Method for monitoring a steering system

Abstract

The invention relates to a method for monitoring a steering system (10), in particular during operation in a vehicle (12), wherein a load characteristic variable of at least one steering member (14) of the steering system (10) is determined and evaluated for determining a load and / or a state of the steering member (14), and wherein the load characteristic variable comprises at least one load of the steering member (14) caused by an external force action. It is proposed that, in order to determine the load caused by the external force action, at least one movement of a steering handle (24) of the steering system (10) is monitored.

Description

Technical Field

[0001] This invention relates to a method for monitoring a steering system according to the invention. The invention also relates to a controller having a computing unit for performing this method and a vehicle having such a controller. Background Technology

[0002] DE 10 2004 017 660 A1 discloses a method for monitoring electrical and / or electromechanical systems, such as steering systems, wherein load characteristic parameters are obtained and evaluated in the form of internal or system-specific loads of the component to determine the load and / or state of the component. Furthermore, other system parameters, such as operating duration, load duration, and / or ambient temperature, may be considered in the evaluation. However, external loads (which also have a significant impact on the load and / or state of the component, and are caused, for example, by uneven roads, potholes, and / or other special events) are not considered here. Summary of the Invention

[0003] Therefore, the object of the present invention is, in particular, to provide a method for monitoring a steering system, which has improved characteristics in terms of load analysis. This object is achieved through the features of the present invention.

[0004] The present invention is based on a method for monitoring a steering system, particularly during operation in a vehicle and advantageously in a motor vehicle, wherein a load characteristic parameter of at least one steering component of the steering system, particularly a steering member to be monitored, is obtained and evaluated to determine the load and / or condition of the steering component, particularly mechanical and / or electrical, and wherein the load characteristic parameter includes at least one load of the steering component caused by external forces and particularly by environmental forces acting on the steering component, particularly external.

[0005] The invention proposes monitoring and, in particular, evaluating at least one movement of the steering handle of the steering system to determine the load caused by external forces. These external forces, in particular, may be caused by, for example, uneven roads, potholes, collisions with obstacles, steering through obstacles, causing obstacles while driving over obstacles, and / or other such specific events. These external forces are advantageously different from the direct action of steering motion and / or force on the steering handle, especially by the driver. Furthermore, by evaluating load characteristic parameters, the load and / or condition of components acting in connection with the steering system (e.g., steering tie rods and / or chassis) can also be determined. This design approach allows for advantageous load analysis of steering components, the steering system, and / or components acting in connection with the steering system. In particular, it allows for the systematic detection and consideration of damage mechanisms from external loads, which can be significantly different from damage mechanisms from internal and / or system-specific loads, thereby advantageously improving operational reliability. Furthermore, the remaining service life and / or probability of failure of components can be advantageously determined using the load and / or condition of the monitored components. Furthermore, by monitoring the movement of the steering handle, the load in the sensor system of the steering shaft and / or steering system can be advantageously and easily determined.

[0006] In particular, the steering system includes a steering handle and at least one steering member. Furthermore, the vehicle and / or steering system may include other components and / or assemblies, such as a steering transmission mechanism, which advantageously has at least one steering adjustment element, in the form of a rack, including a steering shaft for mechanically connecting the steering handle, particularly to the steering transmission mechanism, including at least one steering actuator, particularly acting in conjunction with the steering transmission mechanism, including at least one transmission mechanism for coupling the steering actuator to the steering transmission mechanism, including at least one detection unit for detecting load characteristic parameters, including at least one steering sensor operatively connected to the steering shaft for detecting steering bar signals, and / or at least one controller. In particular, the steering shaft and / or the component directly operatively connected to the steering shaft may be the steering member to be monitored. In this document, "steering actuator" should be understood in particular as an actuator unit, especially one with an electrical configuration, particularly configured to transmit steering torque to the steering adjustment element and thereby advantageously influence the vehicle's direction of travel. Preferably, the steering actuator is configured to provide steering torque to support the manual torque applied to the steering handle and / or to provide steering torque for automatic and / or autonomous control of the vehicle's direction of travel. Therefore, the steering actuator may include at least one electric motor. "Setting up" should be understood in particular as specifically programmed, designed, and / or equipped. "Object setting for a specific function" should be understood in particular as the object satisfying and / or implementing that specific function in at least one application and / or operating state.

[0007] Furthermore, "load characteristic parameter" should be understood in particular as a characteristic parameter related to the load on the steering component, at least as caused by the action of internal and / or external forces acting on it. Specifically, at least by means of the load characteristic parameter, the load and / or condition of the steering component, particularly mechanical and / or electrical, can be inferred and / or determined. If the load characteristic parameter can also be calculated using, particularly, the actual and, for example, pre-determined load capacity of one of the components, particularly the steering component, the steering system, and / or components acting in connection with the steering system, then it is advantageous to directly state information about the remaining service life. Preferably, the load characteristic parameter is monitored throughout the entire monitoring interval, and the change of the load characteristic parameter over time is evaluated to determine the load and / or condition of the steering component. "Monitoring interval" should be understood in particular as a time interval, particularly longer in duration and advantageously related to the service life of the steering system and / or the vehicle, during which changes in the load characteristic parameter are detected. In particular, the monitoring interval can include periods of days, weeks, months, and / or years.

[0008] Furthermore, the vehicle and / or steering system may particularly include at least one computing unit and / or at least one controller having a computing unit, wherein the computing unit is particularly configured to implement methods for monitoring the steering system. "Computing unit" should be understood in particular as an electrical and / or electronic unit having information input, information processing, and information output. The computing unit also advantageously has at least one processor, at least one operating memory, at least one input and / or output device, at least one operating program, at least one control routine, at least one calculation routine, at least one monitoring routine, and / or at least one evaluation program. In particular, the computing unit is at least configured to obtain and / or receive load characteristic parameters of the steering components and evaluate them, particularly for determining the load and / or state of the steering components, especially mechanical and / or electrical loads. Furthermore, the computing unit is particularly configured to monitor at least one movement of the steering handle to obtain the load caused by external forces.

[0009] It is also proposed to use at least one motion sensor for monitoring the movement of the steering handle. The motion sensor is specifically configured to detect motion signals related to the movement of the steering handle and can be configured, for example, as a speed sensor, an acceleration sensor, and / or a solid-state noise sensor. This allows for particularly simple and / or inexpensive acquisition of external loads.

[0010] Furthermore, the motion sensor is advantageously different from the steering sensor used to detect the steering bar signal and is specifically arranged in a region of the steering system different from that of the steering sensor. Preferably, the motion sensor has an extended detection range, and in particular an extended measurement range, compared to the steering sensor. Specifically, the steering sensor has a first detection range and the motion sensor has a second detection range extended compared to the first detection range. Furthermore, the external force is preferably related to dynamic driving maneuvers and results in a torque higher than the threshold detected by the steering sensor and detectable only by means of the motion sensor. The "area of ​​the object" should be understood in particular as a spatial region extending around the object and consisting of points at most 30 cm, preferably at most 20 cm, and particularly preferably at most 10 cm from the object's reference point and / or reference member. This allows for the detection of harmful external loads located above the detection range of the steering sensor.

[0011] Furthermore, it is proposed to arrange the motion sensor in the area of ​​the steering handle, or particularly in the area of ​​the peripheral components of the steering handle that have dominant inertia. When the steering handle is constructed as a steering wheel, the steering handle, especially the component with dominant inertia, makes it advantageous to arrange the motion sensor in the area of ​​the steering handle. However, if the steering handle is constructed as a lever, steering column, or steering ball, the component with dominant inertia may differ from the steering handle and may correspond to the peripheral components of the steering handle, such as a feedback actuator that works in conjunction with the steering handle, for example, in the form of an electric motor or flywheel. In this case, the motion sensor is preferably arranged in the area of ​​the peripheral components. This allows for advantageously simple and accurate detection of external forces.

[0012] A motion sensor can be configured as an accelerometer and set to detect acceleration signals related to the movement of the steering handle. However, according to a preferred design, in order to monitor the movement of the steering handle by means of a motion sensor, a motion signal, which is related to the deflection and / or speed of the steering handle and is different from the acceleration signal, is detected, and in order to obtain the load caused by external forces from the motion signal, the acceleration signal, in particular, related to the movement of the steering handle, is calculated. The acceleration signal is preferably calculated here using gradient forming, and particularly preferably using a difference quotient. This, in particular, minimizes the delay in the motion signal.

[0013] Furthermore, it is proposed that when determining the load caused by external forces, at least one inertia and an advantageous moment of inertia of the steering handle and / or, in particular, the peripheral components of the steering handle with dominant inertia should be taken into account. When the steering handle is constructed as a steering wheel, the steering handle is particularly a component with dominant inertia, thus advantageously taking into account at least one inertia of the steering handle when determining the load caused by external forces. However, if the steering handle is constructed as a lever, steering rod, or steering ball, the component with dominant inertia may differ from the steering handle and may correspond to the peripheral components of the steering handle, such as a feedback actuator acting in conjunction with the steering handle, for example, in the form of an electric motor or flywheel. In this case, at least one inertia of the peripheral components should be taken into account when determining the load caused by external forces. Therefore, when determining the load caused by external forces, the design-specific inertia of the steering system in the area of ​​the steering handle can be advantageously considered.

[0014] Furthermore, it is proposed that, in order to determine the load caused by external forces, at least one operating parameter of the electrical steering actuator of the steering system, particularly the steering actuator already mentioned, and advantageously the rotor element of the steering actuator, is monitored and, in particular, evaluated. This advantageously and simply allows for the determination of the load in the steering transmission mechanism and / or the servo system of the steering system. The operating parameter here is preferably the acceleration of the steering actuator, particularly caused by external forces, and / or acceleration-related operating parameters, such as the operating voltage and / or operating current of the steering actuator. Furthermore, it is advantageous to consider the inertia and, advantageously, the moment of inertia of at least one of the electrical steering actuator and, advantageously, the rotor element of the steering actuator, for determining the load caused by external forces. Moreover, it is proposed that, in order to determine the load caused by external forces, the operating parameters of the steering actuator be correlated with and / or combined with the movement of the steering handle into a common evaluation dataset. This, in particular, allows for a particularly accurate determination of the external load.

[0015] In another design scheme, it is proposed that the load characteristic parameters include at least one internal and / or system-specific load generated, particularly during the operation of the steering system, and acting on the steering components. This allows for a comprehensive load analysis of the steering components and / or the steering system. Consequently, damage mechanisms from internal and / or system-specific loads can be detected and considered, thereby advantageously further improving operational reliability.

[0016] To determine internal and / or system-specific loads, vehicle and / or steering systems may include specialized sensors, such as voltage sensors, current sensors, and / or temperature sensors. However, alternatively or additionally, it is proposed that, to determine internal and / or system-specific loads, at least one driving torque and / or driving force of the steering actuator, and / or other operating parameters related to the driving torque and / or driving force, such as other operating voltages and / or other operating currents, be monitored and, in particular, evaluated from the rotor element of the steering actuator. This allows for a particularly simple and / or cost-effective determination of internal and / or system-specific loads.

[0017] If load characteristic parameters are also used to determine the rack force, the functionality of the steering system can be advantageously further enhanced. In this case, the load characteristic parameters advantageously include the particularly external loads on the steering components caused by external forces, especially those acted upon by the environment, as well as the internal and / or system-specific loads on the steering components, particularly those generated during the operation of the steering system and acting upon them. Furthermore, in this case, the movement of the steering handle and the operating parameters of the electric steering actuator are preferably monitored and, in particular, evaluated to determine the loads caused by external forces.

[0018] If a favorable combination Using rainflow counting to evaluate load characteristic parameters, such as the Haigh diagram, Haigh diagram, and / or Miner rule, can provide a particularly simple evaluation algorithm for load analysis, which also allows for the determination of the remaining operating duration of steering components.

[0019] The methods for monitoring steering systems, controllers, and vehicles are not limited to the applications and implementations described above. In particular, to achieve the functions described herein, the methods for monitoring steering systems, controllers, and vehicles may have a number of individual elements, components, and units different from those described herein.

[0020] Other advantages will become apparent from the following description of the accompanying drawings, which illustrate one embodiment of the invention. Those skilled in the art will also readily consider these aspects individually and combine them into further meaningful combinations. Attached Figure Description

[0021] Figure 1a -b illustrates an exemplary vehicle with a steering system in a simplified diagram, and

[0022] Figure 2 A schematic diagram of the signal flow for monitoring the steering system is shown. Detailed Implementation

[0023] Figure 1a and Figure 1bA simplified illustration shows an exemplary vehicle 12 configured as a passenger car, having multiple wheels 22 and a steering system 10. The steering system 10 is operatively connected to the wheels 22, which are currently configured particularly as front wheels, and is configured to influence the driving direction of the vehicle 12. Furthermore, the steering system 10 is configured as an electrically supported steering system and therefore has an electrically assisted force support device in the form of a servo steering device. Additionally, the vehicle 12 currently includes, for example, at least two different driving modes, particularly a conventional and / or manual driving mode and an autonomous and / or partially autonomous driving mode. However, it is also conceivable in principle to configure the steering system as a hydraulically supported steering system, particularly with a hydraulically assisted force support device. Furthermore, the vehicle may have exactly one driving mode.

[0024] The steering system 10 includes a steering handle 24, exemplarily configured as a steering wheel in this case, for applying manual torque; a steering transmission mechanism 26, exemplarily configured as a rack and pinion steering mechanism, which includes a steering adjustment element 30 and is configured to convert the steering of the steering handle 24 into steering motion of the wheel 22; and includes a steering shaft 28 for mechanically connecting the steering handle 24 to the steering transmission mechanism 26. The steering transmission mechanism 26 defines the servo system of the steering system 10. The steering shaft 28 defines the sensor system of the steering system 10. Alternatively, the steering handle may also be configured as a steering rod or a steering ball, etc.

[0025] Furthermore, the steering system 10 includes a steering actuator 16. The steering actuator 16 is at least partially electrically and / or electronically configured. The steering actuator 16 is operatively connected to the steering transmission mechanism 26. The steering actuator 16 is configured to provide steering torque to support the hand torque applied to the steering handle 24 and transmit it to the steering adjustment element 30. For this purpose, the steering actuator 16 includes at least one electric motor. In the present case, the electric motor is particularly configured as a permanent magnet synchronous motor and configured to generate steering torque. In principle, the steering actuator may also include multiple electric motors.

[0026] Furthermore, the steering system 10 includes at least one steering sensor 34, which is arranged on the steering shaft 28 and is known in itself. The steering sensor 34 is configured as a torque sensor. The steering sensor 34 is configured to detect steering information related to the operation of the steering handle 14, particularly the hand torque and / or torque applied to the steering handle 14. In the present case, the steering sensor 34 is configured to detect the steering bar signal. The maximum detection range of the steering sensor 34 is here between -10 Nm and +10 Nm. Alternatively, the steering sensor may also be configured as a sensor other than a torque sensor, such as a rotation angle sensor and / or a combination of torque and rotation angle sensors.

[0027] The steering system 10 also includes at least one operation sensor 36 assigned to the steering actuator 16. The operation sensor 36 is configured as a rotor position sensor and is configured to detect at least one operation measurement of the steering actuator 16, in the present case, particularly the rotor position signal of the electric motor. However, alternatively or additionally, the operation sensor may also be configured as a sensor other than the rotor position sensor, such as an acceleration sensor, a solid-state noise sensor, a voltage sensor, a current sensor, and / or as a temperature sensor.

[0028] Furthermore, the steering system 10 includes at least one motion sensor 32. The motion sensor 32 differs from the steering sensor 34 and the running sensor 36. The motion sensor 32 is configured as a speed sensor. The motion sensor 32 is configured as a steering wheel sensor. Compared to the steering sensor 34, the motion sensor 32 has an extended detection range. In the present case, the motion sensor 32 is designed to detect torques less than -10 Nm and / or greater than +10 Nm. The motion sensor 32 is also arranged in the area of ​​the steering handle 24. The motion sensor 32 is configured to detect motion signals associated with the movement of the steering handle 24, particularly speed signals in the present case. However, alternatively, the motion sensor can also be configured as a sensor different from the speed sensor, such as a position sensor, distance sensor, acceleration sensor, and / or solid-state noise sensor, and is particularly configured to detect motion signals different from speed signals. Furthermore, the motion sensor can also, in principle, be arranged in the area of ​​the steering shaft, advantageously above the steering intermediate shaft. Additionally, it is conceivable to arrange the motion sensor in the area of ​​the peripheral components of the steering handle, especially if the steering handle is configured differently from the steering wheel.

[0029] Furthermore, vehicle 12 has a controller 18. The controller 18 is exemplarily configured as a steering controller and is therefore part of the steering system 10. The controller 18 has an electrical connection to the steering actuator 16. Additionally, the controller 18 is electrically connected to a motion sensor 32, a steering sensor 34, and a running sensor 36. The controller 18 is configured to receive motion signals from the motion sensor 32, a steering bar signal from the steering sensor 34, and running parameters from the running sensor 36. Furthermore, the controller 18 is configured to operate the steering actuator 16.

[0030] For this purpose, the controller 18 includes a computing unit 20. The computing unit 20 includes at least one processor, for example in the form of a microprocessor, and at least one runtime memory. Furthermore, the computing unit 20 includes at least one runtime program stored in the runtime memory, having at least one monitoring routine 38, at least one calculation routine, and, in the current case, particularly damage calculation routines 40 and 44, and at least one evaluation routine 50. However, in principle, it is also conceivable to construct the controller separately from the steering system. In this case, the vehicle could have, for example, a single central controller with a central computing unit.

[0031] To improve the analysis of the load and / or condition of the steering system 10 or at least one steering member 14 of the steering system 10, a method for monitoring the steering system 10 is proposed in the present context. In the present context, the steering member 14 exemplarily corresponds to the steering shaft 28 or at least a portion of the steering shaft 28. Alternatively or additionally, the steering member to be monitored may also be a steering transmission mechanism, a steering actuator, and / or a clutch transmission mechanism for coupling the steering actuator to the steering transmission mechanism or a portion thereof. Furthermore, the load and / or condition of components operatively connected to the steering system, such as the steering tie rod and / or the chassis, may also be monitored.

[0032] Furthermore, the computing unit 20 is specifically provided with a computer program for implementing the method and for this purpose has a corresponding program code device.

[0033] In the present case, the load characteristic parameters of the steering component 14 to be monitored are obtained and evaluated to determine, in particular, the mechanical load and / or condition of the steering component 14. In the present case, the load characteristic parameters are monitored throughout the entire monitoring interval, advantageously throughout the entire operating duration and / or service life of the steering system 10 and / or the vehicle 12, and the changes in the load characteristic parameters over time are evaluated to determine the load and / or condition of the steering component 14.

[0034] The load characteristic parameters include at least one external load on the steering member 14 caused by external forces, particularly by environmental forces acting on the steering member 14. Specifically, the external forces causing the load on the steering member 14 can, for example, arise from uneven roads, potholes, collisions with obstacles, steering over obstacles, overtaking obstacles, and / or other such specific events. The load caused by external forces consists primarily of at least two main components: the load in the steering shaft 28 and / or the sensor system, and the load in the steering transmission mechanism 26 and / or the servo system.

[0035] To determine the load caused by external forces, particularly the load in the steering shaft 28 and / or the sensor system, in the present case, at least one motion of the steering handle 24 caused by an external force and detected by means of the motion sensor 32 is monitored and evaluated. For this purpose, a motion signal related to the motion speed of the steering handle 24 and but different from an acceleration signal is detected by the motion sensor 32, and then an acceleration signal related to the motion of the steering handle 24 is calculated from this motion signal. The acceleration signal is calculated here using gradient forming, and particularly when using difference quotients. However, alternatively, another type of differential calculation can be used, or the acceleration signal related to the motion of the steering handle can be directly detected. Furthermore, the inertia of the steering handle 24 is taken into account when determining the load caused by external forces. In this case, the following applies to external loads, particularly those in the steering shaft 28 and / or the sensor system:

[0036]

[0037] Here J1 describes the inertia of the steering handle 24 and The acceleration of the steering handle 24 is described, particularly in the form of angular acceleration. The rotation bar signal from the steering sensor 34 is not considered for determining the load caused by external forces, because the resulting torque is significantly greater than the torque that can be determined using the steering sensor 34.

[0038] Additionally, to determine the load caused by external forces, particularly the load in the steering transmission mechanism 26 and / or the servo system, operating parameters caused by external forces and detected by means of the operating sensor 36 in the form of acceleration of the steering actuator 16 are monitored and evaluated, where the inertia of the steering actuator 16 can also be taken into account. In this case, the following applies to external loads, particularly in the steering transmission mechanism 26 and / or the servo system:

[0039]

[0040] Here J2 describes the inertia of the steering actuator 16. The acceleration of the steering actuator 16, particularly the rotor acceleration, is described, and η describes the gear ratio of the clutch transmission mechanism used to couple the steering actuator 16 to the steering transmission mechanism 26. ext It describes the efficiency of external loads.

[0041] To improve the determination of the load and / or state of the steering component 14, the operating parameters of the steering actuator 16 can be correlated with and / or merged with the motion of the steering handle 24 into a common evaluation dataset.

[0042] The total external load is thus determined as follows:

[0043]

[0044] However, in principle, under the current circumstances, it is also possible to omit monitoring the steering actuator and thus omit determining the load in the steering transmission mechanism or servo system.

[0045] To further enable a comprehensive load analysis of the steering component 14 and / or the steering system 10, the load characteristic parameters also include internal and / or system-specific loads on the steering component 14, particularly those generated during the operation of the steering system 10 and acting on the steering component 14. These internal and / or system-specific loads are caused by the normal operation of the steering system 10. To determine these internal and / or system-specific loads, the driving torque and / or driving force of the steering actuator 16 can be monitored and evaluated, for example. In this case, the following applies to the internal and / or system-specific loads:

[0046] M int =M el ·i·η int (4).

[0047] Here M el The driving torque and / or driving force of the steering actuator 16 are described, i describes the gear ratio of the clutch transmission mechanism, and η int It describes the efficiency of internal and / or system-specific loads.

[0048] The load characteristic parameter or total load of the steering component 14 is then composed of external loads and internal and / or system-specific loads of the steering component 14, wherein the case where the external load is greater than the internal and / or system-specific load indicates an external special event, such as a pothole, collision with an obstacle, etc. However, in principle, it is also possible to omit the detection and / or evaluation of the internal and / or system-specific loads of the steering component and to map such internal and / or system-specific loads, for example, by means of a pre-applied characteristic curve.

[0049] To evaluate load characteristic parameters, these parameters can also be written, stored, and / or categorized or compared with maximum values. Advantageously, specialized damage calculation algorithms, particularly rainflow counting, can be used, for example, in conjunction with... The Haigh diagram, Haigh diagram, and / or Miner rule can also be used to evaluate load characteristic parameters, thereby enabling, particularly advantageously, a simple determination of the remaining operating duration of the steering component 14. Such damage calculation algorithms are known in themselves and therefore will not be explained in detail below.

[0050] If damage to and / or impending damage to the steering component 14 is identified when evaluating load characteristic parameters, various measures can be taken in response, such as complete shutdown of the steering system 10, degradation of the steering system 10, change of a specific driving mode, alteration of the operation of the steering actuator 16, and / or generation of only indication and / or warning messages.

[0051] Furthermore, load characteristic parameters can be calculated using, in particular, the actual and, for example, pre-calculated load capacity of one of the components, especially the steering component 14, the steering system 10, and / or components operatively connected to the steering system 10. This allows for an advantageous direct statement of the remaining service life of individual components and / or the entire system. The remaining service life can then be read, for example, via the communication interface of the vehicle 12 and / or the steering system 10, or via the onboard computer of the vehicle 12.

[0052] In addition, load characteristic parameters can also be used to determine rack force, thereby further improving the functionality of steering system 10.

[0053] Figure 2 A schematic diagram of a signal flow diagram for monitoring the steering system 10 and, in particular, for evaluating load characteristic parameters is shown.

[0054] The calculation unit 20 is configured to monitor, analyze, and classify load characteristic parameters using the monitoring routine 38. In particular, other influencing parameters, such as the current temperature, can also be fed to the monitoring routine 38 so that they can be considered when evaluating load characteristic parameters. In the present case, the calculation unit 20 is configured to determine the dominant load using the monitoring routine 38, and especially the rainflow counting method. Specifically, the calculation unit 20 is configured to determine whether an external load or an internal and / or system-specific load corresponds to the dominant load.

[0055] If the external load corresponds to the dominant load, the calculation unit 20 is configured to use the first damage calculation routine 40, for example, when using... In the case of the figure, the load characteristic parameters are further processed, and then the degree of external damage to the steering member 14 caused by external forces is determined by means of the first determination routine 42.

[0056] If the internal and / or system-specific load corresponds to the dominant load, the calculation unit 20 is configured to use a second damage calculation routine 44, different from the first damage calculation routine 40, for example, by using another... In the case of the figure, the load characteristics are further processed and then the extent of internal damage to the steering component 14 caused by normal operation of the steering system 10 is determined by means of a second determination procedure 46. In the present case, the damage calculation routines 40, 44 can be used, for example, by means of the... The methods may differ. However, in principle, it is also possible to completely omit the need to determine the internal and / or system-specific loads.

[0057] The calculation unit 20 is then configured to combine the external and internal damage levels into a total damage level of the steering component 14 using a summation routine 48, in order to determine the load and / or condition of the steering component 14. In particular, it can be specified that the external and / or internal damage levels are multiplied by a weighting factor, thereby weighting the external and internal damage levels differently.

[0058] The calculation unit 20 is then configured to assess the overall damage level of the steering component 14 using the evaluation routine 50, for example by comparing it with a limit value, and to initiate a corresponding response, such as generating an indication message, when the limit value is exceeded.

[0059] The design reliably detects and takes into account both internal and / or system-specific load failure mechanisms and external load failure mechanisms (which may differ significantly from those of internal and / or system-specific loads).

Claims

1. A method for monitoring a steering system (10) having a steering handle (24) and at least one steering member (14) to be monitored, wherein load characteristic parameters of at least one steering member (14) of the steering system (10) are obtained and evaluated to determine the state of the steering member (14), and wherein the load characteristic parameters include at least one load of the steering member (14) caused by an external force, characterized in that, In order to determine the load caused by the external force, at least one movement of the steering handle (24) of the steering system (10) is monitored, wherein, when determining the load caused by the external force, the inertia of at least one of the peripheral components of the steering handle (24) and / or the steering handle (24) having dominant inertia is taken into account.

2. The method according to claim 1, characterized in that, At least one motion sensor (32) is used to monitor the movement of the steering handle (24).

3. The method according to claim 2, characterized in that, The motion sensor (32) is different from the steering sensor (34) used to detect the rotating rod signal, and has an extended detection range compared to the steering sensor (34).

4. The method according to claim 2 or 3, characterized in that, The motion sensor (32) is located in the area of ​​the steering handle (24) or in the area of ​​the peripheral component of the steering handle (24) that has dominant inertia.

5. The method according to claim 2 or 3, characterized in that, In order to monitor the movement of the steering handle (24) with the aid of the motion sensor (32), a motion signal that is related to the deflection of the steering handle (24) and / or the speed of the steering handle movement and is different from the acceleration signal is detected, and the acceleration signal is calculated in order to obtain the load caused by the external force from the motion signal.

6. The method according to any one of claims 1 to 3, characterized in that, In order to determine the load caused by external forces, at least one operating parameter of the electrical steering actuator (16) of the steering system (10) is monitored and associated with the movement of the steering handle (24).

7. The method according to any one of claims 1 to 3, characterized in that, The load characteristic parameters include at least one system-specific load generated by the steering component (14) during the operation of the steering system (10) and acting on the steering component (14).

8. The method according to any one of claims 1 to 3, characterized in that, The load characteristic parameter is used to determine the rack force.

9. The method according to claim 1, characterized in that, The method is used during operation in the vehicle (12).

10. A controller (18) having a computing unit (20) for performing the method according to any one of the preceding claims.

11. A vehicle (12) having at least one steering system (10) and a controller (18) according to claim 10, wherein the at least one steering system includes at least one steering member (14).

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