CN118112362A - Automobile cable fault diagnosis method and system - Google Patents

Abstract

The invention relates to the technical field of cable fault diagnosis, in particular to an automobile cable fault diagnosis method and system. When a cable fault diagnosis instruction is received, an excitation signal is output to a cable to be detected, and timing is started; stopping timing when receiving an excitation signal reflected by a cable fault point; the position of the fault point of the cable to be detected is judged based on the transmission speed and the timing duration of the excitation signal, so that compared with a traditional multimeter method, the time and labor intensity required by fault diagnosis can be obviously reduced, the maintenance efficiency is improved, and the fault position of the cable is accurately diagnosed.

Description

Automobile cable fault diagnosis method and system

Technical Field

The invention relates to the technical field of cable fault diagnosis, in particular to an automobile cable fault diagnosis method and system.

Background

Multimeters are a traditional tool used by automotive service personnel to diagnose electrical wiring problems. A basic multimeter can measure voltage, current, and resistance and can therefore be used to detect whether a cable has an open or shorted problem. For example, by measuring the resistance across a cable, if the reading is infinite, it can be initially determined that an open circuit exists in the cable; if the reading is abnormally low, a cable short circuit may be indicated.

However, conventional multimeter detection methods have some limitations. When it is determined that the cable is open, the multimeter can only tell us that the cable is "entirely" out of communication, but cannot accurately indicate the location of the disconnection.

The foregoing is provided merely for the purpose of facilitating understanding of the technical solutions of the present invention and is not intended to represent an admission that the foregoing is prior art.

Disclosure of Invention

The invention mainly aims to provide a method and a system for diagnosing automobile cable faults, and aims to solve the technical problem that a method for checking automobile cable faults by using a universal meter cannot judge a specific disconnection position point of a cable to be tested in the prior art.

In order to achieve the above object, the present invention provides a method for diagnosing a fault of an automotive cable, the method comprising the steps of:

when a cable fault diagnosis instruction is received, outputting an excitation signal to a cable to be detected and starting timing;

stopping timing when receiving an excitation signal reflected by a cable fault point;

and judging the position of the fault point of the cable to be detected based on the transmission speed and the timing duration of the excitation signal.

Optionally, the determining the position of the fault point of the cable to be detected based on the transmission speed and the timing duration of the excitation signal includes:

determining the distance from the fault point to the excitation signal output point based on the transmission speed and the timing duration of the excitation signal;

And judging the position of the fault point of the cable to be detected according to the distance from the fault point to the excitation signal output point.

Optionally, when receiving the cable fault diagnosis instruction, outputting an excitation signal to the cable to be detected and starting timing, including:

when a cable fault diagnosis instruction is received, a fault diagnosis circuit is communicated through a signal selection switch;

And outputting an excitation signal to a cable to be detected based on the fault diagnosis circuit and starting timing.

Optionally, the method further comprises:

when a normal data communication instruction is received, a normal data communication line is communicated through a signal selection switch;

And carrying out data communication based on the normal data communication line.

Optionally, after the determining the position of the fault point of the cable to be detected based on the transmission speed and the timing duration of the excitation signal, the method further includes:

and reporting the fault point position to an upper computer through a CAN communication module.

In addition, to achieve the above object, the present invention also provides an automobile cable fault diagnosis system, the system comprising: the system comprises a signal sending module, a signal receiving module and a fault judging module;

The fault judging module is respectively connected with the signal sending module and the signal receiving module, and the signal sending module and the signal receiving module are connected with a cable to be detected;

The signal sending module is used for outputting an excitation signal to the cable to be detected and starting timing when receiving a cable fault diagnosis instruction;

The signal receiving module stops timing when receiving an excitation signal reflected by a cable fault point;

The fault judging module is used for judging the position of the fault point of the cable to be detected based on the transmission speed and the timing duration of the excitation signal.

Optionally, the fault judging module is specifically configured to determine a distance from a fault point to the excitation signal output point based on the transmission speed and the timing duration of the excitation signal, and judge the position of the fault point of the cable to be detected according to the distance from the fault point to the excitation signal output point.

Optionally, the signal sending module is specifically configured to, when receiving a cable fault diagnosis instruction, communicate a fault diagnosis line through a signal selection switch, output an excitation signal to a cable to be detected based on the fault diagnosis line, and start timing.

Optionally, the system further comprises: a signal selection module;

the signal selection module is connected with the signal transmission module;

and the signal selection module is used for communicating the normal data communication line through the signal selection switch when receiving the normal data communication instruction and carrying out data communication based on the normal data communication line.

Optionally, the system further comprises: a fault reporting module;

The fault reporting module is connected with the fault judging module;

the fault reporting module is used for reporting the fault point position to the upper computer through the CAN communication module.

When a cable fault diagnosis instruction is received, an excitation signal is output to a cable to be detected, and timing is started; stopping timing when receiving an excitation signal reflected by a cable fault point; and judging the position of the fault point of the cable to be detected based on the transmission speed and the timing time length of the excitation signal, so that compared with the traditional multimeter method, the time and labor intensity required by fault diagnosis can be obviously reduced, the maintenance efficiency is improved, and the fault position of the cable can be accurately diagnosed.

Drawings

FIG. 1 is a schematic flow chart of a first embodiment of an automotive cable fault diagnosis method according to the present invention;

FIG. 2 is a flowchart of a second embodiment of the method for diagnosing a cable fault of an automobile according to the present invention;

FIG. 3 is a schematic functional block diagram of a first embodiment and a second embodiment of an automotive cable fault diagnosis system according to the present invention;

FIG. 4 is a schematic diagram of an automotive cable fault diagnosis system according to the present invention;

Fig. 5 is a schematic explanatory diagram of a fault diagnosis module of the automotive cable fault diagnosis system of the present invention.

The achievement of the objects, functional features and advantages of the present invention will be further described with reference to the accompanying drawings, in conjunction with the embodiments.

Detailed Description

It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.

Referring to fig. 1, a first embodiment of an automotive cable fault diagnosis method of the present invention provides an automotive cable fault diagnosis method, the method comprising:

s10: when a cable fault diagnosis instruction is received, outputting an excitation signal to a cable to be detected and starting timing;

S20: stopping timing when receiving an excitation signal reflected by a cable fault point;

S30: and judging the position of the fault point of the cable to be detected based on the transmission speed and the timing duration of the excitation signal.

It should be noted that, the execution body of the embodiment may be a computing service device with functions of data processing, network communication and program running, such as a tablet computer, a personal computer, a mobile phone, or other electronic devices capable of implementing the above functions.

It will be appreciated that when an excitation signal (typically an electrical pulse) is transmitted on a fault-free conductor, it will reach the conductor end point without reflection. If there is a fault point, such as an open circuit or a short circuit, on the conductor, the excitation signal will reflect when it encounters the fault point. By measuring the time difference between the emission and return of the excitation signal, the location of the fault point can be located, since the propagation speed of the electromagnetic wave on the conductor is known.

In particular implementations, after receiving instructions for cable fault diagnosis, the test device sends an electrical pulse or other form of excitation signal to the cable to be tested. And simultaneously starting to time and recording the starting time of the excitation signal transmission. Waiting for and capturing the excitation signal reflected back from the fault point can be done by monitoring the cable at both ends or specific detection points. Once the reflected signal is detected, the timer is stopped immediately and the point in time at which the reflected signal returns is recorded. The location of the fault point is calculated from the known propagation velocity of the electrical pulse within the cable and the recorded time difference. The formula is generally: fault point location= (signal speed time difference)/2. The division by 2 is because the time difference includes the total time period for the excitation signal to reach the fault point and to return from the fault point.

For easy understanding, referring to fig. 5, fig. 5 is a schematic diagram of a fault diagnosis module of the automotive cable fault diagnosis system according to the present invention, wherein the fault diagnosis module mainly comprises a signal transmitting unit, a signal receiving unit and a controller, and the main diagnosis principle process is as follows:

d.1, the controller controls the signal transmitting unit to transmit a square wave signal as an excitation signal at the time t 0;

d.2, enabling the excitation signal to reach the signal receiving unit through the path e- > i- > g at the time t1, and starting a timer for timing after the controller monitors the excitation signal received by the signal receiving unit;

d.3, after being sent out from T0, the excitation signal reaches the signal receiving unit through e- > i- > g, and also reaches the cable breakpoint through e- > i- > f at the same time and generates reflection (the impedance at the cable breakpoint is suddenly changed, the excitation signal is reflected here), the reflected signal reaches the signal receiving unit through f- > i- > g process, the controller stops the timing of the d.2 timer after monitoring the reflected signal received by the signal receiving unit, and the time counted by the d.2-d.3 process timer is taken as T;

d.4, the transmission speed of the electric signal in the specific medium cable is fixed, and the speed can be calculated as V;

And d.5, based on the process, the path e- > i- > g is very short and can be ignored. The cable break-point-to-fault diagnosis unit can thus be approximated as h=v×t/2.

In the embodiment, when a cable fault diagnosis instruction is received, an excitation signal is output to a cable to be detected, and timing is started; stopping timing when receiving an excitation signal reflected by a cable fault point; and judging the position of the fault point of the cable to be detected based on the transmission speed and the timing time length of the excitation signal, so that compared with the traditional multimeter method, the time and labor intensity required by fault diagnosis can be obviously reduced, the maintenance efficiency is improved, and the fault position of the cable can be accurately diagnosed.

Referring to fig. 2, fig. 2 is a schematic flow chart of a second embodiment of the automotive cable fault diagnosis method according to the present invention, and based on the embodiment shown in fig. 1, the second embodiment of the automotive cable fault diagnosis method according to the present invention is proposed.

In the second embodiment, step S30 includes:

s301: determining the distance from the fault point to the excitation signal output point based on the transmission speed and the timing duration of the excitation signal;

S302: and judging the position of the fault point of the cable to be detected according to the distance from the fault point to the excitation signal output point.

The step S10 includes:

s101: when a cable fault diagnosis instruction is received, a fault diagnosis circuit is communicated through a signal selection switch;

S102: and outputting an excitation signal to a cable to be detected based on the fault diagnosis circuit and starting timing.

It should be noted that, when the fault diagnosis apparatus receives an external fault diagnosis instruction (such as issued by a manual operator or diagnosis software), the system starts the fault detection process of the cable. A signal selection switch within the device, which electrically connects the fault diagnosis device to the cable to be tested, will respond to this diagnosis command. The function of the signal selection switch is to ensure that the excitation signal is sent only to the specific cable to be detected without affecting other circuits or cables within the car. This may be an actual physical relay or a solid state switch.

It should be understood that, in the present embodiment, when a normal data communication instruction is received, the normal data communication line is connected through the signal selection switch; and carrying out data communication based on the normal data communication line.

Further, in the present embodiment, after step S30, the method further includes:

step S40: and reporting the fault point position to an upper computer through a CAN communication module.

It should be noted that, the communication module for reporting the fault may be a vehicle-mounted CAN communication module, or may be a unit module based on protocols such as FPD-Link, GMSL, etc. that may be implemented to connect to an upper computer of the device a/B and upload fault information.

Referring to fig. 3, a first embodiment of an automotive cable fault diagnosis system of the present invention provides an automotive cable fault diagnosis system, the system comprising:

Signal transmission module 10: when a cable fault diagnosis instruction is received, an excitation signal is output to a cable to be detected, and timing is started;

signal receiving module 20: the device is used for stopping timing when receiving an excitation signal reflected by a cable fault point;

Fault determination module 30: and the position of the fault point of the cable to be detected is judged based on the transmission speed and the timing duration of the excitation signal.

It should be noted that, the execution body of the embodiment may be a computing service device with functions of data processing, network communication and program running, such as a tablet computer, a personal computer, a mobile phone, or other electronic devices capable of implementing the above functions.

It will be appreciated that when an excitation signal (typically an electrical pulse) is transmitted on a fault-free conductor, it will reach the conductor end point without reflection. If there is a fault point, such as an open circuit or a short circuit, on the conductor, the excitation signal will reflect when it encounters the fault point. By measuring the time difference between the emission and return of the excitation signal, the location of the fault point can be located, since the propagation speed of the electromagnetic wave on the conductor is known.

In particular implementations, after receiving instructions for cable fault diagnosis, the test device sends an electrical pulse or other form of excitation signal to the cable to be tested. And simultaneously starting to time and recording the starting time of the excitation signal transmission. Waiting for and capturing the excitation signal reflected back from the fault point can be done by monitoring the cable at both ends or specific detection points. Once the reflected signal is detected, the timer is stopped immediately and the point in time at which the reflected signal returns is recorded. The location of the fault point is calculated from the known propagation velocity of the electrical pulse within the cable and the recorded time difference. The formula is generally: fault point location= (signal speed time difference)/2. The division by 2 is because the time difference includes the total time period for the excitation signal to reach the fault point and to return from the fault point.

For easy understanding, referring to fig. 5, fig. 5 is a schematic diagram of a fault diagnosis module of the automotive cable fault diagnosis system according to the present invention, wherein the fault diagnosis module mainly comprises a signal transmitting unit, a signal receiving unit and a controller, and the main diagnosis principle process is as follows:

d.1, the controller controls the signal transmitting unit to transmit a square wave signal as an excitation signal at the time t 0;

d.2, enabling the excitation signal to reach the signal receiving unit through the path e- > i- > g at the time t1, and starting a timer for timing after the controller monitors the excitation signal received by the signal receiving unit;

d.3, after being sent out from T0, the excitation signal reaches the signal receiving unit through e- > i- > g, and also reaches the cable breakpoint through e- > i- > f at the same time and generates reflection (the impedance at the cable breakpoint is suddenly changed, the excitation signal is reflected here), the reflected signal reaches the signal receiving unit through f- > i- > g process, the controller stops the timing of the d.2 timer after monitoring the reflected signal received by the signal receiving unit, and the time counted by the d.2-d.3 process timer is taken as T;

d.4, the transmission speed of the electric signal in the specific medium cable is fixed, and the speed can be calculated as V;

And d.5, based on the process, the path e- > i- > g is very short and can be ignored. The cable break-point-to-fault diagnosis unit can thus be approximated as h=v×t/2.

In the embodiment, when a cable fault diagnosis instruction is received, an excitation signal is output to a cable to be detected, and timing is started; stopping timing when receiving an excitation signal reflected by a cable fault point; and judging the position of the fault point of the cable to be detected based on the transmission speed and the timing time length of the excitation signal, so that compared with a traditional multimeter system, the time and labor intensity required by fault diagnosis can be obviously reduced, the maintenance efficiency is improved, and the fault position of the cable can be accurately diagnosed.

Referring to fig. 3, fig. 3 is a schematic diagram of a second embodiment of the automotive cable fault diagnosis system of the present invention.

In the second embodiment, the fault determining module 30 is specifically configured to determine a distance from a fault point to the excitation signal output point based on the transmission speed and the timing duration of the excitation signal, and determine the position of the fault point of the cable to be detected according to the distance from the fault point to the excitation signal output point.

The signal sending module 10 is specifically configured to, when receiving a cable fault diagnosis instruction, communicate a fault diagnosis line through a signal selection switch, output an excitation signal to a cable to be detected based on the fault diagnosis line, and start timing.

It should be noted that, when the fault diagnosis apparatus receives an external fault diagnosis instruction (such as issued by a manual operator or diagnosis software), the system starts the fault detection process of the cable. A signal selection switch within the device, which electrically connects the fault diagnosis device to the cable to be tested, will respond to this diagnosis command. The function of the signal selection switch is to ensure that the excitation signal is sent only to the specific cable to be detected without affecting other circuits or cables within the car. This may be an actual physical relay or a solid state switch.

It should be understood that in this embodiment, the system further includes: a signal selection module 00;

the signal selection module 00 is connected with the signal transmission module;

The signal selection module 00 is configured to, when receiving a normal data communication instruction, communicate a normal data communication line through a signal selection switch, and perform data communication based on the normal data communication line.

Further, in the present embodiment, after step S30, the method further includes: a failure reporting module 40;

The fault reporting module 40 is connected with the fault judging module 30;

The fault reporting module 40 is configured to report the fault point position to an upper computer through a CAN communication module.

It should be noted that, the communication module for reporting the fault may be a vehicle-mounted CAN communication module, or may be a unit module based on protocols such as FPD-Link, GMSL, etc. that may be implemented to connect to an upper computer of the device a/B and upload fault information.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or system. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or system that comprises the element.

The foregoing embodiment numbers of the present invention are merely for the purpose of description, and do not represent the advantages or disadvantages of the embodiments.

From the above description of the embodiments, it will be clear to those skilled in the art that the above-described embodiment method may be implemented by means of software plus a necessary general hardware platform, but of course may also be implemented by means of hardware, but in many cases the former is a preferred embodiment. Based on such understanding, the technical solution of the present invention may be embodied essentially or in a part contributing to the prior art in the form of a software product stored in a storage medium (e.g. ROM/RAM, magnetic disk, optical disk) comprising instructions for causing a terminal device (which may be a mobile phone, a computer, a server, an air conditioner, or a network device, etc.) to perform the method according to the embodiments of the present invention.

The foregoing description of the invention and the accompanying drawings is only illustrative, and is not intended to limit the scope of the invention, but rather is to be construed in any way in view of the following description, the accompanying drawings and the like.

Claims (10)

1. A method for diagnosing a cable fault of an automobile, the method comprising:

when a cable fault diagnosis instruction is received, outputting an excitation signal to a cable to be detected and starting timing;

stopping timing when receiving an excitation signal reflected by a cable fault point;

and judging the position of the fault point of the cable to be detected based on the transmission speed and the timing duration of the excitation signal.

2. The automobile cable fault diagnosis method according to claim 1, wherein the judging the position of the to-be-detected cable fault point based on the transmission speed and the time duration of the excitation signal includes:

determining the distance from the fault point to the excitation signal output point based on the transmission speed and the timing duration of the excitation signal;

And judging the position of the fault point of the cable to be detected according to the distance from the fault point to the excitation signal output point.

3. The method for diagnosing a cable fault of an automobile as claimed in claim 1, wherein said outputting an excitation signal to the cable to be tested and starting timing upon receiving a cable fault diagnosis instruction comprises:

when a cable fault diagnosis instruction is received, a fault diagnosis circuit is communicated through a signal selection switch;

And outputting an excitation signal to a cable to be detected based on the fault diagnosis circuit and starting timing.

4. The automotive cable fault diagnosis method of claim 3, further comprising:

when a normal data communication instruction is received, a normal data communication line is communicated through a signal selection switch;

And carrying out data communication based on the normal data communication line.

5. The method for diagnosing an automotive cable fault according to claim 1, further comprising, after said determining the position of the cable fault point to be detected based on the transmission speed and the time duration of the excitation signal:

and reporting the fault point position to an upper computer through a CAN communication module.

6. An automotive cable fault diagnosis system, the system comprising: the system comprises a signal sending module, a signal receiving module and a fault judging module;

The fault judging module is respectively connected with the signal sending module and the signal receiving module, and the signal sending module and the signal receiving module are connected with a cable to be detected;

The signal sending module is used for outputting an excitation signal to the cable to be detected and starting timing when receiving a cable fault diagnosis instruction;

The signal receiving module stops timing when receiving an excitation signal reflected by a cable fault point;

The fault judging module is used for judging the position of the fault point of the cable to be detected based on the transmission speed and the timing duration of the excitation signal.

7. The system for diagnosing a cable fault of an automobile as claimed in claim 6, wherein said fault judging module is specifically configured to determine a distance from a fault point to said excitation signal output point based on a transmission speed and a timing duration of said excitation signal, and judge a position of said fault point of said cable to be detected based on said distance from said fault point to said excitation signal output point.

8. The system for diagnosing a cable fault of an automobile according to claim 6, wherein the signal transmitting module is specifically configured to communicate a fault diagnosis line through the signal selection switch when a cable fault diagnosis command is received, output an excitation signal to a cable to be detected based on the fault diagnosis line, and start timing.

9. The automotive cable fault diagnosis system of claim 8 wherein the system further comprises: a signal selection module;

the signal selection module is connected with the signal transmission module;

and the signal selection module is used for communicating the normal data communication line through the signal selection switch when receiving the normal data communication instruction and carrying out data communication based on the normal data communication line.

10. The automotive cable fault diagnosis system of claim 6 wherein the system further comprises: a fault reporting module;

The fault reporting module is connected with the fault judging module;

the fault reporting module is used for reporting the fault point position to the upper computer through the CAN communication module.