CN211149435U - Adapter for vehicle-mounted diagnosis system - Google Patents

Abstract

The utility model discloses an adapter for on-vehicle diagnostic system, it includes isolation protection unit, first and second conversion unit, isolation protection unit communication is connected between vehicle diagnosis interface and first conversion unit and the configuration carries out electrical isolation to the K-line communication signal of vehicle diagnosis interface, first conversion unit communication is connected between isolation protection unit and second conversion unit and is configured to carry out the conversion between K-line communication signal and TT L communication signal, second conversion unit communication is connected between first conversion unit and host computer interface and is configured to carry out the conversion between TT L communication signal and the USB communication signal.

Description

Adapter for vehicle-mounted diagnosis system

Technical Field

The utility model relates to an on-vehicle diagnostic system field, more specifically, the utility model relates to an adapter for on-vehicle diagnostic system.

Background

An On-Board Diagnostic (OBD) is a detection system extended for vehicle fault diagnosis, which can monitor the operation conditions of a plurality of systems and components On a vehicle in real time, including an engine, an emission control system, an oil supply system, and the like.

The K-line protocol has long been widely used in diagnostic procedures for various vehicle types. The K-line protocol is a standard diagnostic protocol following ISO 14230 and is based on typical UART circuitry as is the serial standard interface technology RS 232. In the asynchronous transmission process based on the K-line protocol, the start-stop bit is used for synchronizing the transmitter and the receiver, so that the diagnosis system does not need to be provided with an additional clock line and can be suitable for a unidirectional line.

The physical layer voltage of the diagnostic interface of the physical electrical layer (also called as 'K-L ine' in the trade term) based on the KWP2000 protocol is 12V for passenger vehicles, while 24 V.K-L ine for commercial vehicles is similar to a data bus system, and can communicate with various control devices through addressing, and the communication connection between the conventional K-L ine diagnostic system and an upper computer is realized by converting a serial port (such as an RS-232 standard serial port) into a K-L ine mode.

With the trend of lighter and lighter PC terminals, many portable computer terminals do not have RS-232 serial ports, so that communication cannot be performed in the actual diagnosis process. At present, many light-weight computers adopt a communication mode of a USB interface, and compared with the data transmission rate of an RS-232 bus, the transmission rate of the USB is higher.

However, if a simple USB-to-serial communication method is adopted between the vehicle and the upper computer terminal, the instantaneous voltage will change dramatically due to the power fluctuation during the vehicle diagnosis process, resulting in the interference of the diagnosis signal, and thus an effective and reliable diagnosis communication cannot be established, which may lead to the burning of the USB interface, or even the damage of the upper computer. This is a major technical problem to be solved urgently in the industry at present.

SUMMERY OF THE UTILITY MODEL

In order to solve the above-mentioned problem among the prior art, the utility model relates to an adapter for on-vehicle diagnostic system, it has increased the electrical isolation to the K-line signal of vehicle diagnosis interface end on realizing K-line commentaries on classics TT L serial ports's basis to TT L serial ports commentaries on classics USB function has been increased, makes all portable computers that have the USB interface all can be connected to K-line in order to carry out failure diagnosis, the utility model discloses an isolation protection device can match the K-line signal based on different vehicle voltage standards to can completely cut off interference, the impact that vehicle voltage changes and lead to in the twinkling of an eye, ensure still reliable communication under the adverse conditions, protect computer USB interface to avoid damaging.

The utility model provides an adapter for on-vehicle diagnostic system, the adapter is configured to carry out the communication between vehicle diagnosis interface and the host computer interface and is connected, the adapter includes isolation protection unit, first communication signal conversion unit and second communication signal conversion unit, wherein, isolation protection unit communication connection is in between vehicle diagnosis interface and the first communication signal conversion unit, and the configuration carries out electrical isolation to the K-line communication signal of vehicle diagnosis interface, first communication signal conversion unit communication connection is in between isolation protection unit and the second communication signal conversion unit, and the configuration carries out the conversion between K-line communication signal and TT L communication signal, second communication signal conversion unit communication connection is in between first communication signal conversion unit and the host computer interface, and the configuration carries out the conversion between TT L communication signal and the USB communication signal.

According to a preferred example, the isolation protection unit electrically adopts a PC817 optical coupling isolation chip.

According to a preferred example, the vehicle diagnostic interface is a K-line serial interface.

According to a preferred example, the upper computer interface is a USB interface.

According to a preferred example, the USB interface employs an a-type plug.

According to a preferred example, the first communication signal conversion unit adopts an MC33199 chip.

According to a preferred example, the second communication signal conversion unit employs a P L2303 HXD chip.

The utility model discloses the beneficial effect that can realize lies in, has realized the electrical isolation between vehicle and the diagnosis host computer (for example, the computer), can match between different K-line signal voltage and the TT L voltage to strengthen the communication interference killing feature among the diagnostic process, protected the computer end interface of diagnosis host computer.

Drawings

Other features and advantages of the system of the present invention will become apparent from or more particularly, the accompanying drawings, which are incorporated herein and which, together with the description, serve to explain certain principles of the invention. In the drawings:

FIG. 1 illustrates a block diagram of an adapter for an on-board diagnostic system according to an exemplary embodiment of the present invention;

fig. 2 shows a circuit diagram of an isolation protection unit according to an exemplary embodiment of the present invention;

FIG. 3 shows a circuit diagram of a K-line to TT L unit, according to an exemplary embodiment of the present invention, an

Fig. 4 shows a circuit diagram of TT L-to-USB unit according to an exemplary embodiment of the present invention.

Detailed Description

An adapter for an on-board diagnostic system according to the invention will be described below by way of example with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention to those skilled in the art. It will be apparent, however, to one skilled in the art that the present invention may be practiced without some of these specific details. Rather, any combination of the following features and elements, whether related to different embodiments or not, is contemplated to implement the present invention. Thus, the following aspects, features, embodiments and advantages are merely illustrative and should not be considered elements or limitations of the claims except where explicitly recited in a claim(s).

FIG. 1 illustrates a block diagram of an adapter for an on-board diagnostic system configured to perform a communication link between a vehicle diagnostic interface and an upper computer interface, according to an exemplary embodiment. The vehicle diagnosis interface is assumed to be a K-line serial interface, and the upper computer interface is a USB interface, especially a USB interface of an A-type plug.

As shown in FIG. 1, the adapter comprises an isolation protection unit, a K-line-to-TT L unit and a TT L-to-USB unit, wherein the isolation protection unit is in communication connection between a diagnosis interface at a vehicle end and the K-line-to-TT L unit and is configured to perform electrical isolation on K-line communication signals of the vehicle diagnosis interface, the K-line-to-TT L unit is in communication connection between the isolation protection unit and the TT L-to-USB unit and is configured to perform conversion between the K-line communication signals and TT L communication signals, and the TT L-to-USB unit is in communication connection between the K-line-to-TT L unit and an upper computer (for example, a computer terminal) interface and is configured to perform conversion between the TT L communication signals and USB communication signals.

For example, depending on the transmission direction of the target signal, the K-line to TT L unit may selectively convert a K-line signal from the vehicle into a TT L signal or convert a TT L signal into a K-line signal, and similarly, the TT L to USB unit may selectively convert a USB command from the host computer into a TT L signal or convert a TT L signal into a USB command.

When a diagnosis instruction is sent to a vehicle from an upper computer, the diagnosis upper computer is in communication connection with a diagnosis connection tool (namely, an adapter) through a USB interface, firstly, the communication speed of a K-line signal is set at the computer end of the upper computer, a corresponding diagnosis instruction is sent by means of an upper computer program, the K-line signal is converted into a TT L signal through a USB-to-TT L unit and is converted into a K-line signal through a TT L-to-K-line unit, and the K-line signal is finally transmitted to the vehicle diagnosis interface end through an isolation protection unit.

When the diagnosis information is fed back from the vehicle to the upper diagnosis computer, the K-line interface at the vehicle end sends the feedback information, the feedback information is transmitted to the K-line TT L conversion unit through the isolation protection unit to be converted into a TT L signal, the TT L USB conversion unit is used for converting the TT L signal into a USB command, and the USB command reaches the upper computer software program through the USB interface of the upper computer to be further processed or displayed.

Fig. 2 shows a circuit diagram of an isolation protection unit according to an exemplary embodiment of the present invention, wherein the isolation protection unit employs a PC817 opto-coupler isolation chip, which can isolate the electrical connection between the vehicle end and the upper computer end. The PC817 optical coupling isolation chip can be matched with K-line signals based on different vehicle voltage standards, can isolate interference and impact caused by vehicle voltage change in the moment, ensures reliable communication under severe conditions, and protects a USB interface of a computer from being damaged.

Fig. 3 shows a circuit diagram of a K-line to TT L unit according to an exemplary embodiment of the present invention, wherein the K-line to TT L unit employs an MC33199 chip for performing conversion between a K-line signal and a TT L signal.

Fig. 4 shows a circuit diagram of the TT L-to-USB unit according to an exemplary embodiment of the present invention, wherein the TT L-to-USB unit employs a P L2303 HXD chip, and the P L2303 HXD chip is used to realize the conversion between the serial port TT L communication of the single chip microcomputer and the USB communication of the computer.

In FIG. 4, the ports TT L _ TX and TT L _ RX in the P L2303 HXD chip (shown on the left side of FIG. 4) are respectively connected to the ports TXD and RXD in the MC33199 chip shown in FIG. 3, and the ports VBus, D-, D + and GND in the P L2303 HXD chip correspond to the USB interface on the computer side.

In conclusion, according to the utility model discloses an adapter, on the basis of realizing K-line commentaries on classics TT L serial ports, has increased the electrical isolation to the K-line signal of vehicle diagnosis interface end to TT L serial ports commentaries on classics USB function has been increased, makes all portable computers that have the USB interface all can be connected to K-line in order to carry out failure diagnosis.

Although the present invention has been described with reference to the preferred embodiments, the present invention is not limited thereto. Various changes and modifications can be made without departing from the spirit and scope of the present invention, and the scope of the present invention should be determined by the appended claims.

Claims (7)

1. An adapter for an on-board diagnostic system, the adapter being configured to perform a communication connection between a vehicle diagnostic interface and an upper computer interface, the adapter comprising an isolation protection unit, a first communication signal conversion unit and a second communication signal conversion unit,

the isolation protection unit is connected between the vehicle diagnosis interface and the first communication signal conversion unit in a communication mode and configured to perform electrical isolation on a K-line communication signal of the vehicle diagnosis interface;

the first communication signal conversion unit is connected between the isolation protection unit and the second communication signal conversion unit in a communication mode and is configured to convert a K-line communication signal and a TT L communication signal;

the second communication signal conversion unit is connected between the first communication signal conversion unit and the upper computer interface in a communication mode and is configured to perform conversion between TT L communication signals and USB communication signals.

2. The adapter as claimed in claim 1 wherein the isolation protection unit electrically employs a PC817 opto-coupled isolation chip.

3. The adapter of claim 1 or 2 wherein the vehicle diagnostic interface is a K-line serial interface.

4. The adapter of claim 1 or 2 wherein the host computer interface is a USB interface.

5. The adapter of claim 4 wherein the USB interface employs a type a plug.

6. The adapter as claimed in claim 1 or 2, wherein the first communication signal conversion unit employs a MC33199 chip.

7. The adapter as claimed in claim 1 or 2, wherein the second communication signal conversion unit is a P L2303 HXD chip.

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