CN112684371A

CN112684371A - Fault positioning method and diagnostic equipment of automobile bus and automobile detection system and method

Info

Publication number: CN112684371A
Application number: CN202011439507.9A
Authority: CN
Inventors: 王维林
Original assignee: Autel Intelligent Technology Corp Ltd
Current assignee: Autel Intelligent Technology Corp Ltd
Priority date: 2020-12-07
Filing date: 2020-12-07
Publication date: 2021-04-20
Anticipated expiration: 2040-12-07
Also published as: CN112684371B; WO2022121693A1

Abstract

The invention relates to the technical field of terminals, and discloses a fault positioning method, a diagnosis device, an automobile detection system and a method for an automobile bus, wherein the fault positioning method for the automobile bus comprises the following steps: acquiring a topological network among electronic control units in an automobile, wherein the electronic control units are connected through a bus; determining reference nodes in a topological network, wherein the reference nodes comprise a first reference node and/or a second reference node; determining a key node according to a reference node, wherein when the key node is in a disconnected state in a topological network, two network segments which are not communicated with each other exist in the topological network; and if a network section in the two network sections has a fault when one key node is disconnected, positioning the fault in the network section. By determining the key node and positioning the network section where the fault is located, the embodiment of the invention can improve the efficiency of positioning the fault of the automobile.

Description

Fault positioning method and diagnostic equipment of automobile bus and automobile detection system and method

Technical Field

The invention relates to the technical field of automobiles, in particular to a fault positioning method and a fault diagnosis device of an automobile bus, and an automobile detection system and method.

Background

A Controller Area Network (CAN) is one of the most widely used field buses in the world. The CAN bus protocol has become a standard bus for automotive computer control systems and embedded industrial control local area networks, and has a J1939 protocol which is designed for large trucks and heavy work machinery vehicles by taking CAN as an underlying protocol. In recent years, the high reliability and good error detection capability of the CAN bus protocol are emphasized, and the CAN bus protocol is widely applied to an automobile computer control system and an industrial environment with severe environmental temperature, strong electromagnetic radiation and large vibration. In the ECU communication of the automobile electronic parts, a CAN bus plays a very important role, particularly in a power assembly part, and the communication between ECUs is completed through a high-speed PT-CAN.

The high-speed CAN bus is a broadcast network, consists of two data buses CAN-H and CAN-L, and transmits differential signals, wherein, when any one data line is in fault, open circuit or short circuit, the whole network communication fails. In general, when a car CAN bus is overhauled, a relatively reliable checking method is to pull out all terminal devices and insert the terminal devices one by one, and simultaneously, observe whether a fault reappears. If the fault recurs, the position of the terminal with the problem after the last insertion is the position of the fault. The method is feasible for a miniaturized CAN network, but when the number of terminals on a CAN bus is large, the method brings problems, namely low efficiency, and when the terminals are inserted, new problems CAN be brought by the wrong insertion of the terminals and the mixed insertion of CAN-H and CAN-L.

In the process of implementing the invention, the inventor finds that the prior art has at least the following problems:

the current automobile fault location has the technical problem of low efficiency.

Disclosure of Invention

An object of the embodiments of the present invention is to provide a method and a device for locating a fault of an automobile bus, and an automobile detection system and method, which can improve the efficiency of locating an automobile fault.

In a first aspect, an embodiment of the present invention provides a method for locating a fault of an automobile bus, where the method includes:

acquiring a topological network among electronic control units in an automobile, wherein the electronic control units are connected through a bus;

determining reference nodes in the topological network, wherein the reference nodes comprise a first reference node and/or a second reference node; the first reference nodes are nodes which are directly connected with a backbone path in the topological network and have no child nodes, and two adjacent first reference nodes are spaced by M-1 nodes; the second reference nodes are nodes which are connected with the trunk path through father nodes, and two adjacent second reference nodes are spaced by M-1 nodes; wherein M is a search step length and M is a positive integer;

determining a key node according to the reference node, wherein when the key node is in a disconnected state in the topological network, two network segments which are not communicated with each other exist in the topological network;

and if a fault exists in one of the two network segments when one key node is disconnected, locating the fault in the network segment.

In some embodiments, the determining a reference node in the topological network comprises:

determining a first terminal node and a second terminal node, wherein in the topological network, a path between the first terminal node and the second terminal node is the longest, and a link between the first terminal node and the second terminal node is a backbone path;

determining a weight for each network node between the first terminal node and a second terminal node;

and searching from the first terminal node to the second terminal node according to the searching step length M, and determining the reference node.

In some embodiments, said determining a weight for each network node between said first and second terminal nodes comprises:

and determining the weight of each network node according to the number of other network nodes connected by the link between the network node and the backbone path.

In some embodiments, the determining the weight of each network node according to the number of other network nodes connected to the link between the network node and the backbone path includes:

if the link from a certain network node to the main path is not connected with other network nodes, determining the weight of the network node to be 1;

and if the number of other network nodes connected by the link between a certain network node and the main path is n-1, determining the weight of the network node as n, wherein n is a positive integer and is more than or equal to 2.

In some embodiments, said searching in the direction from the first terminal node to the second terminal node according to the search step size to determine a reference node comprises:

setting a counter, and initializing the reading of the counter to be 1;

judging whether a network node on a backbone path from the first terminal node to the second terminal node has a child node or not;

if yes, determining that at least one branch link exists in the topology network, and determining a second reference node according to the weight of the network node of the at least one branch link;

if not, starting searching from the first terminal node, adding 1 to the reading of the counter every time the network node passes through, and determining the network node corresponding to the reading of the counter being the integral multiple of the searching step length as a first reference node until the searching reaches the second terminal node.

In some embodiments, said determining a second reference node according to the weight of the network node of the at least one branch link comprises:

and according to the weight of each network node on a certain branch link, determining the network node corresponding to the integer multiple of the search step length with the weight as a second reference node, and recursively searching other branches of each branch link until all network nodes on all branch links are traversed.

In some embodiments, the determining a key node according to the position of the reference node includes:

and acquiring a disconnectable position corresponding to the position of the reference node, and determining the disconnectable position as the key node.

In some embodiments, the method further comprises:

dividing a topological network between the electronic control units into at least two sub-network segments according to the key nodes;

when a network fault occurs, the key nodes are disconnected one by one, and the sub-network segments with the network fault are determined according to whether the network fault is eliminated;

and carrying out fault troubleshooting on the network nodes in the sub-network segments so as to determine the network nodes with faults.

In some embodiments, the method further includes determining whether the network failure is eliminated, specifically including:

judging whether loop resistance in the topology network is normal, if so, determining that the network fault is eliminated, and if not, determining that the network fault is not eliminated;

or judging whether the bus waveform of the topology network is recovered to be normal, if so, determining that the network fault is eliminated, and if not, determining that the network fault is not eliminated.

In a second aspect, an embodiment of the present invention provides a diagnostic apparatus, including: main control unit and communication interface, communication interface is used for the communication connection car, the car includes the topological network between the electronic control unit, the topological network includes a plurality of network nodes, main control unit includes:

at least one processor; and

a memory communicatively coupled to the at least one processor; wherein the content of the first and second substances,

the memory stores instructions executable by the at least one processor to enable the at least one processor to perform the method for fault location of an automotive bus as described above.

In a third aspect, an embodiment of the present invention provides an automobile detection system, which is applied to an automobile, where the automobile includes an automobile control unit system, the automobile control unit system includes a plurality of automobile control units, and the automobile detection system includes:

the diagnostic device as described above, communicatively coupled to the vehicle control unit system;

and the oscilloscope is connected with the diagnosis equipment and is used for acquiring the bus waveform of the topology network.

In a fourth aspect, an embodiment of the present invention provides an automobile detection method, which is applied to the automobile detection system described above, where the method includes:

the diagnostic equipment scans the automobile control unit system to obtain a communication fault code;

the oscilloscope obtains the communication fault code sent by the diagnostic equipment and obtains the bus waveform of the topology network so as to determine the fault category;

the method comprises the steps that a diagnosis device obtains a topological network among electronic control units in an automobile, determines key nodes in the topological network, and divides the topological network into a plurality of sub-network segments according to the key nodes;

when a network fault occurs in the diagnostic equipment, the key nodes are disconnected one by one, and a sub-network segment with the network fault is determined according to whether the bus waveform of the topology network acquired by the oscilloscope is recovered to be normal or not;

and the diagnostic equipment carries out fault troubleshooting on the network nodes in the sub-network segments so as to determine the network nodes with faults.

In a fifth aspect, the embodiment of the present invention provides a non-volatile computer-readable storage medium, which stores computer-executable instructions for causing a diagnostic device to execute the above-mentioned fault location method for an automobile bus.

In a sixth aspect, an embodiment of the present invention provides a computer program, which contains program instructions, when the program instructions are executed by one or more processors in a diagnosis device, the diagnosis device executes the above-mentioned fault location method for a vehicle bus.

The embodiment of the invention has the beneficial effects that: in contrast to the prior art, an embodiment of the present invention provides a method for locating a fault of an automotive bus, where the method includes: acquiring a topological network among electronic control units in an automobile, wherein the electronic control units are connected through a bus; determining reference nodes in the topological network, wherein the reference nodes comprise a first reference node and/or a second reference node; the first reference nodes are nodes which are directly connected with a backbone path in the topological network and have no child nodes, and two adjacent first reference nodes are spaced by M-1 nodes; the second reference nodes are nodes which are connected with the trunk path through father nodes, and two adjacent second reference nodes are spaced by M-1 nodes; wherein M is a search step length and M is a positive integer; determining a key node according to the reference node, wherein when the key node is in a disconnected state in the topological network, two network segments which are not communicated with each other exist in the topological network; and if a fault exists in one of the two network segments when one key node is disconnected, locating the fault in the network segment. By determining the key node and positioning the network section where the fault is located, the embodiment of the invention can improve the efficiency of positioning the fault of the automobile.

Drawings

One or more embodiments are illustrated by way of example in the accompanying drawings, which correspond to the figures in which like reference numerals refer to similar elements and which are not to scale unless otherwise specified.

FIG. 1 is a schematic structural diagram of an automotive inspection system according to an embodiment of the present invention;

FIG. 2 is a schematic flow chart illustrating a method for locating a fault of an automobile bus according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a high-speed CAN network structure according to an embodiment of the present invention;

fig. 4 is a schematic diagram of a controller area network according to an embodiment of the present invention after being divided;

FIG. 5 is a detailed flowchart of step S10 in FIG. 2;

fig. 6 is a schematic diagram of a topology of a controller area network according to an embodiment of the present invention;

FIG. 7 is a detailed flowchart of step S23 in FIG. 5;

FIG. 8 is a schematic diagram of an automotive diagnostic bus and an on-line CAN bus provided by an embodiment of the present invention;

FIG. 9 is a schematic flow chart illustrating a method for detecting a vehicle according to an embodiment of the present invention;

fig. 10 is a schematic structural diagram of a diagnostic apparatus according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that, if not conflicted, the various features of the embodiments of the invention may be combined with each other within the scope of protection of the invention. Additionally, while functional block divisions are performed in apparatus schematics, with logical sequences shown in flowcharts, in some cases, steps shown or described may be performed in sequences other than block divisions in apparatus or flowcharts. The terms "first", "second", "third", and the like used in the present invention do not limit data and execution order, but distinguish the same items or similar items having substantially the same function and action.

Before the present invention is explained in detail, terms and expressions referred to in the embodiments of the present invention are explained, and the terms and expressions referred to in the embodiments of the present invention are applied to the following explanations.

(1) A CAN bus, i.e., a Controller Area Network (CAN), refers to a serial communication protocol bus for real-time applications, which CAN transmit signals using twisted pair wires, and is one of the most widely used field buses in the world. The CAN protocol is used for communication between various components in an automobile, thereby replacing expensive and bulky wiring harnesses. The robustness of the protocol extends its use to other automation and industrial applications. The features of the CAN protocol include serial data communication for integrity, real-time support, transmission rates up to 1Mb/s, and 11-bit addressing and error detection capabilities.

(2) An Electronic Control Unit (ECU), also called a "traveling computer" or a "vehicle-mounted computer", is a microcomputer controller specially used for a vehicle, also called a single chip microcomputer specially used for the vehicle. It is the same as common single-chip microcomputer, and is composed of microprocessor (CPU), memory (ROM or RAM), input/output interface (I/O), A/D converter and large scale integrated circuit for shaping and driving.

(3) CAN-H, refers to the CAN bus H line, which is the high data line in the CAN bus.

(4) CAN-L, refers to the CAN bus L line, which is the lower data line in the CAN bus.

(5) PT-CAN refers to a high-speed CAN bus of an automobile power assembly.

(6) Local Interconnect Network (LIN) is a low-cost serial communication Network used for realizing control of a distributed electronic system in an automobile. The aim of LIN is to provide ancillary functions to existing automotive networks (for example the CAN bus), so the LIN bus is an ancillary bus network. The use of a LIN bus for communication between smart sensors and brakes, for example, CAN provide significant cost savings in applications where the bandwidth and versatility of the CAN bus is not required. In addition to the basic protocols and physical layers defined in the LIN specification, development tools and application software interfaces are also defined. LIN communication is based on sci (uart) data format, using single master/multiple slave mode. Only one 12V signal bus and one node synchronous clock line without a fixed time reference are used.

(7) FlexRay, which refers to an automobile internal network communication protocol, CAN also provide a plurality of reliability characteristics that CAN networks do not have. Especially, the redundant communication capability of the FlexRay can realize the complete copying of network configuration through hardware and the progress monitoring. FlexRay also provides flexible configuration and can support a variety of topologies, such as bus, star, and hybrid topologies. Designers can configure distributed systems by combining two or more of these types of topologies. Each FlexRay node comprises a controller and a driver component. The controller component includes a host processor and a communication controller. The driver components typically include a bus driver and a bus guardian (optional). The bus driver connects the communication controller to the bus and the bus guardian monitors the connection to the bus. The host informs the bus guardian that the communications controller has allocated those time slots. The bus guardian then only allows the communication controller to transmit data in these time slots and activates the bus driver. If the bus monitor finds that the time sequence has an interval, the connection of the communication channel is disconnected.

In the embodiment of the present invention, the diagnostic device may be a mobile terminal, which may be a hardware device having various operating systems, such as a smart phone, a tablet Computer, and a Personal digital assistant, or may also be a Personal Computer (PC). The fault positioning method of the automobile bus is realized based on one or more processors of the diagnosis equipment.

Referring to fig. 1, fig. 1 is a schematic structural diagram of an automotive diagnostic system according to an embodiment of the present invention;

as shown in fig. 1, the automobile diagnosis system 110 is communicatively connected to an automobile 120, wherein the automobile diagnosis system 110 includes a diagnosis device 111, a communication interface 112, and an oscilloscope 113, the diagnosis device 111 is communicatively connected to the automobile 120 through the communication interface 112, and the oscilloscope 113 is also communicatively connected to the automobile 120 through the communication interface 112.

In the embodiment of the present invention, the diagnostic device 111 includes a main control CPU, a display screen, a touch screen, a memory, various communication interfaces, and a communication device (supporting CAN communication protocol) for communicating with an automobile. The oscilloscope supports measurement of voltage, current, resistance, frequency and the like, supports a trigger function, and can store waveform data. The application software of the diagnostic instrument comprises automobile diagnostic software, oscilloscope measurement software, automobile maintenance data or maintenance guide. In the running process of the automobile diagnosis software, the measurement function of the oscilloscope can be called, data are extracted from the application of the oscilloscope, and the next maintenance analysis is carried out by matching with a maintenance guide.

In an embodiment of the invention, the communication interface 112 comprises a DLC interface, through which the car 120 is connected to the diagnostic device 111 during the test (standard OBD interface, 16PIN), which DLC interface supports the SAE J1962/ISO 15031-3 standard, typically PIN6 and PIN14 as diagnostic CAN data interfaces. In the diagnostic device 111, an interface is provided for oscilloscope probe contacts. For the case where the internal CAN bus is not connected to the DLC interface, the oscilloscope probes need to be connected to the connection points recommended by the diagnostic device 111.

In an embodiment of the present invention, the oscilloscope 113 comprises an oscilloscope probe for measuring the communication waveform of a network of a controller area network.

In the ECU communication of the automobile electronic parts, a CAN bus plays a very important role, particularly in a power assembly part, and the communication between ECUs is completed through a high-speed PT-CAN. The high-speed CAN bus is a broadcast network, consists of two data buses CAN-H and CAN-L, and transmits differential signals, wherein, when any one data line is in fault, open circuit or short circuit, the whole network communication fails. In general, when a car CAN bus is overhauled, a relatively reliable checking method is to pull out all terminal devices and insert the terminal devices one by one, and simultaneously, observe whether a fault reappears. If the fault reappears, the position of the terminal with the problem after the last insertion is the position of the fault. The method is feasible for a miniaturized CAN network, but when the number of terminals on a CAN bus is large, the method brings problems, namely low efficiency, and when the terminals are inserted, new problems CAN be brought by the wrong insertion of the terminals and the mixed insertion of CAN-H and CAN-L. How to provide an efficient and trouble-saving fault point detection scheme is very important for troubleshooting of CAN bus faults.

Aiming at the technical problem of low efficiency of automobile fault location in the prior art, the embodiment of the invention provides a fault location method and diagnosis equipment of an automobile bus, and an automobile detection system and method, so as to improve the efficiency of automobile fault location.

Specifically, please refer to fig. 2, fig. 2 is a schematic flow chart of a method for locating a fault of an automobile bus according to an embodiment of the present invention;

the fault positioning method of the automobile bus is applied to a Controller Area Network (CAN), wherein the CAN comprises a plurality of Network nodes which are in communication connection through a CAN bus.

As shown in fig. 2, the method for locating a fault of an automobile bus includes:

step S10: acquiring a topological network among electronic control units in an automobile, wherein the electronic control units are connected through a bus;

it is understood that each electronic control unit corresponds to a network node in the topological network, and a plurality of electronic control units are directly connected in communication in the manner of the topological network. Specifically, referring to fig. 3 again, fig. 3 is a schematic structural diagram of a high-speed CAN network structure according to an embodiment of the present invention;

as shown in fig. 3, the high-speed CAN bus is composed of two lines, CAN-H and CAN-L, and 120 Ω resistors are connected to the two terminals, respectively. If the CAN network is normal, the power supply VCC is disconnected, and the resistance R of the whole loop measured at the terminal point X1, X2 of the gateway ECU should be around 60 Ω. If a fault, short circuit or open circuit occurs on the bus, the measured value of the resistance R will vary greatly. Under the condition of bus abnormity, the waveform on the bus can be analyzed by an oscilloscope in the communication state, and the bus fault is judged to be an open circuit, a short circuit to the ground, a short circuit to a power supply or a mutual short circuit. After the type of the fault is known, the specific location of the fault occurring in the network needs to be located.

Referring to fig. 4 again, fig. 4 is a schematic diagram of a controller area network according to an embodiment of the present invention after being divided;

as shown in fig. 4, there are many network nodes on the CAN bus, and how to quickly determine the specific location of the fault is very challenging. Usually, some key nodes are selected in the network, the network is divided into a plurality of sub-network segments, the network segment in which the fault occurs is firstly checked, and then the network segment in which the fault occurs is searched, so that the fault occurrence range is gradually reduced, and the efficiency of positioning the fault position is improved.

As shown in fig. 4, the topology network of the controller lan is formed by 15 network nodes in total from Node1-Node15, wherein four network locations X01, X02, X03, and X04 divide the controller lan into five sub-network segments, four network locations X01, X02, X03, and X04 are key nodes in the controller lan, and when a network fault occurs, the key nodes are gradually disconnected, and whether the network fault phenomenon disappears is observed, so as to determine which sub-network segment the network fault occurs in, thereby achieving the purpose of reducing the search range. For example, when a network failure occurs in the network Node7, and the key Node X03 is disconnected, the bus communication of the gateway segment is recovered, so as to determine that the network failure occurs in the range of the subnet segment covered by the key Node X03 (including subnet segment 2 and subnet segment 3); after the key node X02 is continuously disconnected, the key node X03 is connected, and the gateway segment fault reappears, so that the fault in the sub-network segment 2 can be disconnected, and the network node with the fault can be gradually searched in the sub-network segment 2 to eliminate the fault.

Step S20: determining reference nodes in the topological network, wherein the reference nodes comprise a first reference node and/or a second reference node;

the first reference nodes are nodes which are directly connected with a backbone path in the topological network and have no child nodes, and two adjacent first reference nodes are spaced by M-1 nodes; the second reference nodes are nodes which are connected with the trunk path through father nodes, and two adjacent second reference nodes are spaced by M-1 nodes; wherein M is a search step length and M is a positive integer;

specifically, referring back to fig. 5, fig. 5 is a detailed flowchart of step S10 in fig. 2;

as shown in fig. 5, the step S20: determining a reference node in the topological network, comprising:

step S21: determining a first terminal node and a second terminal node, wherein in the topological network, a path between the first terminal node and the second terminal node is the longest, and a link between the first terminal node and the second terminal node is a backbone path;

referring to fig. 6, fig. 6 is a schematic diagram of a topology of a controller area network according to an embodiment of the present invention;

as shown in fig. 6, the path between the network Node11 and the network Node15 is the longest, so that the network Node11 is determined to be the first terminal Node, and the network Node15 is determined to be the second terminal Node, or the network Node15 is determined to be the first terminal Node and the network Node11 is determined to be the second terminal Node, in the embodiment of the present invention, the network Node11 is the first terminal Node, and the network Node15 is the second terminal Node, and the link between the network Node11 and the network Node15 is the backbone path.

Step S22: determining a weight for each network node between the first terminal node and a second terminal node;

specifically, the determining the weight of each network node between the first terminal node and the second terminal node includes:

Specifically, the determining the weight of each network node according to the number of other network nodes connected to the link between the network node and the trunk path includes:

As shown in fig. 6, if no other network Node is connected to the link from the network Node1 to the backbone path, the weight of the network Node1 is determined to be 1, and the link from the network Node2 to the backbone path is connected to the network Node1, that is, 1 network Node, so that the weight of the network Node2 is determined to be 1+ 1-2, and so on, the weight of the network Node3 is determined to be 3, the weight of the network Node4 is determined to be 4, the weights of the network nodes 5-10 are all 1, and the weights of the network nodes Node12-14 are all 1.

Step S23: searching from the first terminal node to the second terminal node according to the search step length M to determine the reference node;

specifically, please refer to fig. 7 again, fig. 7 is a detailed flowchart of step S23 in fig. 5;

as shown in fig. 7, the step S23: according to the search step length M, searching from the first terminal node to the second terminal node, and determining the reference node, including:

step S231: setting a counter, and initializing the reading of the counter to be 1;

specifically, assuming that the counter is Count, the counter Count is initialized to 1.

Step S232: judging whether a network node on a backbone path from the first terminal node to the second terminal node has a child node or not;

specifically, the child node is a next node connected to a certain network node, for example: as shown in fig. 6, the network Node2 is a child Node of the network Node1, and the network Node3 is a child Node of the network Node2, wherein the network Node on the backbone path from the first terminal Node to the second terminal Node means that the network Node is directly connected to the backbone path and the link between the network Node and the backbone path does not include other network nodes, for example: the network nodes Node1, Node5-Node10, Node12-14 and Node16 shown in FIG. 6.

Judging whether a network node on a backbone path from the first terminal node to the second terminal node has a child node, if so, entering step S233; if not, go to step S234;

step S233: determining that at least one branch link exists in the topological network, and determining a second reference node according to the weight of the network node of the at least one branch link;

specifically, the determining the second reference node according to the weight of the network node of the at least one branch link includes:

It can be understood that the second reference node refers to a reference node on a branch link, and specifically, if a network node on a trunk path from the first terminal node to the second terminal node has a child node, it is determined that at least one branch link exists in the topological network; and determining the network nodes corresponding to the integer multiple of the searching step length with the weight as second reference nodes according to the weight of each network node on a certain branch link, and recursively searching each branch link until all network nodes on all branch links are traversed.

Specifically, as shown in fig. 6, a child Node exists in the network Node1, and Node1-Node2-Node3-Node4 constitutes a branch link, at this time, a weight of each network Node on the branch link is obtained, if a network Node whose weight is an integer multiple of a search step exists, the network Node is determined as a reference Node, and each branch link is recursively searched until all network nodes on all branch links are traversed, where the recursive search refers to that, after all network nodes on one branch link are searched according to each branch link in a search direction from the first terminal Node to the second terminal Node, the parent Node of the branch link is returned, and other branches on the branch link are searched to traverse the branch link, for example: node1-Node2-Node3-Node4 forms a branch link, and if there are other branches on the branch link, after searching Node1-Node2-Node3-Node4, returning Node1 and starting to search other network nodes from Node1, so as to traverse the branch link. Through recursive search, the invention can better determine the reference node and is beneficial to better segmenting the network.

Step S234: and starting searching from the first terminal node, adding 1 to the reading of the counter every time a network node passes through, and determining the network node corresponding to the reading of the counter which is the integral multiple of the searching step length as a first reference node until the searching reaches the second terminal node.

Specifically, assume that the search step size is M, where M is a positive integer and M ≧ 2, preferably, the search step size M is 3 or 4.

It should be understood that, the first reference Node refers to a reference Node on the backbone path, a network Node not including a child Node is searched from the first terminal Node, and if the search step is 4, the network Node not including a child Node is searched from the first terminal Node11, and every time a network Node passes through, the counter Count +1 is counted, that is, the counter Count is 2 when the network Node10 is searched, the counter Count is 3 when the network Node9 is searched, the counter Count is 4 when the network Node8 is searched, and when the reading of the counter is an integer multiple of the search step, the network Node8 is determined to be the reference Node.

Step S30: determining a key node according to the reference node, wherein when the key node is in a disconnected state in the topological network, two network segments which are not communicated with each other exist in the topological network;

specifically, the determining a key node according to the position of the reference node includes:

and acquiring a disconnectable position near the position of the reference node, and determining the disconnectable position as the key node, wherein after the disconnectable position is disconnected, two network segments which are not communicated with each other exist in the topological network. Specifically, the disconnectable locations include plug locations, and after each plug location is disconnected, the controller area network is divided into two networks that are not connected to each other.

Specifically, a search algorithm for determining a key node in the controller area network according to the embodiment of the present invention is described with reference to fig. 6, where the search algorithm includes the following steps:

(1) on the backbone path, searching a reference Node from the first terminal Node to the second terminal Node, that is, searching from the network Node11 to the network Node15 in fig. 6, where the counter Count is 1 and the reference Node searching step size M is 4;

(2) if the network Node on the backbone path also has a child Node (for example, Node1 has a child Node, and the weight is 1, as a child Node on the backbone path), the child Node is taken as a reference Node and recorded, and the search for the branch is transferred to step (5);

(3) if the network node on the main path has no child node, the counter Count is added by 1, and if the Count is an integral multiple of M, the network node is used as a reference node;

(4) searching each network Node on the backbone path until reaching a second terminal Node, namely a network Node 15;

(5) branch search: searching from a node with the weight of 1, and recording the node as a reference node when the weight is an integral multiple of M; if there is a branch on the branch, performing a recursive search according to step (5);

(6) finding a location near the searched reference node that can be disconnected: if the plug is arranged and the disconnected network is divided into two disconnected networks, the plug position is a key node.

In the embodiment of the invention, in the actual operation, the searching step length M of the reference node is 3 or 4, so that the searching range between the segments can be reduced, the contraction range in the segments can be reduced, and N/M + M-2 times of positioning can be carried out in the worst case, wherein N is the number of nodes in the controller local area network.

Step S40: if a fault exists in one of the two network segments when one key node is disconnected, the fault is positioned in the network segment;

in an embodiment of the present invention, the method further comprises:

Specifically, the plurality of key nodes divide the controller area network into a plurality of sub-network segments, and when a network fault occurs, the key nodes are disconnected one by one to determine the sub-network segment with the network fault according to whether the network fault is eliminated;

specifically, the determining whether the network fault is eliminated includes:

judging whether the loop resistance in the controller local area network is normal or not, if so, determining that the network fault is eliminated, and if not, determining that the network fault is not eliminated;

or judging whether the bus waveform of the controller local area network is recovered to be normal or not, if so, determining that the network fault is eliminated, and if not, determining that the network fault is not eliminated.

In an embodiment of the present invention, the method further comprises: and carrying out fault troubleshooting on the network nodes in the sub-network segments to determine the network nodes with faults.

In the embodiment of the present invention, each of the key nodes corresponds to at least one sub-network segment.

In an embodiment of the present invention, a method for locating a fault of an automobile bus is provided, where the method includes: acquiring a topological network among electronic control units in an automobile, wherein the electronic control units are connected through a bus; determining reference nodes in the topological network, wherein the reference nodes comprise a first reference node and/or a second reference node; the first reference nodes are nodes which are directly connected with a backbone path in the topological network and have no child nodes, and two adjacent first reference nodes are spaced by M-1 nodes; the second reference nodes are nodes which are connected with the trunk path through father nodes, and two adjacent second reference nodes are spaced by M-1 nodes; wherein M is a search step length and M is a positive integer; determining a key node according to the reference node, wherein when the key node is in a disconnected state in the topological network, two network segments which are not communicated with each other exist in the topological network; and if a fault exists in one of the two network segments when one key node is disconnected, locating the fault in the network segment. By determining the key node and positioning the network section where the fault is located, the embodiment of the invention can improve the efficiency of positioning the fault of the automobile.

Referring to fig. 8 again, fig. 8 is a schematic diagram of an automobile diagnostic bus and an on-line CAN bus according to an embodiment of the present invention;

as shown in fig. 8, the DLC interface is connected to a gateway via a diagnostic bus, which includes a CAN bus and a LIN bus, the gateway also being connected to other components via a FlexRay communication protocol, and in a motor vehicle the diagnostic interface is usually led out via a 16PIN DLC interface. For some vehicle types, the CAN bus is connected with the DLC interface, but for most vehicle types, the diagnosis bus CAN access the internal CAN bus only through the gateway. If the CAN bus waveform is measured by an oscilloscope, a measurement point needs to be provided, please refer back to fig. 4, and the measurement CAN be performed at X3001 and X3002 of the gateway.

In the embodiment of the invention, the automobile detection system comprises a diagnosis device, an oscilloscope and a multimeter. The diagnosis equipment comprises a main control MCU, a display screen, a touch screen, a memory, various communication interfaces and a communication device (supporting CAN communication protocol) for communicating with the automobile. The oscilloscope supports measurement of voltage, current, resistance, frequency and the like, supports a trigger function, and can store waveform data. The application software of the diagnostic instrument comprises automobile diagnostic software, oscilloscope measurement software, automobile maintenance data or maintenance guide. In the embodiment of the invention, the diagnosis equipment comprises automobile diagnosis application software and oscilloscope software, and during the operation of the diagnosis software, the oscilloscope measurement function can be called, data can be extracted from the oscilloscope application, and the next maintenance analysis can be carried out by matching with a maintenance guide. In an embodiment of the present invention, the diagnostic device and the oscilloscope may be integrated into one electronic device, for example: the diagnostic device comprises an oscilloscope for realizing the measurement function of the oscilloscope, or the electronic device comprises the diagnostic device and the oscilloscope for realizing all the functions of the diagnostic device and the oscilloscope.

During the test, the vehicle is connected to the diagnostic device via a DLC interface (standard OBD interface, 16PIN), which supports the SAE J1962/ISO 15031-3 standard, typically PIN6 and PIN14 as diagnostic CAN data interfaces. In the diagnostic equipment, an interface is provided for the contact of the oscilloscope probe. For the case where the internal CAN bus is not connected to the DLC interface, the oscilloscope probes need to be connected to the connection points recommended by the diagnostic equipment.

Referring to fig. 9, fig. 9 is a schematic flow chart of a vehicle detection method according to an embodiment of the present invention;

as shown in fig. 9, the automobile detection method is applied to the automobile detection system, and the method includes:

step S91: the diagnostic equipment scans the automobile control unit system to obtain a communication fault code;

specifically, the automobile detection method is applied to an automobile which comprises an automobile control unit system (ECU system), and the diagnosis device is in communication connection with the automobile control unit system, for example: scanning the automobile control unit system through a DLC interface to obtain a communication fault code, wherein a diagnosis device scans an automobile ECU system through the DLC interface and discovers the communication fault code or the ECU system cannot be connected, the diagnosis device comprises diagnosis software, and the diagnosis software starts a maintenance guide to guide a user to carry out communication fault detection;

step S92: the oscilloscope obtains the communication fault code sent by the diagnostic equipment and obtains the bus waveform of the topology network so as to determine the fault category;

specifically, the maintenance guide prompts a user to start a measuring tool, the waveform on the CAN communication line is captured through an oscilloscope, and the CAN fault is judged to belong to the fault categories of ground short circuit, power supply short circuit, lead short circuit, bus open circuit, terminal resistance abnormity, branch line overlong and the like through waveform comparison analysis;

step S93: the method comprises the steps that a diagnosis device obtains a topological network among electronic control units in an automobile, determines key nodes in the topological network, and divides the topological network into a plurality of sub-network segments according to the key nodes;

specifically, a first terminal node and a second terminal node are determined, wherein in the controller area network, a path between the first terminal node and the second terminal node is the longest, and a link between the first terminal node and the second terminal node is a trunk path; determining a weight for each network node between the first terminal node and a second terminal node; presetting a search step length, searching from the first terminal node to the second terminal node, and determining a reference node; and determining a key node according to the position of the reference node, and dividing the topological network into a plurality of sub-network segments based on the key node.

Step S94: when a network fault occurs in the diagnostic equipment, the key nodes are disconnected one by one, and a sub-network segment with the network fault is determined according to whether the bus waveform of the topology network acquired by the oscilloscope is recovered to be normal or not;

specifically, the maintenance guide calculates key nodes of the CAN bus and key nodes which need to be verified at present through a topological graph, namely a topological network, of the controller local area network, prompts a user to break the key nodes and then analyzes the waveform of the bus, and determines the sub-network segment with faults through the key nodes broken by the user, the key nodes broken by the diagnostic equipment and the key nodes which are connected subsequently and broken.

Step S95: and the diagnostic equipment carries out fault troubleshooting on the network nodes in the sub-network segments so as to determine the network nodes with faults.

Specifically, each network node in the sub-network segment is examined to determine the network node with the fault.

Specifically, the automobile detection method comprises the following steps:

(1) the diagnosis equipment scans the automobile ECU system through the DLC interface, if a communication fault code exists or the ECU system cannot be connected, the diagnosis software starts a maintenance guide to guide a user to carry out communication fault detection;

(2) the maintenance guide prompts a user to start a CAN communication mode or actively sends data to a CAN bus through a CAN protocol;

(3) the maintenance guide prompts a user to start a measuring tool, the waveform on the CAN communication line is captured through the oscilloscope, and the CAN fault is judged to belong to the fault categories of ground short circuit, power supply short circuit, lead short circuit, bus open circuit, terminal resistance abnormity, branch line overlong and the like through waveform comparison analysis;

(4) the maintenance guide calculates key nodes of the CAN bus and key points which need to be verified at present through the CAN topological graph, and prompts a user to analyze the bus waveform after disconnecting the key nodes;

(5) the user disconnects the key node;

(6) the user starts the oscilloscope to measure the communication waveform of the network after the disconnection, if the waveform is normal, the step (7) is carried out, otherwise, the step (9) is carried out;

(7) searching a network node with a fault at a disconnection side, calculating a next key node needing to be disconnected, namely a disconnection point, at the disconnection side by a maintenance guide, and marking a network segment of the current disconnection point and a network segment of the next disconnection point as an X segment;

(8) and (5) connecting the current disconnection point, continuing the methods in the steps (5) and (6), and judging whether the fault is in the X section. If the judgment principle is that the waveform of the oscilloscope is abnormal, the fault is in an X section, otherwise, the next key node needing to be disconnected is calculated until the fault point is found or all key nodes are searched;

(9) calculating the next key node to be disconnected, and turning to the step (5);

in an embodiment of the present invention, by providing an automobile detection method applied to the automobile detection system described in the above embodiment, the method includes: the diagnostic equipment scans the automobile control unit system to obtain a communication fault code; the oscilloscope obtains the communication fault code sent by the diagnostic equipment and obtains the bus waveform of the topology network so as to determine the fault category; the method comprises the steps that a diagnosis device obtains a topological network among electronic control units in an automobile, determines key nodes in the topological network, and divides the topological network into a plurality of sub-network segments according to the key nodes; when a network fault occurs in the diagnostic equipment, the key nodes are disconnected one by one, and a sub-network segment with the network fault is determined according to whether the bus waveform of the topology network acquired by the oscilloscope is recovered to be normal or not; and the diagnostic equipment carries out fault troubleshooting on the network nodes in the sub-network segments so as to determine the network nodes with faults. The embodiment of the invention can improve the efficiency of automobile fault positioning by determining key nodes, determining the sub-network segment with the network fault, and carrying out fault troubleshooting on the network nodes in the sub-network segment to determine the network node with the fault.

Referring to fig. 10, fig. 10 is a schematic diagram of a hardware structure of a diagnostic apparatus according to various embodiments of the present invention;

as shown in fig. 10, the diagnostic device 100 includes, but is not limited to: the diagnostic apparatus 100 further includes a radio frequency unit 101, a network module 102, an audio output unit 103, an input unit 104, a sensor 105, a display unit 106, a user input unit 107, an interface unit 108, a memory 109, a processor 1010, a power supply 1011, and the like. Those skilled in the art will appreciate that the configuration of the diagnostic device shown in fig. 10 does not constitute a limitation of the diagnostic device, which may include more or fewer components than shown, or some components in combination, or a different arrangement of components. In the embodiment of the present invention, the diagnosis device includes, but is not limited to, a television, a mobile phone, a tablet computer, a notebook computer, a palm computer, a vehicle-mounted terminal, a wearable device, a pedometer, and the like.

The processor 1010 is used for acquiring a topological network among electronic control units in the automobile, wherein the electronic control units are connected through a bus;

determining reference nodes in the topological network, wherein the reference nodes comprise a first reference node and/or a second reference node; the first reference nodes are nodes which are directly connected with a backbone path in the topological network and have no child nodes, and two adjacent first reference nodes are spaced by M-1 nodes; the second reference nodes are nodes which are connected with the trunk path through father nodes, and two adjacent second reference nodes are spaced by M-1 nodes; wherein M is a search step length and M is a positive integer; determining a key node according to the reference node, wherein when the key node is in a disconnected state in the topological network, two network segments which are not communicated with each other exist in the topological network; and if a fault exists in one of the two network segments when one key node is disconnected, locating the fault in the network segment.

In the embodiment of the invention, the network section where the fault is located is positioned by determining the key node, and the embodiment of the invention can improve the efficiency of positioning the fault of the automobile.

It should be understood that, in the embodiment of the present invention, the radio frequency unit 101 may be used for receiving and sending signals during a message transmission or call process, and specifically, after receiving downlink data from a base station, the downlink data is processed by the processor 1010; in addition, the uplink data is transmitted to the base station. Typically, radio frequency unit 101 includes, but is not limited to, an antenna, at least one amplifier, a transceiver, a coupler, a low noise amplifier, a duplexer, and the like. In addition, the radio frequency unit 101 can also communicate with a network and other devices through a wireless communication system.

The diagnostic device 100 provides wireless broadband internet access to the user via the network module 102, such as assisting the user in emailing, browsing web pages, and accessing streaming media.

The audio output unit 103 may convert audio data received by the radio frequency unit 101 or the network module 102 or stored in the memory 109 into an audio signal and output as sound. Also, the audio output unit 103 may also provide audio output related to a specific function performed by the diagnostic apparatus 100 (e.g., a call signal reception sound, a message reception sound, etc.). The audio output unit 103 includes a speaker, a buzzer, a receiver, and the like.

The input unit 104 is used to receive an audio or video signal. The input Unit 104 may include a Graphics Processing Unit (GPU) 1041 and a microphone 1042, and the Graphics processor 1041 processes a target image of a still picture or video obtained by an image capturing device (e.g., a camera) in a video capturing mode or an image capturing mode. The processed image frames may be displayed on the display unit 106. The image frames processed by the graphic processor 1041 may be stored in the memory 109 (or other storage medium) or transmitted via the radio frequency unit 101 or the network module 102. The microphone 1042 may receive sound and may be capable of processing such sound into audio data. The processed audio data may be converted into a format output transmittable to a mobile communication base station via the radio frequency unit 101 in case of a phone call mode.

The diagnostic device 100 also includes at least one sensor 105, such as light sensors, motion sensors, and other sensors. Specifically, the light sensor includes an ambient light sensor that can adjust the brightness of the display panel 1061 according to the brightness of ambient light, and a proximity sensor that can turn off the display panel 1061 and/or the backlight when the diagnostic device 100 is moved to the ear. As one of the motion sensors, the accelerometer sensor can detect the magnitude of acceleration in various directions (generally three axes), detect the magnitude and direction of gravity when stationary, and can be used to identify the gesture of the diagnostic device (such as horizontal and vertical screen switching, related games, magnetometer gesture calibration), vibration identification related functions (such as pedometer, tapping), and the like; the sensors 105 may also include fingerprint sensors, pressure sensors, iris sensors, molecular sensors, gyroscopes, barometers, hygrometers, thermometers, infrared sensors, etc., which are not described in detail herein.

The display unit 106 is used to display information input by a user or information provided to the user. The Display unit 106 may include a Display panel 1061, and the Display panel 1061 may be configured in the form of a Liquid Crystal Display (LCD), an Organic Light-Emitting Diode (OLED), or the like.

The user input unit 107 may be used to receive input numeric or character information and generate key signal inputs related to user settings and function control of the diagnostic apparatus. Specifically, the user input unit 107 includes a touch panel 1071 and other input devices 1072. Touch panel 1071, also referred to as a touch screen, may collect touch operations by a user on or near the touch panel 1071 (e.g., operations by a user on or near touch panel 1071 using a finger, stylus, or any suitable object or attachment). The touch panel 1071 may include two parts of a touch detection device and a touch controller. The touch detection device detects the touch direction of a user, detects a signal brought by touch operation and transmits the signal to the touch controller; the touch controller receives touch information from the touch sensing device, converts the touch information into touch point coordinates, sends the touch point coordinates to the processor 1010, and receives and executes commands sent by the processor 1010. In addition, the touch panel 1071 may be implemented in various types, such as a resistive type, a capacitive type, an infrared ray, and a surface acoustic wave. In addition to the touch panel 1071, the user input unit 107 may include other input devices 1072. Specifically, other input devices 1072 may include, but are not limited to, a physical keyboard, function keys (e.g., volume control keys, switch keys, etc.), a trackball, a mouse, and a joystick, which are not described in detail herein.

Further, the touch panel 1071 may be overlaid on the display panel 1061, and when the touch panel 1071 detects a touch operation thereon or nearby, the touch panel 1071 transmits the touch operation to the processor 1010 to determine the type of the touch event, and then the processor 1010 provides a corresponding visual output on the display panel 1061 according to the type of the touch event. Although in fig. 10, the touch panel 1071 and the display panel 1061 are two independent components to implement the input and output functions of the diagnostic device, in some embodiments, the touch panel 1071 and the display panel 1061 may be integrated to implement the input and output functions of the diagnostic device, and is not limited herein.

The interface unit 108 is an interface for connecting an external device to the diagnostic apparatus 100. For example, the external device may include a wired or wireless headset port, an external power supply (or battery charger) port, a wired or wireless data port, a memory card port, a port for connecting a device having an identification module, an audio input/output (I/O) port, a video I/O port, an earphone port, and the like. The interface unit 108 may be used to receive input (e.g., data information, power, etc.) from an external device and transmit the received input to one or more elements within the diagnostic apparatus 100 or may be used to transmit data between the diagnostic apparatus 100 and an external device.

The memory 109 may be used to store software programs as well as various data. The memory 109 may mainly include a program storage area and a data storage area, wherein the program storage area may store an application program 1091 (such as a sound playing function, an image playing function, etc.) and an operating system 1092, etc. required by at least one function; the storage data area may store data (such as audio data, a phonebook, etc.) created according to the use of the cellular phone, and the like. Further, the memory 109 may include high speed random access memory, and may also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other volatile solid state storage device.

The processor 1010 is a control center of the diagnostic apparatus, connects various parts of the entire diagnostic apparatus using various interfaces and lines, and performs various functions of the diagnostic apparatus and processes data by running or executing software programs and/or modules stored in the memory 109 and calling data stored in the memory 109, thereby performing overall monitoring of the diagnostic apparatus. Processor 1010 may include one or more processing units; preferably, the processor 1010 may integrate an application processor, which mainly handles operating systems, user interfaces, application programs, etc., and a modem processor, which mainly handles wireless communications. It will be appreciated that the modem processor described above may not be integrated into processor 1010.

The diagnostic device 100 may further include a power source 1011 (e.g., a battery) for supplying power to various components, and preferably, the power source 1011 may be logically connected to the processor 1010 through a power management system, so as to manage charging, discharging, and power consumption management functions through the power management system.

In addition, the diagnostic apparatus 100 includes some functional modules that are not shown, and will not be described herein.

Preferably, an embodiment of the present invention further provides a diagnostic apparatus, including a processor 1010, a memory 109, and a computer program stored in the memory 109 and capable of running on the processor 1010, where the computer program is executed by the processor 1010 to implement each process of the above-mentioned fault location method embodiment, and can achieve the same technical effect, and in order to avoid repetition, details are not described here again.

The embodiments of the present invention further provide a computer-readable storage medium, where a computer program is stored on the computer-readable storage medium, and when the computer program is executed by one or more processors, the computer program implements each process of the above-mentioned fault location method embodiment, and can achieve the same technical effect, and in order to avoid repetition, the details are not repeated here. The computer-readable storage medium may be a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk.

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 apparatus 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 apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

The above-described embodiments of the apparatus or device are merely illustrative, wherein the unit modules described as separate parts may or may not be physically separate, and the parts displayed as module units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network module units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment.

Through the above description of the embodiments, those skilled in the art will clearly understand that the method of the above embodiments can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware, but in many cases, the former is a better implementation manner. Based on such understanding, the technical solutions of the present invention may be embodied in the form of a software product, which is stored in a storage medium (such as ROM/RAM, magnetic disk, optical disk) and includes instructions for enabling a terminal (which may be a mobile terminal, a personal computer, a server, or a network device) to execute the method according to the embodiments or some parts of the embodiments of the present invention.

Finally, it should be noted that: the embodiments described above with reference to the drawings are only for illustrating the technical solutions of the present invention, and the present invention is not limited to the above-mentioned specific embodiments, which are only illustrative and not restrictive; within the idea of the invention, also technical features in the above embodiments or in different embodiments may be combined, steps may be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in detail for the sake of brevity; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A fault location method for an automotive bus, the method comprising:

2. The method of claim 1, wherein determining the reference node in the topological network comprises:

3. The method of claim 2, wherein determining the weight of each network node between the first terminal node and the second terminal node comprises:

4. The method of claim 3, wherein determining the weight of each network node based on the number of other network nodes connected by links between the network node and the backbone path comprises:

5. The method of claim 4, wherein the searching from the first terminal node to the second terminal node according to the search step size M to determine the reference node comprises:

setting a counter, and initializing the reading of the counter to be 1;

6. The method of claim 5, wherein determining the second reference node according to the weight of the network node of the at least one branch link comprises:

7. The method of claim 2, wherein determining a key node according to the location of the reference node comprises:

8. The method of claim 1, further comprising:

9. The method according to claim 8, wherein the method further comprises determining whether the network failure is resolved, specifically comprising:

10. A diagnostic apparatus, characterized in that the diagnostic apparatus comprises: main control unit and communication interface, communication interface is used for the communication connection car, the car includes the topological network between the electronic control unit, the topological network includes a plurality of network nodes, main control unit includes:

at least one processor; and

the memory stores instructions executable by the at least one processor to enable the at least one processor to perform the method of fault location of an automotive bus of any one of claims 1-9.

11. The utility model provides an automobile detection system, is applied to the car, its characterized in that, the car includes car the control unit system, car the control unit system includes a plurality of car the control unit, automobile detection system includes:

the diagnostic device of claim 10, communicatively coupled to the vehicle control unit system;

12. A car inspection method applied to the car inspection system according to claim 11, the method comprising: