CN110758285B - Vehicle electrical and CAN communication connection establishing device and method - Google Patents

Abstract

The invention relates to the field of vehicle electrical connection and communication, and discloses a vehicle electrical and CAN communication connection establishing device and a method, which comprises a tractor braking unit and a trailer electronic braking unit, wherein the tractor electronic braking unit and the trailer electronic braking unit are electrically connected through an ISO 7638 joint, and both the tractor electronic braking unit and the trailer electronic braking unit are provided with a plurality of CAN transceivers, so that CAN communication between adjacent vehicles CAN be realized. And the technical problem that normal CAN communication CAN not be carried out between the nodes of the transceivers of different physical layer levels is solved, and the compatibility of CAN communication between the tractor and the trailer as well as between trailer trains is guaranteed.

Description

Vehicle electrical and CAN communication connection establishing device and method

Technical Field

The invention relates to the field of electrical connection and CAN communication connection between vehicles, in particular to a device and a method for establishing electrical and CAN communication connection of a vehicle.

Background

The electric connection between a tractor and a trailer equipped with an Electronic Brake System (EBS) and a trailer train adopts a standard joint conforming to ISO 7638, and the joint contains 7 pins which are respectively a battery anode, an ignition switch anode, a power ground, an alarm indicator lamp anode, an alarm indicator lamp ground, a CAN _ H pin and a CAN _ L pin. The CAN _ H pin and the CAN _ L pin are buses for transmitting information between the tractor and the trailer train, and generally conform to the standard of ISO 11992, which defines the physical layer signal standard of the CAN bus and the specifications of network node initialization, network management and network message forwarding. In the conventional art known in the prior art, the electrical connection and network management between the tractor and the trailer train is implemented using a dedicated central electronic unit (gateway) for the trailer, as shown in fig. 1.

The tractor 1 is equipped with traditional tractor electronic brake unit (EBS) 7, and traditional tractor electronic brake unit 7 links to each other with tractor gateway 8, and tractor gateway 8 sends power, fault indicator lamp, CAN communication interface to the central electronic unit of trailer (gateway) 6 in first trailer 2 through ISO 7638 joint 5, and the central electronic unit of trailer (gateway) 6 then divides two tunnel electrical interface, and one road is connected to local (this trailer) traditional trailer electronic brake unit (EBS) 9, and the other road is connected to follow-up second trailer 3 through subsequent ISO 7638 joint. The central electronic unit (gateway) of the second trailer 3 then sends the electrical connections in the same way to the local conventional electronic brake unit (EBS) 8 of the second trailer 3 and to the ISO 7638 connector 5 of the subsequent trailer, respectively, and so on until the last trailer. The central electronic unit (gateway) 6 of the trailer plays the roles of an electrical relay, a junction box and a gateway, forms a local network segment with a local traditional trailer electronic brake unit (EBS) 9, and the functions of network management, network initialization, network message forwarding and the like are all realized by the central electronic unit (gateway) 6 of the trailer.

In the above conventional electrical connection manner, the conventional tractor electronic brake unit (EBS) 7 and the conventional trailer electronic brake unit (EBS) 9 only need to be responsible for the braking function of the vehicle, and do not need to consider the functions in the network management and the electrical distribution, but such an electrical connection manner inevitably causes a lot of vehicle wiring harnesses, and an electronic unit (gateway) is added to be specifically responsible for the electrical distribution and the network management, which not only increases the cost, but also cannot be flexibly arranged.

In addition, ISO 11992 defines CAN physical layer signal levels of 24V and 12V for tractors and trailers of 24V and 12V systems, respectively. However, the signal level of the CAN communication physical layer defined in ISO 11898 and SAE J1939 standards is 5V, and 5V CAN communication is widely applied to communication of various passenger vehicles, commercial vehicles and special vehicles, and is irrelevant to whether the vehicle adopts a 24V system or a 12V system. At present, almost all CAN communication transceiver chips adopt a 5V level for communication, and transceiver chips of 24V and 12V communication levels are only used in a very small amount and are in monopoly and non-open states. Normal CAN communication cannot be performed between nodes of transceivers adopting different physical layer levels, which causes a great compatibility problem for CAN communication between a tractor and a trailer as well as between trailer trains.

Furthermore, Wabco in CN109479186A discloses a method for constructing a wireless network between a tractor and a trailer, but still relies on the connection construction of the wireless network after the normal connection of the CAN bus between the tractor and the trailer, and does not solve the problem of CAN communication compatibility between the tractor and the trailer and between trailer trains.

Disclosure of Invention

In order to avoid the above disadvantages caused by the traditional electrical connection mode between the tractor and the trailer and between the trailer train and solve the compatibility problem between different CAN communication physical levels, the invention provides a vehicle electrical and CAN communication connection establishing device and method.

In order to solve the technical problem, the invention is solved by the following technical scheme:

the vehicle electric and CAN communication connection establishing device comprises a tractor electric brake unit and a trailer electric brake unit, wherein the tractor electric brake unit and the trailer electric brake unit are electrically connected through an ISO 7638 joint; the tractor electronic brake unit is provided with a first socket and a second socket, the tractor electronic brake unit comprises a tractor network management unit and a tractor brake control unit, the first socket is used for supplying power to the tractor network management unit and the tractor brake control unit through pin combination and is connected to the second socket, the second socket is connected to a plug, a CAN _ H pin and a CAN _ L pin are arranged in the second socket, a tractor CAN transceiver unit is arranged in the tractor electronic brake unit, the CAN _ H pin and the CAN _ L pin are both connected to the tractor CAN transceiver unit, the tractor CAN transceiver unit is enabled or disabled through an enabling pin on the tractor network management unit, the tractor CAN transceiver unit is in communication connection with the tractor network management unit, and the tractor network management unit is connected with the CAN _ H pin or/and the CAN _ L pin through the CAN transceiver unit to perform CAN communication; level signals of the CAN _ H pin or/and level signals of the CAN _ L pin enter a CAN bus level signal acquisition port of the tractor, and are acquired and subsequently processed by a tractor network management unit; the trailer electronic brake unit comprises a previous socket which CAN be connected to an ISO 7638 connector between the trailer electronic brake unit and a previous vehicle, the trailer electronic brake unit further comprises a trailer network management unit and a trailer brake control unit, a previous CAN _ H pin and a previous CAN _ L pin are arranged in the previous socket, the previous CAN _ H pin and the previous CAN _ L pin are both connected to the previous CAN transceiver unit, and the trailer network management unit enables or disables the previous CAN transceiver unit through an enabling pin; the trailer network management unit is provided with a previous CAN channel, is connected to a previous CAN transceiver unit through the previous CAN channel, is connected with a previous CAN _ H pin or/and a previous CAN _ L pin through the previous CAN transceiver unit and carries out CAN communication; the previous CAN _ H pin or/and the previous CAN _ L pin level signal enter a trailer previous CAN bus level signal acquisition port, and the trailer network management unit performs acquisition and subsequent processing; at least one CAN transceiver with the same level exists in the tractor CAN transceiver unit and the previous CAN transceiver unit.

Preferably, the trailer network management unit further comprises a subsequent socket, the subsequent socket is connected to the subsequent socket, the subsequent socket CAN be connected to a joint between subsequent trailers, a subsequent CAN _ H pin and a subsequent CAN _ L pin are arranged in the subsequent socket, the subsequent CAN _ H pin and the subsequent CAN _ L pin are both connected to the subsequent CAN transceiver unit, and the trailer network management unit enables or disables the subsequent CAN transceiver unit through an enabling pin respectively; the trailer network management unit has a subsequent CAN channel and is connected to the subsequent CAN transceiver units via the subsequent CAN channel and is connected to and CAN-communicates with the subsequent CAN _ H pin or/and the subsequent CAN _ L pin via one of the subsequent CAN transceiver units.

Preferably, the tractor electronic brake unit further comprises a CAN bus level signal processing circuit, the CAN bus level signal processing circuit is connected with a CAN _ H pin or/and a CAN _ L pin and processes a voltage signal of the CAN _ H pin or a voltage signal of the CAN _ L pin, and the processed level signal enters a tractor CAN bus level signal acquisition port; the tractor network management unit and the brake control unit carry out data interaction through data communication; the previous CAN _ H pin or/and the previous CAN _ L pin are/is also connected to a trailer previous CAN bus level signal processing circuit, the processing circuit processes the voltage signal of the previous CAN _ H pin or/and the previous CAN _ L pin D, the processed level signal enters a trailer previous CAN bus level signal acquisition port, and the trailer network management unit performs acquisition and subsequent processing; the trailer network management unit and the trailer brake control unit carry out data interaction through data communication, a subsequent CAN _ H pin or/and a subsequent CAN _ L pin are/is also connected to a subsequent CAN bus level signal processing circuit of the trailer, the processing circuit processes a voltage signal of the subsequent CAN _ H pin, the processed level signal enters a subsequent CAN bus level signal acquisition port of the trailer, and the trailer network management unit carries out acquisition and subsequent processing; the trailer network management unit and the brake control unit also have a data channel for exchanging data.

Preferably, the number of the trailer electronic brake units is at least two, the adjacent trailer electronic brake units are electrically connected through an ISO 7638 connector, the adjacent trailer electronic brake units are in CAN communication with the previous CAN transceiver unit of the next trailer electronic brake unit through the subsequent CAN transceiver unit of the previous trailer electronic brake unit, and at least one CAN transceiver with the same level exists between the subsequent CAN transceiver unit of the previous trailer electronic brake unit and the previous CAN transceiver unit of the next trailer electronic brake unit.

Preferably, the tractor CAN transceiver unit comprises one or two of a 24V CAN transceiver, a 12V CAN transceiver and a 5V CAN transceiver or simultaneously comprises the 24V CAN transceiver, the 12V CAN transceiver and the 5V CAN transceiver; the preceding CAN transceiver unit comprises one or two of a 24V CAN transceiver, a 12V CAN transceiver and a 5V CAN transceiver or simultaneously comprises a 24V CAN transceiver, a 12V CAN transceiver and a 5V CAN transceiver; when the types of the CAN transceivers in the tractor CAN transceiver units are two or three, the tractor network management unit CAN enable/disable each CAN transceiver independently, and the tractor network management unit is connected with a CAN _ H pin or/and a CAN _ L pin through one of the two or three CAN transceivers to carry out CAN communication; when the types of the CAN transceivers in the previous CAN transceiver units are two or three, the trailer network management unit CAN enable/disable each CAN transceiver independently, and the trailer network management unit is connected with the CAN _ H pin or/and the CAN _ L pin through one of the two or three CAN transceivers to carry out CAN communication.

Preferably, the subsequent CAN transceiver unit comprises one or two of a 24V CAN transceiver, a 12V CAN transceiver and a 5V CAN transceiver or simultaneously comprises the 24V CAN transceiver, the 12V CAN transceiver and the 5V CAN transceiver; when the types of the CAN transceivers in the subsequent CAN transceiver units are two or three, the trailer network management unit CAN enable/disable each CAN transceiver independently, and the trailer network management unit is connected with the CAN _ H pin or/and the CAN _ L pin through one of the two or three CAN transceivers to carry out CAN communication.

Preferably, the trailer network management unit and the trailer brake control unit are integrated in one processing unit, or/and the tractor network management unit and the tractor brake control unit are integrated in one processing unit.

Preferably, the first socket comprises a pin assembly, the second socket comprises a pin assembly, the pin assembly of the first socket supplies power to the tractor network management unit and the trailer brake control unit, and the pin assembly of the first socket is connected with the pin assembly of the second socket; the pin combination of the previous socket supplies power for the trailer network management unit and the trailer brake control unit and is connected to the pin combination of the subsequent socket, and the pin combination of the previous socket is connected with the pin combination of the subsequent socket.

A vehicle electrical and CAN communication connection establishing method is characterized in that: including the vehicle electrical and CAN communication connection establishing apparatus of claim 4, the CAN establishing connection process between the tractor and the trailer and between the trailer and the trailer comprising the steps of:

the method comprises the following steps that firstly, a system is electrified, and the tractor electronic brake unit and the trailer electronic brake unit complete electrification self-check;

step two, enabling 5V CAN transceivers in all CAN transceiver units connected with the ISO 7638 joint by the tractor electronic brake unit and all trailer electronic brake units, forbidding CAN transceivers of other levels, and entering a CAN bus monitoring mode;

step three, the tractor electronic brake unit detects the signal level received by the tractor CAN bus, and the trailer electronic brake unit detects the voltage of the previous CAN signal of the trailer electronic brake unit through the previous CAN bus level signal acquisition port and detects the voltage of the subsequent CAN signal of the trailer electronic brake unit through the subsequent CAN bus level signal acquisition port;

step four, the tractor electronic brake unit and all trailer electronic brake units judge whether the CAN signal voltage received by the CAN bus interface is within the communication standard range of 5V CAN, if so, the corresponding CAN channel adopts 5V CAN communication and enters a subsequent normal communication mode; otherwise, entering the next step, and judging whether the communication is in the 24V CAN communication standard range;

step five, the tractor electronic brake unit and all trailer electronic brake units judge whether the CAN signal voltage received by the CAN bus interface is in a 24V communication standard range, if so, the corresponding CAN channel adopts 24V CAN communication and enters the next step to switch the corresponding channel to 24V CAN communication; otherwise, entering a step three to continuously detect the CAN signal voltage;

step six, the tractor electronic brake unit and the trailer electronic brake unit respectively forbid the 5V CAN transceivers of the corresponding CAN channels, and enable the 24V CAN transceivers of the corresponding CAN channels, so that the corresponding CAN channels are switched to 24V CAN communication;

and step seven, after the CAN channel is switched to the correct bus communication level, the channel enters a normal communication mode: according to the specification requirements of ISO 11992, network initialization and message forwarding are performed, and application messages are normally received/sent.

Preferably, in the fifth step, when the tractor electronic brake unit and all trailer electronic brake units judge that the CAN signal voltage received by the CAN bus interface is not in the 5V CAN communication standard range or in the 24V communication standard range, judging whether the CAN signal voltage is in the 12V CAN communication range, if so, adopting 12V CAN communication for the corresponding CAN channel and entering the next step to switch the corresponding channel to 12V CAN communication, and respectively forbidding the 5V CAN transceivers of the corresponding CAN channels by the tractor electronic brake unit and the trailer electronic brake unit to enable the 12V CAN transceivers of the corresponding CAN channels, so as to switch the corresponding CAN channels to 12V CAN communication; if not, the step three is entered to continue to detect the CAN signal voltage.

Due to the adoption of the technical scheme, the electric distribution and gateway functions are integrated by the tractor electronic brake unit and the trailer electronic brake unit, so that a large number of wire harnesses are saved for the whole vehicle, a special electronic unit is omitted, and the circuit arrangement and connection are more flexible and compact. And the technical problem that normal CAN communication CAN not be carried out between the nodes of the transceivers of different physical layer levels is solved, and the compatibility of CAN communication between the tractor and the trailer as well as between trailer trains is guaranteed.

Drawings

Fig. 1 is a schematic diagram of a tractor and trailer connection of the background art.

Fig. 2 is a schematic view of the coupling of the tractor and trailer.

Fig. 3 is a schematic view of the tractor electric brake unit.

Fig. 4 is a schematic view of the trailer electric brake unit.

Fig. 5 is a diagram of a communication establishment procedure.

Graph marking table

1. Tractor vehicle

2. First trailer

3. Second trailer

4. Third trailer

5. ISO 7638 joint

6. Trailer central electronic unit (gateway)

7. Electronic brake unit of traditional tractor (EBS)

8. Tractor gateway

9. Electronic brake unit of traditional trailer (EBS)

10. Tractor electronic brake unit (EBS)

1001. Tractor common socket

1002. Power supply and alarm indicator lamp pin combination of tractor common socket

1003. Tractor network management unit

1004. Tractor brake control unit

1005. Data exchange channel between tractor network management unit and brake control unit

1006. Tractor ISO 7638 socket

1007. Power supply and alarm indicator lamp pin combination of tractor ISO 7638 socket

1008. CAN _ H pin of ISO 7638 socket of tractor

1009. CAN _ L pin of tractor ISO 7638 socket

1010. Tractor 24V CAN transceiver

1011. Tractor 5V CAN transceiver

1012. Tractor CAN bus level signal processing circuit

1013. CAN bus level signal acquisition port of tractor

1014. Tractor 5V CAN transceiver enabling pin

1015. Tractor 24V CAN transceiver enabling pin

1016. CAN transmitting pin of tractor

1017. CAN receiving pin of tractor

1018. CAN channel of tractor

11. Trailer electronic brake unit (EBS)

1101. Trailer ISO 7638 front socket

1102. Power supply and alarm indicator lamp pin combination of trailer ISO 7638 preceding socket

1103. CAN _ H pin of trailer ISO 7638 preceding socket

1104. CAN _ L pin of trailer ISO 7638 preceding socket

1105. Trailer ISO 7638 subsequent socket

1106. Power supply and alarm indicator lamp pin combination of trailer ISO 7638 subsequent socket

1107. CAN _ H pin of trailer ISO 7638 subsequent socket

1108. CAN _ L pin of trailer ISO 7638 subsequent socket

1109. Data channel between trailer network management unit and brake control unit

1110. Trailer network management unit

1111. Trailer front-end CAN channel

1112. Trailer subsequent CAN channel

1113. Trailer front-end CAN bus level signal processing circuit

1114. Trailer front-end CAN bus level acquisition port

1115. Trailer front-end 5V CAN transceiver enabling pin

1116. Trailer front 24V CAN transceiver enabling pin

1117. Trailer front-end 24V CAN transceiver

1118. Trailer front-end CAN transmitting pin

1119. Trailer front-end CAN receiving pin

1120. Trailer front-end 5V CAN transceiver

1121. Subsequent CAN bus level signal processing circuit of trailer

1122. Trailer follow-up CAN bus level acquisition port

1123. Trailer subsequent 24V CAN transceiver

1124. Trailer subsequent 24V CAN transceiver enabling pin

1125. Trailer follow-up 5V CAN transceiver

1126. Trailer follow-up 5V CAN transceiver enabling pin

1127. Trailer subsequent CAN transmitting pin

1128. Trailer subsequent CAN receiving pin

1129. A trailer brake control unit.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples.

Example 1

The present embodiment describes the core idea of the present invention by taking a typical "tractor + semi-trailer train" compatible with 24V and 5V CAN communication as an example, but it does not represent that the present invention is limited to the described vehicle model and application scenario, and those skilled in the art should easily apply the core idea of the present invention to other various vehicle models and scenarios and perform corresponding flexible processing according to the description herein.

Fig. 2 shows a tractor-trailer combination, the components and interfaces not relevant to the core idea of the invention not being shown. The tractor 1 is equipped with a tractor electronic brake unit (EBS) 10 and is fed from a second socket of the tractor electronic brake unit (EBS) 10, which is an ISO 7638 socket 1006, directly leading out an electrical interface to a connection between the tractor 1 and the first trailer 2, which is an ISO 7638 connection 5, and the electronic brake unit (EBS) 11 of the first trailer 2 is connected to the ISO 7638 connection 5 through a preceding socket 1101 (preceding socket) of which is ISO 7638, so as to establish an electrical connection with the tractor 1, and then is branched off from a following socket 1105 (following socket) of which is ISO 7638 to be fed to the following ISO 7638 connection 5. Similarly, the trailer electronic brake unit (EBS) 11 of the second trailer 3 obtains an electrical connection with the first trailer 2 by connecting its ISO 7638 socket 1101 with the ISO 7638 connector 5, and then branches off a electrical connection from its ISO 7638 socket 1105 to the subsequent ISO 7638 connector 5 and establishes an electrical connection with the ISO 7638 socket 1101 of the trailer electronic brake unit (EBS) 11 of the third trailer 4. The cycle is repeated until the last trailer. The tractor electronic brake unit (EBS) 10 and the trailer electronic brake unit (EBS) 11 integrate the functions of electrical distribution and gateway, saving a large number of harnesses for the entire vehicle and a dedicated electronic unit, and making the wiring layout and connection more flexible and compact.

Fig. 3 shows an overview of the tractor electronic brake unit (EBS) 10, components and interfaces not relevant to the core concept of the invention not being shown. The tractor electronic brake unit (EBS) 10 has one or more first sockets 1001 as shown in the figure for connecting a tractor power supply, internal CAN communication, input/output channels, etc., and the socket 1001 contains a power and alarm indicator pin combination 1002 of a tractor common socket related to the present invention, which supplies power to a tractor network management unit 1018 and a tractor brake control unit 1004 and is connected to a power and alarm indicator pin combination 1007 of a tractor ISO 7638 socket 1006 (second socket). In this example, pin combination 1002 is directly connected to pin combination 1007, and those skilled in the art will recognize that pin combination 1002 may be connected to pin combination 1007 after any necessary processing. The tractor ISO 7638 socket 1006 may be a stand-alone dedicated socket, or may be integrated as a portion of a pin into a larger socket or distributed among multiple sockets, all without affecting the core concepts of the present invention. A tractor CAN transceiver unit is arranged in the tractor electronic brake unit 10, the CAN transceiver unit in this embodiment comprises a 24V CAN transceiver 1010 and a 5V CAN transceiver 1011, the tractor ISO 7638 socket 1006 is connected to the ISO 7638 joint 5 between the tractor 1 and the first trailer 2, and a CAN _ H pin 1008 and a CAN _ L pin 1009 are arranged in the tractor ISO 7638 socket 1006, and the two CAN pins are connected to the tractor 24V CAN transceiver 1010 and the 5V CAN transceiver 1011 simultaneously. Tractor network management unit 1018 has CAN transceiver enable pins 1015 and 1014 for enabling/disabling tractor 24V CAN transceiver 1010 and 5V CAN transceiver 1011, respectively. The tractor network management unit 1018 has a CAN channel 1018 with a CAN receive pin 1017 and a transmit pin 1016 connected to both the 24V CAN transceiver 1010 and the 5V CAN transceiver 1011, and CAN communicate with the CAN bus (CAN _ H pin 1008 and CAN _ L pin 1009) via one of the two CAN transceivers. The CAN _ H pin 1008 of the tractor is further connected to a CAN bus level signal processing circuit 1012 of the tractor, which performs necessary processing on the voltage signal of the CAN _ H pin, such as isolation, voltage division, filtering, and the like, and the specific processing method of the present invention is not limited thereto, and the processed level signal enters a CAN bus level signal acquisition port 1013 of the tractor, and is acquired and subsequently processed by a tractor network management unit 1018. There is also a data channel 1005 between the tractor network management unit 1003 and the brake control unit 1004 for exchanging data. Furthermore, the tractor network management unit 1003 and the brake control unit 1004 may also be integrated in one processing unit.

Similarly, fig. 4 shows an overview of the trailer electronic brake unit (EBS) 11, without showing the components and interfaces that are not relevant to the core concept of the invention. The trailer electric brake unit (EBS) 11 has an ISO 7638 preceding socket 1101 for connection to the ISO 7638 plug 5 of the tractor 1 or a preceding trailer, the preceding socket 1101 may be a stand-alone dedicated socket, or may be integrated as a part of a pin into a larger socket or distributed to a plurality of sockets, without affecting the core idea of the present invention, and the preceding socket 1101 includes a power and alarm indicator pin combination 1102 for powering the trailer network management unit 1110 and the trailer brake control unit 1129, and connected to the power and alarm indicator pin combination 1106 of the trailer ISO 7638 subsequent socket 1105. A preceding CAN transceiver unit and a subsequent CAN transceiver unit are arranged in the trailer electronic brake unit 11, and the preceding CAN transceiver unit in the embodiment comprises a preceding 24V CAN transceiver 1117 and a preceding 5V CAN transceiver 1120; the subsequent CAN transceiver units include a subsequent 24V CAN transceiver 1123 and a subsequent 5V CAN transceiver 1125. While the pin combination 1102 is shown directly connected to the pin combination 1106, those skilled in the art will recognize that the pin combination 1102 may be connected to the pin combination 1106 after any processing is necessary. Also within the trailer ISO 7638 preceding socket 1101 is a preceding CAN _ H pin 1103 and a preceding CAN _ L pin 1104, both of which are connected to a preceding 24V CAN transceiver 1117 and a preceding 5V CAN transceiver 1120. The trailer network management unit 1110 has a preceding 24V CAN transceiver enable pin 1116 and a preceding 5V CAN transceiver enable pin 1115 for enabling/disabling the preceding 24V CAN transceiver 1117 and the preceding 5V CAN transceiver 1120, respectively. The trailer network management unit 1110 has a preceding CAN channel 1111 with a preceding CAN receive pin 1119 and a preceding CAN transmit pin 1118 connected to both a preceding 24V CAN transceiver 1117 and a preceding 5V CAN transceiver 1120, which CAN be connected to a preceding CAN bus (a preceding CAN _ H pin 1103 and a preceding CAN _ L pin 1104) and CAN communicate via one of the two CAN transceivers. The preceding CAN _ H pin 1103 is further connected to a trailer preceding CAN bus level signal processing circuit 1113, which performs necessary processing on the voltage signal of the preceding CAN _ H pin, such as isolation, voltage division, filtering, etc., the specific processing method of the present invention is not limited, and the processed level signal enters the trailer preceding CAN bus level signal acquisition port 1114 for acquisition and subsequent processing by the trailer network management unit 1110. In addition, the trailer is also provided with an ISO 7638 subsequent socket 1105 and connected to an ISO 7638 connector 5 between the trailer, the subsequent socket 1105 CAN be a stand-alone dedicated socket, and CAN be integrated into a larger socket as a part of a pin or distributed into a plurality of sockets, without affecting the core idea of the invention, and the subsequent socket comprises a subsequent CAN _ H pin 1107 and a subsequent CAN _ L pin 1108 which are connected to a subsequent 24V CAN transceiver 1123 and a subsequent 5V CAN transceiver 1125 at the same time. The trailer network management unit 1110 has a subsequent 24V CAN transceiver enable pin 1124 and a subsequent 5V CAN transceiver enable pin 1126 for enabling/disabling the subsequent 24V CAN transceiver 1123 and the subsequent 5V CAN transceiver 1125, respectively. The trailer network management unit 1110 has a subsequent CAN channel 1112, whose subsequent CAN receive pin 1128 and subsequent CAN transmit pin 1127 are connected to both a subsequent 24V CAN transceiver 1123 and a subsequent 5V CAN transceiver 1125, which CAN be connected to and CAN communicate with a subsequent CAN bus (subsequent CAN _ H pin 1107 and subsequent CAN _ L pin 1108) via one of the two CAN transceivers. The subsequent CAN _ H pin 1107 is further connected to a trailer subsequent CAN bus level signal processing circuit 1121, which performs necessary processing on the voltage signal of the subsequent CAN _ H pin, such as isolation, voltage division, filtering, and the like, and the specific processing manner of the present invention is not limited thereto, and the processed level signal enters the trailer subsequent CAN bus level signal acquisition port 1122, and is acquired and subsequently processed by the trailer network management unit 1110. The trailer network management unit 1110 and the brake control unit 1129 also have a data channel 1109 for exchanging data. Furthermore, the trailer network management unit 1110 and the brake control unit 1129 may also be integrated in one processing unit.

The process of establishing CAN communication between the tractor 1 and the first, second and third trailers 2, 3, 4 in this embodiment is shown in fig. 5:

1) the system is powered up, and the tractor electronic brake unit (EBS) 10 and the electronic brake units (EBS) 11 of all trailers complete a power-up self-test and other necessary initialization operations.

2) The tractor electronic brake unit (EBS) 10 and all trailer electronic brake units (EBS) 11 enable all 5V CAN transceivers that are themselves connected to the ISO 7638 connector 5, disable all 24V CAN transceivers, and enter the CAN bus listening mode (receive messages only, not send any messages and respond to the padding bits). This process is not necessarily performed synchronously, for example, the power-on time is divided into successive times or an intermediate temporary access is performed.

3) The tractor electronic brake unit (EBS) 10 detects the voltage of the tractor CAN _ H pin through the tractor CAN bus level signal collection port 1013, and the electronic brake units (EBS) 11 of the first, second, and third trailers 2, 3, and 4 detect the voltages of their own preceding and subsequent CAN _ H pins through their preceding and subsequent CAN bus level signal collection ports 1113 and 1122, respectively.

4) The tractor electronic brake unit (EBS) 10 and the electronic brake units (EBS) 11 of all trailers judge whether the voltage of the CAN _ H pin is in the range of 5V CAN communication standard (ISO 11898), if so, the corresponding CAN channel adopts 5V CAN communication and enters a subsequent normal communication mode; and if not, entering the next step, and judging whether the communication is in the 24V CAN communication standard range.

5) The tractor electronic brake unit (EBS) 10 and all trailer electronic brake units (EBS) 11 judge whether the voltage of the CAN _ H pin is in the range of 24V CAN communication standard (ISO 11992), if so, the corresponding CAN channel adopts 24V CAN communication and enters the next step to switch the corresponding channel to 24V CAN communication; otherwise, returning to the step 3) to continuously detect the voltage of the CAN _ H pin.

6) The tractor electronic brake unit (EBS) 10 and the electronic brake units (EBS) 11 of all trailers each disable the 5V CAN transceiver of the corresponding CAN channel and enable the 24V CAN transceiver of the corresponding CAN channel, thereby switching the corresponding CAN channel to 24V CAN communication.

7) After the CAN channel is switched to a correct bus communication level, the channel enters a normal communication mode: according to the specification requirements of ISO 11992, network initialization and message forwarding are performed, and application messages are normally received/sent.

8) In the normal communication mode, if the CAN bus of a certain CAN channel is detected to be closed or the communication connection is disconnected (such as bus fault or node disconnection), the step 3) is returned to detect the CAN _ H pin voltage of the corresponding CAN channel again.

By the above process and method, the tractor 1 and the first, second and third trailers 2, 3, 4 CAN establish correct CAN communication connections. In this example both the tractor 1 and all trailers support both 24V and 5V CAN communication levels, so the end result is necessarily that all CAN channels use 5V CAN communication levels. The network management unit and the brake control unit in the electronic brake unit are integrated into one processing unit, and a plurality of independent CAN transceivers with different communication voltages are not adopted, but a combination of the transceiver and an auxiliary circuit with the same multi-voltage communication function is adopted, and the like, and the extension and the modification of the application are regarded as the core idea of the invention and are protected.

Example 2

This embodiment is different from embodiment 1 in that: the first trailer 2 only supports 24V CAN communication, the third trailer 4 only supports 5V CAN communication, the tractor 1 and the second trailer 3 simultaneously support 24V CAN and 5V CAN communication, and after the CAN communication connection is established according to the process and the method, finally 24V CAN communication is performed between the tractor 1 and the first trailer 2, 24V CAN communication is performed between the first trailer 2 and the second trailer 3, and 5V CAN communication is performed between the second trailer 3 and the third trailer 4.

Example 3

This embodiment is different from embodiment 1 in that: the CAN _ H pin level is detected instead of being detected by detecting the CAN _ L pin level in the communication establishing process.

Example 4

This embodiment is different from embodiment 1 in that: the CAN _ L pin level and the CAN _ H pin level are detected in the communication establishing process to replace the detection of the CAN _ H pin level.

Example 5

This embodiment is different from embodiment 1 in that: the CAN transceiver units in the trailer electronic brake unit and the tractor electronic brake unit comprise one or two of a 24V CAN transceiver, a 12V CAN transceiver and a 5V CAN transceiver or simultaneously comprise the 24V CAN transceiver, the 12V CAN transceiver and the 5V CAN transceiver, so that any one, any two or three of 24V, 12V and 5V CAN communication are supported, and after the power-on initialization is completed, the CAN transceiver with the lowest communication level is enabled by default and the other transceivers are forbidden.

Example 6

This embodiment is different from embodiment 1 in that: the tractor electric brake unit comprises 2 or more second sockets and the trailer electric brake unit is provided with two or more preceding ISO 7638 sockets or subsequent ISO 7638 sockets.

In summary, the above-mentioned embodiments are only preferred embodiments of the present invention, and all equivalent changes and modifications made in the claims of the present invention should be covered by the claims of the present invention.

Claims (10)

1. A vehicle electrical and CAN communication connection establishing device is characterized in that: the tractor electronic brake unit and the trailer electronic brake unit are electrically connected through an ISO 7638 joint; the tractor electronic brake unit is provided with a first socket and a second socket, the tractor electronic brake unit comprises a tractor network management unit and a tractor brake control unit, the first socket is used for supplying power to the tractor network management unit and the tractor brake control unit through pin combination and is connected to the second socket, the second socket is connected to a plug, a CAN _ H pin and a CAN _ L pin are arranged in the second socket, a tractor CAN transceiver unit is arranged in the tractor electronic brake unit, the CAN _ H pin and the CAN _ L pin are both connected to the tractor CAN transceiver unit, the tractor CAN transceiver unit is enabled or disabled through an enabling pin on the tractor network management unit, the tractor CAN transceiver unit is in communication connection with the tractor network management unit, and the tractor network management unit is connected with the CAN _ H pin or/and the CAN _ L pin through the CAN transceiver unit to perform CAN communication; level signals of the CAN _ H pin or/and level signals of the CAN _ L pin enter a CAN bus level signal acquisition port of the tractor, and are acquired and subsequently processed by a tractor network management unit; the trailer electronic brake unit comprises a previous socket which CAN be connected to an ISO 7638 connector between the trailer electronic brake unit and a previous vehicle, the trailer electronic brake unit further comprises a trailer network management unit and a trailer brake control unit, a previous CAN _ H pin and a previous CAN _ L pin are arranged in the previous socket, the previous CAN _ H pin and the previous CAN _ L pin are both connected to the previous CAN transceiver unit, and the trailer network management unit enables or disables the previous CAN transceiver unit through an enabling pin; the trailer network management unit is provided with a previous CAN channel, is connected to a previous CAN transceiver unit through the previous CAN channel, is connected with a previous CAN _ H pin or/and a previous CAN _ L pin through the previous CAN transceiver unit and carries out CAN communication; the previous CAN _ H pin or/and the previous CAN _ L pin level signal enter a trailer previous CAN bus level signal acquisition port, and the trailer network management unit performs acquisition and subsequent processing; at least one CAN transceiver with the same level exists in the tractor CAN transceiver unit and the previous CAN transceiver unit.

2. A vehicle electrical and CAN communication connection establishing apparatus according to claim 1, wherein: the subsequent socket is connected to the subsequent socket, the subsequent socket CAN be connected to a joint between subsequent trailers, a subsequent CAN _ H pin and a subsequent CAN _ L pin are arranged in the subsequent socket, the subsequent CAN _ H pin and the subsequent CAN _ L pin are both connected to a subsequent CAN transceiver unit, and the trailer network management unit enables or disables the subsequent CAN transceiver unit through enabling pins respectively; the trailer network management unit has a subsequent CAN channel and is connected to the subsequent CAN transceiver units via the subsequent CAN channel and is connected to and CAN-communicates with the subsequent CAN _ H pin or/and the subsequent CAN _ L pin via one of the subsequent CAN transceiver units.

3. A vehicle electrical and CAN communication connection establishing apparatus according to claim 2, wherein: the tractor electronic brake unit also comprises a CAN bus level signal processing circuit, the CAN bus level signal processing circuit is connected with a CAN _ H pin or/and a CAN _ L pin and processes a voltage signal of the CAN _ H pin or a voltage signal of the CAN _ L pin, and the processed level signal enters a tractor CAN bus level signal acquisition port; the tractor network management unit and the brake control unit carry out data interaction through data communication; the previous CAN _ H pin or/and the previous CAN _ L pin are/is also connected to a trailer previous CAN bus level signal processing circuit, the processing circuit processes voltage signals of the previous CAN _ H pin or/and the previous CAN _ L pin, the processed level signals enter a trailer previous CAN bus level signal acquisition port, and the trailer network management unit performs acquisition and subsequent processing; the trailer network management unit and the trailer brake control unit carry out data interaction through data communication, a subsequent CAN _ H pin or/and a subsequent CAN _ L pin are/is also connected to a subsequent CAN bus level signal processing circuit of the trailer, the processing circuit processes a voltage signal of the subsequent CAN _ H pin, the processed level signal enters a subsequent CAN bus level signal acquisition port of the trailer, and the trailer network management unit carries out acquisition and subsequent processing; the trailer network management unit and the brake control unit also have a data channel for exchanging data.

4. A vehicle electrical and CAN communication connection establishing apparatus according to claim 3, wherein: the number of the trailer electronic brake units is at least two, the adjacent trailer electronic brake units are electrically connected through ISO 7638 joints, the adjacent trailer electronic brake units are in CAN communication with the previous CAN transceiver unit of the rear trailer electronic brake unit through the subsequent CAN transceiver unit of the previous trailer electronic brake unit, and at least one CAN transceiver with the same level exists between the subsequent CAN transceiver unit of the previous trailer electronic brake unit and the previous CAN transceiver unit of the rear trailer electronic brake unit.

5. A vehicle electrical and CAN communication connection establishing apparatus according to claim 1, wherein: the tractor CAN transceiver unit comprises one or two of a 24V CAN transceiver, a 12V CAN transceiver and a 5V CAN transceiver or simultaneously comprises the 24V CAN transceiver, the 12V CAN transceiver and the 5V CAN transceiver; the preceding CAN transceiver unit comprises one or two of a 24V CAN transceiver, a 12V CAN transceiver and a 5V CAN transceiver or simultaneously comprises a 24V CAN transceiver, a 12V CAN transceiver and a 5V CAN transceiver; when the types of the CAN transceivers in the tractor CAN transceiver units are two or three, the tractor network management unit CAN enable/disable each CAN transceiver independently, and the tractor network management unit is connected with a CAN _ H pin or/and a CAN _ L pin through one of the two or three CAN transceivers to carry out CAN communication; when the types of the CAN transceivers in the previous CAN transceiver units are two or three, the trailer network management unit CAN enable/disable each CAN transceiver independently, and the trailer network management unit is connected with the CAN _ H pin or/and the CAN _ L pin through one of the two or three CAN transceivers to carry out CAN communication.

6. A vehicle electrical and CAN communication connection establishing apparatus according to claim 3, wherein: the subsequent CAN transceiver unit comprises one or two of a 24V CAN transceiver, a 12V CAN transceiver and a 5V CAN transceiver or simultaneously comprises the 24V CAN transceiver, the 12V CAN transceiver and the 5V CAN transceiver; when the types of the CAN transceivers in the subsequent CAN transceiver units are two or three, the trailer network management unit CAN enable/disable each CAN transceiver independently, and the trailer network management unit is connected with the CAN _ H pin or/and the CAN _ L pin through one of the two or three CAN transceivers to carry out CAN communication.

7. A vehicle electrical and CAN communication connection establishing apparatus according to claim 1, wherein: the trailer network management unit and the trailer brake control unit are integrated in one processing unit, or/and the tractor network management unit and the tractor brake control unit are integrated in one processing unit.

8. A vehicle electrical and CAN communication connection establishing apparatus according to claim 1, wherein: the first socket comprises a pin combination, the second socket comprises a pin combination, the pin combination of the first socket supplies power for the tractor network management unit and the trailer brake control unit, and the pin combination of the first socket is connected with the pin combination of the second socket; the pin combination of the previous socket supplies power for the trailer network management unit and the trailer brake control unit and is connected to the pin combination of the subsequent socket, and the pin combination of the previous socket is connected with the pin combination of the subsequent socket.

9. A vehicle electrical and CAN communication connection establishing method is characterized in that: including the vehicle electrical and CAN communication connection establishing apparatus of claim 4, the CAN establishing connection process between the tractor and the trailer and between the trailer and the trailer comprising the steps of:

the method comprises the following steps that firstly, a system is electrified, and the tractor electronic brake unit and the trailer electronic brake unit complete electrification self-check;

step two, enabling 5V CAN transceivers in all CAN transceiver units connected with the ISO 7638 joint by the tractor electronic brake unit and all trailer electronic brake units, forbidding CAN transceivers of other levels, and entering a CAN bus monitoring mode;

step three, the tractor electronic brake unit detects the signal level received by the tractor CAN bus, and the trailer electronic brake unit detects the voltage of the previous CAN signal of the trailer electronic brake unit through the previous CAN bus level signal acquisition port and detects the voltage of the subsequent CAN signal of the trailer electronic brake unit through the subsequent CAN bus level signal acquisition port;

step four, the tractor electronic brake unit and all trailer electronic brake units judge whether the CAN signal voltage received by the CAN bus interface is within the communication standard range of 5V CAN, if so, the corresponding CAN channel adopts 5V CAN communication and enters a subsequent normal communication mode; otherwise, entering the next step, and judging whether the communication is in the 24V CAN communication standard range;

step five, the tractor electronic brake unit and all trailer electronic brake units judge whether the CAN signal voltage received by the CAN bus interface is in a 24V communication standard range, if so, the corresponding CAN channel adopts 24V CAN communication and enters the next step to switch the corresponding channel to 24V CAN communication; otherwise, entering a step three to continuously detect the CAN signal voltage;

step six, the tractor electronic brake unit and the trailer electronic brake unit respectively forbid the 5V CAN transceivers of the corresponding CAN channels, and enable the 24V CAN transceivers of the corresponding CAN channels, so that the corresponding CAN channels are switched to 24V CAN communication;

and step seven, after the CAN channel is switched to the correct bus communication level, the channel enters a normal communication mode: according to the specification requirements of ISO 11992, network initialization and message forwarding are performed, and application messages are normally received/sent.

10. A vehicle electrical and CAN communication connection establishment method according to claim 9, characterized by: step five, when the tractor electronic brake unit and all trailer electronic brake units judge that the CAN signal voltage received by the CAN bus interface is not in the 5V CAN communication standard range and not in the 24V communication standard range, judging whether the CAN signal voltage is in the 12V CAN communication range, if so, adopting 12V CAN communication for the corresponding CAN channel and entering the next step to switch the corresponding channel to 12V CAN communication, and respectively forbidding the 5V CAN transceivers of the corresponding CAN channels of the tractor electronic brake unit and the trailer electronic brake unit to enable the 12V CAN transceivers of the corresponding CAN channels, so that the corresponding CAN channels are switched to 12V CAN communication; if not, the step three is entered to continue to detect the CAN signal voltage.

Images