DE102005016323B4 - Method for the synchronization of measured data - Google Patents

Abstract

Method for the synchronization of measurement data for measuring the driving dynamics of motor vehicles with a plurality of control devices (2), which are connected to one another via a data transmission system (1) and at least one measuring computer (4a, 4b) for receiving and storing data to the data transmission system (1) and / or to at least one control unit (2) is connected, wherein the method comprises the following steps: - Operating a motor vehicle and the data transmission system (1) with at least one control unit (2) and / or a measuring device (3) and at least a measuring computer (4a, 4b), - recording and storing a first data set from a first data source, wherein the data source is the data transmission system (1) and / or a control unit (2), - recording and storing at least one further data set from at least one other Data source, wherein the data source, the data transmission system (1) and / or a control unit ( 2), applying a correlation to the first and at least one further data set to calculate a time offset (Δt) of the respective signal sequence of the at least two data sets. - Shifting one of the two data sets by the determined time offset (.DELTA.t) in order to achieve a synchronization of the data sets and / or a Nachabtastung the data set in the sense of an over- or undersampling apply, the measurement data are detected in the motor vehicle and as a data transmission system (1 ) an in-vehicle CAN bus is used.

Description

The invention relates to a method for the synchronization of measurement data, in particular for measuring the driving dynamics of motor vehicles, with a plurality of control devices, which are interconnected via a data transmission system and at least one measuring computer for receiving and storing data to the data transmission system and / or at least one control unit and / or is connected to at least one measuring device.

Such systems are known in particular for the validation of simulation models. Extensive vehicle dynamics measurement data are recorded with computer systems, whereby the recording of the measurement data is carried out during test operation of the vehicles. In particular, the measurement data to be recorded includes signals from electronic safety and auxiliary systems such as the ESP Electronic Stability Program, the ABS Anti-lock Braking System, ASR Traction Control, or similar vehicle dynamics systems which act as active safety devices in a vehicle driver relieve stress especially in extreme situations and thus be used to increase driving safety.

For structural design of the mechanical and electronic systems or, for example, the interpretation and the later programming control settings of control units simulation models are used, which reflect the real situations of the operation of the motor vehicle as accurately as possible.

Such methods for achieving a high quality statement of simulation models are well known. Extensive vehicle dynamic measurement data are recorded in the real test and then compared via an invoice / measurement comparison in order to determine the validity of the simulation models. The recording of the measured data takes place via measuring devices which are either present in the vehicle or installed in the motor vehicle for the purpose of measurement. The data source can thus be either an in-vehicle data transmission system, wherein the reading and recording of the data can also be done on the control unit itself, or the measuring devices installed in the vehicle provide the data on the driving dynamics of the motor vehicle. After recording and storing the vehicle dynamics-relevant measurement data, the statement quality of the simulation models can be determined based on an invoice / measurement comparison.

In the overall system of a vehicle, a large number of vehicle dynamics-relevant signals are made available by the control units and measuring systems which are installed for the duration of the measurements in the motor vehicle. In order to achieve a high level of statement quality about the simulation models, it is necessary to record the given measurement data as completely as possible.

In this known method, the problem arises that no available measuring system can completely record all data. This is particularly due to the fact that the amount of signals to be recorded depends on the transmission rate of the measuring devices and is thus limited. Due to the limited possibilities of data acquisition, the informative quality of the simulation models can not be fully determined since the maximum transmission rate of the measuring systems represents the limiting factor of the overall system.

The EP 1 347 356 A2 discloses a system with multiple devices, each one clock "clock" and buffer "event buffer" for storing a data value, with a synchronized time is sought in the clocks.

The US 2003/0014680 discloses a method for synchronizing data exchange between a data source and a controller.

It is therefore the object of the present invention to provide a method for the synchronization of measurement data, with which a limited amount of output measurement data can be recorded, stored and evaluated with the established measurement systems, whereby a comprehensive high-quality data set for determining the statement quality of the simulation models is made available.

This object is achieved on the basis of a method for the synchronization of measured data according to the preamble of claim 1 in conjunction with its characterizing features and of a device according to claim 8. Advantageous developments of the invention are specified in the dependent claims.

• – Betreiben des Kraftfahrzeugs und des Datenübertragungssystems mit mindestens einem Steuergerät und mindestens einem Messrechner,
• – Aufnahme und Speicherung eines Datensatzes aus einer ersten Datenquelle, wobei die Datenquelle das Datenübertragungssystem und/oder ein Steuergerät ist,
• – Aufnahme und Speicherung mindestens eines weiteren Datensatzes aus mindestens einer weiteren Datenquelle, wobei die Datenquelle das Datenübertragungssystem und/oder ein Steuergerät ist,
• – Anwendung einer Korrelation auf den ersten und auf mindestens einen weiteren Datensatz, um einen Zeitversatz (Δt) der jeweiligen Signalfolge der mindestens zwei Datensätze zu berechnen.
• – Verschiebung eines der beiden Datensätze um den ermittelten Zeitversatz (Δt), um eine Synchronisation der Datensätze zu erzielen und/oder eine Nachabtastung des Datensatzes im Sinne einer Über- und/oder Unterabtastung anzuwenden.

The invention includes the technical teaching that the method for the synchronization of measured data comprises the following steps:

• Operating the motor vehicle and the data transmission system with at least one control device and at least one measuring computer,
• Recording and storing a data record from a first data source, wherein the data source is the data transmission system and / or a control unit,
• Recording and storing at least one further data record from at least one further data source, wherein the data source is the data transmission system and / or a control unit,
• Applying a correlation to the first and at least one further data set in order to calculate a time offset (Δt) of the respective signal sequence of the at least two data sets.
• - Shifting one of the two data sets by the determined time offset (.DELTA.t) in order to achieve a synchronization of the data sets and / or to apply a Nachabtastung the record in the sense of an over- and / or undersampling.

The measured data are recorded in the motor vehicle and an in-vehicle CAN bus is used as a data transmission system.

This solution has the advantage that the determination of a time offset (Δt) enables a correlation with which other data sets can be correlated at the same time. Thus, a measurement computer can acquire and store multiple data sets from a measurement system triggered by an internal sampling system. With a one-time determination of a time offset thus all other records can be time correlated. Such a variety of data sets can provide a single measurement system to obtain the most comprehensive data that is not available with systems that are installed in the car as standard. These individual data records thus obtained are already time-synchronized due to common triggering, so that all the other data records supplied by the measuring system without a respective individual correlation can also be correlated with the correlation of only one individual data record. The sampling rate of the measurements may be in the range of 10 ns to 1 s, preferably in the range of 100 ns to 100 ms and particularly preferably in the range of 1 ms to 10 ms.

If the data sets to be correlated have different time ranges, resampling may be used in the correlation of the data sets in the sense of an over- or undersampling, in order to equalize the time ranges of the data records and thus create the prerequisite for a complete synchronization. The correlation in the sense of the present invention comprises a cross-correlation. In this case, a multiplicity, but at least two, matching measured values are determined from each of the at least two data sets in order subsequently to determine a time offset (Δt) between the two measured values. Moreover, if the respective data records do not also have the same time periods in terms of time, a resampling is performed. The individual measured values considered for the correlation can be present both as a starting value of the individual data record or at any point within the individual data record.

A further measure improving the invention provides that each measured value is assigned to a time of measurement also recorded with the measurement. Advantageously, a time offset (Δt) can be calculated via such an assignment of the time of measurement of the individual measured value. The storage of the data records is preferably carried out in tabular form, wherein a data line comprises both the at least one measured value and the time information, so that the at least one measured value can be assigned to the data record.

Advantageously, each further recorded data record is likewise shifted by the time offset (Δt). Thus, it is sufficient that all other data sets, which were taken from a closed-loop measuring system by the measuring computer, with a one-time determined time offset (.DELTA.t) are correlated. Advantageously, a networking of different autonomous measuring systems can thus be carried out without a hardware outlay.

For procedural reasons, it is of particular advantage that the first and at least one further data record are brought into a uniform data format. Only so can a correlation be made since the at least two datasets can be represented in a software application such as Matlab and preferably Matalb 13.1, The MathWorks, Inc., 3 Apple Hill Drive, MA 01760-2098USA.

In one embodiment, a measuring device is further installed in the vehicle. Advantageously, the measuring device installed in the vehicle is an inertial system, which comprises at least one acceleration sensor, with which an acceleration of the motor vehicle in at least one degree of freedom in space is detected. These inertial systems may be constructed of accelerometers and adapted for transversal movements or accelerations or rotational movements and / or accelerations such as yawing, pitching or rolling and installed next to the data transmission system in a motor vehicle. In addition, a signal transmitter, such as a sensor of an inertial system installed for the purpose of the measurement, can be electrically coupled to the data transmission system which is permanently installed in the vehicle.

The data transmission system is an in-vehicle CAN bus. The in-vehicle CAN bus networks a large number of individual control units with each other. Thus, in particular, the data of interest for the driving dynamics of the motor vehicle can be called up via the CAN bus. The measuring computer, which may be designed as a laptop for mobile measurement applications present here, is connected to the CAN bus in order to record the corresponding data.

Advantageously, the at least one control device of the motor vehicle is used to control an electronic stability program (ESP) or to control an anti-lock braking system (ABS). In addition to the particularly relevant for the driving dynamics of the motor vehicle control units data from other control devices such as engine control unit, transmission control unit or damper control unit can be detected.

An apparatus for recording and synchronizing measurement data for measuring vehicle dynamics is also provided, comprising the following features: a motor vehicle having a plurality of control devices ( 2 ), which via a data transmission system ( 1 ), at least one measuring computer ( 4a . 4b ) for receiving and storing data which is sent to the data transmission system ( 1 ) and / or to at least one control device ( 2 ) connected. In the at least one measuring computer ( 4a . 4b ) a first data set from a first data source and a further data record from at least one other data source are recorded and stored, wherein the data source is the data transmission system ( 1 ) and / or a control device ( 2 ). A correlation is applied to the first and at least one further data record in order to calculate a time offset (Δt) of the respective signal sequence of the at least two data sets. One of the two data sets is shifted by the determined time offset (.DELTA.t) in order to achieve a synchronization of the data sets and / or a Nachabtastung of the data set in the sense of an over- or undersampling is applied. The measured data are recorded in the motor vehicle and used as a data transmission system ( 1 ) an in-vehicle CAN bus is used.

Further measures improving the invention are specified in the subclaims or will be described in more detail below together with the description of a preferred embodiment of the invention with reference to FIG. The only figure shows:
A schematic representation of a measurement setup for recording driving dynamics relevant data sets.

In the 1 is a schematic representation of the measurement setup shown, with which the detection of the vehicle dynamics relevant measurement data takes place. The data transmission system 1 is a CAN bus and is indicated as a horizontal line. The data transmission system 1 networks in the illustrated case by way of example three control units 2 with each other, so these over the data transmission system 1 Can exchange data with each other. The controllers 2 are permanently installed in the motor vehicle, so their connection to the data transmission system 1 represented by a solid line. About a measuring computer 4a become the data transmission system 1 transmitted data such as control signals of the control units 2 captured and saved. About another measuring computer 4b In addition, data is transferred directly from a control unit 2 captured and saved.

For the purpose of the driving dynamics measurement in the real test is a measuring device 3 to the data transmission system 1 connected, the non-permanent connection is represented by a dashed line. The schematically illustrated measuring device 3 is in the present embodiment, an inertial system, which detects acceleration sensors for detecting movements or accelerations of the motor vehicle in the degrees of freedom possible in space. The over the measuring device 3 Data output is from a measuring computer 4c captured and saved. In the case of six possible degrees of freedom in space, the detection of six data sets is possible, the cross-correlation of only one data set being sufficient, all the remaining ones with a measuring device 3 related data.

The invention is not limited in its execution to the embodiment given above. There are a plurality of variants conceivable, which makes use of the illustrated solution even with fundamentally different types.

LIST OF REFERENCE NUMBERS

1

Data transfer system

2

control unit

3

measuring device

4a, 4b, 4a

measuring computer

(At)

time offset

Claims (8)

Method for the synchronization of measured data for measuring the driving dynamics of motor vehicles with a plurality of control devices ( 2 ), which via a data transmission system ( 1 ) and at least one measuring computer ( 4a . 4b ) for receiving and storing data to the data transmission system ( 1 ) and / or to at least one control device ( 2 ), the method comprising the following steps: - operating a motor vehicle and the data transmission system ( 1 ) with at least one Control unit ( 2 ) and / or a measuring device ( 3 ) and at least one measuring computer ( 4a . 4b ), - recording and storing a first data set from a first data source, wherein the data source is the data transmission system ( 1 ) and / or a control device ( 2 ), - receiving and storing at least one further data record from at least one further data source, wherein the data source is the data transmission system ( 1 ) and / or a control device ( 2 ), applying a correlation to the first and at least one further data set to calculate a time offset (Δt) of the respective signal sequence of the at least two data sets. Shift of one of the two data sets by the determined time offset (Δt) in order to achieve a synchronization of the data sets and / or to apply an afterscan of the data set in the sense of an over- or undersampling, wherein the measurement data are recorded in the motor vehicle and used as a data transmission system ( 1 ) an in-vehicle CAN bus is used. A method according to claim 1, characterized in that each measured value is assigned to a likewise detected with the measurement time of the measurement. A method according to claim 1 or 2, characterized in that each further recorded data set is also shifted by the time offset (Δt). A method according to claim 1 or 2, characterized in that the first and at least one further data set are brought into a uniform data format. A method according to claim 1, characterized in that further comprises a measuring device installed in the vehicle ( 3 ), which is implemented as an inertial system, which comprises at least one acceleration sensor with which an acceleration of the motor vehicle in at least one degree of freedom in space is detected. Method according to claim 1, characterized in that the at least one control unit ( 2 ) of the motor vehicle is used to control an electronic stability program (ESP). Method according to claim 1, characterized in that the at least one control unit ( 2 ) of the motor vehicle is used to control an anti-lock braking system (ABS). Device for recording and synchronization of measured data for the measurement of driving dynamics comprising: - a motor vehicle with a plurality of control devices ( 2 ), which via a data transmission system ( 1 ), at least one measuring computer ( 4a . 4b ) for receiving and storing data which is sent to the data transmission system ( 1 ) and / or to at least one control device ( 2 ) is connected, wherein in the at least one measuring computer ( 4a . 4b ) a first data record from a first data source and a further data record from at least one other data source are recorded and stored, wherein the data source is the data transmission system ( 1 ) and / or a control device ( 2 ), wherein a correlation is applied to the first and at least one further data record in order to calculate a time offset (Δt) of the respective signal sequence of the at least two data records, wherein one of the two data records is shifted by the determined time offset (Δt) to achieve a synchronization of the data records and / or a Nachabtastung of the data set in the sense of an over- or undersampling is applied, wherein the measurement data are detected in the motor vehicle and as a data transmission system ( 1 ) an in-vehicle CAN bus is used.

Images