WO2021115837A1

WO2021115837A1 - Method and vehicle for transferring diagnostic data of the vehicle to an evaluation station, and evaluation system

Info

Publication number: WO2021115837A1
Application number: PCT/EP2020/084048
Authority: WO
Inventors: Stefan Herrmann; Bernhard Schlegel; Philipp Reinisch
Original assignee: Bayerische Motoren Werke Aktiengesellschaft
Priority date: 2019-12-10
Filing date: 2020-12-01
Publication date: 2021-06-17
Also published as: DE102019133837A1

Abstract

The invention describes a method for transferring diagnostic data of a vehicle (10), more particularly a passenger car or heavy goods vehicle, to an evaluation station (20), the method comprising the following steps: a) detecting initial data (D0) comprising a plurality of signal time functions generated in particular by one or more sensor units (110) and/or one or more communication units (120) of the vehicle (10); b) prefiltering the initial data (D0), wherein prefiltered diagnostic data (DV) is generated by filtering signal values with redundant information out of the plurality of signal time functions of the initial data (D0); and c) transferring the prefiltered diagnostic data (DV) to the evaluation station (20). Furthermore, the invention describes a computer-readable medium according to claim 14, a vehicle according to claim 10 and an evaluation system according to claim 13. The invention allows reduction of the volume of the data (diagnostic data) to be transferred to the evaluation station without the loss of information needed for the analysis of the vehicle status.

Description

Method and vehicle for transmitting diagnostic data of the vehicle to an evaluation station and evaluation system

DESCRIPTION

The invention relates to a method for transmitting diagnostic data of a vehicle to an evaluation station according to claim 1, a vehicle which is designed to transmit diagnostic data to an evaluation station according to claim 10, an evaluation system according to claim 13 and a computer-readable medium according to claim 14.

In the development of vehicles, in particular passenger cars and trucks, (test) vehicles or development vehicles are typically tested in road traffic and / or on separate test tracks, depending on the stage of development.

During a test drive of such a vehicle, information about the vehicle is conventionally continuously acquired and recorded. The recorded information is data that includes the signals from the vehicle buses, which is also referred to as trace data. Trace data can include sensor data as well as actuator data and, in general, communication data of the vehicle buses.

Typically, after a test drive has been completed, the recorded data is transmitted to an evaluation station. Using the transmitted data, the condition of the vehicle can be determined and analyzed in the evaluation station. Furthermore, errors in the electrics and software of the current state of development can be found and eliminated using the transmitted data.

Trace data typically have signal values that are provided and recorded at fixed time intervals such as 50 ms, in particular 20 ms, preferably 10 ms, by the control units, the sensors and / or actuators and sent to the evaluation station either after the test drive has been completed or during the test drive be transmitted. With an increasing number of development vehicles and an increasing number of sensors and / or actuators installed in the development vehicles, the amount of data that is recorded during a test drive and transmitted to the evaluation station increases. In addition, there is a tendency for faster vehicle bus systems to be installed, which means that the fixed time intervals for the trace data are getting smaller and smaller, which means that the amount of data continues to increase.

The increase in the amount of data to be transmitted means that sometimes high latency times can arise when the data is transmitted to the evaluation station, since the data is generated faster than it can be transmitted. In addition, the technical effort required to store the data before transmission (in the vehicle) as well as after transmission (in the evaluation station) increases.

The prior art to date shows that there is still no satisfactory technical solution for the disadvantages described above.

It is therefore the object of the present invention to provide a method and a vehicle in which it is possible to reduce the amount of data to be transmitted (trace data) without losing information that is necessary for the analysis of the vehicle condition.

The object is achieved by a method for transmitting diagnostic data of a vehicle to an evaluation station according to claim 1, a vehicle which is designed to transmit diagnostic data to an evaluation station according to claim 10, an evaluation system according to claim 13 and a computer-readable medium according to claim 14.

In particular, the object is achieved by a method for transmitting diagnostic data of a vehicle, in particular a passenger car or truck, to an evaluation station, the method comprising the following steps: or several sensor units and / or one or more communication units of the vehicle are generated; b) prefiltering the initial data, with prefiltered diagnostic data being generated by filtering out signal values with redundant information from the plurality of signal profiles of the initial data; and c) transferring the pre-filtered diagnostic data to the evaluation station.

An essential core idea of the invention is based on the knowledge that redundant information is present in the initial data (in the recorded trace data), these redundancies being filtered out or reduced in a prefilter step before the prefiltered diagnostic data is transmitted to the evaluation station.

The unfiltered initial data typically have a large amount of redundant information if a vehicle state does not change over a longer period of time (for example during stationary phases at traffic lights, standstill, or driving at constant speed). The redundancies in the initial data and thus the amount of data in the initial data can be reduced by removing signal values from individual signal profiles of the initial data that follow one another and remain at least essentially unchanged.

Signal values that have no additional information content are considered redundancies or redundant information, which is the case in particular when the signal values of a signal curve change essentially only slightly (or not) (remain constant). If the redundant information is filtered out, the amount of data in the pre-filtered diagnostic data is significantly less than the amount of data in the unfiltered initial data.

In addition, redundant information is not relevant for further evaluations in the evaluation station, so that filtering out redundant information from the initial data before the transmission of the pre-filtered diagnostic data also accelerates the evaluation in the evaluation station. Furthermore, the technical effort and the resulting costs for storing the data in the evaluation station can be reduced.

A signal curve can be understood as a sequence of recorded signal values of a state variable (for example the speed of the vehicle, the acceleration of the vehicle, a steering angle, etc.), where a signal value is to be understood as a signal amplitude at a (discrete) point in time. Filtering out can be understood to mean removing certain signal values.

An evaluation station is arranged in particular outside the vehicle and can also be referred to as a central point. For example, a single evaluation station can also be responsible for several (development) vehicles, with the vehicles sometimes being located far away from the evaluation station.

In one embodiment, when pre-filtering the initial data, signal values are filtered out if two or more successive signal values of the signal curves remain at least essentially unchanged.

As a result, signal values which have no information content can be removed in a simple manner from the signal curves of the initial data. This can reduce the amount of data.

In particular, when pre-filtering the initial data, signal values are filtered out if a signal value change to the directly preceding signal value and / or to a predetermined number of previous signal values is less than a predetermined change threshold value, whereby redundant information can also be easily removed from the initial data. In addition, the sensitivity of the prefilter can be fine-tuned by setting the predetermined change threshold value. In particular, it is possible to define different change threshold values for the different signal curves of the initial data.

The pre-filtered diagnostic data are preferably transmitted to the evaluation station via a wide area connection, WAN, which enables the pre-filtered diagnostic data to be transmitted from the vehicle to the evaluation station over particularly long distances. Long-distance connections can extend over particularly long distances (for example countries and continents).

In a preferred embodiment, the signal profiles of the initial data are approximated in sections by means of adaptation functions before and / or after the prefiltering. In particular, linear fit functions or Polynomials of a higher degree, such as, for example, polynomials of the second degree, third degree or higher, are used for segment-wise approximation of the adaptation functions to the signal profiles of the initial data. This can further reduce the amount of data in the initial data.

It is preferred that before and / or after the pre-filtering, the signal curves of the initial data are smoothed and / or signal noise is reduced, preferably by low-pass filtering the signal curves. By reducing the signal noise applied to the signal curves, information that is not required for the analysis of the vehicle condition can be filtered out before transmission, so that the amount of data to be transmitted is reduced.

In particular, the signal curves of the initial data and / or the pre-filtered diagnostic data are temporarily stored before they are transmitted to the evaluation station in the vehicle, which makes it possible, for example, if there is a poor connection quality between the vehicle and the evaluation station, to combine the initial data and / or the pre-filtered diagnostic data to be retransmitted later.

It is preferred that steps a) to c) are repeated, preferably cyclically, at fixed time intervals. In particular, the fixed time intervals can be, for example, 10 ms, 50 ms, 100 ms or more.

The predetermined number of preceding signal values is preferably 2 or greater, in particular greater than 5, preferably greater than 10, as a result of which the sensitivity of the pre-filtering can be adjusted.

Furthermore, the object of the invention is achieved by a vehicle, in particular a passenger car or truck, which is designed to transmit diagnostic data to an evaluation station, preferably according to the method of the above type, the vehicle having the following:

Acquisition unit, which is designed to acquire initial data that include a plurality of signal curves that are generated in particular by one or more sensor units and / or one or more communication units of the vehicle; Pre-filter unit which is designed to pre-filter the initial data, pre-filtered diagnostic data being generated by filtering out signal values with redundant information from the plurality of signal profiles of the initial data; and

Transmission unit which is designed to transmit pre-filtered diagnostic data to an evaluation station, in particular via a wide area connection.

The vehicle according to the invention has the advantages that have already been described in relation to the method for transmitting diagnostic data of a vehicle.

The features described in connection with the method for transmitting diagnostic data of a vehicle and the advantages associated therewith can also be combined with the vehicle according to the invention and can in particular be implemented as a corresponding configuration of the vehicle, in particular the prefilter unit.

In particular, the prefilter unit is also designed to approximate the signal profiles of the initial data in sections by means of adaptation functions and / or to smooth the signal profiles of the initial data and / or to reduce signal noise, preferably by low-pass filtering the signal profiles. As a result, the data volume of the initial data can be further reduced, so that the data volume of the pre-filtered diagnostic data to be transmitted is reduced.

The vehicle preferably also has a memory unit which is designed to store initial data and / or pre-filtered diagnostic data. As already described above, this makes it possible, for example if there is a poor connection quality between the vehicle and the evaluation station, to retransmit the initial data and / or the pre-filtered diagnostic data at a later point in time.

Furthermore, the object of the invention is achieved by an evaluation system which has one or more vehicles of the type described above and an evaluation station, the evaluation station being designed to receive and / or store diagnostic data from the vehicles evaluate, and wherein the vehicle or vehicles is / are designed to transmit diagnostic data to the evaluation station according to the method of the type described above.

The evaluation system according to the invention has the advantages that have already been described with regard to the method for transmitting diagnostic data of a vehicle and with regard to the vehicle.

The features described in connection with the method for transmitting diagnostic data of a vehicle and the vehicle and the advantages associated therewith can also be combined with the evaluation system according to the invention and can in particular be implemented as a corresponding configuration of the evaluation system, in particular the pre-filter unit of the vehicle.

The object of the invention is also achieved by a computer-readable medium, comprising instructions which, when executed by at least one processor, cause the processor to execute the method in the manner described above.

Further embodiments emerge from the subclaims.

In the following, the invention is explained in more detail on the basis of non-limiting exemplary embodiments with reference to the accompanying drawings. Here show:

1 shows a schematic illustration of an exemplary embodiment of acquired initial data of the present invention;

2 shows a flow chart of the method steps of a

Embodiment of the method according to the invention;

3A is a schematic illustration of an embodiment of the present invention; as

3B is a schematic illustration of a further exemplary embodiment of the present invention. In FIG. 1, signal values s1, s2, s3 of three time signal curves sigl, sig2, sig3, which are included in the acquired initial data DO, for example, are mapped over time t.

In the exemplary embodiment shown in FIG. 1, the signal curve over time sigl is the (virtual) accelerator pedal angle (that is to say the accelerator pedal angle with which the driver of the vehicle can initiate a desired acceleration of the vehicle). Furthermore, the signal curve sig2 is the temporal signal curve of the torque on the crankshaft. Furthermore, the signal curve sig3 shown is the signal curve over time for the speed of the vehicle's center of gravity.

In addition, in FIG. 1, signal curve areas b are marked with dashed lines, in which redundant information is contained. While conventionally all signal values that are present in the signal curve areas b are transmitted, in the present exemplary embodiment only one signal value per signal curve area b is transmitted, since the redundant signal values are filtered out. The amount of data to be transmitted can thus be reduced without losing the information required for analyzing the vehicle condition and / or troubleshooting.

For example, various vehicle states (such as speed, torque requirement or the vehicle center of gravity) change only to a negligible extent or not at all.

In this example, a signal value for the speed of 0 km / h is transmitted at a point in time t0. Conventionally, the same signal value would now be transmitted and / or stored every 10 milliseconds, although this does not change. According to the invention, these redundant data are removed from the initial data until the signal value for the speed has changed significantly again at a point in time t1 (approaching the traffic light).

A schematic flow diagram of an exemplary embodiment is shown in FIG. 2. Step vO here represents the start of a test drive. In method step vl, initial data are recorded which include a large number of signal curves. In the next method step vl, the captured pre-filtered diagnostic data are now generated in a pre-filter step by filtering out signal values with redundant information from the multitude of signal profiles of the initial data.

This can be followed by a query step al, for example, in which it is queried whether the pre-filtered diagnostic data should be transmitted directly or whether the pre-filtered diagnostic data should first be temporarily (locally) stored in the vehicle in a storage step v4. It is also conceivable (but not shown in FIG. 2) that the query step al takes place before the prefilter step v2.

This is followed by transmission step v3, in which the pre-filtered diagnostic data are transmitted to an evaluation station. After the transfer step v3, there is a further query step a1, in which it is queried whether the test drive has ended. If the test drive is completed, the process ends. If the test drive has not yet been completed, initial data are again recorded in step vl.

3A shows a schematic illustration of an exemplary embodiment of the present invention. A vehicle 10, which is preferably moved as part of a test drive, transmits the pre-filtered diagnostic data DV, for example via a wide area connection (WAN), to the evaluation station 20 (located outside the vehicle).

FIG. 3B shows a further exemplary embodiment in which the pre-filtered diagnostic data DA, DB from two vehicles 10A, 10B are transmitted to an evaluation station 20.

Reference symbol list

10 vehicle (passenger car, truck);

20 evaluation station;

100 registration unit;

110 sensor unit (s);

120 communication unit (s);

200 pre-filter unit

300 transmission unit;

400 storage unit;

10A, 10B first vehicle, second vehicle; DA, DB pre-filtered diagnostic data of the first vehicle, diagnostic data of the second vehicle; sc (current) signal value; sp directly preceding signal value;

As signal change in value;

Asth change threshold worth; b waveform areas that contain redundant information; n predetermined number of previous signal values;

DO initial data;

DV pre-filtered diagnostic data; sl, s2, s3 signal values of the signal curves; sigl signal curve of the virtual accelerator pedal angle; sig2 Signal curve of the torque on the crankshaft; sig3 speed of the vehicle's center of gravity; t time; vO start of a test drive; vl process step in which initial data are recorded; v2 Process step in which the initial data is pre-filtered; v3 Process step in which the pre-filtered diagnostic data are transmitted to an evaluation station; v4 Process step in which the pre-filtered diagnostic data is stored in the

Vehicle are cached; as well as al, a2 query step;

Claims

EXPECTATIONS

1. A method for transmitting diagnostic data of a vehicle (10), in particular a passenger car or truck, to an evaluation station (20), the method comprising the following steps: a) Acquisition of initial data (DO) comprising a plurality of signal curves, which are generated in particular by one or more sensor units (110) and / or one or more communication units (120) of the vehicle (10); b) prefiltering the initial data (DO), with prefiltered diagnostic data (DV) being generated by filtering out signal values with redundant information from the plurality of signal curves of the initial data (DO); and c) transmitting the pre-filtered diagnostic data (DV) to the evaluation station (20).

2. The method according to claim 1, wherein during the pre-filtering of the initial data (DO) signal values (sc) are filtered out if two or more successive signal values of the signal curves remain at least essentially unchanged.

3. The method according to claim 1 or 2, wherein when pre-filtering the initial data (DO) signal values (sc) are filtered out if a signal value change (As) to the directly preceding signal value (sp) and / or to a predetermined number (n) of preceding signal values (sp) is less than a predetermined change threshold value (Asth).

4. The method according to any one of the preceding claims, wherein the pre-filtered diagnostic data (DV) are transmitted to the evaluation station (20) via a wide area connection, WAN.

5. The method according to any one of the preceding claims, wherein before and / or after the pre-filtering, the signal curves of the initial data (DO) are approximated in sections by means of adaptation functions.

6. The method according to any one of the preceding claims, wherein before and / or after the pre-filtering, the signal curves of the initial data (DO) are smoothed and / or signal noise is reduced, preferably by low-pass filtering the signal curves.

7. The method according to any one of the preceding claims, wherein the signal curves of the initial data (DO) and / or the pre-filtered diagnostic data (DV) are temporarily stored in the vehicle (10) before being transmitted to the evaluation station (20).

8. The method according to any one of the preceding claims, wherein steps a) to c) are repeated, preferably cyclically, at fixed time intervals.

9. The method according to any one of the preceding claims, in particular according to claim 3, wherein the predetermined number (n) of preceding signal values (sp) is 2 or greater, in particular greater than 5, preferably greater than 10.

10. Vehicle (10), in particular passenger car or truck, which is designed to transmit diagnostic data to an evaluation station (20), preferably according to the method according to one of the preceding claims, wherein the vehicle (10) has the following:

Acquisition unit (100), which is designed to acquire initial data (DO), which include a plurality of signal curves, which are generated in particular by one or more sensor units (110) and / or one or more communication units (120) of the vehicle (10) become;

Pre-filter unit (200) which is designed to pre-filter the initial data (DO), pre-filtered diagnostic data (DV) being generated by filtering out signal values with redundant information from the plurality of signal profiles of the initial data (DO); and Transmission unit (300) which is designed to transmit pre-filtered diagnostic data (DV) to an evaluation station (20), in particular via a wide area connection.

11. Vehicle (10), according to claim 10, wherein the pre-filter unit (200) is further designed to approximate the signal curves of the initial data (DO) in sections by means of adaptation functions and / or to smooth the signal curves of the initial data (DO) and / or to add signal noise reduce, preferably by low-pass filtering the waveforms.

12. The vehicle (10) according to claim 10 or 11, further comprising a memory unit (400) which is designed to store initial data (DO) and / or pre-filtered diagnostic data (DV).

13. Evaluation system comprising one or more vehicles (10A, 10B) according to one of claims 10 to 12 and an evaluation station (20), wherein the evaluation station (20) is designed to receive diagnostic data (DA, DB) from the vehicles (10A , 10B) to receive and to store and / or evaluate, and wherein the vehicle or vehicles (10A, 10B) is / are designed to send diagnostic data (DA, DB) to the evaluation station (20) according to the method of one of claims 1 to 9 to transfer.

14. A computer readable medium comprising instructions which, when executed by at least one processor, cause the processor to carry out the method of any one of claims 1 to 9.