CAN node terminal resistance management method, device and CAN node terminal resistance detection circuit

Abstract

The present application relates to a CAN node terminal resistance management method, device and CAN node terminal resistance detection circuit. The method comprises: when the ACU is powered on, obtaining the resistance value of the external input and output of the CAN transceiver of the CAN node through the CAN node terminal resistance detection circuit; if the resistance value of the external input and output of the CAN transceiver of the CAN node is a preset resistance value R set , then the MCU of other CAN nodes in the ACU is notified to configure the resistance value of the CAN transceiver of other CAN nodes to the preset resistance value R set resistance; if the resistance value of the CAN node CAN transceiver to the external input and output is R set / 2, then the MCU of other CAN nodes is notified that there is no need to configure resistors at the external input and output of the CAN transceiver of other CAN nodes; if the CAN node terminal resistance detection circuit is mounted with a resistor value of the preset resistance R set The resistance of the CAN node CAN transceiver is R set / N, the resistance value of the resistor mounted on the CAN node terminal resistance detection circuit is made infinite through the CAN node terminal resistance detection circuit.

Description

Technical Field

[0001] The present application relates to the field of autonomous driving, and in particular to a CAN node terminal resistance management method and device and a CAN node terminal resistance detection circuit. Background Art

[0002] As an intelligent computing platform, the automated driving control unit (ACU) is aimed at L3 / L4 unmanned driving applications. It can integrate computationally intensive sensor data processing and sensor fusion work with control strategy development into a control unit and help establish a structured and organized vehicle controller network. Generally speaking, the ACU includes a network composed of a microcontroller (MCU) and a controller area network (CAN) transceiver, where an MCU and a CAN transceiver can be classified as a CAN node of the network, and the CAN transceivers of the CAN nodes are connected to each other through the CAN bus. According to the physical layer provisions of the CAN protocol, there must be two CAN transceivers on the CAN bus (for example, the farthest or end CAN transceiver of the CAN bus) and the external entrances and exits must be connected in series with a fixed resistance (for example, 120Ω) resistor (called "CAN node terminal resistor"), and other CAN transceivers do not need to be connected in series with the external entrances and exits. For ACU, in actual application, it is easy to miss soldering or solder an extra resistor at the external entrance and exit of the CAN transceiver. For example, in addition to connecting a terminal resistor in series at each of the two external entrances and exits of the ACU CAN transceiver, terminal resistors are also connected in series at other external entrances and exits of the CAN transceiver. Alternatively, only one external entrance and exit of the ACU CAN transceiver is connected in series with a terminal resistor, and no terminal resistor is connected in series at other external entrances and exits of the CAN transceiver. In order to detect the above errors, the relevant technology relies on files or documents, and the CAN nodes with incorrect series resistors are checked one by one manually according to the instructions of the files or documents. However, this method has significant shortcomings both in terms of efficiency and accuracy. For example, there are errors caused by carelessness during manual inspection, or it is easy to miss inspections when the network is complex and there are many CAN nodes, etc. Summary of the invention

[0003] In order to solve or partially solve the problems existing in the related technology, the present application provides a CAN node terminal resistance management method, device and CAN node terminal resistance detection circuit, which can automatically detect whether the terminal resistance of the ACU's CAN node external entrance and exit is incorrectly welded, thereby improving detection efficiency and accuracy.

[0004] In a first aspect, the present application provides a CAN node terminal resistance management method, which is applied to an autonomous driving domain controller ACU comprising at least two CAN nodes, wherein each of the at least two CAN nodes comprises a microcontroller MCU and a CAN transceiver, and the method comprises:

[0005] When the ACU is powered on, the resistance value of the external input and output of the CAN transceiver of the current CAN node is obtained through the CAN node terminal resistance detection circuit, and the current CAN node is any one of the at least two CAN nodes;

[0006] If the resistance value of the external input and output of the CAN transceiver of the CAN node is the preset resistance value R set , then notify the MCU of other CAN nodes in the ACU to configure the resistance value of the CAN transceiver of the other CAN nodes to be the preset resistance value R set The external input of the CAN transceiver of the CAN node is connected to the external input of the CAN transceiver of the other CAN nodes, and the external output of the CAN transceiver of the CAN node is connected to the external output of the CAN transceiver of the other CAN nodes;

[0007] If the resistance value of the CAN node CAN transceiver to the external input and output is R set / 2, then notify the MCU of the other CAN nodes that there is no need to configure resistors at the external inlet and outlet of the CAN transceiver of the other CAN nodes;

[0008] If the CAN node terminal resistance detection circuit is mounted with a resistance value of the preset resistance value R set The resistance of the CAN node CAN transceiver is R set / N, then the resistance value of the resistor mounted on the CAN node terminal resistance detection circuit is made infinite through the CAN node terminal resistance detection circuit, and N is an integer not less than 3.

[0009] A second aspect of the present application provides a CAN node terminal resistance management device, which is applied to an autonomous driving domain controller ACU comprising at least two CAN nodes, wherein each of the at least two CAN nodes comprises a microcontroller MCU and a CAN transceiver, including:

[0010] an acquisition module, configured to acquire the resistance value of the external inlet and outlet of the CAN transceiver of the current CAN node through the CAN node terminal resistance detection circuit when the ACU is powered on, wherein the current CAN node is any one of the at least two CAN nodes;

[0011] The first notification module is used to notify the user if the resistance value of the external input and output of the CAN transceiver of the CAN node is a preset resistance value R set , then notify the MCU of other CAN nodes in the ACU to configure the resistance value of the CAN transceiver of the other CAN nodes to be the preset resistance value R set The external input of the CAN transceiver of the CAN node is connected to the external input of the CAN transceiver of the other CAN nodes, and the external output of the CAN transceiver of the CAN node is connected to the external output of the CAN transceiver of the other CAN nodes;

[0012] The second notification module is used to notify the user if the resistance value of the external input and output of the CAN transceiver of the CAN node is R set / 2, then notify the MCU of the other CAN nodes that there is no need to configure resistors at the external inlet and outlet of the CAN transceiver of the other CAN nodes;

[0013] The enabling module is used to enable the CAN node terminal resistance detection circuit to mount a resistor with a preset resistance value R set The resistance of the CAN node CAN transceiver is R set / N, then the resistance value of the resistor mounted on the CAN node terminal resistance detection circuit is made infinite through the CAN node terminal resistance detection circuit, and N is an integer not less than 3.

[0014] In a third aspect, the present application provides a CAN node terminal resistance detection circuit, which is applied to an autonomous driving domain controller ACU comprising at least two CAN nodes, wherein each of the at least two CAN nodes comprises a microcontroller MCU and a CAN transceiver, and the CAN node terminal resistance detection circuit comprises a current source, a first switch tube, a second switch tube, a third switch tube, and a fourth switch tube;

[0015] The control end of the first switch tube is connected to the first input / output port in the MCU of the current CAN node, the first end of the first switch tube is connected to the current source, the second end of the first switch tube is connected to the first end of the second switch tube, and the current CAN node is any one of the at least two CAN nodes;

[0016] The control end of the second switch tube is connected to the second input / output port of the MCU of the CAN node, and the second end of the second switch tube is connected to the first end of the terminal resistor R1 of the CAN transceiver of the CAN node;

[0017] The control end of the third switch tube is connected to the third input / output port of the MCU of the CAN node, the first end of the third switch tube is connected to the second end of the terminal resistor R1, and the second end of the third switch tube is connected to the first end of the fourth switch tube;

[0018] The control end of the fourth switch tube is connected to the fourth input / output port of the MCU of the CAN node, and the second end of the fourth switch tube is connected to the “ground”;

[0019] The second end of the first switch tube or the first end of the second switch tube is connected to the first node P1 with the transmitting port of the CAN transceiver of the present CAN node, and the second end of the third switch tube or the first end of the fourth switch tube is connected to the receiving port of the CAN transceiver of the present CAN node, and the second node P2; or, the second end of the first switch tube or the first end of the second switch tube is connected to the receiving port of the CAN transceiver of the present CAN node, and the second end of the third switch tube or the first end of the fourth switch tube is connected to the transmitting port of the CAN transceiver of the present CAN node, and the first node P1;

[0020] The MCU of the present CAN node controls the passage between the first end and the second end of the first switch tube through the control end of the first switch tube, the MCU of the present CAN node controls the passage between the first end and the second end of the second switch tube through the control end of the second switch tube, the MCU of the present CAN node controls the passage between the first end and the second end of the third switch tube through the control end of the third switch tube, and the MCU of the present CAN node controls the passage between the first end and the second end of the fourth switch tube through the control end of the fourth switch tube.

[0021] A fourth aspect of the present application provides an electronic device, including:

[0022] Processor; and

[0023] The memory stores executable codes thereon, and when the executable codes are executed by the processor, the processor is caused to execute the method as described above.

[0024] A fifth aspect of the present application provides a computer-readable storage medium having executable code stored thereon. When the executable code is executed by a processor of an electronic device, the processor is caused to execute the method as described above.

[0025] The technical solution provided by the present application may have the following beneficial effects: when the resistance value of the external input and output of the CAN transceiver of the CAN node is obtained to be the preset resistance value R setWhen the MCU of other CAN nodes in the ACU is notified, the CAN transceiver of other CAN nodes configures the resistance value of the external input and output of the CAN transceiver to the preset resistance value R set The resistance of the CAN transceiver of this CAN node is R. Since the external input of the CAN transceiver of this CAN node is connected to the external input of the CAN transceiver of other CAN nodes, and the external output of the CAN transceiver of this CAN node is connected to the external output of the CAN transceiver of other CAN nodes, the resistance value of the external input and output of the CAN transceiver of this CAN node is R. set / 2, or a resistor with a preset resistance value R is mounted on the CAN node terminal resistance detection circuit set The resistance of the CAN node CAN transceiver is R set / N (where N is an integer not less than 3), the resistance value of the resistor mounted on the CAN node terminal resistance detection circuit is infinite through the CAN node terminal resistance detection circuit, thereby maintaining the current ACU having two CAN node CAN transceiver external inlet and outlet configurations and only configuring two resistor values ​​to be the preset resistance value R set That is, no matter how many CAN nodes the current ACU contains, it can ensure that the terminal resistance of the external entrance and exit of the CAN node of the ACU is accurately detected without human intervention, thereby meeting the configuration requirements of the terminal resistance of the external entrance and exit of the CAN node of the ACU.

[0026] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The above and other objects, features and advantages of the present application will become more apparent by describing in more detail exemplary embodiments of the present application in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments of the present application.

[0028] Figure 1 It is a flow chart of a CAN node terminal resistance management method shown in an embodiment of the present application;

[0029] Figure 2 It is an ACU network topology diagram of the CAN node configured with a CAN node terminal resistance detection circuit shown in the embodiment of the present application;

[0030] Figure 3 This application example shows Figure 2 The structure of the CAN node terminal resistance detection circuit configured in the CAN node in the example ACU network topology diagram and its connection relationship diagram with the MCU and CAN transceiver of the CAN node;

[0031] Figure 4Another embodiment of the present application shows Figure 2 The structure of the CAN node terminal resistance detection circuit configured in the CAN node in the example ACU network topology diagram and its connection relationship diagram with the MCU and CAN transceiver of the CAN node;

[0032] Figure 5 This application example shows Figure 2 The topology diagram of the ACU when the exemplary CAN node terminal resistance detection circuit includes a current source and four MOS tubes;

[0033] Figure 6 It is a structural schematic diagram of a CAN node terminal resistance management device shown in an embodiment of the present application;

[0034] Figure 7 It is a schematic diagram of the structure of a CAN node terminal resistance detection system shown in an embodiment of the present application;

[0035] Figure 8 It is a schematic diagram of the structure of an electronic device shown in an embodiment of the present application. DETAILED DESCRIPTION

[0036] The embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0037] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms of "a", "said" and "the" used in this application and the appended claims are also intended to include plural forms unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0038] It should be understood that although the terms "first", "second", "third", etc. may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of this application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0039] In the field of L3 / L4 autonomous driving, ACU, as an intelligent computing platform, can integrate computationally intensive sensor data processing and sensor fusion work with control strategy development into a control unit, and help to establish a structured and organized vehicle controller network. Generally speaking, ACU includes a network consisting of a microcontroller (MCU) and a controller area network (CAN) transceiver, where an MCU and a CAN transceiver can be classified as a CAN node of the network, and the CAN transceivers of the CAN nodes are interconnected through the CAN bus. According to the provisions of the CAN protocol on the physical layer, the two CAN transceivers on the CAN bus must be connected in series with a fixed resistance (for example, 120Ω) resistor (called "CAN node terminal resistor") at the external entrance and exit, and other CAN transceivers do not need to be connected in series with resistors. For ACU, in actual application, it is easy to miss soldering or solder an extra resistor at the external entrance and exit of the CAN transceiver. For example, in addition to connecting a terminal resistor in series at each of the two external entrances and exits of the ACU CAN transceiver, terminal resistors are also connected in series at other external entrances and exits of the CAN transceiver. Alternatively, only one external entrance and exit of the ACU CAN transceiver is connected in series with a terminal resistor, and no terminal resistor is connected in series at other external entrances and exits of the CAN transceiver. In order to detect the above errors, the relevant technology relies on files or documents, and the CAN nodes with incorrect series resistors are checked one by one manually according to the instructions of the files or documents. However, this method has significant shortcomings both in terms of efficiency and accuracy. For example, there are errors caused by carelessness during manual inspection, or it is easy to miss inspections when the network is complex and there are many CAN nodes, etc.

[0040] In response to the above problems, the embodiments of the present application provide a CAN node terminal resistance management method, device and CAN node terminal resistance detection circuit, which can automatically detect whether the terminal resistance of the external entrance and exit of the CAN node of the ACU is incorrectly welded, thereby improving detection efficiency and accuracy.

[0041] The technical solution of the embodiments of the present application is described in detail below with reference to the accompanying drawings.

[0042] See also Figure 1 , is a flow chart of a CAN node terminal resistance management method shown in an embodiment of the present application, which is applied to an autonomous driving domain controller ACU comprising at least two CAN nodes, each of the at least two CAN nodes comprising a microcontroller MCU and a CAN transceiver. Figure 1 The exemplary method mainly includes steps S101 to S104, which are described as follows:

[0043] Step S101: when the ACU is powered on, the resistance value of the external input and output of the CAN transceiver of the current CAN node is obtained through the CAN node terminal resistance detection circuit, wherein the current CAN node is any one CAN node of at least two CAN nodes.

[0044] In the embodiment of the present application, the external inlet and outlet of the CAN node CAN transceiver are relative to the two inlet and outlet connected to the MCU, that is, the external inlet and outlet of the CAN node CAN transceiver are the data input and output interfaces between the CAN transceiver and various sensor devices of the unmanned vehicle equipped with the ACU. For the convenience of description, any one of the at least two CAN nodes included in the ACU is named as the current CAN node, and the CAN node terminal resistance detection circuit can be configured in the current CAN node. Figure 2 As shown in FIG. 1 , this is the ACU network topology diagram of the CAN node configured with a CAN node terminal resistance detection circuit. Figure 3 Shows Figure 2 The structure of the CAN node terminal resistance detection circuit configured in this CAN node in the example ACU network topology diagram and its connection relationship with the MCU and CAN transceiver of this CAN node are explained below.

[0045] Figure 2 The CAN node terminal resistance detection circuit of the CAN node configuration in the example ACU network topology diagram mainly includes a current source 305, a first switch tube 301, a second switch tube 302, a third switch tube 303 and a fourth switch tube 304. Figure 3As shown. The control end of the first switch tube 301 is connected to the first input / output port (marked as 306 in the figure) in the MCU of the CAN node, the first end of the first switch tube 301 is connected to the current source 305, and the second end of the first switch tube 301 is connected to the first end of the second switch tube 302. The control end of the second switch tube 302 is connected to the second input / output port (marked as 307 in the figure) in the MCU of the CAN node, and the second end of the second switch tube 302 is connected to the first end of the terminal resistor R1 of the CAN transceiver of the CAN node. The control end of the third switch tube 303 is connected to the third input / output port (marked as 308 in the figure) in the MCU of the CAN node, the first end of the third switch tube 303 is connected to the second end of the terminal resistor R1, and the second end of the third switch tube 303 is connected to the first end of the fourth switch tube 304. The control end of the fourth switch tube 304 is connected to the fourth input / output port (marked as 309 in the figure) in the MCU of the CAN node, and the second end of the fourth switch tube 304 is connected to the "ground" (i.e., grounded). The second end of the first switch tube 301 or the first end of the second switch tube 302 is connected to the transmitting port of the CAN transceiver of the present CAN node at the first node P1, and the second end of the third switch tube 303 or the first end of the fourth switch tube 304 is connected to the receiving port of the CAN transceiver of the present CAN node at the second node P2, or, the second end of the first switch tube 301 or the first end of the second switch tube 302 is connected to the receiving port of the CAN transceiver of the present CAN node at the second node P2, and the second end of the third switch tube 303 or the first end of the fourth switch tube 304 is connected to the transmitting port of the CAN transceiver of the present CAN node at the first node P1.

[0046] When the ACU is powered on, i.e., when the ACU is initialized, the control end of the first switch tube 301 is turned on through the first input / output port 306 in the MCU of the CAN node, so that the path between the first end and the second end of the first switch tube 301 is connected, the control end of the second switch tube 302 is turned on through the second input / output port 307 in the MCU of the CAN node, so that the path between the first end and the second end of the second switch tube 302 is connected, the control end of the third switch tube 303 is turned on through the third input / output port 308 in the MCU of the CAN node, so that the path between the first end and the second end of the third switch tube 303 is connected, and the control end of the fourth switch tube 304 is turned on through the fourth input / output port 309 in the MCU of the CAN node, so that the path between the first end and the second end of the fourth switch tube 304 is connected, which means that the current source 305 can inject current into the first switch tube 301, the second switch tube 302, the terminal resistor R1, the third switch tube 303, and the fourth switch tube 304 (for example, when the current source 305 is a DC power supply, DC power can be injected). In this way, obtaining the resistance value of the external entrance and exit of the CAN transceiver of the present CAN node through the CAN node terminal resistance detection circuit can be: detecting the voltage between the first node P1 (i.e., the first end of the second switch tube 302 or the second end of the first switch tube 301) and the second node P2 (i.e., the second end of the third switch tube 303 or the first end of the fourth switch tube 304); obtaining the resistance value of the external entrance and exit of the CAN transceiver of the present CAN node according to the current provided by the current source 305 and the voltage between the first node P1 and the second node P2. For example, if the voltage between the first node P1 and the second node P2 is detected to be U1, and the current injected by the current source 305 to the first switch tube 301, the second switch tube 302, the terminal resistor R1, the third switch tube 303 and the fourth switch tube 304 is I1, then the resistance value of the external entrance and exit of the CAN transceiver of the present CAN node, i.e., the resistance value of the terminal resistor R1, is U1 / I1.

[0047] In one embodiment of the present application, Figure 3 The first switch tube 301, the second switch tube 302, the third switch tube 303 and the fourth switch tube 304 of the example can be P-channel MOS tubes, the control ends of the first switch tube 301, the second switch tube 302, the third switch tube 303 and the fourth switch tube 304 can be the gates of the P-channel MOS tubes, the first ends of the first switch tube 301, the second switch tube 302, the third switch tube 303 and the fourth switch tube 304 can be the sources of the P-channel MOS tubes, and the second ends of the first switch tube 301, the second switch tube 302, the third switch tube 303 and the fourth switch tube 304 can be the drains of the P-channel MOS tubes. Figure 4 Shows Figure 3When the first switch tube 301, the second switch tube 302, the third switch tube 303 and the fourth switch tube 304 are P-channel MOS tubes, the structure of the CAN node terminal resistance detection circuit configured by the CAN node and its connection relationship with the MCU and the CAN transceiver of the CAN node. Further, when the first switch tube 301, the second switch tube 302, the third switch tube 303 and the fourth switch tube 304 are P-channel MOS tubes, the method for controlling the conduction of the path between the source and the drain of each P-channel MOS tube can be to provide a level exceeding the threshold to the gate of each P-channel MOS tube through the input and output port of the MCU.

[0048] Step S102: If the resistance value of the external input and output of the CAN transceiver of the CAN node is the preset resistance value R set , then notify the MCU of other CAN nodes in the ACU to configure resistors at the external input and output of the CAN transceiver of other CAN nodes, where the external input of the CAN transceiver of this CAN node is connected to the external input of the CAN transceiver of other CAN nodes, and the external output of the CAN transceiver of this CAN node is connected to the external output of the CAN transceiver of other CAN nodes.

[0049] Figure 5 Shows Figure 2 The exemplary CAN node terminal resistance detection circuit includes a current source 305, a first switch tube 301, a second switch tube 302, a third switch tube 303 and a fourth switch tube 304, wherein the first switch tube 301, the second switch tube 302, the third switch tube 303 and the fourth switch tube 304 can be Figure 4 Example of a P-channel MOS tube. Figure 5 It can be seen that when the external inlet of the CAN transceiver of this CAN node is connected to the external inlet of the CAN transceiver of other CAN nodes, and the external outlet of the CAN transceiver of this CAN node is connected to the external outlet of the CAN transceiver of other CAN nodes, if each CAN node CAN transceiver external inlet is configured with or connected in series with terminal resistors, it means that these terminal resistors are parallel resistors. In the embodiment of the present application, according to the provisions of the CAN protocol on the physical layer, an ACU including at least two CAN nodes, wherein the external inlet of the CAN transceiver of the CAN node is either not configured with terminal resistors, or when configuring terminal resistors, the resistance value can only be configured with a preset resistance value R set (For example, 120Ω) terminal resistance, and a properly working ACU only allows two CAN nodes. The CAN transceiver has a preset resistance value R for the external input and output configuration. set If the resistance value of the CAN node CAN transceiver's external input and output is the preset resistance value R set, it means that the CAN transceiver of other CAN nodes needs to be configured with a resistor with a preset resistance value R set Therefore, when the resistance value of the CAN transceiver of the CAN node is detected to be the preset resistance value R set When the MCU of other CAN nodes in the ACU is notified, the MCU of other CAN nodes configures the resistors at the external input and output of the CAN transceiver of other CAN nodes.

[0050] Step S103: If the resistance value of the external input and output of the CAN transceiver of the CAN node is R set / 2, then the MCU of other CAN nodes is notified that there is no need to configure the resistance value of the CAN transceiver of other CAN nodes to the preset resistance value R set resistance.

[0051] As mentioned above, since the terminal resistors configured for the external inlet and outlet of the CAN node CAN transceiver of the ACU are parallel resistors, and a properly working ACU is only allowed to have two CAN nodes CAN transceivers configured with a preset resistance value R for the external inlet and outlet set Therefore, when detecting the resistance value of the CAN node CAN transceiver to the external input and output, it is R set / 2, it means that there are exactly two CAN nodes in the ACU. The CAN transceiver's external input and output are both configured with a resistor value of the preset resistance value R set The terminal resistance can be set to the preset resistance value R at the CAN transceiver of other CAN nodes. set It should be noted that in the above embodiment, there are exactly two CAN nodes in the ACU, and the CAN transceiver is configured with a resistor value of the preset resistance value R set The terminal resistance is either the CAN node CAN transceiver is configured with a preset resistance value R set The terminal resistance of the CAN transceiver of other CAN nodes is also configured with a preset resistance value R set The terminal resistance is either that the CAN transceiver of this CAN node has no terminal resistance configured for the outbound entry or that each CAN transceiver of the other two CAN nodes has a resistor with a preset resistance value R configured for the outbound entry. set The terminal resistance of

[0052] As mentioned above, the current source 305 mainly injects current into the first switch tube 301, the second switch tube 302, the terminal resistor R1, the third switch tube 303 and the fourth switch tube 304. After confirming that there are two CAN nodes in the ACU, the CAN transceiver's external input and output are configured with a resistor value of the preset resistance value R setThe terminal resistance of the current source 305 has been completed in the current node, and the detection of the terminal resistance of other CAN nodes does not require the current source 305 to provide current. Therefore, in the above embodiment, when notifying the MCU of other CAN nodes in the ACU, the CAN transceiver of other CAN nodes configures the resistance value of the external input and output of the CAN transceiver to be the preset resistance value R set After configuring the resistor or before notifying the MCU of other CAN nodes that there is no need to configure the resistor at the external entrance of the CAN transceiver of the other CAN nodes, the first switch tube and the fourth switch tube are disconnected and the second switch tube and the third switch tube are kept turned on.

[0053] Step S104: If the CAN node terminal resistance detection circuit is equipped with a resistance value of the preset resistance value R set The resistance of the CAN node CAN transceiver is R set / N, the resistance value of the resistor mounted on the CAN node terminal resistance detection circuit is made infinite through the CAN node terminal resistance detection circuit, where N is an integer not less than 3.

[0054] If the CAN node terminal resistance detection circuit is equipped with a resistor with a preset resistance value R set The resistance of the CAN transceiver of this CAN node is detected to be R set / N, where N is an integer not less than 3, it means that at least three CAN nodes in the ACU have CAN transceivers with external inputs and outputs configured with a resistor value of the preset resistance value R set For example, the resistance value of the CAN transceiver of the CAN node to the external input and output is R set / 3, indicating that there are three CAN nodes in the ACU. The CAN transceiver's external input and output are all configured with a resistor value of the preset resistance value R set For example, the resistance value of the CAN transceiver of the CAN node to the external input and output is R set / 4, indicating that there are four CAN nodes in the ACU. The CAN transceiver's external input and output are all configured with a resistor value of the preset resistance value R set The above situations do not meet the requirements of the ACU CAN node CAN transceiver for the external input and output resistance configuration, resulting in the ACU not being able to work properly. The CAN node terminal resistance detection circuit is mounted with a resistor with a preset resistance value R setIn the case of a resistance of , the resistance mounted on the CAN node terminal resistance detection circuit is a redundant terminal resistance, and therefore, the resistance value of the resistance mounted on the CAN node terminal resistance detection circuit can be infinite through the CAN node terminal resistance detection circuit. As for the specific method of making the resistance value of the resistance mounted on the CAN node terminal resistance detection circuit infinite through the CAN node terminal resistance detection circuit, it can be to open the control end of the second switch tube 302 through the second input / output port 307 in the MCU of the CAN node, so that the path between the first end and the second end of the second switch tube 302 is disconnected, and the control end of the third switch tube 303 is opened through the third input / output port 308 in the MCU of the CAN node, so that the path between the first end and the second end of the third switch tube 303 is disconnected, and the control end of the first switch tube 301 can be opened through the first input / output port 306 in the MCU of the CAN node, so that the path between the first end and the second end of the first switch tube 301 is disconnected, and the control end of the fourth switch tube 304 is opened through the fourth input / output port 309 in the MCU of the CAN node, so that the path between the first end and the second end of the fourth switch tube 304 is disconnected.

[0055] Furthermore, after the resistance value of the resistor mounted on the CAN node terminal resistance detection circuit is infinite through the CAN node terminal resistance detection circuit, if the resistance value of the external input and output of the CAN transceiver of the CAN node is detected to be R set / (N+1), for example, R set / 3, it means that the ACU has more than three CAN nodes. The CAN transceiver is configured with a preset resistance value R for the external input and output. set The terminal resistance of the CAN node terminal resistance detection circuit is not only a redundant terminal resistance, but also other CAN node CAN transceivers are configured with redundant terminal resistances for the external entrance and exit. Therefore, in addition to making the resistance value of the resistor mounted on the CAN node terminal resistance detection circuit infinite through the CAN node terminal resistance detection circuit, other actions may also be included, that is, after making the resistance value of the resistor mounted on the CAN node terminal resistance detection circuit infinite through the CAN node terminal resistance detection circuit, if the resistance value of the external entrance and exit of the CAN transceiver of this CAN node is R set / (N+1), then the MCU of other CAN nodes in the ACU is notified to detect the resistors mounted on the external inlet and outlet of the CAN transceiver of other CAN nodes, and when the resistance value of the resistors mounted on the external inlet and outlet of the CAN transceiver of other CAN nodes is detected, the resistance value is the preset resistance value R set It is required to remove the resistors mounted on the external input and output of the CAN transceiver of other CAN nodes.

[0056] From the above Figure 1The example CAN node terminal resistance management method shows that after obtaining the resistance value of the CAN transceiver of the CAN node to the external input and output is the preset resistance value R set When the MCU of other CAN nodes in the ACU is notified, the CAN transceiver of other CAN nodes configures the resistance value of the external input and output of the CAN transceiver to the preset resistance value R set The resistance of the CAN transceiver of this CAN node is R. Since the external input of the CAN transceiver of this CAN node is connected to the external input of the CAN transceiver of other CAN nodes, and the external output of the CAN transceiver of this CAN node is connected to the external output of the CAN transceiver of other CAN nodes, the resistance value of the external input and output of the CAN transceiver of this CAN node is R. set / 2, or a resistor with a preset resistance value R is mounted on the CAN node terminal resistance detection circuit set The resistance of the CAN node CAN transceiver is R set / N (where N is an integer not less than 3), the resistance value of the resistor mounted on the CAN node terminal resistance detection circuit is infinite through the CAN node terminal resistance detection circuit, thereby maintaining the current ACU having two CAN node CAN transceiver external inlet and outlet configurations and only configuring two resistor values ​​to be the preset resistance value R set That is, no matter how many CAN nodes the current ACU contains, it can ensure that the terminal resistance of the external entrance and exit of the CAN node of the ACU is accurately detected without human intervention, thereby meeting the configuration requirements of the terminal resistance of the external entrance and exit of the CAN node of the ACU.

[0057] Corresponding to the aforementioned application function implementation method embodiment, the present application also provides a CAN node terminal resistance management device, electronic device and corresponding embodiments.

[0058] See also Figure 6 , is a schematic diagram of the structure of a CAN node terminal resistance management device shown in an embodiment of the present application. For ease of description, only the parts related to the embodiment of the present application are shown. Figure 6 The exemplary CAN node terminal resistance management device can be applied to an autonomous driving domain controller ACU including at least two CAN nodes, each of the at least two CAN nodes including a microcontroller MCU and a CAN transceiver. Figure 6 The exemplary CAN node terminal resistance management device mainly includes an acquisition module 601, a first notification module 602, a second notification module 603 and an enabling module 604, wherein:

[0059] The acquisition module 601 is used to acquire the resistance value of the external input and output of the CAN transceiver of the current CAN node through the CAN node terminal resistance detection circuit when the ACU is powered on, wherein the current CAN node is any one of the at least two CAN nodes;

[0060] The first notification module 602 is used to notify the user if the resistance value of the external input and output of the CAN transceiver of the CAN node is the preset resistance value R set , then the MCU of other CAN nodes in the ACU is notified to configure the resistance value of the CAN transceiver of other CAN nodes to the preset resistance value R set The resistance of the CAN transceiver of the present CAN node is connected to the external input of the CAN transceiver of other CAN nodes, and the external output of the CAN transceiver of the present CAN node is connected to the external output of the CAN transceiver of other CAN nodes;

[0061] The second notification module 603 is used to notify the user if the resistance value of the external input and output of the CAN transceiver of the CAN node is R set / 2, then the MCU of other CAN nodes is notified that there is no need to configure resistors at the external input and output of the CAN transceiver of the other CAN nodes;

[0062] The enabling module 604 is used to enable the CAN node terminal resistance detection circuit to detect the resistance value of the resistor R set The resistance of the CAN node CAN transceiver is R set / N, the resistance value of the resistor mounted on the CAN node terminal resistance detection circuit is made infinite through the CAN node terminal resistance detection circuit, where N is an integer not less than 3.

[0063] Regarding the device in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated again here.

[0064] See also Figure 7 The present application also provides a CAN node terminal resistance detection system. For ease of description, only the parts related to the present application are shown. Figure 7 The system includes Figure 3 In addition to the exemplary CAN node terminal resistance detection circuit, the MCU 701 and the CAN transceiver 702 are also included. Figure 3In the example, the MCU of the CAN node controls the passage between the first end and the second end of the first switch tube 301 through the control end of the first switch tube 301, the MCU of the CAN node controls the passage between the first end and the second end of the second switch tube 302 through the control end of the second switch tube 302, the MCU of the CAN node controls the passage between the first end and the second end of the third switch tube 303 through the control end of the third switch tube 303, and the MCU of the CAN node controls the passage between the first end and the second end of the fourth switch tube 304 through the control end of the fourth switch tube 304. Figure 7 In the exemplary system, the MCU 701 of the CAN node controls the passage between the first end and the second end of the first switch tube 301 through the control end of the first switch tube 301, the MCU 701 of the CAN node controls the passage between the first end and the second end of the second switch tube 302 through the control end of the second switch tube 302, the MCU 701 of the CAN node controls the passage between the first end and the second end of the third switch tube 303 through the control end of the third switch tube 303, and the MCU 701 of the CAN node controls the passage between the first end and the second end of the fourth switch tube 304 through the control end of the fourth switch tube 304. In one embodiment, Figure 7 In the example system, the first switch tube 301, the second switch tube 302, the third switch tube 303 and the fourth switch tube 304 can be P-channel MOS tubes, the control ends of the first switch tube 301, the second switch tube 302, the third switch tube 303 and the fourth switch tube 304 can be the gates of the P-channel MOS tubes, the first ends of the first switch tube 301, the second switch tube 302, the third switch tube 303 and the fourth switch tube 304 can be the sources of the P-channel MOS tubes, and the first switch tube 301, the second switch tube 302, the third switch tube 303 and the fourth switch tube 304 can be the drains of the P-channel MOS tubes.

[0065] Figure 8 It is a schematic diagram of the structure of an electronic device shown in an embodiment of the present application.

[0066] See also Figure 8 , the electronic device 800 includes a memory 810 and a processor 820.

[0067] The processor 820 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or the processor may be any conventional processor, etc.

[0068] The memory 810 may include various types of storage units, such as system memory, read-only memory (ROM), and permanent storage. Among them, ROM can store static data or instructions required by the processor 820 or other modules of the computer. The permanent storage device may be a readable and writable storage device. The permanent storage device may be a non-volatile storage device that does not lose the stored instructions and data even after the computer is powered off. In some embodiments, the permanent storage device uses a large-capacity storage device (such as a magnetic or optical disk, flash memory) as a permanent storage device. In some other embodiments, the permanent storage device may be a removable storage device (such as a floppy disk, optical drive). The system memory may be a readable and writable storage device or a volatile readable and writable storage device, such as a dynamic random access memory. The system memory may store some or all instructions and data required by the processor at run time. In addition, the memory 810 may include any combination of computer-readable storage media, including various types of semiconductor storage chips (such as DRAM, SRAM, SDRAM, flash memory, programmable read-only memory), and disks and / or optical disks may also be used. In some embodiments, the memory 810 may include a readable and / or writable removable storage device, such as a laser disc (CD), a read-only digital versatile disc (e.g., DVD-ROM, double-layer DVD-ROM), a read-only Blu-ray disc, an ultra-density optical disc, a flash memory card (e.g., SD card, mini SD card, Micro-SD card, etc.), a magnetic floppy disk, etc. The computer-readable storage medium does not include carrier waves and transient electronic signals transmitted wirelessly or wired.

[0069] The memory 810 stores executable codes, and when the executable codes are processed by the processor 820 , the processor 820 can execute part or all of the methods described above.

[0070] In addition, the method according to the present application may also be implemented as a computer program or a computer program product, which includes computer program code instructions for executing some or all of the steps in the above method of the present application.

[0071] Alternatively, the present application can also be implemented as a computer-readable storage medium (or non-transitory machine-readable storage medium or machine-readable storage medium) on which executable code (or computer program or computer instruction code) is stored. When the executable code (or computer program or computer instruction code) is executed by a processor of an electronic device (or server, etc.), the processor executes part or all of the steps of the above-mentioned method according to the present application.

[0072] The embodiments of the present application have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A CAN node terminal resistance management method is applied to an autonomous driving domain controller ACU comprising at least two CAN nodes, wherein each of the at least two CAN nodes comprises a microcontroller MCU and a CAN transceiver, characterized in that: The method comprises: When the ACU is powered on, the resistance value of the external input and output of the CAN transceiver of the current CAN node is obtained through the CAN node terminal resistance detection circuit, and the current CAN node is any one of the at least two CAN nodes; If the resistance value of the external input and output of the CAN transceiver of the CAN node is the preset resistance value R set , then notify the MCU of other CAN nodes in the ACU to configure the resistance value of the CAN transceiver of the other CAN nodes to be the preset resistance value R set The external input of the CAN transceiver of the CAN node is connected to the external input of the CAN transceiver of the other CAN nodes, and the external output of the CAN transceiver of the CAN node is connected to the external output of the CAN transceiver of the other CAN nodes; If the resistance value of the CAN node CAN transceiver to the external input and output is R set / 2, then notify the MCU of the other CAN nodes that there is no need to configure resistors at the external inlet and outlet of the CAN transceiver of the other CAN nodes; If the CAN node terminal resistance detection circuit is mounted with a resistance value of the preset resistance value R set The resistance of the CAN node CAN transceiver is R set / N, then the resistance value of the resistor mounted on the CAN node terminal resistance detection circuit is made infinite through the CAN node terminal resistance detection circuit, and N is an integer not less than 3.

2. The CAN node terminal resistance management method according to claim 1, characterized in that: The CAN node terminal resistance detection circuit includes a current source, a first switch tube, a second switch tube, a third switch tube and a fourth switch tube; The control end of the first switch tube is connected to the first input / output port of the MCU of the CAN node, the first end of the first switch tube is connected to the current source, and the second end of the first switch tube is connected to the first end of the second switch tube; The control end of the second switch tube is connected to the second input / output port of the MCU of the CAN node, and the second end of the second switch tube is connected to the first end of the terminal resistor R1 of the CAN transceiver of the CAN node; The control end of the third switch tube is connected to the third input / output port of the MCU of the CAN node, the first end of the third switch tube is connected to the second end of the terminal resistor R1, and the second end of the third switch tube is connected to the first end of the fourth switch tube; The control end of the fourth switch tube is connected to the fourth input / output port of the MCU of the CAN node, and the second end of the fourth switch tube is connected to the "ground"; The second end of the first switch tube or the first end of the second switch tube is connected to the transmitting port of the CAN transceiver of the present CAN node at the first node P1, and the second end of the third switch tube or the first end of the fourth switch tube is connected to the receiving port of the CAN transceiver of the present CAN node at the second node P2; or, the second end of the first switch tube or the first end of the second switch tube is connected to the receiving port of the CAN transceiver of the present CAN node at the second node P2, and the second end of the third switch tube or the first end of the fourth switch tube is connected to the transmitting port of the CAN transceiver of the present CAN node at the first node P1.

3. The CAN node terminal resistance management method according to claim 2, characterized in that: The first switch tube, the second switch tube, the third switch tube and the fourth switch tube are P-channel MOS tubes, the control ends of the first switch tube, the second switch tube, the third switch tube and the fourth switch tube are gates of the P-channel MOS tubes, the first ends of the first switch tube, the second switch tube, the third switch tube and the fourth switch tube are sources of the P-channel MOS tubes, and the second ends of the first switch tube, the second switch tube, the third switch tube and the fourth switch tube are drains of the P-channel MOS tubes.

4. The CAN node terminal resistance management method according to claim 2, characterized in that: The step of obtaining the resistance value of the external entrance and exit of the CAN transceiver of the CAN node through the CAN node terminal resistance detection circuit includes: detecting a voltage between the first node P1 and the second node P2; According to the current provided by the current source and the voltage between the first node P1 and the second node P2, the resistance value of the external input and output of the CAN transceiver of the CAN node is obtained.

5. The CAN node terminal resistance management method according to claim 2, characterized in that: The method further comprises: The MCU of other CAN nodes in the ACU is notified to configure the resistance value of the preset resistance value R at the external input and output of the CAN transceiver of the other CAN nodes. set After configuring the resistor or before notifying the MCU of the other CAN nodes that there is no need to configure the resistor at the external entrance of the CAN transceiver of the other CAN nodes, the first switch tube and the fourth switch tube are disconnected and the second switch tube and the third switch tube are kept turned on.

6. The CAN node terminal resistance management method according to any one of claims 1 to 5, characterized in that: The method further comprises: After the resistance value of the resistor mounted on the CAN node terminal resistance detection circuit is infinite through the CAN node terminal resistance detection circuit, if the resistance value of the external input and output of the CAN transceiver of the CAN node is R set / (N+1), then notify the MCU of other CAN nodes in the ACU to detect the resistor mounted on the external inlet and outlet of the CAN transceiver of the other CAN node, and when the resistance value of the resistor mounted on the external inlet and outlet of the CAN transceiver of the other CAN node is detected, the preset resistance value R is set. set It is required to remove the resistor mounted on the external input and output of the CAN transceiver of the other CAN nodes.

7. A CAN node terminal resistance management device, applied to an autonomous driving domain controller ACU comprising at least two CAN nodes, each of the at least two CAN nodes comprising a microcontroller MCU and a CAN transceiver, characterized in that: The device comprises: an acquisition module, configured to acquire the resistance value of the external inlet and outlet of the CAN transceiver of the current CAN node through the CAN node terminal resistance detection circuit when the ACU is powered on, wherein the current CAN node is any one of the at least two CAN nodes; The first notification module is used to notify the user if the resistance value of the external input and output of the CAN transceiver of the CAN node is a preset resistance value R set , then notify the MCU of other CAN nodes in the ACU to configure the resistance value of the CAN transceiver of the other CAN nodes to be the preset resistance value R set The external input of the CAN transceiver of the CAN node is connected to the external input of the CAN transceiver of the other CAN nodes, and the external output of the CAN transceiver of the CAN node is connected to the external output of the CAN transceiver of the other CAN nodes; The second notification module is used to notify the user if the resistance value of the external input and output of the CAN transceiver of the CAN node is R set / 2, then notify the MCU of the other CAN nodes that there is no need to configure resistors at the external inlet and outlet of the CAN transceiver of the other CAN nodes; The enabling module is used to enable the CAN node terminal resistance detection circuit to mount a resistor with a preset resistance value R set The resistance of the CAN node CAN transceiver is R set / N, then the resistance value of the resistor mounted on the CAN node terminal resistance detection circuit is made infinite through the CAN node terminal resistance detection circuit, and N is an integer not less than 3.

8. A CAN node terminal resistance detection circuit, applied to an autonomous driving domain controller ACU comprising at least two CAN nodes, each of the at least two CAN nodes comprising a microcontroller MCU and a CAN transceiver, characterized in that: The CAN node terminal resistance detection circuit includes a current source, a first switch tube, a second switch tube, a third switch tube and a fourth switch tube; The control end of the first switch tube is connected to the first input / output port in the MCU of the current CAN node, the first end of the first switch tube is connected to the current source, the second end of the first switch tube is connected to the first end of the second switch tube, and the current CAN node is any one of the at least two CAN nodes; The control end of the second switch tube is connected to the second input / output port of the MCU of the CAN node, and the second end of the second switch tube is connected to the first end of the terminal resistor R1 of the CAN transceiver of the CAN node; The control end of the third switch tube is connected to the third input / output port of the MCU of the CAN node, the first end of the third switch tube is connected to the second end of the terminal resistor R1, and the second end of the third switch tube is connected to the first end of the fourth switch tube; The control end of the fourth switch tube is connected to the fourth input / output port of the MCU of the CAN node, and the second end of the fourth switch tube is connected to the "ground"; The second end of the first switch tube or the first end of the second switch tube is connected to the first node P1 with the transmitting port of the CAN transceiver of the present CAN node, and the second end of the third switch tube or the first end of the fourth switch tube is connected to the receiving port of the CAN transceiver of the present CAN node, and the second node P2; or, the second end of the first switch tube or the first end of the second switch tube is connected to the receiving port of the CAN transceiver of the present CAN node, and the second end of the third switch tube or the first end of the fourth switch tube is connected to the transmitting port of the CAN transceiver of the present CAN node, and the first node P1; The MCU of the present CAN node controls the passage between the first end and the second end of the first switch tube through the control end of the first switch tube, the MCU of the present CAN node controls the passage between the first end and the second end of the second switch tube through the control end of the second switch tube, the MCU of the present CAN node controls the passage between the first end and the second end of the third switch tube through the control end of the third switch tube, and the MCU of the present CAN node controls the passage between the first end and the second end of the fourth switch tube through the control end of the fourth switch tube.

9. An electronic device, characterized in that: include: processor; as well as A memory having executable codes stored thereon, which, when executed by the processor, causes the processor to execute the method according to any one of claims 1 to 6.

10. A computer-readable storage medium having executable codes stored thereon, which, when executed by a processor of an electronic device, causes the processor to execute the method according to any one of claims 1 to 6.

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