DE10213895A1 - Diagnosis module for a motor-vehicle on-board diagnosis system represents system components in a functional hierarchy with the components linked using combinational logic operators and a configuration table - Google Patents

Abstract

Diagnosis module for the on-board diagnosis of a mechatronic motor vehicle system with a system diagnosis module (10) that represents the system components in a functional hierarchy, whereby the components are linked by AND, inclusive OR or NOT operations. Linking of the hierarchy functional elements can also be achieved using Exclusive OR, equivalence or more than functions. Said diagnosis module uses a configuration table with which functional elements are activated or deactivated. The invention also relates to a corresponding system diagnosis method.

Description

The invention relates to a diagnostic module, in particular for the On-board diagnostics of a mechatronic vehicle system, with a system diagnostic model that includes components of the system in a component hierarchy and the functions of the system in depicts a functional hierarchy, where elements of the Component hierarchy using conjunctions and elements of the Functional hierarchy using conjunctions, disjunctions or Negations, antiquities, equivalences and / or more-than-n Functions are linked. The invention also relates to a System diagnostic procedure, especially for on-board Diagnosis of a mechatronic vehicle system, by means of a inventive diagnostic module.

From the published dissertation Heinzelmann, A., Product Integrated Diagnosis of Complex Mobile Systems, Dusseldorf, VDI-Verlag 1999 , a diagnostic module for the on-board diagnosis of a mechatronic vehicle system is known, which uses a system diagnostic model in which components of the system in a component hierarchy and the functions of the system are mapped into a functional hierarchy. Elements of the component hierarchy are linked by means of conjunctions and elements of the function hierarchy by means of conjunctions, disjunctions or negations, antivalencies, equivalences and / or more-than-n functions. The component hierarchy and the function hierarchy are interconnected at the lowest level. Each modification of the vehicle system depicted in the functional and component hierarchy requires a specific functional and component hierarchy. By means of conjunctions, subfunctions in the function hierarchy are associated with an associated hyperfunction, so that all conjunctively connected subfunctions always come into consideration for the failure of the hyperfunction. The disjunctive connection elements are used to describe redundant systems in safety-critical areas. The negation accounts for the failure of a function or component. Between two functions, there may be one or more connection operations that represent the logical dependencies between the over- and under-functions. The mapping of complex logical relationships requires a complex structure of the functional hierarchy.

From European patent application EP 0 482 523 A2 a user interface for a diagnostic system is known based on a hierarchical model. The hierarchical Model includes on the one hand a component hierarchy and on the other hand, a functional hierarchy.

From the German patent DE 197 42 448 C1 is a Diagnostic module for creating a diagnosis for electrical controllable systems known. Contains another diagnostic module a graph consisting of two subgraphs, the first Subgraph the structure of the components and the second Subgraph the relationships between the overall system functions and represents the functions of the individual components. The Graphs are hierarchical. The knots of Partial graph representing a component hierarchy is each connected to a conjunctive link. The knots the second subgraph, which forms a functional hierarchy, are by conjunctions, disjunctions and / or negations connected.

With the invention, a diagnostic module and a System diagnostic procedures are created, with which the representation or the diagnosis of real systems is simplified.

According to the invention, this is a diagnostic module, in particular for the on-board diagnosis of a mechatronic vehicle system, with a system diagnostic model that includes components of the system a component hierarchy and the functions of the system in depicts a functional hierarchy, where elements of the Component hierarchy using conjunctions and elements of the Function hierarchy using conjunctions, disjunctions and / or Negations are linked, provided, for linking of the elements of the functional hierarchy also antivalences, Equivalences and / or more-than-n functions are used.

By using antivalents, equivalences and more than n functions will be better imaging capabilities for real Systems created, for example, for logical Component functions, by means of conjunctions, disjunctions and / or negations not or only with increased Modeling effort can be displayed. An antivalence or an exclusive OR then has an active output if an odd one Number of input functions in the active state. Equivalences will then have an active state if all Inputs have the same state. Has a more than-n function only an active initial state if at least one fixed number of input states is active. For example, a more than 1 function has an active one only Output state when an input state or more than an input state is active.

In a further development of the invention is a configuration table provided by means of the individual elements of the functional and Component hierarchy selectively activated or deactivated can be.

In this way, minor deviations or Modifications of a real system with one and the same System diagnostic model. For example, at Optional equipment of a vehicle system individual elements of the Function and component hierarchy selectively activated or disabled. The configuration table is at each Processing step during the creation of a system diagnosis included.

In development of the invention is storage space for dynamic inference data during the execution a system diagnostics arise as variable data, provided, and there are means to take into account the dynamic Conclusion data while performing a System diagnostics provided.

For example, conclusions can be made from a first Pass are stored, being in the first pass starting from a defective system function a causative Component is determined. The conclusions of the first Passing can then be done on a second pass be taken into account in the example starting from a defective component an impaired function is determined. This is advantageous especially in complex Impairments caused by failure of multiple components and / or Functions can be caused and under which different polluters must be selected.

The problem underlying the invention is also by a system diagnostic procedure, in particular for the on-board Diagnosis of a mechatronic vehicle system, by means of a solved diagnostic module according to the invention, in which a means a configuration table is set to activated or deactivated state of elements of the functional and Component hierarchy when performing the system diagnostics is taken into account.

In an embodiment of the invention are in the system diagnostic method according to the invention dynamic inference data stored while performing a System diagnostics arise as variable data, and the dynamic Conclusion data will be used when carrying out the System diagnostics taken into account.

Other features and advantages of the invention will become apparent the claims and the following description of a preferred embodiment of the invention in connection with the Drawing. In the drawing show:

Fig. 1 is a schematic diagram for explaining the system diagnosing method of the invention using a diagnostic module of the invention, and

Fig. 2 is an illustration of a system diagnostic model for the novel diagnostic module.

In the illustration of FIG. 2, a system diagnostic model 10 is shown by way of example, which consists of a component hierarchy 12 and a function hierarchy 14 . The component hierarchy contains the components installed in the system as nodes that are displayed in a rectangle. For each node is the information as to whether the corresponding component represents a smallest exchangeable unit. This should indicate to the service technician that the corresponding component is exchangeable in the event of an error. In addition, an attribute of the node indicates whether it constitutes a superset. This allows the user to better structure the components. For example, the majority of the automation devices include all control devices. The connection of the components with each other is carried out with a conjunction or conjunctive link, since the individual components are each unique to a super-component. The direction of the edges between components always points to the level above. For example, the components 22 , 24 , 26 , 28, and 30 are uniquely associated with the overcomponent 18 , and the direction of the conjunctive linkages points from the components 22 , 24 , 26 , 28, and 30, respectively, to the parent component 18 .

In the functional hierarchy 14 , the functions of a system to be described are represented as nodes in the form of ovals, the functions being arranged on different levels. Each node element that represents a system function contains as attribute the output level and the criticality. The output level is used to distinguish error messages for the various user groups, for example the user or the service technician. The severity of an error reflects the criticality that serves to prioritize messages for a display unit. The criticality consists of a discrete number. In addition to the functions, the function hierarchy includes connection operations. Conjunctions, disjunctions, negations, antivalencies, equivalences, and / or more than n functions may be used as linking operations to join functions. For example, the functions 32 and 34 are linked by means of a conjunction 54 , just as the functions 36 , 38 and 34 are also linked by means of a conjunction 56 . Disjunctions can also be used to connect functions; this is illustrated by the example of the combination of the functions 38 , 58 and 60 by means of the disjunction 62 . An exclusive OR 64 is provided in the functional hierarchy 14 for connecting the functions 40 , 44 , 46 and 48 . The functions 42 , 48 , 50 and 52 are connected by means of an equivalency 66 . The functions 58 , 68 , 70 and 72 are connected by means of a more than-n function 74 . The connection operations 54 , 56 , 62 , 64 , 66 and 74 of FIG. 2 are shown by way of example only.

Disjunctions (OR links) are used to describe redundant systems in safety-critical areas. A negation, not shown in FIG. 2, responds to the failure of a function or component. A function that results from an exclusive-OR operation is active if and only if an odd number of input functions occupy an active state. An equivalence has an active output state if all input functions have the same state. An over-n function has an active output state only if the set number of input states includes the active value, for example, the output state of a more than 1 function is active when at least one input state is active.

In order to draw conclusions by means of the system diagnostic model 10 shown in FIG. 2, the information contained in the system diagnostic model 10 can be used in different ways. One possibility is to determine the respective impaired functions in the corresponding level from a defective component. Another evaluation assumes a defective system function and closes on the causative components. Likewise, these two possibilities can be combined. In each case, a predetermined number of defective components and unusual functions is known and from this all unknown component or functional states are determined by means of the system diagnostic model 10 . In the case of a malfunction or a component failure, the hierarchical structure can be used to determine the smallest exchangeable unit belonging to a faulty component.

Conclusion in the hierarchical system diagnostic model 10 requires dynamic data containing the current states of the individual components and functions. Each component or function of the system diagnostic model 10 can each assume three states:
active: the component or function has no error;
active-inactive: the state is unknown;
inactive: the component or function is faulty.

Depending on the direction in which the system diagnostic model 10 is traversed, either input-output relations or output-input relations of the components of the system diagnostic model 10 must be taken into account.

In order to conclude initial states from known input states with the aforementioned connection operations, the input-output relations listed in the following table apply. The relationships each describe an output value of a connection operation with one input state or two input states. For the negation only the input state I _{1 is} to be considered.

In order to allow a conclusion from a higher level to a lower level by means of the system diagnostic model 10 , the corresponding output input relations given in the following table must be taken into account.

Based on the relations given in the above tables, faulty components, faulty functions and / or an associated smallest exchangeable unit can be determined by means of the system diagnostic model 10 .

The system diagnosis method according to the invention will now be explained with reference to the illustration of FIG . In Fig. 1, the function and component hierarchy of Fig. 2 is also designated by the reference numeral 10 . In addition to the function and component hierarchy 10 , a configuration table 80 is available as database. The configuration table 80 stores which elements of the function and component hierarchy 10 are individually deactivated. Basically, all elements of the system diagnostic model 10 are activated. In order to be able to handle minor modifications of the system with the same system diagnostic model 10 , it can be determined by means of an entry in the configuration table 80 that a corresponding element of the system diagnostic model 10 is not taken into account. In this way, for example, optional equipment can be treated with the same system diagnostic model. The configuration table 80 is queried as it passes through the system diagnostic model 10 at each level.

In addition, the database contains dynamic inference data 82 . Herein, variable data that arises during the analysis is cached. Also, this dynamic inference data is taken into account when going through the system diagnostic model 10 at each level. In this way, the results of several runs can be combined or conclusions drawn at one level of the system diagnostic model 10 can also be taken into account for further levels.

In the illustration of FIG. 1, the various diagnostic options that the diagnostic module according to the invention offers are shown. Thus, block 84 illustrates the determination of faulty functions, block 86 the determination of suspect components, and block 88 the determination of a smallest interchangeable unit.

The search for erroneous functions in block 84 requires as input data a component state with the output level, the output level being used to distinguish error messages for the different user groups, for example the user or the service technician.

Taking this input data into consideration, the system diagnostic model 10 is run downwards starting from the component 16 in FIG. 2, whereby the functional states in the lowest level of the functional hierarchy, in FIG. 2 the functional states of the function 32 , are determined by means of a search method. Subsequently, by means of the diagnostic method in the system diagnostic model 10 in the direction of the edges, that is, in the direction of the arrows shown in FIG. 2, all functions are determined which have the state inactive with the previously defined output level. The error state of the elements of the function hierarchy 14 results from the table of input-output relations given above. The determined function nodes each provide the information about the failed system functions with the associated criticality.

In block 86 , suspect components may be determined based on a given faulty function. For this purpose, starting from the faulty function, that is to say the element of the function hierarchy 14 with the state inactive, all subordinate functional states are determined on the basis of the table of the output-input relations given above. The error states of the lowest level elements of the function hierarchy 14 , for example the elements 44 to 52 , can be mapped to the lowest level elements of the component hierarchy 12 , namely the elements 22 to 30 , thus their states being known. By then going through the component hierarchy 12 in the direction of the arrows shown in FIG. 2, the component states can be determined by means of the above-indicated table of input-output relations, so that the output from block 86 is a list of suspect components stands.

Based on the input of faulty components, which means elements of the component hierarchy 12 with the state inactive, a smallest exchangeable unit can be determined in block 88 . This may be done after mapping the states of the elements of the lowest level function hierarchy 14 , such as elements 44 through 52 , to the lowest level elements 22 through 30 of the component hierarchy 12 , by moving the component hierarchy 12 in the direction of that shown in FIG. 2 arrows is traversed until the search process encounters an element having the attribute smallest exchangeable unit as well as the state inactive. The states of the respective higher-level elements of the component hierarchy 12 result from the previously indicated table of input-output relations.

As can be seen from the illustration of FIG. 1, at each step of the search methods explained with reference to blocks 84 , 86 and 88 , respectively, the function and component hierarchy 10 , the configuration table 80 and the dynamic inference data 82 are accessed.

Claims (5)

A diagnostic module, in particular for the on-board diagnosis of a mechatronic vehicle system, comprising a system diagnostic model ( 10 ) which maps components of the system into a component hierarchy ( 12 ) and the functions of the system into a functional hierarchy ( 14 ), elements ( 16 , 18 , 20 , 22 , 24 , 26 , 28 , 30 ) of the component hierarchy ( 12 ) by means of conjunctions and elements ( 32 , 34 , 36 , 38 , 40 , 42 , 58 , 60 , 44 , 46 , 48 , 50 , 52 , 68 , 70 , 72 ) of the functional hierarchy ( 14 ) are linked by conjunctions ( 54 , 56 ), disjunctions ( 62 ) and / or negations, characterized in that for linking the elements of the functional hierarchy ( 14 ) also antivalencies ( 64 ), Equivalents ( 66 ) and / or more-than-n functions ( 74 ) are used. 2. Diagnostic module according to claim 1, characterized in that a configuration table ( 80 ) is provided by means of the individual elements of the functional and component hierarchy can be selectively activated or deactivated. The diagnostic module according to claim 1 or 2, characterized in that memory space ( 82 ) is provided for dynamic inference data arising during performing a system diagnosis as variable data, and means ( 84 , 86 , 88 ) for taking into account the dynamic inference data during of performing a system diagnostics are provided. 4. System diagnostic method, in particular for the on-board diagnosis of a mechatronic vehicle system, by means of a diagnostic module according to one of the preceding claims, characterized by the consideration of a set by means of a configuration table ( 80 ) activated or deactivated state of elements of the functional and component hierarchy ( 12 , 14 ) when performing the system diagnostics. 5. System diagnostic method according to claim 4, characterized by storing dynamic inference data that while performing a system diagnostics as changing data emerge, and by taking into account the dynamic inference data when performing the System diagnostics.