start time and the time of freezing the data memory can be used to estimate the size of the unintentional steering wheel angle. This is another approach to improve the accuracy of determining the effects of the erroneous automatic steering of the steering wheel actuator compared to the previous approach.

[0055] In some embodiments, the compensation measure comprises at least a change of the translation function. In particular, the translation function can be modified depending on the detected steering wheel angle. Due to the modified translation function, the estimated change of the steering wheel angle only leads to a reduced change of the wheel angle size compared to the unmodified translation function. The modified translation function is more indirect than the unmodified (original) translation function. This means that the target value of the wheel angle change determined by the modified translation function can be attenuated compared to the unmodified translation function. This means that the effects of the steering wheel angle change on the lateral guidance of the vehicle caused by the automatic steering can be immediately attenuated or even compensated.

[0056] Preferably, as part of the compensation measure based on the modified translation function, the offset angle caused by the modified translation function is at least partially reduced, preferably compensated. The modified translation function actually leads to an offset of the wheel angle (depending on the detected steering wheel angle) compared to the unmodified translation function. Based on the modified translation function, the offset is at least partially compensated (i.e. reduced) or completely compensated, thus it ensures a reduction (compensation) of the offset. Optionally, the offset angle can be reduced (compensated) over an offset time interval. The offset time interval starts when the translation function is modified. Subsequently, the modified translation function is adapted in such a way that at least during the offset time interval, in particular in a continuous manner, i.e. based on the change in the wheel angle caused by the modified translation function, the offset with respect to the unmodified translation function is compensated. This ensures a comfortable, gradual compensation, thus avoiding sudden changes for the user.

[0057] Preferably, the compensation measure comprises at least one filtering measure of the steering wheel input of the steering wheel. The filtering action allows for an automatic (and continuous) influence on the steering wheel input of the steering wheel. For example, the steering wheel input of the steering wheel can be determined based on the detected steering wheel angle. The filtering measure can then be applied automatically to the detected steering wheel angle, for example, in order to mitigate the influence of the steering wheel input, in particular to smooth it.

[0058] Particularly preferably, the filtering measure comprises a low-pass filtering of the detected steering wheel angle, thus smoothing the influence of the steering wheel input of the steering wheel on the vehicle lateral guidance in particular. This can reduce the size of the influence.

[0059] In some embodiments, the control device is further configured to control the steering wheel actuator based on the detected wheel angle, etc. in such a way that the steering wheel actuator applies a feedback torque to the steering wheel. For steering wheel actuators for which the torque can be restored after fault isolation or for which additional torque can be provided in parallel to the erroneous torque, the following strategies can be considered to reduce the influence of the erroneous automatic steering after detection of the fault.

[0060] Optionally, when the control device controls the steering wheel actuator, the compensation measure can then comprise considering an additional counter torque applied by the steering wheel actuator to the steering wheel or a component coupled thereto, e.g. a steering column, thereby at least reducing the steering wheel rotation speed or steering wheel movement stop caused by the false automatic steering. Preferably, the counter torque is provided in the form of a pulse, which means a characteristic curve with a high, preferably highest, curve in terms of amplitude. Thus, the counter torque is opposite to the torque of the steering wheel angle change caused by the false automatic steering. The counter torque causes the false movement of the steering wheel to be attenuated due to the false automatic steering (compared to a configuration without counter torque), and thus also ensures a possible overreaction of the driver to be reduced (compared to a configuration without counter torque). Reducing the steering wheel rotation speed reduces the size of the false steering angle, and thus the size of the false wheel angle, and thus in turn the severity of the false vehicle response. This also enables the driver to correct the false better, and thus also reduces the deviation from the desired driving path.

[0061] This helps to prevent the vehicle driver from reacting too strongly to the false automatic steering due to the false torque feedback, thereby shortening the time to correct the effects of the false automatic steering. In other words, the driver can compensate for the false vehicle response more quickly.

[0062] Preferably, the control device controls the steering wheel actuator in such a way that the feedback torque applied by the steering wheel actuator to the steering wheel is increased after detecting the false automatic steering compared to the feedback torque of the undisturbed electronic steering system. Here, a characteristic curve of the feedback torque is used, which has a larger amplitude range than the normal curve, but a smaller amplitude range than the characteristic curve used in the background of the pulsed counter torque. This means that the steering wheel actuator is controlled by the control device in such a way that the feedback torque provided to the driver is higher after detecting the false automatic steering compared to the feedback torque provided to the driver before the false automatic steering compared to the undisturbed configuration of the electronic steering system (without false automatic steering). Thus, the driver of the vehicle reacts to a reduced steering specification, so that the effects of the false automatic steering can be corrected more easily compared to without the compensation measures.

[0063] In some embodiments, the control device controls the steering wheel actuator in such a way that an additional damping torque is considered when providing the feedback torque. This also means that the driver will react to a reduced steering specification, which makes it easier to correct the consequences of the false automatic steering compared to without these measures.

[0064] This helps to prevent the vehicle driver from reacting too strongly to the false automatic steering due to the false automatic steering, thereby reducing the severity of the false automatic steering.

[0065] Overall, the method allows to determine the impact of the erroneous automatic steering and to at least immediately partially compensate for it such that only the change in the wheel angle is reduced compared to the case without the control function. Thus, the deviation of the wheel angle in the course of the driving direction can be aligned with its driving direction faster than before without the erroneous automatic steering.

[0066] In some embodiments, the electronic steering system can have at least one wheel sensor configured to detect a wheel angle of a steerable vehicle wheel or a vehicle component coupled therewith.

[0067] Optionally, the wheel sensor and / or the steering wheel sensor can be coupled to the control device and transmit the respective measurement to the control device.

[0068] Optionally, the method is designed as a computer-implemented method. This means that the method steps can be supported by one or more data processing devices. In particular, the data processing devices can trigger or execute the appropriate steps. For example, the data processing device of the control device can estimate a wheel angle change based on the erroneous automatic steering and output a corresponding actuation signal to the wheel actuator in a way that at least reduces the estimated wheel angle change.

[0069] According to another aspect, the disclosure also relates to a computer program comprising instructions which, when the program is executed by a computer, cause the computer to carry out the method described herein. The advantages achieved by the method described herein are also achieved by the computer program product in a corresponding manner.

[0070] According to another aspect, the disclosure also relates to a computer-readable storage medium comprising instructions which, when the program is executed by a computer, cause the computer to carry out the method described herein. The advantages achieved by the method described herein are also achieved by the computer-readable storage medium in a corresponding manner.

[0071] According to another aspect, some embodiments of the disclosure also relate to a vehicle having an electronic steering system. The advantages achieved by the method described herein are also achieved by the vehicle in a corresponding manner.

[0072] For the purposes of the present disclosure, a vehicle can in particular include a land vehicle, including but not limited to off-road and on-road vehicles such as passenger cars, buses, trucks and other utility vehicles. The vehicle can be manned or unmanned. The vehicle can be at least partially electrically driven, having an internal combustion engine and / or an electric motor serving as a drive.

[0073] All features explained with regard to the individual aspects can be combined individually or with other aspects (sub-) combinations. BRIEF DESCRIPTION OF DRAWINGS

[0074] The present disclosure and other advantageous embodiments and refinements thereof are described and explained in more detail in connection with examples shown in the accompanying drawings. In the drawings:

[0075] - Figure 1 shows a simplified schematic of a vehicle with an electronic steering system according to an embodiment,

[0076] - Figure 2 shows a simplified schematic of a method for operating a vehicle with an electronic steering system, and

[0077] - Figure 3 shows a simplified schematic of a wheel angle curve in the context of the method. DETAILED DESCRIPTION

[0078] The following detailed description describes and illustrates embodiments of the disclosed subject matter, and is not intended to limit the scope of the disclosed subject matter. Each embodiment described in this disclosure is an example or is merely for illustration, and should not be construed as preferred or superior over other embodiments. Illustrative examples contained herein should not be construed as limiting the scope of the claimed subject matter to the exact process, composition, and specifications described. Different variations of the described embodiments are readily discernible by one skilled in the art and the general principles defined herein can be applied to other embodiments and applications without departing from the spirit and scope of the described embodiments. Thus, the described embodiments are not limited to the embodiments shown, but are to be accorded the widest scope consistent with the principles and features disclosed herein.

[0079] All features disclosed in the specification, the claims, and the accompanying drawings, which are illustrative only, can be combined with one another in any combination, including with the features of the preferred embodiments, unless otherwise explicitly excluded by the context. The disclosure is not limited to the embodiments disclosed.

[0080] For the purposes of the present disclosure, the expression “at least one of A, B, and C” means, for example, (A), (B), (C), (A and B), (A and C), (B and C), or (A, B, and C), including any other possible combination of the items listed, if more than three items are listed. In other words, the expression “at least one of A and B” generally means “A and / or B”, i.e. either “A” alone, “B” alone, or “A and B”.

[0081] Figure 1 shows a simplified schematic of a vehicle 10 with an electronic steering system 12 according to an embodiment.

[0082] The vehicle 10 further comprises steerable vehicle wheels 14. The steerable vehicle wheels 14 are coupled to a common steering rack 16. The common steering rack 16 can be moved from a reference position, e.g. a zero position, which causes a steering motion of the steerable vehicle wheels 14. Thus, the steerable vehicle wheels 14 can be deflected, e.g. from a straight ahead direction of the vehicle 10, so that the vehicle 10 performs a turning maneuver. Thus, the steerable vehicle wheels 14 have different wheel angles in case of a deflection of the steering rack 16, for example.

[0083] Even though here only a front wheel deflection is shown, the vehicle 10 can of course have a rear wheel deflection as an alternative or in addition.

[0084] In order to move the steering rack 16, the electronic steering system 12 has a wheel actuator 18. In the present case, the wheel actuator 18 is coupled to the steering rack 16. Alternatively, the wheel actuator 18 can also be coupled to the steerable vehicle wheels 14 in a different way in order to control their alignment (wheel angle).

[0085] According to the present embodiment, the wheel actuator 18 has an electric motor 20. The electric motor 20 has at least one winding set 22, which comprises a set of windings. Each winding set 22 is configured such that when a power supply signal, such as a phase voltage, is applied, a phase current is generated in the underlying winding, which can be used to drive a rotor of the electric motor 20. The rotor can then be coupled to the steering rack 16 and thus enable a movement of the steering rack 16.

[0086] Generally, the electric motor 20 can have more than one winding set 22.

[0087] Generally, each winding set 22 is three-phase, so that the electric motor 20 in the present case also has a three-phase design. However, the electric motor 20 can also have more winding sets 22 and thus be six-phase or nine-phase, or generally 3n-phase, where n is greater than or equal to 1.

[0088] The wheel actuator 18 further comprises at least one wheel sensor 24. Generally, also a plurality of wheel sensors 24 can be provided. The wheel sensor 24 is configured to detect a position and / or a motion of the steerable vehicle wheel 14 or of a component coupled thereto, here the steering rack 16. Detecting the position of the steering rack 16 allows to determine the wheel angle of the steerable vehicle wheel 14. Thus, the alignment of the steerable vehicle wheel 14 can be determined.

[0089] Even though the wheel sensor 24 is here formed as part of the wheel actuator 18, the wheel sensor 24 can optionally be arranged separately from the wheel actuator 18 and still be configured to detect a position and / or a motion of a steerable vehicle wheel 14 of the vehicle or of a component coupled thereto. For example, the wheel sensor 24 can be coupled to the steering rack 16 separately from the wheel actuator 18.

[0090] The electronic steering system 12 of the vehicle 10 also has a steering wheel 30. Using the steering wheel 30, a driver of the vehicle 10 can activate a steering specification of the vehicle 10 to steer the vehicle 10 in a desired direction.

[0091] A steering wheel actuator 32 of the electronic steering system 12 is coupled to the steering wheel 30. The steering wheel actuator 32 has a further electric motor 34. The electric motor 34 of the steering wheel actuator 32 also comprises a winding set 22. In general, the electric motor 34 can also have a plurality of winding sets 22. The winding set 22 of the electric motor 34 of the steering wheel actuator 32 is configured in a corresponding manner to the winding set 22 of the electric motor 20 of the wheel actuator 18. This means that the winding set 22 of the electric motor 34 is configured to drive a rotor of the electric motor 34. As a result, the steering wheel 30 of the vehicle 10 can be acted upon by a torque from the electric motor 34, which represents a feedback torque of the driver to convey a feeling of lateral guidance of the vehicle 10 to the driver.

[0092] In the present case, the electric motor 34 of the steering wheel actuator 32 has a winding set 22 and is thus three-phase, but it can also be designed as 3n-phase, with n being greater than or equal to 1.

[0093] The electronic steering system 12 also has a steering wheel sensor 36, which is part of the steering wheel actuator 32. In general, more steering wheel sensors 36 can also be provided. The steering wheel sensor 36 is configured to detect a steering specification of the driver by means of a steering wheel angle of the steering wheel 30 or a component coupled thereto, for example a steering column, relative to a reference position.

[0094] In an alternative, the steering wheel sensor 36 can also be separate from the steering wheel actuator 32 and still be configured to detect a position and / or a movement of the steering wheel or a component coupled thereto of the vehicle 10.

[0095] In the present case, the electronic steering system 12 of the vehicle 10 comprises a control device 42. The control device 42 has at least one data processing device 44 and is coupled to the wheel actuator 18, the wheel sensor 24, the steering wheel actuator 32 and the steering wheel sensor 36.

[0096] In general, the electronic steering system 12 can also have separate control devices, which in each case are assigned to the wheel actuator 18 and the steering wheel actuator 32, respectively. In the present case, however, the control functions are combined in a single control device 42.

[0097] Furthermore, the electronic steering system 12 has at least one data store 46, which is coupled to the control device 42. The data store 46 is configured such that suitable parameters of the electronic steering system 12 can be stored therein.

[0098] The control device 42 serves as a link between the wheel actuator 18 and the steering wheel actuator 32 in order to, on the one hand, implement a change in the wheel angle of the steerable vehicle wheels 14 of the vehicle 10 in accordance with a steering specification by the driver via the steering wheel 30 and, on the other hand, to ensure a torque feedback of the driver of the vehicle 10 on the steering wheel 30 based on vehicle and / or actuator information.

[0099] In the present case, the control device 42 is specifically designed to detect a false automatic steering of the steering wheel 30 caused by the steering wheel actuator 32. To this end, the control device 42 can evaluate measurement data or information of the steering wheel actuator, e.g. based on current measurement values, from the steering wheel sensor 36, which is configured to detect a steering wheel rotational speed and / or a steering wheel angle of the steering wheel 30. In this regard, the control device 42 is configured to detect a false application of a feedback torque by the steering wheel 30 with the help of the steering wheel actuator 32.

[0100] Furthermore, the control device 42 is configured to store parameters of the electronic steering system 12 in a data storage 46.

[0101] Figure 2 A simplified schematic of a method 50 for operating a vehicle 10 with an electronic steering system 12 is shown. Optional steps are shown in dashed lines.

[0102] In an optional step S1, the control device 42 of the electronic steering system 12 detects a false automatic steering of the steering wheel actuator 32. This can be based on measurement values detected by the steering wheel sensor 36 and transmitted to the control device 42, for example.

[0103] In the following step S2, the control device 42 estimates a steering wheel angle change of the steering wheel 30 based on the false automatic steering of the steering wheel actuator 32. The steering wheel angle change can finally be used as an output variable to estimate the influence of the false automatic steering.

[0104] Subsequently, in step S3, the control device 42 triggers at least one compensation measure so that at least the wheel angle change actually caused by the estimated steering wheel angle change - the false automatic steering - is reduced. The compensation measure can be configured in different ways and can also comprise a combination of individual measures. This means that in the normal operating state of the electronic steering system 12, the control of the wheel actuator 18 is modified with respect to the original control. As a result, the steering wheel angle change of the steering wheel 30 based on the false automatic steering is not propagated as it would be the case in the actual wheel angle change thus defined. Thus, the influence of the false automatic steering of the steering wheel actuator 32 can advantageously be mitigated. Based on the compensation measure, the vehicle lateral guidance can be adapted to the required trajectory (without false automatic steering) more quickly than before.

[0105] Thus, the method 50 comprises an optional step S17 in which, taking into account the compensation measure, an actuation signal is outputted, preferably by the control device 42, to the wheel actuator 18 so that at least partially compensates for the wheel angle variation based on the steering wheel angle variation estimated with respect to the erroneous automatic steering. In this respect, the actuation signal adjusted with respect to the unmodified profile is outputted to the wheel actuator 18 so that the lateral guidance of the vehicle is advantageously less deviated from the steering specification of the driver (without erroneous automatic steering).

[0106] In an optional step S4, the control device 42 estimates a wheel angle variation of the steerable vehicle wheel 14 of the vehicle 10, which is in fact caused by the estimated steering wheel angle variation of the erroneous automatic steering. In this case, the control device 42 takes into account the original (unmodified) transfer function, which describes the correlation of the wheel angle variation of the steerable vehicle wheel 14 with the steering specification variation of the steering wheel 30 by the driver of the vehicle 10. As a result, the information base of the compensation measure in step S3 can be enlarged so that the compensation measure can be tailored to the specific situation.

[0107] Optionally, in order to determine the wheel angle variation, the control device 42 can express the steering wheel angle variation based on the erroneous automatic steering in terms of the transfer function. The transfer function usually has a non-linear curve shape. Thus, for each vehicle application, different transfer functions are considered, for example in the form of characteristic curves or characteristic maps, which describe the correlation between the wheel angle and the steering wheel angle for the respective vehicle application depending on the operating point. Thus, “express in terms of” here means that the transfer function applicable for the specific operating profile (operating point) is taken into account in order to determine the wheel angle variation based on the steering wheel angle variation caused by the erroneous automatic steering. Thus, in mathematical terms, “express in terms of” can mean, for example, division or multiplication, depending on the definition of the transfer function. Thus, the influence of the erroneous automatic steering of the steering wheel actuator 32 is more precisely normalized (adjusted) to the respective electronic steering system 12, the vehicle 10 and the respective vehicle application. Since the transfer function describes the specific correlation of the respective electronic steering system 12, the influence of the steering wheel angle variation caused by the erroneous automatic steering of the steering wheel actuator 32 on the resulting wheel angle variation is related to the respective electronic steering system 12, the vehicle 10 and / or the respective vehicle application. In other words, the specific characteristics of the underlying electronic steering system 12, the vehicle 10 and the vehicle application in terms of the effective coupling between the steering wheel 30 and the steerable vehicle wheel 14 can be taken into account.

[0108] In step S2 and / or S3, the control device 42 can take into account a diagnostic time interval of the control device 42 when estimating the steering wheel angle change based on the error and / or when determining the necessary compensation measures (steps S5 to S9).

[0109] For example, the diagnostic time interval can be predefined or variable (step S5). If the diagnostic time interval is predefined, the method 50 is particularly compact. The diagnostic time interval describes the time interval required by the control device 42 to determine and trigger (diagnostic end time) appropriate measures upon detection of the error automatic steering (diagnostic start time).

[0110] The variable diagnostic time interval can be determined based on single or multiple optional method steps (steps S6 to S9).

[0111] According to step S6, to determine the diagnostic time interval, the control device 42 can take into account the fact that a steering wheel speed difference of the steering wheel 30 occurs between the diagnostic start time and the diagnostic end time of the diagnostic time interval. In this case, the steering wheel speed difference is determined by the control device 42 based on the torque actually applied to the steering wheel 30 or the maximum torque that can be applied to the steering wheel 30 by the steering wheel actuator 32. The maximum torque that can be applied by the steering wheel actuator 32 is usually predetermined by the device parameters of the steering wheel actuator 32. For example, the actually applied torque can be determined by sensors that detect the motor speed and / or the phase voltage, etc. Knowing the steering wheel speed at the diagnostic start time or the diagnostic end time, the duration of the diagnostic time interval can be determined. For example, the steering wheel speed can be detected using the steering wheel sensor 36.

[0112] In optional step S7, the control device 42 can determine the steering wheel speed difference using a non-linear function.

[0113] In optional step S8, the variable diagnostic time interval can be determined by the control device 42 by assuming a constant steering wheel speed at the diagnostic start time, in particular, for example, a steering wheel speed of 0 degrees / second. In other words, according to this approximation, it is assumed that the steering wheel 30 is in a rest position at the diagnostic start time. Thus, for example, based on the torque actually applied to the steering wheel 30 by the steering wheel actuator 32 or the maximum torque that can be applied, for example, by taking into account the steering wheel speed at the diagnostic end time, the length of the diagnostic time interval can be estimated.

[0114] According to optional step S9, the control device 42 can be coupled to a memory device 46. Memory device 46 can continuously store stored values ​​for the steering wheel angle and / or steering wheel speed and / or torque applied to the steering wheel 30 by the steering wheel actuator 32. Consequently, the control device 42 can use the stored values ​​in memory device 46 to determine a diagnostic time interval. For example, the stored value of the steering wheel speed can be considered at a time corresponding to the start time of the diagnostics. This stored value can be determined, for example, based on a measurement value of the steering wheel sensor 36 that detects the steering wheel angle and stored in memory device 46.

[0115] Alternatively, the memory device 46 may also store parameters of the electric motor 34 correspondingly determined by the control device 42 , which parameters may also be used to determine the steering wheel angle and / or the steering wheel speed at the start of the diagnosis.

[0116] In step S9, the control device 42 can, for example, retrieve the appropriate entry corresponding to the diagnosis start time from the memory device 46. Since the steering wheel angle and / or steering wheel speed and / or torque at the diagnosis start time are known from this point on, the corresponding quantities can be determined relative to the diagnosis end time. Similarly, measured values, such as those of the steering wheel sensor 36, can be used. Based on the steering wheel speed difference, the actual torque applied to the steering wheel 30 by the electric motor 34 can be determined. Thus, the change in the steering wheel angle caused by the incorrect automatic steering of the steering wheel actuator 32 can be determined.

[0117] In optional step S9, the control device 42 can determine the diagnosis start time by searching the stored values ​​in the memory device 46 for any significant changes (large gradients) in the detected steering wheel angle and / or the detected steering wheel speed and / or the torque output by the electric motor. This is derived from the fact that the erroneous automatic steering causes the steering wheel 30 to spontaneously and suddenly move. This movement of the steering wheel 30 is based on the fact that the electric motor 34 of the steering wheel actuator 32 outputs a sudden torque to the steering wheel 30, which causes a sudden change in the steering wheel angle. Therefore, the diagnosis start time can be determined based on the identification of the corresponding large gradient values.

[0118] The different steps S6 to S9 can also be used for a mutual plausibility check by the control device 42 .

[0119] Thus, when estimating the steering wheel angle change caused by an erroneous automatic steering, a diagnostic time interval is taken into account, which the control device 42 uses to determine and trigger (diagnosis end time) appropriate measures upon detection of an erroneous automatic steering (diagnosis start time). Thus, parameters of the control device 42, such as its computing power, and (optionally) characteristics of the steering wheel actuator 32, such as the torque generated, can be taken into account.

[0120] The optional steps S5 to S9 allow to improve the accuracy of the estimated steering wheel angle change. As a result, the extent of the wheel angle change caused by the erroneous automatic steering of the steering wheel actuator 32 can be determined more precisely.

[0121] Optionally, the method 50 can be further developed by a step S10, in which the control device 42 modifies the transfer function as a compensatory measure upon detection of the erroneous automatic steering of the steering wheel actuator 32. The modified transfer function causes a more indirect control of the wheel angle change, i.e. of the target value of the vehicle lateral guidance, compared to the unmodified transfer function, resulting in a response of the vehicle via the steering wheel 30 to the steering specification of the driver. This means that for the relationship between the wheel angle change and the steering wheel angle change, no longer the transfer function actually correctly describing (without error) the electronic steering system 12 is used, but a value specifically adapted to it. For example, the wheel angle change amplitude based on the modified transfer function can be smaller than the unmodified transfer function for the same steering specification.

[0122] Optionally, as part of the compensatory measure, the offset angle caused by the change of the transfer function from the original transfer function to the modified transfer function by the control device 42 according to step S11 is reduced at least partially based on the modified transfer function, e.g. within the offset time interval. This can avoid sudden changes of the vehicle lateral guidance system.

[0123] The compensatory measure can also optionally be implemented in the form of a step S12, in which the control device 42 applies a filtering measure to the steering wheel input of the steering wheel 30. Thus, the measurement signal from the driver steering wheel input can be directly influenced, which also results in a change of the vehicle lateral guidance behavior.

[0124] For example, the filtering measure according to the optional step S13 can be provided by the control device 42 by a low-pass filtering. Thus, the influence of the steering wheel position of the steering wheel 30 can be reduced in amplitude, ensuring a smooth influence of the driver steering wheel input on the vehicle lateral guidance. This also results in a more indirect influence of the steering wheel angle change on the corresponding change of the wheel angle.

[0125] The method 50 can also comprise a compensation measure as specified in optional step S14. Thus, when providing the driver with a torque feedback on the steering wheel 30, which is implemented by the steering wheel actuator 32, the control device 42 takes into account an additional pulse reverse torque applied to the steering wheel 30. By "pulse" is meant that a high, preferably maximum, reverse torque is applied, for example depending on the performance of the steering wheel actuator 32. For this purpose, a corresponding characteristic curve can be selected. The reverse torque is opposite to the torque caused by the false automatic steering of the steering wheel angle. Reducing the steering wheel speed reduces the size of the false steering angle and thus the size of the false wheel angle and thus in turn the severity of the false vehicle response. Furthermore, this ensures that the potential overreaction of the driver is lower than without the reverse torque. Normally, the torque feedback gives the driver a feeling of steering the vehicle 10 laterally. However, the false automatic steering of the steering wheel actuator 32 can cause a high torque feedback, which the driver of the vehicle 10 wants to correct, but this often leads to an overcorrection of the driver (see, for example, time t4 in Fig. 1). When controlling the steering wheel actuator 32 after the false automatic steering, the pulse reverse torque taken into account by the control device 42 will now provide a force on the steering wheel to the driver in the opposite direction to the false direction, so that the size of the necessary correction made by the driver will be smaller and thus the overcorrection of the driver can be reduced or completely prevented. Figure 3 As a further development, the compensation measure according to optional step S15 can also provide that the feedback torque is increased by the control device 42 compared to the feedback torque in the normal state. Here, a characteristic curve of the feedback torque is used, which has a greater amplitude range than the normal curve, but has a smaller amplitude range than the characteristic curve used in the context of the pulse reverse torque. Thus, after a false automatic steering action has been detected, the feedback torque applied to the steering wheel 30 by the steering wheel actuator 32 is higher than the feedback torque provided to the driver before the false automatic steering action. By increasing the feedback torque, the effect of the wheel angle change is reduced. In this case, for example, the wheel angle can be detected by the wheel sensor 24 and transmitted to the control device 42. As a result, the driver of the vehicle 10 reacts to the reduced steering specification, so that the effects of the false automatic steering can be corrected more easily compared to without the compensation measure.

[0126] As a further development, the compensation measure according to optional step S15 can also provide that the feedback torque is increased by the control device 42 compared to the feedback torque in the normal state. Here, a characteristic curve of the feedback torque is used, which has a greater amplitude range than the normal curve, but has a smaller amplitude range than the characteristic curve used in the context of the pulse reverse torque. Thus, after a false automatic steering action has been detected, the feedback torque applied to the steering wheel 30 by the steering wheel actuator 32 is higher than the feedback torque provided to the driver before the false automatic steering action. By increasing the feedback torque, the effect of the wheel angle change is reduced. In this case, for example, the wheel angle can be detected by the wheel sensor 24 and transmitted to the control device 42. As a result, the driver of the vehicle 10 reacts to the reduced steering specification, so that the effects of the false automatic steering can be corrected more easily compared to without the compensation measure.

[0127] Alternatively or cumulatively, according to optional step S16, additional damping torque may also be considered. The damping torque may be based on, for example, mechanical and / or electronically controlled damping. For example, this may be influenced by mechanical friction or resistance, such as by short-circuiting the windings of the electric motor and / or by connecting an additional resistor. Furthermore, a modified control program may be used to control the steering wheel actuator, which produces higher damping. The damping torque is specifically triggered by the control device 42 and optionally also controlled. The damping torque reduces the effect of erroneous automatic steering, causing the steering wheel actuator 32 to generate a corresponding torque at the steering wheel 30 at a slower rate. This ensures that the driver has an extended period of time to offset the torque feedback. As a result, the change in torque feedback at the steering wheel 30 is less abrupt, allowing the driver of the vehicle 10 to countersteer more appropriately, resulting in reduced driver overcorrection. Considering the damping torque also ensures that redundancy is provided to the driver in the form of passive torque feedback, for example in situations where active feedback torque cannot be actively applied because the active feedback channel is no longer available.

[0128] In view of this, Figure 3 A simplified schematic diagram 52 of a wheel angle curve in the context of method 50 is shown. The y-axis shows the wheel angle of the steerable vehicle wheel 14 over time on the x-axis. Reference numeral 54 denotes the curve of the wheel angle without adjusting the translation function. Conversely, reference numeral 56 denotes the curve of the wheel angle of the steerable vehicle wheel 14 when the control device 42 applies the modified translation function at time t1.

[0129] Time t0 indicates the onset of the erroneous automatic steering action of the steering wheel actuator 32. The control unit 42 requires a certain time interval to detect the erroneous automatic steering action in order to determine and trigger appropriate measures. Therefore, time t0 also designates the diagnostic start time. At time t1, the control unit 42 triggers one or more corresponding compensatory measures. Consequently, time t1 also marks the diagnostic end time. Therefore, the time interval between time points t0 and t1 is the diagnostic interval.

[0130] At time t1, control device 42 modifies the translation function in such a way that it now causes only an indirect response of the wheel angle change to the steering wheel angle change. As a result, for curve 56 (with the modified translation function), the magnitude of the wheel angle change based on the steering wheel angle change is smaller than for curve 54 (with the unmodified translation function).

[0131] At time t2, the wheel angle no longer changes, but remains constant, due to the reaction torque of the driver of the vehicle 10. Since the curve 56 of the wheel angle (with the modified translation function) has a lower amplitude than the unmodified curve 54, the vehicle 10 will follow the original trajectory as intended by the driver more closely and only reduce the deviation (distance) from the original trajectory.

[0132] At time t3, the driver of the vehicle 10 starts to correct the path of the vehicle 10 by countersteering in order to return to the desired trajectory. Also in this phase, the amplitude of the wheel angle change based on the countersteering movement (due to the modified translation function) is also smaller than in the case of the curve 54 with the original translation function. This leads to a reduced overcorrection of the influence of the false automatic steering by the driver of the vehicle 10 (time t4).

[0133] At time t5, the countersteering of the driver of the vehicle 10 brings the curve 56 of the wheel angle with the modified translation function again into alignment with the desired trajectory.

[0134] Different configurations of the compensation measures can reduce (avoid) abrupt changes in the lateral guidance of the vehicle and sudden changes in the wheel angle.

[0135] All embodiments of the method 50 according to steps S4 to S17 lead to a determination and triggering of appropriate compensation measures in the control device 42 in order to prolong the time period granted to the driver to counteract an unintentional steering movement and they lead to an immediate reduction of the influence of the false automatic steering of the steering wheel actuator 32. Thus, a method 50 is provided which increases the comfort of the driver and allows a faster reduction of the influence of the false automatic steering than previous methods.

[0136] The specific embodiments disclosed herein use circuitry (e.g., one or more circuits) to implement the standards, protocols, methods, or techniques disclosed herein, to functionally couple two or more components, to generate information, to process information, to analyze information, to generate signals, to encode / decode signals, to convert signals, to transmit and / or receive signals, to control other devices, and / or the like. Any type of circuitry can be used.

[0137] In one embodiment, a circuit, such as a control device, includes at least one or more data processing devices, e.g., a processor (e.g., a microprocessor), a central processing unit (CPU), a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), a system-on-chip (SoC), or similar device, or any combination thereof, and can include discrete digital or analog circuitry or electronics, or combinations thereof. In one embodiment, the circuit includes a hardware circuit implementation (e.g., an implementation in analog circuitry, an implementation in digital circuitry, etc., and combinations thereof).

[0138] In one embodiment, the circuitry includes a combination of circuitry and computer program products with software or firmware instructions stored on one or more computer-readable memories and interacting in one or more ways to cause an apparatus to perform one or more of the protocols, methods, or techniques described herein. In one embodiment, the circuitry includes circuitry that requires software, firmware, etc. to operate, such as a microprocessor or components of a microprocessor. In one embodiment, the circuitry includes one or more processors or components thereof and associated software, firmware, hardware, etc.

[0139] The present disclosure can involve quantities and numbers. Unless explicitly stated, these quantities and numbers should not be considered limiting but as examples of possible quantities or numbers in relation to the present disclosure. In this context, the term “plurality” can also be used in the present disclosure to refer to a quantity or number. In this context, “plurality” shall mean any number greater than one, such as two, three, four, five, etc. The terms “roughly,” “approximately,” “near,” and the like mean ±5% of the specified value.

[0140] While the present disclosure has been presented and described with respect to one or more embodiments, those skilled in the art will appreciate that equivalent alterations and modifications will occur to them upon reading and understanding the specification and the annexed drawings.

Claims

1. A method (50) for operating a vehicle (10) having an electronic steering system (12), the electronic steering system comprising at least a steering wheel actuator (32), a steering wheel (30) coupled to the steering wheel actuator (32), a wheel actuator (18), a steerable vehicle wheel (14) coupled to the wheel actuator (18), and a control device (42) coupled at least to the steering wheel actuator (32) and to the wheel actuator (18), wherein the control device (42) is configured to control the wheel actuator (18) in such a way that the steerable vehicle wheel (14) assumes a wheel angle defined by a detected steering wheel angle of the steering wheel (30) in accordance with a translation function, and the control device (42) is configured to detect an erroneous self-steering of the steering wheel actuator (32), wherein the translation function describes a dependency of the wheel angle on the detected steering wheel angle, and wherein after detecting the erroneous self-steering, the method (50) comprises at least the following steps: - estimating, by the control device (42), a steering wheel angle change based on the erroneous self-steering of the steering wheel actuator (32), and - triggering, by the control device (42), at least one compensation measure so that the wheel angle change based on the estimated steering wheel angle change is at least reduced.

2. The method (50) according to claim 1, characterized in that The compensation measure comprises determining the wheel angle change based at least on the steering wheel angle change estimated by the control device (42) and considering an original translation function.

3. The method (50) according to claim 2, characterized by, For determining the wheel angle change, the control device (42) represents the steering wheel angle change based on the erroneous self-steering with the translation function or a respective operating point of the translation function.

4. The method (50) according to any of the preceding claims, characterized by, When estimating the steering wheel angle change based on the erroneous self-steering, the control device (42) considers a diagnostic time interval of the control device (42), wherein the diagnostic time interval is: - predetermined and constant, or - determined based on the fact that a steering wheel rotational speed of the steering wheel at a diagnostic start time is equal to 0 degrees per second, or - determined based on the fact that a continuous average steering wheel rotational speed before the diagnostic start time is considered, or - determined based on the fact that a steering wheel rotational speed difference of the steering wheel (30) between a diagnostic start time and a diagnostic end time of the diagnostic time interval is considered, wherein the steering wheel rotational speed difference is determined by the control device (42): i. based on a non-linear function, or ii. based on a maximum torque that can be applied to the steering wheel (30) by the steering wheel actuator (32), or - determined based on a memory device (46) coupled to the control device (42), wherein the memory device (46) comprises continuously stored values of the detected steering wheel angle and / or of a motor torque of the steering wheel actuator.

5. The method (50) according to any of the preceding claims, characterized by, The compensation measure comprises at least one variation in the translation function such that the estimated steering wheel angle variation based on the modified translation function only causes a reduced change in the wheel angle magnitude compared to the unmodified translation function.

6. The method (50) according to claim 5, characterized by As part of the compensation measure, the offset angle of the wheel angle caused by the modified translation function is reduced based at least on the modified translation function.

7. The method (50) according to any of the preceding claims, characterized by, The compensation measure comprises at least one filtering measure on the steering wheel input of the steering wheel (30).

8. The method (50) according to claim 7, characterized by The filtering measure comprises a low-pass filtering of the detected steering wheel angle, thereby ensuring a smoothing of the influence of the detected steering wheel angle on the vehicle lateral guidance.

9. The method (50) according to any of the preceding claims, characterized by, The compensation measure at least comprises applying an additional counter torque to the steering wheel (30) or a component coupled thereto, wherein the counter torque is applied opposite to the torque of the steering wheel angle variation caused by the erroneous automatic steering.

10. The method (50) according to any of the preceding claims, characterized by, The compensation measure at least comprises the control device (42) controlling the steering wheel actuator (32) in such a way that the feedback torque applied by the steering wheel actuator (32) to the steering wheel (30) after the erroneous automatic steering is detected is higher than the feedback torque available to the driver before the erroneous automatic steering.

11. The method (50) according to any of the preceding claims, characterized by, The compensation measure at least comprises the control device (42) controlling the steering wheel actuator (32) in such a way that an additional damping torque is considered when providing feedback torque to the steering wheel (30).

12. The method (50) according to any one of the preceding claims, characterized by, The method (50) comprises the following steps: - outputting, by the control device, an actuation signal to the wheel actuator in view of the compensation measure, thereby at least reducing the wheel angle variation based on the estimated steering wheel angle variation with respect to the erroneous automatic steering.

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