KR20050075086A - Communication interface using one chip microcomputer and motorcar condition display apparatus - Google Patents

Abstract

The present invention relates to a communication interface using a one-chip microcomputer and an automobile state display device having the integrated device, the communication interface comprising: an ECU connector for connecting an electronic control unit (ECU) and a communication interface; A first voltage level, one end of which is connected to the ECU connector and the other end of which is connected to a communication speed converter, for converting a voltage level of a communication protocol used in the electronic control unit (ECU) into a voltage level used in the communication speed converter; A conversion unit; One end is connected to the first voltage level converter and the other end is connected to the second voltage level converter to convert a communication speed of a communication protocol used in the electronic control unit (ECU) into a communication speed of general computer serial communication. A communication speed converter; A second voltage level converter connected at one end to the communication speed converter and at the other end to a terminal connector to convert a voltage level used in the communication speed converter to a voltage level of general computer serial communication; And a terminal connector connected to the second voltage level converter and configured to connect a communication interface with a computer.

Description

Communication interface using one chip microcomputer and vehicle condition display apparatus having same {Communication interface using one chip microcomputer and motorcar condition display apparatus}

The present invention relates to a communication interface and a vehicle status display device having the same, and in particular, a communication interface using a one-chip microcomputer that enables communication between an electronic control unit (ECU) and a general computer, and the communication interface is integrally provided. And it relates to a vehicle state display device for always displaying the state of the vehicle stored in the electronic control unit.

Most automobiles currently on the market include: an engine ECU (Engine ECU) for receiving detection signals from various sensors and controlling the operation of the engine based on the detection signals; A / TM ECU (Automatic Transmission ECU) for controlling the operation of the automatic transmission; Many kinds of Electronic Control Units (ECUs), such as the ABS ECU (Anti-lock Break System ECU), which control the operation of the brakes, are embedded.

Each of the plurality of electronic control units (ECU) as described above has a self diagnosis function using a micro computer, and thus detects a state of a function of a device to be diagnosed and then corresponds to the diagnosis. The code is stored in the internal memory, and the diagnostic code stored in the electronic control unit (ECU) is output to the outside by various methods. In this case, the electronic control unit (ECU) outputs a diagnostic code according to a predetermined protocol (for example, DTC code system), and for this purpose, the diagnostic code system is stored in a predetermined storage medium and then outputs a predetermined diagnostic code based on the diagnostic code system. Will be stored in its own memory.

Automotive diagnostic devices belong to the power / wire harness diagnosis, and are generally classified into ON BOARD Diagnosis I and Off Board Diagnosis II.

On-board Diagnosis continuously diagnoses the abnormality of the device to be diagnosed by the electronic control unit (ECU), and if any abnormality occurs, it operates the backup or fail safe function and processes the data. Is a device for storing code in a self-contained memory, and off-board diagnosis is a failure diagnosis device installed in a repair shop or a service factory that reads out a digging code stored in the on-board diagnosis and outputs maintenance instructions. In addition, it is a device that facilitates the diagnosis and repair of the vehicle by continuously and automatically diagnose the status of the diagnosis target device by the electronic control unit (ECU).

Such a conventional vehicle diagnostic apparatus has a problem in that it is possible to read the diagnostic code value only by connecting an off board diagram installed in a service factory to an abnormality of the vehicle detected by the on board diagram. In other words, the on-board diagnosis and the off-board diagnosis are separated from each other, so it is impossible to know whether the car is abnormal until the driver visits the service factory and decodes the diagnosis code. There is a problem that can not respond quickly to the problem of the car because you can not take prompt action and must visit a repair shop.

1 is a schematic diagram showing a general vehicle inspection system.

The vehicle 10 continuously diagnoses an abnormality of a device to be diagnosed, and if an error occurs, operates the backup or fail safe function, processes it, and codes the data of the failure and stores it in a memory provided therein. (ECU) 12 is provided. On the other hand, the car repair shop or the service factory 20 reads the code stored in the memory of the electronic control unit (ECU) 12 to detect the failure state of the vehicle and the maintenance instructions. Equipped.

If a failure occurs while driving the car 10, the driver will grasp the failure state and take action if it can be done directly, and if it is unable to take action or determine the cause of the failure, the nearest car repair shop 20 Visit. In the auto repair shop 20, the fault diagnosis device 22 is connected to an electronic control unit (ECU) 12, which is embedded in the vehicle 10 and stores the state of the vehicle in a memory, and stored in the memory. Read out. The repairman checks the code displayed on the failure diagnosis device 22, finds out which part of the vehicle is in a broken state, and starts repair.

On the other hand, since the failure diagnosis device 22 is a device that indicates only the failure state of the vehicle by a code, the detailed state of the vehicle cannot be known. Therefore, a PC (Personal Computer) 24 is normally connected to the failure diagnosis device 22 and then read from the electronic control unit 12 stored in the memory of the failure diagnosis device 22 using RS232 communication. Data relating to the vehicle state is read into the PC 24. Therefore, the repairman can grasp the detailed state of the vehicle through the screen of the PC 24 and take appropriate measures.

The above-mentioned general vehicle inspection system firstly reads codes stored in an electronic control unit (ECU) of a vehicle to a troubleshooting device, and then reads the data of the troubleshooting device to a PC. The detailed state of can be seen.

According to the above-described general vehicle inspection system, if a car breakdown occurs while driving, a problem must be visited at a car repair shop equipped with the above-mentioned fault diagnosis device so that the fault can be diagnosed quickly. Even if the failure part of the vehicle is identified by using a diagnosis device, only the code for the failure is output to the failure diagnosis device, so that detailed information on the state of the vehicle cannot be known. There is a problem in that it is inconvenient to read data stored in the memory after accessing the secondary computer.

Therefore, in order to solve these problems, a method of directly outputting the data stored in the memory of the electronic control unit (ECU) to the PC by directly connecting the electronic control unit (ECU) recording the state of the vehicle to the PC. Research is underway. The above-described method of determining the state of the car by directly connecting the electronic control unit (ECU) and the PC can be performed by the driver because the driver can grasp the state of the car without visiting the auto repair shop. This is because there is an advantage in that it is convenient to manage the car because it is possible to directly deal with the troubles that can be dealt with without visiting the auto repair shop and know the condition of the car at any time.

In general, however, the electronic control unit (ECU) and the external modem are designed to exchange information by any one of ISO9141, SAE J1850, and CAN communication protocols, whereas PCs, laptops, and personal digital assistants (PDAs) are used. Computers such as this are designed to exchange information with an external modem using RS232 serial communication, but they are not possible to exchange information by connecting directly because communication speed, voltage level, etc. are different.

An object of the present invention is to provide a communication interface using a one-chip microcomputer that enables communication between an electronic control unit (ECU) and a general computer.

Another object of the present invention is to provide a vehicle state display device having a communication interface which is provided integrally with the communication interface and receives the state of the vehicle from the electronic control unit.

Communication interface using a one-chip microcomputer according to the present invention for achieving the above object, ECU connector for connecting the communication interface with the electronic control unit (ECU); One end is connected to the ECU connector and the other end is connected to a communication speed converter to convert the voltage level of the communication protocol used in the electronic control unit (ECU) to the voltage level used in the communication speed converter, or vice versa. A first voltage level converting unit converting a voltage level used in the communication speed converting unit into a voltage level of a communication protocol used in the electronic control unit (ECU); One end is connected to the first voltage level converter and the other end is connected to the second voltage level converter to convert the communication speed of the communication protocol used in the electronic control unit (ECU) into the communication speed of general computer serial communication. Or, conversely, changing a communication speed of general computer serial communication to a communication speed of a communication protocol used in the electronic control unit (ECU); One end is connected to the communication speed converter and the other end is connected to the terminal connector to convert the voltage level used in the communication speed converter to a voltage level of general computer serial communication, or vice versa. A second voltage level converting unit converting the voltage level used in the communication speed converting unit; And a terminal connector connected to the second voltage level converter and configured to connect a communication interface with a computer.

According to one embodiment of the invention, the communication speed conversion unit is preferably composed of a one-chip microcomputer, such as PIC16C06 or PIC16F84, the first voltage level conversion unit is a circuit composed of a plurality of transistors and resistors, the second The voltage level converter is preferably configured as a MAX 232 IC.

In addition, it is preferable that the communication protocol used in the electronic control unit (ECU) is ISO9141, and the serial communication supported by the computer is RS232.

According to another aspect of the present invention, there is provided a vehicle status display apparatus including a communication interface, the communication interface enabling communication between an electronic control unit and an external device; And a liquid crystal display which is integrally connected with the communication interface and which displays a state of the vehicle.

In this case, the communication interface preferably includes a first voltage level converter, a communication speed converter, and a second voltage level converter.

Therefore, according to the present invention, since the communication interface is constructed by using a one-chip microcomputer, the manufacturing cost is low, and the user can frequently diagnose the failure of the vehicle and diagnose the condition of the vehicle at the price of one communication interface. You can run

Hereinafter, a communication interface using a one-chip microcomputer and an automobile state display device having the same according to the present invention will be described in detail with reference to the accompanying drawings.

2 is a configuration diagram of a communication interface using a one-chip microcomputer according to the present invention, which is a communication interface enabling direct communication between an electronic control unit (ECU) and a general computer.

The communication interface 100 according to the present invention largely converts voltage levels of communication protocols used in the electronic control unit (ECU), for example, ISO1841, SAE J1850, CAN, to voltage levels used in the communication speed converter 130. On the contrary, the first voltage level converter 120 converts the voltage level used in the communication speed converter 130 into the voltage level of the communication protocol used in the electronic control unit (ECU), and the electronic control unit ( Converts the communication speed of the communication protocol used in the ECU into a communication speed of serial communication such as RS232 of a general computer, or conversely, converts the communication speed of RS232 serial communication of a general computer into the communication protocol used in the electronic control unit (ECU). Communication speed conversion unit 130 for changing the communication speed of the communication speed conversion unit 130 and the RS232 serial communication of a general computer To convert a voltage level, or consists of reversing the voltage level of the RS232 serial communication of general computer to the second voltage level conversion unit 140 for converting a voltage level used in the communication speed converter 130.

In addition, an ECU connector 110 for connecting the communication interface 100 and the electronic control unit (ECU) 200 is connected to the first voltage level converting unit 120, and the second voltage level converting unit ( On the side of 140, a terminal connector 150 for connecting the communication interface 100 and the computer 300 is connected.

In order for the electronic control unit (ECU) 200 and the general computer 300 to communicate directly, there must be a communication means that enables the exchange of information therebetween. However, as described above, the electronic control unit (ECU) 200 exchanges information with external devices using communication protocols such as ISO9141, SAE J1850, CAN, and the computer 300 uses RS232 serial communication for information. In order to exchange information by directly connecting them, an interface for converting a communication speed and a voltage level used in one device into a communication speed and a voltage level used in another device is needed.

For example, in the case of the ISO9141 communication protocol used in the electronic control unit (ECU) 200, the communication speed is 10.4KHz, and 0V is defined as low level and 12V is defined as high level. On the other hand, in the case of RS232 serial communication used in the general computer 300, the communication speed is 9600 Hz, and since + 10V is defined as low level and -10V is defined as high level, the electronic control unit (ECU) 200 If you want to use the data stored in the computer 300, the communication speed and voltage level used in the electronic control unit (ECU) 200 protocol is the communication speed and voltage level of RS232 serial communication of the computer 300. In the case of sending a command requesting data retrieval from the computer 300 to the electronic control unit (ECU) 200, the control speed and voltage level of the RS232 serial communication of the computer 300 are controlled electronically. Unit ( By using a communication interface that converts the communication speed and voltage level used in the communication protocol of the ECU (200), it is possible to enable information exchange between them.

Among the communication protocols of the electronic control unit (ECU) 200, for example, ISO9141 specifies a communication speed of 10.4 KHz for communication with an external modem, but a communication speed of serial communication such as RS232 supported in a general computer 300 is It only provides regular speeds such as 9600Hz and does not support non-standard speeds such as 10.4KHz. In the present invention, the communication speed problem is solved by configuring the communication speed conversion unit 130 as a one chip microcomputer for communication speed conversion such as PIC16C05 or PIC16F84.

One-chip microcomputer constituting the communication speed conversion unit 130 is a device for converting the communication speed of the electronic control unit (ECU) 200 and the computer 300 connected to both ends of the communication interface 100, For example, if you want to communicate with the RS232 serial communication of the computer 300 by the ISO9141 communication protocol of the electronic control unit (ECU) 200, convert the communication speed of 10.4KHz of the ISO9141 communication protocol to the communication speed 9600Hz suitable for RS232 serial communication or On the contrary, it converts the communication speed 9600Hz of RS232 serial communication into the communication speed 10.4KHz of ISO9141 communication protocol.

In addition, in the present invention, in order to solve the communication failure problem caused by the difference in the voltage level of the communication protocol such as ISO9141 of the electronic control unit (ECU) 200 and the serial communication such as RS232 of the computer 300, A first voltage level converter 120 and a second voltage level converter 140 are provided at the front and the rear of the communication speed converter 130, respectively, so that the voltage level of the ISO9141 communication protocol is changed to the voltage level of RS232 serial communication. Or converts the voltage level of RS232 serial communication to the voltage level of ISO9141 communication protocol.

That is, when information is transmitted from the electronic control unit (ECU) 200 to the computer 300, the first voltage level converting unit 120 uses the one chip constituting the communication speed converting unit 130 to set the voltage level of ISO9141. Convert the voltage level of the microcomputer to the voltage level of the microcomputer, and convert the voltage level of the one-chip microcomputer to the voltage level of RS232 to convert the voltage level of the ISO9141 into a voltage level suitable for the RS232 serial communication. On the contrary, when a command is transmitted from the computer 300 to the electronic control unit (ECU) 200, the second voltage level converting unit 140 configures the communication speed converting unit 130 to convert the voltage level of RS232. Converts the voltage level of the one-chip microcomputer to a voltage level of ISO9141 by converting the voltage level of the one-chip microcomputer into a voltage level of ISO9141. Convert to a voltage level suitable for 1.

At this time, in the present invention, the first voltage level converter 120 configures a circuit using, for example, a plurality of transistors and resistors, and the second voltage level converter 140 uses, for example, a MAX232 IC (Intergrated Circuit). Configure using Accordingly, the voltage level defined in the communication protocol of the electronic control unit (ECU) 200 such as ISO9141, that is, the 0V low level and the 12V high level passes through the first voltage level converting unit 120 and primarily communicates with the communication speed converting unit. After the voltage level of 130, i.e., 0V low level and 5V high level is converted, it is then passed through the second voltage level converting unit 140 and finally, the voltage level of serial communication such as RS232 of the computer, that is, + 10V low Level, -10V high level, and vice versa, the voltage level is converted through the second voltage level converter 140 and the first voltage level converter 120 in order.

Hereinafter, a method of outputting data on the vehicle state recorded in the electronic control unit (ECU) 200 of the vehicle using the communication interface 100 according to the present invention to the computer 300 will be described.

The ECU connector 110 of the communication interface 100 is connected to an electronic control unit (ECU) 200 of a vehicle, and the terminal connector 150 is connected to a terminal of a computer 300 such as a PC, a notebook, a PDA, and the like. When the power is supplied to the communication interface 100, the communication interface 100 is in an initialization state in which communication with the computer is possible.

Subsequently, when a command for requesting data regarding a state of a vehicle is received from the computer 300 on the communication interface 100 through the terminal connector 150, the command passes through the second voltage level converter 140. After the voltage level is first converted, the communication speed converter 130 adds a message head of 3 bytes to the command and adds a check sum for error verification purposes at the end of the data frame, After converting to suit the communication protocol used in the control unit (ECU), and then converted to a voltage level suitable for the communication protocol used in the electronic control unit (ECU) through the first voltage level converting unit 120, the ECU It is transmitted to the electronic control unit (ECU) 200 of the motor vehicle via the connector 110.

By a command received by the electronic control unit (ECU) 200, a data frame relating to a vehicle state stored in a memory of the electronic control unit (ECU) is received by the communication interface 100 through the ECU connector 110. When the data frame is first converted through the first voltage level converter 120 and the voltage level is converted, the data frame is passed through the communication speed converter 130 and the message head and checksum of 3 bytes in the data frame. ), Leaving only the data bytes and at the same time the communication speed is converted to be suitable for serial communication, such as RS232 of the computer 300, followed by a second voltage level conversion unit 140, the voltage level suitable for serial communication of the computer And then sent to the computer 300 via the terminal connector 150.

Therefore, the user can read the data displayed through the computer 300 screen and find out the state of the car.

If it is possible to directly connect and communicate with the automatic control unit (ECU) 200 of the vehicle and the computer 300, the general state of the vehicle, for example, unlike the general troubleshooting apparatus that could only read the troubleshooting code of the differential vehicle. The cooling water temperature, the RPM RPM, etc. can be known in detail, so that the instructions for the maintenance can be accurately corrected. In the case of a general troubleshooting device, the maintenance guide, the electric wiring diagram, etc. could not be mounted due to insufficient memory capacity. In this case, creating a PC-based scan tool through a communication interface solves this problem and, in combination with the Internet network, can provide a platform for remote maintenance.

In addition, since the communication interface according to the present invention establishes a communication interface using a one-chip microcomputer, the manufacturing cost is low, and a user-oriented failure is possible because the user can frequently diagnose the failure and condition of the vehicle at the price of one communication interface. You can run a check.

In FIG. 2, the communication protocol used in the electronic control unit (ECU) is described as ISO9141, and the serial communication supported by the computer is described as RS232. However, communication between the electronic control unit (ECU) and the computer is possible. In order to configure the two voltage level conversion unit to convert the voltage level and the communication interface including the technical idea of the present invention to convert the communication speed through the communication speed conversion unit consisting of a one-chip microcomputer, It goes without saying that the technical scope is not limited by the type of computer serial communication.

3 is a block diagram of a vehicle state display device having a communication interface according to the present invention.

In a vehicle with a long driving time such as a taxi or a truck for transportation, the failure of the vehicle while driving is fatal in terms of work efficiency and economics. Therefore, if the vehicle is equipped with a device for displaying the condition of the vehicle from time to time, the driver can determine the condition of the vehicle through this device from time to time, and accordingly, the vehicle can be checked and operated in advance so that a sudden breakdown occurs while driving. Can be reduced.

Differential vehicle status display device 400 with a communication interface according to the present invention, for the purpose as mentioned, the communication interface 410 connected to the electronic control unit (ECU) 200 of the vehicle, and the communication interface And a liquid crystal display 420 connected to the 410 and integrally provided therewith.

The communication interface 410 is configured as described with reference to FIG. 2 in order to enable the electronic control unit (ECU) 200 to communicate with the external device, and the liquid crystal display device 420 is an electronic control unit. When the data read out from the memory of the ECU 200 is received through the communication interface 410, the data is displayed on a screen so that the vehicle state can be checked at any time.

In this case, the liquid crystal display 420 does not display the state of the vehicle only by a diagnostic code, but displays the state of each part, such as the coolant temperature and the RPM, in detail, so that the user can easily grasp the state of the vehicle. . In addition, the liquid crystal display 420 is preferably attached to a suitable place in the vehicle so as to easily attract the attention of the driver, the communication interface 410 is connected to the electronic control unit (ECU) 200.

According to the communication interface using the one-chip microcomputer according to the present invention, it is possible to directly communicate with the automatic control unit (ECU) of the vehicle and the computer, so that the overall state of the vehicle, for example, the coolant temperature, the RPM RPM, etc. can be known in detail. So that the instructions for maintenance can be accurate.

In addition, a computer equipped with a maintenance guide, an electric wiring diagram, and the like can be used to make a PC based scan tool, and can be combined with an internet network to provide a platform for remote maintenance.

In addition, since the communication interface according to the present invention establishes a communication interface using a one-chip microcomputer, its manufacturing cost is low, and a user-oriented failure is possible because the user can frequently diagnose the failure and condition of the vehicle at the price of one communication interface. You can run a check.

On the other hand, according to the vehicle status display device having a communication interface according to the present invention, since the driver can check the state of the vehicle at any time through the liquid crystal display device, vehicle inspection can be performed in advance, thereby reducing the occurrence of sudden failure during driving. .

1 is a schematic diagram showing a general vehicle inspection system.

2 is a block diagram of a communication interface using a one-chip microcomputer according to the present invention.

3 is a block diagram of a vehicle state display device having a communication interface according to the present invention.

* Description of the symbols for the main parts of the drawings *

100, 410: communication interface 110: ECU connector

120: first voltage level converter 130: communication speed converter

140: second voltage level converter 150: terminal connector

200: Electronic control unit (ECU) 300: Computer

400: vehicle status display device 420: liquid crystal display device

Claims (7)

An ECU connector for connecting a communication interface with an electronic control unit (ECU); One end is connected to the ECU connector and the other end is connected to a communication speed converter to convert the voltage level of the communication protocol used in the electronic control unit (ECU) to the voltage level used in the communication speed converter, or vice versa. A first voltage level converting unit converting a voltage level used in the communication speed converting unit into a voltage level of a communication protocol used in the electronic control unit (ECU); One end is connected to the first voltage level converter and the other end is connected to the second voltage level converter to convert the communication speed of the communication protocol used in the electronic control unit (ECU) into the communication speed of general computer serial communication. Or, conversely, changing a communication speed of general computer serial communication to a communication speed of a communication protocol used in the electronic control unit (ECU); One end is connected to the communication speed converter and the other end is connected to the terminal connector to convert the voltage level used in the communication speed converter to a voltage level of general computer serial communication, or vice versa. A second voltage level converting unit converting the voltage level used in the communication speed converting unit; And And a terminal connector connected to the second voltage level converter and configured to connect a communication interface with a computer. The method of claim 1, The communication speed converter is a communication interface using a one-chip microcomputer, characterized in that consisting of a one-chip microcomputer. The method of claim 2, The one-chip microcomputer is a communication interface using a one-chip microcomputer, characterized in that the PIC16C06 or PIC16F84. The method of claim 1, And the first voltage level converter is a circuit composed of a plurality of transistors and resistors, and the second voltage level converter is configured by a MAX 232 IC. The method of claim 4, wherein The communication protocol used in the electronic control unit (ECU) is ISO9141, and the serial communication supported by the computer is RS232. A communication interface that enables communication between the electronic control unit and an external device; And a liquid crystal display device which is integrally connected with the communication interface and displays a state of the vehicle. The method of claim 6, The communication interface includes a first voltage level converter, a communication speed converter, and a second voltage level converter.