DE102008015352A1 - Method for recording data and data recording system - Google Patents

Abstract

The invention relates to a method which serves for recording data which are transmitted between electronic units as bus subscribers of a bus system (1) or are generated in the bus subscribers or present there. A number of data recording modules (5) are provided, one of which is implemented in an electronics unit. Each data recording module (5) continuously encrypts data of the electronic unit in which it is implemented into a ring memory. If a trigger condition exists, data of the ring memory of the data recording modules (5) are stored. The trigger condition is when local trigger conditions on different data recording modules (5) are met.

Description

The The invention relates to a method for recording data and a Data recording system.

One such method or data recording system is used generally for recording data between electronic units be transmitted as bus subscribers of a bus system. In particular, such a bus system of a data bus of a Be formed motor vehicle. In this case, the electronics are of control units with which various vehicle functions realized or monitored formed.

Such a method for logging messages on a data bus of a motor vehicle is known from DE 103 60 125 A1 known. To carry out the method, a transmission system is provided as an external unit, which is connected via a bus interface to the data bus of the motor vehicle, which is formed by a CAN bus system. With the transmission system, a bidirectional data transmission is realized out of the vehicle and into the control devices of the vehicle. The transmission system has a controller with an executable program. The transmission system further comprises on the one hand a volatile memory in the form of a RAM (READ and ACCESS MEMORY) and a non-volatile memory in the form of a flash.

through the executable program in the transmission system be the messages that are on the data bus of the motor vehicle be exchanged, read and stored in the volatile memory, the is preferably designed as a ring memory, cached. Turns the executable program into a specific trigger event registered, the overwriting of the volatile Memory stopped then the contents of the volatile memory to transfer to the non-volatile memory. The trigger event can be from a single feature or be formed by a combination or sequence of features over the data buses are transmitted.

Based in the transmission system in this way non-volatile stored data is traceability of bus traffic achieved especially when errors occur. On the basis of non-volatile stored data can namely via the Data bus exchanged messages are tracked back, to determine from which controller connected to the data bus a faulty message was sent.

adversely Here is that the transmission system as a separate entity must be connected to the data bus of the motor vehicle, which associated with an additional design effort is.

Of the The invention has for its object to provide a method and a data recording system, by means of which with as little effort as possible safe and comprehensive control of a bus system and of this connected electronic units is made possible.

to Solution to this problem are the features of the claims 1 and 18 provided. Advantageous embodiments and expedient developments of the invention described in the subclaims.

The inventive method is used for recording of data between electronic units as bus subscribers a bus system are transmitted, and / or which in Bus participants are generated internally or are there. A number of data recording modules are provided, of which one each implemented in an electronics unit. each Data logger continuously writes electronics unit data in which it is implemented, in a ring memory. at The presence of a trigger condition becomes data of the ring buffer filed the data recording modules. The trigger condition is when local trigger conditions on different data recording modules are fulfilled.

The Storing the data may take the form of non-volatile storage the data is done. Alternatively, the filing of the data can be done first in the form of a volatile storage of the data, ensuring that this data is not overwritten become. In order to be able to save the data, these are then at a later time, especially before a power cut of the system, read to an external unit and non-volatile saved.

With the method according to the invention and the data recording system according to the invention, a comprehensive diagnostic option is possible when errors occur in the data traffic of the bus system. Since internal data of the bus subscribers are also recorded, a comprehensive diagnosis can also be carried out for them. By specifying suitable trigger conditions and storing logged data in the ring memories under fulfilled trigger conditions, the cause of the occurrence of an error can be analyzed in a targeted manner by analyzing this stored data. The trigger conditions can be selected, for example, such that these are met when specific malfunctions occur, so that then the stored data just include the period in which an error to be analyzed has occurred. The stored data then represent a relatively small amount of data to be evaluated with reasonable effort. Since the stored data are closely related to the occurrence of the error due to the specification of the trigger conditions, the cause of the error can be determined with high reliability by evaluating this data ,

The Invention is generally for automated networks with Bus systems can be used. Particularly advantageous are the inventive Method and the data recording system according to the invention for analyzing and locating faults in bus systems in motor vehicles used.

Of the The basic idea of the invention is that the data recording system for logging messages of the bus system no isolated, external unit that forms in addition to the electronic units is connected to the bus system. Rather, the data recording system forms a distributed system consisting of data recording modules, implemented in the individual electronic units of the bus system become. The fact is exploited that electronic units or control units as special electronic units in a motor vehicle, generally for use in automation systems so be interpreted that these still free computing and storage capacities exhibit. Particularly advantageous are the functionalities the data recording modules and their allocation to the electronics unit to the available free computing and storage capacities adapted, whereby on the one hand the computing and storage capacities the electronic units are optimally used and on the other hand optimizes the functionality of the data recording modules becomes.

By the inventive design of the data recording system in the form of data recording modules is no external unit for Logging the messages needed more on the bus system, whereby the hardware expenditure of the data recording system considerably is reduced. The distributed data logging system is suitable particularly advantageous for use in motor vehicles, since there additional monitoring units lack of available space and ultimately due to accumulating Additional costs generally only in prototype vehicles, not however, be accepted in standard vehicles.

The Trigger conditions are related to the design of the data logging system as a distributed system adapted so that multiple local trigger conditions, which are specified for individual data recording modules, form a trigger condition. For example, a local trigger condition is then met when for a message from a data recording module or for a particular parameter of the data logger module a certain condition is met. Generally, you can do that for all data recording modules or only for a subset of data recording modules such a local Trigger condition to be defined. The definition of such local Trigger conditions preferably occur in an initialization phase an external unit, in particular in an analysis unit, the also for measured value evaluation, that is for error analysis, is used. This external unit must only during the initialization phase are connected to the bus system, but not during its operation.

For checking, whether the or a trigger condition is met, replace the data recording modules via the bus system with each other a reserved message. In this one shares a data recording module the other data logger module if its local trigger condition is satisfied. The trigger condition is fulfilled if in the reserved message the messages of all data recording modules, that their local trigger conditions are met are.

The trigger conditions formed from the local trigger conditions can participate in the training of data recording modules in be optimally adapted, thereby achieving that Trigger conditions fulfilled in specific error functions are, so that then selectively filed at the error times data can then be based on these data, the emergence and analyze causes of errors.

Of the Scope of the data that can be stored, can be advantageous from be dependent on the trigger conditions, whereby for specific error situations needed for error analysis Data can be optimally selected.

The Storing the data, in particular their non-volatile storage can be flexibly adapted to the conditions of the bus system. Depending on available memory and computing capacity the individual electronic units of the bus system can be stored of the data locally in the memories of the electronic units in which the data recording modules are integrated done. Alternatively, you can a powerful electronic unit for central storage all data are used.

In the data recording system according to the invention is advantageously an external unit in the form of an analysis unit only for initialization of Trigger condition and to evaluate the stored data needed. Both functions are time independent of the data logging with the data recording modules and can therefore be performed independently of these at freely selectable times.

The Invention will be described below with reference to an embodiment and explained with reference to the drawing. It shows:

1 : Schematic representation of an embodiment of the data recording system according to the invention.

1 schematically shows a bus system 1 within a motor vehicle to which multiple control devices 2 are connected, which generally form electronic units and as a bus subscriber via the bus system 1 exchange data by sending messages.

Such a bus system 1 A motor vehicle may generally also comprise a configuration of a plurality of data buses, with CAN buses and LIN buses typically being used in motor vehicles. The controllers 2 of the motor vehicle form, for example, units for providing or monitoring vehicle functions. Example of this are control units 2 for the brake, clutch or steering of a motor vehicle.

This in 1 illustrated bus system 1 is shown greatly simplified and shows a predetermined number of control units 2 via bus lines 3 connected to each other. Each control unit 2 has a bus interface 4 for connection to the bus system 1 on.

Such controllers 2 generally form electronic units with at least one computer unit and storage media for storing data. In this case, preferably, each control unit 2 In addition to at least one volatile memory such as a RAM and at least one non-volatile memory such as a flash or EEPROM. If with the control units 2 safety-relevant functions are executed, they may have a redundant structure to achieve the necessary error safety.

The controllers 2 used in a motor vehicle are generally designed so that they have free computing and storage capacities.

These free capacities of the control units 2 are exploited by the fact that in this data recording modules 5 be implemented. This in the control unit 2 integrated data recording modules 5 form components of a distributed data recording system. As other components of the data recording system is as external to the bus system 1 connectable unit an analysis unit 6 provided, which is generally formed by a computer unit and a bus interface 4 for connection. The analysis unit 6 is not permanent, but only at certain times to the bus system 1 connected, which is indicated by the dashed lines of the analyzer 6 to the bus system 1 is indicated.

The in the individual control units 2 implemented data recording modules 5 form software modules that control the computing and storage capacities of each control device 2 use. In particular, each data recording module uses 5 the free capacity of the non-volatile memory of the controller 2 on which this is integrated to form a ring buffer. In this ring memory are continuously data of the associated control unit 2 , in particular from this sent or received messages, non-volatile stored.

The size of the ring buffer is the free storage capacity of the associated control unit 2 customized. In the implementation, the individual data recording modules 5 this in a suitable manner to the control units 2 divided and specified in a suitable manner in terms of their functionality.

The logging of messages of the individual control units 2 through the data recording modules implemented in them 5 serves to error in the individual control units 2 or in the transmission of messages via the bus system 1 to recognize and analyze. To get as comprehensive an analysis as possible in each control unit 2 a data recording module 5 be implemented. Generally speaking, only in a given part of the control units 2 Record Module 5 be integrated.

The operation of the distributed data recording system is such that during operation of the bus system 1 the individual data recording modules 5 the data of the assigned ECUs 2 , in particular the sent and received messages, continuously read and inscribed in the ring buffer. If a predefined trigger condition is fulfilled, data of the ring buffer are not stored volatile. In general, the non-volatile storage of the data can be done locally by the data of the ring memory of the data recording module 5 in the non-volatile memory of the controller 2 in which this data recording module 5 is implemented, stored. Alternatively is also one central storage possible by, for example, the data of the ring memory of all data recording modules 5 in the non-volatile memory of a controller 2 be stored.

The non-volatile storage of data can be the easiest Case such that at the time of fulfillment the trigger condition does not contain the entire contents of a ring buffer is stored volatile. Alternatively, the non-volatile storage be done such that the data of the ring memory of a defined Time before fulfillment of the trigger condition up to one defined time after fulfillment of the trigger condition be transferred to the non-volatile memory. As a general rule can the amount of non-volatile data be dependent on the respective trigger condition.

The definition of the type and scope of the non-volatile storage and the definition of the trigger condition takes place during an initialization phase via an external unit, preferably the analysis unit 6 , During this initialization phase, but not during the subsequent operation of the bus system 1 , is the analysis unit 6 to the bus system 1 connected.

The trigger conditions are adapted to the distributed structure of the data logging system and are each of a number of local triggering conditions for individual data logging modules 5 educated. Each local trigger condition for a data recorder module 5 defines a setpoint for a particular variable or parameter in the controller 2 itself, in which the data recording module 5 is integrated, or in a message, by this control unit 2 received or sent. In general, such a trigger condition can be defined by that for all or only part of the data recording modules 5 local trigger conditions are given.

During the operation of the bus system following the initialization phase 1 the check is made as to whether a trigger condition is met such that the data recording modules 5 exchange with each other a reserved message, in which a data recording module 5 the other data recording module 5 tells if its local trigger condition is met. In general, this reserved message consists of individual trigger fields for the individual local trigger conditions. In each case, a trigger field is set if the corresponding local trigger condition is fulfilled. The entire trigger condition is fulfilled when all the trigger fields are set, that is, when in the reserved message the messages of all data recording modules 5 that their local trigger conditions are met, are included. If several trigger conditions are specified, a reserved message with a corresponding number of trigger fields can be exchanged for each of these trigger conditions.

The trigger conditions are generally chosen so that they are adapted to certain types of errors, so that the trigger conditions are met in certain error situations. Furthermore, since the nature and extent of the non-volatile stored data are adapted to the trigger conditions, they provide immediate information about any errors that may have occurred in the control units 2 or in the over the bus system 1 sent messages.

The evaluation of the non-volatile data is carried out in the analysis unit 6 , For this purpose, the analysis unit 6 at a given time to the bus system 1 be connected to the motor vehicle. For example, it can be detected while driving a motor vehicle with a counter, how often a trigger condition has been met. Was a certain number of trigger conditions met, that is, a certain number of error situations was detected, it can be issued to the driver of the motor vehicle a message that he should visit a workshop. There then becomes the analysis unit 6 to the bus system 1 connected to the motor vehicle and it will be the non-volatile stored data of the individual data recording modules 5 read out and evaluated. A defined temporal reference of messages from different data recording modules 5 can be established by the timing of sending messages between the data recording modules 5 is traced back. For example, a chronological sequence of messages is obtained by analyzing which messages form responses or responses to previous messages. In general, a chronological sequence of messages can be obtained by providing them with unique time stamps. From the non-volatile stored data to a trigger condition results in a complete image of the traffic between the control units 2 in exactly the time range in which the error occurred. This is because the trigger time corresponds to the time the error occurred and the data is recorded in a time range around this trigger time. This allows a precise analysis of the error that has occurred.

1

bus system

2

control unit

3

bus line

4

bus interface

5

Data recording module

6

analysis unit

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 10360125 A1 [0003]

Claims (23)

Method for recording data which is transmitted between electronic units as bus subscribers of a bus system and / or which are internally generated or present in bus subscribers, characterized in that a number of data recording modules ( 5 each of which is implemented in an electronics unit, each data recording module ( 5 ) continuously encrypts data of the electronic unit in which it is implemented into a ring memory, and that in the presence of a trigger condition data of the ring memory of the data recording modules ( 5 ), where the trigger condition exists when local trigger conditions on different data recording modules ( 5 ) are met. Method according to claim 1, characterized in that the data recording modules ( 5 ) are formed by software modules. Method according to one of claims 1 or 2, characterized in that the data recording modules ( 5 ) use free computing and storage capacities of the electronics unit. Method according to one of claims 1 or 2, characterized in that the formation of the data recording modules ( 5 ) as well as their divisions are adapted to the electronic unit to the free computing and storage capacities. Method according to one of claims 1 to 4, characterized in that one or more trigger conditions be specified by an external unit. A method according to claim 5, characterized in that the external unit from one to the bus system ( 1 ) connectable analysis unit ( 6 ) is formed. A method according to claim 6, characterized in that for the specification of the trigger conditions of the analysis unit ( 6 ) local trigger conditions into the data recording modules ( 5 ). Method according to one of claims 1 to 7, characterized in that to check whether the or a trigger condition is met, the data recording modules ( 5 ) via the bus system ( 1 ) exchange a reserved message with each other, in which a data recording module ( 5 ) the other data recording modules ( 5 ) if its local trigger condition is met. A method according to claim 8, characterized in that the trigger condition is satisfied if in the reserved message the messages of all data recording modules ( 5 ) that their local trigger conditions are met are included. Method according to one of claims 1 to 9, characterized in that all data of the ring memory be filed. Method according to one of claims 1 to 9, characterized in that in the presence of or a trigger condition stored data depends on this trigger condition. Method according to one of claims 1 to 11, characterized in that data of the ring memory, in a predetermined time interval are stored, the beginning the time interval a defined time before the time of the trigger conditions and where the end of the time interval is a defined time after the time of the trigger condition. Method according to one of claims 1 to 12, characterized in that in the presence of a trigger condition stored data is not stored volatile. A method according to claim 13, characterized in that the non-volatile storage of data of the ring memory of a data recording module ( 5 ) locally. A method according to claim 14, characterized in that for the non-volatile storage of data of the data recording module ( 5 ) a non-volatile memory of the electronics unit, in which the data recording module ( 5 ) is used. A method according to claim 13, characterized in that the non-volatile storage of data of the ring memory of a data recording module ( 5 ) centrally. Method according to Claim 16, characterized in that the data of the ring memories of the data recording modules ( 5 ) are stored centrally in an electronics unit non-volatile. Method according to one of claims 1 to 12, characterized in that in the presence of a trigger condition stored data is not stored first and non-volatile at a later date get saved. A method according to claim 18, characterized in that the stored data for non-volatile storage to an external unit via wear. Method according to one of claims 6 to 19, characterized in that in the analysis unit ( 6 ) an evaluation of the stored data takes place. Data recording system for recording data which is stored between electronic units as bus subscribers of a bus system ( 1 ), characterized in that a number of data recording modules ( 5 ), wherein in each case a data recording module ( 5 ) is implemented in an electronics unit, each data recording module ( 5 ) has a ring memory, in which continuously encrypts data of the electronic unit in which this is implemented, and that in the presence of a trigger condition data of the ring memory of the data recording modules ( 5 ) are stored in at least one memory, wherein the trigger condition is present when local trigger conditions on different data recording modules ( 5 ) are met. Data recording system according to claim 21, characterized in that data are stored therewith which are transmitted via a bus system ( 1 ) of a motor vehicle. A data recording system according to claim 22, characterized characterized in that the electronic unit control devices of a motor vehicle.