Programmable low frequency carrier radio frequency signal cooperative control method, circuit and generating system

Abstract

The present application relates to the technical field of automobile electric control system testing, in particular to a programmable low-frequency carrier radio frequency signal cooperative control method, circuit and generating system. The method comprises the following steps: input voltage is connected through an external power supply interface, converted into 5V stable working voltage by a voltage stabilizing chip, and after parallel multi-stage filtering capacitor filters out power supply noise, power is supplied to the MCU control module and each functional module. The present application effectively solves the technical problems of multi-signal accurate generation and reliable interaction in complex test scenarios by constructing an integrated programmable signal cooperative control architecture. Specifically, the cooperative control method ensures that the MCU and signal output module obtain a pure 5V power supply with a ripple less than 50mV through multi-stage filtering design and independent power supply strategy of the power supply module, suppresses noise coupling from the power supply end, and improves the stability of signal generation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automobile electric control system testing, in particular to a programmable low-frequency carrier radio frequency signal cooperative control method, circuit and generating system. BACKGROUND

[0002] Precise simulation of low-frequency carrier signals and vehicle body collision signals is a technical link for verifying the reliability of vehicle-mounted sensors and communication modules. Existing signal generating devices usually use fixed hardware architecture to realize single signal output, or generate multiple signals through discrete module combination, but there are the following technical bottlenecks: on the one hand, the cooperative control of low-frequency carrier signals and collision signals relies on external complex timing circuits, the programmable configuration capability of signal frequency, pulse width and timing is limited, and it is difficult to adapt to the diversified testing needs of different vehicle sensors; on the other hand, the interaction interface between the signal output module and the upper computer lacks effective signal conditioning protection mechanism, is easy to be misjudged by external electromagnetic interference, and the state feedback is only realized through a single indicator light or upper computer software, which cannot quickly identify the working mode in the field operation. In addition, the filter design of the power module is insufficient, and high-frequency noise is easy to couple to the signal generation circuit, causing distortion of the output signal and affecting the accuracy of the test results. Therefore, how to realize multi-signal programmable cooperative control, high-reliability human-computer interaction and low-noise power supply in a compact circuit architecture has become a technical problem restricting the performance improvement of vehicle signal simulation equipment. SUMMARY

[0003] The present disclosure provides a programmable low-frequency carrier radio frequency signal cooperative control method, circuit and generating system, which aims to overcome at least one of the deficiencies in the prior art.

[0004] To achieve the above-mentioned purpose, the technical solutions disclosed by the present application are as follows:

[0005] According to one aspect of the present disclosure, a programmable low-frequency carrier radio frequency signal cooperative control method is provided, comprising the following steps:

[0006] An input voltage is connected through an external power supply interface, converted into a 5V stable working voltage by a voltage stabilizing chip, and after filtering out power supply noise by parallel connection of multiple filter capacitors, it is used to power the MCU control module and each functional module;

[0007] Two kinds of signals are generated by using the MCU control module: one is a low-frequency carrier signal generated according to the preset frequency and timing, which is driven by a two-stage transistor amplification circuit and output to an external device through an output interface; the other is a specified PWM signal generated according to the characteristic parameters of the vehicle body collision signal, which is output through an independent interface after a transistor drive circuit and used to simulate the collision condition;

[0008] The external trigger input signal is received by the host computer communication module, and is transmitted to the MCU control module after current limiting, clamping and filtering processing by the signal conditioning circuit, for the external device to control the working mode of the circuit and configure parameters.

[0009] The MCU control module drives the double-color indicator light according to the current working state: the red indicator light is lit when the output PWM collision signal is output, and the green indicator light is lit when the normal low-frequency carrier signal is output, for quick identification of the working mode.

[0010] Further, the external power supply is connected through the connector, the voltage conversion is realized through the voltage stabilizing chip, the input end is connected in parallel with the high-frequency filtering capacitor to suppress surge interference, and the output end is connected in parallel with multiple groups of capacitors with different capacitance values to form a π-type filter circuit, and the output voltage ripple is less than 50mV.

[0011] The stabilized 5V power supply directly supplies power to the MCU chip, and supplies power to the signal amplification circuit and the indication module through independent power lines, so as to avoid power noise coupling between different modules.

[0012] Further, the frequency, pulse width and output timing of the low-frequency carrier signal are configured by the internal timer of the MCU control module, a square wave signal with a frequency of 10KHz and a pulse width of 100ms is output, the driving capability is improved through the Darlington amplifier circuit composed of two-stage NPN transistors, the output end is connected in series with a matching resistor and in parallel with an RC filter circuit, for suppressing high-frequency harmonics and realizing 50Ω impedance matching.

[0013] The duty cycle and period parameters of the PWM collision signal can be configured by the host computer software, a pulse signal with a duty cycle of 50% and a frequency of 2Hz is generated, and the signal is output through the transistor common-emitter amplifier circuit to meet the signal simulation requirements of the automobile electronic collision sensor.

[0014] Further, the interface of the host computer adopts a single-ended signal input method, the input signal is processed by the protection circuit composed of a current limiting resistor, a voltage stabilizing diode and a filtering capacitor, the voltage amplitude is clamped to a safe range of 3.3V, and the high-frequency noise is filtered out and connected to the communication pin of the MCU.

[0015] The communication protocol adopts UART serial communication, supports adjustable baud rate from 9600 to 115200, so as to realize remote configuration and real-time monitoring of the signal output mode, frequency parameters and indicator light state by the external host computer.

[0016] According to another aspect of the present disclosure, a programmable low-frequency carrier radio frequency signal cooperative control circuit is provided for performing the programmable low-frequency carrier radio frequency signal cooperative control method as described above, comprising:

[0017] A power module is configured to provide a stable working voltage.

[0018] MCU control module, comprising MCU chip U9, for generating low-frequency carrier signal, PWM collision signal and controlling state indication;

[0019] Host computer communication module, for realizing signal interaction with external host computer;

[0020] Low-frequency carrier signal output module, for outputting low-frequency carrier signal with fixed frequency and timing;

[0021] Collision signal simulation module, for outputting specified PWM signal to simulate vehicle body collision signal;

[0022] State indication module, for displaying circuit working state through indicator light;

[0023] The power module is electrically connected with the MCU control module, and the host computer communication module, the low-frequency carrier signal output module, the collision signal simulation module and the state indication module are respectively electrically connected with the MCU control module.

[0024] Further, the power module comprises:

[0025] Connector J3, for connecting external power supply VCC;

[0026] Connector J4, ground GND;

[0027] Voltage stabilizing chip U2, input end IN connected with the connector J3, output end OUT outputting 5V voltage stabilizing power supply;

[0028] Capacitor CB6 and capacitor CB7 are connected in parallel between the connector J3 and the connector J4;

[0029] Capacitor CB8, capacitor CB9 and capacitor C5 are connected in parallel between the output end OUT of the voltage stabilizing chip U2 and the connector J4;

[0030] The output end OUT of the voltage stabilizing chip U2 is electrically connected with the 9th pin of the MCU chip U9.

[0031] Further, the host computer communication module comprises:

[0032] Host computer interface J2, connected with the 11th pin of the MCU chip U9 through resistor R6;

[0033] Resistor R2, diode D1 and capacitor C3 are connected in parallel between the 11th pin of the MCU chip U9 and the ground;

[0034] Capacitor C2 is connected in parallel between the host computer interface J2 and the ground;

[0035] The host computer interface J2 is used to receive the trigger input signal of the external host computer and transmit to the MCU chip U9.

[0036] Further, the low-frequency carrier signal output module comprises:

[0037] The resistance R4 and the resistance R7 are connected in series, with one end grounded and the other end connected to the 12th pin (SDW_CLK) of the MCU chip U9;

[0038] The transistor Q2 has its gate connected between the resistance R4 and the resistance R7, its emitter grounded, and its collector connected to a 5V voltage stabilizer through the resistance R1 and the resistance R3;

[0039] The transistor Q1 has its gate connected between the resistance R1 and the resistance R3, its emitter connected to a 5V voltage stabilizer, and its collector connected to the connector J1 through the resistance R5;

[0040] The resistance R8 and the capacitor C1 are connected in parallel between the collector of the transistor Q1 and the ground;

[0041] The resistance R9 is connected between the connector J1 and the ground;

[0042] The connector J1 is used to output the low-frequency carrier signal generated by the MCU chip U9.

[0043] Further, in the collision signal simulation module, the resistance R10 and the resistance R11 are connected in series, with one end grounded and the other end connected to the 14th pin of the MCU chip U9, and the gate of the transistor Q3 is connected between the resistance R10 and the resistance R11, with the emitter grounded and the collector connected to the connector J5, which is used to output the PWM collision signal;

[0044] In the state indication module, the 19th pin (LED_R) of the MCU chip U9 is connected to a red indicator light, and the 20th pin (LED_G) is connected to a green light, which is then connected to a 5V voltage stabilizer through the resistance R15;

[0045] The red indicator light is used to indicate the collision signal output state, and the green light is used to indicate the normal signal output state.

[0046] According to another aspect of the present disclosure, a programmable low-frequency carrier radio frequency signal generation system is provided, which is integrated with the programmable low-frequency carrier radio frequency signal cooperative control circuit as described above, and comprises:

[0047] The control unit comprises an MCU chip U9, which is used to execute signal generation algorithms, analyze host computer instructions and control state indications, and configure parameters and control timing of low-frequency carrier signals and PWM collision signals;

[0048] The power supply unit comprises a power supply module, is used for converting an external input power supply into a 5V stable voltage, suppressing power supply noise through a multi-stage filtering circuit, and providing pure power supply;

[0049] The signal generation unit comprises a low-frequency carrier signal output module and a collision signal simulation module, and is respectively used for generating a low-frequency carrier signal with a fixed frequency time sequence and a PWM collision signal with configurable parameters to meet the signal output requirements of different test scenarios.

[0050] The man-machine interaction unit comprises an upper computer communication module and a state indication module, realizes the input of control instructions of external equipment through an upper computer interface, and realizes the visual feedback of the working state through a double-color indication lamp.

[0051] The beneficial effects of the present application are:

[0052] The present application effectively solves the technical problems of accurate generation and reliable interaction of multiple signals in complex test scenarios by constructing an integrated programmable signal cooperative control architecture.

[0053] Further, the MCU control module dynamically configures the frequency, pulse width and time sequence of the low-frequency carrier signal based on the internal timer, and realizes low-distortion output of the 10KHz square wave signal through the Darlington amplification circuit and the RC matching network, while supporting remote configuration of the duty cycle and period of the PWM collision signal by the upper computer, meeting the high-precision simulation requirements of the automobile electronic collision sensor.

[0054] Further, the current limiting, clamping and filtering protection circuit of the upper computer communication module stabilizes the input signal amplitude in the 3.3V safe range, cooperates with the adjustable baud rate communication of the UART protocol, realizes the anti-interference transmission of the control instructions and the real-time configuration of the parameters.

[0055] The present application realizes the programmability of signal generation, the reliability of interaction interface and the intuitiveness of state feedback in a single circuit system through the cooperative optimization of hardware circuit and control method, and provides a high-precision and high-adaptability signal simulation solution for the automatic test of vehicle-mounted electronic equipment.

[0056] The above description is only a summary of the technical solutions of the present application, in order to more clearly understand the technical means of the present application, and can be implemented according to the content of the specification, the following will be described in detail with the preferred embodiments of the present application and the accompanying drawings. Attached Figure Description

[0057] Figure 1 This is a flowchart of the programmable low-frequency carrier radio frequency signal cooperative control method of the present invention;

[0058] Figure 2 This is a circuit diagram of the programmable low-frequency carrier radio frequency signal coordinated control circuit of the present invention. Detailed Implementation

[0059] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0060] In embodiments of the present invention, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" or "for example" in embodiments of the present invention should not be construed as being more preferred or advantageous than other embodiments or designs. Rather, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0061] The present invention provides the following preferred embodiments:

[0062] Example 1: To address the issues of insufficient collaborative control precision, poor external interaction reliability, and low efficiency in identifying working status in existing vehicle signal simulation equipment when outputting multi-mode signals, this example provides a programmable low-frequency carrier radio frequency signal collaborative control method. Through the collaborative configuration of power link noise suppression design, dual signal independent generation architecture, anti-interference communication interface, and visual status feedback mechanism, it achieves precise control of low-frequency carrier signals and collision simulation signals in automotive electronic testing scenarios.

[0063] like Figure 1 As shown, the flow of the collaborative control method is as follows:

[0064] S100: Input voltage is received through an external power interface, converted into a stable 5V operating voltage by a voltage regulator chip, and then filtered by multiple parallel filter capacitors to remove power supply noise before supplying power to the MCU control module and various functional modules.

[0065] S200: Generates two types of signals using the MCU control module:

[0066] S201: Generates a low-frequency carrier signal according to a preset frequency and timing, drives the signal through a two-stage transistor amplifier circuit, and outputs it to an external device through the output interface;

[0067] S202: Generates a specified PWM signal based on the characteristic parameters of the vehicle collision signal, and outputs it through an independent interface after passing through a transistor drive circuit, for simulating collision conditions.

[0068] S300: Receive external trigger input signal through host computer communication module, transmit to MCU control module after current limiting, clamping and filtering processing by signal conditioning circuit, for external device to control the working mode of the circuit and parameter configuration.

[0069] S400: MCU control module drives double-color indicator light according to current working state: when outputting PWM collision signal, red indicator light is lit, when outputting normal low-frequency carrier signal, green indicator light is lit, for quick identification of working mode.

[0070] In implementation, first, a stable power supply system is constructed: external input voltage is connected through a special power supply interface, which adopts anti-reverse connection design to improve circuit safety, and the voltage after connection is first converted by a voltage stabilizing chip to stabilize the fluctuating input voltage to 5V working voltage. Considering the interference of power supply noise on high-frequency signal generation, multiple-stage filtering capacitors are connected in parallel at the input and output sides of the voltage stabilizing chip, forming a high-frequency noise attenuation path. The input side capacitor is used to suppress the surge interference introduced by the external power supply, and the output side capacitor is connected to form a composite filter network through the combination of capacitors with excellent high-frequency characteristics and electrolytic capacitors with significant low-frequency filtering effect, effectively filtering the power supply ripple. The stable voltage after this processing is supplied to the MCU control module and each functional module through independent power lines, avoiding power noise coupling between power modules and signal processing modules, and providing a pure energy basis for subsequent signal generation.

[0071] Further, in the signal generation link, the MCU control module as the core processing unit, based on the internal high-precision timer resources, realizes the time-sharing or parallel generation of two different characteristic signals through software programming. For the low-frequency carrier signal, according to the preset frequency and timing parameters, the MCU outputs the initial pulse signal, which is first amplified by two-stage transistor amplification circuit to improve the driving capability. The first transistor realizes small signal amplification, and the second transistor further improves the current driving capability to ensure that the signal can effectively drive the external load. The amplified signal is transmitted to the external device through a special output interface, which adopts impedance matching design to reduce reflection loss in the signal transmission process. For collision condition simulation requirements, the MCU generates a specific PWM signal according to the typical characteristic parameters of the vehicle body collision signal such as pulse width and repetition frequency. Unlike the processing path of the low-frequency carrier signal, the PWM signal is amplified by an independent transistor drive circuit and output by an independent interface to avoid crosstalk between the two signals during transmission. This dual-signal independent generation and output architecture ensures the isolation of the two signals in frequency characteristics, driving method and transmission path, meeting the high-precision simulation requirements of different signal types in automotive electronic testing.

[0072] Further, the host computer communication module serves as the input channel for external control instructions, and its reliability directly affects the programmable ability of the entire system. After the external trigger input signal enters the circuit through the communication interface, it is first preprocessed by the signal conditioning circuit. The current-limiting resistor is used to suppress the impact of abnormally large current on the subsequent circuit, the voltage stabilizing diode clamps the signal amplitude within the safe voltage range acceptable by the MCU, and the filter capacitor filters out high-frequency noise, forming a three-level protection mechanism to ensure the integrity and safety of the input signal. The conditioned signal is transmitted to the MCU control module, supporting remote control of the circuit operating mode (such as signal output type switching) and parameter configuration (such as signal frequency and pulse width adjustment) by external devices. The communication protocol uses the universal serial communication standard, supporting adaptive adjustment of the baud rate to accommodate different models of host computer devices and enable reliable interaction of control instructions.

[0073] Further, to improve the convenience of on-site operation, the status indication module uses a dual-color indicator light design, which is driven by the MCU control module in real time based on the current operating state. When the system outputs a PWM collision signal, the MCU sends a high-level signal to the red indicator light driving circuit, lighting up the red indicator light and indicating that the current operating mode is the collision condition simulation mode. When a normal low-frequency carrier signal is output, the green indicator light is activated, indicating that the system is in the normal signal output mode. The two indicator lights use independent driving circuits to avoid mutual interference, and the brightness and response speed of the indicator lights are optimized to ensure clear identification under different lighting conditions. This visual status feedback mechanism allows the operator to quickly determine the system operating state through intuitive light indicators without relying on the host computer software interface, improving test efficiency.

[0074] Further, the multi-stage filtering design and independent power supply strategy of the power module cut off the noise propagation path at the hardware level, ensuring that the MCU and signal processing circuit operate in a stable power supply environment. The separation of the dual-signal generation paths avoids mutual interference between signals through dedicated amplification circuits and independent output interfaces, ensuring the waveform quality of the output signals. The signal conditioning circuit of the host computer communication module effectively enhances the system's anti-interference ability to external electromagnetic interference, ensuring accurate analysis of control instructions. The dynamic driving mechanism of the dual-color indicator light establishes a simple and efficient human-machine interface, realizing real-time mapping of the operating mode. The organic combination of electrical connections and logical control of various functional modules forms a complete cooperative control system, meeting the stringent requirements of automotive electronic testing for signal accuracy, and improving the convenience and reliability of device operation.

[0075] It needs to be understood that the specific model and parameters of the hardware components such as the external power supply interface, the voltage stabilizing chip, the transistor amplification circuit, and the indicator lamp driving circuit in the embodiment can be adjusted adaptively according to the actual application scene. The embodiment is to realize programmable cooperative control of the low-frequency carrier signal and the collision simulation signal through the control logic and circuit architecture constructed by the above method. Through the power supply stability guarantee, signal generation independence design, communication interface protection regulation, and state indication visualization technical scheme, the embodiment provides a standardized signal control solution for the vehicle-mounted electronic test equipment, effectively solving the cooperative control problem of multiple signal outputs.

[0076] Embodiment two: To solve the problem of signal distortion caused by power supply noise coupling in the existing vehicle-mounted signal simulation equipment, the power supply system is optimized in this embodiment. Through the connector physical interface specification, multi-stage filter network construction, and independent power supply strategy, the noise suppression of the power supply link is realized, and stable and pure working voltage is provided for the core circuit.

[0077] During implementation, the external power supply is connected to the circuit through a dedicated power supply connector. The connector adopts a mechanical locking structure to ensure the stability of the electrical connection, and its input end is directly connected to the input pin of the voltage stabilizing chip. The voltage stabilizing chip is selected as a low dropout LDO type, which has a high power supply rejection ratio PSRR characteristic and can convert the input voltage to a 5V direct current output. A high-frequency characteristic porcelain capacitor is connected in parallel at the input end of the voltage stabilizing chip to suppress the surge voltage and high-frequency noise introduced by the external power supply, forming the first-stage filter protection. The output end adopts a π-type filter circuit constructed by multiple capacitors with different capacitance values in parallel, including an electrolytic capacitor for filtering low-frequency ripple, a high-frequency porcelain capacitor for absorbing switching noise, and a tantalum capacitor for improving transient response capability. Through the gradient configuration of the capacitance values, full-band noise attenuation is achieved, and the output voltage ripple is finally controlled within 50mV.

[0078] Further, the stabilized 5V power supply is supplied to the MCU chip, the signal amplification circuit, and the indication module through independent power supply lines. The power supply line of the MCU chip adopts a single-point grounding design, and the power supply line width is widened to reduce the line impedance, ensuring the stability of the power supply of the digital core unit. The power supply line of the signal amplification circuit is physically separated from the MCU power supply line to avoid noise interference on the MCU caused by current fluctuations during the operation of the amplification circuit. The power supply line of the indication module is connected in series with a small resistance resistor to limit the working current of the indicator lamp and reduce its impact on the main power supply. This shunt power supply architecture realizes power isolation of different functional modules at the physical level through circuit board layout optimization, effectively avoiding noise coupling between the power module and the signal processing module.

[0079] Further, the ground pin of the power connector is directly connected with the ground plane of the circuit board, forming a low-impedance return path to reduce the ground loop noise. The heat dissipation pad of the voltage stabilizing chip is connected with the ground layer through the via hole, ensuring the effective dissipation of heat during the operation of the chip and avoiding the output voltage fluctuation caused by temperature drift. It should be understood that the selection of the filter capacitor needs to be adjusted according to the actual noise characteristics of the input power supply. For example, when there is serious electromagnetic interference in the external power supply, a common-mode inductor can be added at the input end to form an LC filter network with the filter capacitor, enhancing the suppression ability of common-mode noise.

[0080] During the circuit debugging process, the ripple voltage at the output end of the power supply is measured by an oscilloscope to verify the effectiveness of the π-type filter circuit. The measurement results show that the voltage waveform after multi-stage filtering is smooth, and the high-frequency burr is significantly suppressed, meeting the requirements of high-precision signal generation for power supply stability. At the same time, the impedance matching design of the independent power supply circuit ensures the voltage stability of each module under dynamic load changes. When the signal amplification circuit enters a high drive state, the voltage fluctuation at the MCU power supply end is controlled within ±1%, avoiding the signal timing deviation caused by power supply fluctuation.

[0081] The benefits of this embodiment are that through the standardized design of the power connector, the parameter optimization of the multi-stage filter network, and the engineering implementation of the independent power supply strategy, a low-noise power supply system architecture is constructed. This architecture not only provides a stable working environment for the MCU control module, but also cuts off the noise propagation path from the power supply end to the signal generation circuit, laying a foundation for the high-precision output of low-frequency carrier signals and collision simulation signals.

[0082] Embodiment Three: To solve the problems of insufficient signal generation precision and poor adaptability in existing equipment, this embodiment optimizes the generation path of low-frequency carrier signals and PWM collision signals. Through MCU timer resource scheduling, dedicated amplification circuit design, and impedance matching technology, programmable precise output of the two signals is achieved.

[0083] In the low-frequency carrier signal generation link, the MCU control module calls the internal high-precision timer to realize the digital setting of signal frequency, pulse width and timing through register configuration. Taking a 10KHz frequency, 100ms pulse width square wave signal as an example, the timer works in the up-counting mode, and when the count value reaches the period register setting value (50μs), it triggers the flip to generate a 50% duty cycle basic square wave. The signal is first input into a Darlington amplifier circuit composed of two-stage NPN transistors, the first-stage transistor works in the common-emitter state to realize voltage amplification; the base of the second-stage transistor is connected to the collector of the first-stage transistor to form a current amplification cascade, and the overall amplification factor can reach hFE1xhFE2, which improves the driving capability of the signal and meets the needs of driving long-distance transmission cables or high-input-impedance loads. The amplified signal is connected in series with a matching resistor at the output end, and an RC filter circuit is connected in parallel, where the resistor is used to match the output impedance with the load impedance to reduce signal reflection; the capacitor filters out high-frequency harmonics to ensure that the rising and falling edges of the output waveform meet the time-domain characteristics of the square wave signal.

[0084] For the PWM collision signal, its duty cycle and period parameters can be remotely configured by the host computer software. After receiving the configuration instructions, the MCU adjusts the comparison register value of the timer to generate a PWM signal with corresponding parameters. Taking a typical 50% duty cycle, 2Hz frequency signal as an example, the timer period is set to 500ms, and the comparison register value is set to 250ms, and the pulse is generated by flipping the output pin level. The signal is processed by a transistor common-emitter amplifier circuit, a current-limiting resistor is connected in series at the base to protect the MCU pin, the collector is connected to a pull-up resistor to the 5V power supply, and the emitter is connected to ground, forming a typical signal amplification structure. The 3.3V level signal output by the MCU is converted into a 5V amplitude driving signal, which meets the input level requirements of the automotive electronic collision sensor. The amplified signal is transmitted through an independent output interface, which maintains a distance from the low-frequency carrier signal interface in physical layout to reduce signal crosstalk.

[0085] Further, the bias resistor of the Darlington amplifier circuit uses a precision surface mount resistor to ensure that the transistor works in the linear amplification zone and avoid saturation distortion. The parameters of the RC filter circuit are designed according to the bandwidth of the target signal, for example, for a 10KHz fundamental signal, the capacitance value needs to be selected to ensure that the cutoff frequency is much higher than 20KHz to retain the fundamental component and attenuate high-order harmonics. It should be understood that the clock source of the internal timer of the MCU can be selected from an external crystal oscillator or an internal RC oscillator, the former provides higher frequency accuracy and is suitable for test scenarios with strict frequency stability requirements; the latter has low cost advantage and is suitable for applications with moderate accuracy requirements.

[0086] In hardware implementation, the PCB layout of the signal generation circuit follows the high-speed signal design principle: the wiring from the MCU output pin to the amplifier circuit is as short and straight as possible to reduce parasitic capacitance; the power supply pin of the amplifier circuit is configured with a decoupling capacitor nearby to suppress the modulation effect of power supply noise on the signal; the output interface uses a standardized connector, such as a BNC interface, to ensure consistency of impedance matching. During debugging, the output signal is detected by a spectrum analyzer to detect the harmonic components, and the effectiveness of the RC filter circuit is verified. The actual measurement results show that the amplitude of the third harmonic is reduced by more than 20 dB compared to the unfiltered state, meeting the requirements of vehicle-mounted electronic testing for signal purity.

[0087] This embodiment constructs a high-precision double-signal generation architecture through fine control of the MCU timer, selection design of the special amplifier circuit, and matching filter processing at the output end. This architecture not only supports fixed parameter output of low-frequency carrier signals, but also allows flexible configuration of PWM collision signals, and can adapt to diversified testing needs of sensors of different vehicle models. Circuit designers can adjust the timer parameters, amplifier circuit types, and filter network parameters according to actual testing scenarios, strike a balance between signal precision, driving capability, and power consumption, and provide a standardized signal input scheme for reliability verification of vehicle-mounted electronic control systems.

[0088] Embodiment Four: To solve the problems of existing equipment that the host computer communication is susceptible to electromagnetic interference and the parameter configuration flexibility is insufficient, this embodiment designs anti-interference and optimizes protocol adaptation for the communication interface. Through a three-stage signal conditioning circuit, a variable baud rate communication protocol, and electrical isolation measures, reliable transmission and real-time interaction of control commands are realized.

[0089] Further, the host computer interface uses a single-ended signal input method. After the external control signal is connected to the circuit through a dedicated connector, it first passes through a protection circuit composed of a current-limiting resistor, a voltage stabilizing diode, and a filter capacitor. The current-limiting resistor is connected in series in the signal input path to limit the input current in abnormal conditions and prevent overcurrent damage to the MCU pin. The voltage stabilizing diode is connected in parallel between the signal pin and the ground to clamp the input voltage amplitude within the safe range that the MCU can withstand, i.e., 3.3V±0.3V, to prevent external high-voltage signal impact. The filter capacitor is connected in parallel between the signal pin and the ground to form a low-pass filter, filter out high-frequency noise such as 10MHz or above interference signals, and ensure the integrity of the input signal. After the three-stage processing, the signal is connected to the UART communication pin of the MCU to realize level conversion and noise filtering of the control command.

[0090] Further, the communication protocol adopts the UART serial communication standard, supports adjustable baud rate in the range of 9600 to 115200, and realizes adaptive matching by software configuration of the baud rate register of the MCU. The control instruction sent by the upper computer contains a signal output mode (low frequency carrier / PWM collision), frequency parameters, indicator light state and other data frames. The data frame format follows a self-defined protocol, including start bit, data bit, check bit and stop bit. The check bit uses XOR check or CRC check to improve the accuracy of data transmission. After receiving the instruction, the MCU first verifies the check bit. If the data is correct, the instruction content is parsed, the signal generation parameters or indicator light state are updated, and a status feedback frame is sent through the reverse UART channel to realize two-way real-time communication.

[0091] Further, to enhance the anti-interference capability, the communication line is isolated from the power line during PCB layout, and the ground wire is used to reduce electromagnetic coupling. The connector shell is connected to the ground layer of the circuit board to form a shielding structure to suppress external radiation interference. For applications in strong electromagnetic environments, a high-speed optocoupler isolator can be added between the communication interface and the MCU to achieve electrical isolation and cut off the ground loop noise. However, this embodiment is based on a non-isolated design, and the protection circuit composed of passive elements meets the anti-interference requirements of general vehicle test environments. It should be understood that the value of the filter capacitor needs to be adjusted according to the target noise frequency. For example, in a high-frequency interference environment, multiple capacitors with different values, such as 1nF and 100nF, can be connected in parallel to widen the filter frequency band.

[0092] Further, in the software implementation layer, the UART communication module uses an interrupt-driven mode to ensure timely response to the host computer instructions in a low-power state. The baud rate adaptive function is realized by sending a specific handshake signal. The host computer first sends a fixed format baud rate detection frame. After receiving the signal, the MCU automatically identifies the baud rate by measuring the width of the start bit, avoiding the complexity of manual configuration. During communication, if the verification fails for three consecutive times, the retransmission mechanism is triggered to ensure reliable reception of critical instructions.

[0093] This embodiment cooperatively designs hardware protection circuit and software communication protocol to build a high-reliability human-computer interaction interface. This interface can effectively resist external electromagnetic interference and ensure accurate analysis of control instructions, while supporting flexible parameter configuration and state feedback to meet the needs of remote control of automatic test equipment.

[0094] Embodiment five: To solve the problems of low module coordination control efficiency and redundant hardware architecture in existing vehicle signal simulation circuits, this embodiment provides a programmable low-frequency carrier RF signal coordination control circuit. Through modular design and electrical connection optimization, the reliability and flexibility of signal generation, transmission and state feedback are ensured.

[0095] Specifically, the overall architecture of the circuit includes a power module, an MCU control module, an upper computer communication module, a low-frequency carrier signal output module, a collision signal simulation module, and a state indication module. Each module is electrically interconnected through a printed circuit board (PCB) to form a hierarchical hardware system. The power module serves as an energy supply unit, which is connected to an external input voltage through a dedicated power interface, and the voltage level is converted by a voltage stabilizing chip U2. The input end is connected in parallel with a high-frequency filter capacitor to suppress surge interference, and the output end is connected to a π-type filter network composed of multiple capacitors with different capacitance values to provide a 5V stable voltage with a ripple less than 50mV for the subsequent modules. The power module supplies power to the MCU control module and each functional module through independent wiring. The power supply pin of the MCU chip U9 is directly connected to the high-precision output end of the power module to ensure the stability of the power supply of the digital core unit.

[0096] Further, the MCU control module is the core of the circuit, and the high-precision timer resources integrated inside provide timing reference for signal generation. For the low-frequency carrier signal, the general timer (TIMx) of U9 generates an initial pulse signal through register configuration, which is output to the low-frequency carrier signal output module through the GPIO pin. For the PWM collision signal, the advanced control timer (TIM1) of U9 supports complementary output and dead zone control, and dynamically adjusts the duty cycle and period parameters according to the instructions from the upper computer. It should be understood that the reset circuit and crystal oscillator circuit of the MCU chip U9 are designed as follows: the reset pin is connected to an RC reset circuit to ensure reliable initialization, and an external 8MHz crystal oscillator is used in combination with an internal phase-locked loop (PLL) to provide a 72MHz system clock to meet the high-precision timing control requirements.

[0097] Further, the upper computer communication module realizes bidirectional transmission of external control instructions. The input interface is designed as a single-ended signal, and the external signal is processed by a three-stage protection circuit composed of a current limiting resistor R1, a voltage stabilizing diode D1, and a filter capacitor C1, and then connected to the UART communication pin of the MCU. The protection circuit clamps the input voltage to the safe range of 3.3V and filters out high-frequency noise to ensure the integrity of the control instructions. The communication protocol uses the UART serial standard, which supports adaptive adjustment of the baud rate. The MCU realizes signal output mode switching, parameter configuration, and state feedback by analyzing the data frame. For example, after receiving the mode switching instruction, U9 sends a control signal to the state indication module to change the level state of the indicator light driving circuit.

[0098] Further, the low-frequency carrier signal output module and the collision signal simulation module are taken as execution units, and independent signal paths are adopted to avoid crosstalk. The former receives a 10KHz square wave signal output by the MCU, and the driving capability is improved through a Darlington amplifier circuit composed of two NPN transistors Q1 and Q2. The output end is connected in series with a matching resistor R2 and connected in parallel with an RC filter circuit resistor R3 and a capacitor C2, so as to realize 50Ω impedance matching and high-frequency harmonic suppression. The latter converts a 3.3V level into a 5V driving signal through a common-emitter amplifier circuit of a transistor Q3 according to a PWM signal generated by the MCU, and transmits the signal to the collision sensor test end through an independent output interface. The power supply of the amplification circuit of the two signals is taken from the independent power supply circuit of the power supply module, so as to reduce the influence of power fluctuation on the MCU.

[0099] Further, the state indication module adopts a double-color LED with an independent drive circuit design. The red LED corresponds to the collision signal output mode, and the green LED corresponds to the low-frequency carrier signal output mode. The GPIO pin of the MCU controls the base current of the two indicator lights through a current-limiting resistor. When the PWM collision signal is output, the U9 sends a high level to the red LED drive circuit, so that the red light is turned on and emits light. When the low-frequency carrier signal is output, the green LED drive circuit is activated, and the green light emits light to indicate. The PCB layout of the indicator light is located at the edge of the circuit board, which is convenient for the operator to intuitively identify. The pull-up resistor value of the drive circuit ensures the uniform brightness of the indicator light, and avoids identification errors in strong light environment.

[0100] Further, the circuit board layout follows the electromagnetic compatibility (EMC) design principle: the power supply module and the power amplifier circuit are distributed at the edge of the circuit board, away from the high-frequency digital circuit of the MCU control module; analog and digital signals are routed in separate areas, and different functional areas are isolated by grounding copper foil; the output interface adopts a shielded connector, the shell of which is welded with the ground layer of the circuit board to form a complete shielding loop. It should be understood that the interconnection signal lines between the modules adopt a differential pair design to reduce common-mode noise interference. At the same time, the length of the key signal line is controlled within a reasonable range to avoid time sequence deviation caused by transmission delay.

[0101] Further, in the hardware implementation, the key element parameters of each module can be adjusted according to actual needs, for example, the voltage stabilizing chip can be replaced with a model with higher PSRR to adapt to harsh power supply environment, the transistor selection of the amplifier circuit needs to consider both gain and power consumption, and the current feedback resistor of the indicator light drive circuit can be increased to improve stability. During the debugging process, the key node signals of each module are monitored through an oscilloscope to verify the signal generation accuracy, transmission integrity and state indication response speed, so as to ensure the stable operation of the circuit within the rated working range.

[0102] The embodiment divides the function units such as power supply, signal processing, instruction interaction, signal output and state feedback by modular hardware architecture design. Each module has independent working ability and realizes collaborative linkage through the MCU control module. The hierarchical design not only reduces the circuit complexity, but also is convenient for later maintenance and function expansion, and provides a standardized hardware platform for the vehicle-mounted electronic test equipment.

[0103] Embodiment six: in order to solve the problem that the power module power supply stability is insufficient to cause the rear-end circuit to work abnormally, the embodiment further refines the hardware architecture of the power module, and constructs a reliable power conversion and filtering network by the connection relationship and function configuration of each element.

[0104] As shown in Figure 2 The power module takes the connector J3 and the connector J4 as the external power supply access interface, wherein the connector J3 is used for accessing the external power supply VCC, and the connector J4 realizes grounding GND, and the two constitute the electrical circuit of the power input. The input end IN of the voltage stabilizing chip U2 is directly connected with the connector J3, and the function is to convert the external input voltage into stable 5V direct current output, and a plurality of groups of filtering capacitors are connected in parallel between the output end OUT and the connector J4. Specifically, the capacitor CB6 and the capacitor CB7 are connected in parallel between the connector J3 and the connector J4, forming an input stage high-frequency noise suppression network, which can absorb the surge voltage and high-frequency interference introduced by the external power supply; the capacitor CB8, the capacitor CB9 and the capacitor C5 are connected in parallel between the output end OUT of the voltage stabilizing chip U2 and the connector J4, and the combination of different capacitance capacitors realizes full-band filtering, wherein the electrolytic capacitor bears low-frequency ripple filtering, the ceramic capacitor processes high-frequency noise, and the tantalum capacitor improves the transient response capability, which together ensures the purity of the output voltage. The output end OUT of the voltage stabilizing chip U2 is electrically connected with the 9th pin of the MCU chip U9 through an independent power line, and the power line adopts a widened wiring design to reduce the line impedance, thereby providing a stable working voltage for the MCU.

[0105] Further, the connector J3 adopts a power supply interface with a mechanical locking structure, which can ensure the electrical connection stability when the external power supply is accessed, and avoid voltage fluctuation caused by poor contact. The selection of the voltage stabilizing chip U2 needs to meet the low dropout (LDO) characteristic and the high power supply rejection ratio (PSRR) requirement, so as to reduce the influence of input voltage fluctuation on the output. It should be understood that the capacitance of the capacitor CB6 and the capacitor CB7 needs to be configured according to the noise characteristics of the external power supply, and usually a ceramic capacitor with excellent high-frequency characteristics is selected, while the capacitors CB8 and CB9 at the output end can adopt a combination of electrolytic capacitors and ceramic capacitors to form a π-type filtering structure, which effectively attenuates noise components of different frequency bands.

[0106] Further, in terms of circuit board layout, the voltage stabilizing chip U2 should be placed close to the connector J3 to shorten the length of the input power supply line and reduce the line impedance, and the heat dissipation pad thereof is connected to the ground layer connector J4 through a via to ensure effective heat dissipation during the operation of the chip and avoid output voltage drift caused by temperature changes. The installation positions of the output capacitors CB8, CB9 and C5 should be close to the OUT pin of U2 to reduce the influence of parasitic inductance on the filtering effect. At the same time, the connection between the power supply pin of the MCU chip U9 and the output end of the power supply module should avoid crossing the high-frequency signal wire to prevent noise interference introduced by electromagnetic coupling.

[0107] In practical applications, if there is serious common-mode interference in the external power supply, a common-mode inductor can be added between J3 and the input end IN of U2 to form an LC filtering structure with the existing capacitor filtering network to enhance the suppression ability of common-mode noise. Through clear component connection and parameter configuration, the embodiment constructs a complete power supply link including input protection, voltage conversion and multi-stage filtering, provides a stable 5V working voltage for the back-end circuit, and meets the requirements of the MCU control module and each functional unit for power supply quality. Circuit designers can adjust the capacitance value and voltage stabilizing chip model according to the characteristics of the actual input power supply, while ensuring the stability of the power supply, taking into account the rationality of the circuit board layout and the manufacturing cost.

[0108] The benefits of the embodiment are that, through the connection relationship and functional division of the components of the power supply module, a hierarchical power supply processing architecture is formed, from the mechanical stability design of the input interface to the selection of the characteristics of the voltage stabilizing chip, and then to the frequency band coverage of the multi-stage filtering network, systematically solving the problem of power supply stability and laying a foundation for the reliable operation of the entire circuit system.

[0109] Embodiment Seven: To solve the problem of signal distortion or incorrect analysis of control commands caused by external interference in the host computer communication process, the embodiment further constructs the hardware circuit of the host computer communication module, and realizes reliable reception of external trigger signals and noise filtering through reasonable configuration of signal conditioning elements.

[0110] As Figure 2As shown in the figure, the host computer communication module takes interface J2 as the external signal input port, which receives the trigger input signal sent by the host computer and is connected with the 11th pin (i.e. the communication receiving pin) of MCU chip U9 through resistor R6. On the signal transmission path, resistor R2, diode D1 and capacitor C3 are connected in parallel between the 11th pin of U9 and the ground, forming a three-stage protection circuit: resistor R2 is connected in series with the signal path as a current-limiting resistor, which can limit the input current in abnormal conditions to avoid overcurrent damage to the MCU pin; diode D1 is a Schottky diode, with its cathode connected to the 3.3V power supply and its anode grounded, which can clamp the input voltage within a safe range to prevent external high-voltage signal impact; capacitor C3 is a filter capacitor connected in parallel between the pin and the ground, which can filter out high-frequency noise components to ensure the integrity of the input signal. In addition, capacitor C2 is connected in parallel between the host computer interface J2 and the ground, forming an input stage low-pass filter to further attenuate the coupled high-frequency interference signals during transmission.

[0111] Further, the host computer interface J2 adopts a standardized connector, whose mechanical structure ensures reliable connection with external cables and reduces the introduction of contact noise. The resistance value of resistor R6 needs to consider both signal attenuation and driving capability, usually a precision resistor that meets the circuit characteristic requirements is selected to avoid signal attenuation or overcurrent risk caused by improper resistance value. It should be understood that the clamping voltage of diode D1 needs to match the voltage withstand level of the MCU pin to ensure effective protection of the internal circuit when the external voltage is abnormal, and the capacitance configuration of capacitors C2 and C3 needs to be adjusted according to the target noise frequency to effectively filter out interference signals in specific frequency bands.

[0112] In the PCB layout design, the host computer interface J2 should be away from the power module and high-frequency signal traces to reduce electromagnetic coupling interference. The signal line connecting J2 and the MCU pin adopts a short straight trace to avoid the influence of parasitic capacitance introduced by long lines on signal transmission speed. The components of the protection circuit need to be placed close to the MCU pin to ensure that the noise is effectively suppressed before entering the internal circuit. At the same time, the ground end of the communication module is directly connected with the ground plane of the circuit board, forming a low-impedance return path to reduce the influence of ground loop noise on the signal.

[0113] In actual application, the host computer communication module supports UART serial communication protocol, and variable baud rate communication is realized by software configuration of the MCU's baud rate register. When the external trigger signal is input through J2, it is first filtered by capacitor C2, then processed by the protection circuit composed of resistor R2, diode D1 and capacitor C3, and finally transmitted to the 11th pin of U9. After receiving the signal, the MCU verifies the integrity of the data frame through the internal verification mechanism to ensure accurate analysis of the control command.

[0114] The embodiment constructs a complete input link containing signal filtering, overvoltage protection and noise suppression by explicitly determining the element composition and connection relationship of the host computer communication module, effectively improves the anti-interference ability of the communication interface, ensures the reliable transmission of the external trigger signal and the correct response of the MCU, and provides a stable hardware foundation for the real-time interaction between the host computer and the circuit system.

[0115] Embodiment eight: to solve the problems of insufficient driving capacity and waveform distortion of low-frequency carrier signal output, the circuit structure of the low-frequency carrier signal output module is further designed in this embodiment, and through the collaborative configuration of multi-stage amplification circuit and impedance matching network, high-precision output of fixed frequency signal is realized.

[0116] As shown in Figure 2 The signal path of the low-frequency carrier signal output module starts from the 12th pin (SDW CLK) of the MCU chip U9, which outputs the initial low-frequency carrier signal, and is connected to the gate of transistor Q2 after passing through the voltage division network composed of resistor R4 and resistor R7. Transistor Q2 is an N-type field effect transistor, the emitter is grounded, and the collector is connected to a 5V stable voltage source through resistor R1 and resistor R3, forming a first-stage amplification circuit to realize voltage amplification of the MCU output signal. Transistor Q1 is a P-type field effect transistor, its gate is connected between resistor R1 and resistor R3, the emitter is connected to a 5V power supply, and the collector is connected to output connector J1 through resistor R5, forming a second-stage amplification circuit and a complementary symmetrical structure with transistor Q2 to improve the driving capacity of the signal. The output end is connected in parallel with an RC filter circuit composed of resistor R8 and capacitor C1, which is used to filter out high-frequency harmonics and ensure the purity of the output waveform; resistor R9 is connected between J1 and ground to realize the matching of output impedance and load and reduce signal reflection.

[0117] Further, the voltage division ratio of resistor R4 and resistor R7 is designed according to the output level of the MCU pin and the turn-on voltage of transistor Q2, to ensure that transistor Q2 works in the linear amplification zone and avoid saturation distortion. The values of resistor R1 and resistor R3 need to consider the collector current of transistor Q2 and the gate drive voltage of transistor Q1, and through reasonable configuration, the two-stage amplification circuit forms gain cascade to meet the demand of driving long-distance transmission cable or high input impedance load. It should be understood that the selection of transistor Q1 and transistor Q2 needs to consider the transconductance parameter and voltage withstand grade, and usually low-noise field effect transistors are selected to reduce the noise components introduced in the amplification process.

[0118] In the signal transmission process, the low-frequency carrier signal output by the MCU is amplified by transistor Q2 and then drives transistor Q1. The collector output signal of transistor Q1 is transmitted to J1 through resistor R5. The filter circuit composed of resistor R8 and capacitor C1 suppresses the high-frequency oscillation of the rising and falling edges, ensuring that the output waveform meets the time-domain characteristics of the square wave signal. Resistor R9 acts as a matching resistor, and its resistance value is set according to the target load impedance to achieve maximum power transmission of the signal.

[0119] When laying out the circuit board, the wiring from the MCU pin to the amplifier circuit should be as short and straight as possible to reduce the influence of parasitic inductance on the signal edge. The heat dissipation pads of transistors Q1 and Q2 need to be connected to the ground layer to avoid work point drift caused by temperature rise. The output connector J1 uses a standardized interface, and its internal impedance matches the external test equipment to ensure the consistency of signal transmission.

[0120] In practical applications, if the target load has specific requirements for signal amplitude, the voltage amplitude of the output signal can be adjusted by adjusting the resistance values of resistors R1 and R3 to change the power bias of the amplifier circuit. The RC parameters of the filter circuit need to be designed according to the frequency of the low-frequency carrier signal to retain the fundamental component and attenuate higher harmonics.

[0121] This embodiment constructs a complete signal path including voltage division bias, two-stage amplification, and impedance matching by clearly defining the element connection and circuit architecture of the low-frequency carrier signal output module, effectively improving the driving capability and waveform quality of the signal, ensuring high-precision output of the fixed-frequency and timing low-frequency carrier signal, and meeting the requirements of related tests on the signal source.

[0122] Example Nine: To solve the consistency problem of hardware implementation of collision signal simulation and state indication function, this embodiment further constructs the circuit structure of the collision signal simulation module and the state indication module, and realizes reliable output of the PWM collision signal and intuitive feedback of the working state by clearly defining the element connection and signal path.

[0123] As shown in Figure 2 In the collision signal simulation module, the 14th pin of MCU chip U9 outputs the PWM collision signal, which is connected to the gate of transistor Q3 after passing through the voltage division network composed of resistors R10 and R11. Transistor Q3 is an N-type field effect transistor, with the emitter connected to the ground and the collector directly connected to the output connector J5, forming a common-source amplifier circuit. It converts the 3.3V level signal output by the MCU into a 5V amplitude driving signal to meet the input level requirements of the automotive electronic collision sensor. Resistor R10 acts as a current-limiting resistor to protect the MCU pin from excessive current impact, and resistor R11 is used to set the static working point of transistor Q3 to ensure that it works in the linear amplification region and avoids signal distortion.

[0124] Further, the state indication module adopts a dual-color indicator lamp design, the 19th pin (LED_R) of the MCU is directly connected to the red indicator lamp, and the 20th pin (LED_G) is connected to the green indicator lamp and then connected to the 5V stabilized power supply through the resistor R15. The red indicator lamp is used to indicate the collision signal output state, when the U9 outputs the PWM collision signal, the LED_R pin outputs low level, making the red indicator lamp conductive and emitting light; the green indicator lamp indicates the normal signal output state, the LED_G pin is pulled up to 5V through the resistor R15, when the low-frequency carrier signal is output, the pin remains high level, and the green indicator lamp is lit. The resistor R15 acts as a current limiting resistor to limit the working current of the indicator lamp, ensuring uniform brightness and prolonging the service life.

[0125] Further, the selection of the transistor Q3 needs to consider the switching speed and current driving capability to ensure the fast response and accurate amplification of the PWM signal. The connector J5 adopts a mistaken insertion prevention design, which matches the input interface of the collision sensor, avoiding circuit damage caused by connection errors. The layout of the status indicator lamp is located on the front panel of the circuit board, which is convenient for operators to intuitively identify, and the driving circuit and signal amplification circuit of the indicator lamp are independent on the power supply loop, reducing electromagnetic interference between each other.

[0126] It should be understood that the power supply of the amplification circuit of the collision signal simulation module is taken from the independent power supply circuit of the power supply module, which is physically separated from the power supply path of the MCU control module, avoiding the influence of current fluctuation caused by PWM signal switching on the stable work of the MCU. The indicator lamp pin of the state indication module is directly controlled through the GPIO port, and the MCU can switch the indicator lamp state in real time according to the current signal output mode, realizing the visual feedback of human-computer interaction.

[0127] When laying out the PCB, the output line of the collision signal simulation module and the driving line of the status indicator lamp should be away from the high-frequency digital signal line to reduce the crosstalk influence. The gate line of the transistor Q3 needs impedance control to avoid the parasitic capacitance introduced by the too long line causing signal edge delay. The installation position of the indicator lamp needs to consider the viewing angle range to ensure that the state can be clearly identified under different lighting conditions.

[0128] In practical application, if it is necessary to adjust the brightness of the indicator lamp, the resistance value of the resistor R15 can be changed; if the input impedance of the collision sensor is high, a matching resistor can be connected in parallel at the output end of J5 to improve the stability of signal transmission. The control logic of the state indication module works cooperatively with the signal generation module, when the MCU receives the mode switching instruction from the upper computer, the indicator lamp state is updated synchronously, ensuring the consistency of hardware indication and software configuration.

[0129] The embodiment realizes the hardware implementation of the PWM signal amplification path and the state feedback mechanism through the circuit detail design of the collision signal simulation module and the state indication module, ensures the reliable output and level conversion of the collision signal, and realizes the intuitive display of the working state through the double-color indicating lamp, thereby providing convenience for the operation and maintenance of related equipment.

[0130] Embodiment ten: in order to solve the problems of dispersed function modules, low collaborative control efficiency and insufficient adaptability of the existing signal generating device, the embodiment further constructs the overall architecture of the programmable low-frequency carrier radio frequency signal generating system, realizes the collaborative work and parameter linkage among the modules through the modular division and systematic integration of the function units, and meets the signal generation demand in the complex test scene.

[0131] The generating system takes the MCU chip U9 as the control center, internally embeds the signal generation algorithm and the communication protocol stack, and realizes the real-time adjustment of the signal parameters through the preset register configuration. Specifically, the 9th pin of the MCU chip U9 is connected with the 5V output end of the power supply unit to obtain a stable working voltage; the 11th pin receives the instruction data sent by the external device through the host computer communication module, generates the corresponding control signal after internal analysis, and transmits the control signal to the signal generation unit and the state indication module respectively. In terms of signal parameter configuration, the MCU chip U9 outputs the clock control signal of the low-frequency carrier signal through the 12th pin, and outputs the duty ratio and frequency adjustable signal of the PWM collision signal through the 14th pin. The timing relationship of the two types of signals is accurately synchronized by the internal timer module, so as to ensure the phase consistency of the output signal. It should be understood that the software architecture of the control unit supports modular programming, allows users to customize the signal waveform parameters through the host computer software, and updates the register configuration in the MCU in real time after instruction analysis, so as to realize the programmability of signal generation.

[0132] Further, the power supply unit integrates a multi-stage filtering and voltage stabilization conversion circuit. The input end of the power supply unit is connected to the external power supply VCC through the connector J3, and after being converted into a 5V stable voltage by the voltage stabilization chip U2, the power supply unit supplies power to the control unit, the signal generation unit and the man-machine interaction unit through independent power supply lines. The input stage of the power supply unit is configured with capacitors CB6 and CB7 to suppress high-frequency noise, and the output stage is configured with a π-type filtering network composed of capacitors CB8, CB9 and C5 to reduce the influence of power supply ripple on signal generation accuracy. It should be noted that the power supply unit and the signal generation unit adopt single-point grounding design, which avoids the mutual interference of ground currents of different function modules, ensures the separation of the ground planes of analog signals and digital signals, and improves the electromagnetic compatibility (EMC) of the system.

[0133] Further, the signal generating unit includes a low-frequency carrier signal output module and a collision signal simulation module, which realize differentiated signal output under the coordination of the control unit. The low-frequency carrier signal output module takes the 12th pin of the MCU chip U9 as the signal source, drives the transistor Q2 after voltage division by the resistor R4 and the resistor R7, and enhances the signal driving capability through the complementary amplification circuit composed of the transistors Q1 and Q2, and finally outputs the low-frequency carrier signal of fixed frequency time sequence through the connector J1. The resistor R8 and the capacitor C1 of the module constitute an output filter network to suppress high-frequency harmonic components and ensure the purity of the signal waveform; the resistor R9 serves as a load matching resistor, which can be adjusted according to the input impedance of the external test equipment to reduce signal reflection loss. The collision signal simulation module outputs a PWM signal with configurable parameters through the 14th pin of the MCU chip U9, controls the conduction state of the transistor Q3 after voltage division by the resistor R10 and the resistor R11, and outputs a 5V amplitude collision signal meeting the automotive electronic test standard through the connector J5. The duty cycle and frequency parameters can be modified in real time through the host computer command to meet the signal simulation requirements under different test conditions.

[0134] Further, the human-computer interaction unit builds a bidirectional interaction channel between the system and external devices and operating personnel. The host computer communication module receives external control commands through the host computer interface J2, filters out interference through the signal conditioning circuit composed of the resistor R6, the resistor R2, the diode D1, the capacitor C2 and the capacitor C3, and then transmits to the 11th pin of the MCU chip U9, supporting UART, SPI and other serial communication protocols, and compatible with the control software of mainstream test equipment. The state indication module adopts a double-color indicator lamp design. The red indicator lamp is directly connected to the 19th pin of the MCU (LED_R), which is used to indicate the output state of the collision signal. When the PWM collision signal is generated, the pin outputs a low level to make the red light on. The green indicator lamp is connected to the 20th pin of the MCU (LED_G) after being pulled up to 5V through the resistor R15, which indicates the normal signal output state. The green light remains on when the low-frequency carrier signal is working. The two types of indicator lamps are arranged on the front panel of the system, using high-brightness surface-mounted LEDs, and cooperating with transparent light guides to realize visual feedback of the state, which is convenient for operating personnel to monitor the working mode of the equipment in real time.

[0135] Further, the system hardware architecture adopts a layered circuit board design, the digital circuit layer of the control unit, the analog circuit layer of the signal generation unit and the power circuit layer of the power supply unit are isolated by a shielding layer to reduce interlayer electromagnetic coupling. The signal output interfaces such as connectors J1 and J5 adopt metal shell shielding, and cooperate with grounding springs to realize 360° electromagnetic shielding, thereby reducing the influence of external interference on the output signal. The peripheral circuit of the MCU chip U9 is configured with a decoupling capacitor placed close to the chip power supply pin to suppress high-frequency noise interference on the control logic. It should be understood that the software design of the system includes a fault diagnosis mechanism, which sends a warning signal through the flashing combination of the status indicator light when detecting abnormal power voltage or signal output overrun, and sends an error code to the upper computer, thereby improving the reliability and maintainability of the device.

[0136] In actual application scenarios, the system can preset multiple groups of signal parameter combinations through the upper computer software, support one-key switching of different test modes, and meet the collaborative test requirements of low-frequency carrier signals and collision simulation signals in the fields of automotive electronics, Internet of Things devices and the like. The output connector of the signal generation unit adopts a standardized interface, is compatible with industry general test fixtures, and reduces signal loss caused by adapter conversion. The power supply unit supports a wide voltage input range, and by replacing the model of the voltage stabilizing chip U2, different external power supplies such as 12V and 24V can be adapted, thereby improving the environmental adaptability of the device.

[0137] The benefits of the embodiment are that by integrating the control unit, the power supply unit, the signal generation unit and the human-computer interaction unit, a signal generation system architecture with functional modularization and programmable control is constructed, each unit has independent hardware design logic, and through a standardized interface, the collaborative transmission of signals and energy is realized, ensuring the high-precision generation, flexible parameter configuration and real-time state feedback of low-frequency carrier signals and PWM collision signals, and providing a systematic solution for device testing in complex electromagnetic environments. Circuit designers can adjust the element parameters and interface forms of each unit according to the target application scenario, balance the functions of extension and cost optimization under the premise of maintaining the integrity of the system architecture.

[0138] Although the present application has been described above with specific reference to the preferred embodiments thereof, it is to be understood that this application is not limited to the above-described embodiments, but that various modifications and changes can be made thereto without departing from the spirit and scope of the present application.

Claims

1. A programmable low frequency carrier radio frequency signal coordinated control method, characterized by, The method comprises the following steps: Access the input voltage through the external power supply interface, convert it into a 5V stable working voltage through a voltage stabilizing chip, and supply power to the MCU control module and each functional module after parallel multi-stage filtering capacitors filter out power supply noise; The MCU control module generates two signals: one is a low-frequency carrier signal generated according to a preset frequency and time sequence, which is driven by a two-stage transistor amplification circuit and output to an external device through an output interface; the other is a specified PWM signal generated according to a vehicle body collision signal characteristic parameter, which is output through a transistor drive circuit and an independent interface for simulating a collision condition; The upper computer communication module receives an external trigger input signal, which is transmitted to the MCU control module after current limiting, clamping and filtering processing by a signal conditioning circuit, for the external device to control the working mode of the circuit and configure parameters. The MCU control module drives a double-color indicator light according to the current working state: when the PWM collision signal is output, the red indicator light is lit; when the normal low-frequency carrier signal is output, the green indicator light is lit, for quick identification of the working mode.

2. The programmable low frequency carrier radio frequency signal co- control method of claim 1, wherein, The external power supply is connected through a connector, voltage conversion is realized through a voltage stabilizing chip, a high-frequency filtering capacitor is connected in parallel at the input end to suppress surge interference, and a π-type filter circuit is formed by connecting multiple groups of capacitors with different capacitances in parallel at the output end, so that the output voltage ripple is less than 50mV. The stable 5V power supply directly supplies power to the MCU chip and supplies power to the signal amplification circuit and the indication module through an independent power line, so as to avoid power supply noise coupling between different modules.

3. The programmable low frequency carrier radio frequency signal co- control method of claim 1, wherein, The frequency, pulse width and output time sequence of the low-frequency carrier signal are configured by the internal timer of the MCU control module, a square wave signal with a frequency of 10KHz and a pulse width of 100ms is output, the driving capacity is improved through a Darlington amplification circuit composed of two-stage NPN transistors, a matching resistor is connected in series at the output end and an RC filter circuit is connected in parallel, for suppressing high-frequency harmonics and realizing 50Ω impedance matching. The duty cycle and period parameters of the PWM collision signal can be configured through the upper computer software, a pulse signal with a duty cycle of 50% and a frequency of 2Hz is generated, and the signal is output through a transistor common-emitter amplification circuit and an interface, so as to meet the signal simulation requirements of the automobile electronic collision sensor.

4. The programmable low frequency carrier radio frequency signal co- control method of claim 1, wherein, The interface of the upper computer adopts a single-ended signal input mode, the input signal is processed by a protection circuit composed of a current limiting resistor, a voltage stabilizing diode and a filtering capacitor, the voltage amplitude is clamped to a safety range of 3.3V, and high-frequency noise is filtered out before being connected to the communication pin of the MCU; The communication protocol adopts UART serial communication, supports adjustable baud rate from 9600 to 115200, so as to realize remote configuration and real-time monitoring of the signal output mode, frequency parameters and indicator light state by the external upper computer.

5. A programmable low-frequency carrier radio frequency signal coordination circuit for carrying out the programmable low-frequency carrier radio frequency signal coordination method according to any one of claims 1 to 4, characterized in that It comprises: a power module for providing a stable working voltage; an MCU control module containing an MCU chip U9 for generating a low-frequency carrier signal, a PWM collision signal and controlling a state indication; an upper computer communication module for realizing signal interaction with an external upper computer; a low-frequency carrier signal output module for outputting a low-frequency carrier signal with a fixed frequency and time sequence; a collision signal simulation module for outputting a specified PWM signal to simulate a vehicle body collision signal. A state indicating module is configured to display the working state of the indicator light circuit. The power module is electrically connected with the MCU control module, and the upper computer communication module, the low-frequency carrier signal output module, the collision signal simulation module and the state indicating module are respectively electrically connected with the MCU control module.

6. The programmable low frequency carrier RF signal coπtrol circuit of claim 5 wherein, The power module comprises: A connector J3 is configured to access an external power supply VCC; A connector J4 is configured to ground GND; A voltage stabilizing chip U2 has an input end IN connected with the connector J3 and an output end OUT outputting a 5V voltage stabilizing power supply; Capacitors CB6, CB7 are connected in parallel between the connector J3 and the connector J4; Capacitors CB8, CB9 and C5 are connected in parallel between the output end OUT of the voltage stabilizing chip U2 and the connector J4; The output end OUT of the voltage stabilizing chip U2 is electrically connected with the 9th pin of the MCU chip U9.

7. The programmable low frequency carrier RF signal coπtrol circuit of claim 5, wherein, The upper computer communication module comprises: An upper computer interface J2 is connected with the 11th pin of the MCU chip U9 through a resistor R6; A resistor R2, a diode D1 and a capacitor C3 are connected in parallel between the 11th pin of the MCU chip U9 and the ground; A capacitor C2 is connected in parallel between the upper computer interface J2 and the ground; The upper computer interface J2 is configured to receive a trigger input signal of an external upper computer and transmit the signal to the MCU chip U9.

8. The programmable low frequency carrier RF signal coπtrol circuit of claim 5, wherein, The low-frequency carrier signal output module comprises: A resistor R4 and a resistor R7 are connected in series, with one end grounded and the other end connected with the 12th pin (SDW_CLK) of the MCU chip U9; A transistor Q2 has its gate connected between the resistor R4 and the resistor R7, its emitter grounded and its collector connected with a 5V voltage stabilizing power supply through a resistor R1 and a resistor R3; A transistor Q1 has its gate connected between the resistor R1 and the resistor R3, its emitter connected with a 5V voltage stabilizing power supply and its collector connected with a connector J1 through a resistor R5; A resistor R8 and a capacitor C1 are connected in parallel between the collector of the transistor Q1 and the ground; A resistor R9 is connected between the connector J1 and the ground; The connector J1 is configured to output a low-frequency carrier signal generated by the MCU chip U9.

9. The programmable low frequency carrier RF signal coπtrol circuit of claim 5, wherein, In the collision signal simulation module, a resistor R10 and a resistor R11 are connected in series, with one end grounded and the other end connected with the 14th pin of the MCU chip U9, and a transistor Q3 has its gate connected between the resistor R10 and the resistor R11, its emitter grounded and its collector connected with a connector J5, which is configured to output a PWM collision signal; In the state indicating module, the 19th pin (LED_R) of the MCU chip U9 is connected with a red indicator light, and the 20th pin (LED_G) is connected with a green light, which is then connected with a 5V voltage stabilizing power supply through a resistor R15; The red indicator light is configured to indicate the collision signal output state, and the green light is configured to indicate the normal signal output state.

10. A programmable low frequency carrier radio frequency signal generation system incorporating a programmable low frequency carrier radio frequency signal co-ordination control circuit as claimed in any one of claims 5 to 9, characterised in that, The control unit comprises a MCU chip U9, which is configured to execute a signal generation algorithm, analyze upper computer instructions and control state indication, and configure parameters and control timing of low-frequency carrier signals and PWM collision signals. ​ The power supply unit includes a power module, which is used for converting an external input power supply into a 5V stable voltage, suppressing power supply noise through a multi-stage filtering circuit, and providing pure power supply; The signal generation unit includes a low-frequency carrier signal output module and a collision signal simulation module, which are respectively used for generating a low-frequency carrier signal with a fixed frequency time sequence and a PWM collision signal with configurable parameters to meet the signal output requirements of different test scenarios; The human-computer interaction unit includes a host computer communication module and a state indication module, which realizes the input of control instructions of external equipment through a host computer interface and realizes the visual feedback of the working state through a double-color indicating lamp.

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