Impedance matching method and device, electronic equipment and storage medium

Abstract

The invention relates to the technical field of vehicle control, and provides an impedance matching method and device, electronic equipment and a storage medium. According to the method, an electrical schematic diagram of a PEPS system is decomposed into an initial impedance matching circuit and a wireless receiver circuit module, communication parameters are determined based on a communication mode of the wireless receiver circuit module, and initial matching impedance and target matching impedance of the initial impedance matching circuit are determined according to the communication parameters; according to the method, the initial impedance matching circuit of the PEPS system is obtained, then circuit updating information from the initial matching impedance to the target matching impedance is determined in a Smith chart of the PEPS system, and finally the initial impedance matching circuit is modified according to the circuit updating information to obtain the impedance matching circuit of the PEPS system, so that more accurate impedance matching is realized for a radio frequency receiving module of the PEPS system. The radio frequency signal transmitting and receiving sensitivity is improved, the radio frequency signal loss is reduced, the probability of signal transmitting and receiving abnormity is reduced, and the user experience is improved.

Description

Technical Field

[0001] The present application relates to the field of vehicle control technology, and in particular to an impedance matching method, device, electronic device and storage medium. Background Art

[0002] In traditional cars, keyless entry and start are usually implemented by separate controllers. However, with the development of new energy vehicles, in order to reduce system complexity and cost, and improve system reliability and coordination capabilities, a large number of automobile manufacturers have incorporated keyless entry and start functions into regional controllers.

[0003] In this integrated design, since the regional controller incorporates multiple types of communication signals, such as CAN (Controller Area Network) signals, LIN (Local Interconnect Network) signals, ETH (Ethernet), etc., as well as switching signals such as motor drive signals, affected by the radiation emission of these signals, the RF transceiver sensitivity and loss of PEPS (Passive Entry Passive Start) need to be paid special attention to, so as to avoid high RF transceiver loss and low sensitivity due to improper design, which will further shorten the remote control distance and detection distance of keyless entry, affecting the user experience. Summary of the invention

[0004] In view of this, the embodiments of the present application provide an impedance matching method, device, electronic device and storage medium to solve the problem of control abnormality caused by reduced receiver sensitivity in the vehicle keyless entry and start system in the prior art.

[0005] In a first aspect of an embodiment of the present application, an impedance matching method is provided, the method being used to determine an impedance matching circuit of a keyless entry and start system, the method comprising:

[0006] Obtaining an electrical schematic diagram of the keyless entry start system, and obtaining an initial impedance matching circuit and a wireless receiver circuit module of the keyless entry system according to the electrical schematic diagram;

[0007] Determine communication parameters according to the communication mode of the wireless receiver circuit module, and determine the initial matching impedance and the target matching impedance of the initial impedance matching circuit according to the communication parameters;

[0008] Draw a Smith chart of the keyless entry start system, and determine circuit update information from an initial matching impedance to a target matching impedance in the Smith chart;

[0009] The initial impedance matching circuit is modified according to the circuit update information to obtain the impedance matching circuit of the keyless entry and start system.

[0010] According to a second aspect of the embodiments of the present application, an impedance matching device is provided, comprising:

[0011] An acquisition module is configured to acquire an electrical schematic diagram of the keyless entry start system, and obtain an initial impedance matching circuit and a wireless receiver circuit module of the keyless entry system according to the electrical schematic diagram;

[0012] A determination module is configured to determine a communication parameter according to a communication mode of the wireless receiver circuit module, and determine an initial matching impedance and a target matching impedance of the initial impedance matching circuit according to the communication parameter;

[0013] A drawing module is configured to draw a Smith chart of the keyless entry and start system, and determine circuit update information from an initial matching impedance to a target matching impedance in the Smith chart;

[0014] The matching module is configured to modify the initial impedance matching circuit according to the circuit update information to obtain the impedance matching circuit of the keyless entry and start system.

[0015] According to a third aspect of an embodiment of the present application, an electronic device is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above method when executing the computer program.

[0016] According to a fourth aspect of an embodiment of the present application, a computer-readable storage medium is provided, which stores a computer program, and when the computer program is executed by a processor, the steps of the above method are implemented.

[0017] Compared with the prior art, the embodiments of the present application have the following beneficial effects: the embodiments of the present application decompose the electrical schematic diagram of the PEPS system into an initial impedance matching circuit and a wireless receiver circuit module, determine the communication parameters based on the communication mode of the wireless receiver circuit module, and determine the initial matching impedance and the target matching impedance of the initial impedance matching circuit according to the communication parameters, and then determine the circuit update information from the initial matching impedance to the target matching impedance in the Smith chart of the PEPS system, and finally modify the initial impedance matching circuit according to the circuit update information to obtain the impedance matching circuit of the PEPS system, thereby achieving more accurate impedance matching for the RF receiving module of the PEPS system, improving the RF signal reception and transmission sensitivity of the PEPS system, reducing the RF signal loss, reducing the probability of abnormal signal reception and transmission of the PEPS system, and improving the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 It is a system block diagram of a zone controller integrated with a PEPS system.

[0020] Figure 2 It is a flow chart of an impedance matching method provided in an embodiment of the present application.

[0021] Figure 3 It is a schematic diagram of an electrical schematic diagram of a PEPS system provided in an embodiment of the present application.

[0022] Figure 4 It is a circuit diagram obtained by decomposing the electrical schematic diagram of the PEPS system provided in the embodiment of the present application.

[0023] Figure 5 It is a flow chart of another impedance matching method provided in an embodiment of the present application.

[0024] Figure 6 It is a flowchart of a method for determining a first target matching impedance of an initial impedance matching circuit according to communication parameters provided in an embodiment of the present application.

[0025] Figure 7 It is a flowchart of a method for determining a second target matching impedance of an initial impedance matching circuit according to communication parameters provided in an embodiment of the present application.

[0026] Figure 8 It is a system block diagram for indirectly matching a PEPS system provided in an embodiment of the present application.

[0027] Fig. 9 It is a system block diagram for conjugate matching of a PEPS system provided in an embodiment of the present application.

[0028] Fig.10 It is a flow chart of a method for determining an initial matching impedance of an initial impedance matching circuit according to communication parameters provided in an embodiment of the present application.

[0029] Fig.11 It is a flowchart of a method for determining circuit update information from an initial matching impedance to a target matching impedance in a Smith chart provided by an embodiment of the present application.

[0030] Fig.12 It is a schematic diagram of a Smith chart provided in an embodiment of the present application.

[0031] Fig.13 It is a schematic diagram of another Smith chart provided in an embodiment of the present application.

[0032] Fig.14 It is a flow chart of another impedance matching method provided in an embodiment of the present application.

[0033] Fig.15 It is a schematic diagram of an impedance matching device provided in an embodiment of the present application.

[0034] Fig.16 It is a schematic diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0035] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0036] An impedance matching method and device according to an embodiment of the present application will be described in detail below with reference to the accompanying drawings.

[0037] As mentioned above, in the integrated design, since the regional controller incorporates multiple types of communication signals, such as CAN signals, LIN signals, ETH, etc., as well as switching signals such as motor drive signals, and is affected by the radiation emission of these signals, the RF transceiver sensitivity and loss of the PEPS system need to be paid special attention to, so as to avoid high RF transceiver loss and low sensitivity due to improper design, which will further shorten the remote control distance and detection distance of the keyless entry, affecting the user experience.

[0038] Figure 1 This is a system block diagram of the zone controller integrated with the PEPS system. Figure 1 As shown, the zone controller can receive trigger signals sent by a door handle trigger module and a tailgate trigger module, wherein the door handle trigger module can include a door handle trigger module for a left front door and a door handle trigger module for a right front door.

[0039] After receiving the trigger signal, the zone controller can send the LF signal to the smart key through the LF (Low Frequency) sending module. The LF signal can be any of the following: left front or right front door PE (Passive Entry) antenna signal, armrest box PS (Passive Start) antenna signal, luggage box PS antenna signal, rear seat PS antenna signal, IMMO (Immobilization, engine anti-theft locking system) antenna signal.

[0040] After receiving the LF signal, the smart key can send a radio frequency control signal, such as opening the door, closing the door, starting the vehicle, etc. to the RF (Radio Frequency) receiving module. The RF receiving module receives the RF signal and executes the control command carried in the RF signal after verifying it.

[0041] That is to say, Figure 1 In the zone controller system shown, the zone controller is responsible for function logic processing, key positioning, LF antenna driving and RF signal reception; the smart key sends complex remote control commands and sends location signals; the LF antenna is responsible for sending LF signals. Furthermore, the start switch in the vehicle can be used to trigger the vehicle start, and the door handle can be used to trigger the unlock signal and send the LF signal. The triggering of the start switch and the door handle can be realized by the zone controller.

[0042] In one example, the working process of the regional controller is that when a user carries a smart key and appears in the detection range covered by the low-frequency antenna and pulls / presses the door opening button / one-button start button, the door handle / door opening button / one-button start button will wake up the regional controller and send a 125KHZ low-frequency trigger signal to the smart key through the LF antenna. After receiving the low-frequency trigger signal, the smart key sends a high-frequency unlocking signal or ignition signal (or presses the brake pedal) to the regional controller RF for reception. After receiving the high-frequency unlocking or ignition signal, the RF receiver verifies through encryption whether it is the key of the vehicle. If it is the key of the vehicle, it executes unlocking or ignition (new energy vehicles appear to issue a power request and can be operated in gear).

[0043] In addition, the smart key also has the RKE (Remote Keyless Entry) function, which means that the car can be unlocked / locked by pressing the key button within the effective range of the vehicle.

[0044] The entire PEPS operation process is related to the RF receiving path, so the sensitivity and field strength of the RF receiving path in the PEPS system need to be accurately matched to ensure that the sensitivity and loss of the RF receiver have sufficient margins. When affected by other signals in the zone controller, the RF receiver can still receive the signal correctly.

[0045] In view of this, an embodiment of the present application provides an impedance matching method, which decomposes the electrical schematic diagram of the PEPS system into an initial impedance matching circuit and a wireless receiver circuit module, determines the communication parameters based on the communication mode of the wireless receiver circuit module, and determines the initial matching impedance and the target matching impedance of the initial impedance matching circuit according to the communication parameters, and then determines the circuit update information from the initial matching impedance to the target matching impedance in the Smith chart of the PEPS system, and finally modifies the initial impedance matching circuit according to the circuit update information to obtain the impedance matching circuit of the PEPS system, thereby achieving more accurate impedance matching for the RF receiving module of the PEPS system, improving the RF signal reception and transmission sensitivity of the PEPS system, reducing the RF signal loss, reducing the probability of abnormal signal reception and transmission of the PEPS system, and improving the user experience.

[0046] Figure 2 is a flow chart of an impedance matching method provided in an embodiment of the present application. Figure 2 As shown, the method comprises the following steps:

[0047] In step S201, an electrical schematic diagram of a keyless entry and start system is obtained, and an initial impedance matching circuit and a wireless receiver circuit module of the keyless entry system are obtained according to the electrical schematic diagram.

[0048] In step S202, communication parameters are determined according to the communication mode of the wireless receiver circuit module, and initial matching impedance and target matching impedance of the initial impedance matching circuit are determined according to the communication parameters.

[0049] In step S203, a Smith chart of the keyless entry and start system is drawn, and circuit update information from the initial matching impedance to the target matching impedance is determined in the Smith chart.

[0050] In step S204, the initial impedance matching circuit is modified according to the circuit update information to obtain an impedance matching circuit of the keyless entry and start system.

[0051] In some embodiments of the present application, the impedance matching method may be executed by a terminal. Furthermore, an impedance matching tool may be configured in the terminal, and the impedance matching tool is used to implement the impedance matching method provided in the embodiments of the present application, that is, to determine a more accurate impedance matching circuit for the PEPS system.

[0052] In some implementations, the impedance matching tool can obtain an electrical schematic diagram of the PEPS system, and obtain an initial impedance matching circuit and a wireless receiver circuit module of the PEPS system based on the electrical schematic diagram. Furthermore, the communication parameters can be determined based on the communication mode of the wireless receiver circuit module, and then the initial matching impedance and the target matching impedance of the initial impedance matching circuit can be determined based on the communication parameters.

[0053] In one example, the model of the wireless receiver chip can be obtained according to the electrical schematic diagram of the PEPS system, and the communication mode and communication parameters of the PEPS system can be determined by querying the chip parameters of the signal.

[0054] According to the determined communication mode and communication parameters, a Smith chart of the PEPS system can be drawn. The circuit update information from the initial matching impedance to the target matching impedance can be determined by inputting the above initial matching impedance and the target matching impedance into the Smith chart. Finally, the initial impedance matching circuit is modified according to the circuit update information to obtain the impedance matching circuit of the keyless entry and start system.

[0055] According to the technical solution provided in the embodiment of the present application, the electrical schematic diagram of the PEPS system is decomposed into an initial impedance matching circuit and a wireless receiver circuit module, the communication parameters are determined based on the communication mode of the wireless receiver circuit module, and the initial matching impedance and the target matching impedance of the initial impedance matching circuit are determined according to the communication parameters, and then the circuit update information from the initial matching impedance to the target matching impedance is determined in the Smith chart of the PEPS system, and finally the initial impedance matching circuit is modified according to the circuit update information to obtain the impedance matching circuit of the PEPS system, thereby achieving more accurate impedance matching for the RF receiving module of the PEPS system, improving the RF signal reception and transmission sensitivity of the PEPS system, reducing the RF signal loss, reducing the probability of abnormal signal reception and transmission of the PEPS system, and improving the user experience.

[0056] Figure 3 is a schematic diagram of an electrical schematic diagram of a PEPS system provided in an embodiment of the present application, Figure 4 It is a circuit diagram obtained by decomposing the electrical schematic diagram of the PEPS system provided in the embodiment of the present application.

[0057] like Figure 3As shown, the PEPS system may include an antenna matching network, a SAW (Surface Acoustic Wave, surface acoustic wave filter), an RF receiver input matching network and an RF receiver. Among them, a pair of test points TPA and TPA-GND may be set at the input end of the antenna matching network, a pair of test points TPB and TPB-GND may be set at the input end of the SAW filter, a pair of test points TPC and TPC-GND may be set at the input end of the RF receiver input matching network, and a pair of test points TPD and TPD-GND may be set at the input end of the RF receiver.

[0058] right Figure 3 The electrical schematic diagram shown can be broken down to include the circuit of the antenna matching network and the circuit of the RF receiver input matching network. Figure 4 .like Figure 4 As shown, the antenna matching network circuit and the RF receiver input matching network circuit are both initial matching circuits. The antenna matching network circuit is composed of inductor L1, capacitor C1 and capacitor C2, and the RF receiver input matching network circuit is composed of resistors R1 and R2, inductor L2 and capacitor C3. Among them, the parameter values ​​of each component in the circuit, including inductor, capacitor and resistor, are determined according to actual needs and are not limited here.

[0059] That is, in some embodiments of the present application, the initial impedance matching circuit may include a first initial impedance matching circuit and a second initial impedance matching circuit, wherein the first initial impedance matching circuit is used to match the equivalent impedance of the antenna of the keyless entry start system, and the second initial impedance matching circuit is used to match the equivalent impedance of the wireless receiver circuit.

[0060] In some implementations, the communication mode of the PEPS system may include at least one of an RFID (Radio Frequency Identification) communication mode, a BLE (Bluetooth) communication mode, and an UWB (Ultra Wide Band) communication mode. Further, the communication parameters may include at least one of a bandwidth, a center frequency, a baud rate, and a frequency deviation.

[0061] Figure 5 is a flow chart of another impedance matching method provided in an embodiment of the present application. Figure 5 Step S501 in the illustrated embodiment is Figure 2 Step S201 in the illustrated embodiment is substantially the same, and Figure 5 Step S506 in the illustrated embodiment is Figure 2 Step S204 in the illustrated embodiment is substantially the same and will not be described in detail herein. Figure 5 As shown, the method also includes the following steps:

[0062] In step S502, a matching mode is determined according to a communication mode or a communication parameter.

[0063] Among them, the matching modes include indirect matching and conjugate matching.

[0064] In step S503, in response to determining that the matching mode is indirect matching, an initial matching impedance and a first target matching impedance of the initial impedance matching circuit are determined according to the communication parameters.

[0065] In step S504, in response to determining that the matching mode is conjugate matching, an initial matching impedance and a second target matching impedance of the initial impedance matching circuit are determined according to the communication parameters.

[0066] In step S505 , a Smith chart of the keyless entry and start system is drawn, and circuit update information from the initial matching impedance to the first or second target matching impedance is determined in the Smith chart.

[0067] In some embodiments of the present application, the matching mode of the wireless receiver circuit module in the PEPS system can be determined according to the communication mode or communication parameters of the wireless receiver circuit module. The matching mode can be indirect matching or conjugate matching. In one example, the user can determine the matching mode based on the communication mode or communication parameters according to experience, or train a matching mode prediction model using historical matching data, and then use the trained model to predict the PEPS system to determine its matching mode.

[0068] If the determined matching mode is indirect matching, the initial matching impedance and the first target matching impedance of the initial impedance matching circuit can be determined according to the communication parameters. Alternatively, if the determined matching mode is conjugate matching, the initial matching impedance and the second target matching impedance of the initial impedance matching circuit can be determined according to the communication parameters. The first target matching impedance and the second target matching impedance are determined in different ways.

[0069] Further, after drawing the Smith chart of the PEPS system, the circuit update information from the initial matching impedance to the first or second target matching impedance can be determined in the Smith chart. For example, if the determined matching mode is indirect matching, the circuit update information from the initial matching impedance to the first target matching impedance can be determined in the Smith chart. Alternatively, if the determined matching mode is conjugate matching, the circuit update information from the initial matching impedance to the second target matching impedance can be determined in the Smith chart.

[0070] Figure 6 1 is a flow chart of a method for determining a first target matching impedance of an initial impedance matching circuit according to communication parameters provided in an embodiment of the present application. Figure 6As shown, the method comprises the following steps:

[0071] In step S601, the signal loss rate and receiving sensitivity of the keyless entry and start system are determined according to the communication parameters.

[0072] In step S601, a matching impedance corresponding to a target signal loss rate and a receiving sensitivity combination is determined as a first target matching impedance.

[0073] The target signal loss rate and receiving sensitivity combination includes a signal loss rate lower than a preset loss rate threshold and a receiving sensitivity higher than a preset sensitivity threshold.

[0074] In some embodiments of the present application, in the indirect matching mode, the signal loss rate and receiving sensitivity of the PEPS system can be determined according to the communication parameters, and then the matching impedance corresponding to the target signal loss rate and receiving sensitivity combination is determined as the first target matching impedance.

[0075] For example, when the signal loss rate satisfies a preset loss rate threshold, the signal loss rate and the corresponding maximum receiving sensitivity are combined to determine the target signal loss rate and receiving sensitivity combination. Alternatively, when the receiving sensitivity satisfies a preset sensitivity threshold, the receiving sensitivity and the corresponding minimum signal loss rate are determined to be the target signal loss rate and receiving sensitivity combination.

[0076] For example, if the determined communication mode is the RFID communication mode, the characteristic impedances of the coaxial cables based on RFID, which usually have high power transmission and low loss, are 30 ohms and 77 ohms, respectively. The power that can be transmitted by the 30 ohm coaxial cable is the largest, and the signal transmission loss of the 77 ohm coaxial cable is the smallest. The arithmetic mean of 30 ohms and 77 ohms is 53.5 ohms, and the geometric mean of 30 ohms and 77 ohms is 48 ohms. Based on engineering considerations, in order to meet the maximum power transmission and minimum loss as much as possible, 53.5 ohms and 48 ohms can be compromised to 50 ohms. That is, the determined first target matching impedance can be 50 ohms.

[0077] Figure 7 1 is a flow chart of a method for determining a second target matching impedance of an initial impedance matching circuit according to communication parameters provided in an embodiment of the present application. Figure 7 As shown, the method comprises the following steps:

[0078] In step S701, the communication frequency among the communication parameters is acquired.

[0079] In step S702 , a first initial equivalent impedance between an antenna of a keyless entry and start system and a first initial impedance matching circuit at a communication frequency is calculated.

[0080] In step S703, the conjugate impedance of the first initial equivalent impedance is determined as the second target matching impedance.

[0081] In some embodiments of the present application, in the conjugate matching mode, the communication frequency in the communication parameters can be obtained, the first initial equivalent impedance of the antenna of the PEPS system and the first initial impedance matching circuit at the communication frequency can be calculated, and the conjugate impedance of the first initial equivalent impedance can be used as the second target matching impedance.

[0082] Figure 8 1 is a system block diagram of an indirect matching system for a PEPS system provided by an embodiment of the present application. Figure 8 As shown, at this time, the front-stage module of the PEPS system can be an antenna module, the front-stage matching network can be an antenna matching network, the rear-stage module can be an RF receiver module, and the rear-stage matching network can be a matching network of the RF receiver.

[0083] If the communication mode of the RF receiver of the PEPS system is RFID mode, then the signal reflection loss is minimum and the sensitivity is highest under the matching impedance of 50 ohms according to the communication parameters such as the center frequency of 433.92 MHz and bandwidth in the communication mode. At this time, the equivalent impedance of the pre-matching network and the post-matching network can be matched to 50 ohms respectively to achieve impedance matching of the PRPS system.

[0084] Fig. 9 1 is a system block diagram of a conjugate matching system for a PEPS system provided in an embodiment of the present application. Fig. 9 As shown, the front-stage module of the PEPS system may be an antenna module and an antenna matching network, the rear-stage module may be an RF receiver, and the matching network may be a matching network of the RF receiver.

[0085] If the communication mode of the RF receiver of the PEPS system is UWB mode, the key parameters such as the center frequency, bandwidth, baud rate and frequency deviation of UWB can be obtained by querying the RF receiver chip model. Furthermore, the initial impedance of the front-stage module can be determined according to the center frequency, for example, C+jD, and the initial impedance of the matching network can be determined to be E+jF. At this time, the target impedance of the matching network can be determined to be C-jD, that is, the impedance of the matching network needs to be matched from E+jF to C-jD.

[0086] Fig.10 1 is a flow chart of a method for determining an initial matching impedance of an initial impedance matching circuit according to communication parameters provided in an embodiment of the present application. Fig.10 As shown, the method comprises the following steps:

[0087] In step S1001, the communication frequency among the communication parameters is acquired.

[0088] In step S1002, a second initial equivalent impedance of the first initial matching circuit at the communication frequency and a third initial equivalent impedance of the second initial matching circuit at the communication frequency are calculated.

[0089] In step S1003, the second initial equivalent impedance and the third initial equivalent impedance are determined as initial matching impedances.

[0090] In some embodiments of the present application, when determining the initial matching impedance of the initial impedance matching circuit, the communication frequency in the communication parameters may be first obtained, and then the second initial equivalent impedance of the first initial matching circuit at the communication frequency and the third initial equivalent impedance of the second initial matching circuit at the communication frequency are calculated. Finally, the second initial equivalent impedance and the third initial equivalent impedance are determined as the initial matching impedance.

[0091] In some embodiments, if the PEPS system after impedance matching still has problems of low sensitivity or excessive signal loss during testing or use, the impedance matching circuit can be adjusted again. In one example, the initial matching impedance can be obtained by testing with a tester to improve the defect that the ideal initial matching impedance value directly calculated in the above method may have a large deviation from the actual value. Then, the initial matching impedance obtained by actual measurement is matched with the target matching impedance in the Smith chart to determine the circuit update information, and then determine the modified impedance matching circuit.

[0092] Fig.11 1 is a flow chart of a method for determining circuit update information from an initial matching impedance to a target matching impedance in a Smith chart provided by an embodiment of the present application. Fig.11 As shown, the method comprises the following steps:

[0093] In step S1101 , a path from an initial matching impedance to a target matching impedance along an arc of at least one target circle is determined in a Smith chart.

[0094] In step S1102 , circuit update information is determined according to the arc direction and arc length included in the path.

[0095] The circuit update information includes at least one of the following: the type of components to be added, the connection method of the added components in the initial impedance matching circuit, the parameter values ​​of the added components, and the parameter values ​​of the modified parameters of the existing components.

[0096] The basic principle of the Smith chart is to represent the input impedance of the transmission line based on the reflection coefficient on the complex plane. In a microwave transmission line, reflection occurs when a signal encounters an impedance mismatch. The reflection coefficient (Γ) is a complex number, whose modulus represents the amplitude of the reflected wave, and the argument represents the phase difference of the reflected wave relative to the incident wave. The Smith chart uses the real and imaginary parts of the reflection coefficient as coordinates to map different impedance points onto the chart, so that the impedance changes can be intuitively seen.

[0097] The Smith chart consists of a series of equal reflection coefficient circles, equal conductance circles, and equal resistance circles. These circles intersect in different ways to form a unique pattern on the complex plane. Each point on the circle chart represents a specific impedance value. By reading the coordinates of the point, we can quickly obtain the corresponding impedance information. When impedance matching is required, a path from the source impedance to the matching point (such as 50 ohm impedance) can be determined based on the position of the source impedance and the load impedance on the circle chart. This path can be achieved by adding inductors, capacitors and other components to the circuit. For example, moving along the equal resistance circle can change the reactance value by connecting an inductor or capacitor in series; moving along the equal reactance circle can change the resistance value by connecting an inductor or capacitor in parallel. According to the change pattern on the matching path, appropriate inductor and capacitor components can be selected to achieve impedance matching.

[0098] In this way, determining the circuit update information from the initial matching impedance to the target matching impedance in the Smith chart can be to determine the path from the initial matching impedance to the target matching impedance along the arc of at least one target circle in the Smith chart, and determine the circuit update information based on the arc direction and arc length included in the path.

[0099] Fig.12 and Fig.13 is a schematic diagram of the Smith chart provided in the embodiment of the present application. In one example, if the initial matching impedance of the TPB point of the PEPS system is determined to be 17-154j, the initial matching impedance can be Fig.12 Input the Smith chart shown in the figure to obtain the initial matching circuit. Fig.12 As shown, the initial matching circuit includes a resistor element Z L .

[0100] Furthermore, the target impedance can be matched to 50 ohm input Fig.12 The Smith chart shown in Fig.13 The Smith chart shown shows the point TP3 that is closest to 50 ohms. Fig.13 The Smith chart shown also includes the point DP1 corresponding to the initial matching impedance and the point TP2 that needs to be passed from the point DP1 to the point TP3.

[0101] That is to say, Fig.13 In the Smith chart shown, point DP1 is displaced to point TP2 via the first arc segment, and the impedance value of point TP2 is 17+23.76j. This displacement can be achieved by connecting a 10.2 pF capacitor in parallel in the impedance matching circuit. Further, point TP2 is displaced to point TP3 via the second arc segment, and the impedance value of point TP3 is 50.227-0.273. This displacement requires connecting a 65.2 nanohenry inductor in parallel in the impedance matching circuit. In this way, we can get Fig.13 The modified impedance matching circuit described in .

[0102] In some implementations, the modified impedance matching circuit can be directly used as the impedance matching circuit of the PEPS system. Alternatively, since a capacitor with a standard capacitance value and an inductor with a standard inductance value need to be selected in actual engineering implementation, a capacitor with a capacitance of 10 pF and an inductor with a capacitance of 65 nanohenry can be selected and added to the initial impedance matching circuit respectively to obtain the final impedance matching circuit.

[0103] Fig.14 FIG. 1 is a flow chart of another impedance matching method provided in an embodiment of the present application. Fig.14 As shown, the electrical schematic diagram of the matching circuit can be first imported into the impedance matching tool, and the topological model can be decomposed to obtain the antenna matching network, the RF receiver input matching network and the RF receiver. Among them, the RF receiver can be a chip. According to the model of the RF receiver chip, its radio frequency mode and type (i.e., communication type) can be determined, including RFID, Bluetooth and UWB. According to the determined type, the key parameters such as the bandwidth and center frequency of the type are imported, and the initial impedance of the matching network is calculated based on the key parameters, and the target impedance with the minimum signal reflection and loss under the radio frequency mode is determined. The initial impedance and the target impedance are imported into the Smith chart model to obtain the circuit model generated by the Smith chart. The circuit model generated by the Smith chart can be called to generate the electrical schematic diagram of the cascade required to achieve the target impedance.

[0104] By adopting the technical solution provided in the embodiment of the present application, the PEPS function is integrated into the domain, which reduces the complexity and cost of the system and improves the reliability and coordination ability of the system. At the same time, the method reduces the reflection loss of the RF signal and improves the RF signal strength, which can ensure the experience of keyless entry and start, and achieves higher benefits at a lower cost.

[0105] All the above optional technical solutions can be arbitrarily combined to form optional embodiments of the present application, which will not be described one by one here.

[0106] The following is an embodiment of the device of the present application, which can be used to execute the embodiment of the method of the present application. For details not disclosed in the embodiment of the device of the present application, please refer to the embodiment of the method of the present application.

[0107] Fig.15 Schematic diagram of an impedance matching device provided in an embodiment of the present application. Fig.15 As shown, the device comprises:

[0108] The acquisition module 1501 is configured to acquire an electrical schematic diagram of the keyless entry and start system, and obtain an initial impedance matching circuit and a wireless receiver circuit module of the keyless entry system according to the electrical schematic diagram;

[0109] The determination module 1502 is configured to determine the communication parameters according to the communication mode of the wireless receiver circuit module, and determine the initial matching impedance and the target matching impedance of the initial impedance matching circuit according to the communication parameters;

[0110] A drawing module 1503 is configured to draw a Smith chart of the keyless entry and start system, and determine circuit update information from an initial matching impedance to a target matching impedance in the Smith chart;

[0111] The matching module 1504 is configured to modify the initial impedance matching circuit according to the circuit update information to obtain the impedance matching circuit of the keyless entry and start system.

[0112] According to the technical solution provided in the embodiment of the present application, the electrical schematic diagram of the PEPS system is decomposed into an initial impedance matching circuit and a wireless receiver circuit module, the communication parameters are determined based on the communication mode of the wireless receiver circuit module, and the initial matching impedance and the target matching impedance of the initial impedance matching circuit are determined according to the communication parameters, and then the circuit update information from the initial matching impedance to the target matching impedance is determined in the Smith chart of the PEPS system, and finally the initial impedance matching circuit is modified according to the circuit update information to obtain the impedance matching circuit of the PEPS system, thereby achieving more accurate impedance matching for the RF receiving module of the PEPS system, improving the RF signal reception and transmission sensitivity of the PEPS system, reducing the RF signal loss, reducing the probability of abnormal signal reception and transmission of the PEPS system, and improving the user experience.

[0113] In some implementations, the initial impedance matching circuit includes a first initial impedance matching circuit and a second initial impedance matching circuit; the first initial impedance matching circuit is used to match the equivalent impedance of the antenna of the keyless entry and start system, and the second initial impedance matching circuit is used to match the equivalent impedance of the wireless receiver circuit.

[0114] In some embodiments, the communication mode of the keyless entry and start system includes at least one of a radio frequency identification communication mode, a Bluetooth communication mode, and an ultra-high frequency communication mode, and the communication parameters include at least one of a bandwidth, a center frequency, a baud rate, and a frequency deviation; the method also includes: determining a matching mode according to the communication mode or the communication parameters, the matching modes including indirect matching and conjugate matching; in response to determining that the matching mode is an indirect match, determining a first target matching impedance of the initial impedance matching circuit according to the communication parameters; or in response to determining that the matching mode is a conjugate match, determining a second target matching impedance of the initial impedance matching circuit according to the communication parameters.

[0115] In some embodiments, determining a first target matching impedance of an initial impedance matching circuit based on communication parameters includes: determining a signal loss rate and a receiving sensitivity of a keyless entry and start system based on the communication parameters; determining a matching impedance corresponding to a target signal loss rate and receiving sensitivity combination as a first target matching impedance; wherein the target signal loss rate and receiving sensitivity combination includes a signal loss rate lower than a preset loss rate threshold and a receiving sensitivity higher than a preset sensitivity threshold.

[0116] In some embodiments, determining a second target matching impedance of an initial impedance matching circuit according to communication parameters includes: obtaining a communication frequency in the communication parameters; calculating a first initial equivalent impedance between an antenna of a keyless entry and start system and a first initial impedance matching circuit at the communication frequency; and determining a conjugate impedance of the first initial equivalent impedance as a second target matching impedance.

[0117] In some embodiments, determining the initial matching impedance of the initial impedance matching circuit according to the communication parameters includes: obtaining the communication frequency in the communication parameters; calculating the second initial equivalent impedance of the first initial matching circuit at the communication frequency, and the third initial equivalent impedance of the second initial matching circuit at the communication frequency; determining the second initial equivalent impedance and the third initial equivalent impedance as the initial matching impedance.

[0118] In some embodiments, determining circuit update information from an initial matching impedance to a target matching impedance in a Smith chart includes: determining a path from the initial matching impedance to the target matching impedance along an arc of at least one target circle in the Smith chart; determining the circuit update information based on an arc direction and an arc length included in the path; wherein the circuit update information includes at least one of the following: a type of component to be added, a connection method of the added component in the initial impedance matching circuit, a parameter value of the added component, and a parameter value after modifying the parameters of the existing component.

[0119] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0120] Fig.16 Schematic diagram of an electronic device provided in an embodiment of the present application. Fig.16 As shown, the electronic device 16 of this embodiment includes: a processor 1601, a memory 1602, and a computer program 1603 stored in the memory 1602 and executable on the processor 1601. When the processor 1601 executes the computer program 1603, the steps in the above-mentioned method embodiments are implemented. Alternatively, when the processor 1601 executes the computer program 1603, the functions of the modules / units in the above-mentioned device embodiments are implemented.

[0121] The electronic device 16 may be a desktop computer, a notebook, a PDA, a cloud server, or other electronic device. The electronic device 16 may include, but is not limited to, a processor 1601 and a memory 1602. Those skilled in the art will appreciate that Fig.16 The electronic device 16 is merely an example and does not limit the electronic device 16 , and may include more or less components than those shown in the figure, or different components.

[0122] Processor 1601 can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

[0123] The memory 1602 may be an internal storage unit of the electronic device 16, for example, a hard disk or memory of the electronic device 16. The memory 1602 may also be an external storage device of the electronic device 16, for example, a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card (FlashCard), etc. equipped on the electronic device 16. The memory 1602 may also include both an internal storage unit of the electronic device 16 and an external storage device. The memory 1602 is used to store computer programs and other programs and data required by the electronic device.

[0124] Those skilled in the art can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units.

[0125] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. The computer program may include computer program code, which may be in source code form, object code form, executable file or some intermediate form. Computer-readable media may include: any entity or device capable of carrying computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium, etc.

[0126] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. An impedance matching method, characterized in that: The method is used to determine an impedance matching circuit of a keyless entry start system, and the method comprises: Acquire an electrical schematic diagram of the keyless entry and start system, and obtain an initial impedance matching circuit and a wireless receiver circuit module of the keyless entry system according to the electrical schematic diagram; Determine a communication parameter according to a communication mode of the wireless receiver circuit module, and determine an initial matching impedance and a target matching impedance of the initial impedance matching circuit according to the communication parameter; Draw a Smith chart of the keyless entry start system, and determine circuit update information from the initial matching impedance to the target matching impedance in the Smith chart; The initial impedance matching circuit is modified according to the circuit update information to obtain the impedance matching circuit of the keyless entry and start system.

2. The method according to claim 1, characterized in that The initial impedance matching circuit includes a first initial impedance matching circuit and a second initial impedance matching circuit; The first initial impedance matching circuit is used to match the equivalent impedance of the antenna of the keyless entry and start system, and the second initial impedance matching circuit is used to match the equivalent impedance of the wireless receiver circuit.

3. The method according to claim 2, characterized in that The communication mode of the keyless entry and start system includes at least one of a radio frequency identification communication mode, a Bluetooth communication mode and an ultra-high frequency communication mode, and the communication parameter includes at least one of a bandwidth, a center frequency, a baud rate and a frequency deviation; The method further comprises: Determine a matching mode according to the communication mode or the communication parameter, wherein the matching mode includes indirect matching and conjugate matching; In response to determining that the matching mode is indirect matching, determining a first target matching impedance of the initial impedance matching circuit according to the communication parameter; or In response to determining that the matching mode is conjugate matching, a second target matching impedance of the initial impedance matching circuit is determined according to the communication parameter.

4. The method according to claim 3, characterized in that The determining, according to the communication parameter, a first target matching impedance of the initial impedance matching circuit comprises: determining a signal loss rate and a receiving sensitivity of the keyless entry and start system according to the communication parameters; Determine a matching impedance corresponding to a target signal loss rate and a receiving sensitivity combination as the first target matching impedance; The target signal loss rate and receiving sensitivity combination includes a signal loss rate lower than a preset loss rate threshold and a receiving sensitivity higher than a preset sensitivity threshold.

5. The method according to claim 3, characterized in that: The determining, according to the communication parameter, a second target matching impedance of the initial impedance matching circuit comprises: Acquire the communication frequency in the communication parameters; Calculating a first initial equivalent impedance between the antenna of the keyless entry and start system and the first initial impedance matching circuit at the communication frequency; A conjugate impedance of the first initial equivalent impedance is determined as the second target matching impedance.

6. The method according to claim 3, characterized in that The determining the initial matching impedance of the initial impedance matching circuit according to the communication parameter comprises: Acquire the communication frequency in the communication parameters; Calculating a second initial equivalent impedance of the first initial matching circuit at the communication frequency, and a third initial equivalent impedance of the second initial matching circuit at the communication frequency; The second initial equivalent impedance and the third initial equivalent impedance are determined as the initial matching impedances.

7. The method according to claim 1, characterized in that Determining circuit update information from the initial matching impedance to the target matching impedance in the Smith chart includes: Determine in the Smith chart a path from the initial matching impedance to the target matching impedance along an arc of at least one target circle; Determining the circuit update information according to the arc direction and arc length included in the path; The circuit update information includes at least one of the following: The types of components that need to be added, the connection method of the added components in the initial impedance matching circuit, the parameter values ​​of the added components, and the parameter values ​​of the modified parameters of the existing components.

8. An impedance matching device, characterized in that: include: An acquisition module is configured to acquire an electrical schematic diagram of a keyless entry and start system, and obtain an initial impedance matching circuit and a wireless receiver circuit module of the keyless entry system according to the electrical schematic diagram; a determination module configured to determine a communication parameter according to a communication mode of the wireless receiver circuit module, and determine an initial matching impedance and a target matching impedance of the initial impedance matching circuit according to the communication parameter; A drawing module, configured to draw a Smith chart of the keyless entry and start system, and determine circuit update information from the initial matching impedance to the target matching impedance in the Smith chart; The matching module is configured to modify the initial impedance matching circuit according to the circuit update information to obtain the impedance matching circuit of the keyless entry and start system.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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