Method and device for wear analysis of components of motor vehicle

Abstract

The invention relates to a method for wear analysis of at least one component of a motor vehicle. In this case, sensor data is acquired by means of at least one sensor, said sensor data being acquired in order to provide at least one basic function of the motor vehicle and / or of a drive train of the motor vehicle. Data dependent on a current state of the at least one component is calculated using a model, wherein the model obtains the acquired sensor data as an input variable. Information about the current wear of the at least one component is ascertained using the calculated data.

Description

Technical Field

[0001] The invention relates to a method and a corresponding device for wear analysis of components of a motor vehicle. Background Art

[0002] The components of the drive train are designed according to the stored load profile. A “load profile” can be understood as a statistical load-dependent distribution of one or more physical variables, such as a time dependency of a temperature rise or a dependency of a torque with respect to a rotational speed.

[0003] The load profile is usually based on assumptions or is transmitted from field data of the internal combustion engine vehicle and has to be adjusted accordingly. However, field data of the drive train are often insufficient to verify or adjust the load profile with field data. Furthermore, the state of the components or the state of the entire drive train cannot be checked in the field, but only the statistical probability of failure can be taken into account.

[0004] One possibility for aligning the stored load profiles with field data and, if necessary, adjusting the load profiles during operation is wear analysis. This allows vehicle manufacturers, spare parts manufacturers or even end users (such as fleet operators or private users) to be informed at regular intervals of the current state of wear or aging (English: "State of Health") of the respective drive train.

[0005] A method for optimizing a vehicle is known from EP 1 623 284 B1, in which the vehicle is simulated. AT 518850 B1 relates to another method for simulation-based analysis or optimization of a motor vehicle. DE 10 2019 202 980 A1 relates to a system for determining analysis data for improving a mobile system. DE 10 2019 219436 A1 relates to a method for identifying load-induced states. Summary of the invention

[0006] The invention provides a method and a device for wear analysis of at least one component of a motor vehicle having the features of the independent claims.

[0007] Preferred embodiments are the subject matter of the respective dependent claims.

[0008] According to a first aspect, the invention therefore relates to a method for wear analysis of at least one component of a motor vehicle. In this case, sensor data are acquired by at least one sensor, wherein the sensor data are acquired for providing at least one basic function of the motor vehicle and / or the drive train. Using a model, data dependent on the current state of the at least one component are calculated, wherein the model receives the acquired sensor data as input variables. Using the calculated data, information about the current wear of the at least one component is ascertained.

[0009] According to a second aspect, the invention relates to a device for wear analysis of at least one component of a motor vehicle. The device comprises an interface, which is designed to receive sensor data from at least one sensor of the motor vehicle, wherein the at least one sensor acquires sensor data for providing at least one basic function of the motor vehicle and / or the drive train. The device further comprises a calculation device, which is designed to calculate data dependent on the current state of the at least one component using a model, wherein the model receives the acquired sensor data as input variables and determines information about the current wear of the at least one component using the calculated data.

[0010] According to the invention, sensor data acquired by sensors are used to calculate data dependent on the current state of at least one component, which sensor data are already required to provide basic functions of the motor vehicle and / or the drive train. Such sensors are thus sensors that are already present in the motor vehicle as standard. In particular, these sensors are not additional dedicated sensors that are provided specifically for wear analysis.

[0011] The invention thus makes it possible to provide a very precise wear analysis, i.e. the determination of information about the current wear, in a fast and cost-effective manner using software models or algorithms without the need for additional sensors, thereby making it possible to dispense with additional sensors or to save sensors that have been available to date.

[0012] Compared to wear analysis based purely on load profiles, the currently existing damage of the corresponding components can be not only calculated but also actually recorded by taking into account the sensor data. It is thus possible to measure not only the theoretical state of the corresponding components of the motor vehicle but also their actual state. This actual state of the components of the motor vehicle can then be adjusted with the stored damage (permissible within the scope of the service life), for example resulting from the corresponding load profile. In addition, it can be recorded that the components show unusual properties, such as high vibrations, pressures, unusual current patterns, etc. This makes it possible to predict the remaining wear with great accuracy.

[0013] Furthermore, it is possible to replace a component at a repair station before it is destroyed or seriously damaged. This avoids unnecessary and larger repairs.

[0014] By having a precise knowledge of the remaining wear and tear, it is possible to indicate the respectively remaining, precisely defined, minimum remaining service life when the motor vehicle is resold. As a result, the residual value or resale value of the motor vehicle can be determined much more accurately.

[0015] Furthermore, the components can be designed much more accurately for the actual loads or damage during the service life by means of a learning process that can be optionally implemented in the wear analysis function. This can reduce the total weight of the motor vehicle, reduce material costs, and reduce costs for component testing as well as for testing the entire drive train. Furthermore, the service life guarantee or warranty can be increased if necessary.

[0016] Furthermore, sensors in the electric drive train can also be omitted since the loads on the corresponding components are known, which in turn allows for savings in costs and weight.

[0017] A “sensor that acquires sensor data in order to provide at least one basic function of the motor vehicle and / or the drive train” can be a sensor that is present as standard, for example for detecting rotational speed and torque, etc. A “basic function” can be, for example, providing a desired drive torque, that is, for example, accelerating or braking the vehicle according to the driver's request. Basic functions can also include monitoring of the coolant circuit, etc. Thus, the basic function is necessary for standard operation of the motor vehicle and / or the drive train.

[0018] According to another embodiment of the method for wear analysis of at least one component of a motor vehicle, only the acquired sensor data are taken into account for the calculation of the data. In particular, the model does not receive any sensor data from other dedicated sensors, which may be provided specifically for the wear analysis, for example. This makes it possible to save such additional sensors. The method is "sensorless" because no dedicated sensors can be provided, but only sensor data of sensors that are already installed in the motor vehicle as standard are evaluated in order to carry out the wear analysis.

[0019] According to another embodiment of the method for wear analysis of at least one component of a motor vehicle, the collected sensor data include at least one of the parameters of the torque of the motor of the motor vehicle, the speed of the motor, the direct current loaded on the electric drive system (especially loaded on the power electronics of the electric drive system), the direct voltage loaded on the electric drive system, the alternating voltage loaded on the motor, the temperature of the power electronics and / or the motor, the coolant volume flow rate and the coolant temperature. The sensor data can also appear multiple times respectively, so that multiple temperatures can be measured, for example. Thus, the sensor data can be collected in particular by a sensor installed in the drive system. In particular, the measured torque, speed or current can be taken into account. In one embodiment, other sensor data are not used for wear analysis.

[0020] According to another embodiment of the method for wear analysis of at least one component of a motor vehicle, the calculated data include at least one temperature of at least one component. The data can also include at least one variable of the hot spot temperature of the stator, the temperature in the film capacitor, the temperature of the power module, the temperature in the transmission, the temperature of the transmission oil, the temperature of the cooling medium at different locations within the drive train, the direct current, the alternating current, the torque or rotational speed at the output of the E-axis, the torque and rotational speed at the transition from the electric machine to the transmission or between the individual transmission stages, the temperature of the coupling system or the decoupling system, the temperature of the parking lock system or other components of the drive train. The data can also occur multiple times, for example, can include the hot spot temperatures of multiple stators.

[0021] According to another specific embodiment of the method for wear analysis of at least one component of a motor vehicle, the model for calculation data models the at least one component. This may be a finite element model, for example.

[0022] According to another specific embodiment of the method for wear analysis of at least one component of a motor vehicle, remaining wear of the at least one component is predicted by comparing determined information about current wear of the at least one component with predefined information about maximum permissible wear of the at least one component.

[0023] According to another specific embodiment of the method for wear analysis of at least one component of a motor vehicle, the information about the current wear of the at least one component comprises a ratio of a variable describing the current wear to a variable describing a maximum permissible wear.

[0024] According to another embodiment of the method for wear analysis of at least one component of a motor vehicle, the predetermined information about the maximum permissible wear of the at least one component includes a load profile of the at least one component. As a result, the stored load profile can be adjusted, that is, verified, with field data and, if necessary, adjusted during operation. With the help of the load profile, it can be determined what the maximum permissible wear of the component is within the service life. With the help of a damage model (damage formula with corresponding coefficients), the current damage can be calculated, with which the maximum permissible damage within the service life is adjusted and the remaining damage or the predicted remaining service life is determined.

[0025] According to another embodiment of the method for wear analysis of at least one component of a motor vehicle, the remaining operating time of the at least one component and / or the remaining cruising range of the motor vehicle is determined using the predicted remaining wear of the at least one component. The remaining operating time and / or the remaining cruising range can be determined by carrying out an extrapolation of the wear of the component assuming that the driver continues to drive in the previously determined driving style. As an alternative, a driving profile can be stored in order to be able to characterize a standard driver.

[0026] According to another embodiment of the method for wear analysis of at least one component of a motor vehicle, the wear state (English: State of Health) is determined using the predicted remaining wear of the component. The wear state can, for example, indicate the current wear as a percentage of the wear (maximum damage) permitted over the entire service life.

[0027] According to another specific embodiment of the method for wear analysis of at least one component of a motor vehicle, unusual wear characteristics of the component are recorded if the sensor data and / or the information about the current wear of the component have unusual characteristics. This can mean, for example, that the evaluation of the sensor data and / or the information about the current wear of the component is outside a predefined range, that is to say, for example, falls below or exceeds a predefined threshold value.

[0028] According to another embodiment of the method for wear analysis of at least one component of a motor vehicle, a warning signal and / or a treatment suggestion is output to a user based on the predicted remaining wear of the at least one component. The user can be, for example, the driver of the vehicle, the manufacturer, the fleet operator, etc. If unusual wear characteristics of the component are detected, a warning signal can be output, for example. The warning signal can indicate, for example, that a maximum permissible wear is about to be reached or that an incompatibility of the component is recorded based on sensor data.

[0029] According to another embodiment of the method for wear analysis of at least one component of a motor vehicle, the remaining wear of the component or the wear state of the component is communicated to a vehicle manufacturer, a spare parts manufacturer (in particular the manufacturer of the component) and / or an end user (fleet operator or private user) at regular intervals or continuously.

[0030] According to a further specific embodiment of the method for wear analysis of at least one component of a motor vehicle, the component is an electric drive or a part of an electric drive.

[0031] According to a further specific embodiment of the method for wear analysis of at least one component of a motor vehicle, a prediction of the remaining wear of the component is carried out with the aid of an evaluation device of the motor vehicle.

[0032] According to a further specific embodiment of the method for wear analysis of at least one component of a motor vehicle, a prediction of the remaining wear of the component is carried out with the aid of an evaluation device located outside the motor vehicle.

[0033] According to another embodiment of the method for wear analysis of at least one component of a motor vehicle, the component can be a shaft sealing ring, a bearing, a bearing grease, a transmission oil, a gear, a differential, a side toothing, a spur gear, a pinion, a plug connection, a parking lock system, a transmission, a transmission housing, a shaft, a seal, an output shaft, an input shaft, a coupling system or a decoupling system (disconnect unit), a locking ring, a welded component or a screw. In addition, it can be an electric motor or its components (such as a rotor, a stator, an insulation part or a bearing, a bearing grease or a locking ring). In addition, it can be an inverter or its components (such as a power module including a B6 bridge or a B12 bridge or a Bx bridge, a discharge circuit, a DC voltage capacitor, an EMC filter, a film capacitor, etc.). In addition, it can be a system or its components (such as a system housing, a buffer element or a seal, such as a liquid seal or an intermediate layer seal, a radial shaft sealing ring, a component for voltage grounding, a screw, a cable or a liquid, such as oil, water or a water-glycol mixture). BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A schematic block diagram of a device for wear analysis of a component of a motor vehicle is shown; and

[0035] Figure 2 A flow chart of a method for wear analysis of a component of a motor vehicle is shown.

[0036] The numbering of the method steps is for the sake of clarity and should generally not imply a specific temporal sequence. In particular, a plurality of method steps can also be carried out simultaneously. DETAILED DESCRIPTION

[0037] Figure 1 A schematic block diagram of a device 1 for wear analysis of components of a motor vehicle is shown. The motor vehicle can be an electric vehicle or a hybrid vehicle in particular. The device 1 can be arranged in the motor vehicle or can also be used outside the motor vehicle (for example as an external analysis system).

[0038] The device 1 comprises an interface 11, which is coupled to at least one sensor 2, for example, via a CAN bus. The at least one sensor 2 is a standard sensor, which is already present in the motor vehicle and does not have to be provided specifically for wear analysis. The sensor data acquired by the at least one sensor 2 include, for example, the torque of an electric motor of the motor vehicle, the speed of the electric motor, the direct current applied to the electric motor, the direct voltage applied to the electric motor, the alternating voltage applied to the electric motor, the temperature of the electric drive train of the electric motor, the coolant volume flow or the coolant temperature.

[0039] The device 1 also includes a storage device 12 with at least one non-volatile data memory for storing sensor data received from at least one sensor 2. Previously provided information about the maximum permissible wear of the component is also stored in the storage device 12. This can be at least one load profile of the component.

[0040] Furthermore, the device 1 comprises a computing device 13, such as a microprocessor, an integrated circuit, etc. The computing device 13 uses the acquired sensor data to calculate data which depend on the current state of at least one component or are linked to this state (that is, in particular may depend on the current wear state of at least one component).

[0041] Using the calculated data, the calculation device 13 determines information about the current wear of the at least one component.

[0042] The computing device 13 can be situated in the motor vehicle and / or in the device 1 or outside the motor vehicle and / or outside the device 1 .

[0043] Furthermore, the calculation device 13 can determine the remaining wear of the component by using the ascertained information about the current wear of the component for comparison with predefined information about the maximum permissible wear of the component.

[0044] A wear analysis can be carried out, for example, for the components listed in Table 1 with corresponding exemplary damage mechanisms (in particular for an analysis based on a load profile).

[0045]

[0046]

[0047] Table 1

[0048] Figure 2 A flow chart of a method for wear analysis of a component of a motor vehicle, such as a component of an electric drive, is shown. The method can be implemented using the device 1 described above. Conversely, the device 1 described above can be designed to implement all or individual steps of the method steps described below. In particular, all calculation steps can be implemented by the calculation device 13.

[0049] In a first method step S1 , a vehicle simulation is carried out, taking into account vehicle data, data about the drive train and / or a driver profile ascertained from past measurement data. In particular, frequency distributions of torque, rotational speed and / or voltage can be ascertained.

[0050] In the second method step S2, the variables determined in the first method step S1 (e.g., temperature in relation to frequency) can be used as input variables for the simulation model in order to simulate the parameters required for calculating the maximum permissible wear of the component. The simulation model can include, for example, a thermal simulation of the component in order to determine, for example, the maximum temperature of the component (hot spot temperature).

[0051] In a third method step S3 , a wear calculation is carried out in order to determine the maximum permissible wear of the component. The maximum permissible wear of the component can be stored in the memory device 12 .

[0052] In a fourth method step S4 , measurements are carried out during operation of the motor vehicle by means of at least one sensor 2 provided as standard in order to detect sensor data. The sensor 2 detects, for example, the torque, the rotational speed and / or the current of the drive train.

[0053] In a fifth method step S5, data dependent on the current state of at least one component are calculated using a model, wherein the input parameters or input variables of the model include the acquired sensor data. For example, the hottest temperature occurring at the stator can be determined with the aid of the thermal model.

[0054] The model can include, for example, a temperature model or a plurality of temperature models for at least one rotor, at least one stator, at least one transmission, at least one oil, at least one AC voltage busbar, at least one DC voltage busbar, at least one power module, at least one intermediate circuit capacitor, at least one electromagnetic compatibility (EMC) filter, and at least one coolant fault diagnosis. The corresponding components are thus described and simulated completely or partially by the model and corresponding values ​​for the temperature are calculated as a function of the input parameters.

[0055] The model can also include, for example, a torque accuracy model, a speed accuracy model, a voltage ripple model, a transmission protection function, an AC voltage-current- and voltage-determining model consisting of a given DC current and a given DC voltage, or a motor current characteristic analysis for bearings, rotors, stators, transmission teeth or oil.

[0056] The sensor data can be adjusted with a target value in order to record any inconsistencies. The inconsistencies can also be incorporated into the calculation of the current wear of the at least one component.

[0057] Furthermore, it can be provided that in a fifth method step S5 the sensor variable is calibrated with a target value in order to register any inconsistencies.

[0058] In a sixth method step S6 , information about the current wear of at least one component is ascertained. For example, for a predetermined temperature of a component, the number of occurrences and / or the duration of the stay of this temperature can be determined in each case.

[0059] In the seventh method step S7, the information about the current wear of the component is compared with the information about the maximum permissible wear of the component that has been determined. For example, the histograms of the temperature rise can be compared with each other in order to determine to what extent the maximum permissible wear has been reached. The remaining wear is then predicted and output. This can be, for example, a percentage that indicates how great the remaining residual wear is. As an alternative to the temperature distribution (maximum temperature rise with respect to frequency), for example, a damage distribution (damage with respect to time) or total damage can also be calculated from the temperature rise and / or temperature change. As an alternative, this damage distribution or total damage is then adjusted with the maximum permissible damage distribution or total damage within the service life.

[0060] In an eighth method step S8 , it can be determined whether the predicted remaining wear exceeds a predetermined threshold value. If this is the case, a warning signal and / or a handling suggestion can be output in method step S9 .

[0061] The prediction of the remaining wear of the components can be carried out in the evaluation device of the motor vehicle or in an external evaluation device located outside the motor vehicle. Thus, for example, only the local data in the drive train can be acquired and collected. The local data are then transmitted via the diagnostic interface in the service station and can thus be processed with a large computing power (outside the drive train).

[0062] Furthermore, it can be provided that conclusions are drawn from these results, i.e., for example, the remaining service life or the remaining mileage is ascertained or also warnings and / or handling suggestions due to incompatibilities are forwarded to the end customer, the system manufacturer, the fleet operator and / or the drive train manufacturer or also to a subsidiary manufacturer.

[0063] Furthermore, it can be provided that only the field data in the drive train is acquired and collected and transmitted to the customer, for example via a CAN interface, for example to a cloud provided by the customer or a spare parts manufacturer or a drive device manufacturer. The field data can thus be processed with a large computing power (outside the drive train).

[0064] Furthermore, it can be provided that sensor data in the drive train are recorded and processed, that is, the current wear is calculated from the sensor data and is adjusted with the stored maximum permissible wear. In the service station, the information about the current wear or all data is transmitted via the diagnostic interface and can thus be further processed with a large computing power (outside the drive train) or used for learning processes and statistics. In this way, the stored load profiles of the components and the resulting maximum permissible wear can be adjusted at regular intervals.

[0065] Furthermore, it can be provided that sensor data in the drive train are acquired and processed, that is, the current wear is calculated from the sensor data and is adjusted with the stored maximum permissible wear. These or all data are transmitted to a user or a cloud via an interface, such as a CAN connection, and can thus be further processed with a large computing capacity (outside the drive train) or used for learning processes and statistics. The stored load profiles can also be adjusted.

Claims

1. A method for wear analysis of at least one component of a motor vehicle, comprising the following steps: Sensor data are collected (S4) by at least one sensor (2), wherein: collecting the sensor data for providing at least one basic function of the motor vehicle and / or a drive train of the motor vehicle; calculating (S5) data dependent on the current state of the at least one component using a model, wherein the model receives the acquired sensor data as input variables; and Using the calculated data, information about the current wear of the at least one component is ascertained ( S6 ).

2. The method according to claim 1, wherein: The collected sensor data include at least one of the torque of the motor of the motor of the motor vehicle, the speed of the motor of the motor, the DC current loaded on the electric drive system of the motor vehicle, the DC voltage loaded on the electric drive system, the AC voltage loaded on the motor, the temperature of the electric drive system of the motor, the coolant volume flow rate and the coolant temperature.

3. The method of claim 1 or 2, wherein the calculated data comprises at least one temperature of the at least one electrical component.

4. A method according to any one of the preceding claims, wherein: A model for computing the data models the at least one component.

5. The method according to any one of the preceding claims, further comprising the following steps: The remaining wear of the at least one component is predicted using the ascertained information about the current wear of the at least one component in comparison with predefined information about the maximum permissible wear of the at least one component.

6. The method according to claim 5, wherein: The predetermined information about the maximum permissible wear of the at least one component comprises a load profile of the at least one component.

7. The method according to claim 5 or 6, wherein: The predicted remaining wear of the at least one component is used to determine a remaining operating time of the at least one component and / or a remaining cruising range of the motor vehicle.

8. The method according to any one of claims 5 to 7, wherein: A warning signal and / or a handling suggestion is output to a user based on the predicted remaining wear of the at least one component.

9. The method according to any one of claims 5 to 8, wherein: A prediction of the remaining wear of the at least one component is carried out with the aid of the evaluation device (1) of the motor vehicle.

10. Device (1) for carrying out a wear analysis on at least one component of a motor vehicle, comprising: An interface (11) is designed to receive sensor data from at least one sensor (2) of the motor vehicle, wherein The at least one sensor (2) collects sensor data for providing at least one basic function of the motor vehicle and / or a drive train of the motor vehicle; as well as A calculation device (13) is constructed for calculating data dependent on a current state of the at least one component using a model, wherein the model receives acquired sensor data as input variables, and wherein the calculation device (13) is also constructed for determining information about current wear of the at least one component using the calculated data.

Images