A system and method based on configurable terminal resistance of intelligent power distribution module

Abstract

A system based on configurable terminal resistance of intelligent power distribution module comprises: EOL equipment, OBD interface, configuration terminal and vehicle-wide CAN communication nodes, characterized in that the EOL equipment is connected with the OBD equipment, the vehicle-wide CAN communication nodes are connected to form various CAN network segments through a CAN bus, the OBD interface is provided with a plurality of branch nodes, each branch node of the OBD interface is connected to the configuration terminal through a CAN network segment, a terminal node is provided in the configuration terminal, and the branch node and the terminal node serve as fixed nodes of each network segment; the early hardware design of all node modules of the present invention does not need to consider whether to reserve terminal resistance, all adopt standardized circuit design, and the terminal resistance is uniformly configured during the offline process, thereby improving the platformization and universalization rate of components and reducing the complexity and error probability of early design.

Description

Technical Field

[0001] The present invention relates to the technical field of Internet vehicles, and in particular to a system and method based on configurable terminal resistance of an intelligent power distribution module. Background Art

[0002] With the development of intelligent connected vehicles, the number of controller modules in vehicles has gradually increased, and the requirements for information exchange rate and stability between modules have become increasingly higher. Information exchange between modules is mainly carried out through the CAN (Controller Area Network, hereinafter referred to as CAN) bus, and the communication baud rate is generally above 2Mbps. Such a high transmission rate has strict requirements on the length of the bus trunk and the length of the node branch: generally, the trunk length is required to be no more than 30m, and the branch length is required to be no more than 1m. However, there are more and more modules on the CAN bus for communication on autonomous driving vehicles, resulting in an increasing number of bus node modules and an increasingly complex bus network, which is difficult to meet such strict requirements. The physical layer protocol of the CAN bus stipulates that the CAN bus network adopts a bus topology structure. Nodes on the network exchange information through this bus, and there is no master-slave relationship between the nodes. In order to match the characteristic impedance of the transmission line and improve the anti-interference ability of the CAN bus, it is necessary to connect a 120-ohm terminal resistor to each of the two farthest nodes on the bus. The main functions of the bus terminal resistor are: (1) to improve the anti-interference ability; (2) to ensure that the bus quickly enters the recessive state; (3) to match the bus impedance and improve the signal quality. It is placed at both ends of the bus to reduce the reflected energy. The same module is placed in different positions and quantities in different models or even in different configurations of the same model, resulting in different configurations for different models. The lengths of the trunk and branches of the same CAN network segment vary greatly, even exceeding the total length requirement, causing bus communication failures and affecting the driving safety of self-driving cars. Therefore, it is particularly important to flexibly configure the module terminal resistance for different models and configurations in self-driving cars.

[0003] China Patents published an invention patent titled A system, method and circuit for configuring CAN terminal resistance of an autonomous driving vehicle module. The patent publication number is CN117579478A. The terminal resistance configuration method disclosed in the patent requires adding a LIN bus network to the original vehicle's CAN network, which is not only complex to implement but also costly. Therefore, in order to solve this problem, this design proposes a system and method based on the configurable terminal resistance of the intelligent distribution module to solve the problems of unreasonable terminal resistance settings, inflexible configuration, and inconsistency with the actual physical terminals of the vehicle models in the past. Summary of the invention

[0004] The present invention aims to provide a system and method based on configurable terminal resistance of an intelligent power distribution module.

[0005] A system based on configurable terminal resistance of an intelligent power distribution module comprises: an EOL device, an OBD interface, a configuration terminal and a vehicle-wide CAN communication node, wherein the EOL device is connected to the OBD device, the vehicle-wide CAN communication nodes are connected to form various CAN network segments via a CAN bus, the OBD interface is provided with a plurality of branch nodes, each branch node of the OBD interface is connected to the configuration terminal via a CAN network segment, a terminal node is provided in the configuration terminal, and the branch nodes and the terminal nodes serve as fixed nodes of each network segment.

[0006] Preferably, the whole vehicle CAN communication node circuit includes a processor MCU, a CAN controller, a CAN transceiver, a terminal resistor R1, and a switch tube Q1. The terminal resistor R1 is connected in parallel between the bus CAN-H and CAN-L through the switch tube Q1. The control end of the switch tube Q1 is respectively connected to the P1 pin of each node MCU. The bus CAN-H and CAN-L are connected to the CAN transceiver, and the other end of the CAN transceiver is connected to the CAN controller.

[0007] Preferably, a plurality of the vehicle-wide CAN communication nodes form a network segment, and a plurality of the network segments form a smart power distribution vehicle CAN communication network, and the two farthest nodes on the smart power distribution vehicle CAN communication network act as terminal nodes.

[0008] Preferably, the CAN transceiver is used for receiving and sending data on a CAN bus, and the CAN controller is used for managing and controlling area network communications.

[0009] A method for configurable terminal resistance of an intelligent power distribution module, characterized in that it comprises the following steps: Step 1: a preset terminal resistance information library, wherein the terminal resistance information library includes a vehicle type identification code and a terminal node name corresponding to each network segment; Step 2: The EOL device is connected to the OBD via the CAN bus, and the configuration terminal is connected as a fixed terminal of all network segments to the OBD and the ECU nodes of each network segment via the CAN bus; Step 3: When the vehicle is offline, it is powered on for the first time for initialization, and the configuration terminal cuts off the power supply of all nodes by default; Step 4: Obtain or scan the vehicle model identification code of the vehicle, and input the vehicle model identification code into the terminal resistance information library; Step 5: Obtain the terminal node name of each network segment corresponding to the vehicle type identification code, and the EOL device sends the terminal resistance configuration instruction of each network segment to the configuration terminal through the OBD interface; Step 6: Since each node has a terminal resistor by default after power-on, there will be multiple terminal resistors in the same network segment, which will cause the bus to be unable to communicate. Therefore, all nodes cannot be powered on at the same time during configuration. The terminal resistor of the module can only be configured by powering on one module separately each time.

[0010] The beneficial effects of the above scheme are: 1. The preliminary hardware design of all node modules of the present invention does not need to consider whether to reserve terminal resistance. All adopt standardized circuit design, and the terminal resistance is uniformly configured during the offline process, which improves the platformization and universalization rate of components and reduces the complexity and error probability of preliminary design.

[0011] 2. The present invention does not need to add or change the original vehicle network connection. It only needs to upgrade the original vehicle gateway to a configuration terminal with power distribution function. The configuration terminal independently controls the power supply of each node module to configure the node, solving the problem of being unable to communicate before the network is configured.

[0012] 3. The present invention resets and powers off the node modules that have failed to be configured by configuring the terminal integrated intelligent power distribution switch, thereby avoiding configuration failure caused by recoverable node failures and communication abnormalities of other nodes in the vehicle caused by unrecoverable failures. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is the CAN network topology diagram of the present invention; Figure 2 This is a structural diagram of a module terminal resistance configurable system based on intelligent power distribution of the present invention; Figure 3 A circuit diagram of a module with configurable terminal resistance based on intelligent power distribution according to the present invention; Figure 4 The present invention is a flow chart of a method for configurable module terminal resistance based on intelligent power distribution. DETAILED DESCRIPTION

[0014] The present invention is further explained clearly and completely below in conjunction with the accompanying drawings of the specification, but the protection scope of the present invention is not limited thereto.

[0015] A system based on configurable terminal resistance of intelligent power distribution module, comprising: EOL equipment, OBD interface, configuration terminal and vehicle CAN communication nodes, wherein, Figure 2As shown, the EOL device is connected to the OBD device, the CAN communication nodes of the whole vehicle are connected through the CAN bus to form each CAN network segment, the OBD interface is provided with multiple branch nodes, each branch node of the OBD interface is connected to the configuration terminal through a CAN network segment, and the configuration terminal is provided with a terminal node, and the branch node and the terminal node serve as fixed nodes of each network segment. In addition, the configuration terminal integrates gateway and power distribution functions, and the power supply of all module nodes of the whole vehicle is independently controlled by the configuration terminal through an independent power distribution switch efuse.

[0016] Specifically, Figure 3 As shown, the vehicle-wide CAN communication node circuit includes a processor MCU, a CAN controller, a CAN transceiver, a terminal resistor R1, and a switch tube Q1. The terminal resistor R1 is connected in parallel between the bus CAN-H and CAN-L through the switch tube Q1. The control end of the switch tube Q1 is respectively connected to the P1 pin of each node MCU. The bus CAN-H and CAN-L are connected to the CAN transceiver, and the other end of the CAN transceiver is connected to the CAN controller.

[0017] Specifically, Figure 1 As shown, multiple CAN communication nodes in the vehicle form a network segment, and multiple network segments form a CAN communication network for intelligent power distribution vehicles. The two farthest nodes on the CAN communication network of the intelligent power distribution vehicle act as terminal nodes, and terminal resistors need to be connected to the CAN interface circuit respectively. In actual applications, the hardware circuits are designed in advance, so they cannot be changed later, resulting in the inability of the hardware to match different vehicle models for flexibly configuration.

[0018] Specifically, the CAN transceiver is used for receiving and sending data on the CAN bus, and the CAN controller is used for managing and controlling area network communications.

[0019] like Figure 4 As shown, a method based on configurable terminal resistance of an intelligent power distribution module is characterized in that it includes the following steps: Step 1: a preset terminal resistance information library, wherein the terminal resistance information library includes a vehicle type identification code and a terminal node name corresponding to each network segment; Step 2: The EOL device is connected to the OBD via the CAN bus, and the configuration terminal is connected as a fixed terminal of all network segments to the OBD and the ECU nodes of each network segment via the CAN bus; Step 3: When the vehicle is offline, it is powered on for the first time for initialization, and the configuration terminal cuts off the power supply of all nodes by default; Step 4: Obtain or scan the vehicle model identification code of the vehicle, and input the vehicle model identification code into the terminal resistance information library; Step 5: Obtain the terminal node name of each network segment corresponding to the vehicle type identification code, and the EOL device sends the terminal resistance configuration instruction of each network segment to the configuration terminal through the OBD interface; Step 6: Since each node has a terminal resistor by default after power-on, there will be multiple terminal resistors in the same network segment, which will cause the bus to be unable to communicate. Therefore, all nodes cannot be powered on at the same time during configuration. The terminal resistor of the module can only be configured by powering on one module separately each time. Check whether the configuration is successful. When configuring the first node of the network segment (taking A2 in network segment A as an example), first control the power distribution switch of the node (EFUSEA2 for A2 node) to turn on. At this time, the node MCU controls the MOS tube Q1 to turn on by default, and the node is configured with terminal resistance. Since only the node, the configuration terminal and the OBD are online on the network segment, and only the configuration terminal and the node have terminal resistance, the network can communicate normally. After the configuration terminal sends a configuration instruction to the node, when the configuration instruction is to turn on the terminal resistance, the node will maintain the current state of Q1 and feedback the configuration success signal to the configuration terminal. When the configuration instruction is to turn off the terminal resistance, the node MCU will control the Q1 MOS to cut off and feedback the configuration success signal to the configuration terminal. At this time, the node does not have a terminal resistance.

[0020] When configuring the next node in the network segment, first control the power distribution switch Nn-1 of the previous node to close, and then control the power distribution switch EFUSENn of the current node Nn to open. At this time, the MCU of the Nn node controls the MOS tube Q1 to turn on by default, and configures the terminal resistor by default. At this time, there are still only the Nn-1 node, the configuration terminal and the OBD online on the network segment, and the configuration terminal and the Nn-1 node have terminal resistors, so the network can communicate normally. After the configuration terminal sends a configuration instruction to the Nn-1 node, when the configuration instruction is to turn on the terminal resistor, the Nn-1 node will maintain the current state of Q1 and feedback the configuration success signal to the configuration terminal; when the configuration instruction is to turn off the terminal resistor, the Nn-1 node MCU will control the Q1 MOS to cut off and feedback the configuration success signal to the configuration terminal. At this time, the Nn-1 node does not have a terminal resistor.

[0021] If the node feedbacks a configuration failure signal, the configuration terminal will control the power switch of the node to turn on and off three times in succession to reset the power of the node, and then re-execute the configuration. If the configuration still fails, the power supply of the node will be cut off and the node configuration failure instruction will be fed back to the diagnostic device.

[0022] When the terminal resistances of all network segments are configured successfully in sequence, the configuration terminal turns on the power distribution switches of all network segment nodes again at the same time and feeds back a configuration success signal to the diagnostic device.

[0023] In the present invention, the early hardware design of all node modules does not need to consider whether to reserve terminal resistance. All of them adopt standardized circuit design, and the terminal resistance is uniformly configured during the offline process, which improves the platformization and universality of parts and components, and reduces the complexity and error probability of early design; there is no need to add or change the original vehicle network connection, only the original vehicle gateway needs to be upgraded to a configuration terminal with power distribution function, and the node is configured by independently controlling the power supply of each node module through the configuration terminal, which solves the problem of being unable to communicate before the network is configured; the node module that fails to be configured is reset and powered off by the intelligent power distribution switch integrated in the configuration terminal, so as to avoid configuration failure caused by recoverable node failures and abnormal communication of other nodes in the whole vehicle caused by unrecoverable failures.

Claims

1. A system based on configurable terminal resistance of intelligent power distribution module, comprising: EOL equipment, OBD interface, configuration terminal and vehicle-wide CAN communication nodes, characterized in that the EOL equipment is connected to the OBD equipment, the vehicle-wide CAN communication nodes are connected through a CAN bus to form various CAN network segments, the OBD interface is provided with multiple branch nodes, each branch node of the OBD interface is connected to the configuration terminal through a CAN network segment, the configuration terminal is provided with a terminal node, and the branch node and the terminal node serve as fixed nodes for each network segment.

2. A system based on configurable terminal resistance of intelligent power distribution module as claimed in claim 1, characterized in that: The vehicle-wide CAN communication node circuit includes a processor MCU, a CAN controller, a CAN transceiver, a terminal resistor R1, and a switch tube Q1. The terminal resistor R1 is connected in parallel between the bus CAN-H and CAN-L through the switch tube Q1. The control end of the switch tube Q1 is respectively connected to the P1 pin of each node MCU. The bus CAN-H and CAN-L are connected to the CAN transceiver, and the other end of the CAN transceiver is connected to the CAN controller.

3. A system based on configurable terminal resistance of intelligent power distribution module as claimed in claim 1, characterized in that: A plurality of the vehicle-wide CAN communication nodes form a network segment, and a plurality of the network segments form a smart power distribution vehicle CAN communication network. The two farthest nodes on the smart power distribution vehicle CAN communication network act as terminal nodes.

4. A system based on configurable terminal resistance of intelligent power distribution module as claimed in claim 1, characterized in that: The CAN transceiver is used for receiving and sending data on the CAN bus, and the CAN controller is used for managing and controlling area network communications.

5. A method based on configurable terminal resistance of intelligent power distribution module, characterized in that: The following steps are involved: Step 1: a preset terminal resistance information library, wherein the terminal resistance information library includes a vehicle type identification code and a terminal node name corresponding to each network segment; Step 2: The EOL device is connected to the OBD via the CAN bus, and the configuration terminal is connected as a fixed terminal of all network segments to the OBD and the ECU nodes of each network segment via the CAN bus; Step 3: When the vehicle is offline, it is powered on for the first time for initialization, and the configuration terminal cuts off the power supply of all nodes by default; Step 4: Obtain or scan the vehicle model identification code of the vehicle, and input the vehicle model identification code into the terminal resistance information library; Step 5: Obtain the terminal node name of each network segment corresponding to the vehicle type identification code, and the EOL device sends the terminal resistance configuration instruction of each network segment to the configuration terminal through the OBD interface; Step 6: Since each node has a terminal resistor by default after power-on, there will be multiple terminal resistors in the same network segment, which will cause the bus to be unable to communicate. Therefore, all nodes cannot be powered on at the same time during configuration. The terminal resistor of the module can only be configured by powering on one module separately each time.

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