DE10361072A1 - Diagnosis for control units in mechatronic systems, whereby the signal states of interacting components assigned to different functional units affect the loading or unloading of components in another functional unit - Google Patents

Abstract

Diagnosis of at least a control unit of a mechatronic system that comprises at least two functional units, whereby the first functional unit has at least two components that are assigned to at least a control unit and at least a signal of the first functional unit and at least a signal of the second functional unit are assigned a state. The second functional unit has at least one component that is the same as a component of the first functional unit and at least one that is different. The signal states ok and nok, i.e. not ok, are recognized and the signal state of the components of the second functional unit load or unload the first functional unit. An independent claim is made for a device for diagnosis of at least a control unit of a mechatronic system.

Description

The The invention relates to a method and a device for Diagnosis of at least one control unit in a mechatronic System. Mechatronic systems are, for example, production machines, Robots, aircraft, rail vehicles or motor vehicles.

a control unit are various components, such as sensors, actuators, switches, Plug, ground points and / or cables assigned. It is conceivable the control unit form such that it is only a forwarding and / or a reception of data between components assigned to it and with him networked control units and / or serves these assigned components. Preferably, however, the controller is formed with a computing unit, by which, for example actuators associated with it can be controlled and / or regulated and / or Sensor data is collected and processed. The control units are over one Bus system, such as a CAN bus, and / or other data lines networked.

In safety-critical mechatronic systems, for example in In a motor vehicle drive system, it is necessary to make mistakes quickly and reliable to recognize. It is therefore known controllers a diagnostic module for a self-diagnosis assigned. The self-diagnosis detects an implausible behavior of the controller and the associated peripheral and stores an interpretation of this Behavior as an error code. The error is for example in one Workshop can be called up and analyzed with the help of a workshop tester.

is a control unit not self-sufficient in a mechatronic system but with at least one another control unit networked and / or are different components of a controller from each other dependent, such is an interpretation of the self-diagnosis detected on a control unit Error behavior is often not clear. So can an error of a component of the mechatronic system cause several error messages (Error report), without the actual causer recognizable becomes.

From the DE 100 51 781 A1 is a diagnosis in two stages, namely a component diagnosis and a central system diagnosis, known, wherein the component diagnostics, a system size and the system size associated condition is determined and fed to the central system diagnostics. A distinction is made between possible states of the components as "normal", "faulty" or "unknown." In the central system diagnosis, the results of the component diagnosis are linked with at least one functional state of a function of the components (hardware function) taking into account model data of the system On the basis of the function determined, an associated faulty component as well as a smallest replaceable unit can be determined again, but a disadvantage of the method is the high computational effort and the additional loading of the bus system.

Of the The invention is therefore based on the technical problem, an improved To provide a method and a simplified device for the diagnosis of ECUs.

The solution of the problem results from the objects with the features of claims 1 and 11. Further advantageous embodiments of the invention will become apparent from the dependent claims.

For this purpose, a signal of a first functional unit, which comprises at least two components of at least one control unit, and at least one signal of a second functional unit, which coincides in at least one component with the first functional unit and differs in at least one component from the first functional unit, assigned states, where "normal"("ok") and "not normal"("nok") are distinguished as states. Due to the state of the signal of the second functional unit, components of the first functional unit are loaded or unloaded. Components are, for example, sensors, actuators, lines, switches, plugs, and / or ground points. If erroneous and error-free signals depend on the same component, this component is usually not the cause of the error. The component is "relieved." If, on the other hand, all erroneous signals depend on a component, then this component can be the cause.The component is "loaded". The intersection of the components in the available functional units determines which number of suspect components an error localization can be limited to. A compromise between additional costs due to additional elements for the detection of functional states and a clear fault localization is to be found. In the simplest case, a diagnosis of a functional unit comprising two components is performed by a functional unit which comprises only one of the two components. However, it may be provided that at least individual components are charged only, but not relieved. Whether a burden-relief strategy or a pure stress strategy is performed, for example, can be determined depending on the nature of the component. For example, with a splice, a discharge may be wrong Conclusions lead. If, for example, three lines leave the splice, with two being defective or being torn off, the functional states of the functional units of the two defective lines would burden the splice and the third faultless line would relieve the splice. For such components, it therefore makes sense that only a load takes place here.

In a further preferred embodiment is the device for diagnosing the control devices in the mechatronic system implemented. This can be done, for example, by integration into the to be diagnosed control unit itself or in integration into a central control unit.

In an alternative embodiment the device is at least partially passed through an external diagnostic tester formed over at least one interface connectable to the mechatronic system is. Various embodiments are conceivable. So can For example, be provided that the signals of the functional units on the Transfer interface and then the further diagnosis including the Assignment of states takes place in the diagnostic tester. Alternatively, the assignment of the conditions on-board in the mechatronic system, in which case the assigned conditions transferred to the diagnostic tester and continue to be evaluated. Furthermore, it is also possible only To transmit errors and error codes to the diagnostic tester and evaluate what later even closer explained becomes. The system can therefore be described as pure on-board, off-board or Hybrid diagnostic system be formed. However, it should be noted that in off-board or hybrid systems the evaluation strategy opposite an on-board diagnosis may need to be adjusted because certain switching states of Actuators, for example, are not available.

Next a diagnosis during during normal operation or for repair or maintenance purposes can the device and the method also used to monitor a production process become. For this example, after the assembly, the diagnostic module started so early For example, plug errors are detected.

The Interface can be used as an electrical connector and / or be designed as an RF or infrared air interface. Preferably In doing so, recourse is made to existing interfaces, for example the K-line with a CAN bus. However, it is possible useful for data transmission reasons, direct high-speed interfaces at the control unit and / or bus.

In a further preferred embodiment Function units become temporary educated. As a result, special signals can be generated in the event of a fault, which can be used to diagnose a control unit. The number At formed functional units is arbitrary. The more functional units formed The better the number of suspicious components can be reduced. But this also increases the time required and / or possibly an additional Wiring. In addition, it is conceivable that the evaluated Signals are generated during normal driving.

In a preferred embodiment be in a dependency matrix physical dependencies between signals of the functional units and the components. In the dependency matrix are dependencies clear and easy to display.

Especially in the automotive industry there is a large variety of variants. Therefore Preferably, a kind of master dependency matrix is formed in which all possible built-in components with the possible hardware features or functional units are shown. To make a meaningful To be able to carry out diagnostics, especially in production, is first checked for what for a variant it is about. All functional units or hardware functions, which contain a certain component, not in the variant is therefore disabled or deleted. Then you can then the diagnosis with the remainder matched to the variant Function units performed become.

In a preferred embodiment a functional unit is assigned an element, wherein a signal the functional unit prepared by the element for the control unit becomes. As elements are, for example, driver units, decoders etc. conceivable, which process signals of the functional unit for the control unit. It is also conceivable that functional units by internal and / or external sensors are observed. As external sensors are, for example Temperature sensors and / or sensors for detecting positions conceivable, monitored by which individual components and / or a functional unit become. External sensors are as close as possible to the monitored Component and / or disposed at another suitable location. Internal sensors are sensors arranged in the control unit are and / or form a unit with this. As an internal sensor is for example a surveillance the power requirement of a functional unit conceivable.

Preferably, a state is considered "ok" if the signal is within a specified range defined upper and lower limits of the signals of the associated functional unit. This allows a quick and easy check of the condition. The areas are not rigid and may vary depending on the application and / or time. In addition, several areas may exist. The check can be made for example by suitable decoder, the decoder can be formed such that they also prepare the signals for the controller.

In a preferred embodiment the functional units are assigned to a control unit. This is one Diagnose the components on this controller without transferring data to others ECUs possible. In addition, it is also conceivable that components and / or functional units different control devices assigned.

In a preferred embodiment be signals of a functional unit with state "nok", which via a Distributed data bus or other comparable data line, indicated by an error code or an error signal. States received Signals are based on the error code or error signal a networked control unit and / or another functional unit recognizable. That's it avoidable, that erroneous signals in networked control units processed further and thereby generate new errors.

In a further embodiment Function units are dependent the state associated with error codes or error signals, wherein the Number of distinguishable error codes or error signals optimized becomes.

are two functional units identical error signals or error codes is assigned because of this error signal or error codes only detectable that one and / or more components off one or both functional units work incorrectly. A closer one Limitation is not possible with identical error signals or codes. Become However, the functional units different error codes or Assigned error signals, so can the number of suspects Components restricted become. Be for both functional units receive error codes or error signals, so components are loaded, which in both functional units available. With only one faulty functional unit these components are relieved, however. With the number of to disposal standing functional units is an optimal, i. minimum, number at distinguishable error codes or error signals at a given Number of identifiable polluters determinable and / or at one predetermined number of error codes or error signals are these assignable to certain functional units, so that a maximum Number of possible Causing is identifiable. Optimizing the number of Error codes or error signals and / or their assignment to certain Functional units preferably takes place in the initial and / or further development of the mechatronic Systems or parts thereof. It can on the already mentioned dependency matrix resorted become.

The Error signals or error codes of a control unit can be forwarded and, for example be evaluated at a central location and / or in another control unit be linked with the error signals or error codes. As central evaluation point For example, a special computing unit and / or a diagnostic device are conceivable. The arithmetic unit and / or the diagnostic device are designed such that they recognize error signals or error codes and the one or the other corresponding functional units) can assign. Preferably takes place the training such that due to a label, for example an associated transmission period and / or addressing between Error signals of different functional units are distinguished can.

In a further preferred embodiment a distinction is made between static and sporadic errors. This sporadic error is understood as an error that only temporary occurs. Cause can be, for example, a loose contact. to Recognition of such errors must therefore take into account the history where a component loaded by sporadic errors is not by static conditions may or should be relieved. Under static errors are Understand mistakes that are permanent. In the evaluation Note how the error signals are generated. For example a component divided into three functional units, with at two functional units sporadic errors are taken into account in the third functional unit, however, only static errors, so comes in case of a sporadic error the component causes the two first functional units recognize the sporadic error and the Load component. The third functional unit, however, recognizes while temporary However, this error entry is deleted if necessary due to the loose contact the error disappears again. In that moment would be the third functional unit relieve the component again. thats why Depending on the component suitable to determine whether purely static and / or sporadic fault diagnostics are performed or whether mixed Considerations of static and sporadic errors are performed. It is important to ensure that in case of doubt, no faulty components be relieved.

In a further preferred embodiment At least the state of the first functional unit is checked periodically. The periodic review takes place preferably only with active functional units, i. with functional units with actuators only if the actuators are active. It is beside it also conceivable that the plausible range of inactive functional units is determined accordingly.

In a further preferred embodiment distributed a control unit at least one signal is cyclically connected to networked during error-free operation ECUs. If an error is detected in a functional unit of the control unit, so at least the associated Signal not distributed to networked control units. It is beside it also possible that the associated control unit after the occurrence of an error for all its associated functional units sends no more signals. The two states "ok" and "nok" are thereby clear identifiable without further signals via the data bus and / or a other data line to be sent. The data bus and / or the data line are therefore not burdened by the diagnosis. Because signals of others ECUs and / or functional units continue to receive is a Absence of signals due to faults in functional units distinguishable from a data bus error. Other safe methods However, differentiation is conceivable.

The Invention will be described below with reference to a preferred embodiment explained in more detail. The Figures show:

1 a schematic representation of a control device with five associated components and

2 a schematic representation of a dependency matrix.

1 schematically shows a control unit 1 comprising a central processing unit 10 , Component diagnoses 11 , a store 12 , an interface 13 and elements 14 . 15 . 16 as an interface for hardware functions. The control unit 1 There are five components assigned to K1-K5. In this case, a first hardware function depends on the components K1, K2 and K5 and is the element 14 assigned. A second hardware function depends on the components K1-K4 and is the element 15 assigned. A third hardware function depends on the components K1, K4 and the element 16 assigned. Components include sensors, actuators, switches, connectors, grounding points and / or cables.

The Elements 14 - 16 For example, they are designed as hardware drivers by which signals of the hardware functions can be interpreted. The signals become component diagnoses 11 supplied and checked by them for plausibility. A signal is considered plausible if it is within a certain range. Plausible states are marked with "ok", non-plausible states with "nok". The signals of the functional units are dependent on at least two components. The causative component of an applied "nok" state is therefore through the component diagnostics 11 not clearly determinable. The results of component diagnostics 11 are therefore in the central processing unit 10 evaluated. It is conceivable, the component diagnoses 11 together and / or as part of the central processing unit 10 train. Preferably, the elements 14 - 16 together with the component diagnoses 11 educated. For example, a common training as a decoder is conceivable, by which the signals are received, interpreted and checked for plausibility.

Since only two states "nok" and "ok" are to be distinguished, a simple marking is possible. By way of example, it is sufficient as a marking that signals with "nok" states are not sent to the central processing unit 10 be transmitted. In error-free operation, component diagnostics 11 , which are assigned to an active hardware function, cyclic signals to the arithmetic unit 10 transfer. The absence of the signal thus signals the "nok" state 10 is to be designed in such a way that it can distinguish a failure of non-activated functions from a lack of signals due to an error.

In the central processing unit 10 Evaluation of component diagnostic results is based on dependency matrices. The dependency matrices are in the memory 12 stored.

Error signals or error codes of component diagnostics 11 may also be due to errors in component diagnostics 11 and / or the elements 14 - 16 be generated. This case is neglected in the following analysis for a better overview.

2 shows a dependency matrix for the controller 1 with the associated components K1-K5 according to 1 , In the dependency matrix, the components K1-K5 are plotted in a direction k and the hardware functions H1-H3 in a second direction h. In the illustrated example, the hardware function H1 is dependent on the components K1, K2, K5, the hardware function H2 of the components K1-K4 and the hardware function H3 of the component K1, K4. If at least one error occurs in a hardware function, so he follows an evaluation by loading and unloading of individual components. All available hardware functions with "ok" or "nok" status are considered for the evaluation. Inactive functions do not allow conclusions and are therefore not considered. However, it is conceivable to activate individual non-active functions and to use the results for the evaluation. A component will be charged if all hardware functions are "nok" -dependent, and a component will be relieved if at least one "ok" hardware function depends on it.

has For example, the hardware function H2 is not plausible and / or faulty behavior, i. a "nok" state, so can one or more components K1-K4 cause. Now have the hardware function H1 and H3 on both error-free states ("Ok" conditions), so will the components K1, K2, K4 relieved. Accordingly, the components K3 as causal for the faulty behavior detected. On the other hand, assign all functions faulty behavior, so is probably the component K1 causal.

For the evaluation in the arithmetic unit 10 All available signals are considered with "ok" or "nok" status. Inactive hardware functions do not allow conclusions and are therefore not considered. However, it is conceivable to activate individual non-active functions and to use the results for the evaluation. In addition, it is also conceivable to form functional units by selectively deactivating or activating components

The components K1-K5 can be as in 1 represented a control unit 1 be assigned. However, it is also conceivable that components K1-K5 are assigned to different networked control devices. The evaluation is conceivable both in a central processing unit and in individual control units.

The control unit 1 is via a data bus 4 Networked with other control devices and / or connected to a diagnostic device. For communication with networked control devices is the control unit 1 with the interface 13 educated. the interface 13 and / or the central processing unit 10 check received signals. If the received signals have an error code, for example a "nok" state, then these are in the control unit 1 not used. Instead, the controller performs 1 a runflat strategy or ignore the signals if possible. Accordingly, erroneous states of the signals will be forwarded by the controller 1 characterized.

It is conceivable that the control unit 1 in error-free operation periodically signals via the data bus 4 sends. If an error occurs on a component K1-K5 and / or a hardware function H1-H3, the associated signals are no longer transmitted. The absence of signals signals for networked ECUs that an error has occurred.

Claims (22)

Method for diagnosing at least one control unit of a mechatronic system, comprising at least two functional units, wherein the first functional unit comprises at least two components which are assigned to at least one control unit and states are assigned to a signal of the first functional unit and at least one signal of the second functional unit, characterized the second functional unit in at least one component (K1-K5) agrees with the first functional unit and differs from the first functional unit in at least one component (K1-K5), as states "normal"("ok") and "not normal"("Nok") and the state of the signal of the second functional unit components (K1-K5) of the first functional unit loaded or unloaded. Method according to claim 1, characterized in that that functional units are temporary be formed. Method according to claim 1 or 2, characterized that physical dependencies between Signals of the functional units and the components (K1-K5) in one Dependency matrix shown become. Method according to one of claims 1 to 3, characterized in that the signal is transmitted through an element ( 14 - 16 ) is prepared for the control unit. Method according to claim 4, characterized in that that an operating condition is classified as "ok", if the signal is within a specified range. Method according to one of the preceding claims, characterized in that the functional units a control unit ( 1 ) assigned. Method according to one of the preceding claims, characterized characterized in that at least the signals of a functional unit with state "nok" markable are distributed to at least one networked controller. A method according to claim 7, characterized gekenn illustrates that functional units are assigned error codes or error signals depending on the condition, optimizing the number of distinguishable error codes. Method according to one of the preceding claims, characterized characterized in that the state is checked periodically. Method according to one of the preceding claims, characterized in that a control device ( 1 ) at least one signal with state "ok" cyclically distributed to networked ECUs and a signal with state "nok" does not send. Device for diagnosing at least one control unit of a mechatronic system comprising at least two functional units, wherein the first functional unit comprises at least two components, which is assigned to at least one control unit are and a signal of the first functional unit and at least a signal of the second functional unit states can be assigned, characterized in that that the second functional unit in at least one component (K1-K5) coincides with the first functional unit and in at least a component (K1-K5) is different from the first functional unit, as states "normal" ("ok") and "not normal "(" nok ") are distinguishable and the state of the signal of the second functional unit components (K1-K5) of the first functional unit loaded or unloaded. Device according to claim 11, characterized in that that the device is arranged in the mechatronic system. Device according to claim 11, characterized in that that the device comprises an external diagnostic tester, the by means of at least one interface with the mechatronic system is connectable. Device according to one of claims 11-13, characterized that functional units are temporary are imageable. Device according to one of claims 11 to 14, characterized in that physical dependencies between signals of the functional units and the components (K1-K5) can be represented in a dependency matrix and the dependency matrix in a memory ( 12 ) can be stored. Device according to one of claims 11 to 15, characterized in that a functional unit assigned an element, wherein a signal of the functional unit by the element ( 14 - 16 ) is editable for the control unit. Device according to one of claims 11-16, characterized in that an operating state is classified as "ok" when the signal of the element ( 14 - 16 ) is within a specified range. Device according to one of claims 11 to 17, characterized in that the functional units a control device ( 1 ) are assignable. Device according to one of claims 11 to 18, characterized that at least the signals of a functional unit with state "nok" identifiable are distributed to at least one networked controller. Device according to one of claims 11-19, characterized that functional units depending on the state error codes or error signals can be assigned, wherein the number of distinguishable error codes can be optimized. Device according to one of claims 11 to 20, characterized that the condition is periodically verifiable. Device according to one of claims 11 to 21, characterized in that by a control device ( 1 ) at least one signal with state "ok" can be cyclically distributed to networked control devices and a signal with state "nok" is not sent.