阅读说明：本技术 用于分析和/或至少部分补偿方向盘旋转振动的方法 (Method for analyzing and/or at least partially compensating for steering wheel rotational vibrations ) 是由 S.阿贝勒 T.赛博尔德 于 2018-04-03 设计创作，主要内容包括：本发明涉及一种特别是在车辆(10、12)中的转向装置运行期间用于分析和/或至少部分地补偿方向盘旋转振动的方法,其中,检测至少一个检测信号(12)并且从所述检测信号(12)中提取至少一个与方向盘旋转振动相关的干扰特征参量(14)。在此规定,在监测时间间隔期间,监测所述干扰特征参量(14)的时间变化和与当前的车轮转速特征参量相关的车轮频率(16)的时间变化,并且为了分析和/或至少部分地补偿所述方向盘旋转振动而将所述干扰特征参量(14)的时间变化和与当前的车轮转速特征参量相关的车轮频率(16)的时间变化结合成一个共同的评估数据组(18、20)。(The invention relates to a method for evaluating and/or at least partially compensating for steering wheel rotational vibrations, in particular during operation of a steering system in a vehicle (10, 12), wherein at least one detection signal (12) is detected and at least one disturbance variable (14) associated with the steering wheel rotational vibrations is extracted from the detection signal (12). During a monitoring time interval, the time variation of the disturbance variable (14) and the time variation of the wheel frequency (16) associated with the current wheel speed variable are monitored, and the time variation of the disturbance variable (14) and the time variation of the wheel frequency (16) associated with the current wheel speed variable are combined into a common evaluation data set (18, 20) for evaluating and/or at least partially compensating the steering wheel rotational vibration.)

1. Method for evaluating and/or at least partially compensating steering wheel rotational vibrations, in particular during operation of a steering system in a vehicle (10, 11), wherein at least one detection signal (12) is detected and at least one disturbance variable (14) related to steering wheel rotational vibrations is extracted from the detection signal (12), characterized in that during a monitoring time interval, a temporal change of the disturbance variable (14) and a temporal change of a wheel frequency (16) related to a current wheel rotational speed variable are monitored and, in order to evaluate and/or at least partially compensate for the steering wheel rotational vibrations, the temporal changes of the disturbance variable (14) and the temporal changes of the wheel frequency (16) related to the current wheel rotational speed variable are combined into a common evaluation data set (18, 18), 20).

2. The method according to claim 1, characterized in that the evaluation data set (18, 20) is used to establish a heat map and the heat map is evaluated at least for analyzing steering wheel rotation vibrations.

3. Method according to claim 1 or 2, characterized in that the time rate of change of the disturbance variable (14) and/or of the wheel frequency (16) is detected in the evaluation data set (18, 20) and the time rate of change of the disturbance variable (14) and/or of the wheel frequency (16) is taken into account at least for evaluating steering wheel rotational vibrations.

4. The method according to one of the preceding claims, characterized in that at least one state characteristic quantity (22) of an activation unit (24) for activating and/or deactivating the compensation of the steering wheel rotational vibrations is determined as a function of operating parameters of the vehicle (10, 12), in particular of a steering device, and is taken into account at least for the analysis of the steering wheel rotational vibrations.

5. Method according to one of the preceding claims, characterized in that the evaluation data set (18, 20) is read and/or wirelessly transmitted to an external evaluation unit via a communication interface at least for the purpose of analyzing steering wheel rotational vibrations.

6. Method according to one of the preceding claims, characterized in that at least one prompting notification is generated if a deviation from normal behavior is detected when analyzing the evaluation data set (18, 20).

7. Method according to one of the preceding claims, characterized in that, in order to at least partially compensate steering wheel rotational vibrations, a transfer function for generating a compensation signal (26) is adapted at least using the evaluation data set (18, 20).

8. Method according to claim 7, characterized in that for matching the transfer function a learning algorithm is used which is set up for optimizing at least a partial compensation for the steering wheel rotational vibrations at least on the basis of the evaluation data set (18, 20).

9. Method according to one of the preceding claims, characterized in that for the analysis and/or at least partial compensation of the steering wheel rotational vibrations, at least one further evaluation data set (18, 20) is acquired, in particular by a further vehicle (11), and combined with the evaluation data set (18, 20).

10. Steering device having a detection unit (28) which is provided for detecting at least one detection signal (12) and having a calculation unit (30) which is provided for carrying out the method according to one of claims 1 to 9.

11. System (32) comprising a plurality of steering devices according to claim 10, wherein the evaluation data sets (18, 20) of the steering devices are combined with one another in order to evaluate and/or at least partially compensate for steering wheel rotational vibrations.

12. Controller (34) of a steering device, having a computing unit (30) for performing the method according to any one of claims 1 to 9.

Technical Field

The invention is based on a method for analyzing and/or at least partially compensating for steering wheel rotational vibrations according to the preamble of claim 1.

Furthermore, the invention relates to a steering device according to claim 10, a system according to claim 11 and a control according to claim 12.

Background

Methods for analyzing and/or compensating for steering wheel rotational vibrations are known from the prior art.

In this respect, it is known, for example, to use a transfer function for compensating steering wheel rotational vibrations, which transfer function calculates an effective reaction torque on the basis of the torque signal and supplies this reaction torque to an electric motor of the steering system. In this case, the transfer function is usually determined iteratively with the aid of a single vehicle of a specific vehicle variant (fahrzeugvariate) and stored in the control unit during the manufacture of the vehicle. However, the characteristics of the transfer function (Verhalten) are strongly spread over the range of vehicles of a vehicle variant due to manufacturing-induced tolerances and/or aging phenomena, so that it is not clear how well the transfer function works in one vehicle or in other vehicles of the same vehicle variant. This results in that the optimization of the transfer function can only be carried out after a time-consuming coordination with the client. However, based on the measurement data directly from the vehicle, the function can be optimized better and faster.

Furthermore, for example, DE 102009028448 a1 discloses a method for detecting rotational vibrations of a steering wheel, wherein a rotor position or a rotor speed is detected and a dominant disturbance frequency is detected from the detected rotor position or the detected rotor speed. The interference frequency can then be used together with the current vibration form (Schwingungsform) to detect and compensate for steering wheel rotational vibrations. However, no evaluation and/or monitoring of the disturbance frequency and/or vibration pattern takes place here, so that the effectiveness of the compensation is only representative of the respective vehicle and is only perceptible subjectively by the driver, but cannot be transmitted to other vehicles.

Disclosure of Invention

The object of the invention is, in particular, to provide an advantageously flexible method with improved properties with regard to the properties analysis and/or compensation. This object is achieved by the features of the characterizing part of claim 1 and the features of claims 10, 11 and 12, while advantageous embodiments and refinements of the invention are apparent from the dependent claims.

The invention relates to a method for evaluating and/or at least partially compensating for steering wheel rotational vibrations, in particular during operation of a steering device in a vehicle, wherein at least one detection signal is detected, in particular by means of a detection unit, and at least one disturbance variable associated with the steering wheel rotational vibrations is extracted from the detection signal.

It is proposed that the time variation of the disturbance variable and the time variation of the wheel frequency associated with the current wheel speed variable are monitored during a, in particular the entire, monitoring time interval and combined into a common evaluation data set for evaluating and/or at least partially compensating for the steering wheel rotational vibrations. The wheel frequency is advantageously determined from a current wheel speed characteristic, wherein the current wheel speed characteristic can be detected, in particular, by means of a sensor unit and/or recalled from a vehicle controller or a vehicle bus system. In particular, this embodiment makes it possible to provide a particularly flexible method which allows an advantageous analysis of the properties and/or improves the effectiveness of the compensation of the rotational vibrations of the steering wheel. In addition, the effectiveness of the compensation can be demonstrated in all vehicles of a vehicle variant, whereby, in particular, outliers can be identified and/or phenomena of global coverage can be analyzed and iterative cycles and/or complaints can be reduced. Further, batch effects may be identified and/or trends may be associated with successively produced steering systems and/or vehicles. Furthermore, efficiency, in particular manufacturing efficiency, maintenance efficiency, compensation efficiency and/or cost efficiency, can advantageously be improved.

A "steering device" is to be understood in this respect to mean, in particular, at least one part, in particular a subassembly, of a steering system, in particular a vehicle and preferably a motor vehicle. The steering device may in particular also comprise the entire steering system. Furthermore, the steering device comprises in particular a detection unit which is provided for detecting at least one detection signal, in particular at least the detection signal already mentioned above, and/or a calculation unit which is provided for carrying out a method for analyzing and/or at least partially compensating for a steering wheel rotational vibration. Furthermore, the steering device may comprise further components and/or assemblies, such as, for example, at least one steering wheel, at least one steering column (in particular with at least one steering spindle), at least one steering gear, in particular an auxiliary unit operatively connected to the steering gear for generating and/or providing steering assistance, and/or a sensor unit for detecting a characteristic variable of the wheel speed. "provided" is to be understood in particular to mean specially programmed, designed and/or equipped. The expression "an object is provided for a specific function" is intended to mean, in particular, that the object fulfills and/or performs this specific function in at least one operating state and/or operating state.

A "detection unit" is to be understood to mean, in particular, a unit which is operatively connected to the computing unit and is provided for detecting the detection signal in a contact-bound and/or advantageously contactless manner. For this purpose, the detection unit comprises in particular at least one preferably electrical, acoustic, optical and/or magnetic detection element, which can advantageously be designed as a passive and/or active sensor. Furthermore, the detection unit is provided in particular for supplying the detection signal and/or a signal related to the detection signal and forwarding it, in particular wirelessly and/or advantageously by wire, to the computing unit. The detection signal can be, for example, a signal associated with the auxiliary unit and/or a signal associated with the motor of the auxiliary unit, such as, for example, the rotor position angle, the rotor speed and/or preferably the motor torque, in particular the actual motor torque. The detection signal can also be correlated and/or assigned to a wheel speed characteristic, for example. However, it is particularly preferred if the detection signal is a signal which is dependent on the steering column, in particular a pinion angle of a steering pinion of the steering gear, a steering wheel angle of the steering wheel, and/or particularly advantageously a torque signal on the steering spindle side.

Furthermore, a "computer unit" is to be understood to mean, in particular, an electronic unit having an information input, an information processing unit and an information output. Advantageously, the computing unit also has at least one processor, at least one memory, at least one input and/or output device, at least one operating program, at least one regulating program, at least one control program, at least one compensation program, at least one computing program and/or at least one evaluation program. In particular, the computing unit is at least provided for extracting at least one disturbance variable related to the steering wheel rotational oscillation from the detection signal, in particular by means of an evaluation program, monitoring a temporal change of the disturbance variable and a temporal change of the wheel frequency related to the current wheel rotational speed variable during a, in particular entire, monitoring time interval, and combining the temporal changes into a common evaluation data set for the purpose of evaluation and/or for the purpose of at least partially compensating for the steering wheel rotational oscillation. Furthermore, the computing unit is preferably provided for at least partially compensating for steering wheel rotational vibrations, in particular by means of a compensation program and a transfer function which is preferably stored in a memory of the computing unit. For this purpose, in at least one operating state, a compensation signal, in particular a compensation motor torque, is generated as a function of the detection signal and using the transfer function, said compensation signal being supplied to the auxiliary unit and in particular to the motor of the auxiliary unit in order to at least partially compensate for the steering wheel rotational vibrations. It is particularly advantageous if the steering device and preferably the calculation unit further comprise an activation unit which is provided to activate and/or deactivate the compensation of the steering wheel rotational vibrations as a function of operating parameters of the vehicle and/or the steering device, such as, for example, the current vehicle speed, the current steering angle and/or the current load of the onboard power supply system, in particular by means of a compensation program and a transfer function. Preferably, the computing unit is furthermore integrated into a control unit of the steering device.

Furthermore, a "disturbance variable" is to be understood to mean, in particular, a variable which is associated with a steering wheel rotation oscillation which is based on a vehicle disturbance and is caused, for example, by an imbalance in the brake disk ("brake jerk") and/or an imbalance in the wheel ("shim-my"). In particular, the presence, intensity, type and/or cause of the steering wheel rotational vibrations can be inferred and/or detected from at least the disturbance characteristic variable. In this case, the interference characteristic variable may be, in particular, an interference frequency and/or an interference phase. However, it is particularly preferred if the disturbance characteristic variable is a disturbance amplitude, as a result of which particularly advantageously simple evaluation can be achieved. Advantageously, the interference characteristic variable, which is designed as an interference amplitude, is observed and/or evaluated at least in the interval between 0 Nm and 0.7Nm, preferably in the interval between 0 Nm and 0.5 Nm and preferably in the interval between 0 Nm and 0.3 Nm. In this case, the interference characteristic variable embodied as the interference amplitude is detected with a step size of at most 0.1 Nm, advantageously with a step size of 0.05 Nm and particularly advantageously with a step size of 0.02 Nm. Furthermore, a "wheel rotational speed characteristic" is to be understood to mean, in particular, a characteristic which is dependent on the wheel rotational speed of the wheel. In particular, the current wheel speed can be inferred and/or determined at least from the wheel speed characteristic variable. The wheel speed characteristic variable preferably corresponds to the wheel speed of the individual wheels of the vehicle or to a preferably calculated variable which is detected by at least two wheels of the vehicle, preferably to an average value of the wheel speeds of the wheels. The wheel frequency, which can be derived in particular from the wheel speed characteristic, is preferably observed and/or evaluated at least in the interval between 5Hz and 35 Hz, and preferably between 9 Hz and 18 Hz. The wheel frequency is particularly advantageously detected here in steps of up to 1 Hz and advantageously in steps of 0.5 Hz. The term "monitoring time interval" is intended to mean, in particular, a time interval of longer duration and advantageously correlated with the service life of the steering system, the steering system and/or the vehicle, in which changes in the disturbance variable and in the wheel frequency are detected. In particular, the monitoring interval can comprise a period of several days, preferably a period of several weeks, preferably a period of several months, and particularly preferably a period of several years. Furthermore, the expression "monitoring the temporal profile of the disturbance variable and/or of the wheel frequency" is to be understood in particular to mean detecting and preferably collecting values of the disturbance variable and/or of the wheel frequency, in particular continuously and/or at regular time intervals, and/or detecting the frequency and/or the duration of the disturbance variable and/or of the wheel frequency in a defined state, in particular preferably in a predefined state.

Furthermore, it is proposed that the detection signal is preferably filtered on the basis of the wheel frequency for the purpose of extracting the disturbance variable, as a result of which the disturbance variable can be acquired and/or correlated with the wheel frequency particularly advantageously in a simple manner. The filtering is preferably carried out by means of a band pass filter (Bandpass) which is advantageously variable in frequency, the resonance frequency of which is preferably set using the wheel frequency, the wheel speed characteristic, the current wheel speed and/or the current vehicle speed.

The evaluation data set can be evaluated, for example, in the form of tables, dot diagrams, histograms and/or annular diagrams, etc., for analyzing the steering wheel rotational vibrations and/or for at least partially compensating them. Preferably, however, it is provided that the evaluation data set is used to create a heat map, and that the heat map is evaluated at least for the purpose of evaluating steering wheel rotational vibrations. In particular, this makes it possible to carry out an advantageously rapid analysis and/or evaluation of the evaluation data set. Furthermore, advantageously simple further processing of the evaluation data set can be achieved. Further, alternatively or additionally, the heat map may also be used to at least partially compensate for steering wheel rotational vibration. Furthermore, a plurality of evaluation data sets, in particular from a plurality of further vehicles, can be used to create a common heat map, by means of which vehicle-specific and/or vehicle-type-specific steering wheel rotational vibrations and/or trends can be advantageously identified.

In a further embodiment of the invention, it is provided that a time rate of change of the disturbance variable and/or of the wheel frequency is detected in the evaluation data set and is taken into account at least for evaluating the steering wheel rotational oscillation. In particular, unusual changes can be detected and/or long-term characteristics can be evaluated. The temporal rate of change advantageously corresponds to an advantageously longer, for example lasting for at least one week and/or at least one month, continuous change of the disturbance variable and/or of the wheel frequency. Preferably, the change in the disturbance variable and/or in the wheel frequency is different from a short-term and/or temporary change in the disturbance variable and/or in the wheel frequency, such as a change in the range of minutes, hours and/or days, for example, in order to exclude temporary disturbances. Alternatively or additionally, the time rate of change of the disturbance variable and/or of the wheel frequency can also be used to at least partially compensate for the steering wheel rotational vibrations.

Furthermore, it is proposed that at least one state parameter and advantageously a plurality of, in particular at least two and advantageously at least three state parameters of an activation unit, in particular of the activation unit already mentioned above, for activating and/or deactivating the compensation of the steering wheel rotational vibrations as a function of operating parameters of the vehicle, in particular of the steering device, are detected and taken into account at least for evaluating the steering wheel rotational vibrations. The effectiveness of the compensation characteristic can thus advantageously be analyzed. A "state parameter" is to be understood here to mean, in particular, a parameter which is dependent on the state of the activation unit, such as, for example, "compensation activated", "compensation deactivated" and/or "waiting", and which advantageously defines a state of the compensation of the rotational vibration of the steering wheel. In particular, the state of the activation unit can be inferred and/or determined at least from the state parameter. In particular, it is possible to deduce the frequency and/or the dwell time of the activation unit in one of the states from the state characteristic variables and/or to determine the frequency and/or the dwell time of the activation unit in one of the states. Alternatively or additionally, the state characteristic variable can also be used to at least partially compensate for steering wheel rotational vibrations.

The evaluation data set can be evaluated, for example, in the computing unit, in particular by means of an evaluation program. In a preferred embodiment of the invention, however, it is provided that, at least for the purpose of evaluating steering wheel rotational vibrations, the evaluation data set is read via a communication interface, in particular a diagnostic interface, such as, for example, an OBD2 socket, and/or a bus communication interface inside the vehicle, and/or is preferably transmitted wirelessly by means of a central communication unit ("CCU"), such as, for example, via a mobile radio connection, a WLAN connection, etc., to an external and advantageously central evaluation unit. This makes it possible in particular to provide an advantageously high computational power and to achieve an advantageously rapid evaluation. Furthermore, the evaluation data set can be evaluated, in particular, temporally closely and, in particular, fully automatically.

Furthermore, it is proposed that at least one prompting message is generated if a deviation from the normal state of the property is detected during the evaluation of the evaluation data set, for example if a defined threshold value is exceeded. In this case, the notification can be displayed and/or transmitted to an external electronic unit, such as, for example, an evaluation unit, a diagnostic unit, a laptop and/or a smartphone or the like, in particular by means of a display unit of the vehicle and/or of the steering system, such as, for example, a warning light. In particular, an advantageous reminder function and/or warning function can thereby be realized. In particular, information can thereby be detected, in particular about defects in the chassis and/or the steering system of the vehicle, such as problems, for example loss of balance weight, tie rod play or wheels, and transmitted to the driver and/or the service station.

In a further embodiment of the invention, it is provided that, in order to at least partially compensate for steering wheel rotational vibrations, at least when using an evaluation data record and/or a combination of a plurality of evaluation data records from different other vehicles, the transfer function for generating the compensation signal, in particular the transfer function already mentioned above, is adapted, in particular once as by software updating, for example, and/or permanently (as by means of a regulator circuit, for example). This advantageously enables the compensation characteristic to be adapted during operation of the vehicle, as a result of which, in particular, recalls and/or complaints can be reduced.

Furthermore, it is preferably provided that, for the purpose of adapting the transfer function, a machine-friendly learning algorithm, such as, for example, an artificial neural network, is used, which is provided for optimizing at least a partial compensation of the steering wheel rotational vibrations at least on the basis of the evaluation data set. In this case, it is advantageous to learn typical and in particular fault-free characteristics of the steering device by means of a learning algorithm, wherein steering wheel rotational vibrations are minimized. Preferably, the learning algorithm corresponds to a data-driven learning algorithm, wherein a plurality of acquired and/or available data and/or parameters of the steering device, the steering system and/or the vehicle are advantageously used and/or associated with one another. The learning algorithm can be stored in the memory of the computing unit or be part of a central, external computer system. In particular, this makes it possible to achieve an advantageously simple and/or automatic optimization, wherein in particular an unambiguous specification and/or adaptation of the transfer function can be dispensed with.

In particular, when at least one further evaluation data set and preferably a plurality of further evaluation data sets, in particular further evaluation data sets from a further vehicle and preferably a plurality of further vehicles, preferably identical vehicle variants, are acquired for the purpose of evaluation and/or for at least partial compensation of steering wheel rotational vibrations and combined with the evaluation data, a particularly high level of effectiveness of the favorable recording and/or compensation properties of the overall coverage phenomenon can be achieved. In particular, the evaluation data set can also be used here to create a common heat map. Furthermore, data for vehicle variants and for each individual vehicle can be collected and evaluated in particular thereby.

The method for analyzing and/or at least partially compensating for steering wheel rotational vibrations should not be limited to the above-described applications and embodiments. In particular, the method for analyzing and/or at least partially compensating for the steering wheel rotational vibrations may have a different number than the number of individual elements, components and units described herein in order to satisfy the functional manner described herein.

Drawings

Other advantages are given by the following description of the figures. An embodiment of the invention is shown in the drawings. The figures, description and claims contain a number of combinations of features. The person skilled in the art can also appropriately consider these features individually and conclude other combinations of significance.

In which is shown:

figures 1a-b show in simplified diagrams an exemplary vehicle with a steering system comprising a steering device,

figure 2 shows a schematic illustration of a signal flow diagram for analyzing and/or at least partially compensating steering wheel rotational vibrations,

figure 3 shows a diagram of a heatmap created by evaluating a data set,

figure 4 shows a diagram of a further heat map created by evaluating a data set,

figure 5 shows a diagram of the state characteristic of the activation unit of the steering device,

FIG. 6 shows an exemplary flow chart of main method steps of a method for analyzing and/or at least partially compensating steering wheel rotational vibrations, and

FIG. 7 illustrates an exemplary system including a plurality of steering devices.

Detailed Description

Fig. 1a and 1b show a vehicle 10, which is designed as a motor vehicle and has a plurality of wheels 36 and a steering system 38, in a simplified illustration. A steering system 38 is operatively connected to the wheels 36 and is configured to influence the direction of travel of the vehicle 10.

The steering system 38 includes a steering device. The steering device has a steering gear 40. The steering gear mechanism 40 is configured as a rack and pinion steering gear mechanism. The steering gear 40 includes a steering pinion 42 and a rack 44 mechanically coupled to the steering pinion 42. The steering gear 40 is operatively connected to at least two of the wheels 36, in particular two front wheels of the vehicle 10. The steering gear 40 is provided for inducing a pivoting and/or rotating movement of the wheels 36. The steering gear 40 is provided for converting a steering preset value into a steering movement of the wheels 36. In principle, however, the steering gear can also be designed as a worm gear steering gear, as a helical spindle steering gear and/or as a ball-and-socket steering gear.

The steering device also includes at least one steering linkage 46. In the present case, the steering device comprises a steering linkage 46 on each vehicle side, which mechanically connects the steering gear 40, in particular the rack 44, to one of the wheels 36. In principle, however, it is also conceivable to dispense with the steering linkage and/or to integrate the steering linkage into the steering gear.

Furthermore, the steering device comprises a steering wheel 48. The steering wheel 48 is arranged on the side of the steering system 38 facing the driver. The steering wheel 48 is used to apply a manual steering torque. The steering wheel 48 is provided for manual control of the direction of travel of the vehicle 10. The steering wheel 48 is provided to introduce a manual steering torque into the steering gear 40 and thus to the wheels 36.

In order to connect the steering wheel 48 to the steering gear 40, the steering device furthermore comprises a steering column 50. In the present case, the steering column 50 permanently, in particular mechanically, connects the steering wheel 48 to the steering gear 40. The steering column 50 is provided at least for transmitting a manual steering torque, in particular exerted by the driver, to the steering mechanism 40. Furthermore, the steering column 50 comprises at least one torsion element 52 (in the present case in particular a torsion bar) and a steering spindle 54 for accommodating the torsion element 52. Alternatively, the steering column may also connect the steering wheel to the steering gear only temporarily, as is the case, for example, with vehicles having autonomous driving operation. In principle, it is also conceivable to dispense with the steering spindle and/or the torsion element. Furthermore, the steering device may additionally comprise at least one intermediate shaft.

Furthermore, the steering device comprises in the present case an auxiliary unit 56 for generating and/or providing steering assistance. The auxiliary unit 56 is electrically constructed. The auxiliary unit 56 has a functional connection to the steering gear 40. The auxiliary unit 56 comprises a motor 58, in the present case in particular designed as an electric motor, and a drive pinion 60 mechanically coupled to the rack 44. The auxiliary unit 56 is provided for introducing an auxiliary torque into the steering gear 40, in particular by driving the pinion 60. The assistance unit 56 is provided for assisting a manual steering torque, in particular a manual steering torque applied by the driver. Alternatively, however, the auxiliary unit can also be at least partially hydraulically designed. Furthermore, in particular instead of a drive pinion, the auxiliary unit can also comprise, for example, a belt, preferably with a ball screw drive (kugelgewendetrieb). Furthermore, an auxiliary unit can also be provided for introducing an auxiliary torque into the steering column.

Furthermore, the steering device has a detection unit 28. The detection unit 28 is arranged in the region of the torsion element 52 and/or of the steering spindle 54. The detection unit 28 has a functional connection to the torsion element 52 and/or the steering spindle 54. The detection unit 28 is provided for the contactless detection of the detection signal 12, in the present case in particular of a torque signal on the steering spindle side. For this purpose, the detection unit 28 comprises, by way of example, exactly one detection element 62, in particular in the form of a torque sensor. Alternatively, however, the detection unit may also comprise a plurality of detection elements and/or be provided for detecting a rotor position angle, a rotor speed, a motor actual torque and/or a wheel speed characteristic.

Furthermore, the steering device has a control 34. The controller 34 includes a computing unit 30. The computation unit 30 is electronically configured. The calculation unit 30 comprises at least one processor 64, for example in the form of a microprocessor, and at least one memory 66. Furthermore, the computation unit 30 comprises at least one operating program stored in the memory 66, which operating program has at least one computation program, at least one control program, at least one evaluation program and at least one compensation program.

The controller 34, in particular the computation unit 30, has an operative connection with the detection unit 28. In the present case, the controller 34 is electrically connected to the detection unit 28, for example by means of a data connection and/or a bus system. The calculation unit 30 is at least provided here for receiving the detection signal 12 and/or a signal related to the detection signal 12 from the detection unit 28.

Furthermore, the controller 34, in particular the computation unit 30, has a functional connection to an auxiliary unit 56. In the present case, the controller 34 is electrically connected to the auxiliary unit 56, for example by means of a data connection and/or a bus system. In this case, the computing unit 30 is provided at least for actuating the motor 58 and thus in particular for adjusting the assistance torque, in particular as a function of the detection signal 12.

Further, the vehicle 10 includes a communication unit 68. The communication unit 68 is configured as a central communication unit ("CCU"). The communication unit 68 is arranged for wireless communication, such as for example via a mobile radio connection and/or a WLAN connection or the like. Alternatively or additionally, the vehicle may also have a communication interface, in particular a vehicle diagnostic interface, such as, for example, an OBD2 socket. Furthermore, the steering system and/or the steering device may in principle also comprise a further communication unit which is additional and in particular separate from the communication unit of the vehicle.

Steering wheel rotational vibrations may now occur during driving operation of the vehicle 10, in particular in the critical speed range between 80 km/h and 140 km/h. The steering wheel rotation vibrations are caused, for example, by an imbalance in the brake disc ("brake judder") and/or an imbalance in the wheel ("shim-my"). Such a steering wheel rotation vibration is usually perceived as disturbing by the driver and is therefore advantageously at least partially compensated by means of different measures.

Fig. 2 shows a signal flow diagram for at least partially compensating for steering wheel rotational vibrations during operation of the steering device.

In the present case, the computation unit 30 is at least provided to carry out a method for at least partially compensating for the steering wheel rotational vibrations, in particular by means of a compensation program and a transfer function stored in the memory 66, and for this purpose has in particular a computer program with corresponding program coding means.

The detection signal 12 is detected by means of the detection unit 28 and fed to a filter unit 70 of the steering device for filtering. Furthermore, the current wheel frequency 16 is detected from the current wheel speed characteristic and is likewise supplied to the filter unit 70. The current wheel speed characteristic advantageously corresponds to an average value of the wheel speeds of the wheels 36 and can be detected, for example, by means of a sensor unit and/or retrieved from a vehicle controller or a vehicle bus system. In the present case, the filter unit 70 is designed as a frequency-variable bandpass filter, the resonance frequency of which is set using the wheel frequency 16. The filter unit 70 may be integrated into the detection unit 28 or the controller 34, for example. Alternatively, however, the filter unit 70 may also be constructed separately from the detection unit 28 and the controller 34. The filter unit 70 filters the detection signal 12 based on the wheel frequency 16 and generates a filtered detection signal 72. In principle, however, it is also conceivable to dispense with filtering of the detection signal.

The filtered detection signal 72 is then fed to a compensation unit 74 of the calculation unit 30, in which a compensation program is stored. The compensation unit 74 generates a compensation signal 26, in particular a compensation motor torque, using the transfer function, which is supplied to the auxiliary unit 56 for at least partially compensating the steering wheel rotation oscillations.

Furthermore, the computation unit 30 comprises an activation unit 24, which is operatively connected to the compensation unit 74 and can act in particular in a controlled manner on the compensation unit 74. The activation unit 24 is provided to activate and/or deactivate the compensation of the steering wheel rotational vibrations by means of the compensation unit 74 as a function of operating parameters of the vehicle 10, such as, for example, the current vehicle speed, the current steering angle and/or the current load of the on-board electrical system. For this purpose, activation unit 24 has a plurality of state parameters 22, such as, for example, "compensation active", "compensation inactive" and/or "waiting", which define the state of activation unit 24 and/or of compensation unit 74.

Furthermore, the computation unit 30 is provided for carrying out a method for evaluating and/or for at least partially compensating for steering wheel rotational vibrations, in particular by means of an evaluation program, and for this purpose in particular has a further computer program with corresponding further program coding means.

In this case, the test signal 12 is detected by means of the detection unit 28 and a disturbance variable 14, in particular a disturbance amplitude, which is dependent on the steering wheel rotation oscillation is extracted from the test signal 12. In order to extract the interference characteristic variable 14, the detection signal 12 is additionally filtered by means of a filter unit 70 on the basis of the wheel frequency 16. In the present case, the interference characteristic 14 is therefore identical to the filtered detection signal 72. In principle, however, the interference characteristic 14 can also differ from the filtered detection signal 72. Furthermore, filtering of the detection signal can be omitted for the purpose of extracting the interference characteristic variable.

Subsequently, at least the time variation of the disturbance variable 14 and the time variation of the wheel frequency 16 are monitored and combined into a common evaluation data set 18 during the entire monitoring time interval, which is in particular relevant for the service life of the steering device, the steering system 38 and/or the vehicle 10.

The evaluation data set 18 is then used to create a heat map (see in particular fig. 3) for the purpose of analyzing the steering wheel rotation vibrations. Additionally or alternatively, the time rate of change of the disturbance variable 14 and/or of the wheel frequency 16 can be determined in the evaluation data set 18 and also taken into account for evaluating the steering wheel rotational vibrations (see fig. 4 in particular). Furthermore, the state characteristic variables 22 of the activation unit 24 can be read and likewise collected in the evaluation data set 18 for evaluation of the steering wheel rotational vibrations (see in particular fig. 5). Furthermore, further evaluation data sets 20 from further vehicles 11 can also be acquired and combined with the evaluation data set 18 (see in particular fig. 7). The evaluation data record 18 can then be transmitted wirelessly, for example after a longer period of time, for example several months, via the communication unit 68 to an external evaluation unit (not shown), such as, for example, via a mobile radio connection and/or a WLAN connection or the like, so that an advantageously focused evaluation of the evaluation data record 18 can be achieved. Alternatively, however, the evaluation data set can also be evaluated in the computing unit. In addition, any type of chart other than a heat map may be used to analyze the steering wheel rotation vibration. The evaluation of the evaluation data set can also be carried out at regular time intervals, for example of days or weeks.

The analysis unit then checks whether there is a characteristic deviating from the normal state. If a deviation from the normal state is detected during the evaluation of the evaluation data set 18, in the present case, in particular by means of the evaluation unit, a warning message is generated which is subsequently displayed by means of a display unit 76 of the vehicle 10, such as, for example, a warning light, and/or transmitted to an external electronic unit, such as, for example, a service station, so that, in particular, an advantageous warning function and/or warning function can be implemented.

In order to improve at least partial compensation for the steering wheel rotational vibrations, the evaluation data set 18 can also be used to adapt the transfer function. For this purpose, the evaluation data set has an operative connection with the compensation unit 74. The transfer function can be adapted in this case once (for example, by a software update) and/or permanently (for example, by means of a regulator loop). Furthermore, for adapting the transfer function, a machine learning algorithm, such as, for example, an artificial neural network, is advantageously used, which is provided for optimizing at least a partial compensation of the steering wheel rotational vibrations at least on the basis of the evaluation data set 18.

FIG. 3 illustratively shows a diagram of a heat map created by the evaluation data set 18. On the ordinate axis 78, the interference characteristic value 14 is plotted, in particular in Nm, as the interference amplitude. The wheel frequency 16 in [ Hz ] is shown on the abscissa axis 80. The temperature scale is a frequency criterion in which, in particular, the disturbance variable 14 and the wheel frequency 16 are in a predefined state. In the present case, the interference characteristic 14 is observed, for example, in 0.1 Nm steps in the interval between 0 Nm and 0.5 Nm. Advantageously, however, the interference characteristic 14 can also be observed in the interval between 0 Nm and 0.3 Nm. Furthermore, the wheel frequency 16 is illustratively observed in 1 Hz steps in the interval between 9 Hz and 18 Hz.

As can be seen from fig. 3, the disturbance variable 14 is essentially in the range between 0.2 Nm and 0.4 Nm and the wheel frequency 16 is in the range between 13 Hz and 15 Hz, so that steering wheel rotational vibrations are cumulatively present in this range at least in the vehicle 10 under consideration.

Fig. 4 exemplarily shows a diagram of a further heatmap established by the evaluation data set 18. In turn, an interference characteristic quantity 14, which is in particular designed as an interference amplitude, is plotted on the ordinate axis 82, wherein the interference characteristic quantity 14 is observed, for example, in steps of 0.1 Nm in the interval between 0 Nm and 0.5 Nm. Advantageously, however, the interference characteristic 14 can also be observed in the interval between 0 Nm and 0.3 Nm. The wheel frequency 16 in [ Hz ] is again shown on the abscissa axis 84, wherein the wheel frequency 16 is observed in an interval between 9 Hz and 18 Hz, for example in steps of 1 Hz. The temperature scale in this case represents the time rate of change in the respective predefined state.

In this case, according to fig. 4, for example, the differences between the disturbance variable 14 and the wheel frequency 16 for different seasons and in particular for different tires of the vehicle 10 can be determined. Furthermore, with the aid of fig. 4, wear, damage, defects and/or gaps, for example, in the steering system 38 and/or in the vehicle 10 can also be detected.

Fig. 5 shows a diagram of the state parameter 22 of the activation unit 24. The time, in particular the dwell time of the activation unit 24 in the respective state, is plotted on the ordinate axis 86 with h. On the abscissa axis 88, various state parameters 22 are shown. In the present case, the activation unit 24 here comprises, by way of example, seven different state characteristics 22 and/or states, such as, for example, "compensation active", "compensation inactive", "waiting", "compensation entry", "compensation exit", "compensation possible" and/or "compensation impossible". Alternatively, however, the activation unit may also comprise exactly two state characteristics and/or states, in particular "compensation activated" and "compensation deactivated", and/or any other number of state characteristics and/or states.

Fig. 6 also shows an exemplary flow chart with the main method steps of a method for analyzing and/or at least partially compensating for steering wheel rotational vibrations.

In a method step 100, the detection signal 12 is detected by means of the detection unit 28.

In method step 102, wheel frequency 16 is determined, which is correlated with the current wheel speed characteristic.

In a method step 104, the detection signal 12 is filtered by means of the filter unit 70 on the basis of the wheel frequency 16, and a disturbance variable 14 associated with the steering wheel rotational oscillation is extracted.

In method step 106, the time changes of the disturbance variable 14 and of the wheel frequency 16 are monitored during the entire monitoring time interval.

In a method step 108, an evaluation data set 18 is then created from the acquired data and evaluated for the purpose of evaluating and/or at least partially compensating for the steering wheel rotational vibrations.

Optional method steps such as, for example, creating a heat map, acquiring the time rate of change in the evaluation data record 18, taking into account the state parameters 22 of the activation unit 24, generating a notification of a prompt and/or adapting the transfer function using the evaluation data record may then be carried out.

Fig. 7 shows a system 32 comprising a plurality of, in the present case two, vehicles 10, 11, each comprising a steering device according to the invention. In principle, however, the system may comprise any number of further vehicles with a steering device according to the invention. Each steering device comprises a respective evaluation data set 18, 20, which are combined with one another in the present case for the purpose of evaluating and/or at least partially compensating for steering wheel rotational vibrations. For this purpose, the system 32 has a data memory 90, which is particularly central and is advantageously operatively connected to the evaluation unit and is provided for combining all the evaluation data sets 18, 20.

The evaluation data records 18, 20 can then be used, for example, to create a common thermal map, from which the steering wheel rotational vibrations of the individual vehicles 10, 11 of a particular vehicle type and/or of a particular vehicle type can be analyzed, identified and/or at least partially compensated.