KR20040053888A - Method of self-diagnosis in can network system for a vehicle - Google Patents

Abstract

PURPOSE: A device for the self-diagnosis on a car CAN(Controller Area Network) system is provided to largely save a card design/manufacturing cost and keep a merit of the CAN system by performing the self-diagnosis as connecting a self-diagnosis device to a CAN bus line connected to the ECUs(Electronic Control Unit). CONSTITUTION: A communication cycle of a message transmitted from the self-diagnosis device is compared with the preset communication cycle(S20). In case that both communication cycles are identical with each other, a normal control mode is performed(S30). In the case that the both communication cycles are identical, the normal control mode is stopped and the self-diagnosis is ready(S40). The self-diagnosis is performed by a self-diagnosis signal transmitted from the self-diagnosis device(S50). It is judged that the message is received in a maximum communication cycle(S60). In the case that the message is not received in the maximum communication cycle, the self-diagnosis mode is cancelled(S70).

Description

Self-diagnosis method in vehicle can network system {METHOD OF SELF-DIAGNOSIS IN CAN NETWORK SYSTEM FOR A VEHICLE}

The present invention relates to a self-diagnosis method in a vehicle can network system, and in particular, a self-diagnosis in a vehicle can network system that enables self-diagnosis using an existing canvas line connected to a plurality of electronic control units in a can network system. It is about a method.

Recently, as the control system becomes more complicated and intelligent, and the performance of semiconductor devices such as microprocessors is improved and the price is lowered, the demand for a distributed control system is gradually increased, and the necessity for a real-time network for control is highlighted. As a communication network supporting communication of such a control real-time network, there is a CAN (Controller Area Network). The CAN was originally developed as an in-vehicle network protocol in the 1980s, and is excellent in performance and inexpensive, and is designated as an international standard for serial communication protocol ISO11898 by ISO, and is actively applied to other industrial fields. In particular, due to the high data processing speed of CAN, strong immunity to electrical disturbances and the ability to detect and correct errors, CAN is widely known as a system that can be widely used in various industrial fields such as manufacturing, aviation, and railway.

The CAN communication protocol defines a method of exchanging information between communication terminals defined based on the OSI reference model of ISO. Among the seven layers of OSI, the architecture of CAN is defined across the lower two physical layers and the data link control layer. . In addition, the CAN may uniquely assign an identifier indicating a bus access priority according to the message type. In this case, the lower the number of identifiers, the higher the priority. This identifier prevents the message from colliding. Through the arbitration method of "Non-Destructive-Bitwise", the highest priority message among the collided messages can use the bus without any delay and real-time data. Suitable for the transmission of

1 is a functional block diagram illustrating self-diagnosis in a conventional vehicle can network system.

As shown in FIG. 1, in a conventional vehicle CAN network system, a plurality of electric control units (ECUs) E1 to En mounted in place in a vehicle and connected to a CAN bus line are connected. In order to self-diagnose, a unidirectional communication line called a K-Line is connected to each of the electronic control units E1 to En, and a multi-user self tester (MUT) such as a high-scan (HI-SCAN) 1 ) Is connected to the K-Line and communicates with each of the electronic control units (E1 ~ En) through this to transmit various diagnostic results to the vehicle self-diagnosis machine (1). In addition, between the K-Line and the self-diagnostic machine (1) is provided with a K-Line interface unit (2) that serves as a link to transfer their communication.

However, when the self-diagnosis is performed by connecting the self-diagnostic apparatus 1 to the conventional K-Line configured as described above, a process of initializing communication environment variables for the K-Line interface unit 2 is required. Dedicated hardware such as the line interface unit 2 must be implemented, which not only increases the manufacturing cost but also requires the K-line wiring for connecting the respective electronic control units (E1 to En), which complicates the assembly inside the vehicle. As a result, the design and manufacturing process of the vehicle is complicated.

The present invention has been made to solve the above-mentioned problems, an object of the present invention is to carry out the self-diagnosis by connecting the self-diagnostic machine to the existing canvas line connected to a plurality of electronic control unit in the vehicle can network system, It is not necessary to implement the hardware of K-Line for diagnosis, which greatly reduces the vehicle design and manufacturing cost, and also enables the vehicle to maintain the advantages of the can network system such as no initialization, fast communication speed, and multiple communication. The present invention provides a self-diagnosis method in a can network system.

In order to achieve the above object, a self-diagnosis method in a vehicular can network system of the present invention includes a constant communication in the self-diagnostic apparatus in a state in which a vehicular self-diagnostic apparatus is connected to a canvas of a can network system to which a plurality of vehicular electronic control units are connected. A self-diagnosis method in a vehicle can network system performed by each of the electronic control units after transmitting an arbitrary message having a period, the method comprising: (a) a communication period of a message sent from the self-diagnostic device and a communication period stored in advance; Comparing the same; (b) performing a normal control mode when the communication period of the message and the previously stored communication period are not the same as a result of the determination in step (a); (c) stopping the normal control mode and preparing to enter the self-diagnosis mode when the communication period of the message is the same as the previously stored communication period as a result of the determination in step (a); (d) performing self-diagnosis according to the self-diagnosis signal sent from the self-diagnosticer; (e) determining whether the message has been received within a maximum communication period; (f) returning to step (d) if the message is received within the maximum communication period as a result of the determination in step (e); And (g) releasing the self-diagnosis mode when the message is not received within the maximum communication period as a result of the determination in step (e).

In the above configuration, the maximum communication period is preferably made a multiple of the arbitrary message communication period.

1 is a functional block diagram illustrating self-diagnosis in a conventional vehicle can network system;

2 is a functional block diagram illustrating self-diagnosis in a vehicle can network system according to an embodiment of the present invention;

3 is a flowchart illustrating a self-diagnosis method in a can network system for a vehicle according to an embodiment of the present invention.

*** Explanation of symbols on main parts of drawing ***

100: self-diagnosis machine, E10 ~ En: electronic control unit (ECU)

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. This embodiment is not intended to limit the scope of the invention, but is presented by way of example only.

2 is a functional block diagram illustrating self-diagnosis in a vehicle can network system according to an embodiment of the present invention.

As shown in FIG. 2, the vehicle can network system of the present invention includes a plurality of electronic control units (eg, airbag electronic control units) mounted in place in a vehicle and connected by canvas lines to control respective functions of the vehicle. Car A / V electronic control unit) (E10 to En).

In such a can network system, various diagnostics of the respective electronic control units E10 to En, for example, the state and abnormality of each vehicle parts (engine, suspension, power steering, antilock brake system, etc.) In order to check the presence, the self-diagnosis may be performed simply by connecting the vehicle self-diagnostic apparatus 100 on the canvas line.

In the above-described configuration, the vehicle self-diagnostic apparatus 100 is a device for monitoring the operating state of a well-known electronic device, Korean Utility Model Publication No. 1996-015297 (Automotive Self-Diagnostic Machine), Korean Patent Publication No. 1998 -074844 (car portable diagnostic device of the vehicle) and Korean Patent Publication No. 1995-0029767 (self-diagnostic device for automobile) and the like.

Hereinafter, the operation of the self-diagnosis method in the vehicular can network system of the present invention having the above-described configuration will be described in detail.

3 is a flowchart illustrating a self-diagnosis method in a can network system for a vehicle according to an embodiment of the present invention. First, a self-diagnostic apparatus 100 is connected and communicated on a can network. Define an arbitrary message (eg, "Tester Present", etc.), and define a maximum communication period for the arbitrary message as a multiple of the communication period (ie, 2 times, 3 times, ..., N times). Let's do it.

As shown in FIG. 3, in step S10, a connector (not shown) of the self-diagnostic apparatus 100 is connected on a canvas of a network to transmit the above arbitrary message.

Next, the process proceeds to step S20 where each electronic control unit E10 to En determines whether the communication period of the message sent from the self-diagnostic machine 100 and the communication period previously stored in each of the electronic control units E10 to En are the same. That is, it is determined whether it is in the self-diagnosis mode.

As a result of the determination in step S20, when the communication period of the message sent from the self-diagnostic apparatus 100 and the communication period stored in advance in each of the electronic control units E10 to En are not the same, the process proceeds to step S30 to determine each electronic control unit ( E10 to En), the normal control mode is performed, and the flow returns to step S20.

On the other hand, if it is determined in step S20 that the communication period of the message sent from the self-diagnostic apparatus 100 and the communication period stored in advance in each of the electronic control units E10 to En are the same, the process proceeds to step S40 and the respective electronic control units. (E10 ~ En) stops the normal control mode and prepares to enter the self-diagnosis mode.

Next, the process proceeds to step S50, and each electronic control unit E10 to En performs self-diagnosis according to the self-diagnosis signal sent from the self-diagnostic apparatus 100.

Subsequently, the process proceeds to step S60 where each electronic control unit E10 to En determines whether the message sent from the self-diagnostic apparatus 100 has been received within the maximum communication period.

As a result of the determination in step S60, when the message sent from the self-diagnostic apparatus 100 is received within the maximum communication period, the process returns to step S50 and each electronic control unit E10 to the self-diagnostic signal sent from the self-diagnostic apparatus 100. En) continues the self-test.

On the other hand, if it is determined in step S60 that the message sent from the self-diagnostic apparatus 100 has not been received within the maximum communication period, the flow proceeds to step S70 and the self-diagnostic apparatus 100 is absent in each of the electronic control units E10 to En. After the self-diagnosis mode is determined to be determined to be, the process returns to step S20.

Although a preferred embodiment of a self-diagnosis method in a vehicle can network system according to the present invention has been described above, the present invention is not limited thereto, but the scope of the claims and the detailed description of the invention and the accompanying drawings are various. It is possible to carry out the transformation to this also belongs to the present invention.

According to the self-diagnostic method in the vehicle can network system of the present invention as described above, by performing a self-diagnosis by connecting the self-diagnostic machine on the existing canvas line connected to a plurality of electronic control units in the vehicle can network system, Because wiring is not required to implement K-Line's dedicated hardware for self-diagnosis, the design and manufacturing process of the vehicle is reduced, the manufacturing cost can be greatly reduced, and there is no need for initialization, fast communication speed and multiplexing. There is an advantage that can maintain the advantages of can network system such as communication.

Claims (2)

Vehicle cans performed by each electronic control unit after transmitting a random message having a predetermined communication period from the self-diagnosticer while the vehicle self-diagnosticer is connected to the canvas of a can network system to which a plurality of vehicle electronic control units are connected. In the self-diagnosis method in a network system, (a) comparing the communication period of the message sent from the self-diagnosticer with a pre-stored communication period; (b) performing a normal control mode when the communication period of the message and the previously stored communication period are not the same as a result of the determination in step (a); (c) stopping the normal control mode and preparing to enter the self-diagnosis mode when the communication period of the message is the same as the previously stored communication period as a result of the determination in step (a); (d) performing self-diagnosis according to the self-diagnosis signal sent from the self-diagnosticer; (e) determining whether the message has been received within a maximum communication period; (f) returning to step (d) if the message is received within the maximum communication period as a result of the determination in step (e); And (g) if the message is not received within the maximum communication period as a result of the determination in step (e), the self-diagnosis method comprising the step of releasing the self-diagnosis mode. . 2. The method of claim 1, wherein the maximum communication period is a multiple of the arbitrary message communication period.