Test bench for confronting test object with electric failures to be simulated
The test bench design addresses scalability and integration challenges by using local nodes to autonomously manage simulated electrical errors, improving the test bench's flexibility and ease of integration with custom FIUs.
Patent Information
- Application Number
- JP2024198852
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2024-07-09
- Filing Date
- 2024-11-14
- Publication Date
- 2025-05-26
AI Technical Summary
Existing Hardware-in-the-Loop test benches for simulating electrical errors in control systems face scalability issues and difficulties in integrating non-standard Failure Insertion Units (FIUs) due to complex error management and dependency on central error control unit design.
A test bench design that includes a central error control unit and local nodes (FIUs) capable of autonomously deriving drive control rules for switch devices to simulate electrical errors, allowing for improved scalability and easier integration of custom or third-party FIUs.
The solution enhances the scalability of the test bench by enabling local FIUs to manage simulated errors independently, simplifies the integration of new or custom FIUs, and reduces the adaptation required for the central error control unit.
Smart Images
Figure 2025080780000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the simulation of electrical errors in a control system.
Background Art
[0002] Control systems for driving and controlling mechatronics systems of electronic control units (ECUs), which are often assembled in a compact and enclosed form, are checked for correct functionality before their production begins. In particular, for safety-critical control systems where malfunctions can have serious consequences in the field, it is common practice to verify the validity of the control system on a test bench for this purpose. This test bench provides a virtual working environment that is close to reality for the control system. In this working environment, the control system can be confronted with various situations as expected and reproducibly in order to test its response to these situations. Such a test bench is known in the industry as a Hardware-in-the-Loop test bench (abbreviated as HIL).
[0003] The tests to be performed may include checking the response of the control system to electrical errors in the working environment of the control system. Electrical errors can basically be understood as any deviation of the current in the working environment from a pre-set guide for this current flow. Examples are interruptions due to cable breaks, short circuits or leakage currents due to cable wear. In the market, test benches configured for the simulation of electrical errors are available for this purpose. Such test benches generally include special electrical lines for conducting or transmitting the simulated incorrect current and switches for forming or disconnecting electrical connections to the above-mentioned lines.
[0004] In the prior art, these switches are generally arranged in modular error simulation units (FIU: Failure Insertion Units) and are distributed across the test bench, but are driven and controlled by an error control unit at the center of the test bench. Such a design is disadvantageous in two respects. On the one hand, each FIU added to the test bench increases the complexity of error management executed by the error control unit. That is, the test bench has poor scalability. On the other hand, in order to correctly drive and control the switches incorporated therein, the error control unit must know the design of the FIU. This makes it difficult, for example, to integrate special FIUs different from the standard design that meet special customer requirements and / or are supplied by third parties.
Summary of the Invention
Problems to be Solved by the Invention
[0005] Against such a background, an object of the present invention is to facilitate the drive control of local error simulation units by a central error control unit.
Means for Solving the Problems
[0006] The present invention for solving this problem is a test bench for confronting a specimen, particularly a control system, with a simulated electrical error. The test bench includes a central error control unit for collecting the simulated electrical errors, and at least one first local node for executing an error simulation triggered by the error control unit. The local node is an FIU, and the execution of the error simulation is performed by driving and controlling the initial arrangement of the switches so as to tamper with the selected current in the test bench.
[0007] The error control unit is configured to create a first abstract error description that specifies at least one first electrical error for connection to a first electrical line and transmit it to a first local node. The first local node derives, from the first abstract error description, a first drive control rule for a first switch device suitable for connecting the first electrical error to the first electrical line, and drives and controls the first switch device according to the first drive control rule, thereby being configured to connect the first electrical error to the first electrical line.
[0008] The abstract error description should be understood as a set value for an electrical error. This set value pre-sets a specific electrical error connected to a specific electrical line, but does not name a specific switch of the first switch device or another switch device that is driven and controlled by the local node to connect the error, nor does it include a set value regarding how these switches are driven and controlled. Therefore, according to the present invention, the local FIU only includes a basic description of the electrical error connected to one or more electrical lines, and is configured to autonomously derive the drive control of the switch that realizes the electrical error according to the description from this basic description.
[0009] In this way, according to the present invention, the scalability of the test bench is improved by enabling the FIU to automatically manage the connection of the simulated error. Further, according to the present invention, the development of a new FIU is facilitated, especially as an individual component or a custom-made product. The newly developed FIU only needs to understand a pre-set protocol used by the central error control unit. The necessary adaptation to the central error control unit for driving and controlling the newly developed FIU is significantly reduced or, in an advantageous embodiment of the present invention, is no longer required at all.
[0010] Basically known in the prior art is to outsource the intelligence for driving and controlling a switch from a central control instance to a local node. For example, U.S. Patent Application Publication No. 20230333585 describes a home power grid with a distributed local switch unit that can connect or disconnect an electrical consumption device based on locally stored control software or from a solar power generation facility. The driving and control of the switch are based on the evaluation of the power converted by the load and the prioritization of the load, and the switching operation is limited to simply connecting or disconnecting the electrical connection from the load to the energy source. Deriving complex switching operations for flexibly realizing various current flows independently is not specified in the teachings of the above patent application.
[0011] The first local node is preferably configured as a modular component that can be easily removed from the test bench without being damaged, particularly as a pluggable printed circuit board.
[0012] The central error control unit is preferably configured to read a wiring description stored in the storage medium of the test bench in order to summarize electrical errors. This wiring description includes a list of the electrical lines of the test bench, including the first electrical line, and also stores, in particular, other information necessary for summarizing electrical errors.
[0013] The error control unit is advantageously configured to specify a first electrical error in a first abstract error description as a cable break, short circuit, leakage current to ground, creep current between a first electrical line and a second electrical line, poor contact or bounce pattern (e.g., a vibrating cable end or an undesired electrical contact connection having a time-varying resistance as a result of vibration). The specification of the electrical error should in this case be understood as a certain number of basic characteristics of a specific error type, which are transmitted by the error control unit to a first local node in the first abstract error description. For example, "leakage current to ground" can be specified by a part of the current intensity conducted through the first electrical line branching off from the first electrical line and being conducted to a special guide rail provided to discharge the simulated leakage current. After receiving this specification by the first local node or the FIU according to the invention, a switch configuration is derived autonomously, from which a connection conducted through an electrical resistance is formed from the first electrical line to the special guide rail. Of course, the basic characteristics can be supplemented by specific setting values in the first error description. The specific setting values can be, for example, the current intensity or the electrical resistance of the leakage current. The first local node or the FIU according to the invention can utilize this setting value, whereby a simulated leakage current is conducted through a controllable resistance and the controllable resistance is set such that the current intensity or the electrical resistance of the simulated leakage current conforms to this setting value.
[0014] The first electrical line can basically be configured as an energy line, or as a data line, or as a combination of two lines (PoC: Power over Coax, PoE: Power over Ethernet, etc.), and preferably, it is provided at a direct electrical connection part with the subject, whereby the connection of the first electrical error to the first electrical line directly acts on the subject. In other words, the first electrical line is advantageously configured to conduct a current that transfers energy and / or information from the subject to the test bench or transfers energy and / or information in the reverse direction from the test bench to the subject.
[0015] The test bench advantageously includes an error guide rail device, that is, an electrical line specifically laid on the test bench to transmit current and simulate electrical errors. The first local node is configured to form an electrical contact connection of the first electrical line to the error guide rail by driving and controlling the first switch device. The error guide rail device particularly preferably includes error guide rails extending in parallel, whose electrical characteristics are different and are optimized for simulating various types of electrical errors. In particular, one error guide rail may be optimized to conduct a high current intensity, and one error guide rail may be optimized to conduct an electrical signal for information transmission, that is, optimized as a data line.
[0016] In the extended stage of the present invention, the first local node is configured to inspect a first error description for executability and return a message of confirmed non - executability of the first error description. This returned message may be sent to a central error control unit or another instance of the test bench, for example, to the graphical user interface (GUI) of the operating components of the test bench. Here, the inspection for executability includes an inspection of whether the technical components of the first local node, particularly the switches of the first switching device, meet the specifications required to connect a first electrical error according to the first error description. This inspection may include a comparison between the time setting value in the first error description and the switching time of at least one switch of the first switching device to check whether the time setting value can be met. This inspection may include a comparison, particularly to avoid damage to the components of the first local node, between the current tolerance of at least one switch of the first switching device and the current tolerance setting value included in the first error description. This inspection may particularly include a comparison between the breakdown voltage of at least one switch of the first switching device and the voltage setting value included in the first error description. This inspection may include an inspection of the compatibility between the first drive control rule and another drive control rule already stored in the first local node. In particular, the first electrical error and the electrical error connected by another drive control rule are not compatible if, for example, they cannot be executed simultaneously due to the switch being used doubly.
[0017] The test bench's FIU preferably includes both mechanical switches and semiconductor switches. Mechanical switches generally have a higher current tolerance and better insulation in the open state. Mechanical switches are thus particularly suitable for transmitting high current intensities or simulating cable breaks at high voltages. Semiconductor switches are controllable and have a shorter switching time. Thereby, semiconductor switches are particularly suitable for simulating leakage current, bounce patterns, and high-speed switching operations. Particularly preferably, each FIU includes both semiconductor switches and mechanical switches so that a number of different types of electrical errors can be locally simulated respectively, similar to the first local node.
[0018] The first local node preferably transmits to the error control unit a request for a first period required to connect the first electrical error, so that the error control unit can take the first period into account when summarizing the simulated electrical errors. The first period can be determined in particular based on the switching times of the switches handled in the first drive control rule.
[0019] Particularly advantageously, the error control unit is configured to use the first period to synchronize the connection of the first electrical error and the connection of at least one second electrical error by the second local node. Here, the first electrical error and the second electrical error may be purely temporally correlated and may not depend on each other in other respects. However, it is also possible to synchronize the first electrical error and the second electrical error for the purpose of connecting an electrical macro error. For this connection, the first local node, the second local node, and possibly even another local node may be required. Exemplarily, the electrical macro error may be a leakage current from the first electrical line to the second electrical line. What is required for the simulation of this leakage current is to connect the first electrical line to the error guide rail by the first local node and connect the same error guide rail to the second electrical line by the second electrical node.
[0020] In this feature of the present invention, the error control unit is configured to create a second abstract error description specifying at least one second electrical line and a second electrical error connected to the second electrical line and transmit it to the second local node. The second local node includes a second switching device, and the second local node derives, from the second abstract error description, a second drive control rule for the second switching device suitable for connecting the second electrical error to the second electrical line, determines a second period required for connecting the second electrical error, transmits the second period to the error control unit, and drives and controls the second switching device according to the second drive control rule, so as to be configured to connect the second electrical error to the second electrical line. The error control unit is configured to synchronize the connection of the first electrical error and the connection of the second electrical error in consideration of the first period and the second period.
[0021] According to an embodiment of the present invention, the second abstract error description may be different from the first abstract error description, or may be the same as the first abstract error description. In one possible embodiment of the present invention, an individual error description is created for each local node by an error control unit. However, in this embodiment, a part of the error plan remains in the error control unit, and it must be derived by this error control unit how each local node is involved in the connection of a given error. Advantageously, the error plan is completely outsourced to local nodes.
[0022] For this purpose, the error control unit is configured to send, in the form of a broadcast, an error description for describing an error to all local nodes incorporated in the test bench, and moreover, regardless of whether only one local node is involved in this error or whether it is a macro error in which two or more local nodes are involved in its connection. Therefore, in this embodiment, the first local node, the second local node, and another local node incorporated in the test bench receive a copy of the same error description. Each local node, particularly the first local node and the second local node, is configured to analyze the error description, identify based on this analysis whether the error description itself is involved in the connection of the error, and further ignore the error description if not involved.
[0023] For the connection of macro errors, of course, according to this embodiment, a predetermined agreement is required between local nodes involved in the connection of the macro error. For example, to take up again the just-described example of the leakage current between the first electric line and the second electric line, when specifying the resistance of the leakage current in the error description concerned, what must be determined by the rules is how each of the first local node and the second local node contributes to the connection of the resistance.
[0024] Various solutions can be considered for this. For example, in such a case, two local nodes can be configured to connect half of the resistors specified respectively. Alternatively, based on a predefined hierarchy of local nodes, it can be determined which local node is responsible for connecting the resistors. Here too, alternatively, the first local node and the second local node can be configured to exchange messages with each other in order to determine whether the first local node and the second local node are responsible for connecting the resistors. Another possibility is to avoid such ambiguous task assignments from the beginning by a unique system architecture. What this can mean in the above example is, for example, that only the first local node of the local nodes is configured to connect a resistor to the error guide rail in the first place, and the second local node is configured to ignore the corresponding specification of the resistor, or a third local node dedicated for this purpose is arranged on the error guide rail in order to control the electrical resistance of the error guide rail.
[0025] The following description of the drawings outlines the embodiments of the present invention.
Brief Description of the Drawings
[0026]
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
DETAILED DESCRIPTION OF THE INVENTION
[0027] FIG. 1 exemplarily shows a test bench 2 connected to a subject via two electrical lines 6, namely a first electrical line 6a and a second electrical line 6b. The first electrical line 6a and the second electrical line 6b represent electrical lines through which the subject 4 can be incorporated into the working environment in normal operation to exchange electrical energy and / or data with the working environment. The test bench 2 is configured to drive and control the current flow in the electrical line 6, thereby simulating a reliable and realistic normal operation in the working environment for the subject 4. For this purpose, the test bench 2 includes a central processor, which is also configured as a central error control unit 10, and further processes a simulation model, generates integrated sensor data based on the simulation model, supplies it to the subject 4, reads control data from the subject 4, takes it into account in the simulation model, and induces a current in the electrical line 6 or responds to the current induced by the subject in the electrical line 6. In this way, the test bench 2 provides a virtual working environment for the subject, within which the subject can safely and reproducibly inspect its correct functions. The subject 4 may in particular be an electronic control device for driving and controlling, for example, a motor, a battery, an inverter or any electrical equipment.
[0028] In its function as the central error control unit 10, the central processor is configured to connect electrical errors to the electrical line 6 using the local node 8 configured for this purpose in order to examine the desired reaction of the subject 4. For this purpose, the test stand 2 includes a first local node 8a and a second local node 8b. The two local nodes 8 are configured as modular, replaceable FIUs. The test bench 2 further includes an error guide rail device represented in the drawing by a first error guide rail 12 and a second error guide rail 14 extending parallel to the first error guide rail 12. The error guide rail device is arranged in a bus shape in the test bench 2, whereby, by connecting the error guide rails to each other and / or by the FIUs 8 arranged at different locations in the test bench 2, each FIU 8 of the test bench 2 can be connected to the error guide rail device, and in this way, a plurality of current paths for the simulation of electrical errors can be realized. The error guide rails extending in parallel may have different electrical characteristics. Exemplarily, the first error guide rail 12 is optimized for the conduction of high current intensity, and the second error guide rail 14 is optimized for the transmission of signals.
[0029] The first local node 8a includes a first switch device 16a, and the first switch device 16a can form an electrical contact connection between the first electrical line 6a and the first error guide rail 12 or the second error guide rail 14. The first switch device 16a further includes a switch for interrupting the first electrical line 6a and a switch for increasing the electrical resistance of the first electrical line 6a. The first switch device 16a includes a plurality of switches having different technical specifications and characteristic numbers. In particular, the first switch device includes a mechanical switch designed for a high current intensity line and a semiconductor switch that can be switched quickly and accurately in time and is controllable.
[0030] The illustration of the first switch device 16a is significantly simplified. Market-based FIUs include a complex network of switches that are much less obvious in the figure for driving control to connect electrical errors than those shown in the figure.
[0031] The first local node 8a includes a first local memory 20a and a first local processor unit 18a for driving and controlling individual switches in the first switch device 16a. The first local memory 20a stores, either by itself or as stored by the error control unit 10 as described below, all the information required by the first local processor unit 18a to drive and control the first switch device 16a according to the present invention. The information stored by itself includes at least a list of switches in the first switch device 16a and a list of characteristic quantities of the individually listed switches. Possible examples of characteristic quantities are the limit of the transmissible current intensity, the switching time, the control quality (e.g., rise time, overshoot width, fall time), the control accuracy, and the breakdown voltage. The first local processor unit 18a is configured to read and use the information stored in the first local memory 20a.
[0032] The second local node 8b is configured in the same way as the first local node 8a in its basic function and is similarly arranged to connect electrical errors to the second electrical line 6b. The second local node 8b includes a second switch device 16b, a second local processor unit 18b, and a second local memory 20b, which are configured similarly to their functional counterparts in the first local node 8a and are connected to each other. The second switch device 16b may differ in detail from the first switch device 16a, particularly in the number of switches, the technical specifications and characteristic numbers of the individual switches, and the circuit topology.
[0033] FIG. 2 schematically shows, in the form of a flowchart, an exemplary simulation execution performed by test bench 2 as seen from central error control unit 10. This simulation execution includes a simulation of electrical errors, which is aggregated by error control unit 10 in interaction with at least one local node 8. The local node described above may be the first local node 8a, the second local node 8b, or any other arbitrary local node (not shown). If more than one local node 8 is used by error control unit 10 during the aggregation of electrical errors, the flow shown in FIG. 2 is executed in parallel for each of the local nodes 8 used in the simulation execution.
[0034] In a first step 30, error control unit 10 loads a signal list and evaluates it. This signal list is a wiring description in which the first electrical line 6a, the second electrical line 6b, and a plurality of other electrical lines of test bench 2 are described. This signal list generally includes the electrical lines and components of test bench 2 that are specifically related to the simulation being executed, and this signal list describes their mutual electrical connections. The signal list further specifies the current or signal transmitted in the above-described electrical lines and the guidance through the electrical conductors within the framework of the simulation.
[0035] In the second step 32, the error control unit 10 extracts information related to the local node 8 from the signal list. This related information particularly includes the electrical line 6 and the error guide rails 12, 14, and the local node 8 may affect these current flows by means of the switching device 16. The related information further includes (optional or essential) information based on which the local node 8 can check the executability of the connected error, in particular the characteristic numbers of the error guide rails 12, 14, such as the maximum transmissible current intensity, and the current expected in the electrical line 6, such as the highest current intensity and the maximum voltage. That is, the information related to the first local node 8a will include, for example, the description of the first electrical line 6a, the first error guide rail 12, and the second error guide rail 14. The information extracted from the signal list for the local node 8 further includes all the information necessary for a defined error to be connected to the electrical line 6 by the local node 8. Subsequently, in the third step 34 by the error control unit 10, the extracted information is transmitted to the local node 8, and this extracted information is stored in its local memory 20 by the local node 8.
[0036] The first step 30, the second step 32, and the third step 34 are each part of the initial configuration phase of the test bench 2. After the end of this configuration phase, the error control unit 10 starts the simulation in the fourth step 36.
[0037] During the simulation execution, an error description can be stored in the memory readable by the central error control unit 10 using the operation component of the test bench 2. The operation component may be, for example, a terminal incorporated in the test bench 2, or a personal computer (PC) connected to the test bench 2 and installed with operation software. To store the error description, the user first creates an error scenario. This error scenario describes the electrical error to be simulated in relation to the virtual working environment of the subject 4, at a high level of abstraction and simulated by the test bench 2. The subject 4 may be, by way of example, a prime mover control device, and the test bench 2 provides a virtual prime mover vehicle drivable by the subject 4 as a virtual working environment for the subject 4. In this connection, the error scenario can describe the electrical error to be simulated, for example, as a cable break in a specific electrical line leading to a specific spark plug of the virtual vehicle, where the above-mentioned spark plug is incorporated into the simulation only as a virtual component without being attached to the test bench 2 as a physical component.
[0038] In addition to the description of the error, the error description also includes at least one trigger condition for connecting each error during the simulation. The trigger condition is determined by the user during the storage process of the error scenario. The trigger condition must be checkable by the central error control unit 10, but is basically arbitrarily configurable otherwise. The trigger condition may be, for example, an event simulated in the simulation, a flow of a predefined period, or an operation of a manual trigger by the operation component.
[0039] The central error control unit 10 automatically converts the error scenario into an abstract error description, and the new error description is stored in the memory provided therefor. The abstract error description is related to the specific physical electrical circuit 6 of the test bench 2 in addition to the error scenario. To convert the error scenario into an abstract error description, the central error control unit 10 accesses the signal list and the information from the virtual working environment. In the above example with the spark plug, for example, in the setup phase of the test bench 2, it may be determined that the electrical circuit leading to the spark plug is simulated by the first electrical circuit 6a. According to the requirement stored in the error scenario of simulating a cable break in the electrical circuit, in the error description derived therefrom, the physical interruption of the first electrical circuit 6a will be described.
[0040] During the simulation, in the fifth step 38, the central error control unit 10 checks whether there is a new error description, and the error description is regarded as a new error description if it has not been sent to at least one local node yet (seventh step 44). If this is the case, in the sixth step 42, the central error control unit 10 assigns a name to the new error description. This name is an arbitrarily configured identifier, and based on this identifier, the new error description can be uniquely identified in the further course of the simulation.
[0041] In the seventh step 44, the error control unit 10 creates a message containing the new error description and its name, and sends this message as a broadcast via the bus of the test bench 2, whereby a copy of the message is received by each local node 8. In this way, the error control unit 10 transmits the first error description in the form of a message to the first local node 8a and transmits the second error description identical to the first error description to the second local node 8b.
[0042] In parallel with the fifth step 38, the error control unit 10 checks, at the eighth step 40 during the simulation, whether the trigger condition for one of the existing (i.e., not new) error descriptions is satisfied. Immediately when the trigger condition for an error description is satisfied, the error control unit 10 reads out the name of the error description for which the trigger condition is satisfied, and at the ninth step 46, via the bus of the test bench, as a broadcast, transmits an execution instruction including the name of the error description to be executed to all local nodes, whereby this execution instruction is received by both the first local node 8a and the second local node 8b.
[0043] The flowchart of FIG. 3 schematically shows the steps executed by the local node 8 during the simulation. The test bench 2 is configured to store all the new error descriptions transmitted at step 42 in the local memory 20 of each local node 8 that receives the new error description. The local node 8 performs a periodic check at the tenth step 50 as to whether a new error description is stored in the local memory 20, where the error description is considered new if the process (eleventh step 52) for creating drive control rules for this error description has not yet been started.
[0044] If not started, the local node starts the routine stored in the local processor unit 18 to create drive control rules for its own switch device 16 in the 11th step 52. By this routine, the requirements stored in the error description are evaluated, and first, it is checked whether each local node 8 is involved in the connection of the electrical error described in the error description at all. If started, the error description is ignored by the local node 8, that is, the local node 8 sets the processing of the error description and deletes this error description from its own local memory 20. In the normal case, if the electrical line 8 of the test bench 2 to which each local node 8 is connected is included in the error description, the local node is involved in the connection of the error. For example, if an error description describing an error connected to the second electrical line 6b is found in the first local memory 20a by the first local node 8a, this error description will be ignored by the first local node. This is because the switch of the first device of the switch 16a is not connected to the second electrical line 6b.
[0045] If the local node 8 reaches the conclusion that it is involved in the connection of the error during the check, the local node 8 creates drive control rules for its own dedicated switch device 16 to connect the error specified in the error description to the electrical line 6 specified in the error description in consideration of the information stored in its own dedicated local memory 20.
[0046] In the 12th step 54, the local node 8 checks whether the error description is executable. In the 11th step 52, when it succeeds in deriving a drive control rule that satisfies the set value of the error description, the local node 8 evaluates that the error description is executable. If there is a drive control rule, in the 13th step 56, the local node 8 stores the drive control rule together with the name stored in the error description in the local memory 20. When, due to the routine stored in the local processor unit 18, it is evaluated that the set value of the error description cannot be satisfied and thus there is no drive control rule, in the 14th step 58, the local node 8 creates a message regarding the non - executability of the error description and sends this message to the central error control unit 10.
[0047] In parallel with the inspection of the new error description (10th step 50), in the 15th step 60, the local node 8 periodically checks whether there is a new execution instruction from the error control unit 10. If there is a new execution instruction, the local node 8 reads out the name stored in the new execution instruction, searches for the name in its own local memory 20, and if the drive control rule associated with the name is found in this local memory 20, the local node 8 executes the drive control rule associated with the name in order to connect the electrical error associated with the name to the electrical line 6. If the drive control rule associated with the name is not found by the local node 8, the local node 8 ignores this execution instruction.
[0048] Figures 4 to 6 show a test bench 2 with an exemplary modified switch configuration for connecting various electrical errors.
[0049] Example 1: Poor contact Figure 4 shows the switch configuration in the first example of the connected error. In this first example, in the fifth step 38, an error description describing a poor contact in the first electrical line 6a is found by the error control unit 10. According to this error description, the poor contact is specified as a bounce pattern of continuously changing lengths at random time intervals, in which there are alternating contact connections and no contact connections, and the average length is 5 seconds at intervals of 4.5 seconds.
[0050] In the sixth step 42, the error control unit 10 gives the new error description the name "Error 1" and sends this new error description to the local node 8 with this name.
[0051] What is confirmed in the twelfth step 54 during the evaluation of the new error description by the first local node 8a is that the first switching device 16a includes a controllable semiconductor switch (see the arrow), and this controllable semiconductor switch is suitable for connecting the error image "poor contact", and also through this semiconductor switch, this semiconductor switch can conduct the current conducted from the first electrical line 6a. The first local node 8a compares the specified current expected in the first electrical line 6a with the characteristic numbers of the identified semiconductor switch, and also confirms that the semiconductor switch can conduct the expected current intensity without damaging this semiconductor switch, and the voltage expected in the first electrical line 6a is lower than the breakdown voltage of the semiconductor switch.
[0052] In response, the first local node 8a creates a new drive control rule having an instruction for driving and controlling the first switch device 16a. These instructions are readable and interpretable by a drive control routine stored in the local processor unit 18a. The new drive control rule includes an instruction to open or switch all switches of the first switch device 16, except for the identified semiconductor switch, to a non-conductive state, an instruction to load the bounce pattern simulation routine stored in the first local memory 20a into the first local processor unit 18a, an instruction to configure according to the set value from the error description, and an instruction to alternately switch the semiconductor switch between a conductive state and a non-conductive state according to a preset bounce pattern by starting the bounce pattern simulation routine.
[0053] The first local node 8a evaluates the error description as being executable (step 54 of step 12), sends a corresponding confirmation signal to the central error control unit 10, and stores the drive control rule named "Error 1" in the first local memory 20.
[0054] In the next progress of the simulation, as soon as the trigger condition for "Error 1" is satisfied, the error control unit 10 sends an execution instruction "Execute Error 1" to the local node 8 (steps 40 of step 8 and step 46 of step 9). This execution instruction causes the first local node 8a to load the drive control rule named "Error 1" stored in the first local memory 20a and execute it by the drive control routine.
[0055] In the following example, only the differences from Example 1 will be described. A detailed description of the progress that proceeds in the same way as in Example 1 will be omitted.
[0056] Example 2: Leakage current to ground Figure 5 shows a switch configuration in a second embodiment of a connected error. In this example, what the error control unit 10 finds is an error scenario representing the discharge of a part of the current flowing to ground (e.g., the vehicle body) in the first electrical line 6a as a result of an undesired electrical contact connection (e.g., due to coating wear). The electrical resistance of the undesired electrical contact connection is specified as 5 Ω.
[0057] The error control unit 10 converts this scenario into an error description. With this error description, an electrical connection from the first electrical line 6a to the first error guide rail 12 is preset. This error description is named "Error 2" and is sent to the local node 8. The first local node 8a confirms that the first switching device 16a includes an appropriate controllable semiconductor switch, and with this semiconductor switch, the first electrical line 6a and the first error guide rail 12 can be connected with a desired resistance.
[0058] The first local node 8a creates a new drive control rule. This new drive control rule includes setting values such as adjusting the above-mentioned semiconductor switch to 5 Ω, conducting the main current of the first electrical line 6a without resistance through a closed mechanical switch, and opening or switching all the remaining switches of the first switching device 16a to a non-conducting state. The first local node 8a stores this new drive control rule in the first local memory 20a under the name "Error 2", and waits for an execution command "Execute Error 2" to execute the new drive control rule.
[0059] Example 3: Leakage current between two electrical lines Figure 6 shows the switch configuration in a third example of a connected error. In this example, this error scenario describes a macro error, i.e., an undesired electrical connection between the first electrical line 6a and the second electrical line 6b. The electrical resistance of the undesired electrical connection is specified as 5 Ω. The error control unit 10 creates a corresponding error description, which is named "Error 3" and is sent to the local node 8 with this name.
[0060] When analyzing the error description by the first local node 8a, since the set value for the first electrical line 6a is included in this error description, it is identified that the first local node 8a is involved in the connection of the error "Error 3". Based on a predefined rule known to the routine for creating drive control rules, it is further identified by the first local node 8a that this first local node 8a is responsible for the connection of the resistance specified in the error description. Accordingly, the first local node creates a drive control rule to allow current to flow in the first electrical line 6a without additional resistance and additionally form an electrical connection between the first electrical line 6a and the first error guide rail 12, and this drive control rule is stored in the first local memory 20a with the name "Error 3".
[0061] When analyzing the error description by the second local node 8b, since the set value for the second electrical line 6b is included in this error description, it is identified that the second local node 8b is involved in the connection of the error "Error 3". Based on a predefined rule, it is further identified by the second local node 8b that the second local node 8b is not responsible for the connection of the resistance specified in the error description. Accordingly, the second local node creates a drive control rule to allow current to flow in the first electrical line 6a without additional resistance and additionally form a resistance-free electrical connection between the second electrical line 6b and the first error guide rail 12, and this drive control rule is stored in the second local memory 20b with the name "Error 3".
[0062] When the trigger condition associated with "Error 3" is satisfied, the error control unit 10 immediately sends the execution instruction "Execution of Error 3" to the local node 8. Accordingly, the drive control rule stored under the name "Error 3" in the first local memory 20a is executed by the first local node 8a, and the drive control rule stored under the same name in the second local memory 20b is executed by the second local node 8b. In this way, according to the set value of the error scenario, the electrical connection of the first electrical line 6a to the second electrical line 6b guided through the first error guide rail 12 is obtained with an electrical resistance of 5 Ω.
Claims
1. A test bench (2) configured for subjecting a test subject (4) to simulated electrical errors, said test bench (2) including a central error control unit (10) for coordinating the simulated electrical errors, the test bench (2) comprises at least one first local node (8 a) configured to perform an error simulation triggered by the error control unit (10) by controlling a first switch device (16 a) to falsify a selected current, the error control unit (10) is adapted to create and transmit to the first local node (8 a) a first abstract error description specifying at least one first electrical error connected to a first electrical line (6 a); the first local node (8a) is configured to derive from the first abstract error description a first drive control law for the first switch device (16a) suitable for connecting the first electrical error to the first electrical line (6a); the first local node (8a) is configured to drive and control the first switch device (16a) according to the first drive control rule, thereby connecting the first electrical error to the first electrical line (6a); Test bench (2).
2. the first local node (8a) of the test bench (2) is designed as a modular component, in particular as a pluggable printed circuit board, A test bench (2) according to claim 1.
3. The error control unit (10) of the test bench (2) The test bench is configured to read a wiring description stored in the test bench in order to summarize the electrical error, the wiring description including at least the first electrical line (6 a).
3. A test bench (2) according to claim 1 or 2.
4. the error control unit (10) of the test bench (2) is configured to specify in the first abstract error description the first electrical error as a cable break, a short circuit, a leakage current to earth, a poor contact or a bounce pattern between the first electrical line (6a) and the second electrical line (6b), A test bench (2) according to claim 1.
5. the first electrical line (6a) of the test bench (2) is configured to conduct a current for transferring energy and / or information from the test subject (4) to the test bench (2) or for transferring energy and / or information from the test bench (2) to the test subject (4), A test bench (2) according to any one of the preceding claims.
6. the test bench (2) comprises an arrangement of error guide rails (12, 14), and the first local node (8a) is configured to form an electrical contact connection of the first electric line (6a) to the error guide rails (12, 14) by the drive control of the first switch device (16a), A test bench (2) according to any one of the preceding claims.
7. the arrangement of the error guide rails (12, 14) of the test bench (2) comprises parallel running error guide rails (12, 14) with different electrical properties, in particular one error guide rail (12, 14) optimized for conducting high current strengths and one error guide rail (12, 14) optimized for conducting electrical signals for information transmission, A test bench (2) according to claim 6.
8. The first local node (8a) of the test bench (2) is adapted to check the first abstract error description for feasibility and to return to the error control unit (10) a message of infeasibility of the first abstract error description, said check for feasibility in particular comprising at least one of the following checks: - a comparison of the switching times of at least one switch of said first switching device (16a) with time settings contained in said first abstract error description, - a comparison of the current tolerance of at least one switch of said first switch device (16a) with a current tolerance setting contained in said first abstract error description; and a comparison of the breakdown voltage of at least one switch of said first switch device (16a) with a voltage setting value contained in said first abstract error description, A test bench (2) according to any one of the preceding claims.
9. The entire switch device (16a) of the test bench (2), each of which is driven and controlled by a local node (8), includes mechanical switches and semiconductor switches; A test bench (2) according to any one of the preceding claims.
10. the first local node (8a) of the test bench (2) is configured to determine a first period of time necessary to connect the first electrical error and to transmit the first period of time to the error control unit (10); the error control unit (10) of the test bench (2) is configured to take the first period into account in said compilation, A test bench (2) according to any one of the preceding claims.
11. the test bench (2) comprises a second local node (8b) configured to perform an error simulation triggered by the error control unit (10) by controlling a second switch device (16b) to falsify a selected current, the error control unit (10) of the test bench (2) is configured to create and transmit to the second local node (8b) a second abstract error description specifying at least one second electrical error connected to a second electrical line (6b); the second local node (8b) derives from the second abstract error description a second drive control rule for the second switch device (16b) suitable for connecting the second electrical error to the second electrical line (6b); determining a second time period required to connect the second electrical error and transmitting the second time period to the error control unit (10); and connecting the second electrical fault to the second electrical line (6b) by driving and controlling the second switch device (16b) according to the second driving control rule; the error control unit (10) is configured to synchronize the connection of the first electrical error with the connection of the second electrical error taking into account the first period and the second period. A test bench (2) according to claim 10.