DE102021210320B3 - Method and system for controlling a vehicle - Google Patents

Abstract

The invention relates to a method for lateral control of a vehicle, the vehicle comprising a steering angle controller (2) and an electromechanical steering system (3), a steering dynamics model (4) of the electromechanical steering system being implemented in the steering angle controller (2), which is based on steering torque information (TM) or a variable proportional thereto provides estimated steering angle information (δP), based on the estimated steering angle information (δP) and the measured steering angle (δC) of the electromechanical steering (3) modified steering angle information (δM) is calculated, and based on a control deviation (δE) of the steering angle controller (2) is calculated on the basis of the modified steering angle information (δM) and a steering angle specification (δR).

Description

The invention relates to a method and a system for lateral control, a method and a system for lateral control of a vehicle is disclosed, which uses a controller concept based on a Smith predictor in order to increase the dynamics of the steering angle control.

It is common knowledge that with lateral vehicle control functions (lane guidance assistant, lane departure warning etc.) a steering angle controller is used to influence the lateral vehicle guidance, in particular to keep the vehicle in the middle of the lane or to change lanes.

Bus communication, the use of gateways and other hardware or software-related delays result in high latencies in the controlled system, which negatively affect the dynamics and thus the precision of the steering system.

From the DE 10 2011 002 997 A1 is known to operate a theoretical steering system model in addition to a real steering system. An estimate determined from a first measured steering system signal in the steering system model is compared to a second measured steering system signal to identify driver influence. Hands-free driving can thus be detected.

From the generic DE 602 20 610 T2 there is known an electric power steering apparatus having a steering torque sensor and a controller for controlling a steering assist motor based on the steering torque. To control the servomotor, a measured steering angle is compared with a modeled standard steering angle.

Proceeding from this, it is the object of the invention to specify a method for lateral control of a vehicle which, despite high latencies in the area of the controlled system, enables a steering system with high dynamics and precision.

The object is solved by a method having the features of independent patent claim 1 . A system for lateral control of a vehicle is the subject of independent claim 10. Preferred embodiments are the subject of the dependent claims.

According to a first aspect, a method for lateral control of a vehicle is disclosed. The vehicle's steering system includes a steering angle controller and an electromechanical steering system. A steering dynamics model of the electromechanical steering is implemented in the steering angle controller, which provides estimated steering angle information based on steering torque information or a variable proportional thereto, for example the current strength of the electrical current flowing through the steering actuator. Modified steering angle information is calculated based on the estimated steering angle information and the measured steering angle of the electromechanical steering system, for example provided by a steering angle sensor. Based on this modified steering angle information and a steering angle specification, which the steering angle controller receives as an input variable from a higher-level unit, for example, a system deviation of the steering angle controller is calculated. On the basis of the control deviation, the steering torque information or a variable proportional thereto is calculated, for example, via a functional unit of the steering angle controller.

The disclosed method has the technical advantage that the use of the steering dynamics model allows an essentially delay-free estimation of the steering angle, referred to here as estimated steering angle information. The use of this estimated steering angle information to generate the steering angle information fed back to the controller input and thus to generate the controller deviation enables the steering system dynamics and the steering precision to be improved. By using the steering dynamics model, the steering system follows the damping characteristics mapped in the steering dynamics model. The method according to the invention can thus also be used in the case of electromechanical steering systems which only have weak damping or no interface for influencing the damping of the electromechanical steering system from the outside.

According to one exemplary embodiment, the steering dynamics model receives a steering disturbance variable that results from a lateral force applied to the vehicle. The estimated steering angle information is calculated by the steering dynamics model based on the steering torque information or a quantity proportional thereto and the steering disturbance quantity. This makes it possible to use not only the steering torque information, which influences the steering angle of the steering system, but also the moments resulting from the lateral forces acting on the vehicle to determine the estimated steering angle information.

According to one embodiment, based on the estimated steering angle information and the measured steering angle of the electromechanical steering, a model deviation in formation calculated. The model deviation information is then filtered using a filter unit. The modified steering angle information is then generated based on the filtered model deviation information and the estimated steering angle information. The filter unit makes it possible to specify the degree to which the steering angle control is influenced by disruptive factors such as disruptive moments and disruptive forces or measurement noise, but also modeling errors.

According to one exemplary embodiment, the model deviation information is obtained in that the estimated steering angle information is delayed by means of a delay element and is subtracted from the measured steering angle of the electromechanical steering. The time delay of the delay element is preferably selected in such a way that the time delay caused by the delay element corresponds to the time delay exhibited by the controlled system of the steering system. The model deviation information is thus obtained by forming the difference between the measured steering angle information and the delayed, estimated steering angle information.

According to one exemplary embodiment, the filter unit, by means of which the model deviation information is filtered, has an adjustable amplification factor, which can be set adaptively as a function of the driving situation. As a result, the steady-state controller accuracy can be adjusted dynamically, depending on one or more parameters that indicate the current driving situation.

According to one exemplary embodiment, the steering angle controller has a controller unit with a disturbance estimator, the steering disturbance variable being estimated by means of the disturbance estimator based on information that indicates the lateral force acting on the vehicle. It is thus possible to also take into account interference factors affecting the steering, such as side wind, road gradient, vehicle mass, etc., when determining the estimated steering angle information using the steering dynamics model.

According to one embodiment, the disturbance estimator estimates the steering disturbance variable using a Kalman filter. In particular, the disturbance estimator uses a mathematical model to estimate the steering disturbance variable and uses additional measurement information provided as inputs to the Kalman filter (e.g. vehicle speed changes, steering angle rate, etc.) to correct the estimates. As a result, the steering disturbance quantity can be determined with higher estimation accuracy.

According to one exemplary embodiment, the controller unit has a functional unit, by means of which a control deviation resulting from the steering angle specification and the modified steering angle information is converted into moment information, i.e. torque information. The functional unit can in particular be a proportional control element. Alternatively, the functional unit can also have a PD control element or another controller, for example a compensation controller, a state controller, or a non-linear controller, for example a sliding mode controller. The moment information is converted into malfunction-compensated moment information based on the steering disturbance variable or information derived therefrom. This means that the disturbance-compensated torque information has a first torque component, which results from the control deviation, and a second torque component, which results from the steering disturbance variable caused by the lateral force. As a result, steering torque information can be made available to the electromechanical steering system, which also takes into account the moments occurring in the steering, which result from lateral forces acting on the vehicle.

According to one exemplary embodiment, the disturbance-compensated moment information is converted into the steering torque information by means of a limiter, with the steering torque information being transmitted to the electromechanical steering system. For example, the amplitude and the gradient of the steering torque information can be limited by the limiter so that, for example, predetermined safety criteria can be complied with.

According to one exemplary embodiment, a mathematical model is used as the steering dynamics model that does not have any model parameters for modeling external interference influence dependencies. The external disturbances are only taken into account by the steering disturbance variable. As a result, the mathematical steering dynamics model can be simplified and a cumbersome determination of model parameters for the different load cases and disturbance variables can be avoided.

According to a further aspect, the invention relates to a system for lateral control of a vehicle, which includes a steering angle controller and an electromechanical steering system. A steering dynamics model of the electromechanical steering is implemented in the steering angle controller. The steering dynamics model is designed to provide estimated steering angle information based on steering torque information or a variable proportional thereto. The steering angle The controller is designed to calculate modified steering angle information based on the estimated steering angle information and the measured steering angle of the electromechanical steering. Furthermore, the steering angle controller is designed to calculate a system deviation based on the modified steering angle information and a steering angle specification.

According to one exemplary embodiment of the system, the steering dynamics model is designed to calculate the estimated steering angle information based on a steering disturbance variable that results from a lateral force applied to the vehicle and the steering torque information or a variable proportional thereto. This makes it possible, in addition to the steering torque information that influences the steering angle of the steering system, to also use torques that result from lateral forces acting on the vehicle to determine the estimated steering angle information.

According to one exemplary embodiment of the system, the steering angle controller is designed to calculate model deviation information based on the estimated steering angle information and the measured steering angle of the electromechanical steering system, to filter the model deviation information using a filter unit, and to generate the modified steering angle information based on the filtered model deviation information and the estimated steering angle information . The filter unit makes it possible
as a further degree of freedom to influence the effect of disturbances, modeling errors and measurement noise on the steering angle control.

According to one exemplary embodiment of the system, the filter unit, by means of which the model deviation information is filtered, has an adjustable amplification factor, which can be set adaptively as a function of the driving situation. As a result, the steady-state controller accuracy can be adjusted dynamically, depending on one or more parameters that indicate the current driving situation.

According to one exemplary embodiment of the system, the steering angle controller has a controller unit with a disturbance estimator, the disturbance estimator being designed to estimate the steering disturbance variable based on information that specifies the lateral force acting on the vehicle. It is thus possible to also take into account interference factors affecting the steering, such as side wind, road gradient, vehicle mass, etc., when determining the estimated steering angle information using the steering dynamics model.

According to an exemplary embodiment of the system, the disturbance estimator has a Kalman filter for estimating the steering disturbance variable. In particular, the disturbance estimator uses a mathematical model to estimate the steering disturbance variable and uses additional measurement information provided as inputs to the Kalman filter (e.g. vehicle speed changes, steering angle rate, etc.) to correct the estimates. As a result, the steering disturbance quantity can be determined with higher estimation accuracy.

The terms “approximately”, “substantially” or “roughly” mean deviations from the exact value by +/-10%, preferably by +/-5% and/or deviations in the form of changes that are insignificant for the function .

Further developments, advantages and possible applications of the invention also result from the following description of exemplary embodiments and from the figures. All of the features described and/or illustrated are fundamentally the subject matter of the invention, either alone or in any combination, regardless of how they are summarized in the claims or how they relate back to them. The content of the claims is also made part of the description.

• 1 beispielhaft eine schematische Darstellung eines Systems zur Querregelung eines Fahrzeugs, das eine elektromechanische Lenkung und einen Lenkwinkelregler aufweist; und
• 2 beispielhaft eine schematische Darstellung der Funktionseinheiten des Lenkwinkelreglers, der in dem System zur Querregelung eines Fahrzeugs gemäß 1 verwendet werden kann.

The invention is explained in more detail below with reference to the figures of exemplary embodiments. Show it:

• 1 by way of example, a schematic representation of a system for lateral control of a vehicle, which has an electromechanical steering system and a steering angle controller; and
• 2 exemplary a schematic representation of the functional units of the steering angle controller, which is in the system for transverse control of a vehicle according to 1 can be used.

1 shows, by way of example and schematically, a system 1 for lateral or transverse control of a vehicle, which is equipped with an electromechanical steering system 3 and a steering angle controller 2 for controlling the steering system.

As in 1 As can be seen, the steering angle controller 2 is coupled to the electromechanical steering system 3 and provides steering torque information T _M . This steering torque information T _M is received by the electromechanical steering system 3 and optionally further processed by a control unit in order to control the electric steering actuator. By the electric steering actuator the steering angle of the electromechanical steering system 3 changes, with a steering angle sensor providing measured steering angle information δ _c .

To increase the steering dynamics, the steering angle controller 2 has a controller architecture based on a Smith predictor. The steering angle controller uses a model that describes the controlled system, i.e. a model of the electromechanical steering system 3, to predict future controlled variable curves, i.e. to predict the steering angle of the electromechanical steering system, in order to reduce the system-related latencies of the steering angle control and thus increase the dynamics and precision of the steering angle control to enhance.

The steering torque information T _M is provided by a controller unit 7 of the steering angle controller 2 . The steering torque information T _M is a measure of the torque that the steering actuator is intended to apply to the vehicle's steering system.

This steering torque information T _M is transmitted to a steering dynamics model 4 that models the electromechanical steering. The steering dynamics model 4 provides estimated steering angle information based on this steering torque information T _M .

A steering disturbance variable T _L is preferably also provided by the controller unit 7 . The steering disturbance variable T _L indicates, for example, the moment that occurs on the steering rack of the steering system due to lateral forces that act on the wheels of the vehicle. If the controller unit 7 provides the steering disturbance variable T _L , this steering disturbance variable T _L is also transmitted to the steering dynamics model 4 in order to be able to use the steering dynamics model 4 to simulate the steering angle influences that are caused by lateral forces acting on the vehicle, in particular on the tires of the vehicle.

The steering dynamics model 4 can be formed, for example, by a PT element, for example a second-order PT element. The transfer function of the steering dynamics model 4 can be specified, for example, in the Laplace domain as follows: $$\frac{{\delta }_p}{T_M-T_L}=\frac{K}{T^2{s}^2+2DTs+1};$$

• δ_P: geschätzte Lenkwinkelinformation [grad];
• T_M: Lenkdrehmomentinformation [Nm];
• T_L: Lenkstörgröße aufgrund Lateralkräfte am Fahrzeug [Nm];
• K: Filter-Verstärkungsfaktor [grad/Nm];
• T: Filterzeitkonstante [s];
• D: Dämpfung.

where:

• δ _P : estimated steering angle information [grad];
• T _M : steering torque information [Nm];
• T _L : steering disturbance due to lateral forces on the vehicle [Nm];
• K: filter gain factor [grad/Nm];
• T: filter time constant [s];
• D: Attenuation.

The model parameters K, T and D are vehicle-specific parameters and are determined either by simulation or measurements. In particular, it should be noted that the model parameters K, T and D do not depend on external influences (e.g. road surface conditions, side wind, curbs). This means that the model can be used for a road surface condition (e.g. dry road) that leads to a high adhesion coefficient between road surface and tires as well as for a road condition (e.g. icy road) that leads to a low adhesion coefficient between the road and the tires.

By including the steering disturbance variable T _L in the steering dynamics model 4, external disturbances acting on the vehicle can also be taken into account by the steering dynamics model 4 when predicting or estimating the steering angle information.

If a steering dynamics model 4 is used that does not take into account the steering disturbance variable T _L , the transfer function of the steering dynamics model 4 can be as follows: $$\frac{{\delta }_p}{T_M}=\frac{K}{T^2{s}^2+2DTs+1};$$

• δ_P: geschätzte Lenkwinkelinformation [grad];
• T_M: Lenkdrehmomentinformation [Nm];
• K: Filter-Verstärkungsfaktor [grad/Nm];
• T: Filterzeitkonstante [s];
• D: Dämpfung.

where:

• δ _P : estimated steering angle information [grad];
• T _M : steering torque information [Nm];
• K: filter gain factor [grad/Nm];
• T: filter time constant [s];
• D: Attenuation.

The estimated steering angle information provided by the steering dynamics model 4 is then transmitted to a delay element 5 . The delay element 5 implements the delay that the electromechanical steering system 3 has, ie the time delay that elapses between a change in the steering torque information T _M and a change in the measured steering angle (ie latency of the steering system).

The delay can be described in the Laplacian domain as follows: $$\frac{{\delta }_{DP}}{{\delta }_P}=e^{-\tau s};$$

• δ_P: geschätzte Lenkwinkelinformation [grad];
• δ_DP: verzögerte geschätzte Lenkwinkelinformation [grad];
• τ: Verzögerungszeit [s].

where:

• δ _P : estimated steering angle information [grad];
• δ _DP : delayed estimated steering angle information [grad];
• τ: delay time [s].

The delay can be implemented by means of a daisy chain, for example.

The delay element 5 provides delayed estimated steering angle information δ _DP at its output. This delayed estimated steering angle information δ _DP is fed together with the measured steering angle information δ _C to a subtraction point at which the delayed estimated steering angle information δ _DP is subtracted from the measured steering angle information δ _C (δ _C - δ _DP ). This subtraction results in model deviation information D _δ which indicates how high the error is between the measured steering angle information δ _C and the model-based steering angle information δ _DP (here the delayed estimated steering angle information).

The steering angle controller 2 preferably has a filter unit 6 . This filter unit receives the model deviation information D _δ and provides filtered model deviation information F _δ based thereon.

The filter unit 6 can be formed by a PT element, for example. In particular, the filter unit 6 can have a transfer function of a PT1 element. The filter unit 6 makes it possible to filter out interference or measurement noise.

The transfer function of the filter unit 6 can be described, for example, by the following equation: $$\frac{f_{\delta }}{D_{\delta }}=\frac{K_{ƒ}}{Ts+1};$$

• F_δ: gefilterte Modellabweichungsinformation;
• D_δ: Modellabweichungsinformation;
• K_f: Filter-Verstärkungsfaktor;
• T: Filterzeitkonstante.

where:

• F _δ : filtered model deviation information;
• D _δ : model deviation information;
• K _f : filter gain;
• T: filter time constant.

The steady-state controller accuracy can be adjusted by choosing the gain factor of the filter _Kf . In this case, the amplification factor K _f can assume values in the range between 0 and 1. With a value of Kf=1, maximum steady-state control accuracy is achieved. With a value of K _f =0, a low steady-state control accuracy is achieved and the controller works purely as a feedforward controller.

As in 1 As can be seen, the filtered model deviation information F _δ is transmitted to a summation point at which the model deviation information F _δ and the estimated steering angle information δ _P are added. The modified steering angle information δ _M is obtained by this addition. This modified steering angle information δ _M is then transmitted to the controller unit 7 as a feedback variable. In particular, the modified steering angle information δ _M is subtracted from the steering angle specification δ _R , which is provided to the controller unit 7 as an input signal, in order thereby to form the control deviation δ _E .

2 shows a block diagram of an exemplary embodiment of the control unit 7 by way of example and schematically. As explained above, the control unit 7 forms the controller of the steering angle control. The control unit 7 receives a plurality of pieces of input information, for example the steering angle specification δ _R and the feedback variable in the form of the modified steering angle information δ _M and, based thereon, provides output information which contains at least the steering torque information T _M or a variable proportional thereto (for example current information for the electric actuator). includes. The control unit 7 preferably also provides the steering disturbance variable T _L as an estimated variable, which indicates, for example, the moment occurring on the steering rack of the steering system due to lateral forces acting on the wheels.

The control unit 7 preferably also receives speed information v _ego , which indicates the vehicle's own speed. The steering angle control or the estimation of the steering disturbance variable T _L can thus take place as a function of the vehicle speed, in particular also as a function of the change in the vehicle speed (by accelerating or braking).

As in 2 As can be seen, the control unit 7 preferably includes a disturbance estimator 7.1. Disturbance estimator 7.1 is designed to estimate steering disturbance variable T _L based on information about a lateral force F _Lat present on the vehicle, in particular on the wheels of the vehicle.

In addition to the information on the lateral force _FLat , the disturbance estimator 7.1 preferably also receives information on the vehicle's own speed (velocity information v _ego ) and the modified steering angle information δ _M , ie the returned variable of the control loop. In addition, the disturbance estimator 7.1 also receives delayed steering torque information T _Md , which is obtained, for example, by means of a delay element 7.4 from the steering torque information T _M provided at the output. The delay element 7.4 can cause a delay of one clock pulse or more, for example. By using the modified steering angle information δ _M instead of the measured steering angle information δ _c provided by the steering angle sensor, the delay in the steering torque information T _M can be greatly reduced (only one cycle instead of the overall latency of the steering system), since the modified steering angle information δ _M is based on the model-based estimation of the Steering angle information δ _P has a higher dynamic than the measured steering angle information δ _c , which leads to improved dynamics and precision of the steering angle control.

The disturbance estimator 7.1 preferably contains a Kalman filter for estimating the steering disturbance variable T _L . By using the Kalman filter, the steering disturbance variable T _L can first be predicted using a model and this prediction can be corrected based on the measured values received as input variables. In addition, it is possible by means of the Kalman filter to adapt the influence of the underlying mathematical model or the measured values used for the correction on the estimate of the steering disturbance variable T _L depending on the driving situation. It is thus possible, for example, that in driving situations in which the mathematical model is known to have larger prediction errors, for example in the case of steering movements or changes in the speed of the vehicle, the covariance matrices used for the estimation can be adjusted in order to improve the estimation accuracy.

The control unit 7 also includes a functional unit 7.2, by means of which the control deviation δ _E is converted into torque information T _P . Functional unit 7.2 can be a proportional controller, for example, which calculates torque information T _P (ie torque values) from control deviation δ _E using a transmission factor. The functional unit 7.2 can preferably receive the information on the vehicle's own speed v _ego . Based on this vehicle speed information v _ego the transmission factor can be adjusted. The transfer factor is preferably changed as a function of speed in such a way that speed-dependent system non-linearities are compensated for or reduced.

The torque information T _P provided by the functional unit 7.2 is preferably transmitted to a summation point. The summation point adds the values of the moment information T _P with the values of a modified steering disturbance quantity T _LC in order to obtain the disturbance-compensated moment information T _P '.

The modified steering disturbance quantity T _LC is obtained by the functional unit 7.5 based on the steering disturbance quantity T _L . The functional unit 7.5 is designed to multiply the steering disturbance variable T _L by a factor dependent on the vehicle speed information v _ego in order to carry out a proportional, ie speed-dependent, compensation for the disturbance variable.

The disturbance-compensated moment information T _P 'is then preferably supplied to a limiter 7.3. The limiter 7.3 is preferably designed to limit the amplitude and/or the gradient of the disturbance-compensated moment information T _P '. This restriction is made, for example, for security reasons. The limiter 7.3 preferably provides the steering torque information T _M which is then transmitted to the electromechanical steering system 3.

The invention has been described above using exemplary embodiments. It goes without saying that numerous changes and modifications are possible without leaving the scope of protection defined by the patent claims.

reference list

1

system

2

steering angle controller

3

Electric Power Steering

4

steering dynamics model

5

delay element

6

filter unit

7

controller unit

7.1

interference estimator

7.2

functional unit

7.3

limiter

7.4

delay element

7.5

functional unit

Dδ

Model Deviation Information

δC

measured steering angle information

δDP

delayed estimated steering angle information

δE

deviation

δM

modified steering angle information

δP

estimated steering angle information

δR

Steering angle specification

FLat

lateral force

tsp

steering disturbance

TM

steering torque information

TP

moment information

tp'

disturbance-compensated torque information

vegetarian

own speed of the vehicle

Claims (15)

Method for lateral control of a vehicle, the vehicle comprising a steering angle controller (2) and an electromechanical steering (3), a steering dynamics model (4) of the electromechanical steering being implemented in the steering angle controller (2), characterized in that the steering dynamics model is based on a Steering torque information (T _M ) or a variable proportional thereto provides estimated steering angle information (δ _P ), based on the estimated steering angle information (δ _P ) and the measured steering angle (δ _C ) of the electromechanical steering system (3) modified steering angle information (δ _M ) is calculated, and based on the modified steering angle information (δ _M ) and a steering angle specification (δ _R ) a deviation (δ _E ) of the steering angle controller (2) is calculated. procedure after claim 1 , characterized in that the steering dynamics model (4) receives a steering disturbance variable (T _L ) resulting from a lateral force (F _Lat ) applied to the vehicle, the estimated steering angle information (δ _P ) based on the steering torque information (T _M ) or one thereto proportional magnitude and the steering disturbance magnitude (T _L ) is calculated. Method according to one of the preceding claims, characterized in that model deviation information (D _δ ) is calculated based on the estimated steering angle information (δ _P ) and the measured steering angle (δ _C ) of the electromechanical steering system (3), that the model deviation information (D _δ ) is filtered by a filter unit (6) and that based on the filtered model deviation information (P _δ ) and the estimated steering angle information (δ _C ) the modified steering angle information (δ _M ) is generated. procedure after claim 3 , characterized in that the model deviation information (D _δ ) is obtained in that the estimated steering angle information (δ _P ) is delayed by means of a delay element (5) and is subtracted from the measured steering angle (δ _C ) of the electromechanical steering system (3). procedure after claim 3 or 4 , characterized in that the filter unit (6), by means of which the model deviation information (D _δ ) is filtered, has an adjustable amplification factor which can be set adaptively as a function of the driving situation. Method according to one of the preceding claims, characterized in that the steering angle controller (2) has a controller unit (7) with a disturbance estimator (7.1), with the disturbance estimator (7.1) determining the steering disturbance variable (T _L ) based on information which the am lateral force (F _Lat ) acting on the vehicle is estimated. procedure after claim 6 , characterized in that the disturbance estimator (7.1) estimates the steering disturbance variable (T _L ) by means of a Kalman filter. Method according to one of the preceding claims, characterized in that the controller unit (7) has a functional unit (7.2) by means of which a system deviation (δ _E ) resulting from the steering angle specification (δ _R ) and the modified steering angle information (δ _M ) is converted into torque information (T _P ) is converted, the moment information (T _P ) based on the steering disturbance variable (T _L ) or information derived therefrom being converted into disturbance-compensated moment information (T _P '). procedure after claim 8 , characterized in that the disturbance-compensated torque information (T _P ') is converted into the steering torque information (T _M ) by means of a limiter (7.3), the steering torque information (T _M ) being transmitted to the electromechanical steering system (3). System for lateral control of a vehicle, which comprises a steering angle controller (2) and an electromechanical steering system (3), a steering dynamics model (4) of the electromechanical steering system (3) being implemented in the steering angle controller (2), characterized in that the steering dynamics model (4 ) is designed to provide estimated steering angle information (δ _P ) based on steering torque information (T _M ) or a variable proportional thereto, the steering angle controller (2) being designed to do this based on the estimated steering angle information (δ _P ) and the measured steering angle (δ _C ) of the electrome mechanical steering (3) to calculate modified steering angle information (δ _M ) and wherein the steering angle controller (3) is designed to calculate a control deviation (δ _E ) based on the modified steering angle information (δ _M ) and a steering angle specification (δ _R ). system after claim 10 , characterized in that the steering dynamics model (4) is designed to, based on a steering disturbance variable (T _L ), which results from a lateral force (F _Lat ) applied to the vehicle, and the steering torque information (T _M ) or a variable proportional thereto, the estimated Calculate steering angle information (δ _P ). system after claim 10 or 11 , characterized in that the steering angle controller (2) is designed to calculate model deviation information (D _δ ) based on the estimated steering angle information (δ _P ) and the measured steering angle (δ _C ) of the electromechanical steering (3), the model deviation information (D _δ ) by means of a filter unit (6) and based on the filtered model deviation information (F _δ ) and the estimated steering angle information (δ _P ) to generate the modified steering angle information (δ _M ). system after claim 12 , characterized in that the filter unit (6), by means of which the model deviation information D _δ is filtered, has an adjustable amplification factor which can be set adaptively as a function of the driving situation. system according to one of the Claims 10 until 13 , characterized in that the steering angle controller (2) has a controller unit (7) with a disturbance estimator (7.1), the disturbance estimator (7.1) being designed to calculate the steering disturbance variable (T _L ) based on information about the lateral force acting on the vehicle (F _Lat ) indicates to estimate. system after Claim 14 , characterized in that the disturbance estimator (7.1) has a Kalman filter for estimating the steering disturbance variable (T _L ).

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