Signal carrier power line transmission isolation system of vehicle-mounted CAN local area network
By using external and internal wave blockers and shielding layers in the on-board CAN LAN, the electromagnetic anti-interference problem of CAN node modules to external systems and internal functional modules is solved, electromagnetic isolation is achieved and energy loss is reduced.
Patent Information
- Application Number
- CN202422019658.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-20
- Publication Date
- 2025-07-08
- Estimated Expiration
- 2034-08-20
AI Technical Summary
The CAN node module in the on-board CAN LAN affects the electromagnetic anti-interference performance of external systems and other internal functional modules during the transmission of carrier power lines.
External and internal wave blockers are used to filter out high-frequency carrier signals respectively, and external interference is shielded through the shielding layer. Combined with a patch overcurrent protector, the electromagnetic isolation between the CAN node module and the external system and other internal functional modules is achieved.
The impact of the CAN node module on the electromagnetic anti-interference performance of the external system and other internal functional modules is reduced or avoided, while reducing the energy loss of high-frequency carrier signals.
Smart Images
Figure CN223080030U_ABST
Abstract
Description
Technical Field
[0001] This specification relates to the technical field of in-vehicle Controller Area Network (CAN) local area network, and particularly to a signal carrier power line transmission isolation system for an in-vehicle CAN local area network. Background Art
[0002] In-vehicle Controller Area Network (CAN) is a high-speed serial communication protocol bus widely used inside automobiles and is one of the indispensable standard communication methods in the current automotive industry. The in-vehicle CAN local area network generally adopts a communication mechanism of multi-master and slave structure, allowing multiple components in the vehicle, such as engine control units, braking systems, and body electronic control units, to interact information through the CAN controller of the in-vehicle CAN local area network.
[0003] However, in the process of implementing this application, the inventors of this application found that: the CAN node module for carrier power line transmission in the in-vehicle CAN local area network will affect the Electro Magnetic Susceptibility (EMS) performance of external systems (device components in the vehicle that interact with the in-vehicle CAN local area network) and other internal functional modules (functional modules in the CAN node module that are not used to implement carrier power line transmission). Summary of the Utility Model
[0004] The purpose of the embodiments of this specification is to provide a signal carrier power line transmission isolation system for an in-vehicle CAN local area network to reduce or avoid the CAN node module for carrier power line transmission in the in-vehicle CAN local area network from affecting the EMS performance of external systems and other internal functional modules.
[0005] To achieve the above object, on the one hand, the embodiments of this specification provide a signal carrier power line transmission isolation system for an in-vehicle CAN local area network. The in-vehicle CAN local area network includes one or more CAN node modules for carrier power line transmission, and each CAN node module is connected to an in-vehicle DC power supply through a wire. The system includes:
[0006] An external choke coil disposed at the power output end of the in-vehicle DC power supply for filtering high-frequency carrier signals on the power output end side;
[0007] An internal choke coil disposed at the power supply output end inside each CAN node module for filtering high-frequency carrier signals on the power supply output end side of the corresponding CAN node module.
[0008] In the signal carrier power line transmission isolation system of the in-vehicle CAN local area network according to the embodiments of the present specification, the external choke includes a first choke and a second choke; the first choke is connected in series to the positive pole of the in-vehicle DC power supply and is used to filter out the high-frequency carrier signals on the positive pole side; the second choke is connected in series to the negative pole of the in-vehicle DC power supply and is used to filter out the high-frequency carrier signals on the negative pole side.
[0009] In the signal carrier power line transmission isolation system of the in-vehicle CAN local area network according to the embodiments of the present specification, each of the internal chokes includes a third choke and a fourth choke; each of the third chokes is connected in series to the positive pole of the power supply output in the corresponding CAN node module and is used to filter out the high-frequency carrier signals on the positive pole side of the power supply output in the corresponding CAN node module; each of the fourth chokes is connected in series to the negative pole of the power supply output in the corresponding CAN node module and is used to filter out the high-frequency carrier signals on the negative pole side of the power supply output in the corresponding CAN node module.
[0010] In the signal carrier power line transmission isolation system of the in-vehicle CAN local area network according to the embodiments of the present specification, the system further includes:
[0011] A patch type overcurrent protector connected in series with the first choke.
[0012] In the signal carrier power line transmission isolation system of the in-vehicle CAN local area network according to the embodiments of the present specification, the patch type overcurrent protector is a patch fuse.
[0013] In the signal carrier power line transmission isolation system of the in-vehicle CAN local area network according to the embodiments of the present specification, the first choke and the second choke are any one of the following:
[0014] A single choke;
[0015] A parallel combination of multiple chokes;
[0016] A parallel combination of a choke and a filter capacitor.
[0017] In the signal carrier power line transmission isolation system of the in-vehicle CAN local area network according to the embodiments of the present specification, the third choke and the fourth choke are any one of the following:
[0018] A single choke;
[0019] A parallel combination of multiple chokes;
[0020] A parallel combination of a choke and a filter capacitor.
[0021] In the signal carrier power line transmission isolation system of the in-vehicle CAN local area network according to the embodiments of the present specification, the system further includes:
[0022] A shielding layer, which is coated on the outer surface of the wire and is used to shield external high-frequency electromagnetic interference.
[0023] In the signal carrier power line transmission isolation system of the in-vehicle CAN local area network according to the embodiment of the present specification, the grounding end of the shielding layer is located outside the CAN node module.
[0024] In the signal carrier power line transmission isolation system of the in-vehicle CAN local area network according to the embodiment of the present specification, the grounding end of the shielding layer is connected to the negative pole of the in-vehicle DC power supply.
[0025] As can be seen from the technical solutions provided by the embodiments of the present specification above, in the embodiments of the present specification, the external choke can be used to isolate the high-frequency carrier signal in the CAN node module for carrier power line transmission from the external system (device components in the vehicle that interact with the in-vehicle CAN local area network), so as to reduce or avoid the CAN node module for carrier power line transmission in the in-vehicle CAN local area network from affecting the EMS performance of the external system; the internal choke can be used to isolate the high-frequency carrier signal in the CAN node module for carrier power line transmission from other internal functional modules (functional modules in the CAN node module that are not used to implement carrier power line transmission), so as to reduce or avoid the CAN node module for carrier power line transmission in the in-vehicle CAN local area network from affecting the EMS performance of other internal functional modules. Moreover, since the embodiments of the present specification can reduce or avoid the CAN node module for carrier power line transmission in the in-vehicle CAN local area network from affecting the EMS performance of the external system and other internal functional modules, the energy loss of the high-frequency carrier signal of the CAN node module for carrier power line transmission in the in-vehicle CAN local area network is also reduced. Description of the Drawings
[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present specification or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in the present specification. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings. In the drawings:
[0027] Figure 1 It is a structural block diagram of the signal carrier power line transmission isolation system of the in-vehicle CAN local area network in some embodiments of the present specification;
[0028] Figure 2 It is a schematic diagram of the principle of the signal carrier power line transmission isolation system of the in-vehicle CAN local area network in some embodiments of the present specification;
[0029] Figure 3Schematic diagram of the principle of the signal carrier power line transmission isolation system for in-vehicle CAN local area network in some other embodiments of this specification;
[0030] Figure 4 Schematic diagram of the principle of the signal carrier power line transmission isolation system for in-vehicle CAN local area network in some other embodiments of this specification;
[0031] Figure 5 Schematic diagram of the structure of an external choke in an exemplary embodiment of this specification;
[0032] Figure 6 Schematic diagram of the structure of an external choke in another exemplary embodiment of this specification;
[0033] Figure 7 Schematic diagram of the structure of an internal choke in an exemplary embodiment of this specification;
[0034] Figure 8 Schematic diagram of the structure of an internal choke in another exemplary embodiment of this specification.
[0035]
Description of the reference numerals
[0036] 1. Vehicle-mounted DC power supply;
[0037] 2. CAN node module;
[0038] 3. Conducting wire;
[0039] 4. External choke;
[0040] 5. Internal choke;
[0041] 6. Chip-type overcurrent protector;
[0042] 7. Shielding layer. Detailed implementation manners
[0043] In order to enable those skilled in the art to better understand the technical solutions in this specification, the following will clearly and completely describe the technical solutions in the embodiments of this specification with reference to the accompanying drawings in the embodiments of this specification. Obviously, the described embodiments are only some embodiments of this specification, rather than all the embodiments. Based on the embodiments in this specification, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this specification. For example, in the following description, forming the second component above the first component may include embodiments in which the first component and the second component are formed in direct contact, and may also include embodiments in which the first component and the second component are formed in a non-direct contact manner (that is, additional components may be included between the first component and the second component), etc.
[0044] Moreover, for ease of description, some embodiments of this specification may use spatial relative terms such as "above", "below", "top", "bottom", etc. to describe the relationship between one element or component and another (or other) element or component as shown in the respective drawings of the embodiments. It should be understood that, in addition to the orientations described in the drawings, spatial relative terms are also intended to include different orientations during the use or operation of the device. For example, if the device in the drawing is flipped, an element or component described as "below" or "beneath" other elements or components will subsequently be positioned "above" or "on top of" other elements or components.
[0045] Referring Figure 1 As shown, in the signal carrier power line transmission isolation system of the in-vehicle CAN local area network in some embodiments of this specification, the in-vehicle CAN local area network includes one or more CAN node modules 2 for carrier power line transmission, and each of the CAN node modules 2 is connected to the in-vehicle DC power supply 1 through a wire 3. The system further includes an external choke 4 and an internal choke 5. The external choke 4 is connected in series to the power output terminal of the in-vehicle DC power supply 1 for filtering high-frequency carrier signals on the power output terminal side; the internal choke 5 is connected in series to the power supply output terminal within the corresponding CAN node module 2 for filtering high-frequency carrier signals on the power supply output terminal side within the corresponding CAN node module 2.
[0046] In the embodiments of this specification, since the choke connected in series to the power output terminal of the in-vehicle DC power supply 1 is located outside the in-vehicle CAN local area network, the choke connected in series to the power output terminal of the in-vehicle DC power supply 1 can be referred to as the external choke 4. Since the choke connected in series to the power supply output terminal within each CAN node module 2 is located within the in-vehicle CAN local area network, the choke connected in series to the power supply output terminal within each CAN node module 2 can be referred to as the internal choke 5.
[0047] In the embodiments of this specification, the external choke 4 can isolate the high-frequency carrier signal in the CAN node module 2 for carrier power line transmission from the external system (the device components in the vehicle that interact with the in-vehicle CAN local area network), thereby reducing or avoiding the CAN node module 2 for carrier power line transmission in the in-vehicle CAN local area network from affecting the EMS performance of the external system; the internal choke 5 can isolate the high-frequency carrier signal in the CAN node module 2 for carrier power line transmission from other internal functional modules (the functional modules in the CAN node module 2 that are not used to implement carrier power line transmission), thereby reducing or avoiding the CAN node module 2 for carrier power line transmission in the in-vehicle CAN local area network from affecting the EMS performance of other internal functional modules. Moreover, since the embodiments of this specification can reduce or avoid the CAN node module 2 for carrier power line transmission in the in-vehicle CAN local area network from affecting the EMS performance of the external system and other internal functional modules, it also reduces the energy loss of the high-frequency carrier signal of the CAN node module 2 for carrier power line transmission in the in-vehicle CAN local area network.
[0048] It should be noted that in the embodiments of this specification, the filtered high-frequency carrier signals are all high-frequency carrier signals that cause interference (i.e., are not desired) to the in-vehicle CAN local area network or the external system.
[0049] Combined with Figure 2 As shown, in some embodiments of this specification, the external choke may include a first choke and a second choke; the first choke is connected in series to the positive pole of the vehicle-mounted DC power supply (such as Figure 2 the 12V+ of the vehicle battery in Figure 2 ), and is used to filter the high-frequency carrier signal on the positive pole side (including the high-frequency carrier signal introduced by the vehicle-mounted DC power supply due to environmental interference and other reasons, as well as the high-frequency carrier signal partially leaked from the in-vehicle CAN local area network to the outside); the second choke is connected in series to the negative pole of the vehicle-mounted DC power supply (such as the 12V- of the vehicle battery in ), and is used to filter the high-frequency carrier signal on the negative pole side (including the high-frequency carrier signal introduced by the vehicle-mounted DC power supply due to environmental interference and other reasons, as well as the high-frequency carrier signal partially leaked from the in-vehicle CAN local area network to the outside).
[0050] Please continue to refer to Figure 2 As shown, in some embodiments of this specification, each internal choke may include a third choke and a fourth choke; each third choke is connected in series to the positive pole of the power supply output in the corresponding CAN node module (such as Figure 2the 12V+ terminal within the CAN node module), which is used to filter out high-frequency carrier signals on the positive electrode side of the power supply output within the corresponding CAN node module (including high-frequency carrier signals leaked from the CAN node module to other internal functional modules); each of the fourth choke coils is connected in series to the negative electrode of the power supply output within the corresponding CAN node module (such as Figure 2 the 12V- terminal within the CAN node module), which is used to filter out high-frequency carrier signals on the negative electrode side of the power supply output within the corresponding CAN node module (including high-frequency carrier signals leaked from the CAN node module to other internal functional modules).
[0051] In some embodiments of this specification, the parameter values of the choke coils can be designed according to relevant parameters such as the carrier frequency (i.e., the carrier frequency within the corresponding CAN node module). For example, the choke coil can be an inductive element designed according to the frequency of the CAN message modulation wave, and can meet the load requirements of the in-vehicle CAN local area network (for example, the power-on heating needs to meet the vehicle temperature rise requirements) to filter out the CAN message modulation high-frequency wave to the greatest extent.
[0052] In some embodiments of this specification, on the premise of meeting the preset requirements, the first choke coil, the second choke coil, the third choke coil, and the fourth choke coil can all be single choke coils to simplify the system structure and save system costs.
[0053] In some embodiments of this specification, when it is difficult to meet the preset requirements with a single choke coil, the first choke coil, the second choke coil, the third choke coil, and the fourth choke coil can be a parallel combination of multiple choke coils to make the choke coil meet the preset requirements.
[0054] For example, in Figure 5 the shown exemplary embodiment, taking the first choke coil (the choke coil connected to the vehicle battery 12V+) and the second choke coil (the choke coil connected to the vehicle battery 12V-) as external choke coils as an example, the first choke coil can be a parallel combination of three choke coils (see the dashed box in Figure 5 ), and the second choke coil can also be a parallel combination of three choke coils (see the dashed box in Figure 5 ).
[0055] For example, in Figure 7 the shown exemplary embodiment, taking the third choke coil (the choke coil connected to the 12V+ terminal within the CAN node module) and the fourth choke coil (the choke coil connected to the 12V- terminal within the CAN node module) as internal choke coils as an example, the third choke coil can be a parallel combination of two choke coils (see the dashed box in Figure 7 ), and the fourth choke coil can also be a parallel combination of two choke coils (see the dashed box in Figure 7 ).
[0056] In some other embodiments of this specification, when it is difficult to meet the preset requirements with a single choke, the first choke, the second choke, the third choke, and the fourth choke can be a parallel combination of a choke and a filter capacitor to enable the choke to meet the preset requirements.
[0057] For example, in the exemplary embodiment as shown in Figure 6 taking the first choke (the choke connected to the 12V+ of the vehicle-mounted battery) and the second choke (the choke connected to the 12V- of the vehicle-mounted battery) which are used as external chokes as an example, the first choke can be a parallel combination of a choke and a filter capacitor (see the dashed box in Figure 6 ), and the second choke can also be a parallel combination of a choke and a filter capacitor (see the dashed box in Figure 6 ).
[0058] For example, in the exemplary embodiment as shown in Figure 8 taking the third choke (the choke connected to the 12V+ terminal in the CAN node module) and the fourth choke (the choke connected to the 12V- terminal in the CAN node module) which are used as internal chokes as an example, the third choke can be a parallel combination of a choke and a filter capacitor (see the dashed box in Figure 8 ), and the fourth choke can also be a parallel combination of a choke and a filter capacitor (see the dashed box in Figure 8 ).
[0059] Referring to Figure 3 as shown, in some embodiments of this specification, the signal carrier power line transmission isolation system of the vehicle-mounted CAN local area network may further include a surface-mounted overcurrent protector 6 (such as a surface-mounted fuse, etc.) connected in series with the first choke. In this way, short-circuit overload protection for the wire and its downstream (i.e., the vehicle-mounted CAN local area network) can also be achieved. Moreover, since the vehicle-mounted DC power supply and the CAN node module are generally arranged on the printed circuit board, using the surface-mounted overcurrent protector 6 is also convenient for assembly and saves space. In actual implementation, a suitable surface-mounted overcurrent protector 6 can be selected according to the load nature of different power cables and the cable square number. In addition, since the negative wire of the vehicle-mounted DC power supply is the loop from the positive pole through the load to the ground wire, and it is itself short-circuited to the ground wire and there is no short-circuit phenomenon, short-circuit overload protection is not required.
[0060] Referring to Figure 4As shown, in some embodiments of this specification, the signal carrier power line transmission isolation system of the in-vehicle CAN local area network may further include a shielding layer 7 wrapped around the outer surface of the wire. The shielding layer 7 can be used to shield external high-frequency electromagnetic interference. Among them, the grounding end of the shielding layer 7 can be located outside the CAN node module. For example, the grounding end of the shielding layer 7 can be connected to the negative pole of the in-vehicle DC power supply. In this way, the influence of the electromagnetic antenna effect of the shielding layer 7 on the vehicle's EMS can be reduced or avoided.
[0061] In addition, in Figure 2 , Figure 7 and Figure 8 , the positive wire in the wire can be connected to the frequency selection module and modulation module in the CAN node module through a coupler for transmitting the CAN_H modulation signal (i.e., the part of the modulation signal with a higher voltage in the dominant state), and the negative wire in the wire can also be connected to the frequency selection module and modulation module in the CAN node module through a coupler for transmitting the CAN_L modulation signal (i.e., the part of the modulation signal with a lower voltage in the dominant state).
[0062] For the convenience of description, the above device is described by dividing it into various units according to functions. Of course, when implementing this specification, the functions of each unit can be realized in the same or multiple hardware structures.
[0063] It should also be understood that in the embodiments of this specification, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this article generally represents an "or" relationship between the associated objects before and after.
[0064] It should also be noted that the term "comprises", "comprising" or any other variation thereof is intended to cover a non-exclusive inclusion, such that a device or equipment comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements that are inherent to such device or equipment. Without further limitation, an element defined by the statement "comprising a..." does not exclude the existence of additional identical elements in the device or equipment comprising the element.
[0065] The above are only the embodiments of this application and are not used to limit this application. For those skilled in the art, this application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this application shall be included within the scope of the claims of this application.
Claims
1. A signal carrier power line transmission isolation system for a vehicle-mounted CAN local area network, characterized in that The in-vehicle CAN local area network includes one or more CAN node modules for carrier power line transmission, and each of the CAN node modules is connected to an in-vehicle DC power supply through a wire. The system includes: An external choke coil disposed at the power output terminal of the in-vehicle DC power supply for filtering high-frequency carrier signals on the power output terminal side; An internal choke coil disposed at the power supply output terminal within each CAN node module for filtering high-frequency carrier signals on the power supply output terminal side within the corresponding CAN node module.
2. The signal carrier power line transmission isolation system for an in-vehicle CAN local area network according to claim 1, wherein, The external choke coil includes a first choke coil and a second choke coil; the first choke coil is connected in series to the positive pole of the in-vehicle DC power supply for filtering high-frequency carrier signals on the positive pole side; the second choke coil is connected in series to the negative pole of the in-vehicle DC power supply for filtering high-frequency carrier signals on the negative pole side.
3. The signal carrier power line transmission isolation system for an in-vehicle CAN local area network according to claim 1, characterized in that, Each internal choke coil includes a third choke coil and a fourth choke coil; each third choke coil is connected in series to the positive pole of the power supply output terminal within the corresponding CAN node module for filtering high-frequency carrier signals on the positive pole side of the power supply output terminal within the corresponding CAN node module; each fourth choke coil is connected in series to the negative pole of the power supply output terminal within the corresponding CAN node module for filtering high-frequency carrier signals on the negative pole side of the power supply output terminal within the corresponding CAN node module.
4. The signal carrier power line transmission isolation system for in-vehicle CAN local area network according to claim 2, wherein The system further includes: A patch type overcurrent protector connected in series with the first choke coil.
5. The signal carrier power line transmission isolation system for an in-vehicle CAN local area network according to claim 4, wherein The patch type overcurrent protector is a patch fuse.
6. The signal carrier power line transmission isolation system of the in-vehicle CAN local area network according to claim 2, characterized in that, The first choke coil and the second choke coil are any one of the following: A single choke coil; A parallel combination of multiple choke coils; A parallel combination of a choke coil and a filter capacitor.
7. The signal carrier power line transmission isolation system of the in-vehicle CAN local area network according to claim 3, characterized in that, The third choke coil and the fourth choke coil are any one of the following: A single choke coil; A parallel combination of multiple choke coils; A parallel combination of a choke coil and a filter capacitor.
8. The signal carrier power line transmission isolation system for vehicle-mounted CAN local area network according to claim 1, characterized in that The system further includes: A shielding layer covering the outer surface of the wire for shielding external high-frequency electromagnetic interference.
9. The signal carrier power line transmission isolation system of the in-vehicle CAN local area network according to claim 8, wherein, The grounding end of the shielding layer is located outside the CAN node module.
10. The signal carrier power line transmission isolation system for an in-vehicle CAN local area network according to claim 8, characterized in that The grounding end of the shielding layer is connected to the negative pole of the in-vehicle DC power supply.