CN112684371B

CN112684371B - Fault positioning method, diagnosis equipment and automobile detection system and method for automobile bus

Info

Publication number: CN112684371B
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: 2023-11-21
Anticipated expiration: 2040-12-07
Also published as: CN112684371A; WO2022121693A1

Abstract

The invention relates to the technical field of terminals, and discloses a fault positioning method and diagnostic equipment for an automobile bus, an automobile detection system and an automobile detection method, wherein the fault positioning method for the automobile bus comprises the following steps: obtaining a topology network among electronic control units in an automobile, wherein the electronic control units are connected through buses; 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 the reference node, wherein when the key node is in a disconnected state in a topology network, two network segments which are not communicated with each other exist in the topology network; if a fault exists in one of the two network segments when a certain key node is disconnected, the fault is positioned in the network segment. By determining the key nodes and locating the network section where the fault is located, the embodiment of the invention can improve the efficiency of locating the fault of the automobile.

Description

Fault positioning method, diagnosis equipment and automobile detection system and method for automobile bus

Technical Field

The present invention relates to the field of automotive technologies, and in particular, to a fault positioning method and diagnostic apparatus for an automotive bus, and an automotive detection system and method.

Background

The controller area network (Controller Area Network, CAN) is one of the most widely used field buses internationally. The CAN bus protocol has become the standard bus for automotive computer control systems and embedded industrial control local area networks, and has the J1939 protocol designed specifically for large trucks and heavy machinery vehicles with CAN as the underlying protocol. In recent years, the high reliability and the 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 communication of automobile electronic parts ECU, CAN bus plays a very important role, especially in the power assembly part, and the communication between the ECUs is completed through high speed PT-CAN.

The high-speed CAN bus is a broadcasting network, and consists of two data buses CAN-H and CAN-L, and transmits differential signals, wherein any one of the data lines fails, is open or short-circuited, and the whole network communication is invalid. In general, when the automobile CAN bus is overhauled, the more reliable inspection method is to pull out all terminal devices and insert the terminal devices one by one, and simultaneously observe whether faults reappear. If the fault is repeated, the last terminal position with the problem after insertion is the position where the fault occurs. The method is feasible for a miniaturized CAN network, but when the number of terminals on a CAN bus is large, the method brings some problems, namely firstly, the efficiency is low, and when the other is inserted, the novel problems CAN be brought by misinsertion of the terminals and mixed insertion of CAN-H and CAN-L.

In carrying out the invention, the inventors have found that the prior art has at least the following problems:

the existing automobile fault positioning has the technical problem of low efficiency.

Disclosure of Invention

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

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

obtaining a topology network among electronic control units in an automobile, wherein the electronic control units are connected through buses;

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 trunk 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 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 disconnection state in the topology network, two network segments which are not communicated with each other exist in the topology network;

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

In some embodiments, the determining a reference node in the topology network includes:

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 longest, and a link between the first terminal node and the second terminal node is a trunk path;

determining a weight of each network node between the first terminal node and the 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, the determining the weight of each network node between the first and second terminal nodes comprises:

the weight of each network node is determined according to the number of other network nodes connected by links 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 by links between the network node and the backbone path includes:

if the link between a certain network node and the trunk path is not connected with other network nodes, determining that the weight of the network node is 1;

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

In some embodiments, the searching from the first terminal node to the second terminal node according to the searching step length, and determining the reference node includes:

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

judging whether a sub-node exists in a network node on a trunk path from the first terminal node to the second terminal node;

if yes, 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;

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

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

according to the weight of each network node on a certain branch chain, determining the network node with the weight being integral multiple of the searching step length as a second reference node, and recursively searching other branches of each branch chain until all network nodes on all branch chains are traversed.

In some embodiments, the determining the key node according to the location 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 topology network between the electronic control units into at least two sub-network segments according to the key nodes;

when a network fault occurs, disconnecting the key nodes one by one, and determining a sub-network segment with the network fault according to whether the network fault is eliminated;

and performing fault troubleshooting on the network nodes in the sub-network segments 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 topological 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 topological 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: the communication interface is used for being connected with the automobile in a communication mode, the automobile comprises a topology network among electronic control units, the topology network comprises a plurality of network nodes, and the main controller comprises:

at least one processor; and

a memory communicatively coupled to the at least one processor; wherein,

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

In a third aspect, an embodiment of the present invention provides an automobile detection system applied to an automobile, the automobile including an automobile control unit system including a plurality of automobile control units, the automobile detection system including:

A diagnostic device as described above, said diagnostic device being communicatively connected to said automotive control unit system;

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

In a fourth aspect, an embodiment of the present invention provides an automobile detection method, applied to an automobile detection system as described above, the method including:

the diagnosis equipment scans the automobile control unit system to acquire a communication fault code;

the oscilloscope acquires a communication fault code sent by the diagnosis equipment and acquires a bus waveform of the topological network to determine fault types;

the diagnosis equipment acquires a topology network among electronic control units in an automobile, determines key nodes in the topology network, and divides the topology network into a plurality of sub-network segments according to the key nodes;

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

the diagnosis equipment performs fault diagnosis on the network nodes in the sub-network segments to determine the network nodes with faults.

In a fifth aspect, an embodiment of the present invention provides a non-volatile computer-readable storage medium storing computer-executable instructions for causing a diagnostic apparatus to perform the above-described fault localization method of an automobile bus.

In a sixth aspect, an embodiment of the present invention provides a computer program comprising program instructions that, when executed by one or more processors in a diagnostic device, cause the diagnostic device to perform the above-described method of fault localization of an automotive bus.

The embodiment of the invention has the beneficial effects that: in a situation different from the prior art, the method for locating the fault of the automobile bus provided by the embodiment of the invention comprises the following steps: obtaining a topology network among electronic control units in an automobile, wherein the electronic control units are connected through buses; 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 trunk 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 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 disconnection state in the topology network, two network segments which are not communicated with each other exist in the topology network; if a fault exists in one of the two network segments when a certain key node is disconnected, the fault is positioned in the network segment. By determining the key nodes and locating the network section where the fault is located, the embodiment of the invention can improve the efficiency of locating the fault of the automobile.

Drawings

One or more embodiments are illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements, and in which the figures of the drawings are not to be taken in a limiting sense, unless otherwise indicated.

FIG. 1 is a schematic diagram of an automobile detection system according to an embodiment of the present invention;

FIG. 2 is a schematic flow chart of a fault locating method for 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 split controller area network according to an embodiment of the present invention;

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

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

fig. 7 is a schematic diagram of a refinement flow 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 invention;

FIG. 9 is a schematic flow chart of an automobile detection method according to an embodiment of the present invention;

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

Detailed Description

The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent. 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. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

It should be noted that, if not in conflict, the features of the embodiments of the present invention may be combined with each other, which is within the protection scope of the present invention. In addition, while functional block division is performed in a device diagram and logical order is shown in a flowchart, in some cases, the steps shown or described may be performed in a different order than the block division in the device, or in the flowchart. Furthermore, the words "first," "second," "third," and the like as used herein do not limit the order of data and execution, but merely distinguish between identical or similar items that have substantially the same function and effect.

Before explaining the present invention in detail, terms and terminology involved in the embodiments of the present invention are explained, and the terms and terminology involved in the embodiments of the present invention are applicable to the following explanation.

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

(2) The electronic control unit (Electronic Control Unit, ECU), also called "car running computer", "vehicle mounted computer", is a kind of microcomputer controller for car, also called as single chip microcomputer for car. It is composed of microprocessor (CPU), memory (ROM or RAM), input/output interface (I/O), A/D converter (A/D) and shaping and driving large-scale integrated circuits.

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

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

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

(6) The local interconnect network, (Local Interconnect Network, LIN) is a low cost serial communication network for implementing distributed electronic system control in automobiles. The purpose of LIN is to provide auxiliary functions for existing automotive networks, such as CAN-bus, so LIN-bus is an auxiliary bus network. The use of the LIN bus for communication between the intelligent sensor and the brake device CAN provide significant cost savings where the bandwidth and functionality of the CAN bus are not required. Development tools and application software interfaces are defined in the LIN specification in addition to basic protocols and physical layers. LIN communication is based on SCI (UART) data format, using a 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 automotive internal network communication protocol, CAN also provide reliability features that many CAN networks do not have. In particular, the redundant communication capability of FlexRay can realize the complete network configuration replication through hardware and progress monitoring. FlexRay provides a flexible configuration at the same time, supporting various topologies such as bus, star and hybrid topologies. A designer may configure a distributed system by combining two or more topologies of this type. Each FlexRay node comprises a controller and a driver component. The controller component includes a host processor and a communications 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 access bus. The host informs the bus guardian that the communication controller has allocated those time slots. Next, the bus guardian only allows the communications controller to transmit data in these slots and activates the bus driver. If the bus guardian finds that the time sequence has an interval, the connection of the communication channel is disconnected.

It should be noted that, in the embodiment of the present invention, the diagnostic device may be a mobile terminal, and may also be a personal computer (Personal Computer, PC), where the mobile terminal may be a hardware device such as a smart phone, a tablet computer, a personal digital assistant, and the like, which has various operating systems. The fault locating 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 automobile diagnostic system according to an embodiment of the 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 means (supporting CAN communication protocol) for communicating with an automobile. The oscilloscope supports measurement of voltage, current, resistance, frequency and the like, supports a triggering function, and can store waveform data. The application software of the diagnostic apparatus comprises automobile diagnostic software, oscilloscope measurement software, automobile maintenance data or maintenance guide. In the running process of the automobile diagnosis software, an oscilloscope measurement function can be called, data are extracted from oscilloscope application, and the next maintenance analysis is carried out by matching with a maintenance guide.

In the 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 testing (standard OBD interface, 16 PIN), which DLC interface supports SAE J1962/ISO 15031-3 standard, typically PIN6 and PIN14 as diagnostic CAN data interfaces. In 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 probe needs to be connected to the connection point recommended by the diagnostic device 111.

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

In the communication of automobile electronic parts ECU, CAN bus plays a very important role, especially in the power assembly part, and the communication between the ECUs is completed through high speed PT-CAN. The high-speed CAN bus is a broadcasting network, and consists of two data buses CAN-H and CAN-L, and transmits differential signals, wherein any one of the data lines fails, is open or short-circuited, and the whole network communication is invalid. In general, when the automobile CAN bus is overhauled, the more reliable inspection method is to pull out all terminal devices and insert the terminal devices one by one, and simultaneously observe whether faults reappear. If the fault is repeated, the last terminal position with the problem after insertion is the position where the fault occurs. The method is feasible for a miniaturized CAN network, but when the number of terminals on a CAN bus is large, the method brings some problems, namely firstly, the efficiency is low, and when the other is inserted, the novel problems CAN be brought by misinsertion of the terminals and mixed insertion of CAN-H and CAN-L. How to provide an efficient and trouble-free fault point detection scheme is very important for CAN bus fault detection.

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

Specifically, referring to fig. 2, fig. 2 is a flow chart of a fault locating method for 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 (Controller Area Network, CAN), wherein the controller area network comprises a plurality of network nodes, and the network nodes are in communication connection through the CAN bus.

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

step S10: obtaining a topology network among electronic control units in an automobile, wherein the electronic control units are connected through buses;

it will be appreciated that each electronic control unit corresponds to a network node in the topology network, and that a plurality of electronic control units are directly communicatively connected in the topology 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 of CAN-H and CAN-L, and 120 Ω resistors are respectively connected to the two terminals. If the CAN network is normal, the power VCC is disconnected and the resistance R of the whole loop should be measured at the end points of the gateway ECU X1, X2 to be around 60 Ω. If a fault, short or open circuit occurs on the bus, the measured value of the resistance R will vary greatly. Under the abnormal condition of the buses, the waveform on the buses can be analyzed through the oscilloscope in the communication state, and the fault of which bus is open circuit, short circuit to ground, short circuit to power supply or mutual short circuit is judged. After knowing the fault type, it is also necessary to locate the specific location of the fault in the network.

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

as shown in fig. 4, on the CAN bus, there are a lot of network nodes, and it is very challenging to quickly determine the specific location where the fault occurs. In general, some key nodes are selected in a network, the network is divided into a plurality of sub-network segments, firstly, which network segment the fault occurs in is checked, then the network segment with the fault is checked, the fault occurrence range is gradually reduced, and the efficiency of locating the fault position is improved.

As shown in fig. 4, the topology network of the controller area network is composed of 15 total network nodes from Node1 to Node15, wherein four network positions of X01, X02, X03 and X04 divide the controller area network into five sub-network segments, four network positions of X01, X02, X03 and X04 are key nodes in the controller area network, when a network fault occurs, the key nodes are gradually disconnected, and whether the network fault phenomenon disappears is observed to judge in which sub-network segment the network fault occurs, so as to achieve the purpose of reducing the search range. For example, the network fault occurs in the network Node7, and after the key Node X03 is disconnected, the bus communication of the gateway segment is recovered, so as to determine that the network fault occurs in the range of the sub-network segment covered by the key Node X03 (including the sub-network segment 2 and the sub-network segment 3); after the key node X02 is continuously disconnected, the key node X03 is connected, the gateway section fault reappears, and the fault in the sub-network section 2 can be disconnected, so that the network node with the fault can be gradually searched in the sub-network section 2 to remove 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 trunk 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 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 to fig. 5 again, fig. 5 is a detailed flowchart of step S10 in fig. 2;

as shown in fig. 5, this step S20: determining a reference node in the topology 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 longest, and a link between the first terminal node and the second terminal node is a trunk path;

referring to fig. 6 again, fig. 6 is a schematic diagram of a topology diagram 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 longest, so that the network Node11 is determined to be a first terminal Node, the network Node15 is determined to be a second terminal Node, or the network Node15 is determined to be a first terminal Node, and the network Node11 is determined to be a second terminal Node, in the embodiment of the present invention, the network Node11 is taken as the first terminal Node, the network Node15 is taken as the second terminal Node as an example, and the link between the network Node11 and the network Node15 is taken as a backbone path.

Step S22: determining a weight of each network node between the first terminal node and the 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 by links between the network node and the backbone path includes:

As shown in fig. 6, when the link between the network Node1 and the trunk path is not connected with other network nodes, it is determined that the weight of the network Node1 is 1, and the link between the network Node2 and the trunk path is connected with the network Node1, that is, 1 network Node is connected, so that the weight of the network Node2 is determined to be 1+1=2, and the like, the weight of the network Node3 is determined to be 3, the weight of the network Node4 is 4, the weights of the network nodes Node5-10 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 searching step length M, and determining the reference node;

specifically, referring to fig. 7 again, fig. 7 is a schematic diagram of the refinement flow of step S23 in fig. 5;

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

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=1 is initialized.

Step S232: judging whether a sub-node exists in a network node on a trunk path from the first terminal node to the second terminal node;

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, where the network Node on the backbone path from the first terminal Node to the second terminal Node refers to a link directly connected to the backbone path, and a 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.

Step S233 is performed by judging whether a sub-node exists in a network node on a trunk path from the first terminal node to the second terminal node, if yes, the step S233 is performed; 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 may be understood that the second reference node refers to a reference node on a branched path, and specifically, if a sub-node exists in a network node on a backbone path from the first terminal node to the second terminal node, it is determined that at least one branched link exists in the topology network; according to the weight of each network node on a certain branch chain, determining the network node with the weight being integral multiple of the searching step length as a second reference node, and recursively searching each branch chain until all network nodes on all branch chains are traversed.

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

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

Specifically, it is assumed that the search step is M, where M is a positive integer and M is equal to or greater than 2, and preferably the search step is 3 or 4.

It may be understood that the first reference Node refers to a reference Node on a backbone path, a network Node that does not include a child Node is searched from the first terminal Node, and if the search step size is 4, a network Node that does not include a child Node is searched from the first terminal Node11, and each time a network Node passes, a counter count=count+1, that is, a counter count=2 when searching the network Node10, a counter count=3 when searching the network Node9, a counter count=4 when searching the network Node8, and when the reading of the counter is an integer multiple of the search step size, 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 disconnection state in the topology network, two network segments which are not communicated with each other exist in the topology network;

Specifically, the determining the 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 in communication with each other.

Specifically, a search algorithm for determining a key node in the controller area network in an 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, namely searching from the network Node11 to the network Node15 in fig. 6, wherein a counter count=1, and searching a reference Node step length m=4;

(2) If the network Node on the trunk path also has a child Node (for example, node1 has a child Node, and the weight is 1, and the child Node is used as the child Node on the trunk path), the child Node is used as a reference Node and recorded, and the search of the branch is transferred to the step (5);

(3) If the network node on the trunk path has no child node, adding 1 to a counter Count, and if the Count is an integer multiple of M, taking the network node as a reference node;

(4) Searching each network Node on the trunk path until reaching a second terminal Node, namely a network Node15;

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

(6) Searching for a position which can be disconnected in the vicinity of the searched reference node: there is a plug and after disconnection the network is divided into two disconnected networks, the plug location is the critical node.

In the embodiment of the invention, in actual operation, the search step length M of the reference node is 3 or 4, so that the search range between the sections can be reduced, the contraction range in the sections can be reduced, and in the worst case, N/M+M-2 times is positioned, 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 a certain key node is disconnected, locating the fault in the network segment;

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

Specifically, the plurality of key nodes divide the controller local area network into a plurality of sub-network segments, and when a network fault occurs, the sub-network segments with the network fault are determined according to whether the network fault is eliminated or not by disconnecting the key nodes one by one;

specifically, the method includes:

judging whether loop resistance in the controller local area 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 controller area 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 an embodiment of the present invention, the method further includes: and performing fault troubleshooting on the network nodes in the sub-network segments to determine the network nodes with faults.

In the embodiment of the invention, each key node corresponds to at least one subnet segment.

In an embodiment of the present invention, by providing a fault locating method for an automobile bus, the method includes: obtaining a topology network among electronic control units in an automobile, wherein the electronic control units are connected through buses; 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 trunk 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 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 disconnection state in the topology network, two network segments which are not communicated with each other exist in the topology network; if a fault exists in one of the two network segments when a certain key node is disconnected, the fault is positioned in the network segment. By determining the key nodes and locating the network section where the fault is located, the embodiment of the invention can improve the efficiency of locating the fault of the automobile.

Referring to fig. 8 again, fig. 8 is a schematic diagram of an automobile diagnosis bus and an online CAN bus according to an embodiment of the present invention;

as shown in fig. 8, the DLC interface is connected to the gateway via a diagnostic bus, which comprises a CAN bus and a LIN bus, wherein the gateway is also 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 most vehicle types, the diagnostic bus CAN access the internal CAN bus 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, measurements CAN be taken at X3001 and X3002 of the gateway.

In the embodiment of the invention, the automobile detection system comprises diagnostic equipment, an oscilloscope and a universal meter. 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 triggering function, and can store waveform data. The application software of the diagnostic apparatus 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, wherein in the operation of the diagnosis software, an oscilloscope measurement function can be called, data are extracted from the oscilloscope application, and the next maintenance analysis is 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 the whole functions of the diagnostic device and the oscilloscope.

During the test, the car is connected to the diagnostic device via a DLC interface (standard OBD interface, 16 PIN), which supports SAE J1962/ISO 15031-3 standard, typically PIN6 and PIN14 as diagnostic CAN data interfaces. In diagnostic devices, 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 probe needs to be connected to the connection point recommended by the diagnostic device.

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

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

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

specifically, the vehicle detection method is applied to a vehicle including a vehicle control unit system (ECU system) to which the diagnostic apparatus is communicatively connected, for example: scanning the automobile control unit system through the DLC interface to obtain a communication fault code, wherein the diagnosis equipment scans the automobile ECU system through the DLC interface to find that the communication fault code exists or the ECU system cannot be connected, wherein the diagnosis equipment comprises diagnosis software, and the diagnosis software starts a maintenance guide to guide a user to perform communication fault detection;

Step S92: the oscilloscope acquires a communication fault code sent by the diagnosis equipment and acquires a bus waveform of the topological network to determine fault types;

specifically, the maintenance guide prompts a user to start a measuring tool, captures waveforms on a CAN communication line through an oscilloscope, and judges that CAN faults belong to fault categories such as ground short circuit, power short circuit, wire short circuit, bus open circuit, abnormal terminal resistance, overlong branch line and the like through waveform comparison analysis;

step S93: the diagnosis equipment acquires a topology network among electronic control units in an automobile, determines key nodes in the topology network, and divides the topology 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 local area network, a path between the first terminal node and the second terminal node is longest, and a link between the first terminal node and the second terminal node is a trunk path; determining a weight of each network node between the first terminal node and the 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 the network fault occurs, the diagnosis equipment disconnects the key nodes one by one, and determines a sub-network segment with the network fault 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 are required to be verified at present through a topological graph of the controller local area network, namely a topological network, prompts a user to disconnect the key nodes and then analyzes bus waveforms, and determines a sub-network segment with faults through the fact that the user disconnects the key nodes, the diagnosis equipment disconnects the key nodes and then subsequently connects the disconnected key nodes.

Step S95: the diagnosis equipment performs fault diagnosis on the network nodes in the sub-network segments to determine the network nodes with faults.

Specifically, by inspecting each network node in the sub-network segment, the failed network node is determined.

Specifically, the automobile detection method comprises the following steps:

(1) The diagnosis equipment scans the ECU system of the automobile through the DLC interface, discovers that a communication fault code exists or the ECU system cannot be connected, and diagnosis software starts maintenance guide to guide a user to perform communication fault detection;

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

(3) The maintenance guide prompts a user to start a measuring tool, captures waveforms on the CAN communication line through the oscilloscope, and judges that the CAN faults belong to fault categories such as ground short circuit, power short circuit, wire short circuit, bus open circuit, abnormal terminal resistance, overlong branch lines and the like through waveform comparison analysis;

(4) The maintenance guide calculates key nodes of the CAN bus and key points which are most required to be verified at present through the CAN topological graph, and prompts a user to analyze bus waveforms 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 disconnected network, if the waveform is normal, the step (7) is carried out, and if the waveform is not normal, the step (9) is carried out;

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

(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. Judging that the oscillograph has abnormal waveform, if the oscillograph has abnormal waveform, calculating the next key node to be disconnected, if the oscillograph has abnormal waveform, calculating the fault in the X section, and if the oscillograph has abnormal waveform, calculating the next key node to be disconnected until a 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, an automobile detection method is provided, and is applied to the automobile detection system described in the above embodiment, where the method includes: the diagnosis equipment scans the automobile control unit system to acquire a communication fault code; the oscilloscope acquires a communication fault code sent by the diagnosis equipment and acquires a bus waveform of the topological network to determine fault types; the diagnosis equipment acquires a topology network among electronic control units in an automobile, determines key nodes in the topology network, and divides the topology network into a plurality of sub-network segments according to the key nodes; when the network fault occurs, the diagnosis equipment disconnects the key nodes one by one, and determines a sub-network segment with the network fault according to whether the bus waveform of the topology network acquired by the oscilloscope is recovered to be normal or not; the diagnosis equipment performs fault diagnosis on the network nodes in the sub-network segments to determine the network nodes with faults. By determining the key nodes, determining the sub-network segments with network faults, and performing fault troubleshooting on the network nodes in the sub-network segments to determine the network nodes with faults, the embodiment of the invention can improve the efficiency of positioning the automobile faults.

Referring to fig. 10, fig. 10 is a schematic hardware structure of a diagnostic device 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 device 100 further comprises a camera, which comprises 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 source 1011, and the like. It will be appreciated by those skilled in the art that the configuration of the diagnostic device shown in fig. 10 does not constitute a limitation of the diagnostic device, and the diagnostic device may include more or less components than illustrated, or certain components may be combined, or a different arrangement of components. In the embodiment of the invention, the diagnosis equipment comprises, 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.

A processor 1010, configured to obtain a topology network between electronic control units in an automobile, where each electronic control unit is connected by 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 trunk 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 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 disconnection state in the topology network, two network segments which are not communicated with each other exist in the topology network; if a fault exists in one of the two network segments when a certain key node is disconnected, the fault is positioned in the network segment.

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

It should be understood that, in the embodiment of the present invention, the radio frequency unit 101 may be configured to receive and send information or signals during a call, specifically, receive downlink data from a base station, and then process the received downlink data with the processor 1010; and, the uplink data is transmitted to the base station. Typically, the 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 may also communicate with networks and other devices through a wireless communication system.

Diagnostic device 100 provides wireless broadband internet access to users, such as helping users send and receive e-mail, browse web pages, and access streaming media, etc., via network module 102.

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 (e.g., a call signal reception sound, a message reception sound, etc.) related to a specific function performed by the diagnostic apparatus 100. The audio output unit 103 includes a speaker, a buzzer, a receiver, and the like.

The input unit 104 is used for receiving an audio or video signal. The input unit 104 may include a graphics processor (Graphics Processing Unit, GPU) 1041 and a microphone 1042, the graphics processor 1041 processing 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 graphics 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. Microphone 1042 may receive sound and be capable of processing such sound into audio data. The processed audio data may be converted into a format output that can be transmitted to the mobile communication base station via the radio frequency unit 101 in the case of a telephone call mode.

The diagnostic device 100 also includes at least one sensor 105, such as a light sensor, a motion sensor, 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 acceleration in all directions (generally three axes), and can detect the gravity and direction when stationary, and can be used for identifying the gesture of diagnostic equipment (such as horizontal and vertical screen switching, related games, magnetometer gesture calibration), vibration identification related functions (such as pedometer and knocking), and the like; the sensor 105 may further include a fingerprint sensor, a pressure sensor, an iris sensor, a molecular sensor, a gyroscope, a barometer, a hygrometer, a thermometer, an infrared sensor, etc., which are not described 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 (Liquid Crystal Display, LCD), an Organic Light-Emitting Diode (OLED), or the like.

The user input unit 107 is operable to receive input numeric or character information and to generate key signal inputs related to user settings and function control of the diagnostic device. Specifically, the user input unit 107 includes a touch panel 1071 and other input devices 1072. The touch panel 1071, also referred to as a touch screen, may collect touch operations thereon or thereabout by a user (e.g., operations of the user on the touch panel 1071 or thereabout using any suitable object or accessory such as a finger, stylus, etc.). The touch panel 1071 may include two parts of a touch detection device and a touch controller. The touch detection device detects the touch azimuth 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 detection 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. Further, the touch panel 1071 may be implemented in various types such as resistive, capacitive, infrared, and surface acoustic wave. The user input unit 107 may include other input devices 1072 in addition to the touch panel 1071. In particular, 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 thereabout, the touch panel 1071 is transferred to the processor 1010 to determine the type of touch event, and then the processor 1010 provides a corresponding visual output on the display panel 1061 according to the type of touch event. Although in fig. 10, the touch panel 1071 and the display panel 1061 are two independent components for implementing the input and output functions of the diagnostic device, in some embodiments, the touch panel 1071 may be integrated with the display panel 1061 to implement the input and output functions of the diagnostic device, which is not limited herein.

The interface unit 108 is an interface to which an external device is connected to the diagnostic apparatus 100. For example, the external devices may include a wired or wireless headset port, an external power (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 the external device.

Memory 109 may be used to store software programs as well as various data. The memory 109 may mainly include a storage program area that may store an application program 1091 (such as a sound playing function, an image playing function, etc.) required for at least one function, an operating system 1092, etc.; the storage data area may store data (such as audio data, phonebook, etc.) created according to the use of the handset, etc. In addition, 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 device, connects various parts of the entire diagnostic device using various interfaces and lines, and performs various functions and processes of the diagnostic device 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 device. The processor 1010 may include one or more processing units; preferably, the processor 1010 may integrate an application processor that primarily handles operating systems, user interfaces, applications, etc., with a modem processor that primarily handles wireless communications. It will be appreciated that the modem processor described above may not be integrated into the processor 1010.

The diagnostic device 100 may also include a power supply 1011 (e.g., a battery) for powering the various components, and preferably the power supply 1011 may be logically connected to the processor 1010 via a power management system whereby charge, discharge, and power consumption management functions are performed by the power management system.

In addition, the diagnostic device 100 includes some functional modules, which are not shown, and will not be described in detail herein.

Preferably, the embodiment of the present invention further provides a diagnostic device, 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 when executed by the processor 1010 implements the respective processes of the foregoing fault location method embodiment, and the same technical effects can be achieved, and for avoiding repetition, a detailed description is omitted herein.

The embodiment of the invention also provides a computer readable storage medium, on which a computer program is stored, which when executed by one or more processors, implements the processes of the above-mentioned fault locating method embodiment, and can achieve the same technical effects, so that repetition is avoided, and no further description is given here. Wherein the computer readable storage medium is selected from Read-Only Memory (ROM), random access Memory (Random Access Memory, RAM), magnetic disk or 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 one … …" 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, in which the unit modules illustrated as separate components may or may not be physically separate, and the components shown as unit modules may or may not be physical units, may be located in one place, or may be distributed over multiple network module units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

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 several instructions for causing a terminal (which may be a mobile terminal, a personal computer, a server, or a network device, etc.) to perform 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 in connection with the accompanying drawings are only for illustrating the technical aspects of the present application, and the present application is not limited to the above-described embodiments, which are only illustrative, but not restrictive; the technical features of the above embodiments or in the different embodiments may also be combined within the idea of the application, the steps may be implemented in any order, and there are many other variations of the different aspects of the application as described above, which are not provided in detail for the sake of brevity; although the application 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 scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the application.

Claims

1. A method for locating a fault in an automotive bus, the method comprising:

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

the determining a reference node in the topology network comprises:

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

the searching from the first terminal node to the second terminal node according to the searching step length M, and determining the reference node comprises the following steps:

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

2. The method of claim 1, wherein the determining the weight of each network node between the first and second terminal nodes comprises:

3. The method of claim 2, 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:

4. The method according to claim 1, wherein said determining a second reference node based on the weight of the network node of the at least one branch link comprises:

5. The method of claim 1, wherein determining a key node based on the location of the reference node comprises:

6. The method according to claim 1, wherein the method further comprises:

7. The method according to claim 6, further comprising determining whether a network failure has been eliminated, comprising:

8. A diagnostic device, characterized in that the diagnostic device comprises: the communication interface is used for being connected with the automobile in a communication mode, the automobile comprises a topology network among electronic control units, the topology network comprises a plurality of network nodes, and the main controller comprises:

at least one processor; and

a memory communicatively coupled to the at least one processor; wherein,

the memory stores instructions executable by the at least one processor to enable the at least one processor to perform the fault localization method of the automotive bus of any one of claims 1-7.

9. An automobile detection system for an automobile, the automobile comprising an automobile control unit system comprising a plurality of automobile control units, the automobile detection system comprising:

the diagnostic device of claim 8, which is communicatively coupled to the automotive control unit system;

10. A method of vehicle detection as claimed in claim 9, wherein the method comprises: