Methods for determining filter devices, storage media, and filter devices

Abstract

This application provides a method for determining a filtering device, a storage medium, and a filtering device. The method includes acquiring a first test result, which is obtained by conducting conducted EMI interference testing on a first domain controller based on a current method. Based on the first test result, a first out-of-range frequency point of the first domain controller is determined. The rated current of a common-mode inductor is determined based on the actual input current of the first domain controller. A first AC resistance of the common-mode inductor is determined based on the out-of-range value corresponding to the first out-of-range frequency point and the first out-of-range frequency point. A target size of the common-mode inductor is determined based on the spatial dimensions of the first domain controller. The common-mode inductor is then designated as the first filtering device for the first domain controller, thereby performing conducted EMI filtering on the first domain controller. This embodiment enables rapid, effective, and low-cost conducted EMI interference testing through a domain controller.

Description

Technical Field

[0001] This application relates to the field of automotive electronics technology, and in particular to a method for determining a filter device, a storage medium, and a filter device. Background Technology

[0002] With the increasing adoption of automotive electronic intelligent driving domain controllers, the functions they support are becoming more powerful, and their power consumption is also gradually increasing. Switching power supplies, due to their high efficiency and widespread availability, are widely used in automotive electronic intelligent driving domain controllers. As the frequency of switching power supplies gradually increases and the number of switching power supplies also increases, switching noise has become a major source of conducted electromagnetic interference (EMI). Current-method testing is a crucial test in the conducted EMI interference testing of automotive electronic intelligent driving domain controllers. How to solve the problem of conducted EMI interference frequency exceeding the standard in current-method testing is currently an important issue.

[0003] In related technologies, different methods such as grounding, shielding, and filtering, or a combination of these methods, can be used to solve the problem of domain controllers failing conducted EMI interference tests.

[0004] However, in the process of developing this application, the inventors discovered at least the following problems with the existing technology: grounding methods that require modifications to the housing structure or adjustments to the printed circuit board layout involve excessive changes, long completion cycles, and low efficiency; using pre-made filters results in excessively large sizes; and because domain controllers have fixed sizes, numerous functions and components, high component and wiring density, and limited remaining space within the housing, it becomes impossible to place the aforementioned filtering devices inside the domain controller, and the cost is also high. How to quickly, effectively, and cost-efficiently conduct EMI interference testing through domain controllers is an urgent problem to be solved. Summary of the Invention

[0005] This application provides a method for determining a filtering device, a storage medium, and a filtering device, so as to quickly, effectively, and cost-efficiently conduct EMI interference tests through a domain controller.

[0006] In a first aspect, embodiments of this application provide a method for determining a filtering device, including:

[0007] Obtain the first test result; the first test result is obtained by conducting conducted EMI interference tests on the first domain controller based on the current method.

[0008] Based on the first test results, determine the first out-of-range frequency point range of the first domain controller;

[0009] The rated current of the common-mode inductor is determined based on the actual input current of the first domain controller;

[0010] The first AC resistance of the common-mode inductor is determined based on the excess value corresponding to the first excess frequency range and the first excess frequency range.

[0011] The target size of the common-mode inductor is determined based on the spatial dimensions of the first domain controller;

[0012] The common-mode inductor is designated as the first filter device for the first domain controller, so as to perform conducted EMI filtering on the first domain controller through the first filter device.

[0013] In one possible design, the method further includes:

[0014] Obtain the second test result; the second test result is obtained by conducting EMI interference test on the second domain controller based on the current method; the second domain controller is obtained by connecting the first filter device to the input terminal of the switching power supply of the first domain controller;

[0015] Based on the second test results, determine the range of the second out-of-range frequency points for the second domain controller;

[0016] Based on the second out-of-range frequency point, the first filter device is adjusted to obtain a second filter device for the first domain controller, so as to perform conducted EMI filtering on the first domain controller through the second filter device.

[0017] In one possible design, adjusting the first filtering device according to the second out-of-range frequency point to obtain a second filtering device for the first domain controller includes:

[0018] The second AC resistance of the common-mode inductor is determined based on the excess value within the second excess frequency range;

[0019] Based on the second AC resistance, select a new common-mode inductor;

[0020] If the size of the new common-mode inductor is smaller than the space size, then the new common-mode inductor is determined as the second filtering device of the first domain controller.

[0021] In one possible design, determining the second AC resistance of the common-mode inductor based on the out-of-range value within the second out-of-range frequency range includes:

[0022] If the rated current of the common-mode inductor is less than a preset threshold, then the second AC resistance of the common-mode inductor is determined based on the excess value within the second excess frequency range.

[0023] In one possible design, adjusting the first filtering device according to the second out-of-range frequency point to obtain a second filtering device for the first domain controller includes:

[0024] The rated current of the inductor bead is determined based on the rated current of the common mode inductor.

[0025] The third AC resistance of the inductive bead is determined based on the excess value within the second excess frequency range and the second excess frequency range.

[0026] The inductor bead is connected in series with the rear end of the common-mode inductor to obtain the second filtering device of the first domain controller.

[0027] In one possible design, the method further includes:

[0028] Obtain a third test result; the third test result is obtained by conducting EMI interference tests on the third domain controller based on the current method; the third domain controller is obtained by connecting the second filter device to the input terminal of the switching power supply of the first domain controller;

[0029] Based on the third test results, determine whether the third domain controller has any frequency points exceeding the standard.

[0030] If there are no out-of-range frequency points in the third domain controller, then the second filtering device will be determined as the final filtering device.

[0031] In one possible design, the method further includes:

[0032] If the third domain controller has an out-of-range frequency, the second filter device is adjusted according to the out-of-range value of the out-of-range frequency of the third domain controller and the out-of-range frequency of the third domain controller to obtain a third filter device, so as to perform conducted EMI filtering on the first domain controller through the third filter device.

[0033] Secondly, embodiments of this application provide a device for determining a filtering apparatus, comprising:

[0034] The acquisition module is used to acquire the first test result; the first test result is obtained by conducting conducted EMI interference tests on the first domain controller based on the current method.

[0035] The processing module is used to determine the first out-of-range frequency point range of the first domain controller based on the first test result;

[0036] The rated current of the common-mode inductor is determined based on the actual input current of the first domain controller;

[0037] The first AC resistance of the common-mode inductor is determined based on the excess value corresponding to the first excess frequency range and the first excess frequency range.

[0038] The target size of the common-mode inductor is determined based on the spatial dimensions of the first domain controller;

[0039] The common-mode inductor is designated as the first filter device for the first domain controller, so as to perform conducted EMI filtering on the first domain controller through the first filter device.

[0040] Thirdly, embodiments of this application provide a filtering device, including:

[0041] A common-mode inductor is connected to the input terminal of the switching power supply of the first domain controller and is used to perform conducted EMI filtering on the first domain controller.

[0042] The target size of the common-mode inductor is determined based on the spatial dimensions of the first domain controller; the rated current of the common-mode inductor is determined based on the actual input current of the first domain controller; the first AC resistance of the common-mode inductor is determined based on the out-of-range value corresponding to the first out-of-range frequency range and the first out-of-range frequency range; the first out-of-range frequency range of the first domain controller is determined based on the first test results; the first test results are obtained by conducting EMI interference tests on the first domain controller using the current method.

[0043] Fourthly, embodiments of this application provide a device for determining a filtering apparatus, comprising: at least one processor and a memory;

[0044] The memory stores computer-executed instructions;

[0045] The at least one processor executes computer execution instructions stored in the memory, causing the at least one processor to perform the method described in the first aspect above and various possible designs of the first aspect.

[0046] Fifthly, embodiments of this application provide a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the methods described in the first aspect and various possible designs of the first aspect.

[0047] Sixthly, embodiments of this application provide a computer program product, including a computer program that, when executed by a processor, implements the method described in the first aspect above and various possible designs of the first aspect.

[0048] This embodiment provides a method for determining a filtering device, a storage medium, and a filtering device. The method includes acquiring a first test result, obtained by performing conducted EMI interference testing on a first domain controller using the current method. Based on the first test result, a first out-of-range frequency point of the first domain controller is determined. The rated current of a common-mode inductor is determined based on the actual input current of the first domain controller. A first AC resistance of the common-mode inductor is determined based on the out-of-range value corresponding to the first out-of-range frequency point and the first out-of-range frequency point. A target size of the common-mode inductor is determined based on the spatial dimensions of the first domain controller. The common-mode inductor is then selected as the first filtering device for the first domain controller, enabling conducted EMI filtering of the first domain controller through the first filtering device. This method for determining a filtering device, by selecting a common-mode inductor as a filtering device based on the conducted EMI interference test results using the AC method, and further determining the parameter values ​​of the common-mode inductor based on the test results, enables rapid, effective, and low-cost conducted EMI interference testing through a domain controller. Attached Figure Description

[0049] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0050] Figure 1 A flowchart illustrating the method for determining the filtering device provided in the embodiments of this application. Figure 1 ;

[0051] Figure 2 This is a schematic diagram of the structure of the second domain controller provided in an embodiment of this application;

[0052] Figure 3 A schematic diagram of the first test result provided in an embodiment of this application;

[0053] Figure 4 A flowchart illustrating the method for determining the filtering device provided in the embodiments of this application. Figure 2 ;

[0054] Figure 5 This is a schematic diagram of the structure of the third domain controller provided in an embodiment of this application;

[0055] Figure 6 A schematic diagram of the second test results provided in an embodiment of this application;

[0056] Figure 7 A schematic diagram illustrating the third test results provided in an embodiment of this application;

[0057] Figure 8 This is a schematic diagram of the structure of the device used to determine the filtering apparatus provided in the embodiments of this application;

[0058] Figure 9 A structural block diagram of the device for determining the filtering apparatus provided in the embodiments of this application. Detailed Implementation

[0059] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0060] With the increasing adoption of automotive electronic intelligent driving domain controllers, the functions they support are becoming more powerful, and their power consumption is also gradually increasing. Switching power supplies, due to their high efficiency and widespread availability, are widely used in automotive electronic intelligent driving domain controllers. As the frequency and number of switching power supplies increase, switching noise has become a major source of conducted electromagnetic interference (EMI). In the conducted EMI interference testing of automotive electronic intelligent driving domain controllers, there are two methods: voltage method and current method. Because the current method involves more wiring harnesses under test, more levels of resistance, and lower limits, it is more difficult to overcome compared to the voltage method. Passing the current method test is an important prerequisite for completing the conducted EMI interference test of automotive electronic intelligent driving domain controllers.

[0061] In related technologies, different methods, such as grounding, shielding, and filtering, or a combination of these methods, can be used to solve the problem of domain controllers failing conducted EMI interference tests. Taking grounding as an example, modifications to the housing structure or adjustments to the printed circuit board layout can be made; taking filtering as an example, ready-made filters can be used. However, grounding methods involving modifications to the housing structure or adjustments to the printed circuit board layout are too drastic, have long completion cycles, and are inefficient. Using ready-made filters results in excessive size; because domain controllers have a fixed size, many functions and components, high component and wiring density, and limited remaining space within the housing, it is impossible to place the aforementioned filtering devices inside the domain controller, and the cost is high. How to quickly, effectively, and cost-efficiently pass conducted EMI interference tests on domain controllers is an urgent problem to be solved.

[0062] To address the aforementioned technical problems, the inventors of this application have discovered that, considering the complexity and low efficiency of grounding and shielding methods (grounding primarily provides a return path for noise sources that bypasses or minimizes external test networks, thus resolving EMI interference testing; however, grounding methods sometimes require modifications to the housing structure or adjustments to the printed circuit board layout, leading to high variability, complexity, and difficulty in forming a unified solution; shielding methods mainly involve shielding the noise source or the entire product; automotive electronic intelligent driving domain controllers are generally metal housing structures, already possessing shielding capabilities, but the metal structure has multiple connectors and cables that connect to the printed circuit board, leading internal noise to the external test network; due to the connector-led cables, shielding methods cannot completely shield internal noise. Separate shielding of the noise source also presents similar problems and places higher demands on the manufacturing process, making it difficult to promote), the research on filtering methods should be prioritized. Furthermore, considering the limitations of existing filtering methods (due to the fixed size of domain controllers, numerous functions and components, high component and wiring density, and insufficient space for filters, and the fact that most commercially available filters (mainly classified as active and passive filters; first-order and multi-order filters; RC, LC, and RLC filters, etc.) cannot be directly placed within automotive electronic intelligent driving domain controllers due to size constraints), the research on filtering methods focuses on self-built filters. Additionally, considering that the current-based conducted EMI interference test for automotive electronic intelligent driving domain controllers uses a Class 3 standard, with relatively high limits and large margins in the 150kHz to 50MHz spectrum, the exceedances generally occur in the 50MHz to 245MHz spectrum, which is dominated by common-mode noise. Therefore, common-mode inductors can be used as the primary component, and the parameters of the common-mode inductors can be selected specifically based on the current-based conducted EMI interference test results, thereby achieving rapid, effective, and low-cost conducted EMI interference testing of domain controllers.

[0063] The technical solutions of this application will be described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0064] Figure 1 A flowchart illustrating the method for determining the filtering device provided in the embodiments of this application. Figure 1 .like Figure 1 As shown, the method includes:

[0065] 101. Obtain the first test result; the first test result is obtained by conducting EMI interference tests on the first domain controller based on the current method.

[0066] The execution subject in this embodiment can be a terminal device with data processing capabilities, such as a computer or tablet.

[0067] In practical applications, the terminal device can connect to the conducted EMI interference testing equipment to obtain the first test result, and can also download the uploaded and stored first test result from the cloud server via the network.

[0068] 102. Based on the first test results, determine the first out-of-range frequency range of the first domain controller.

[0069] Specifically, the terminal device extracts the range of out-of-standard frequency points of the first domain controller from the first test results.

[0070] The first range of out-of-standard frequencies must include at least one out-of-standard frequency. An out-of-standard frequency is one that exceeds the standard value. In a broader definition, if there is a margin requirement in the test, frequencies with insufficient margin (below a preset threshold) can also be classified as out-of-standard frequencies. For example, for a certain frequency, such as 100MHz, if the EMI standard value is -5dBuA and the preset threshold for the margin requirement is 3dBuA, then an EMI value of -8dBuA or higher indicates that the frequency has insufficient margin.

[0071] 103. Determine the rated current of the common-mode inductor based on the actual input current of the first domain controller.

[0072] Specifically, if the terminal device obtains the actual input current of the first domain controller, such as 3A, then the rated current of the common mode inductor can be set to be greater than or equal to 3A.

[0073] 104. Determine the first AC resistance of the common-mode inductor based on the over-limit value corresponding to the first over-limit frequency range and the first over-limit frequency range.

[0074] In this embodiment, the AC resistor can be selected based on the spectral characteristics of the domain controller. For example, based on the spectral characteristics, a resistance range of 100Ω-1000Ω corresponds to the frequency range of 50MHz-245MHz. When determining the first AC resistor, since a larger resistance value results in a larger common-mode inductor size, a lower resistance value can be selected to ensure that the size meets the space requirements of the domain controller.

[0075] The first out-of-range value refers to the amount by which the EMI value at the out-of-range frequency exceeds the standard value. For example, if the EMI value is 10 dBuA and the standard value is 7 dBuA, then the out-of-range value is 10 - 7 = 3 dBuA.

[0076] Specifically, in one possible implementation, the terminal device can pre-store the correspondence between the out-of-range value and the corresponding frequency point, and the AC resistance of the common-mode inductor. Based on this correspondence, after obtaining the first out-of-range frequency range, the first AC resistance of the common-mode inductor can be selected based on the frequency point with the highest frequency in the first out-of-range frequency range and the corresponding out-of-range value. In another possible implementation, in response to the resistance value input by the user based on the first out-of-range frequency range and the corresponding out-of-range value, the resistance value can be determined as the first AC resistance of the common-mode inductor.

[0077] 105. Determine the target size of the common-mode inductor based on the spatial dimensions of the first domain controller.

[0078] In this embodiment, the spatial dimensions of the first domain controller determine the maximum design size of the common-mode inductor. The target size of the common-mode inductor should be smaller than the spatial dimensions of the first domain controller.

[0079] 106. The common-mode inductor is designated as the first filter device for the first domain controller, so as to perform conducted EMI filtering on the first domain controller through the first filter device.

[0080] Specifically, after determining the rated current, AC resistance, and target size of the common-mode inductor, a suitable common-mode inductor can be selected from a pre-stored pool of alternative models to serve as the first filter device for the first domain controller.

[0081] For example, such as Figure 2 As shown, the first filter device 201 can be connected to the input terminal of the switching power supply 2021 of the first domain controller 202 to perform conducted EMI filtering on the first domain controller 202 through the first filter device 201.

[0082] In this embodiment, other parameters of the common-mode inductor, such as withstand voltage and rated voltage, can be determined in conjunction with other test requirements.

[0083] To clearly explain the determination principle of the filter device, the following will combine... Figure 3 Provide an example.

[0084] For example, consider an automotive electronic intelligent driving domain controller operating at a 12V / 24V compatible voltage with a power consumption of 50W. The results of the current-based conducted interference test are as follows: Figure 3As shown, the horizontal axis of the coordinate system represents the frequency value of the conducted EMI interference signal, and the vertical axis represents the measured value corresponding to each frequency point. The figure shows, from top to bottom, a first straight line graph, a second straight line graph, a first curve graph, and a second curve graph. The first straight line graph represents the peak limit, the second straight line graph represents the mean limit, the first curve graph represents the peak value, and the second curve graph represents the mean value. The figure shows that there is a double-shoulder over-limit envelope around 50MHz, over-limit frequencies or frequencies with insufficient margin around 100MHz, and also an over-limit envelope around 200MHz. Based on the above test results, the over-limit frequencies are mainly concentrated in the 45MHz to 200MHz frequency band. Within this frequency band, based on the actual circuit usage of the domain controller, a common-mode inductor with a rated current ≥3A@24V and an impedance of 100 ohms@45M-200M is selected. Therefore, the rated voltage ≥300V and the size ≤20*12*15mm are required according to the space requirements of the domain controller. A common-mode inductor that meets the above parameter requirements is connected in series in the circuit to filter conducted EMI from the domain controller.

[0085] The method for determining the filtering device provided in this embodiment selects a common-mode inductor as the filtering device based on the AC method conducted EMI interference test results, and further determines the parameter values ​​of the common-mode inductor based on the test results. This method enables fast, effective and low-cost EMI interference testing conducted through a domain controller.

[0086] Figure 4 A flowchart illustrating the method for determining the filtering device provided in the embodiments of this application. Figure 2 .like Figure 4 As shown, in Figure 1 Based on the illustrated embodiment, this embodiment provides a detailed description of a further filtering scheme after selecting the common-mode inductor. After step 106, it may further include:

[0087] 401. Obtain the second test result; the second test result is obtained by conducting EMI interference test on the second domain controller based on the current method; the second domain controller is obtained by connecting the first filter device to the input terminal of the switching power supply of the first domain controller.

[0088] For example, such as Figure 2 As shown, the second domain controller 20 includes a first filter device 201 and a first domain controller 202. The first filter device 201 is connected to the switching power supply 2021 in the first domain controller 202.

[0089] 402. Based on the second test results, determine the range of the second out-of-range frequency points of the second domain controller.

[0090] 403. Based on the second out-of-range frequency point, adjust the first filter device to obtain a second filter device for the first domain controller, so as to perform conducted EMI filtering on the first domain controller through the second filter device.

[0091] In some embodiments, adjusting the first filter device according to the second out-of-range frequency point to obtain the second filter device for the first domain controller may include: determining the second AC resistance of the common-mode inductor according to the out-of-range value in the second out-of-range frequency point range; selecting a new common-mode inductor according to the second AC resistance; and determining the new common-mode inductor as the second filter device for the first domain controller if the size of the new common-mode inductor is smaller than the space size.

[0092] Optionally, determining the second AC resistance of the common-mode inductor based on the excess value within the second excess frequency range may include: if the rated current of the common-mode inductor is less than a preset threshold, then determining the second AC resistance of the common-mode inductor based on the excess value within the second excess frequency range.

[0093] In some embodiments, adjusting the first filter device according to the second out-of-range frequency point range to obtain the second filter device for the first domain controller may include: determining the rated current of the inductor bead according to the rated current of the common-mode inductor; determining the third AC resistance of the inductor bead according to the out-of-range value and the second out-of-range frequency point range; and connecting the inductor bead in series with the rear end of the common-mode inductor to obtain the second filter device for the first domain controller.

[0094] Specifically, after selecting a common-mode inductor as the first filter device, if the conducted EMI interference test results based on the current method of the first domain controller with the first filter device still show frequency points exceeding the standard, the AC resistance of the common-mode inductor can be changed. For example, the current common-mode inductor can be replaced with a common-mode inductor with a larger resistance value, so that the test can be performed again based on the new common-mode inductor.

[0095] It should be noted that the higher the AC resistance of the common-mode inductor, the higher the requirements for the number of turns, size, and permeability of the core material. Therefore, the decision to replace it with a common-mode inductor with a higher impedance value should be made based on the characteristics of the common-mode inductor being used, the available space, and the results of conducted EMI interference tests. Furthermore, for common-mode inductors with a rated current greater than the preset value, further increasing the AC resistance may require significant modifications to the rated voltage, inductor size, or core material, potentially violating the space constraints of the domain controller. Therefore, if... Figure 5In the third domain controller 501 shown, an inductor bead 202 can be directly connected in series at the end of the first filter device 201 (the original common-mode inductor) to form a simple combination of common-mode inductor / bead. One end of the inductor bead 202 is connected to the first filter device 201, and the other end is connected to the switching power supply 2021 in the first domain controller 202 to solve the problem of exceeding the standard in the current-based conducted EMI interference test.

[0096] 404. Obtain the third test result; the third test result is obtained by conducting EMI interference test on the third domain controller based on the current method; the third domain controller is obtained by connecting the second filter device to the input terminal of the switching power supply of the first domain controller.

[0097] 405. Based on the third test results, determine whether the third domain controller has an out-of-range frequency. If not, proceed to step 406; if so, proceed to step 407.

[0098] 406. The second filter device is determined as the final filter device.

[0099] 407. Based on the out-of-range value of the out-of-range frequency point of the third domain controller and the out-of-range frequency point of the third domain controller, adjust the second filter device to obtain the third filter device, so as to perform conducted EMI filtering on the first domain controller through the third filter device.

[0100] Specifically, after obtaining the third domain controller, the test equipment can be controlled to perform the current-based conducted EMI interference test again to obtain the third test result. If the third test result does not show any frequency exceeding the standard, the test is complete. If the frequency still exceeds the standard, the method described in the above embodiment can be used to add ferrite beads or adjust the common-mode inductor, etc., until the new filter device obtained after adjustment enables the domain controller to pass the conducted EMI interference test.

[0101] To clearly explain the determination principle of the filter device, the following will combine... Figure 6 and Figure 7 Provide an example.

[0102] like Figure 6 As shown, most out-of-range frequencies were suppressed, with only those around 100MHz remaining. Increasing the impedance of the common-mode inductor around 100MHz could suppress these out-of-range frequencies. However, for common-mode inductors with large rated currents, further increasing the impedance would require significant modifications to the rated voltage, inductor size, or core material, making it not the optimal solution. Therefore, for frequencies around 100MHz, an inductor bead with a rated current ≥3A and an impedance ≥200Ω@100MHz was added in series with the common-mode inductor and tested again, yielding the following results: Figure 7 The test results shown are as follows: Figure 7As shown, the combination of common-mode inductor and ferrite bead can effectively solve the problem of excessive frequency of current-based conducted interference while saving space and having a simple structure, and it also has a large margin.

[0103] It should be noted that, in the embodiments of this application... Figure 3 , Figure 6 as well as Figure 7 The grayscale of each line is only used to distinguish different curves and does not affect the protection range.

[0104] The method for determining the filtering device provided in this embodiment first selects the parameters of the common-mode inductor, and then selects a common-mode inductor or a combination of common-mode inductor and ferrite bead with suitable parameters. Compared with the complex methods of separate grounding and multi-stage filter combination, it can effectively solve the problem of excessive frequency of conducted interference by current method. The conducted EMI filtering device of this embodiment has a simple structure, low cost, and is easy to install in the limited space of the domain controller. It is fundamentally different from the current method of large-volume multi-stage filter and has great advantages in effectiveness and efficiency.

[0105] Based on the power consumption, spectral characteristics, and margin requirements of the domain controller, a common-mode inductor or a simple combination of common-mode inductor / ferrite bead with appropriate size and parameters is selected to solve the problem of exceeding the frequency limit in the current-method conducted EMI interference test of automotive electronic intelligent driving domain controllers, which is currently quite difficult, and can be successfully installed in the controller.

[0106] Figure 8 This is a schematic diagram of the structure of the filtering device provided in the embodiments of this application. (See attached diagram.) Figure 8 As shown, the determining device 80 of the filtering device includes: an acquisition module 801 and a processing module 802.

[0107] The acquisition module 801 is used to acquire the first test result; the first test result is obtained by conducting conducted EMI interference tests on the first domain controller based on the current method.

[0108] The processing module 802 is used to determine the first out-of-range frequency point range of the first domain controller based on the first test result; determine the rated current of the common-mode inductor based on the actual input current of the first domain controller; determine the first AC resistance of the common-mode inductor based on the out-of-range value corresponding to the first out-of-range frequency point range and the first out-of-range frequency point range; determine the target size of the common-mode inductor based on the spatial dimensions of the first domain controller; and determine the common-mode inductor as the first filter device of the first domain controller, so as to perform conducted EMI filtering on the first domain controller through the first filter device.

[0109] The filtering device determination device provided in this application selects a common-mode inductor as a filtering device based on the AC method conducted EMI interference test results, and further determines the parameter value of the common-mode inductor based on the test results, which can achieve fast, effective and low-cost conducted EMI interference test through the domain controller.

[0110] The device for determining the filtering device provided in this application embodiment can be used to execute the above method embodiment. Its implementation principle and technical effect are similar, and will not be repeated here.

[0111] This application embodiment also provides a filtering device, including: a first filtering device;

[0112] The first filtering device includes:

[0113] A common-mode inductor is connected to the input terminal of the switching power supply of the first domain controller to perform conducted EMI filtering on the first domain controller.

[0114] The target size of the common-mode inductor is determined based on the spatial dimensions of the first domain controller; the rated current of the common-mode inductor is determined based on the actual input current of the first domain controller; the first AC resistance of the common-mode inductor is determined based on the out-of-range value corresponding to the first out-of-range frequency range and the first out-of-range frequency range; the first out-of-range frequency range of the first domain controller is determined based on the first test result; the first test result is obtained by conducting EMI interference tests on the first domain controller based on the current method.

[0115] Optionally, the filtering device may include: a second filtering device;

[0116] The second filter device is obtained by adjusting the first filter device according to the second out-of-range frequency point;

[0117] The second out-of-range frequency range of the second domain controller is determined based on the second test results; the second test results are obtained by conducting conducted EMI interference tests on the second domain controller using the current method; the second domain controller is obtained by connecting the first filter device to the input terminal of the switching power supply of the first domain controller.

[0118] Optionally, the second filter is determined based on the new common-mode inductor when the size of the new common-mode inductor is smaller than the space size; the new common-mode inductor is selected based on the second AC resistance; the second AC resistance of the common-mode inductor is determined based on the out-of-range value within the second out-of-range frequency range.

[0119] Optionally, the second AC resistance of the common-mode inductor is determined based on the excess value within the second excess frequency range when the rated current of the common-mode inductor is less than a preset threshold.

[0120] Optionally, the second filtering device of the first domain controller is obtained by connecting an inductor bead in series with the end of the common-mode inductor, and the third AC resistance of the inductor bead is determined based on the over-limit value and the second over-limit frequency range within the second over-limit frequency range; the rated current of the inductor bead is determined based on the rated current of the common-mode inductor.

[0121] Optionally, the filtering device may also include a third filtering device;

[0122] The third filter device was obtained by adjusting the second filter device based on the out-of-range value and the out-of-range frequency of the third domain controller when there was an out-of-range frequency point in the third domain controller; the third test result was obtained by conducting EMI interference test on the third domain controller based on the current method; the third domain controller was obtained by connecting the second filter device to the input terminal of the switching power supply of the first domain controller.

[0123] The filtering device provided in this application embodiment is obtained by performing the above-described method embodiment. Its implementation principle and technical effect are similar, and will not be described again here.

[0124] Figure 9 This is a structural block diagram of the device used to determine the filtering apparatus provided in the embodiments of this application. The device may be a computer, a tablet device, etc.

[0125] The device 90 may include one or more of the following components: a processing component 901, a memory 902, a power supply component 903, a multimedia component 904, an audio component 905, an input / output (I / O) interface 906, a sensor component 907, and a communication component 908.

[0126] Processing component 901 typically controls the overall operation of device 90, such as operations associated with display, telephone calls, data communication, camera operation, and recording. Processing component 901 may include one or more processors 909 to execute instructions to complete all or part of the steps of the methods described above. Furthermore, processing component 901 may include one or more modules to facilitate interaction between processing component 901 and other components. For example, processing component 901 may include a multimedia module to facilitate interaction between multimedia component 904 and processing component 901.

[0127] Memory 902 is configured to store various types of data to support the operation of device 90. Examples of such data include instructions for any application or method operating on device 90, contact data, phonebook data, messages, pictures, videos, etc. Memory 902 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk.

[0128] Power supply component 903 provides power to the various components of device 90. Power supply component 903 may include a power management system, one or more power sources, and other components associated with generating, managing, and distributing power to device 90.

[0129] Multimedia component 904 includes a screen that provides an output interface between device 90 and the user. In some embodiments, the screen may include a liquid crystal display (LCD) and a touch panel (TP). If the screen includes a touch panel, the screen may be implemented as a touchscreen to receive input signals from the user. The touch panel includes one or more touch sensors to sense touches, swipes, and gestures on the touch panel. The touch sensors may sense not only the boundaries of touch or swipe actions but also the duration and pressure associated with the touch or swipe operation. In some embodiments, multimedia component 904 includes a front-facing camera and / or a rear-facing camera. When device 90 is in an operating mode, such as a shooting mode or a video mode, the front-facing camera and / or rear-facing camera may receive external multimedia data. Each front-facing camera and rear-facing camera may be a fixed optical lens system or have focal length and optical zoom capabilities.

[0130] Audio component 905 is configured to output and / or input audio signals. For example, audio component 905 includes a microphone (MIC) configured to receive external audio signals when device 90 is in an operating mode, such as call mode, recording mode, and voice recognition mode. The received audio signals may be further stored in memory 902 or transmitted via communication component 908. In some embodiments, audio component 905 also includes a speaker for outputting audio signals.

[0131] I / O interface 906 provides an interface between processing component 901 and peripheral interface modules, such as keyboards, click wheels, buttons, etc. These buttons may include, but are not limited to, home buttons, volume buttons, power buttons, and lock buttons.

[0132] Sensor assembly 907 includes one or more sensors for providing state assessments of various aspects of device 90. For example, sensor assembly 907 may detect the on / off state of device 90, the relative positioning of components such as the display and keypad of device 90, changes in the position of device 90 or a component of device 90, the presence or absence of user contact with device 90, the orientation or acceleration / deceleration of device 90, and temperature changes of device 90. Sensor assembly 907 may include a proximity sensor configured to detect the presence of nearby objects without any physical contact. Sensor assembly 907 may also include an optical sensor, such as a CMOS or CCD image sensor, for use in imaging applications. In some embodiments, sensor assembly 907 may also include an accelerometer, a gyroscope, a magnetometer, a pressure sensor, or a temperature sensor.

[0133] Communication component 908 is configured to facilitate wired or wireless communication between device 90 and other devices. Device 90 can access wireless networks based on communication standards, such as WiFi, 2G, or 3G, or combinations thereof. In one exemplary embodiment, communication component 908 receives broadcast signals or broadcast-related information from an external broadcast management system via a broadcast channel. In one exemplary embodiment, communication component 908 also includes a near-field communication (NFC) module to facilitate short-range communication. For example, the NFC module may be implemented based on radio frequency identification (RFID) technology, Infrared Data Association (IrDA) technology, ultra-wideband (UWB) technology, Bluetooth (BT) technology, and other technologies.

[0134] In an exemplary embodiment, the apparatus 90 may be implemented by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic components to perform the methods described above.

[0135] In an exemplary embodiment, a non-transitory computer-readable storage medium including instructions is also provided, such as a memory 902 including instructions, which can be executed by a processor 909 of the device 90 to perform the above-described method. For example, the non-transitory computer-readable storage medium may be a ROM, random access memory (RAM), CD-ROM, magnetic tape, floppy disk, and optical data storage device, etc.

[0136] The aforementioned computer-readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. The readable storage medium can be any available medium accessible to a general-purpose or special-purpose computer.

[0137] An exemplary readable storage medium is coupled to a processor, enabling the processor to read information from and write information to the readable storage medium. Of course, the readable storage medium can also be a component of the processor. The processor and the readable storage medium can reside in an Application Specific Integrated Circuit (ASIC). Alternatively, the processor and the readable storage medium can exist as discrete components in the device.

[0138] Those skilled in the art will understand that all or part of the steps of the above-described method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments; and the aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0139] This application also provides a computer program product, including a computer program, which, when executed by a processor, implements a method for determining a filtering device executed by a device that implements the above-mentioned filtering device.

[0140] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method for determining a filtering device, characterized in that, include: Obtain the first test result; The first test result was obtained by conducting EMI interference tests on the first domain controller using the current method. Based on the first test results, determine the first out-of-range frequency point range of the first domain controller; The rated current of the common-mode inductor is determined based on the actual input current of the first domain controller; The first AC resistance of the common-mode inductor is determined based on the excess value corresponding to the first excess frequency range and the first excess frequency range. The target size of the common-mode inductor is determined based on the spatial dimensions of the first domain controller; The common-mode inductor is designated as the first filter device for the first domain controller, so as to perform conducted EMI filtering on the first domain controller through the first filter device; The method further includes: Obtain the second test result; the second test result is obtained by conducting EMI interference test on the second domain controller based on the current method; the second domain controller is obtained by connecting the first filter device to the input terminal of the switching power supply of the first domain controller; Based on the second test results, determine the range of the second out-of-range frequency points for the second domain controller; The second AC resistance of the common-mode inductor is determined based on the excess value within the second excess frequency range; Based on the second AC resistance, select a new common-mode inductor; If the size of the new common-mode inductor is smaller than the space size, then the new common-mode inductor is determined as the second filter device of the first domain controller, so as to perform conducted EMI filtering on the first domain controller through the second filter device.

2. The method according to claim 1, characterized in that, The step of determining the second AC resistance of the common-mode inductor based on the exceeding value within the second exceeding frequency range includes: If the rated current of the common-mode inductor is less than a preset threshold, then the second AC resistance of the common-mode inductor is determined based on the excess value within the second excess frequency range.

3. The method according to claim 1, characterized in that, The step of adjusting the first filtering device according to the second out-of-range frequency point to obtain a second filtering device for the first domain controller includes: The rated current of the inductor bead is determined based on the rated current of the common mode inductor. The third AC resistance of the inductive bead is determined based on the excess value within the second excess frequency range and the second excess frequency range. The inductor bead is connected in series with the rear end of the common-mode inductor to obtain the second filtering device of the first domain controller.

4. The method according to any one of claims 1-3, characterized in that, The method further includes: Obtain the third test result; the third test result is obtained by conducting EMI interference test on the third domain controller based on the current method; the third domain controller is obtained by connecting the second filter device to the input terminal of the switching power supply of the first domain controller; Based on the third test results, determine whether the third domain controller has any frequency points exceeding the standard. If there are no out-of-range frequency points in the third domain controller, then the second filtering device will be determined as the final filtering device.

5. The method according to claim 4, characterized in that, The method further includes: If the third domain controller has an out-of-range frequency, the second filter device is adjusted according to the out-of-range value of the out-of-range frequency of the third domain controller and the out-of-range frequency of the third domain controller to obtain a third filter device, so as to perform conducted EMI filtering on the first domain controller through the third filter device.

6. A filtering device, characterized in that, include: A common-mode inductor is connected to the input terminal of the switching power supply of the first domain controller and is used to perform conducted EMI filtering on the first domain controller. The target size of the common-mode inductor is determined based on the spatial dimensions of the first domain controller; the rated current of the common-mode inductor is determined based on the actual input current of the first domain controller; the first AC resistance of the common-mode inductor is determined based on the out-of-range value corresponding to the first out-of-range frequency range and the first out-of-range frequency range; the first out-of-range frequency range of the first domain controller is determined based on the first test result; the first test result is obtained by conducting EMI interference tests on the first domain controller using the current method. The filtering device also includes: a second filtering device; The second filtering device is obtained by adjusting the first filtering device according to the second range of out-of-range frequencies; The second out-of-range frequency range of the second domain controller is determined based on the second test results; the second test results are obtained by conducting conducted EMI interference tests on the second domain controller using the current method; the second domain controller is obtained by connecting the first filter device to the input terminal of the switching power supply of the first domain controller. The second filtering device is determined based on the new common-mode inductor when the size of the new common-mode inductor is smaller than the space size; the new common-mode inductor is selected based on the second AC resistance; the second AC resistance of the common-mode inductor is determined based on the out-of-range value within the second out-of-range frequency range.

7. A device for determining a filtering device, characterized in that, include: At least one processor and memory; The memory stores computer-executed instructions; The at least one processor executes computer execution instructions stored in the memory, causing the at least one processor to perform the method for determining the filtering device as described in any one of claims 1 to 5.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, implement the method for determining a filtering device as described in any one of claims 1 to 5.

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