DE102018207176A1 - Method and control unit for detecting rough running of a drive - Google Patents

Abstract

A method (500) for detecting rough running of a drive (102) of a vehicle (100) is described. The method (500) includes determining (501) drive data related to vibrations of the drive (102). In addition, the method (500) includes determining (502) a value of a vibration characteristic (411, 412) based on the drive data, wherein the value of the vibration characteristic (411, 412) indicates an amount of vibration of the driver (102) , Furthermore, the method (500) comprises comparing (503) the determined value of the vibration characteristic (411, 412) with a perception threshold (401, 402) and causing (504) a measure relating to the running noise of the drive (102) depending on the comparison.

Description

The invention relates to a method and a corresponding control unit, which make it possible to detect early uneven running of a drive, in particular an internal combustion engine.

The faulty image "uneven engine running" is a frequent cause of complaints by vehicle users in the workshop environment. Due to the subjective impression of a user often creates an unclear error, which puts the workshop staff in front of great challenges in the complex branched cause determination. This entails a costly and time-consuming troubleshooting, which in turn reduces vehicle availability for the user. Possibly. An unclear error cause can lead to an unnecessary replacement of components. This has the consequence that the error is not corrected and that the user usually has to go to the workshop again, and on the other result from increased warranty costs for the manufacturer or costs for the owner of a vehicle. In addition, the satisfaction of a user decreases. There is thus a need to be able to reliably and efficiently reduce the cause of the error for a vibration felt by a user in the overall system, in particular in a vehicle, to a "troubled engine run".

Furthermore, it may happen that planned service intervals sometimes do not match the individual maintenance requirements of a vehicle. If a vehicle is being serviced too early, it may not be possible or very difficult to detect the occurrence of an imminent defect during maintenance. On the other hand, a late service interval leads to an unplanned workshop visit. Thus, predictive monitoring of the "motor health" of a vehicle is desirable to define on-demand service intervals for vehicle use.

The present document deals with the technical task of efficiently and reliably detecting and monitoring the condition of a drive, in particular an internal combustion engine, in particular in order to determine whether a user feels vibrations in a vehicle, or a restless run of a vehicle Can be attributed to the drive of the vehicle, and / or early countermeasures for a rough running of a drive can initiate.

The object is solved by the independent claims. Advantageous embodiments are described i.a. in the dependent claims. It should be noted that additional features of a claim dependent on an independent claim without the features of the independent claim or only in combination with a subset of the features of the independent claim may form an independent invention independent of the combination of all features of the independent claim, the subject of an independent claim, a divisional application or a subsequent application. This applies equally to technical teachings described in the specification, which may form an independent invention of the features of the independent claims.

According to one aspect, a method for detecting rough running of a drive (in particular an internal combustion engine, such as a gasoline engine) of a vehicle (in particular a road motor vehicle) is described. The method may e.g. be executed by a control unit, in particular by an engine control unit of the vehicle.

The method includes determining drive data related to vibrations of the drive. The drive data are also referred to in this document as motor data or as drive vibration data. The drive data can be recorded directly on the drive, in particular by using one or more sensors already installed in series today. The vehicle may constitute a vibration transmission system comprising the drive as an input to the transmission system and a seat of the vehicle (e.g., the driver's seat) as the output of the transmission system. The vibration transmission system may include one or more engine mounts and the chassis of the vehicle, the engine being supported by the one or more engine mounts on the landing gear. The one or more seats of the vehicle are typically fixedly connected to the chassis of the vehicle.

The drive data may relate to the input of the transmission system and / or the drive data may be acquired at the input of the transmission system. The drive data may thus relate to the excitation of the vibration transmission system of the vehicle.

In particular, the drive data may include sensor data related to the speed of the drive. For example, the drive data may include sensor data relating to the variation of the rotational speed as a function of the crankshaft angle of the crankshaft of the drive. Alternatively or additionally, the drive data may include sensor data relating to vibrations and / or with respect to the acceleration of a housing of the drive (as a function of time). For example, the drive data may include the sensor data of a knock sensor include. This sensor data can be detected by one or more sensors arranged in or on the drive.

The vehicle may include at least one governor configured to at least partially equalize or compensate for differences between moments caused by different cylinders of the engine of the engine. The drive data may include operating data, in particular values of a control error and / or a control variable, of the controller (e.g., as a function of time). For example, a relatively high amount of control error may indicate a relatively high level of running noise of the drive.

Thus, drive data relating to the excitation of the vibration transmission system of the vehicle can be detected. The method further comprises determining a value (at least) of a vibration characteristic based on the drive data. The value of the vibration characteristic may indicate an extent of (periodic and / or stochastic) vibrations of the drive.

As stated above, the drive data may include a time history of a measurand (e.g., speed and / or acceleration) relative to the drive. The time course of the measured quantity can be transformed into the frequency range (for example by means of a discrete Fourier transformation, DFT) in order to determine a spectral power density of the time profile of the measured quantity. It is then possible to determine the proportion of the spectral power density in a frequency range relevant to the human perception of vibrations. In this case, the relevant frequency range can be limited in particular to 25 Hz, 20 Hz or less. The value of the vibration characteristic can then be determined on the basis of the proportion of the spectral power density in the relevant frequency range. An example of such a vibration characteristic is the PSD parameter described in this document. A vibration parameter determined by transformation into the frequency range is particularly suitable for determining the extent of periodic oscillations of the drive.

Alternatively or additionally, the vibration parameter can be determined at least partially in the time domain (in particular in order to determine the extent of stochastic vibrations of the drive). For this purpose, a certain number (e.g., 20, 10, or less) of peaks may be identified in a fixed time interval of the time course of the measurand (e.g., the highest amplitude peaks). Furthermore, the mean value of the amplitude of the determined number of peaks can be determined. The value of the vibration characteristic can then be determined on the basis of the mean value. An example of such a vibration characteristic is the AMP parameter described in this document.

On the basis of the drive data, it is thus possible to determine a value of at least one vibration parameter (which may be composed of several individual parameters). The value of the vibration characteristic then describes in a compact manner the extent of the excitation of the vibration transmission system of the vehicle by (periodic and / or stochastic) vibrations.

The method further comprises comparing the determined value of the vibration characteristic with a sensing threshold. The perception threshold may relate to the output of the transmission system. In particular, the perceptual threshold may relate to the extent to which (periodic and / or stochastic) vibrations of the drive at the input of the transmission system are still perceptible at the output of the transmission system for a human occupant on a seat of the vehicle (and not by the intervening Entrance and exit lying damping system of the vehicle for the perception were eliminated).

The sensing threshold may be based on a psycho-physical measurement of the perception of human occupants of a vehicle with respect to vibrations of the engine. In particular, the perceptual threshold may have been determined within the framework of a statistical study in which a test group of occupants of the vehicle (eg, 20, 50, 80, or more subjects) were tested to determine the extent of (periodic and / or stochastic) vibrations of the vehicle Drive at the entrance of the transmission system was still perceptible to the individual occupants at the output of the transmission system.

The perception threshold may indicate, for example, from which value of the vibration parameter vibrations of the drive are statistically perceived by a certain proportion of human occupants of the vehicle (eg perceived in the abovementioned statistical study). In this case, the perception threshold may be so low that only 25%, 15%, 10% or less of human occupants of the vehicle perceive vibrations of the drive. The perception threshold value can thus be selected to be so low that, based on the determined value of the vibration parameter, a rough running of the drive can be detected even before the rough running (statistically) by a Inmates (eg in 75%, 85%, 90% or more of the cases). The perception threshold value can thus be so low that, when the perception threshold value is reached, no perception of vibrations at the seat of the vehicle by a human occupant takes place (at least statistically, eg for 75%, 85%, 90%, 95%). or more of the human inmates).

In the context of the method, a vibration parameter describing the excitation of the vibration transmission system is thus compared with a perception threshold value describing the output of the transmission system. This allows a particularly early detection of rough running.

The method may further include causing at least one measure related to the rough running of the drive. In this case, depending on the comparison, a measure can be initiated or not. Furthermore, depending on the comparison, a suitable measure can be selected (from a plurality of different possible measures). In particular, a measure can be initiated if it is determined that the value of the vibration parameter reaches or exceeds the detection threshold value. On the other hand, if necessary, no action can be taken.

The measure relating to the rough running of the drive may include causing data relating to the drive to be stored in a memory unit of the vehicle (e.g., in a ring buffer). In this case, the stored (diagnostic) data may preferably be such that the data support a diagnosis for locating the cause of the uneven running of the drive. Thus, during further operation of the drive, it may be caused to store diagnostic data that may be used in later service of the vehicle to identify the cause of the ride with increased reliability and accuracy. Early detection of rough running (even before the rough running is detected by a substantial proportion of occupants of the vehicle) thus enables the detection of large amounts of diagnostic data before the vehicle is serviced by an occupant (e.g., due to perceived rough running).

Alternatively or additionally, the measure relating to the turbulence of the drive may include activating a predictive maintenance (English, predictive maintenance) to cause, during a (otherwise planned or re-scheduled) maintenance date of the vehicle, the cause of the trouble of the drive is corrected. The cause of the fault can thus be remedied even before the uneven running is detected by a significant proportion of occupants of the vehicle. Thus, the comfort and the vehicle availability for a user of a vehicle can be increased.

Alternatively or additionally, the measure relating to the running noise of the drive may include sending a message and / or setting an indicator, wherein the message and / or the indicator indicate that a degree of rough running of the drive has been achieved, such that A noticeability by an occupant is to be expected. For example, an entry may be made to an error memory of the vehicle which may then be considered in a future maintenance of the vehicle (e.g., for predictive maintenance of the vehicle). Alternatively or additionally, an indication to a user of the vehicle may be output (e.g., via a user interface of the vehicle) that maintenance of the drive is required.

Alternatively or additionally, the measure relating to the running noise of the drive may include operating at least one component of the vehicle in response to the drive data to determine an amount of vibration of the drive and / or an extent of the effects of the drive's vibration on a seat of the vehicle Reduce vehicle. The component may e.g. a switchable engine mount, via which the drive is coupled to the chassis of the vehicle, and / or comprise a converter clutch. Thus, one or more measures can be taken to counteract the uneven running and / or the noticeability of the uneven running. Thus, the comfort for a user of the vehicle can be increased.

On the basis of the drive data can be determined if necessary, whether a vibration is caused at a seat of the vehicle by the drive or not.

On the basis of the comparison and / or on the basis of the value of the vibration parameter or the perception threshold value, a predefined operating interval can be predicted, after which it can be expected that the vibrations of the drive will be (statistically) perceptible to an occupant of the vehicle become. For this purpose, historical operating data of drives (for example also with regard to a specific history of a specific drive), in particular of drives of the same type, can be determined and / or provided (for example on a storage unit of the vehicle). The historical operating data can thereby determine the development over time of oscillations of drives (eg the time course of the drive) Value of the vibration characteristic). The operating interval lying ahead up to a limit of appreciability of the turbulence of the drive can then also be predicted on the basis of the historical operating data. By predicting a preceding operating interval, maintenance intervals for a vehicle can be customized (eg, depending on the mode of operation and / or the intensity of operation of the vehicle). Thus, the comfort for a user of the vehicle can be increased.

As part of the method, a sequence of values of the vibration characteristic for a corresponding sequence of different points in time can be determined. For example, a function of the vibration characteristic as a function of the time and / or the mileage of the vehicle can be determined. For this purpose, in each case drive data can be determined on the sequence of different times, from which then the respective values of the vibration parameter for the drive can be determined.

The preceding operating interval may then be extrapolated based on the sequence of values of the vibration characteristic. In particular, the sequence of values of the vibration characteristic can be extrapolated until the perception threshold is reached in order to determine the operating interval lying ahead.

The method may include determining vibration data related to a vibration of a seat of the vehicle. The vibration data may be e.g. by means of an inertial sensor of the chassis of the vehicle and / or by means of an inertial sensor and / or a microphone of a personal electronic device, in particular a smartphone, an occupant of the vehicle (on the seat of the vehicle) are detected.

For the vibration transmission system, a transmission function may be provided with one or more functional parameters. In other words, the vehicle's vibration transmission system may be modeled by a transfer function (e.g., by an analytic function and / or by a learned-in-machine learning function, such as a neural network). In this case, the transfer function may depend on a type (e.g., a type) of the drive and / or a vehicle type of the vehicle. For example, different transmission functions can be provided for different types of drives and / or for different vehicle types.

The value of a function parameter of the transfer function of the vibration transmission system can then be determined and / or adjusted on the basis of the vibration data and on the basis of the drive data. The determined value of the function parameter and / or the adapted transfer function can then be used to detect the rough running of the drive even earlier. In particular, the perception threshold value can be determined and / or adapted on the basis of the value of the function parameter of the transfer function. Alternatively or additionally, the operating interval lying ahead can be predicted up to the noticeability of the uneven running as a function of the value of the function parameter of the transfer function.

The values of the one or more functional parameters of the transfer function of the vibration transmission system can thus be determined directly in the vehicle. Thus, transfer functions for different types or different derivatives of vehicles can be efficiently provided. In particular, a general transfer function for different types or derivatives of vehicles can possibly be provided. The type- or derivative-specific values of the one or more function parameters can then be determined within the respective vehicle.

In the context of the method, the determined value of a function parameter of the transfer function can be compared with a reference value for the function parameter. The condition of a damping element (e.g., an engine mount) of the drive and / or a cause for the turbulence of the drive may then be determined based on the comparison between the detected value and the reference value of the function parameter.

As part of the method, occupant data relating to an occupant of the vehicle may be determined. In this case, the occupant data can display current occupant vital data, feedback from the occupant regarding the sensitivity of the occupant to vibration, and / or a driving style of the occupant. The perception threshold may then be adjusted and / or determined based on the occupant data. Thus, the perceivability of rough running can be tailored to an occupant in an individual way. The feedback of an occupant regarding the sensitivity of the occupant to vibration may e.g. as part of a sensitivity test and the evaluation of feedback from the occupant.

For example, the vehicle may include a user interface (eg as part of a display and control concept). The user interface can be set up via the User interface to capture occupant data. In particular, an occupant can tell the vehicle via the user interface whether the occupant senses a vibration or not. In one example, a test program relating to vibrations may be performed via the user interface. As part of the test program, the drive of the vehicle can be caused to cause (eg sequentially) one or more different test vibrations of the drive. The occupant may then be prompted via the user interface to provide feedback regarding the one or more different test vibrations. In particular, the occupant can be questioned and / or indicate whether and, if so, how much the respective test vibration is perceived as vibration by the occupant. Thus, by means of a test program carried out in the vehicle, the sensitivity of an occupant for vibrations as occupant data can be determined individually. The perception threshold value can then be set as a function of the individually determined occupant data.

Alternatively or additionally, an occupant of the vehicle (in particular the driver) can be observed by one or more occupant sensors while driving a vehicle. Exemplary occupant sensors are an image and / or infrared camera directed at the occupant. On the basis of the sensor data of the one or more occupant sensors, a current status or a current situation of the occupant can then be determined and possibly taken into account as occupant data in the determination and / or adaptation of the perceptual threshold value. Thus, a (quasi) continuous adaptation of the perception threshold value to an occupant of the vehicle can take place, whereby the comfort for an occupant is further increased.

As part of the process, one or more vibrations of the drive can be actively effected. The one or more vibrations can preferably be excited in a frequency range which is outside the relevant frequency range (in particular at 20 Hz, 25 Hz or more), and thus imperceptible to an occupant of the vehicle. Then, vibration data relating to a vibration of a seat of the vehicle may be detected, which is in response to the vibration of the drive caused.

An active oscillation impact for determining a value of a functional parameter of the transfer function can be carried out in a gasoline engine by way of example by changing the mixture quality on individual cylinders (for example, trimming the fuel mass) or by changing the firing angle on individual cylinders.

The value of a function parameter of the transfer function of the vibration transmission system can then be determined on the basis of the vibration data. Alternatively or additionally, based on the vibration data, a cause for the rough running of the drive can be determined. By means of such an active diagnosis, the comfort for a user can be further increased.

In particular, it is possible to define a function space for active diagnoses in dependence on the perception threshold value and / or depending on the (vehicle-specific) transmission function, without an occupant of the vehicle being disturbed by an active diagnosis. An active diagnosis can then help to narrow down the cause of the fault.

According to a further aspect, a control unit for detecting rough running of a drive of a vehicle is described. The control unit is set up to determine drive data relating to vibrations of the drive.

In addition, the control unit is configured to determine a value of a vibration characteristic based on the drive data, wherein the value of the vibration characteristic indicates an amount of (periodic and / or stochastic) vibration of the drive. Furthermore, the control unit is set up to compare the ascertained value of the vibration parameter with a perception threshold value, and to initiate a measure with respect to the rough running of the drive depending on the comparison.

In another aspect, a road vehicle (particularly a passenger car or a truck or a bus or a motorcycle) is described that includes the control unit described in this document.

In another aspect, a software (SW) program is described. The SW program may be set up to be executed on a processor (e.g., on a controller of a vehicle) and thereby perform the method described in this document.

In another aspect, a storage medium is described. The storage medium may include a SW program that is set up to run on a processor and thereby perform the method described in this document.

It should be noted that the methods, devices and systems described herein, both alone and in combination with others described in this document Methods, devices and systems can be used. Furthermore, any aspects of the methods, devices, and systems described herein may be combined in a variety of ways. In particular, the features of the claims can be combined in a variety of ways.

• 1 ein Blockdiagramm eines beispielhaften Antriebsstrangs eines Fahrzeugs;
• 2a einen beispielhaften Zylinder eines Verbrennungsmotors;
• 2b einen beispielhaften Verlauf der Drehzahl eines Verbrennungsmotors als Funktion des Kurbelwellenwinkels;
• 2c ein Blockdiagramm eines beispielhaften Schwingungs-Übertragungssystems in einem Fahrzeug;
• 3a einen beispielhaften zeitlichen Verlauf von Schwingungen an einem Sitz eines Fahrzeugs;
• 3b eine beispielhafte spektrale Leistungsdichte des zeitlichen Verlaufs von Schwingungen aus 3a;
• 3c beispielhafte signifikante Amplituden des zeitlichen Verlaufs von Schwingungen aus 3a;
• 4a beispielhafte Schwingungs-Kenngrößen als Funktion des Ausmaßes der Laufunruhe eines Verbrennungsmotors;
• 4b einen Vergleich zwischen Schwingungs-Kenngrößen für die Vibrationen eines Verbrennungsmotors und Messwerten der Vibration eines Fahrzeugsitzes; und
• 5 ein Ablaufdiagramm eines beispielhaften Verfahrens zur Erkennung von Laufunruhe eines Verbrennungsmotors.

Furthermore, the invention will be described in more detail with reference to exemplary embodiments. Show

• 1 a block diagram of an exemplary powertrain of a vehicle;
• 2a an exemplary cylinder of an internal combustion engine;
• 2 B an exemplary profile of the rotational speed of an internal combustion engine as a function of the crankshaft angle;
• 2c a block diagram of an exemplary vibration transmission system in a vehicle;
• 3a an exemplary time course of vibrations at a seat of a vehicle;
• 3b an exemplary spectral power density of the time course of oscillations 3a ;
• 3c exemplary significant amplitudes of the time course of oscillations 3a ;
• 4a exemplary vibration characteristics as a function of the extent of the rough running of an internal combustion engine;
• 4b a comparison between vibration characteristics for the vibrations of an internal combustion engine and measured values of the vibration of a vehicle seat; and
• 5 a flowchart of an exemplary method for detecting rough running of an internal combustion engine.

As stated above, the present document deals with the reliable, efficient and early detection of the rough running of a drive, in particular an internal combustion engine. In the following, an internal combustion engine will be described as an example of a drive or a drive motor. However, the aspects described in this document are generally applicable to a drive, for example for a hybrid drive and / or for an electric drive.

1 shows exemplary components of a (powertrain of) a vehicle 100 , In particular shows 1 the internal combustion engine (VM) 102 of a vehicle 102 , which has a drive or crankshaft 103 with a gear 106 is coupled to a torque on at least one axle or at least one wheel of the vehicle 100 (not shown) to effect. The VM 102 , the coupling 104 and / or the transmission 106 can through a control unit 101 of the vehicle 100 controlled and / or regulated.

A VM 102 typically includes a plurality of cylinders (eg, 4, 6, or 8 cylinders). 2a shows exemplary a cylinder 201 a VM 102 , Inside a cylinder 201 is a piston 202 movably arranged, whereby by the movement of the piston 202 the crankshaft 203 of the VM 102 is driven (in turn, the drive axle 103 drives (eg via a clutch, a transmission, a dual-mass flywheel, etc.) or the drive axle 103 corresponds). The piston 202 moves through different positions 210 (in particular angle) between a top dead center 211 and a bottom dead center 212 back and forth. The different positions 210 can be considered as (crankshaft) angle 210 , eg between 0 ° and 360 ° (or generally an integer multiple of 360 °), be defined. In this case, the top dead center at 0 ° or 360 ° and the bottom dead center 212 at 180 °.

On the way from top dead center 211 to bottom dead center 212 is via an inlet valve 204 Air and / or a fuel-air mixture 206 in the cylinder 201 sucked (intake stroke). On the other hand, in the cylinder 201 located air and / or in the cylinder 201 located fuel-air mixture 206 compressed when the piston 201 from bottom dead center 212 to top dead center 211 moves (compression stroke). After combustion or heat release can in a Ausschiebetack the burned fuel-air mixture 206 out of the cylinder 201 be encouraged.

Due to the intermittent operation of the internal combustion engine 102 (especially a gasoline engine) creates a kind of "natural" uneven running. The internal cylinder pressures resulting from regular combustion in the individual cylinders 201 a VM 102 lead due to the firing order to a sinusoidal acceleration 220 the crankshaft 102 (see the speed curve 221 as a function of the crankshaft angle 210 in 2 B) , These suggestions are typically dampened by appropriately designed engine mounts and so by the occupants of a vehicle 100 foreclosed.

In case of one on the cylinders 201 unequal distribution of the input necessary for the combustion input variables (in particular of the fuel-air mixture 206 ) is on individual cylinders 201 does too little or too much work. Possible Examples include an insufficient fuel mass or a wrong ignition angle. If a threshold is exceeded here, follows an irregular acceleration of the crankshaft 103 in one of an occupant of a vehicle 100 noticeable and disturbing stimulation results.

Through a targeted investigation and objectification of this noticeable vibration, the uneven running, several goals can be achieved on the way to a predictive maintenance and a pinpointing of the cause of the error. First, the complaint and the sensation of a user in the workshop for the mechanic can be made comprehensible. In this case, a set of measured variables is available, which records the time course and the characteristic boundary and environmental conditions in a statistic. In addition, completed repair measures can be checked for their effectiveness. If there is an improvement in the measured values, the workshop visit can be considered successful. Furthermore, triggers can be selectively set by monitoring the uneven running, triggering on-demand system diagnoses, thus saving both computational and memory resources on one control unit 101 a vehicle 100 can be spared. Finally, it is also possible to detect and predict a system degradation by targeted measurements with appropriate processing. In addition, the knowledge of critical stimuli and their impact on the system response of a vibration transmission system of the vehicle provides 100 the potential for active diagnostics by a vehicle 100 which can not be perceived by a user.

To achieve the above goals, the excitation of vibrations by the internal combustion engine 102 metrologically recorded and identified. Furthermore, the human sensation can be examined starting from a vehicle 100 Inmates are found to be restless. Thus, humans can be characterized as sensors for vibrations.

In order to be able to grasp the sensation of the human being, in the psychophysics proband experiments are carried out, in which the participant is exposed to different stimuli. In doing so, a relatively large sample length (e.g., 80 or more subjects) is preferably acquired because the same stimuli can be evaluated differently by users even under identical constraints. The selected group of subjects may correspond to a so-called lump sample, in which the participants are chosen randomly, but have a valid driving license and thus a certain driving experience. Therefore, a certain expectation of the vibration behavior of a vehicle can not be avoided.

It has been found that the relevant for the evaluation of sensations of a sedentary human pathogen frequencies in a relevant frequency range between 0.3 and 20 Hz.

Also relevant to a person's perception is the response or the sensitivity of the person, which can be defined on the basis of thresholds. Different tests can be carried out which on the one hand define the absolute threshold, ie the smallest detectable threshold, of the subject. On the other hand, thresholds of variation can be identified by the test person giving ratings on suggestions of different intensity and severity.

Furthermore, information about the vibration behavior and the transmission path of a vibration transmission system of a vehicle 100 be determined. For this purpose, sensor data with a relatively high resolution in the time and in the frequency range can be detected. The aim is to determine the transmission path of the vibration transmission system from combustion to the seat rail of a vehicle 100 to be able to capture. To measure the excitation of vibrations by the combustion measuring spark plugs can be used, the internal cylinder pressure, so the origin of the excitation in the interior by the internal combustion engine 102 , record. From this intermittent stimulation and the characteristic spring-damper characteristic of the crankshaft 103 results in a rotational acceleration, which by both a Hall sensor, as well as with an incremental encoder with respect to the crank angle 210 can be recorded. Furthermore, piezoelectric acceleration sensors can be used to detect vibrations on the internal combustion engine 102 capture. On the engine side, acceleration sensors can be mounted on the cylinder head and just in front of the engine mount. Based on the sensor data of these sensors (which are also referred to in this document as engine data or generally as drive data), the excitation of Drehunförmigkeit the crankshaft 103 to the vibrations of the entire engine 102 be correlated. Additionally, to describe the damping characteristics of the engine mount, appropriate sensors may be attached to the engine mount at the transition to the bodywork. In addition, the excitation on the seat rail and the steering wheel of the vehicle 100 be detected to define the vibration characteristics of the chassis and their effects on the occupants.

It can thus be used in 2c illustrated vibration transmission system 230 of a vehicle 100 be defined and quantized. The internal combustion engine 102 causes engine vibrations 241 that have a damping system 231 on the chassis 232 of the vehicle 100 be transferred, and on the chassis 232 chassis vibrations 242 cause, if necessary, for an occupant 260 of the vehicle 100 are noticeable on a seat 233 of the vehicle 100 sitting firmly with the landing gear 232 connected is. The engine vibrations 241 may be based on the sensor data (ie the motor data) of one or more engine sensors 251 be recorded. The suspension vibrations 242 can be based on the sensor data from one or more suspension sensors 252 (eg inertial sensors) are detected. These sensor data are also referred to as vibration data in this document.

In a trial with human volunteers, the threshold of the individual subjects can be defined. For this purpose, a simple staircase method can be used in which the extent of the uneven running is changed in stages (eg by changing the fuel quantity in the fuel-air mixture 206 ). The stimulus and thus the vibrations can be intensified as long as (eg by emaciation of a cylinder 201 ) until the subject feels a vibration. Then the stimulus can be withdrawn again until the stimulus is no longer perceived. This procedure can be repeated until a certain number of rated reversal points is reached. From the reversal points, the sensation threshold for a subject can then be determined.

After the sensation threshold or the absolute threshold or the perception threshold value of a subject has been determined, it is possible in further experiments to define difference thresholds whose intensity varies at random. Different types of vibration characteristics can be investigated. In particular, stochastic oscillations can be investigated, which differ in the frequency of the excitation and in its amplitude. Such stochastic vibrations can e.g. be effected by an adjustment of the ignition angle. Furthermore, periodic vibrations of different magnitudes can be investigated (for example, caused by varying the injection quantity). The aim of the experiments is not only to identify which jumps in the intensity a user can still perceive, but also to detect whether a stochastically occurring stimulus or a periodically recurring stimulus is perceived as more unpleasant. It may be possible for a subject to give an assessment of the smoothness of the engine. In addition, a subject may decide how the subject would react to a rough running in a real situation.

To vibrations of the seat 233 of a vehicle 100 To be able to evaluate one or more vibration characteristics can be defined. 3a shows the means of an acceleration sensor 252 recorded acceleration 311 a vehicle seat 233 as a function of time 310 , The time signal of the acceleration 311 can be transformed into the frequency domain by means of a discrete Fourier transform (DFT). On the basis of the frequency spectrum, a power density spectrum can then be determined. 3b shows the power density 321 (Power Spectral Density) of the acceleration 311 of the vehicle seat 233 as a function of frequency 322 , It is only relevant to the human frequency range 322 (eg between 0.3Hz and 20Hz). The power density 321 can over this relevant frequency range 322 cumulative or integrated to determine a PSD parameter as a vibration characteristic.

The PSD parameter is particularly suitable for comparing periodic oscillations in a defined frequency range. However, stochastic vibrations would be underestimated due to the smaller enclosed area in the integration in the frequency domain compared to periodic excitations.

Therefore, another parameter can be defined whose evaluation takes place in the time domain. For this purpose, in the (possibly low-pass filtered) time signal for the acceleration 311 a certain number of rashes or peaks 331 be extracted with the largest amplitudes (see the rashes 331 in 3c ). To define an AMP parameter 332 can these peaks 331 be averaged.

4a show exemplary courses of the PSD parameter 411 and the AMP parameter 412 as a function of the extent 410 the uneven running of an internal combustion engine 102 , It shows 4a also the standard deviation of the averaged courses. 4a further shows perception thresholds 401 . 402 , which were determined by psychophysical experiments. The first threshold 401 can, for example, indicate the extent 410 of running trouble of 75% or more of the subjects was imperceptible, and the second threshold 402 can, for example, indicate the extent 410 of running troubles of 50% or more of the subjects was imperceptible. Out 4a it can be seen that the rough running of an internal combustion engine 102 based on one or more vibration characteristics (eg the PSD parameter 411 and / or the AMP parameter 412 ) can be detected even before the uneven running by a human is perceived. Thus, one or more vibration characteristics may be used for the predictive maintenance of a vehicle 100 in relation to the rough running of an internal combustion engine 102 be used.

The one or more vibration characteristics can be determined on the basis of measured variables on the engine control unit 101 of a vehicle 100 Are available. In particular, the sensor data of a speed sensor 251 and / or a knock or acceleration sensor 251 be used. Furthermore, controller sizes of one or more control systems for controlling the running of an internal combustion engine 102 used (eg the value of a control error and / or the value of a control variable).

For the characterization of the motor excitation can thus be used in particular the speed. As in 2 B shown, reflects the speed 220 the characteristics of the combustion directly in the speed curve 221 contrary. Through an evaluation or signal analysis of the speed curve 221 can the vibration behavior of the internal combustion engine 102 to be discribed. Examples include the subdivision of a rotation of the crankshaft 103 into different segments (eg one segment for each cylinder 201 ) and the evaluation of the segment cycle times of the different segments. Another possibility is the consideration of the crankshaft acceleration or its gradient. In addition, a Fourier analysis is also expedient, in which both amplitudes and their phases can be assigned to corresponding vibration phenomena. Furthermore, vibrations of the internal combustion engine 102 directly, with accelerometers mounted on the housing. An example is the knock sensor, which also for the detection of low frequencies in the relevant frequency range 322 suitable is. An indirect possibility of finding analysis variables for the excitation is the use of controller outputs. Especially at idle, but also in normal driving cylinder-specific torque differences are typically smoothed by appropriate regulatory intervention. In the process, parameters of the combustion are influenced, which in turn is an indication of the occurrence of rough running on the engine 102 are.

The vibration on the seat rail can be achieved using the inertial sensors of a vehicle 100 be correlated. This is fixed to the vehicle chassis 232 connected and thus shows a similar course as a dedicated sensor on the seat rail.

Thus, both input and output of the multi-mass vibration system can be used 230 through sensors 251 . 252 be pictured in a vehicle 100 is installed. It can be based on the sensor data, a relationship between excitation by the engine 102 and a noticeable appeal in the interior of the vehicle 100 , if applicable also across derivatives. In particular, based on the at the entrance of the vibration system 230 recorded motor data and the output of the vibration system 230 recorded vibration data values of one or more functional parameters of a transfer function can be determined by the vibration system 230 can be described or modeled. The engine data and / or the vibration data can during the operation of a vehicle 100 using sensors 251 . 252 which are fitted as standard in a vehicle 100 are installed. It can also be an adaptation to driving situations, operating situations and / or to the driver of a vehicle 100 respectively.

It can for different derivatives or types of a vehicle 100 a general transfer function can be provided. On the basis of the recorded engine data and vibration data, the vehicle or derivative-specific values for one or more functional parameters can then be determined.

4b shows the course 422 of the AMP parameter based on the sensor data of an inertial sensor 252 of a vehicle 100 was determined and the course 411 AMP parameter determined based on the sensor data of an accelerometer as a function of magnitude 410 the restlessness. In addition, the course becomes 421 an AMP parameter, which was determined on the basis of the sensor data of a speed-correlated control unit size, shown, wherein the speed-correlated control unit size, the excitation of the internal combustion engine 102 represents. Out 4b is the relatively earlier increase in motor-related sensor value (progression 421 ) compared to the seat-related sensor values (progression 411 . 422 ) can be seen. It can be a distance 431 . 432 between the course detected by the engine 421 and the course recorded on the seat 411 . 422 be determined. The distance 431 . 432 can be used to create a state of damping between internal combustion engine 102 and seat 233 and / or to determine a cause for a rough running. Consequently, on the basis of the engine-related sensor data (ie, based on a vibration characteristic, which is determined based on engine data) early uneven running of an internal combustion engine 102 be detected.

5 shows a flowchart of a method 500 for detecting rough running of a drive, in particular an internal combustion engine, 102 of a vehicle 100 , The procedure 500 includes determining 501 of drive data or Engine data with respect to vibrations of the drive, in particular of the internal combustion engine, 102. The drive data or engine data can indicate to what extent by the drive (in particular the internal combustion engine) 102 (periodic and / or stochastic) vibrations at the input of the vibration transmission system 230 of the vehicle 100 (please refer 2c ), which at the entrance the drive (in particular the internal combustion engine) 102 and at the output a vehicle seat 233 having. In this case, the drive data or motor data based on one or more sensors installed as standard 251 of the vehicle 100 be detected (eg a knock sensor, a Hall sensor, an inertial sensor, etc.)

In addition, the process includes 500 the determining 502 a value of a vibration characteristic 411 . 412 (eg the PSD parameter and / or the AMP parameter) based on the drive data or motor data. The value of the vibration characteristic shows 411 . 412 a degree of (periodic and / or stochastic) vibrations of the internal combustion engine 102 at.

Furthermore, the method comprises 500 the comparison 503 the determined value of the vibration characteristic 411 . 412 with a perception threshold 401 . 402 , It can be the perception threshold 401 . 402 , as described in this document, have been determined by means of a psychophysical test procedure. It may then, depending on the comparison, a measure with respect to the rough running of the internal combustion engine 102 be initiated.

In summary, it can be stated that with the help of vibration measurement technology and with the help of subject tests an objectification of the rough running of an internal combustion engine can be made 102 is possible. By correlating the feeling of users 260 with the excitation of vibrations on a vehicle seat 233 can be an absolute threshold 401 . 402 of the stimulus are defined, from which a rough running is felt. Likewise, a relationship or a transfer function between the vibration excitation of an internal combustion engine 102 as an input variable and the vibration are produced on a seat rail as an output variable. Out 4b It can be seen that due to the damping properties of engine mounts and vehicle body with the same Laufunruheaufprägung an earlier increase directly on the engine 102 measured vibration values. On the basis of measured values for describing engine vibrations, a classification of a current excitation by an internal combustion engine 102 be made.

Thus, not only a monitoring of the uneven running is possible, but also a prediction of the increase of the uneven running. For this purpose, for example, the course of the value of the vibration characteristic 411 . 412 be recorded (eg as a function of time or mileage of the vehicle 100 ). It can then be an extrapolation of the course of the value of the vibration characteristic 411 . 412 to determine, for example, at what time and / or at what mileage the perceptual threshold 401 . 402 is reached or exceeded.

The prediction of the increase of the uneven running provides the possibility to set defined triggers for system diagnostics, which allows to record measured data for further online diagnostics or for a later offboard diagnosis in case of occurring errors or degradation of the system. By means of a ring memory architecture even sudden errors can be recorded.

Furthermore, a range of vibration has been defined in which active diagnoses are possible without the comfort of an occupant 260 to influence. For example, vibrations in a frequency range outside the relevant vibration range can be excited 322 so that the vibrations for an occupant 260 are not noticeable. In this case, systems that influence the running restraint can be stimulated in order to use their step response for diagnostic purposes.

The described measures can be applied to different vehicle derivatives with different vibration characteristics. With the availability of input and output variables of the vibration system can by suitable modeling on descriptive parameters of the vibration system 230 or the transfer function of the vibration transmission system 230 getting closed. Thus, the parameters can be adapted both application-wise and with self-adapting algorithms. Targeting for the implementation are parameter estimation methods, but also methods of AI (artificial intelligence) and black-box modeling.

Another advantage of the definition of cross-derivative parameters of the transfer function of the vibration transmission system 230 is that so clearly can be determined whether vibrations from the drive of the vehicle 100 or whether the drive can be excluded as the cause of the vibrations. Furthermore, by comparing the determined parameter values with reference values, the state of the one or more damping components 231 of the vibration transmission system 230 between drive and seat rail (eg a damper diagnosis, an aging diagnosis, etc.) are performed.

It can thus be a Laufunruhetrigger (eg as a function onboard on the engine control unit 101 of the vehicle 100 ) are provided (eg if it is detected that the value of a vibration characteristic 411 . 412 equal to or greater than a perceptual threshold 401 . 402 is). Different internal and / or external vehicle measured variables can be used for the determination of the uneven running characteristic or the vibration characteristic 411 . 412 be taken into account. Furthermore, the driver's sensation in the evaluation of the rough running characteristic number or the vibration characteristic 411 . 412 be taken into account. There may be a continuous adaptation (adaptation) of the one or more intervention thresholds 401 . 402 based on external information about the driver.

Even before approaching a threshold of appreciability 402 The uneven running can be based on the various sensor inputs (eg the engine speed, the engine acceleration, the Intertialsensorik the vehicle 100 , etc.) at least one indication of the error situation with respect to the rough running can be determined. Furthermore, a triggering of detailed diagnoses can be carried out to find the cause of the error. Alternatively or additionally, an initiation of "predictive maintenance" functions can take place, wherein parts of the vehicle 100 to be repaired before a breakdown, possibly even before the inmate 260 An uneven running feels, eg within a regular maintenance interval in the workshop, for example, in an oil service. Alternatively or additionally, an impulse of recorder measurements on the control unit 101 to record the situation of rough running for later offboard evaluations. Alternatively or additionally, one or more compensation measures may be performed to assess the effects of rough running on vibrations of a vehicle seat 233 to reduce.

By the measures described in this document, the rough running of an internal combustion engine 102 be detected early (possibly even before reaching a limit of appreciability for an occupant 260 of the vehicle 100 ). One or more actions may then be taken to assist in diagnosing the fault, to at least partially compensate for the effects of the rough running, and / or to initiate a predictive maintenance action. So can the comfort for a user of the vehicle 100 increase.

The present invention is not limited to the embodiments shown. In particular, it should be noted that the description and figures are intended to illustrate only the principle of the proposed methods, apparatus and systems.

Claims (22)

A method (500) for detecting rough running of a drive (102) of a vehicle (100); the method comprising (500) - determining (501) drive data relating to vibrations of the drive (102); - determining (502) a value of a vibration characteristic (411, 412) based on the drive data, wherein the value of the vibration characteristic (411, 412) indicates an amount of vibration of the driver (102); - comparing (503) the determined value of the vibration characteristic (411, 412) with a perception threshold value (401, 402); and - causing (504) a measure relating to the running noise of the drive (102) depending on the comparison. Method (500) according to Claim 1 in which the perception threshold value (401, 402) indicates from which value of the vibration parameter (411, 412) vibrations of the drive (102) are statistically perceived by a specific proportion of human occupants (260) of the vehicle (100) ; and / or - the sensing threshold (401, 402) is based on a psycho-physical measurement of the perception of human occupants (260) of the vehicle (100) with respect to vibrations of the engine (102); and / or - the sensing threshold (401, 402) is set so low that only 25% or less of human occupants (260) of the vehicle (100) perceive vibrations of the engine (102). Method (500) according to one of the preceding claims, wherein - the vehicle (100) forms a vibration transmission system comprising the drive (102) as input to the transmission system and a seat (233) of the vehicle (100) as output of the transmission system; the drive data relates to the input of the transmission system and / or the drive data is detected at the input of the transmission system; and - The perception threshold (401, 402) refers to the output of the transmission system. The method (500) of any one of the preceding claims, the method comprising (500), - determining occupant data related to an occupant (260) of the vehicle (100); wherein the occupant data in particular current vital data of the occupant (260), feedback from the occupant (260) in Indicating a vehicle occupant sensitivity (260) for vibration, and / or a driving style of the occupant (260); and determining the perception threshold based on the occupant data. Method (500) according to one of the preceding claims, wherein the drive data comprise - Sensor data relating to a rotational speed (220) of the drive (102), in particular with respect to a curve (221) of the rotational speed (220) as a function of a crankshaft angle 210 of a crankshaft (103) of the drive (102); and or - Sensor data relating to vibrations and / or acceleration of a housing of the drive (102). Method (500) according to one of the preceding claims, wherein - The vehicle (100) comprises at least one controller which is adapted to at least partially equalize differences between moments, which are caused by different cylinders (201) of an internal combustion engine of the drive (102); and - The drive data operating data, in particular values of a control error and / or a control variable, the controller include. Method (500) according to one of the preceding claims, wherein - The drive data include a time course of a measured variable (220); and comprising determining (502) the value of the vibration characteristic (411, 412), - Transforming the time course of the measured variable (220) in a frequency range to determine a power spectral density of the time course of the measured variable (220); - determining a portion of the spectral power density in a frequency range relevant to human perception of vibrations (322); wherein the relevant frequency range (322) is particularly limited to 25Hz, 20Hz or less; and - Determining the value of the vibration characteristic (411, 412) based on the proportion of the power spectral density in the relevant frequency range (322). Method (500) according to one of the preceding claims, wherein - The drive data include a time course of a measured variable (220); and comprising determining (502) the value of the vibration characteristic (411, 412), - identifying a certain number of peaks (331) of the time course of the measurand (220); and - determining an average value (332) of an amplitude of the determined number of peaks (331); and - Determining the value of the vibration characteristic (411, 412) based on the average value (332). Method (500) according to one of the preceding claims, wherein - the measure relating to the running noise of the drive (102), causing data relating to the drive (102) to be stored in a memory unit of the vehicle (100); and - The data is such that the data support a diagnosis to find a cause for the running noise of the drive (102). A method (500) according to any one of the preceding claims, wherein the measure relating to the running noise of the drive (102) comprises activating a predictive maintenance action to cause a cause of engine trouble during a maintenance date of the vehicle (100) (102). The method (500) according to one of the preceding claims, wherein the measure comprises in relation to the rough running of the drive (102), Sending a message and / or setting an indicator, wherein the message and / or the indicator indicate that a degree of rough running of the drive (102) has been reached, such that an ability to be felt by an occupant (260) is to be expected; and or - issuing an indication to a user (260) of the vehicle (100) that maintenance of the drive (102) is required. The method (500) of claim 1, wherein the method comprises (500) prediction based on the value of the vibration characteristic (411, 412) and on the basis of the perception threshold value (401, 402) of a preceding operating interval, after expiration of which it is to be expected that the vibrations of the drive (102) will be perceptible to an occupant (260) of the vehicle (100). Method (500) according to Claim 12 , in which - the method (500) comprises determining historical operating data of drives (102), in particular of the same type; the historical operating data indicate a chronological development of vibrations of drives (102), in particular with respect to a temporal course of the value of the vibration characteristic (411, 412); and - predicted operating interval is also predicated on the basis of historical operating data. Method (500) according to one of Claims 12 to 13 wherein - the method (500) comprises determining a sequence of values of the vibration characteristic (411, 412) for a corresponding sequence of different times; and - predicting the preceding operating interval comprises extrapolating the sequence of values of the vibration characteristic (411, 412), in particular until the perception threshold (401, 402) is reached. Method (500) according to one of the preceding claims, wherein the measure relating to the running noise of the drive (102), operating a component of the vehicle (100) in dependence on the drive data, an amount of vibrations of the drive (102) and / or an extent of effects of the vibrations of the drive To reduce drive (102) to a seat (233) of the vehicle (100); and - The component in particular comprises a switchable engine mount, via which the drive (102) to a chassis (232) of the vehicle (100) is coupled, and / or a converter clutch. The method (500) according to any one of the preceding claims, wherein the method comprises (500) - determining vibration data relating to a vibration of a seat (233) of the vehicle (100); - determining a value of a function parameter of a transfer function of vibrations from the drive (102) to the seat (233) based on the vibration data and based on the drive data; and - Determining the perception threshold based on the value of the function parameter of the transfer function. Method (500) according to Claim 16 wherein the transfer function is dependent on: a type of drive (102); and / or a vehicle type of the vehicle (100). Method (500) according to one of Claims 16 to 17 wherein the vibration data are determined by means of: - an inertial sensor (252) of a chassis (232) of the vehicle (100); and / or an inertial sensor and / or a microphone of a personal electronic device, in particular a smartphone, an occupant (260) of the vehicle (100). Method (500) according to one of Claims 16 to 18 wherein the method comprises (500), - comparing the determined value of the function parameter with a reference value for the function parameter; and determining a state of a damping element of the drive (102) and / or a cause for the running noise of the drive (102), based on the comparison between the determined values and the reference value of the function parameter. The method (500) according to any one of the preceding claims, wherein the method comprises (500) - causing a vibration of the drive (102); - detecting vibration data relating to a vibration of a seat (233) of the vehicle (100) in response to the vibration of the drive (102) caused; and - determining a value of a function parameter of a transfer function of vibrations from the drive (102) to the seat (233) based on the vibration data; and or - Determining a cause for the rough running of the drive (102) based on the vibration data. A method (500) according to any one of the preceding claims, wherein the method (500) comprises determining, based on the drive data, whether or not vibration is caused at a seat (233) of the vehicle (100) by the drive (102). Control unit (101) for detecting rough running of a drive (102) of a vehicle (100); wherein the control unit (101) is set up, To determine drive data relating to vibrations of the drive (102); determine a value of a vibration characteristic (411, 412) based on the drive data, the value of the vibration characteristic (411, 412) indicating an amount of vibration of the driver (102); - Compare the determined value of the vibration characteristic (411, 412) with a perception threshold (401, 402); and - to initiate a measure relating to the rough running of the drive (102) depending on the comparison.

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