Method and device for operating a vehicle

Abstract

Method for operating a vehicle, wherein a degree of damage or a state of health of at least one component of a steering system of the vehicle is determined as an estimated variable (SG), characterized in that a steering assistance external to the steering system is generated if at least one damage criterion, which is evaluated as a function of the at least one estimated variable (SG), is met and a steering operation is detected, wherein the steering assistance external to the steering system supports vehicle guidance during the steering operation.

Description

The invention relates to a method and an apparatus for operating a vehicle according to the preamble of claim 1 and according to the preamble of claim 9, respectively.Nowadays, vehicles, in particular automobiles, systems or components, are specified for a predetermined service life (service life). If the actual life or useful life of a component exceeds this specified life, a life-dependent safety measure is initiated. For example, a vehicle driver is requested to replace the component by generating a corresponding output signal.This takes place independently of whether wear up to a relevant damage limit of a component has actually also occurred. Thus, a situation may occur in which the service-life-dependent safety measure is initiated despite a component that is still functional to the desired extent.Furthermore, redundant systems in the vehicle, in particular redundant steering systems, are known. This redundancy may be required, particularly in the case of a steer-by-wire steering system.It is further known that components in the vehicle that no longer have a desired functionality can have undesired effects on operational safety. In particular, components of a steering system that no longer have the desired functionality can adversely affect a steering behavior of the vehicle in an undesired manner.Known from the prior art is US 2023 / 0097944 A1, which describes a method in which a vehicle cannot be accelerated after a speed reduction by a braking intervention of a vehicle driver if a fault has been detected in a steer-by-wire steering system. This document describes various scenarios of such speed regulation.Furthermore, U.S. Pat. No. 10,752,282 B2 is known, which describes a control system in a steering system. The control system includes a first electrical control unit which operates as a primary control unit of the control system and sends an engine control signal to the engine to generate a drive torque. The control system includes a second control unit that serves as a backup for the first control unit. The operation as a backup includes monitoring the first control unit for a malfunction.Furthermore, U.S. Pat. No. 11,605,252 B2 is known, which describes systems and methods for predictive detection of vehicle faults based on diagnostic fault codes. The document describes a method comprising determining a probability of a vehicle fault based on one or more diagnostic fault codes, wherein the probability of the fault is indicated to a vehicle driver if the probability exceeds a threshold value.Furthermore, US 2022 / 0 263 849 A1 is known, which describes abnormality detection in a vehicle network.DE 10 2017 117 327 A1 discloses a steering system of a vehicle showing the preamble and in particular to methods and systems for monitoring vehicle steering systems in order to determine the integrity of the steering system.DE 10 2019 216 934 A1 discloses a method for operating a vehicle, wherein the vehicle comprises a chassis having at least one vehicle wheel and having a steering system, and wherein at least one chassis characteristic variable correlated with the chassis and / or with a wheel guide of the vehicle wheel is adapted in such a way that a steering force and / or wear of at least one vehicle component is reduced, wherein a change in a driving dynamics of the vehicle brought about by the adaptation of the at least one chassis characteristic variable is determined and at least partially compensated by at least one software function, in particular of the steering system.DE 10 2021 125 892 A1 discloses a control device for a vehicle that causes a vehicle to turn automatically, a computer readable medium storing a control program for a vehicle, and a control method for a vehicle.The technical problem arises to provide a method and a device for operating a vehicle which increase operational reliability of the vehicle.The solution of the technical problem is achieved by the subject matters having the features of the independent claims. Further advantageous embodiments of the invention are evident from the dependent claims.A method for operating a vehicle, in particular a motor vehicle, is proposed. The method can also be a method for operating a subsystem of the vehicle, in particular a steering system of the vehicle. Preferably, the vehicle is a motor vehicle or an automobile. However, the method can also serve for operating a vehicle different therefrom.In the method, a degree of damage or a state of health of at least one component of a steering system of the vehicle is determined as an estimated variable. The steering system of the vehicle may include components, in particular mechanical, electrical and / or electronic components, in order to influence vehicle guidance, in particular by a vehicle driver. However, it is also conceivable that a driver assistance system influences the vehicle guidance via the steering system.In steerable wheel vehicles, the steering system may include components to manipulate wheels of the vehicle to a position where the vehicle is then guided along a predetermined trajectory. In automobiles, this can be done, in particular, by setting a steering angle. Alternatively, the steering system may allow other components of the vehicle that are part of a steering system, such as components for adjusting a rudder in aircraft.A steering system may be an electromechanical or hydraulic steering system, in particular an electric power steering system. A steering system can also be a so-called steer-by-wire steering system. Further, a steering system may be a front axle or a rear axle steering system. Such a steering system may comprise an electromechanical or a hydraulic drive device.A steering system can in particular comprise the following mechanical components:steering handle, such as a steering wheel, for example,steering gear, such as a worm gear, for example,- steering column,steering shaft,- steering rack,mechanical connecting means such as screws,valve of a hydraulic power steering system,pump of a hydraulic power steering system,fluid lines of a hydraulic power steering system,driving means of an electromechanical power steering system, such as an electric motor,- torsion bar, and further mechanical components known to the skilled person.A steering system may include the following electrical or electronic components:control device, which can be designed as a computing device and can comprise at least one microcontroller or integrated circuit,steering angle sensor,steering wheel angle sensor,torque sensor,steering shaft position sensor,- steering rack position sensor,electrical contact elements, such as plugs, for example,electrical components, such as electrical switching units, such as MOSFETs or IGBTs,capacitors,- inductances,electrical lines, and further electrical or electronic components known to the skilled person.According to the invention, steering assistance external to the steering system is generated. This will be explained in more detail below. This steering assistance external to the steering system is generated if at least one damage criterion is fulfilled. The damage criterion is evaluated as a function of the at least one degree of damage or the state of health.The degree of damage represents a state and a functionality of the component, in particular on the basis of a predetermined scale or evaluation system. For example, such an evaluation system may comprise a classification into the degrees of damage "A", "B",..., "F", wherein e.g. "A" stands for no damage and "F" stands for severe damage. It is of course also possible to use a numerical value for the representation which lies, for example, between a minimum value, e.g. 0, and a maximum value, e.g. 1, wherein the minimum or maximum value represents no damage and the respectively remaining maximum or minimum value represents a severe damage. The degree of damage can be component-specific.The health condition, which may also be referred to as state of health (SOH), may be a measure of the component in terms of functionality, performance, and / or safety. Analogously to the degree of damage, the state of health can be determined according to a scale or evaluation system, wherein different scale- or evaluation system-specific values represent different states of health. Analogously to the details regarding the degree of damage, a numerical value can be used for the representation, which lies, for example, between a minimum value, e.g. 0, and a maximum value, e.g. 1, wherein the minimum or maximum value represents a maximally healthy state and the respectively remaining maximum or minimum value represents a minimally healthy state. The state of health can also be component-specific.In contrast to the level of damage explained, the state of health generally and as explained above relates to a functionality, performance and / or safety of a component. It describes how good or poor a component can fulfil its intended function and whether it operates safely and efficiently. A good health condition normally means that a component is in an acceptable state, while a poor health condition indicates problems with the component. The degree of damage, on the other hand, refers to a degree of wear, damage and / or deterioration of the component. It describes how much the component is already damaged or worn out. In other words, the state of health is a measure of the general state and the performance of a component, while the degree of damage is a measure of the already occurring wear or damage of a component. It is thus conceivable that a component is in a good state of health but nevertheless has a certain degree of damage.The degree of damage or the state of health can be determined by a computing device of the steering system. For this purpose, at least one input variable can be evaluated, for example a variable detected with the aid of a sensor. Such input variables detected with sensor assistance can be, for example:a temperature of the component,a power or energy consumption of the component,a dynamic variable associated with the component, such as a position, a speed or an acceleration,a pressure,a setpoint variable for controlling / regulating a component, such as a setpoint voltage, a setpoint current, a setpoint torque,an actual variable of the component, such as an actual voltage, an actual current, an actual torque,a command or manipulated variable for a component,a controlled variable of a component, and further variables known to the skilled person, which are component-specific or specific for the operation of the component.In a further embodiment, a setpoint auxiliary torque of a drive device of the steering system and a generated actual auxiliary torque are determined and compared in a steering system, wherein the degree of damage or the state of health of the drive device and / or of the regulating or control device of the drive device can be determined from a difference of these variables.In a further embodiment, an actual auxiliary torque and a change in a steering rack position are detected, wherein the degree of damage or the state of health of the steering gear can be determined as a function of these variables.In a further embodiment, a path or angular range of a movable component, namely the steering rack or a worm wheel, which has already been covered since startup is determined, wherein the degree of damage or the state of health of the steering rack or of the worm wheel or of the steering gear can be determined as a function of the distance covered, for example as a function of a predetermined assignment.Generally, methods and input variables for determining the degree of damage or the state of health of components of a steering system are known to the person skilled in the art.The input variable can be detected with sensor assistance or determined mathematically from a variable detected with sensor assistance.The damage criterion can likewise be evaluated by the computing device of the steering system, a further computing device of the steering system or a computing device different therefrom.The damage criterion can be fulfilled if the degree of damage or the state of health is higher or lower than a predetermined measure. The measure can be selected in such a way that, for example, a relatively higher or lower damage rate or state of health represents an in particular undesirably impaired functionality of the component. An impaired functionality may be a functionality that deviates from the setpoint functionality in the undamaged state. The damage criterion may not be fulfilled if the degree of damage or the state of health is lower or higher than or equal to the predetermined measure, wherein a damage wheel or state of health which is lower or higher in comparison represents a desired functionality of the component. In order to determine whether the damage criterion is fulfilled, a comparison of the estimated variable with a predetermined threshold value can be made, for example.Furthermore, the steering assistance external to the steering system is generated if a steering operation is detected. Thus, two requirements must be fulfilled so that the steering assistance external to the steering system is generated, namely the damage criterion must be fulfilled and a steering process is detected.The steering process can be detected, for example, if an active influence on the vehicle guidance is detected, for example if a vehicle driver actuates a steering handle for active influence on the vehicle guidance. For example, a torque applied to a steering handle by the vehicle driver can be detected and a steering process can be detected as a function thereof. Methods for detecting a steering operation are known to the person skilled in the art.The steering assistance external to the steering system assists a vehicle guidance in the steering operation, in particular the vehicle guidance intended with the steering operation. The intended vehicle guidance can be determined here using methods that are likewise known to the person skilled in the art, for example in the form of a setpoint trajectory. For this purpose, corresponding input variables can likewise be evaluated.Steering assistance external to the steering system denotes influencing of the vehicle by operating components external to the steering system in such a way that the vehicle guidance intended by the detected steering operation is assisted. If, for example, an automobile is to be steered to the left or right, at least one component external to the steering system, such as a brake, can be operated in such a way that the automobile travels to the left or right, respectively, on account of the braking operation. The steering assistance external to the steering system can be provided in such a way that the vehicle guidance intended by the steering operation is achieved completely or only partially by the steering assistance external to the steering system.This advantageously results in the fact that, in the case of at least one component that is not functional as desired, in the steering system of the vehicle, desired vehicle guidance is supported or provided completely by steering assistance external to the steering system and is thus made possible in a safe manner. As a result, the damaged component can be relieved or even completely deactivated, wherein the vehicle can nevertheless be guided in the desired manner. In particular, safe continued operation of the vehicle is made possible at least for a short time without the vehicle having to be immediately shut down. It also advantageously results that a component which is not actually damaged yet but has an undesirably low state of health can be relieved, as a result of which a service life of this component can be extended. Overall, therefore, there is an advantageous increase in the operational safety of the vehicle.By means of the assistance external to the steering system, information can also be advantageously generated for a vehicle driver without risk to the vehicle driver, in particular since an external system is introduced into the steering behavior in a manner that is perceptible and unexpected to the driver. The vehicle driver can in particular perceive this haptically.In a further embodiment, a state of health of the at least one component is determined, wherein the degree of damage is determined as an estimated variable as a function of the state of health. A relationship between the state of health and the degree of damage can be known in advance. Such a relationship can be, for example, a model-based relationship, a characteristic-curve-based relationship or an association-based relationship. By determining the degree of damage as a function of the state of health, it is advantageously the result that the assistance external to the steering system is provided only as a function of damage which is actually present, wherein methods for determining the state of health can, however, also be used to carry out the method. This can in turn reduce the frequency of assistance external to the steering system, which may be irritating to a vehicle occupant.If the steering assistance external to the steering system is provided as a function of a state of health, it advantageously results that a risk of a further deterioration of the state of health of a component which has not yet been adversely affected in an undesired manner can be reduced, which can increase the operational reliability over a longer period of time.It is possible that the degree of damage is determined as a state of health. However, these may also be different from one another and in particular be determined using methods different from one another.In a further embodiment, the estimated variable is determined as a function of at least one variable detected with the aid of a sensor. This and corresponding advantages have already been explained above. The determination can be made here, for example, on a model basis, on a characteristic curve basis or on an assignment basis. Of course, other ways of determination are also possible. A quantity detected with the aid of a sensor can be an input quantity for a method for determining the estimated quantity. Alternatively, it is conceivable that an input variable for such a method is determined from the variable detected with the aid of a sensor, for example by calculation steps. This advantageously results in a reliable determination of a current value of the estimated variable and thus also in a guarantee of operational reliability at the current point in time.In a further embodiment, a component-specific estimated variable of at least two components of the steering system is determined, wherein a damage criterion is evaluated for each component-specific estimated variable, which damage criterion can be, in particular, a component-specific damage criterion. The steering assistance external to the steering system is generated if at least one damage criterion is fulfilled and the steering process is detected. The evaluation of a damage criterion for each component-specific estimated variable can mean that the component-specific estimated variable is determined for each component of a set of selected components and a (component-specific) damage criterion is evaluated as a function of this component-specific estimated variable. The component-specific damage criteria can be different from one another.This advantageously results in different reactions being able to be made to damage various components. If, for example, it is detected that a component which makes only a very small contribution to the vehicle guidance is impaired in its function to a first extent, the component-specific damage criterion cannot be fulfilled, whereas the damage criterion for a component can already be fulfilled at the same extent of impairment if this component makes a higher contribution to the vehicle guidance.In an alternative embodiment, a component-specific estimated variable of at least two components of the steering system is determined, wherein an overall estimated variable is determined as a function of the component-specific estimated variables. The overall estimated variable can be determined in particular as a sum of the component-specific estimated variables, these preferably being weighted with predetermined weighting factors. Of course, however, a different approach to determining the overall estimation variable is also conceivable. The steering assistance external to the steering system is generated if a damage criterion, which is evaluated as a function of the overall estimation variable, is fulfilled and the steering process is detected. This advantageously results in an acceleration and / or reduction of the resources (memory resources and / or computing power resources) required for carrying out the method, since only one damage criterion has to be evaluated.In a further embodiment, the steering assistance external to the steering system is generated by a braking intervention. For this purpose, a brake system of the vehicle can be controlled accordingly, for example. The braking intervention is effected in such a way that the intended vehicle guidance in the steering operation is assisted or completely taken over by the braking operation.As an alternative to generating the steering assistance external to the steering system by a brake intervention, this may also be generated by another vehicle system, for example by a drive system of the vehicle. For example, a vehicle guidance can be influenced by applying / operating drive torques different from one another to driven wheels of an automobile at least temporarily.Of course, other systems for generating the steering assistance external to the steering system are also conceivable. However, the provision of steering support external to the steering system by a brake grip advantageously results in simple and reliable support or effect of vehicle guidance during the steering process.In a further embodiment, an amount of assistance is set depending on the at least one estimated variable. If, for example, a second estimated variable represents a higher impairment of the component than a first estimated variable, the amount of assistance in the case that the second estimated variable is determined for the component can be greater than the amount of assistance in the case that the first estimated variable is determined for the component. It is also conceivable that, when determining the estimated variable as a second estimated variable, the vehicle guidance takes place completely on the basis of the steering assistance external to the steering system, wherein, when determining the estimated variable as a first estimated variable, the vehicle guidance takes place only partially by the steering assistance external to the steering system. This advantageously results in a further improvement in operating safety, since it is possible to react variably to different degrees of damage.In a further embodiment, the estimated variable is determined in each case by at least two computing devices different from one another, in particular of the steering system, wherein a plausibility criterion is evaluated as a function of the at least two estimated variables, wherein the steering assistance external to the steering system is generated if the plausibility criterion is additionally fulfilled.The two computing devices can be two computing devices of a control unit. The computing devices can be control devices for generating control signals for the operation of the steering system, in particular for the operation of a drive device of the steering system. In this case, it is possible for a first computing device to serve as the main computing device and the at least one further computing device to serve as the backup computing device, wherein in a fault-free state of the main computing device this main computing device generates the control signals. In an error-free state of this main computing device, the backup computing device can generate the control signals or take over the generation of the control command. The computing devices can be connected by data or signals, e.g. via a vehicle communication system such as a bus system or via a communication interface such as an inter-micro communication interface.The plausibility criterion can be evaluated by the main computing device or the backup computing device. Thus, the plausibility criterion can be fulfilled, for example, when the estimated variables do not deviate from one another or do not deviate from one another by more than a predetermined amount. The plausibility criterion cannot be fulfilled if the two estimated variables deviate from one another by more than a predetermined amount.It is possible for the two computing devices to determine the estimated variables in the same way or else in a manner different from one another.If the plausibility criterion is not fulfilled, a warning signal can be generated for a vehicle driver. However, no steering assistance external to the steering system is generated in this case, since it cannot be assumed with sufficient certainty that the estimated variables are correctly determined on the basis of the plausibility criterion which is not fulfilled. This advantageously results in a further improvement in operating reliability.Furthermore, a device for operating a vehicle, in particular a steering system of the vehicle, is proposed. The apparatus comprises at least one first computing device and at least one control device. The first computing device and the at least one control device can in this case comprise at least one microcontroller or an integrated circuit or be designed as such(s). It is possible that the first computing device forms the control device. However, these may also be devices different from each other. The computing device determines a degree of damage or a state of health of at least one component of the steering system as an estimated variable.According to the invention, the control device initiates generation of steering assistance external to the steering system if at least one damage criterion, which is evaluated as a function of the estimated variable, is fulfilled and a steering process is detected. The steering assistance external to the steering system assists or completely adopts vehicle guidance in the steering operation. It is possible for the computing device or the control device to evaluate the damage criterion. Furthermore, the computing device, the control device or a device different therefrom can detect the steering operation. Also, in this manner, vehicle guidance intended by the steering operation can be determined. The device is thus configured such that a method according to one of the embodiments described in this disclosure can be carried out with the device. The proposed device thus advantageously enables a method for operating the vehicle to be carried out with increased operational reliability.In a further embodiment, the apparatus comprises at least one further computing device, wherein the further computing device is different from the first computing device. As explained above, the first computing device can be a main computing device and the further computing device can be a backup computing device. The estimated variable is determined in each case by the at least two computing devices, wherein a plausibility criterion is evaluated as a function of the at least two estimated variables determined in this way, wherein the control device initiates generation of the steering assistance external to the steering system if the plausibility criterion is additionally fulfilled. This and corresponding advantages have already been explained above.A vehicle having such a device is also described.The invention is explained in more detail below with reference to preferred embodiments. The figures show: FIG. 1 shows a schematic flow diagram of a method according to the invention, FIG. 2 shows a schematic flow diagram of a method according to the invention in a further embodiment, FIG. 3 shows a schematic flow diagram of a method according to the invention in a further embodiment, FIG. 4 is a schematic block diagram of an apparatus according to the invention; and FIG. 5 shows a schematic block diagram of a device according to the invention in a further embodiment.In the following, the same reference numerals denote elements having the same or similar technical features.FIG. 1 shows a schematic flow diagram of a method according to the invention for operating a vehicle. In a first step S 1, an estimation variable SG of at least one component of a steering system of the vehicle is determined. Exemplary components of the steering system have already been explained above. As the estimated variable SG, a degree of damage or a state of health of the at least one component can be determined using a method known to the person skilled in the art.In a second step S 2, a damage criterion is checked, which is evaluated as a function of the at least one estimated variable SG. If the damage criterion is not fulfilled, the method returns to the first step S 1. If the damage criterion is fulfilled, a check is made in a third step S 3 as to whether a steering operation is initiated or is carried out. If this is not the case, the method can carry out this step S 3 again, in particular after a predetermined period of time has elapsed. If it is detected that a steering operation is initiated or carried out, then in a fourth step S 4 a vehicle guidance intended by the steering operation is assisted by steering assistance external to the steering system. The intended vehicle guidance can likewise be determined here before assistance by the steering assistance external to the steering system. The steering assistance external to the steering system can be generated in particular by a braking intervention.It is possible that in the first step S 1 firstly a state of health of the at least one component is determined, wherein then a degree of damage is determined as an estimated variable SG as a function of the state of health. The degree of damage or the state of health can be determined as a function of at least one variable detected with sensor assistance, wherein this is used directly or only indirectly for the determination.Furthermore, it is possible that the level of support in the fourth step S 4 is selected depending on the at least one estimation variable SG, in particular depending on its level.FIG. 2 shows a schematic flow diagram of a method according to the invention in a further embodiment. A first step S 1 ais illustrated, in which a component-specific estimation variable SGa of a first component of the steering system is determined. In a second step S 2 a, a component-specific damage criterion for this first component is evaluated as a function of this component-specific estimated variable SGa. If this damage criterion is fulfilled, the method is continued with a third step S 3, which corresponds to the third step S 3 shown in FIG. 1. If the damage criterion for the first component is not fulfilled, then in a further first step S 1 b, a component-specific estimated variable SGb for a further component of the steering system is determined, wherein in a further second step S 2 b, a component-specific damage criterion for this further component is evaluated as a function of this component-specific estimated variable SGb. If this damage criterion is fulfilled, the method is continued with the third step S 3, as explained. If this further criterion is not fulfilled, component-specific estimated variables for further components and damage criteria are determined or evaluated. FIG. 2 shows that a steering system comprises n components for which in each case a component-specific estimated variable SGn can be determined, wherein in a further first step S 1 n this nth component-specific estimated variable SGn is determined and in a further second step S 2 n a further damage criterion, which is specific for this nth component, is evaluated as a function of this estimated variable SGn. If this is also not fulfilled, the method returns to the first step S 1. If the further component-specific damage criterion for the nth component is fulfilled, the method is continued with the third step S 3. In particular, in this third step S 3 it is detected whether a steering operation is initiated or carried out, wherein in a fourth step S 4 a vehicle guidance intended in the steering operation is then assisted by steering assistance external to the steering system.FIG. 3 shows a schematic flow diagram of a method according to the invention in a further embodiment. It is shown that for n-components of a steering system of the vehicle, a component-specific estimation variable SGa, SGb,..., SGn is determined in first steps S 1 a, S 1 b,..., S 1 n, respectively. Then, in a determination step, a total estimation variable SGr is determined as a function of these component-specific estimation variables SGa, SGb,..., SGn. In a second step S 2, a damage criterion, which is evaluated as a function of the overall estimation variable SGr, is then checked, and if this is fulfilled, the method continues with the third and fourth steps S 3, S 4 already illustrated in connection with FIGS. 1 and 2.FIG. 4 shows a schematic block diagram of an apparatus 1 for operating a vehicle, the apparatus 1 comprising a first computing device 2 and a control device 3. The computing device 2 determines a degree of damage or a state of health of at least one component of the steering system as the estimated variable SG.For this purpose, the computing device can evaluate input variables which are transmitted to the computing device 2, for example, via a vehicle communication network. Such input variables can be, in particular, variables recorded with sensor assistance or variables calculated from variables recorded with sensor assistance. Illustrated by way of example are m input variables E 1, E 2,..., Em, which can represent, for example, a temperature value, a current value, a torque value or further values.Furthermore, the computing device 2 can check the at least one damage criterion, which is evaluated as a function of the at least one estimated variable SG, and also detect whether a steering operation is present or is initiated. If the damage criterion is fulfilled and if such a steering operation is detected, the computing device 2 can transmit a corresponding signal to the control device 3, wherein the latter then generates a control signal S for generating the steering assistance external to the steering system.FIG. 5 shows a schematic block diagram of a device 1 according to the invention in a further embodiment. It is shown that the apparatus 1 comprises a first computing device 2 a, which can also be referred to as a main computing device, and a second computing device 2 b, which can also be referred to as a backup computing device. These computing devices 2 a, 2 bmay be part of a common control unit independently of one another, i.e. in particular be arranged within the housing of this control unit. It is shown that the two computing devices 2 a, 2 bin each case receive the same input variables E 1, E 2,..., Em. It is further shown that both computing devices each independently determine a component-specific estimated variable SG. Via an inter-micro communication interface 4, the estimation variable SG determined by the second computing device 2 acan be transmitted to the first computing device 2 a. There, in a step SP, a plausibility criterion is evaluated as a function of the at least two estimation variables SG. The control device 3 is only caused to generate a control signal S for generating the steering assistance external to the steering system if this plausibility criterion is fulfilled.List of reference characters1 Device for operating a vehicle 2 first computing device 2 afirst computing device 2 bsecond computing device 3 control device 4 inter-micro communication interface S 1 first step S 2 second step S 3 third step S 4 fourth step S 1 a, S 1 b,..., S 1 nfirst steps S 2 a, S 2 b,..., S 2 nsecond steps SG schätz variable SGa, SGb,..., SGn component-specific estimation variable SGr resulting estimation variable E 1 first input variable E 2 second input variable Em m-th input variable SP plausibility checking step

Claims

Method for operating a vehicle, wherein a degree of damage or a state of health of at least one component of a steering system of the vehicle is determined as the estimated variable (SG), characterized in that steering assistance external to the steering system is generated if at least one damage criterion, which is evaluated as a function of the at least one estimated variable (SG), is fulfilled and a steering operation is detected, wherein guidance of the vehicle in the steering operation is assisted by the steering assistance external to the steering system.Method according to Claim 1, characterized in that the state of health of the at least one component is determined, the degree of damage being determined as an estimated variable (SG) as a function of the state of health.Method according to Claim 2, characterized in that the estimated variable (SG) is determined as a function of at least one variable detected with the aid of a sensor.Method according to one of the preceding claims, characterized in that a component-specific estimation variable (SGa, SGb,..., SGn) of at least two components of the steering system is determined, wherein a damage criterion is evaluated for each component-specific estimation variable (SGa, SGb,..., SGn), wherein the steering assistance external to the steering system is generated if at least one damage criterion is fulfilled and the steering operation is detected or in that a component-specific estimation variable (SGa, SGb,..., SGn) of at least two components of the steering system is determined, wherein a total estimation variable (SGr) is determined as a function of the component-specific estimation variables (SGa, SGb,..., SGn), wherein the steering assistance external to the steering system is generated if a damage criterion, which is evaluated as a function of the overall estimated variable (SGr), is fulfilled and the steering process is detected.Method according to one of the preceding claims, characterized in that a setpoint auxiliary torque of a drive device of the steering system and a generated actual auxiliary torque are determined and compared, wherein the degree of damage or the state of health of a drive device and / or of the regulating or control device (3) of the drive device is determined from a difference of these variables and / or an actual auxiliary torque and a change in a steering rack position are detected, wherein the degree of damage or the state of health of a steering gear is determined as a function of these variables and / or a path or angle range of a steering rack or of a worm wheel already covered since start-up is determined, wherein the degree of damage or the state of health of the steering rack or of the worm wheel is determined as a function of the distance covered.Method according to one of the preceding claims, characterized in that the steering assistance external to the steering system is generated by a braking intervention.Method according to one of the preceding claims, characterized in that a height of the steering assistance is set as a function of the at least one estimated variable (SG).Method according to one of the preceding claims, characterized in that the estimated variable (SG) is determined in each case by at least two mutually different arithmetic devices (2a, 2b), wherein a plausibility criterion is evaluated as a function of the at least two estimated variables (SG), wherein the steering assistance external to the steering system is generated if the plausibility criterion is additionally fulfilled.Device for operating a vehicle, wherein the device (1) comprises at least one computing device (2a) and at least one control device (3), wherein a degree of damage or a state of health of at least one component of the steering system is determined as an estimated variable (SG) by the computing device (2a), characterized in that generation of steering assistance external to the steering system is initiated by the control device (3) if at least one damage criterion, which is evaluated as a function of the estimated variable (SG), is fulfilled and a steering process is detected, wherein guidance of the vehicle in the steering process is assisted by the steering assistance external to the steering system.Device according to Claim 9, characterized in that the device (1) comprises at least one further computing device (2b), wherein the further computing device (2b) is different from the first computing device (2a), wherein the estimated variable (SG) is determined in each case by the at least two computing devices (2a, 2b), wherein a plausibility criterion is evaluated as a function of the at least two estimated variables (SG), wherein the control device (3) initiates generation of the steering assistance external to the steering system if the plausibility criterion is additionally fulfilled.

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