JPH04339437A - Multiple transmitting system diagnosing device - Google Patents

Abstract

PURPOSE:To surely diagnose the trouble generation of one side network, to surely relay a trouble generating signal to other side network and thus, to perform the suitable switching of a control method by the multiple node of other side network. CONSTITUTION:A gateway node 20 connected to multiple buses MB1 and MB2 of two systems is equipped with respective multiple buses MB1 and MB2 to connect the self-station, a micro processor 21, communication control circuits 22 and 23, driver receiver circuits 26 and 27 and driver receiver circuits 28 and 29 which diagnose the abnormality of respective multiple nodes 11-20 having the communication function connected to respective the multiple buses MB1 and MB2 and the trouble generating signal is relayed to other side network.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diagnostic apparatus using a multiplex transmission method for transmitting signals between multiple nodes connected to a plurality of networks.

0002

[Prior Art] Conventionally, this type of multiplex transmission system has been used as shown in FIG.
There is a system used in a system having two networks with different responsiveness (for example, transmission speed) as shown in FIG.
transmit signals to each other via the multiplex bus MB1, and in the second network N2, the multiplex nodes 10, 16 to 19 transmit signals such as data to each other via the multiplex bus MB2, and each performs its own control. ing.

[0003] The multiplex node 10 is a component of both networks, and in addition to the communication function described above, it also has the role of a gateway for relaying signals commonly used in both networks. Hereinafter, the multiplex node 10 will be referred to as a gateway node 10. The multiplex nodes 11 and 16 periodically transmit signals to each network, check reception response signals from each multiplex node, or have each multiplex node periodically transmit signals, etc. Check whether it is working properly. When a failure occurs in a multiple node, the multiple nodes 11 and 16 may receive no response signal or be unable to transmit at all if the multiple node in which the failure has occurred is in the same network, resulting in some type of failure. However, if it is a failure within another network, it cannot be detected at all. When a failure occurs, it is necessary to change the control method for each node, so the details of the failure must also be notified to other networks.

For example, if the multiplex node 15 of the first network N1 becomes unable to communicate due to a failure, the multiplex node 11 first detects the non-communicable state of the multiplex node 15 through periodic checks, and immediately returns to the first network N1. N1
A signal indicating the occurrence of a failure in the multi-node 15 is transmitted to the multi-node 15. The gateway node 10 relays the received failure occurrence signal to each of the multiplex nodes 16 to 19 of the second network N2. This allows each of the multiplex nodes 16 to 19 of the second network N2 to switch control methods. Note that multiple nodes within the first network N1 can also use this failure occurrence signal, and since the failure occurs within the same network N1, it is also possible to detect it by other means. The same applies when a failure occurs in a multiple node of the second network N2, the multiple node 16 detects the failure, and the gateway node 10 relays the failure occurrence signal to the first network N1.

[0005] The multiplex nodes 11 and 16 also have an emergency communication means that allows communication even if one line of the twisted pair cable forming the multiplex bus is short-circuited, and an emergency communication means that allows communication when both lines of the twisted pair cable are normal. The multiplex node 11 periodically checks whether there is any abnormality in the multiplexed bus, and if an abnormality is found in the networks N1 and N2 during these regular checks, the multiplexed node 11 and 16, for example, by lighting up a warning lamp in the meter to notify the operator of an abnormality, or if an abnormality occurs but is relatively not dangerous, it may be memorized that there has been an abnormality and repairs can be made at a later date. It is also possible to output abnormality history information when the device is brought into a factory or the like.

The above multiplex transmission system is used for signal transmission in vehicles such as automobiles, and is intended to reduce the number of wiring lines and simplify the system. FIG. 5 is a diagram showing an example of an automotive multiplex transmission system having two networks with different responsiveness (for example, transmission speed). In the figure, multiple transmission lines (multiple buses) MB11 to MB14 and MB21 to
The MB23 is made up of twisted pair cables and the like, connected by connectors C1 to C8, and wired in two loops to perform balanced signal transmission.

[0007] The multiplex bus MB11 is incorporated, for example, in a wiring harness that runs inside the dashboard.
Multiple nodes 10 to 12, which are control units with communication functions, are connected. The multiplex bus MB12 is
For example, it is built into a wire harness that runs inside an instrument panel, and multiple nodes 13 and 14 having communication functions are connected thereto. Multiple bus MB
13 is built into a wire harness that runs through the floor next to the seat, for example, and is connected to a multiple node 15 that also has a communication function. Therefore, multiple nodes 10-15
The multiplexed buses MB11 to MB14 constitute a first network, and the multiplexed nodes 10 to 15 have the same responsiveness, and communicate via the multiplexed buses MB11 to MB14, thereby allowing mutual signal transmission. It becomes possible.

[0008] The multiplex bus MB21 is incorporated, for example, in a wiring harness that runs inside the dashboard.
Similarly, multiple nodes 10, 16-18 having communication functions are connected. The multiplex bus MB23 is built into, for example, a wire harness that runs through the floor next to the seat, and is connected to a multiplex node 19 that also has a communication function. Therefore, multiple nodes 10, 16 to 19 and multiple bus MB2
1 to MB23 constitute a second network, and the multiplex nodes 10 and 16 to 19 each have the same responsiveness (different responsiveness from the multiplexed nodes 11 to 15), and the multiplexed buses MB21 to MB23 By communicating with each other, it becomes possible to transmit signals to each other.

The multiplex node 10 is also a gateway node that relays signals commonly used by both networks. In the case of such a system configuration, for example, the first network is used for communication such as switch signals operated by the driver and actuator control signals generated accordingly, and the second network is used for communication such as signals from switches operated by the driver and control signals for actuators generated accordingly, and the second network is used for communication such as signals from switches operated by the driver and control signals for actuators generated accordingly. It is also used for communication of signals that are exchanged between multiple nodes such as brakes and requires relatively high reliability.

[0010] As described above, in a system equipped with two types of networks, it is necessary to take into consideration the failures of each multiple node or multiple bus and to have a failure diagnosis ability. Furthermore, when handling signals related to control of engines, brakes, etc., high reliability is required, so a higher-performance fault diagnosis function is essential. For example, in the fault diagnosis function, when a fault is detected, the driver is warned of the fault and the control of the engine, brakes, etc. is switched to emergency control that does not use a network.

[0011]

However, in the above-mentioned diagnostic device, when a failure occurs in the communication function of the gateway node, the failure occurrence signal is transmitted to the other network because the gateway node with the relay function has failed. Therefore, even though a failure has occurred, multiple nodes in the other network cannot appropriately switch the control method. Also, if a failure occurs in the multiplex bus, for example, if the connector connecting the multiplex bus and multiple nodes becomes disconnected,
If two cables of a multiplexed bus are short-circuited, no failure signal is generated, so the multiplexed node on the other network cannot switch the control method appropriately, similar to the above problem. Ta.

The present invention has been developed in view of the above problems, and is capable of reliably diagnosing the occurrence of a fault in one network, reliably relaying a fault occurrence signal to the other network, and achieving high reliability in multiplex transmission. The purpose of the present invention is to provide a diagnostic device using a multiplex transmission method that can obtain high performance.

[0013]

[Means for Solving the Problems] In order to achieve the above object, the present invention has at least two transmission lines to which a plurality of multiplex nodes having communication means are connected, and each of the multiplex nodes is connected to the same A multiplexer that transmits signals through transmission paths of a system, at least one of the multiplex nodes is connected to transmission paths of multiple systems among the transmission paths, and transmits signals between the transmission paths. In the transmission system, at least one multiple node connected to the plurality of transmission lines includes an abnormality diagnosis means for diagnosing an abnormality in each transmission line to which the multiple node is connected and each multiple node connected to each transmission line. A multiplex transmission type diagnostic device is provided.

[0014]

[Operation] Multiple nodes connected to transmission lines of multiple systems diagnose abnormalities in each transmission line and multiple nodes, and transmit the diagnosis results to networks of the same system or other systems as necessary. Therefore, each multiplex node can appropriately switch the control method.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to FIGS. 1 to 3. FIG. 1 is a block diagram showing an example of the configuration of a gateway node according to the present invention. Note that the configuration of the multiplex transmission system is the same as that shown in FIGS. 4 and 5.

In the figure, the gateway node 20 is
Microprocessor (CPU) 2 that controls overall processing
1 is connected to two communication control circuits (LSI) 22 and 23 consisting of a multiplex transmission control IC for controlling transmission between networks, a buffer for transmission and reception, an interface, and the like. Further, a driver/receiver circuit (D/R) 26 and a diagnostic D/R 28 are connected to the LSI 22 via a switch 24, and a switch 2 is connected to the LSI 23.
A D/R 27 and a diagnostic D/R 29 are connected through the D/R 5 and the D/R 29, respectively.

The switch 24 is a D/R 26 or a diagnostic D
/R28 to LSI22, CP
Switching is controlled by U21. switch 25
Similarly, D/R27 or diagnostic D/R29 can be
23, and switching is controlled by the CPU 21. D/Rs 26 and 27 are circuits that interface the multiplex buses MB1 and MB2 with the LSIs 22 and 23, respectively, and are configured to ensure communication even if the multiplex buses fail in short mode.

Diagnostic D/R28, 29 are D/R26,
27, multiplex buses MB1, MB2 and LSI respectively.
22 and 23, and is configured so that signals can be transmitted and received with each multiplex node only when both wires of the multiplex bus made of twisted pair cables are normal. The CPU 21 is normally D/
Switches 24 and 25 so that R26 and 27 are selected
However, the switches 24 and 25 are periodically switched and controlled, and the diagnostic D/Rs 28 and 29 are used to check whether signals are being transmitted and received normally. If either of the signals cannot be transmitted or received when using the diagnostic D/R 28, 29, the CPU 21
diagnoses that there is an abnormality in one of the twisted pair cables of multiplex bus MB1 or MB2.

Therefore, in this embodiment, the diagnostic D/Rs 28 and 29 can be used even if, for example, the connector connecting the multiplex bus to the multiplex node is disconnected or the twisted pair cable is short-circuited. A fault diagnosis function that sends and receives signals can diagnose the location of a fault. In addition to its original control function, the CPU 21 also periodically monitors the operations of both networks N1 and N2. That is, the multiplex node 20 periodically transmits signals to both networks N1 and N2, checks reception response signals from each multiplex node, or causes each multiplex node to periodically transmit signals. The system diagnoses whether each multiplex node is operating normally.

Next, an embodiment of the network diagnosis method performed by the gateway node 20 will be described based on the flowcharts of FIGS. 2 and 3. LSI22,23
Based on the operation control of the CPU 21, both networks N
Response signals are periodically received from all the multiplex nodes including the own stations 1 and N2, and are stored as response data in the reception buffer for each network.The CPU 21 takes in the response data and sends responses from all the multiplex nodes. It is determined whether a signal has been transmitted (step 101). and,
If no response signal is transmitted from any of the multiplex nodes, it is determined which network the response signal is not transmitted from (step 102).

[0021] Here, if the network to which no response signal is transmitted is network N1, then the multiplex node that does not transmit a response signal is determined based on the captured response signal (steps 103 to 107). This judgment is
The determination is made based on the ID data (data consisting of an address indicating the own station, an address indicating the destination, data length, etc.) of the reception response signal. As a result of the above judgment, CP
U21 recognizes which of the multiplex nodes 10 to 15 the received reception response signal is from (steps 108 to 15).
113). Furthermore, if the network to which the response signal is not transmitted is network N2, similarly to the above, a multiple node that does not transmit the response signal is determined based on the ID data of the captured response signal (steps 114 to 117).
. As a result of the above judgment, the CPU 21 recognizes which of the multiplex nodes 10, 16 to 18 receives the received reception response signal (steps 118 to 122).

Steps 108-113, 118-122
When the CPU 21 recognizes a multiple node that does not transmit a response signal, it performs a fault diagnosis based on the fault detection (
Step 123), the diagnosis result is written and stored in the internal memory of the CPU 21 as a failure history of the multiple nodes that do not transmit the response signal (Step 124). Further, the CPU 21 determines which multiple nodes require a failure occurrence signal according to the diagnosis result (step 1).
25) Using the diagnostic result data stored in the internal memory, create a fault occurrence signal consisting of ID data, data corresponding to the diagnosis result, etc., and send the fault occurrence signal to the network of LSIs 22 and 23. Write to the transmit buffer (step 126).

As a result, when the LSIs 22 and 23 finish writing the failure occurrence signal into the transmission buffer, the failure occurrence signal in the transmission buffer is transferred to the network N1 which requires the failure occurrence signal according to the ID data. ，
It is transmitted to N2 multiple nodes (in this case, all nodes except the failed multiple node) (step 127). The above-mentioned failure occurrence signal may be sent first to the network where the failure has occurred, and then to other networks, or
Furthermore, since each multi-node can independently detect a failure within the network, it may go only to networks where no failure has occurred. Then, when the transmission of the failure occurrence signal is finished, the above processing operation is finished.

Therefore, in this embodiment, if the communication function of the gateway node 20 with respect to the network N1 fails, the gateway node 20 performs a periodic check to determine if the communication function of the gateway node 20 with respect to the network N1 fails. It is possible to detect that the communication function of the network N2 is abnormal and immediately send a failure occurrence signal to the network N2.

Next, a case will be described in which the gateway node 20 is used in an automobile multiplex system. The gateway node 20 is a control unit connected to or built into a joint box located near the instrument panel. In the above joint box,
Multiple wire harnesses wired to the vehicle are connected. In the example of FIG. 5, the wire harness inside the dashboard in which the multiplex buses MB12 and MB21 are built in, the wire harness inside the dashboard in which the multiplex bus 11 is built in, and the electrical components in the engine room shown by dotted lines are connected. The ends of the wire harness are also connected.

[0026] Signal lines (
The multiple buses (including multiple buses) are connected to a branch circuit formed by a bus bar inside the joint box, and branch to other wiring harnesses and multiple nodes 20 built in (or connected to) the joint box. However, since some of the signal lines do not require branching, some signal lines are directly connected to the multiplex node 20 without going through a bus bar.

[0027] Furthermore, the power lines in each connected wire harness are also similar to the signal lines. Furthermore, some of the power lines are connected by fuses installed in the joint box.
Protected from accidents such as short circuits. Further, the joint box or multiple node 20 is also equipped with switching elements (relays, transistors), and circuits of some of the electrical components are opened and closed by the switching elements.

The multiplex node 20 is thus capable of inputting signals from the wire harness and receiving signals via the multiplex bus, and controls the switching elements based on these signals to control the electrical components. or transmit signals to other multiple nodes via multiple buses. The reason why the network diagnostic function described above was provided in the multi-node 20 built in (or connected to) the joint box is because the joint box has functions such as power protection and power/signal distribution, so many wire harnesses are connected to it. This is because there is. Further, even wire harnesses that cannot be directly connected are often connected to a directly connected wire harness very close to the joint box for the same reason. In the example of FIG. 5, this is a wire harness that runs under the floor next to the driver's seat in which the multiplex buses MB13 and MB22 are installed. Although the above wire harness cannot be directly connected to the joint box where the multiplex node 20 is located, the multiplex buses MB11 and MB21 are connected to the connectors C3 and C6 very close to each other.
is connected to the built-in wiring harness.

[0029] In this way, when multiple networks are configured, the multiplex node 20 is connected directly to the wire harness in which the multiplex buses of each network are incorporated, or when the wires are wired very close to each other. will increase. Therefore, when attempting to provide the multiplex node 20 with a function of relaying signals from each network, the multiplex bus built into the wire harness that is already connected or the wire harness that is wired very close to each other must be connected. That's all you need and it's efficient.

For example, in FIG. 5, if we consider the case where another network is configured by placing several new multiplex nodes in the engine room, the multiplexed bus of this network is incorporated into the wire harness shown by the dotted line. Therefore, when connecting the multiplex node 20 to the above-mentioned network to provide a relay function, since the above-mentioned wire harness is already connected, it is only necessary to branch the multiplex bus and connect it to the multiplex node 20. It turns out. When trying to connect a multiplex bus to a multiplex node with a relay function, it is more efficient to provide the relay function in the multiplex node 20, compared to the case where the multiplex bus must be newly incorporated into several wire harnesses. Recognize. In this way, it can be said that the multiplex node 20 is an optimal node for the relay function. Therefore, the multiplex node 20 is most suitable as a multiplex node that provides diagnostic functions for both networks.

Therefore, in this embodiment, since the multi-node 20 having the gateway function is provided with a fault diagnosis function, when a fault occurs, a fault occurrence signal can be sent to the normal network. , the control method can be appropriately switched. Furthermore, since the gateway node 20 can grasp all the transmitted and received signals in the data transmission system and can directly obtain the data transmitted on the data buses 10a and 20a, by adding a fault diagnosis function to the gateway node 20, unnecessary This eliminates the need to transmit fault information, making it possible to diagnose faults in the entire system. In addition, in this example, 1
By concentrating the fault diagnosis function on one gateway node 20, a part of the algorithm for fault diagnosis can be shared, so that when considered comprehensively, the effect of reducing the load on multiple nodes can be expected.

[0032]

As explained above, the present invention has at least two transmission lines to which a plurality of multiple nodes having communication means are connected, and each of the multiple nodes communicates via the transmission line of the same system. In a multiplex transmission system in which signal transmission is performed, and at least one of the multiplex nodes is connected to a plurality of transmission paths among the transmission paths, the plurality of multiplex nodes transmit signals between the transmission paths. At least one multiple node connected to a transmission line of the system is equipped with an abnormality diagnosis means for diagnosing an abnormality in each transmission line to which the multiple node is connected and each multiple node connected to each transmission line. It is possible to reliably relay the fault occurrence signal to the other network, and high reliability of multiplex transmission can be obtained, thereby making it possible to improve the efficiency of data transmission.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an example of the configuration of a gateway node according to the present invention.

FIG. 2 is an example of a flowchart for explaining processing operations in failure diagnosis of the gateway node shown in FIG. 1;

FIG. 3 is an example of a flowchart for explaining processing operations in failure diagnosis of the gateway node shown in FIG. 1;

FIG. 4 is a configuration block diagram showing the configuration of a multiplex transmission system.

FIG. 5 is a diagram showing an example of an automotive multiplex transmission system.

[Explanation of symbols]

N1, N2 Network MB1, MB2 Multiplex transmission line (multiple bus) 11 to 19
Multiple nodes 10, 20 Multiple nodes (gateway node) 21
CPU 22, 23 Communication control circuit (LSI) 24, 25
Switches 26, 27 Driver/receiver circuit (D/R) 28
,29 Diagnostic D/R

Claims (2)

[Claims] 1. At least two systems of transmission paths are connected to which a plurality of multiplex nodes having communication means are connected, each of the multiplex nodes transmits signals via the transmission path of the same system, and each of the multiplex nodes At least one of the multiplex nodes is connected to a plurality of transmission lines among the transmission lines, and in a multiplex transmission method for transmitting signals between the transmission lines, at least one of the multiplex nodes connected to the plurality of transmission lines is connected to the plurality of transmission lines. 1. A diagnostic device for a multiplex transmission system, characterized in that each of the multiplex nodes is equipped with an abnormality diagnosis means for diagnosing an abnormality in each transmission path to which the multiplex node is connected and each multiplex node connected to each of the transmission paths. 2. The abnormality diagnosing means, when used in a multiplex transmission system for an automobile, is arranged near an instrument panel and is provided at a connection part to which a plurality of wire harnesses are connected. 2. A diagnostic device using a multiplex transmission method according to item 1.