Impedance matching circuit, bus network system and impedance matching method

Abstract

The invention discloses an impedance matching circuit, a bus network system and an impedance matching method. The impedance matching circuit comprises a signal transmission unit, a wiring terminal, a terminal resistor and an impedance matching unit, the first end of the signal transmission unit is suitable for being connected with a controller. The wiring terminals comprise a first wiring terminal, a second wiring terminal, a third wiring terminal and a fourth wiring terminal, the first wiring terminal is connected with the second end of the signal transmission unit and is connected with the first bus, and the second wiring terminal is connected with the third end of the signal transmission unit and one end of the third wiring terminal and is connected with the second bus; one end of the terminal resistor is connected with one end of the first wiring terminal and the second end of the signal transmission unit, and the other end of the terminal resistor is connected with one end of the fourth wiring terminal; the impedance matching unit is configured to control the connection state between the third wiring terminal and the fourth wiring terminal according to the position information of the controller, so that the terminal resistor is connected between the first bus and the second bus.

Description

Technical Field

[0001] The present application belongs to the technical field of electronic circuits, and specifically relates to an impedance matching circuit, a bus network system, and an impedance matching method. Background Art

[0002] Currently, with the increasing complexity of automotive electronic architecture, the number and integration of on-board controllers (especially domain controllers) have increased significantly. Due to the differences in layout requirements of different vehicle platforms, the same controller may require different designs in the configuration of terminal resistors due to factors such as installation location, peripheral controller configuration, or platform compatibility restrictions. For example, some application scenarios require the controller to be configured with terminal resistors to meet signal integrity or anti-interference requirements, while other scenarios may not require the configuration of terminal resistors due to differences in system architecture or wiring.

[0003] However, users' demand for flexible terminal resistor configurations leads to multiple versions of the same controller hardware, depending on whether or not the terminal resistors are configured. This further complicates hardware design, production, and material management. Related technologies typically design different hardware variants to meet different requirements. This design approach can lead to assembly errors and compatibility issues due to improper version management. Summary of the Invention

[0004] The present invention aims to at least partially address one of the technical problems in the related art. To this end, the present application proposes an impedance matching circuit, a bus network system, and an impedance matching method. By matching the terminal resistance of a controller through the impedance matching circuit, the same controller can be adapted to different vehicle models or platforms. Therefore, the hardware circuits of all controllers can remain consistent, eliminating the need for multiple controller part numbers to be managed, thereby effectively reducing the number of controller product variants and improving platform compatibility.

[0005] In a first aspect, an embodiment of the present application provides an impedance matching circuit, comprising: a signal transmission unit, a wiring terminal, a terminal resistor, and an impedance matching unit.

[0006] The first end of the signal transmission unit is suitable for connecting to a controller; the wiring terminal includes a first wiring terminal, a second wiring terminal, a third wiring terminal and a fourth wiring terminal, one end of the first wiring terminal is connected to the second end of the signal transmission unit, and the other end of the first wiring terminal is suitable for connecting to a first bus, one end of the second wiring terminal is respectively connected to the third end of the signal transmission unit and one end of the third wiring terminal, and the other end of the second wiring terminal is suitable for connecting to a second bus;

[0007] One end of the terminal resistor is connected to one end of the first wiring terminal and the second end of the signal transmission unit respectively, and the other end of the terminal resistor is connected to one end of the fourth wiring terminal;

[0008] The impedance matching unit is configured to control a connection state between the third terminal and the fourth terminal according to position information of the controller, so that the terminal resistor is connected between the first bus and the second bus.

[0009] In some embodiments, the impedance matching unit is further configured to, when it is determined based on the position information that the controller needs to be configured with a terminal resistor, connect the third terminal and the fourth terminal so that the terminal resistor is connected between the first bus and the second bus; or, when it is determined based on the position information that the controller does not need to be configured with a terminal resistor, disconnect the third terminal and the fourth terminal.

[0010] In some embodiments, the impedance matching unit includes: a controllable switch and a control module; wherein,

[0011] One end of the controllable switch is connected to the other end of the third terminal, and the other end of the controllable switch is connected to the other end of the fourth terminal;

[0012] The control module is connected to the controllable switch, and is configured to perform on-off control on the controllable switch according to the position information, so that the controllable switch controls the connection state between the third terminal and the fourth terminal.

[0013] In some embodiments, the terminal resistor includes a first terminal resistor and a second terminal resistor, wherein the first terminal resistor and the second terminal resistor are connected in series and arranged between one end of the first terminal and the other end of the fourth terminal.

[0014] In some embodiments, the system further includes: a filtering unit, which is connected to one end of the first terminal and one end of the second terminal respectively, and is configured to filter the electrical signals on the first bus and the second bus.

[0015] In some embodiments, the filtering unit includes: a first filter capacitor, a second filter capacitor and a third filter capacitor; wherein, one end of the first filter capacitor is connected to one end of the first terminal, and the other end of the first filter capacitor is grounded; one end of the second filter capacitor is grounded, and the other end of the second filter capacitor is connected to one end of the second terminal; one end of the third filter capacitor is connected to the connection point of the first terminal resistor and the second terminal resistor, and the other end of the third filter capacitor is grounded.

[0016] In some embodiments, the system further includes: a protection unit, which is disposed between one end of the first wiring terminal and one end of the second wiring terminal, and is configured to provide overvoltage protection for the first bus and the second bus.

[0017] In some embodiments, the protection unit includes: a first reverse diode and a second reverse diode; wherein,

[0018] One end of the first reverse diode is connected to one end of the first terminal; one end of the second reverse diode is connected to the other end of the first reverse diode and is grounded, and the other end of the second reverse diode is connected to one end of the second terminal.

[0019] An embodiment of the present application also provides a bus network system, comprising: at least one impedance matching circuit and at least one controller; wherein each impedance matching circuit is suitable for connecting a first bus and a second bus and is connected to a controller, and each impedance matching circuit is configured to perform impedance matching on the corresponding controller based on position information of the corresponding controller.

[0020] An embodiment of the present application further provides an impedance matching method, which is applied to an impedance matching circuit. The impedance matching circuit includes: a signal transmission unit, a wiring terminal, a terminal resistor, and an impedance matching unit. The first end of the signal transmission unit is suitable for connecting to a controller. The wiring terminal includes a first wiring terminal, a second wiring terminal, a third wiring terminal, and a fourth wiring terminal. One end of the first wiring terminal is connected to the second end of the signal transmission unit, and the other end of the first wiring terminal is suitable for connecting to a first bus. One end of the second wiring terminal is respectively connected to the third end of the signal transmission unit and one end of the third wiring terminal. The other end of the second wiring terminal is suitable for connecting to a second bus. One end of the terminal resistor is respectively connected to one end of the first wiring terminal and the second end of the signal transmission unit, and the other end of the terminal resistor is connected to one end of the fourth wiring terminal. The method includes:

[0021] The connection state between the third wiring terminal and the fourth wiring terminal is controlled according to the position information of the controller, so that the terminal resistor is connected between the first bus and the second bus.

[0022] The impedance matching circuit provided in the present application matches the terminal resistance of the controller through the impedance matching circuit by setting configurable terminals (first terminal, second terminal, third terminal, fourth terminal) and terminal resistance connection method, so that the same controller can be adapted to different vehicle models or platforms. Therefore, the hardware circuits of all controllers can be kept consistent, and there is no need to manage the part numbers of multiple controllers, thereby effectively reducing the number of variants of controller products to improve platform compatibility.

[0023] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of the structure of an impedance matching circuit provided in an embodiment of the present application;

[0025] Figure 2 A schematic structural diagram of an impedance matching unit provided in an embodiment of the present application;

[0026] Figure 3 A circuit diagram of a terminal resistor provided in an embodiment of the present application;

[0027] Figure 4 A circuit diagram of a filter unit provided in an embodiment of the present application;

[0028] Figure 5 A circuit diagram of a protection unit provided in an embodiment of the present application;

[0029] Figure 6 A circuit diagram of an impedance matching circuit provided in an embodiment of the present application;

[0030] Figure 7 A schematic diagram of the structure of a bus network system provided in an embodiment of the present application;

[0031] Figure 8 A flowchart of an impedance matching method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0032] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0033] Currently, with the increasing complexity of automotive electronic architecture, the number and integration of on-board controllers (especially domain controllers) have increased significantly. Due to the differences in layout requirements of different vehicle platforms, the same controller may require different designs in the configuration of terminal resistors due to factors such as installation location, peripheral controller configuration, or platform compatibility restrictions. For example, some application scenarios require the controller to be configured with terminal resistors to meet signal integrity or anti-interference requirements, while other scenarios may not require the configuration of terminal resistors due to differences in system architecture or wiring.

[0034] However, users' demand for flexible terminal resistor configurations leads to multiple versions of the same controller hardware, depending on whether or not the terminal resistors are configured. This further complicates hardware design, production, and material management. Existing technologies typically design different hardware variants to accommodate different requirements. This approach not only increases development costs but can also lead to assembly errors and compatibility issues due to improper version management.

[0035] Therefore, there is an urgent need for an on-board controller design solution that can flexibly adapt to the terminal resistance configuration requirements to reduce the number of hardware variants and improve versatility.

[0036] The impedance matching circuit, bus network system, and impedance matching method according to embodiments of the present invention are described below with reference to the accompanying drawings.

[0037] Figure 1 A schematic diagram of an impedance matching circuit is provided in an embodiment of the present application. Figure 1 As shown, the impedance matching circuit 100 includes: a signal transmission unit 10 , a connection terminal, a terminal resistor 20 and an impedance matching unit 30 .

[0038] Among them, the first end of the signal transmission unit 10 is suitable for connecting to the controller 200; the wiring terminals include a first wiring terminal PIN1, a second wiring terminal PIN2, a third wiring terminal PIN3 and a fourth wiring terminal PIN4, one end of the first wiring terminal PIN1 is connected to the second end of the signal transmission unit 10, and the other end of the first wiring terminal PIN1 is suitable for connecting to the first bus CAN_H, one end of the second wiring terminal PIN2 is respectively connected to the third end of the signal transmission unit 10 and one end of the third wiring terminal PIN3, and the other end of the second wiring terminal PIN2 is suitable for connecting to the second bus CAN_L; one end of the terminal resistor 20 is respectively connected to one end of the first wiring terminal PIN1 and the second end of the signal transmission unit 10, and the other end of the terminal resistor 20 is connected to one end of the fourth wiring terminal PIN4; the impedance matching unit 30 is configured to control the connection state between the third wiring terminal PIN3 and the fourth wiring terminal PIN4 according to the position information of the controller 200, so that the terminal resistor 20 is connected between the first bus CAN_H and the second bus CAN_L.

[0039] Specifically, the signal transmission unit 10 is used to exchange data between the controller 200 and the first bus CAN_H and the second bus CAN_L. Specifically, the signal transmission unit 10 receives data from the first bus CAN_H and the second bus CAN_L and forwards the data to the controller 200. It also transmits data sent by the controller 200 to the first bus CAN_H and the second bus CAN_L. The signal transmission unit 10 is connected to the first bus CAN_H and the second bus CAN_L via the first terminal PIN1 and the second terminal PIN2, respectively. The connection status between the third terminal PIN3 and the fourth terminal PIN4 is used to control whether the controller 200 is configured with the terminal resistor 20. By default, the controller 200 is not configured with the terminal resistor 20. The position of the controller 200 is set by the manufacturer based on actual conditions. If the impedance matching unit 30 determines that the terminal resistor 20 is required based on the position information, it controls the connection status between the third terminal PIN3 and the fourth terminal PIN4 to connect the terminal resistor 20 between the first bus CAN_H and the second bus CAN_L. Therefore, the manufacturer does not need to adjust the hardware circuit of the controller 200 according to the controller position, so there are no multiple versions of the controller 200, and therefore, there is no need to set multiple controller part numbers to manage the controller 200.

[0040] In an optional implementation, the controller 200 may be a MCU (Microcontroller Unit), but is not limited to an MCU and may also be other types of controllers, which are not specifically limited here.

[0041] In the above embodiment, the terminal resistance of the controller is matched through an impedance matching circuit, so that the same controller can be adapted to different vehicle models or platforms. Therefore, the hardware circuits of all controllers can remain consistent, and there is no need to manage the part numbers of multiple controllers, which can effectively reduce the number of variants of controller products and improve platform compatibility.

[0042] Further, such as Figure 1 As shown, in some embodiments, the first bus CAN_H is a CANH communication line, and the second bus CAN_L is a CANL communication line.

[0043] That is, the bus in this embodiment is a CAN (Controller Area Network) bus, and the voltage values ​​of the first bus CAN_H and the second bus CAN_L are different, so the first bus CAN_H and the second bus CAN_L will generate differential signals, thereby realizing signal transmission.

[0044] In an optional embodiment, as Figure 2 As shown, the signal transmission unit 10 includes a CAN transceiver 11, the Rx pin of the CAN transceiver 11 is suitable for connecting to the first end of the controller 200, the Tx pin of the CAN transceiver 11 is suitable for connecting to the second end of the controller 200, the CAN_H pin of the CAN transceiver 11 is connected to the first terminal PIN1, and the CAN_L pin of the CAN transceiver 11 is connected to the second terminal PIN2.

[0045] In some embodiments, the impedance matching unit 30 is further configured to connect the third terminal PIN3 and the fourth terminal PIN4 when it is determined based on the position information that the controller 200 needs to be configured with the terminal resistor 20, so that the terminal resistor 20 is connected between the first bus CAN_H and the second bus CAN_L; or, when it is determined based on the position information that the controller 200 does not need to be configured with the terminal resistor 20, disconnect the third terminal PIN3 and the fourth terminal PIN4.

[0046] Specifically, when the controller 200 needs to be configured with the terminal resistor 20, the impedance matching unit 30 connects the third terminal PIN3 and the fourth terminal PIN4. After the third terminal PIN3 and the fourth terminal PIN4 are connected, the first bus CAN_H is connected to one end of the terminal resistor 20 through the first terminal PIN1, the second terminal PIN2, the third terminal PIN3 and the fourth terminal PIN4 form a path, and the second bus CAN_L is connected to the other end of the terminal resistor 20. Therefore, the terminal resistor 20 is connected between the first bus CAN_H and the second bus CAN_L to achieve impedance matching with the cable and reduce signal reflection at the transmission terminal; when the controller 200 does not need to be configured with the terminal resistor 20, the impedance matching unit 30 disconnects the third terminal PIN3 and the fourth terminal PIN4, and the third terminal PIN3 and the fourth terminal PIN4 are in a floating state. The first bus CAN_H is connected to the signal transmission unit 10 through the first terminal PIN1, and the second bus CAN_L is connected to the signal transmission unit 10 through the second terminal PIN2. The terminal resistor 20 is not connected between the first bus CAN_H and the second bus CAN_L.

[0047] It should be noted that the connection status between the third terminal PIN3 and the fourth terminal PIN4 can also be manually controlled. The user can directly short-circuit the third terminal PIN3 and the fourth terminal PIN4 at the wiring harness end to connect the third terminal PIN3 and the fourth terminal PIN4. This configuration allows the terminal resistor 20 to be configured entirely at the wiring harness end, eliminating the need to adjust the internal circuitry of the controller 200, simplifying the production process and thereby reducing the manufacturing cost of the controller 200 production line.

[0048] In the above embodiment, the impedance matching unit intelligently determines whether the terminal resistor needs to be configured based on the location information of the controller (such as the installation location, system architecture or communication protocol requirements), and automatically controls the on-off status of the third terminal and the fourth terminal to achieve flexible connection or disconnection of the terminal resistor, so that the same hardware design can adapt to the terminal resistor configuration requirements of different vehicle models or platforms, without the need to develop multiple hardware versions, significantly reducing development and production costs.

[0049] In some embodiments, as Figure 2As shown, the impedance matching unit 30 includes: a controllable switch 31 and a control module 32; wherein, one end of the controllable switch 31 is connected to the other end of the third terminal PIN3, and the other end of the controllable switch 31 is connected to the other end of the fourth terminal PIN4; the control module 32 is connected to the controllable switch 31, and the control module 32 is configured to control the controllable switch 31 according to the position information, so that the controllable switch 31 controls the connection state between the third terminal PIN3 and the fourth terminal PIN4.

[0050] Specifically, when the controller 200 needs to configure the terminal resistor 20, the control module 32 controls the controllable switch 31 to be turned on so that the third terminal PIN3 and the fourth terminal PIN4 are connected; when the controller 200 does not need to be configured with the terminal resistor 20, the control module 32 controls the controllable switch 31 to be turned off so that the third terminal PIN3 and the fourth terminal PIN4 are suspended.

[0051] It should be noted that the controllable switch 31 can be a switching tube, such as a triode or a MOS (Metal-Oxide-Semiconductor Field-Effect Transistor). When the controller 200 needs to be configured with the terminal resistor 20, the control module 32 outputs a first control signal to the switching tube to turn on the switching tube. When the controller 200 does not need to be configured with the terminal resistor 20, the control module 32 outputs a second control signal to the switching tube to turn off the switching tube.

[0052] In an embodiment of the present application, the configuration of the terminal resistance is completely automatically completed by the impedance matching unit, without the need for manual jumpers or external intervention, which can reduce the risk of assembly errors and improve production consistency. In addition, the present application can adjust the terminal resistance state through software or logical configuration (such as position information) without the need for hardware changes, which is convenient for adapting to future architecture upgrades or new vehicle model requirements and can reduce maintenance costs. In addition, the unification of hardware versions can reduce the variety of materials and the difficulty of inventory management, thereby avoiding mismatch problems caused by differences in terminal resistance configuration. Furthermore, this setting method can avoid manual misoperation (such as missing terminal resistance).

[0053] In some embodiments, as Figure 3 As shown, the terminal resistor 20 includes a first terminal resistor R1 and a second terminal resistor R2, wherein the first terminal resistor R1 and the second terminal resistor R2 are connected in series and arranged between one end of the first terminal PIN1 and the other end of the fourth terminal PIN4.

[0054] Specifically, the resistance range of the first terminal resistor R1 is [55Ω, 62Ω]; the resistance range of the second terminal resistor R2 is [55Ω, 62Ω]. For example, in one example, the resistance of the first terminal resistor R1 is 60Ω, and the resistance of the second terminal resistor R2 is 60Ω. The resistance of the first terminal resistor R1 and the second terminal resistor R2 in series is 120Ω, which can accurately match the characteristic impedance of the CAN bus of 120Ω.

[0055] The present application uses a first terminal resistor and a second terminal resistor connected in series to effectively reduce the interference of the external environment on the differential signal of the first bus and the second bus, thereby improving the signal quality and ensuring the reliability of data transmission.

[0056] In some embodiments, as Figure 4 As shown, the impedance matching circuit 100 further includes: a filtering unit 40, which is connected to one end of the first terminal PIN1 and one end of the second terminal PIN2 respectively, and is configured to filter the electrical signals on the first bus CAN_H and the second bus CAN_L.

[0057] It is understandable that the first bus CAN_H and the second bus CAN_L are affected by the external environment and may contain noise signals and interference signals. The filtering unit 40 can effectively filter out the noise (such as switching power supply noise, radio frequency interference) on the first bus CAN_H and the second bus CAN_L, thereby retaining the effective differential signal frequency band.

[0058] In some embodiments, as Figure 4 As shown, the filtering unit 40 includes: a first filter capacitor C1, a second filter capacitor C2 and a third filter capacitor C3; wherein, one end of the first filter capacitor C1 is connected to one end of the first terminal PIN1, and the other end of the first filter capacitor C1 is grounded; one end of the second filter capacitor C2 is grounded, and the other end of the second filter capacitor C2 is connected to one end of the second terminal PIN2; one end of the third filter capacitor C3 is connected to the connection point of the first terminal resistor R1 and the second terminal resistor R2, and the other end of the third filter capacitor C3 is grounded.

[0059] like Figure 1 As shown, the first filter capacitor C1 (connecting the first terminal PIN1 to ground) and the second filter capacitor C2 (connecting the second terminal PIN2 to ground) are common-mode filter capacitors that can effectively filter out common-mode noise and high-frequency interference in the bus signal to ensure the purity of the communication signal. The third filter capacitor C3 (connected between the midpoint of the first terminal resistor 20 and the second terminal resistor 20 and ground) further suppresses noise introduced by the resistor divider node, avoids signal reflections caused by impedance mutations, and improves signal integrity.

[0060] It should be noted that the resistor voltage dividing nodes are both connection points of the first terminal resistor R1 and the second terminal resistor R2.

[0061] In some embodiments, as Figure 5 As shown, the impedance matching circuit 100 further includes: a protection unit 50, which is arranged between one end of the first terminal PIN1 and one end of the second terminal PIN2, and is configured to provide overvoltage protection for the first bus CAN_H and the second bus CAN_L.

[0062] That is, when the voltage on the first bus CAN_H and the second bus CAN_L exceeds the preset voltage threshold, the protection unit 50 will respond quickly to clamp the voltage on the first bus CAN_H and the second bus CAN_L, thereby preventing the bus interface or the connected device from being damaged due to overvoltage and extending the service life of the device.

[0063] For example, in some embodiments, Figure 5 As shown, the protection unit 50 includes a first reverse diode Z1 and a second reverse diode Z2. One end of the first reverse diode Z1 is connected to one end of the first terminal PIN1. One end of the second reverse diode Z2 is connected to the other end of the first reverse diode Z2 and is grounded. The other end of the second reverse diode Z2 is connected to one end of the second terminal PIN2.

[0064] Specifically, during normal operation, the voltage difference between the first bus CAN_H and the second bus CAN_L is usually within a specified range, and the first reverse diode Z1 and the second reverse diode Z2 are both in a reverse biased state and will not conduct. Since the reverse impedance of the first reverse diode Z1 and the second reverse diode Z2 is very high, they will not have a significant impact on normal signal transmission. When the voltage of the first bus CAN_H is too high, the first reverse diode Z1 is forward biased, and current flows to ground through the first reverse diode Z1. The second reverse diode Z2 is reverse biased, acting as a clamp, limiting the excessive voltage to within the reverse breakdown voltage range of the second reverse diode Z2, thereby providing overvoltage protection for the circuit. When the voltage of the second bus CAN_L is too high, the second reverse diode Z2 is forward biased, and current flows to ground through the second reverse diode Z2. The first reverse diode Z1 is reverse biased, acting as a clamp, limiting the excessive voltage to within the reverse breakdown voltage range of the first reverse diode Z1, thereby providing overvoltage protection for the circuit.

[0065] In the above embodiment, the protection unit composed of two reverse diodes can effectively protect the two signal lines of the bus from overvoltage damage by ground clamping.

[0066] Further, such as Figure 6As shown, the impedance matching circuit 100 further includes: a first inductor L1 and a second inductor L2; wherein the first inductor L1 is arranged between the second end of the signal transmission unit 10 and one end of the first terminal PIN1; the second inductor L2 is arranged between the third end of the signal transmission unit 10 and one end of the second terminal PIN2.

[0067] In the present application, the first inductor L1 and the second inductor L2 present high impedance to high-frequency noise, and can filter out electromagnetic interference (EMI) or radio frequency noise (such as engine ignition noise in a car CAN bus) on the first bus CAN_H and the second bus CAN_L to protect the signal transmission unit 10 from damage.

[0068] The embodiment of the present application also provides a bus network system. Figure 7 As shown, the bus network system includes: at least one impedance matching circuit 100 and at least one controller 200; wherein, each impedance matching circuit 100 is suitable for connecting the first bus CAN-H and the second bus CAN-L, and is connected to a controller 20, and each impedance matching circuit 100 is configured to perform impedance matching on the corresponding controller according to the position information of the corresponding controller.

[0069] The bus network system of this embodiment matches the terminal resistance of the controller through an impedance matching circuit, so that the same controller can be adapted to different vehicle models or platforms. Therefore, the hardware circuits of all controllers can remain consistent, and there is no need to manage the part numbers of multiple controllers, thereby effectively reducing the number of variants of controller products and improving platform compatibility.

[0070] The present application also provides an impedance matching method for use in Figure 1 The impedance matching circuit shown in FIG. 1 includes: a signal transmission unit 10, a wiring terminal, a terminal resistor 20 and an impedance matching unit 30. The first end of the signal transmission unit 10 is suitable for connecting to the controller 200. The wiring terminal includes a first wiring terminal PIN1, a second wiring terminal PIN2, a third wiring terminal PIN3 and a fourth wiring terminal PIN4. One end of the first wiring terminal PIN1 is connected to the second end of the signal transmission unit 10, and the other end of the first wiring terminal PIN1 is suitable for connecting to the first bus CAN_H. One end of the second wiring terminal PIN2 is respectively connected to the third end of the signal transmission unit 10 and one end of the third wiring terminal PIN3, and the other end of the second wiring terminal PIN2 is suitable for connecting to the second bus CAN_L. One end of the terminal resistor 20 is respectively connected to one end of the first wiring terminal PIN1 and the second end of the signal transmission unit 10, and the other end of the terminal resistor 20 is connected to one end of the fourth wiring terminal PIN4.

[0071] Among them, such as Figure 8As shown, impedance matching methods include:

[0072] S301 : Control the connection state between the third wiring terminal and the fourth wiring terminal according to position information of the controller, so that a terminal resistor is connected between the first bus and the second bus.

[0073] In some embodiments, the connection state between the third terminal and the fourth terminal is controlled according to the position information of the controller so that the terminal resistor is connected between the first bus and the second bus, including: when it is determined according to the position information that the controller needs to be configured with a terminal resistor, the third terminal and the fourth terminal are connected so that the terminal resistor is connected between the first bus and the second bus; or, when it is determined according to the position information that the controller does not need to be configured with a terminal resistor, the third terminal and the fourth terminal are disconnected.

[0074] It should be noted that the specific implementation of the impedance matching method in the embodiment of the present invention corresponds one-to-one to the specific implementation of the impedance matching circuit in the aforementioned embodiment of the present invention, and will not be described in detail here.

[0075] The impedance matching method provided in this application enables the same controller to adapt to different vehicle models or platforms by matching the terminal resistance of the controller. Therefore, the hardware circuits of all controllers can be kept consistent, and there is no need to manage the part numbers of multiple controllers, thereby effectively reducing the number of variants of controller products and improving platform compatibility.

[0076] It should be noted that the logic and / or steps represented in the flowcharts or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing the logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other system that can fetch and execute instructions from an instruction execution system, apparatus, or device), or in conjunction with such instruction execution system, apparatus, or device. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transmit a program for use by an instruction execution system, apparatus, or device, or in conjunction with such instruction execution system, apparatus, or device. More specific examples (non-exhaustive list) of computer-readable media include the following: an electrical connection portion having one or more wires (electronic device), a portable computer disk cartridge (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and programmable read-only memory (EPROM or flash memory), fiber optic devices, and portable compact disc read-only memory (CDROM). Furthermore, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing it in another suitable manner if necessary, and then storing it in a computer memory.

[0077] It should be understood that various parts of the present invention can be implemented using hardware, software, firmware, or a combination thereof. In the above-described embodiments, multiple steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0078] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0079] In addition, the terms "first" and "second" used in the embodiments of the present invention are only used for descriptive purposes and should not be understood as indicating or implying relative importance, or implicitly indicating the number of technical features indicated in this embodiment. Therefore, the features defined by the terms "first" and "second" in the embodiments of the present invention can explicitly or implicitly indicate that the embodiment includes at least one of such features. In the description of the present invention, the word "plurality" means at least two or two or more, such as two, three, four, etc., unless otherwise clearly and specifically defined in the embodiments.

[0080] In the present invention, unless otherwise clearly specified or limited in the embodiments, the terms "installed," "connected," "connect," and "fixed" appearing in the embodiments should be understood in a broad sense. For example, the connection may be a fixed connection, a detachable connection, or an integral connection. It can also be a mechanical connection, an electrical connection, etc.; of course, it can also be a direct connection, or an indirect connection through an intermediate medium, or it can be internal communication between two elements, or an interaction between two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood based on the specific implementation.

[0081] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. An impedance matching circuit, characterized in that: include: Signal transmission unit, wiring terminal, terminal resistor and impedance matching unit; wherein, The first end of the signal transmission unit is suitable for connecting to a controller; The wiring terminal includes a first wiring terminal, a second wiring terminal, a third wiring terminal and a fourth wiring terminal, one end of the first wiring terminal is connected to the second end of the signal transmission unit, and the other end of the first wiring terminal is suitable for connecting to a first bus, one end of the second wiring terminal is respectively connected to the third end of the signal transmission unit and one end of the third wiring terminal, and the other end of the second wiring terminal is suitable for connecting to a second bus; One end of the terminal resistor is connected to one end of the first wiring terminal and the second end of the signal transmission unit respectively, and the other end of the terminal resistor is connected to one end of the fourth wiring terminal; The impedance matching unit is configured to control a connection state between the third terminal and the fourth terminal according to position information of the controller, so that the terminal resistor is connected between the first bus and the second bus.

2. The impedance matching circuit according to claim 1, wherein: The impedance matching unit is further configured to: When it is determined according to the position information that the controller needs to be configured with a terminal resistor, connecting the third wiring terminal and the fourth wiring terminal so that the terminal resistor is connected between the first bus and the second bus; or When it is determined according to the position information that the controller does not need to be configured with a terminal resistor, the third wiring terminal and the fourth wiring terminal are disconnected.

3. The impedance matching circuit according to claim 2, wherein: The impedance matching unit includes: a controllable switch and a control module; wherein, One end of the controllable switch is connected to the other end of the third terminal, and the other end of the controllable switch is connected to the other end of the fourth terminal; The control module is connected to the controllable switch, and is configured to perform on-off control on the controllable switch according to the position information, so that the controllable switch controls the connection state between the third terminal and the fourth terminal.

4. The impedance matching circuit according to any one of claims 1 to 3, characterized in that: The terminal resistor includes a first terminal resistor and a second terminal resistor, wherein the first terminal resistor and the second terminal resistor are connected in series and are arranged between one end of the first terminal and the other end of the fourth terminal.

5. The impedance matching circuit according to claim 4, wherein: Also includes: A filtering unit is connected to one end of the first wiring terminal and one end of the second wiring terminal respectively, and is configured to filter the electrical signals on the first bus and the second bus.

6. The impedance matching circuit according to claim 5, wherein: The filtering unit includes: a first filtering capacitor, a second filtering capacitor and a third filtering capacitor; wherein, One end of the first filter capacitor is connected to one end of the first wiring terminal, and the other end of the first filter capacitor is grounded; One end of the second filter capacitor is grounded, and the other end of the second filter capacitor is connected to one end of the second wiring terminal; One end of the third filter capacitor is connected to a connection point between the first terminal resistor and the second terminal resistor, and the other end of the third filter capacitor is grounded.

7. The impedance matching circuit according to claim 1, wherein: Also includes: A protection unit is provided between one end of the first wiring terminal and one end of the second wiring terminal, and is configured to provide overvoltage protection for the first bus and the second bus.

8. The impedance matching circuit according to claim 7, wherein: The protection unit includes: a first reverse diode and a second reverse diode; wherein, One end of the first reverse diode is connected to one end of the first wiring terminal; One end of the second reverse diode is connected to the other end of the first reverse diode and is grounded, and the other end of the second reverse diode is connected to one end of the second wiring terminal.

9. A bus network system, characterized in that: include: at least one impedance matching circuit and at least one controller; wherein, Each impedance matching circuit is adapted to connect the first bus and the second bus and is connected to a controller. Each impedance matching circuit is configured to perform impedance matching on the corresponding controller according to position information of the corresponding controller.

10. An impedance matching method, characterized in that: Applied to an impedance matching circuit, the impedance matching circuit includes: a signal transmission unit, a wiring terminal, a terminal resistor and an impedance matching unit, the first end of the signal transmission unit is suitable for connecting to a controller, the wiring terminal includes a first wiring terminal, a second wiring terminal, a third wiring terminal and a fourth wiring terminal, one end of the first wiring terminal is connected to the second end of the signal transmission unit, the other end of the first wiring terminal is suitable for connecting to a first bus, one end of the second wiring terminal is respectively connected to the third end of the signal transmission unit and one end of the third wiring terminal, the other end of the second wiring terminal is suitable for connecting to a second bus, one end of the terminal resistor is respectively connected to one end of the first wiring terminal and the second end of the signal transmission unit, and the other end of the terminal resistor is connected to one end of the fourth wiring terminal. The method includes: The connection state between the third wiring terminal and the fourth wiring terminal is controlled according to the position information of the controller, so that the terminal resistor is connected between the first bus and the second bus.

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