Cooperative control method, circuit and generation system for programmable low-frequency carrier radio-frequency signals

Abstract

The invention 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 generation system. Comprising the following steps of: accessing an input voltage through an external power supply interface, converting the input voltage into a 5V stable working voltage through a voltage stabilizing chip, and supplying power to an MCU (Microprogrammed Control Unit) control module and each functional module after a multi-stage filter capacitor is connected in parallel to filter power supply noise. According to the invention, by constructing an integrated programmable signal cooperative control architecture, the technical problems of accurate generation and reliable interaction of multiple signals in a complex test scene are effectively solved. Specifically, the cooperative control method ensures that the MCU and the signal output module obtain a pure 5V power supply with ripple less than 50mV through a multistage filtering design and an independent power supply strategy of the power supply module, inhibits noise coupling from a power supply end, and improves the stability of signal generation.

Description

Technical Field

[0001] This invention relates to the field of automotive electronic control system testing technology, specifically to a programmable low-frequency carrier radio frequency signal cooperative control method, circuit, and generation system. Background Technology

[0002] Accurate simulation of low-frequency carrier signals and vehicle collision signals is a crucial technical step in verifying the reliability of onboard sensors and communication modules. Existing signal generation equipment typically employs a fixed hardware architecture to achieve a single signal output, or generates multiple signals through discrete module combinations. However, this approach generally suffers from the following technical bottlenecks: Firstly, the coordinated control of low-frequency carrier signals and collision signals relies on complex external timing circuits, limiting the programmable configuration capabilities of signal frequency, pulse width, and timing, making it difficult to adapt to the diverse testing needs of sensors from different vehicle models. Secondly, the interaction interface between the signal output module and the host computer lacks an effective signal conditioning and protection mechanism, making it susceptible to external electromagnetic interference that can lead to misinterpretations of control commands. Furthermore, status feedback is only achieved through a single indicator light or host computer software, making it impossible to quickly identify the operating mode during on-site operation. In addition, the power supply module's filtering design is insufficient, allowing high-frequency noise to easily couple into the signal generation circuit, causing output signal distortion and affecting the accuracy of test results. Therefore, how to achieve multi-signal programmable coordinated control, highly reliable human-machine interaction, and low-noise power supply within a compact circuit architecture has become a key technical challenge hindering the performance improvement of onboard signal simulation equipment. Summary of the Invention

[0003] This disclosure proposes a programmable low-frequency carrier radio frequency signal cooperative control method, circuit and generation system, with the aim of overcoming at least one of the defects in the prior art.

[0004] To achieve the above objectives, the technical solution disclosed in this invention is as follows: According to one aspect of this disclosure, a programmable low-frequency carrier radio frequency signal cooperative control method is provided, comprising the following steps: The input voltage is connected through an external power interface, converted into a stable 5V operating voltage by a voltage regulator chip, and then filtered out by multiple parallel filter capacitors to provide power to the MCU control module and various functional modules. The MCU control module generates two types of signals: First, a low-frequency carrier signal is generated according to a preset frequency and timing, driven by a two-stage transistor amplifier circuit, and output to an external device through an output interface; Second, a specified PWM signal is generated according to the characteristic parameters of the vehicle collision signal, and output through an independent interface after passing through a transistor drive circuit, for simulating collision conditions. The external trigger input signal is received through the host computer communication module. After being processed by the signal conditioning circuit for current limiting, clamping and filtering, it is transmitted to the MCU control module for external devices to control the circuit's working mode and configure parameters. The MCU control module drives a dual-color indicator light according to the current working state: the red indicator light is lit when a PWM collision signal is output, and the green indicator light is lit when a normal low-frequency carrier signal is output, for quick identification of the working mode.

[0005] Furthermore, the external power supply is connected through a connector, and the voltage is converted by a voltage regulator chip. A high-frequency filter capacitor is connected in parallel at the input end to suppress surge interference, and multiple sets of capacitors with different capacitance values ​​are connected in parallel at the output end to form a π-type filter circuit, with the output voltage ripple being less than 50mV. The stabilized 5V power supply directly powers the MCU chip and supplies power to the signal amplification circuit and indicator module through an independent power line to avoid power noise coupling between different modules.

[0006] Furthermore, the frequency, pulse width, and output timing of the low-frequency carrier signal are configured by the internal timer of the MCU control module, outputting a square wave signal with a frequency of 10KHz and a pulse width of 100ms. The driving capability is enhanced by a Darlington amplifier circuit composed of two NPN transistors. The output terminal is connected in series with a matching resistor and in parallel with an RC filter circuit to suppress high-frequency harmonics and achieve 50Ω impedance matching. The duty cycle and period parameters of the PWM collision signal can be configured by the host computer software to generate a pulse signal with a 50% duty cycle and a 2Hz frequency. After passing through the transistor common emitter amplifier circuit, the signal is output through the interface to meet the signal simulation requirements of the automotive electronic collision sensor.

[0007] Furthermore, the host computer's interface adopts a single-ended signal input method. The input signal is processed by a protection circuit consisting of a current-limiting resistor, a Zener diode, and a filter capacitor to clamp the voltage amplitude to a safe range of 3.3V. After filtering out high-frequency noise, it is connected to the MCU's communication pin. The communication protocol uses UART serial communication and supports an adjustable baud rate of 9600 to 115200 to enable remote configuration and real-time monitoring of signal output mode, frequency parameters and indicator status by an external host computer.

[0008] According to another aspect of this disclosure, a programmable low-frequency carrier radio frequency signal cooperative control circuit is provided for executing the programmable low-frequency carrier radio frequency signal cooperative control method described above, comprising: The power module is used to provide a stable operating voltage; The MCU control module, including the MCU chip U9, is used to generate low-frequency carrier signals, PWM collision signals, and control status indicators. The host computer communication module is used to realize signal interaction with an external host computer; Low-frequency carrier signal output module, used to output low-frequency carrier signals with fixed frequency and timing; The collision signal simulation module is used to output a specified PWM signal to simulate a vehicle collision signal; The status indicator module is used to display the circuit's operating status via indicator lights; The power supply module is electrically connected to the MCU control module, and the host computer communication module, low-frequency carrier signal output module, collision signal simulation module and status indication module are respectively electrically connected to the MCU control module.

[0009] Furthermore, the power module includes: Connector J3 is used to connect to an external power supply VCC; Connector J4, ground (GND); The voltage regulator chip U2 has its input terminal IN connected to the connector J3, and its output terminal OUT outputs a 5V regulated power supply. Capacitors CB6 and CB7 are connected in parallel between connectors J3 and J4; Capacitors CB8, CB9, and C5 are connected in parallel between the output terminal OUT of the voltage regulator chip U2 and connector J4. The output terminal OUT of the voltage regulator chip U2 is electrically connected to pin 9 of the MCU chip U9.

[0010] Furthermore, the host computer communication module includes: The host computer interface J2 is connected to pin 11 of the MCU chip U9 via resistor R6; Resistor R2, diode D1, and capacitor C3 are connected in parallel between pin 11 of the MCU chip U9 and ground; Capacitor C2 is connected in parallel between the host computer interface J2 and ground; The host computer interface J2 is used to receive trigger input signals from an external host computer and transmit them to the MCU chip U9.

[0011] Furthermore, the low-frequency carrier signal output module includes: Resistors R4 and R7 are connected in series, with one end grounded and the other end connected to pin 12 (SDW_CLK) of the MCU chip U9. Transistor Q2 has its gate connected between resistors R4 and R7, its emitter grounded, and its collector connected to a 5V regulated power supply through resistors R1 and R3. Transistor Q1 has its gate connected between resistors R1 and R3, its emitter connected to a 5V regulated power supply, and its collector connected to connector J1 through resistor R5. Resistor R8 and capacitor C1 are connected in parallel between the collector of transistor Q1 and ground; Resistor R9 is connected between connector J1 and ground; The connector J1 is used to output the low-frequency carrier signal generated by the MCU chip U9.

[0012] Furthermore, the collision signal simulation module and the status indication module include: In the collision signal simulation module, resistors R10 and R11 are connected in series, with one end grounded and the other end connected to pin 14 of the MCU chip U9. The gate of transistor Q3 is connected between resistors R10 and R11, the emitter is grounded, and the collector is connected to connector J5. Connector J5 is used to output PWM collision signals. In the status indication module, pin 19 (LED_R) of the MCU chip U9 is connected to a red indicator light, and pin 20 (LED_G) is connected to a 5V regulated power supply through resistor R15 and then connected to a green light. The red indicator light is used to indicate the collision signal output status, and the green light is used to indicate the normal signal output status.

[0013] According to another aspect of this disclosure, a programmable low-frequency carrier radio frequency signal generation system is provided, integrating the programmable low-frequency carrier radio frequency signal cooperative control circuit as described above, comprising: The control unit, including the MCU chip U9, is used to execute signal generation algorithms, parse host computer instructions and control status indications, and configure and control the parameters and timing of low-frequency carrier signals and PWM collision signals. The power supply unit, including the power module, is used to convert the external input power into a stable 5V voltage, suppress power supply noise through a multi-stage filtering circuit, and provide clean power supply. The signal generation unit includes a low-frequency carrier signal output module and a collision signal simulation module, which are used to generate a low-frequency carrier signal with fixed frequency timing and a PWM collision signal with configurable parameters, respectively, to meet the signal output requirements of different test scenarios. The human-computer interaction unit includes a host computer communication module and a status indication module. It realizes the input of control commands from external devices through the host computer interface and realizes the visual feedback of working status through dual-color indicator lights.

[0014] The beneficial effects of this invention are: This invention effectively solves the technical challenge of accurate generation and reliable interaction of multiple signals in complex testing scenarios by constructing an integrated programmable signal cooperative control architecture. Specifically, the cooperative control method ensures that the MCU and signal output module receive a clean 5V power supply with ripple of less than 50mV through multi-stage filtering design and independent power supply strategy of the power module, suppressing noise coupling from the power supply end and improving the stability of signal generation.

[0015] Furthermore, the MCU control module dynamically configures the frequency, pulse width, and timing of the low-frequency carrier signal based on its internal timer, and achieves low-distortion output of the 10KHz square wave signal through a Darlington amplifier circuit and an RC matching network. At the same time, it supports remote configuration of the duty cycle and period of the PWM collision signal by the host computer, thus meeting the high-precision simulation requirements of automotive electronic collision sensors.

[0016] Furthermore, the current limiting, clamping, and filtering protection circuits of the host computer communication module stabilize the input signal amplitude within a safe range of 3.3V. Combined with the adjustable baud rate communication of the UART protocol, this enables interference-resistant transmission of control commands and real-time parameter configuration. In addition, the status indicator module, through its independently driven dual-color indicator lights, allows operators to quickly determine the current output mode without relying on the host computer interface, improving on-site testing efficiency.

[0017] This invention achieves a technological breakthrough in a single circuit system by synergistically optimizing hardware circuits and control methods, enabling programmable signal generation, reliable interactive interfaces, and intuitive status feedback. It provides a high-precision and highly adaptable signal simulation solution for the automated testing of vehicle-mounted electronic devices.

[0018] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0019] Figure 1 This is a flowchart of the programmable low-frequency carrier radio frequency signal cooperative control method of the present invention; 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

[0020] 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.

[0021] 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.

[0022] The present invention provides the following preferred embodiments: 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.

[0023] like Figure 1 As shown, the flow of the collaborative control method is as follows: 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.

[0024] S200: Generates two types of signals using the MCU control module: 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; 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.

[0025] S300: Receives external trigger input signals through the host computer communication module, performs current limiting, clamping and filtering processing by the signal conditioning circuit, and then transmits them to the MCU control module for external devices to control the circuit's operating mode and configure parameters.

[0026] S400: The MCU control module drives a dual-color indicator light according to the current working state: the red indicator light is lit when a PWM collision signal is output, and the green indicator light is lit when a normal low-frequency carrier signal is output, which is used for quick identification of the working mode.

[0027] In implementation, a stable power supply system is first constructed: the external input voltage is connected through a dedicated power interface, which employs a reverse connection protection design to enhance circuit safety. The input voltage is first level-shifted by a voltage regulator chip, stabilizing the fluctuating input voltage to a 5V operating voltage. Considering the interference of power supply noise on high-frequency signal generation, multiple stages of filter capacitors are connected in parallel on both the input and output sides of the voltage regulator chip, forming a high-frequency noise attenuation path. The input-side capacitors suppress surge interference introduced by the external power supply, while the output-side capacitors utilize a combination of different capacitance values, such as ceramic capacitors with excellent high-frequency characteristics combined with electrolytic capacitors with significant low-frequency filtering effects, to form a composite filter network that effectively filters out power supply ripple. The stabilized voltage after this processing supplies power to the MCU control module and various functional modules through independent power lines, avoiding power supply noise coupling between the power module and the signal processing module, and providing a clean energy foundation for subsequent signal generation.

[0028] Furthermore, in the signal generation stage, the MCU control module, as the core processing unit, utilizes its internally integrated high-precision timer resources to achieve time-division or parallel generation of two signals with different characteristics through software programming. For the low-frequency carrier signal, based on preset frequency and timing parameters, the MCU outputs an initial pulse signal. This signal first undergoes a two-stage transistor amplification circuit to enhance its driving capability. The first stage transistor amplifies the small signal, while the second stage transistor further enhances the current driving capability, ensuring the signal can effectively drive the external load. The amplified signal is then transmitted to external devices through a dedicated output interface. This interface employs impedance matching design to reduce reflection loss during signal transmission. For collision simulation requirements, the MCU generates a specific PWM signal based on typical characteristics of vehicle collision signals, such as pulse width and repetition frequency. Distinguished from the processing path of the low-frequency carrier signal, the PWM signal is amplified through an independent transistor drive circuit and output through an independent interface, avoiding crosstalk between the two signals during transmission. This architecture of independent dual-signal generation and output ensures isolation between the two signals in terms of frequency characteristics, driving method, and transmission path, meeting the high-precision simulation requirements of different signal types in automotive electronics testing.

[0029] Furthermore, the reliability of the host computer communication module, serving as the input channel for external control commands, directly impacts the programmability of the entire system. After the external trigger input signal enters the circuit through the communication interface, it undergoes preprocessing by a signal conditioning circuit. Current-limiting resistors suppress the impact of abnormally large currents on subsequent circuits, Zener diodes clamp the signal amplitude within the safe voltage range acceptable to the MCU, and filter capacitors remove high-frequency noise, forming a three-level protection mechanism to ensure the integrity and safety of the input signal. The conditioned signal is then transmitted to the MCU control module, supporting remote control of the circuit's 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 adopts a universal serial communication standard, supporting adaptive baud rate adjustment to ensure compatibility with different host computer models and achieve reliable interaction of control commands.

[0030] Furthermore, to enhance the convenience of on-site operation, the status indicator module adopts a dual-color indicator light design, driven in real time by the MCU control module according to the current working status. When the system outputs a PWM collision signal, the MCU sends a high-level signal to the red indicator light driver circuit, illuminating the red indicator light and indicating that the system is currently in collision simulation mode. When a normal low-frequency carrier signal is output, the green indicator light is activated, indicating that the system is in normal signal output mode. The two indicator lights use independent driver circuits to avoid mutual interference, and the brightness and response speed of the indicator lights have been optimized through circuit parameters to ensure clear identification under different lighting conditions. This visual status feedback mechanism allows operators to quickly determine the system's working status through intuitive light indicators without relying on a host computer software interface, thus improving testing efficiency.

[0031] Furthermore, 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 circuits operate in a stable power environment. The separate design of the dual signal generation paths, through dedicated amplification circuits and independent output interfaces, avoids mutual interference between signals and ensures the waveform quality of the output signal. The signal conditioning circuit of the host computer communication module effectively enhances the system's immunity to external electromagnetic interference, ensuring accurate interpretation of control commands. The dynamic driving mechanism of the dual-color indicator lights establishes a simple and efficient human-machine interface, realizing real-time mapping of working modes. Through the organic combination of electrical connections and logic control, the various functional modules form a complete collaborative control system, which not only meets the stringent requirements of automotive electronic testing for signal accuracy but also improves the convenience and reliability of equipment operation.

[0032] It should be understood that the specific models and parameters of the hardware components such as the external power interface, voltage regulator chip, transistor amplifier circuit, and indicator light driver circuit in this embodiment can be adaptively adjusted according to the actual application scenario. This embodiment aims to achieve programmable coordinated control of low-frequency carrier signals and collision simulation signals through the control logic and circuit architecture constructed using the above method. Through technical solutions such as power stability assurance, independent signal generation design, protective conditioning of the communication interface, and intuitive status indication, this embodiment provides a standardized signal control solution for vehicle-mounted electronic testing equipment, effectively solving the problem of coordinated control when multiple signals are output.

[0033] Example 2: To solve the problem of signal distortion caused by power supply noise coupling in existing vehicle signal simulation equipment, this example optimizes the power supply system design. Through connector physical interface specifications, multi-level filter network construction, and independent power supply strategy, noise suppression of the power supply link is achieved, providing a stable and clean operating voltage for the core circuit.

[0034] In implementation, the external power supply is connected to the circuit via a dedicated power connector. This connector employs a mechanical locking structure to ensure the stability of the electrical connection, and its input terminal is directly connected to the input pin of the voltage regulator chip. The voltage regulator chip is a low-dropout LDO type with high power supply rejection ratio (PSRR) characteristics, capable of stably converting the input voltage to a 5V DC output. High-frequency ceramic capacitors with excellent characteristics are connected in parallel at the input of the voltage regulator chip to suppress surge voltage and high-frequency noise introduced by the external power supply, forming the first stage of filtering protection. At the output, a π-type filter circuit is constructed using multiple sets of capacitors with different capacitance values ​​connected in parallel—including electrolytic capacitors to filter low-frequency ripple, high-frequency ceramic capacitors to absorb switching noise, and tantalum capacitors to improve transient response capability. Through a capacitance gradient configuration, noise attenuation across the entire frequency band is achieved, ultimately controlling the output voltage ripple to within 50mV.

[0035] Furthermore, the stabilized 5V power supply provides power to the MCU chip, signal amplification circuit, and indicator module via independent power lines. The MCU chip's power supply line employs a single-point grounding design, and the power line width is widened to reduce line impedance and ensure the power supply stability of the digital core unit. The signal amplification circuit, as a power module, has its power line physically separated from the MCU's power supply line to prevent noise interference from current fluctuations during operation. The indicator module's power supply line uses a small-value resistor in series to limit the indicator light's operating current and reduce its impact on the main power supply. This distributed power supply architecture, through optimized circuit board layout, achieves physical power isolation between different functional modules, effectively preventing noise coupling between the power module and the signal processing module.

[0036] Furthermore, the power connector's ground pin is directly connected to the circuit board's ground plane, forming a low-impedance return path and reducing ground loop noise. The voltage regulator chip's heat dissipation pads are connected to the ground plane via vias, ensuring effective heat dissipation during chip operation and preventing output voltage fluctuations due to temperature drift. It's important to understand that the selection of the filter capacitor needs to be adjusted based on the noise characteristics of the actual input power supply. For example, when there is severe electromagnetic interference from the external power supply, a common-mode inductor can be added at the input, forming an LC filter network with the filter capacitor to enhance the suppression of common-mode noise.

[0037] During circuit debugging, the ripple voltage at the power supply output was measured using an oscilloscope to verify the effectiveness of the π-type filter circuit. The test results show that the voltage waveform after multi-stage filtering is smooth, and high-frequency glitches are significantly suppressed, meeting the power supply stability requirements for high-precision signal generation. Simultaneously, the impedance matching design of the independent power supply lines 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 terminal is controlled within ±1%, avoiding signal timing deviations caused by power supply fluctuations.

[0038] The advantage of this embodiment lies in the fact that a low-noise power supply system architecture is constructed through standardized design of the power connector, parameter optimization of the multi-stage filtering network, and engineering implementation of an independent power supply strategy. This architecture not only provides a stable operating environment for the MCU control module, but also cuts off the propagation path of noise to the signal generation circuit from the power supply end, laying the energy foundation for the high-precision output of subsequent low-frequency carrier signals and collision simulation signals.

[0039] Example 3: To address the issues of insufficient signal generation accuracy and poor adaptability in existing equipment, this example specifically optimizes the generation paths of low-frequency carrier signals and PWM collision signals. Through MCU timer resource scheduling, dedicated amplifier circuit design, and impedance matching technology, programmable and accurate output of both signals is achieved.

[0040] In the low-frequency carrier signal generation stage, the MCU control module calls its internal high-precision timer and digitally sets the signal frequency, pulse width, and timing through register configuration. Taking a 10kHz square wave signal with a 100ms pulse width as an example, the timer operates in upward counting mode. When the count value reaches the period register setting value (50μs), it triggers a toggle, thereby generating a basic square wave with a 50% duty cycle. This signal is first input to a Darlington amplifier circuit composed of two NPN transistors. The first-stage transistor operates in common-emitter mode to amplify the voltage; the base of the second-stage transistor is connected to the collector of the first-stage transistor, forming a current amplification cascade. The overall amplification factor can reach hFE1×hFE2, improving the signal driving capability and meeting the requirements 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 in parallel with an RC filter circuit. The resistor is used to match the output impedance with the load impedance and reduce signal reflection; the capacitor filters out high-frequency harmonics, ensuring that the rising and falling edges of the output waveform conform to the time-domain characteristics of the square wave signal.

[0041] For PWM collision signals, the duty cycle and period parameters can be remotely configured via host computer software. After receiving the configuration command, the MCU adjusts the timer's compare register value to generate a PWM signal with the corresponding parameters. Taking a typical 50% duty cycle, 2Hz frequency signal as an example, the timer period is set to 500ms, the compare register value is set to 250ms, and pulse generation is achieved by toggling the output pin level. This signal is processed by a common-emitter transistor amplifier circuit, with a current-limiting resistor in series at the base to protect the MCU pins, a pull-up resistor connected to the 5V power supply at the collector, and the emitter grounded, forming a typical signal amplification structure. This converts the 3.3V level signal output by the MCU into a 5V amplitude drive signal, meeting the input level requirements of automotive electronic collision sensors. The amplified signal is transmitted through an independent output interface, which is physically spaced from the low-frequency carrier signal interface to reduce signal crosstalk.

[0042] Furthermore, the bias resistors in the Darlington amplifier circuit utilize precision surface-mount resistors to ensure the transistor operates in the linear amplification region, avoiding saturation distortion. The parameters of the RC filter circuit are designed based on the bandwidth of the target signal. For example, for a 10kHz fundamental signal, the capacitor value must be chosen to have a cutoff frequency significantly higher than 20kHz to preserve the fundamental component and attenuate higher harmonics. It's important to understand that the clock source for the MCU's internal timer can be either an external crystal oscillator or an internal RC oscillator. The former provides higher frequency accuracy and is suitable for testing scenarios with stringent frequency stability requirements; the latter offers a cost advantage and is suitable for applications with moderate accuracy requirements.

[0043] During hardware implementation, the PCB layout of the signal generation circuit follows high-speed signal design principles: the traces from the MCU output pins to the amplifier circuit are kept as short and straight as possible to reduce parasitic capacitance; decoupling capacitors are placed near the power supply pins of the amplifier circuit to suppress the modulation effect of power supply noise on the signal; and standardized connectors, such as BNC interfaces, are used for the output interface to ensure consistent impedance matching. During debugging, the harmonic components of the output signal are detected using a spectrum analyzer to verify the effectiveness of the RC filter circuit. The measured results show that the third harmonic amplitude is reduced by more than 20dB compared to the unfiltered signal, meeting the signal purity requirements for automotive electronic testing.

[0044] This embodiment constructs a high-precision dual-signal generation architecture through precise control of the MCU timer, selection and design of a dedicated amplifier circuit, and matched filtering at the output. This architecture supports both fixed-parameter output of low-frequency carrier signals and flexible configuration of PWM collision signals, adapting to the diverse testing needs of sensors in different vehicle models. Circuit designers can adjust timer parameters, amplifier circuit types, and filter network parameters according to the actual test scenario, achieving a balance between signal accuracy, driving capability, and power consumption, providing a standardized signal input scheme for the reliability verification of automotive electronic control systems.

[0045] Example 4: To address the issues of electromagnetic interference and insufficient parameter configuration flexibility in existing equipment, this example implements anti-interference design and protocol adaptation optimization for the communication interface. Through a three-level signal conditioning circuit, a variable baud rate communication protocol, and electrical isolation measures, reliable transmission and real-time interaction of control commands are achieved.

[0046] Furthermore, the host computer interface adopts 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 consisting of a current-limiting resistor, a Zener diode, and a filter capacitor. The current-limiting resistor is connected in series in the signal input path to limit the input current under abnormal conditions, preventing overcurrent damage to the MCU pins. The Zener diode is connected in parallel between the signal pin and ground to clamp the input voltage amplitude within the safe range that the MCU can withstand, 3.3V±0.3V, to prevent external high-voltage signal impact. The filter capacitor is connected in parallel between the signal pin and ground to form a low-pass filter, filtering out high-frequency noise, such as interference signals above 10MHz, to ensure the integrity of the input signal. The signal after this three-stage processing is connected to the MCU's UART communication pin to realize the level conversion of control commands and noise filtering.

[0047] Furthermore, the communication protocol adopts the UART serial communication standard, supporting an adjustable baud rate within the range of 9600 to 115200. Adaptive matching is achieved through software configuration of the MCU's baud rate register. Control commands sent by the host computer include data frames such as signal output mode (low-frequency carrier / PWM collision), frequency parameters, and indicator light status. The data frame format follows a custom protocol, including a start bit, data bits, parity bit, and stop bit. The parity bit uses XOR check or CRC check to improve the accuracy of data transmission. After receiving the command, the MCU first verifies the parity bit. If the data is correct, it parses the command content, updates the signal generation parameters or indicator light status, and sends a status feedback frame through the reverse UART channel, achieving bidirectional real-time communication.

[0048] Furthermore, to enhance anti-interference capabilities, communication lines are isolated from power lines during PCB layout, and electromagnetic coupling is reduced by surrounding them with ground wires. The connector housing is connected to the circuit board ground layer to form a shielding structure, suppressing external radiated 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 ground loop noise. However, this embodiment is based on a non-isolated design, and the protection circuit composed of passive components meets the immunity requirements of general automotive testing 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 scenarios with severe high-frequency interference, multiple capacitors with different capacitance values ​​can be connected in parallel, such as a combination of 1nF and 100nF, to broaden the filtering frequency band.

[0049] Furthermore, at the software implementation level, the UART communication module adopts an interrupt-driven approach to ensure timely response to host computer commands in a low-power state. The baud rate adaptive function is implemented by sending specific handshake signals. The host computer first sends a fixed-format baud rate probe frame. After receiving the signal, the MCU automatically identifies the baud rate by measuring the level width of the start bit, avoiding the tediousness of manual configuration. During communication, if three consecutive verifications fail, a retransmission mechanism is triggered to ensure reliable reception of critical commands.

[0050] This embodiment constructs a highly reliable human-machine interface through the collaborative design of hardware protection circuits and software communication protocols. This interface can effectively resist external electromagnetic interference, ensure accurate parsing of control commands, and support flexible parameter configuration and status feedback, meeting the remote control needs of automated testing equipment.

[0051] Example 5: To address the issues of low efficiency and redundant hardware architecture in existing vehicle signal analog circuits, this example provides a programmable low-frequency carrier radio frequency signal collaborative control circuit. Through modular design and electrical connection optimization, it achieves organic collaboration among various functional units, ensuring the reliability and flexibility of signal generation, transmission, and status feedback.

[0052] Specifically, the overall circuit architecture includes a power supply module, an MCU control module, a host computer communication module, a low-frequency carrier signal output module, a collision signal simulation module, and a status indicator module. These modules are electrically interconnected via a printed circuit board (PCB) to form a hierarchical hardware system. The power supply module, as the energy supply unit, uses a dedicated power interface to receive external input voltage. The voltage is converted by a voltage regulator chip U2. A high-frequency filter capacitor is connected in parallel at the input to suppress surge interference, and the output uses multiple sets of capacitors of different values ​​to form a π-type filter network, providing a stable 5V voltage with ripple less than 50mV to subsequent modules. This power supply module supplies power to the MCU control module and each functional module through independent traces. The power pin of the MCU chip U9 is directly connected to the high-precision output of the power supply module, ensuring the power supply stability of the digital core unit.

[0053] Furthermore, the MCU control module, as the core of the circuit, integrates high-precision timer resources to provide a timing reference for signal generation. For low-frequency carrier signals, the U9's general-purpose timer (TIMx) generates an initial pulse signal through register configuration, which is output to the low-frequency carrier signal output module via GPIO pins. For PWM collision signals, the U9's advanced control timer (TIM1) supports complementary output and dead-time control, dynamically adjusting the duty cycle and period parameters according to the host computer instructions. It is important to understand that the reset circuit and crystal oscillator circuit of the MCU chip U9 adopt the following design: the reset pin is connected to an RC reset circuit to ensure reliable initialization, and an external 8MHz crystal oscillator works with the internal phase-locked loop (PLL) to provide a 72MHz system clock to meet the requirements of high-precision timing control.

[0054] Furthermore, the host computer communication module enables bidirectional transmission of external control commands. Its input interface employs a single-ended signal design. External signals are processed by a three-stage protection circuit consisting of a current-limiting resistor R1, a Zener diode D1, and a filter capacitor C1 before being connected to the MCU's UART communication pin. The protection circuit clamps the input voltage to a safe range of 3.3V and filters out high-frequency noise, ensuring the integrity of the control commands. The communication protocol uses the UART serial standard and supports adaptive baud rate adjustment. The MCU achieves signal output mode switching, parameter configuration, and status feedback by parsing data frames. For example, upon receiving a mode switching command, U9 sends a control signal to the status indicator module, changing the level state of the indicator light driver circuit.

[0055] Furthermore, the low-frequency carrier signal output module and the collision signal simulation module, as execution units, employ independent signal paths to avoid crosstalk. The former receives a 10kHz square wave signal output from the MCU, which is then amplified by a Darlington amplifier circuit composed of two NPN transistors Q1 and Q2 to enhance the driving capability. The output is connected in series with a matching resistor R2 and in parallel with an RC filter circuit resistor R3 and capacitor C2 to achieve 50Ω impedance matching and high-frequency harmonic suppression. The latter, based on the PWM signal generated by the MCU, converts the 3.3V level to a 5V drive signal through a common-emitter amplifier circuit with transistor Q3, and transmits it to the collision sensor test terminal via an independent output interface. The power supply for both signal amplification circuits is taken from the independent power supply line of the power module, reducing the impact of power fluctuations on the MCU.

[0056] Furthermore, the status indicator module employs a dual-color LED design with independent driving circuits. The red LED corresponds to the collision signal output mode, and the green LED corresponds to the low-frequency carrier signal output mode. The MCU's GPIO pins control the base current of the two indicator lights through current-limiting resistors. When a PWM collision signal is output, U9 sends a high level to the red LED driver circuit, causing the red light to illuminate. When a low-frequency carrier signal is output, the green LED driver circuit is activated, and the green light illuminates. The indicator lights are positioned on the edge of the circuit board for easy visual identification by operators, and the pull-up resistor value of the driver circuit ensures uniform indicator brightness, avoiding identification errors in strong light environments.

[0057] Furthermore, the circuit board layout follows electromagnetic compatibility (EMC) design principles: the power supply module and power amplifier circuit are distributed at the edge of the circuit board, away from the high-frequency digital circuits of the MCU control module; analog and digital signals are routed separately, with different functional areas isolated by grounded copper foil; the output interface uses shielded connectors, with their shells soldered to the circuit board's ground plane to form a complete shielded loop. It is important to understand that the interconnecting signal lines between modules use a differential pair design to reduce common-mode noise interference, while the length of critical signal lines is controlled within a reasonable range to avoid timing deviations caused by transmission delays.

[0058] Furthermore, during hardware implementation, the parameters of key components in each module can be adjusted according to actual needs. For example, the voltage regulator chip can be replaced with a model with higher PSRR to adapt to harsh power supply environments; the transistor selection in the amplifier circuit needs to balance gain and power consumption; and a current feedback resistor can be added to the indicator light driver circuit to improve stability. During debugging, the key node signals of each module are monitored using an oscilloscope to verify the signal generation accuracy, transmission integrity, and status indication response speed, ensuring that the circuit operates stably within its rated operating range.

[0059] This embodiment employs a modular hardware architecture design, clearly defining functional units such as power supply, signal processing, command interaction, signal output, and status feedback. Each module possesses independent operational capabilities while also achieving collaborative operation through an MCU control module. This hierarchical design not only reduces circuit complexity but also facilitates later maintenance and functional expansion, providing a standardized hardware platform for automotive electronic testing equipment.

[0060] Example 6: To address the issue of insufficient power supply stability in the power module leading to abnormal operation of the back-end circuit, this example further refines the hardware architecture of the power module. By clarifying the connection relationships and functional configurations of each component, a reliable power conversion and filtering network is constructed.

[0061] like Figure 2 As shown, the power module uses connectors J3 and J4 as external power input interfaces. Connector J3 is used to connect to the external power supply VCC, and connector J4 is used to ground GND. The two form the electrical circuit for power input. The input terminal IN of the voltage regulator chip U2 is directly connected to connector J3. Its function is to convert the external input voltage into a stable 5V DC output. Multiple sets of filter capacitors are connected in parallel between the output terminal OUT and connector J4. Specifically, capacitors CB6 and CB7 are connected in parallel between connectors J3 and J4 to form an input stage high-frequency noise suppression network, which can absorb surge voltage and high-frequency interference introduced by the external power supply. Capacitors CB8, CB9, and C5 are connected in parallel between the output terminal OUT of the voltage regulator chip U2 and connector J4. The combination of capacitors with different capacitance values ​​achieves full-band filtering. Among them, electrolytic capacitors are responsible for low-frequency ripple filtering, ceramic capacitors handle high-frequency noise, and tantalum capacitors improve transient response capability, together ensuring the purity of the output voltage. The output terminal OUT of the voltage regulator chip U2 is electrically connected to pin 9 of the MCU chip U9 via an independent power supply line. This power supply line adopts a widened trace design to reduce line impedance, thereby providing a stable operating voltage for the MCU.

[0062] Furthermore, connector J3 employs a power interface with a mechanical locking structure. This design ensures electrical connection stability when an external power supply is connected, preventing voltage fluctuations caused by poor contact. The voltage regulator chip U2 must meet low dropout (LDO) characteristics and high power supply rejection ratio (PSRR) requirements to reduce the impact of input voltage fluctuations on the output. It is important to understand that the capacitance values ​​of capacitors CB6 and CB7 must be configured according to the noise characteristics of the external power supply; typically, ceramic capacitors with excellent high-frequency characteristics are selected. Meanwhile, capacitors CB8 and CB9 at the output end can be a combination of electrolytic and ceramic capacitors, forming a π-type filter structure to effectively attenuate noise components in different frequency bands.

[0063] Furthermore, regarding the circuit board layout, the voltage regulator chip U2 should be placed close to connector J3 to shorten the input power line length and reduce line impedance. Its heat dissipation pad is connected to the ground plane connector J4 through a via to ensure effective heat dissipation during chip operation and avoid output voltage drift caused by temperature changes. The output capacitors CB8, CB9, and C5 should be mounted close to the OUT pin of U2 to reduce the impact of parasitic inductance on the filtering effect. Simultaneously, the connection between the power supply pin of the MCU chip U9 and the power module output should avoid crossing high-frequency signal traces to prevent noise interference introduced by electromagnetic coupling.

[0064] In practical applications, if severe common-mode interference exists in the external power supply, a common-mode inductor can be added between the input terminals IN of J3 and U2 to form an LC filter structure in conjunction with the existing capacitor filter network, thereby enhancing the suppression of common-mode noise. This embodiment constructs a complete power supply link, including input protection, voltage regulation, and multi-stage filtering, through explicit component connections and parameter configurations, providing a stable 5V operating voltage to the downstream circuitry and meeting the power quality requirements of the MCU control module and various functional units. Circuit designers can adjust the capacitor values ​​and voltage regulator chip models according to the characteristics of the actual input power supply, ensuring power supply stability while also considering the rationality of the circuit board layout and manufacturing costs.

[0065] The advantage of this embodiment is that by defining the connection relationships and functional divisions of the various components of the power module, a hierarchical power processing architecture is formed. From the mechanical stability design of the input interface to the characteristic selection of the voltage regulator chip, and then to the frequency band coverage of the multi-level filter network, the power stability problem is systematically solved, laying an energy foundation for the reliable operation of the entire circuit system.

[0066] Example 7: To solve the problem of signal distortion or misinterpretation of control commands caused by external interference during the communication process between the host computer and the host computer, this example further constructs the hardware circuit of the host computer communication module. Through the reasonable configuration of signal conditioning elements, reliable reception of external trigger signals and noise filtering are achieved.

[0067] like Figure 2As shown, the host computer communication module uses interface J2 as its external signal input port. This interface receives trigger input signals sent by the host computer and is connected to pin 11 (the communication receive pin) of the MCU chip U9 via resistor R6. In the signal transmission path, resistor R2, diode D1, and capacitor C3 are connected in parallel between pin 11 of U9 and ground, forming a three-stage protection circuit: resistor R2 acts as a current-limiting resistor connected in series in the signal path, limiting the input current under abnormal conditions and preventing overcurrent damage to the MCU pins; diode D1 is a Schottky diode with its cathode connected to the 3.3V power supply and its anode grounded, clamping 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 ground, filtering out high-frequency noise components and ensuring the integrity of the input signal. Furthermore, capacitor C2 is connected in parallel between the host computer interface J2 and ground, forming an input-stage low-pass filter to further attenuate high-frequency interference signals coupled during transmission.

[0068] Furthermore, the host computer interface J2 uses a standardized connector, whose mechanical structure ensures a reliable connection with external cables and reduces the introduction of contact noise. The resistance value of resistor R6 must balance signal attenuation and driving capability; typically, a precision resistor meeting the circuit characteristics is selected to avoid signal attenuation or overcurrent risks due to improper resistance values. It is important to understand that the clamping voltage of diode D1 must match the withstand voltage rating of the MCU pin to ensure effective protection of the internal circuitry in the event of abnormal external voltage. The capacitance values ​​of capacitors C2 and C3 need to be adjusted according to the target noise frequency to effectively filter out interference signals in specific frequency bands.

[0069] In the PCB layout design, the host computer interface J2 should be kept away from power modules and high-frequency signal traces to reduce electromagnetic coupling interference. Signal lines connecting J2 to MCU pins should be short and straight to avoid parasitic capacitance introduced by excessively long lines affecting signal transmission speed. Protection circuit components should be placed close to the MCU pins to ensure noise is effectively suppressed before entering the internal circuitry. Simultaneously, the ground terminal of the communication module should be directly connected to the ground plane of the circuit board, forming a low-impedance return path to reduce the impact of ground loop noise on the signal.

[0070] In practical applications, the host computer communication module supports the UART serial communication protocol, and variable baud rate communication is achieved through software configuration of the MCU's baud rate register. When an external trigger signal is input via J2, it is first initially filtered by capacitor C2, then processed by a protection circuit consisting of resistor R2, diode D1, and capacitor C3, and finally transmitted to pin 11 of U9. After receiving the signal, the MCU verifies the integrity of the data frame through an internal verification mechanism to ensure accurate parsing of control commands.

[0071] This embodiment clarifies the component composition and connection relationship of the host computer communication module, constructs a complete input link including signal filtering, overvoltage protection and noise suppression, effectively improves the anti-interference capability of the communication interface, ensures reliable transmission of external trigger signals and correct response of the MCU, and provides a stable hardware foundation for real-time interaction between the host computer and the circuit system.

[0072] Example 8: To address the issues of insufficient driving capability and waveform distortion in low-frequency carrier signal output, this example further designs the circuit structure of the low-frequency carrier signal output module. Through the coordinated configuration of multi-stage amplifier circuits and impedance matching networks, high-precision output of fixed-frequency signals is achieved.

[0073] like Figure 2 As shown, the signal path of the low-frequency carrier signal output module begins at pin 12 (SDW_CLK) of the MCU chip U9. This pin outputs the initial low-frequency carrier signal, which is then connected to the gate of transistor Q2 after passing through a voltage divider network composed of resistors R4 and R7. Transistor Q2 is an N-type field-effect transistor with its emitter grounded. Its collector is connected to a 5V regulated power supply through resistors R1 and R3, forming the first-stage amplifier circuit to amplify the voltage of the MCU output signal. Transistor Q1 is a P-type field-effect transistor with its gate connected between resistors R1 and R3, its emitter connected to a 5V power supply, and its collector connected to output connector J1 through resistor R5, forming the second-stage amplifier circuit. This second-stage amplifier circuit complements transistor Q2, enhancing the signal driving capability. An RC filter circuit composed of resistor R8 and capacitor C1 is connected in parallel at the output terminal to filter out high-frequency harmonics, ensuring the purity of the output waveform. Resistor R9 is connected between J1 and ground to match the output impedance with the load, reducing signal reflection.

[0074] Furthermore, the voltage division ratio of resistors R4 and R7 is designed based on the output level of the MCU pin and the turn-on voltage of transistor Q2 to ensure that transistor Q2 operates in the linear amplification region and avoids saturation distortion. The values ​​of resistors R1 and R3 need to consider both the collector current of transistor Q2 and the gate drive voltage of transistor Q1. Through proper configuration, the two-stage amplifier circuit forms a gain cascade to meet the requirements of driving long-distance transmission cables or high input impedance loads. It is important to understand that the selection of transistors Q1 and Q2 must consider transconductance parameters and voltage ratings. Low-noise MOSFETs are typically selected to reduce noise components introduced during amplification.

[0075] During signal transmission, 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 high-frequency oscillations on the rising and falling edges, ensuring that the output waveform conforms to the time-domain characteristics of a square wave signal. Resistor R9 serves as a matching resistor, and its resistance value is set according to the target load impedance to achieve maximum power transmission of the signal.

[0076] When laying out the circuit board, the traces from the MCU pins to the amplifier circuit should be as short and straight as possible to reduce the impact of parasitic inductance on the signal edges; the heat dissipation pads of transistors Q1 and Q2 need to be connected to the ground plane to avoid operating point drift due to temperature rise; the output connector J1 adopts a standardized interface, and its internal impedance is matched with the external test equipment to ensure the consistency of signal transmission.

[0077] In practical applications, if the target load has specific requirements for signal amplitude, the power supply bias of the amplifier circuit can be changed by adjusting the values ​​of resistors R1 and R3, thereby adjusting the voltage amplitude of the output signal. The RC parameters of the filter circuit need to be designed according to the frequency of the low-frequency carrier signal to preserve the fundamental component and attenuate higher harmonics.

[0078] This embodiment clarifies the component connections and circuit architecture of the low-frequency carrier signal output module, constructing a complete signal path including voltage divider bias, two-stage amplification, and impedance matching. This effectively improves the signal driving capability and waveform quality, ensuring high-precision output of low-frequency carrier signals with fixed frequency and timing, and meeting the requirements of relevant tests for the signal source.

[0079] Example 9: To address the issue of hardware consistency between collision signal simulation and status indication functions, this example further constructs the circuit structure of the collision signal simulation module and the status indication module. By clearly defining the component connections and signal paths, reliable output of PWM collision signals and intuitive feedback of operating status are achieved.

[0080] like Figure 2 As shown, in the collision signal simulation module, pin 14 of the MCU chip U9 outputs a PWM collision signal, which is connected to the gate of transistor Q3 after passing through a voltage divider network composed of resistors R10 and R11. Transistor Q3 is an N-type field-effect transistor with its emitter grounded and its collector directly connected to output connector J5, forming a common-source amplifier circuit. This circuit converts the 3.3V level signal output by the MCU into a 5V amplitude drive 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 surges, while resistor R11 is used to set the quiescent operating point of transistor Q3, ensuring that it operates in the linear amplification region and avoiding signal distortion.

[0081] Furthermore, the status indicator module adopts a dual-color indicator light design. Pin 19 of the MCU (LED_R) is directly connected to the red indicator light, and pin 20 (LED_G) is connected to a 5V regulated power supply via resistor R15, and then connected to the green indicator light. The red indicator light is used to indicate the collision signal output status. When U9 outputs a PWM collision signal, the LED_R pin outputs a low level, causing the red indicator light to conduct and illuminate. The green indicator light indicates the normal signal output status. The LED_G pin is pulled up to 5V through resistor R15. When a low-frequency carrier signal is output, this pin remains at a high level, and the green indicator light illuminates. Resistor R15 acts as a current-limiting resistor, limiting the operating current of the indicator light to ensure uniform brightness and extend its service life.

[0082] Furthermore, the selection of transistor Q3 needs to consider switching speed and current drive capability to ensure fast response and accurate amplification of the PWM signal. Connector J5 employs a mis-mating prevention design, matching the input interface of the collision sensor to avoid circuit damage caused by incorrect connections. The status indicator lights are located on the front panel of the circuit board for easy visual identification by operators, and the indicator light drive circuit and signal amplification circuit are independent of each other on the power supply circuit, reducing electromagnetic interference between them.

[0083] It's important to understand that the power supply for the amplification circuit of the collision signal simulation module is taken from the independent power supply line of the power module, physically separated from the power path of the MCU control module. This avoids current fluctuations caused by PWM signal switching affecting the stable operation of the MCU. The indicator pins of the status indicator module are directly controlled via GPIO ports. The MCU can switch the indicator status in real time according to the current signal output mode, achieving visual feedback for human-machine interaction.

[0084] When laying out the PCB, the output lines of the collision signal simulation module and the drive lines of the status indicator lights should be kept away from high-frequency digital signal lines to reduce crosstalk. The gate trace of transistor Q3 needs impedance control to avoid parasitic capacitance introduced by excessively long traces, which could cause signal edge delay. The installation position of the indicator lights should consider the viewing angle to ensure clear identification of their status under different lighting conditions.

[0085] In practical applications, adjusting the brightness of the indicator light can be achieved by changing the resistance value of resistor R15. If the input impedance of the collision sensor is high, a matching resistor can be connected in parallel at the output of J5 to improve the stability of signal transmission. The control logic of the status indicator module works in conjunction with the signal generation module. When the MCU receives a mode switching command from the host computer, it synchronously updates the indicator light status to ensure consistency between hardware indication and software configuration.

[0086] This embodiment clarifies the hardware implementation of the PWM signal amplification path and status feedback mechanism through the detailed circuit design of the collision signal simulation module and the status indication module, ensuring reliable output and level conversion of the collision signal. At the same time, the dual-color indicator light realizes the intuitive display of the working status, providing convenience for the operation and maintenance of related equipment.

[0087] Example 10: To address the issues of fragmented functional modules, low efficiency of collaborative control, and insufficient adaptability in existing signal generation equipment, this example further constructs an overall architecture for a programmable low-frequency carrier radio frequency signal generation system. Through modular division and systematic integration of functional units, collaborative work and parameter linkage between modules are achieved, meeting the signal generation requirements under complex testing scenarios.

[0088] The generation system uses the MCU chip U9 as the control center, with built-in signal generation algorithms and communication protocol stacks. It achieves real-time adjustment of signal parameters through preset register configurations. Specifically, pin 9 of the MCU chip U9 connects to the 5V output of the power supply unit to obtain a stable operating voltage; pin 11 receives instruction data sent by external devices through the host computer communication module, and after internal parsing, generates corresponding control signals, which are transmitted to the signal generation unit and the status indication module respectively. Regarding signal parameter configuration, the MCU chip U9 outputs a low-frequency carrier signal clock control signal through pin 12, and an adjustable duty cycle and frequency signal for the PWM collision signal through pin 14. The timing relationship of these two types of signals is precisely synchronized by the internal timer module to ensure the phase consistency of the output signals. It is important to understand that the control unit's software architecture supports modular programming, allowing users to customize signal waveform parameters through the host computer software. After instruction parsing, the internal register configuration of the MCU is updated in real time, thereby achieving programmability in signal generation.

[0089] Furthermore, the power supply unit integrates multi-stage filtering and voltage regulation circuits. Its input terminal is connected to an external power supply VCC via connector J3. After being converted to a stable 5V voltage by the voltage regulator chip U2, it supplies power to the control unit, signal generation unit, and human-machine interface unit through independent power supply lines. The input stage of the power supply unit is equipped with capacitors CB6 and CB7 to suppress high-frequency noise, while the output stage uses capacitors CB8, CB9, and C5 to form a π-type filter network, reducing the impact of power supply ripple on signal generation accuracy. Notably, a single-point grounding design is used between the power supply unit and the signal generation unit to avoid mutual interference between ground currents of different functional modules, ensuring separation of the ground planes for analog and digital signals, and improving the system's electromagnetic compatibility (EMC).

[0090] Furthermore, the signal generation unit includes a low-frequency carrier signal output module and a collision signal simulation module, which, under the coordination of the control unit, achieve differentiated signal output. The low-frequency carrier signal output module uses pin 12 of the MCU chip U9 as the signal source. After voltage division by resistors R4 and R7, it drives transistor Q2. A complementary amplifier circuit composed of transistors Q1 and Q2 enhances the signal driving capability, and finally, a low-frequency carrier signal with a fixed frequency timing is output through connector J1. Resistor R8 and capacitor C1 in this module form an output filter network to suppress high-frequency harmonic components and ensure the purity of the signal waveform. 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 configurable PWM signal through pin 14 of the MCU chip U9. After voltage division by resistors R10 and R11, it controls the conduction state of transistor Q3. A 5V amplitude collision signal conforming to automotive electronics testing standards is output through connector J5. Its duty cycle and frequency parameters can be modified in real time via upper computer commands to meet the signal simulation requirements under different test conditions.

[0091] Furthermore, the human-machine interface unit establishes a two-way interactive channel between the system and external devices and operators. The host computer communication module receives external control commands through the host computer interface J2. After interference is filtered out by a signal conditioning circuit composed of resistors R6 and R2, diode D1, capacitors C2 and C3, the commands are transmitted to pin 11 of the MCU chip U9. It supports multiple serial communication protocols such as UART and SPI and is compatible with the control software of mainstream test equipment. The status indicator module adopts a dual-color indicator design. The red indicator is directly connected to pin 19 of the MCU (LED_R) to indicate the collision signal output status. When a PWM collision signal is generated, this pin outputs a low level to illuminate the red light. The green indicator is pulled up to 5V through resistor R15 and then connected to pin 20 of the MCU (LED_G) to indicate the normal signal output status. The green light remains constantly lit when the low-frequency carrier signal is working. Both types of indicator lights are located on the front panel of the system, using high-brightness surface-mount LEDs and a transparent light guide cover to achieve visual feedback of the status, facilitating real-time monitoring of the equipment's operating mode by operators.

[0092] Furthermore, the system hardware architecture employs 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 shielding layers to reduce inter-layer electromagnetic coupling. Connectors J1 and J5, among other signal output interfaces, are shielded with metal shells and grounding springs to achieve 360° electromagnetic shielding, reducing the impact of external interference on the output signals. The peripheral circuitry of the MCU chip U9 is equipped with decoupling capacitors, placed close to the chip's power pins to suppress high-frequency noise interference with the control logic. It is important to understand that the system software design includes a fault diagnosis mechanism. When abnormal power supply voltage or signal output exceeding limits is detected, a warning signal is issued through a combination of flashing status indicator lights, and an error code is sent to the host computer, improving the reliability and maintainability of the equipment.

[0093] In practical applications, this system can preset multiple signal parameter combinations via host computer software, supporting one-click switching between different test modes to meet the collaborative testing needs of low-frequency carrier signals and collision simulation signals in fields such as automotive electronics and IoT devices. The output connector of the signal generation unit adopts a standardized interface, compatible with industry-standard test fixtures, reducing signal loss caused by adapter conversion. The power supply unit supports a wide voltage input range; by changing the model of the voltage regulator chip U2, it can be adapted to different external power supplies such as 12V and 24V, improving the environmental adaptability of the equipment.

[0094] The advantage of this embodiment lies in its organic integration of the control unit, power supply unit, signal generation unit, and human-machine interface unit, which constructs a functionally modular and programmable signal generation system architecture. Each unit possesses independent hardware design logic and achieves coordinated signal and energy transmission through standardized interfaces. This ensures high-precision generation of low-frequency carrier signals and PWM collision signals, flexible parameter configuration, and real-time status feedback, providing a systematic solution for equipment testing in complex electromagnetic environments. Circuit designers can adjust the component parameters and interface forms of each unit according to the target application scenario, achieving a balance between functional expansion and cost optimization while maintaining the integrity of the system architecture.

[0095] Although the present invention has been specifically described above with reference to preferred embodiments, it should be understood that the present invention is not limited to the embodiments described above. Various modifications and variations can be made by those skilled in the art without departing from the spirit of the present invention, and such modifications and variations should fall within the scope defined by the appended claims and their equivalents.

Claims

1. A programmable low-frequency carrier radio frequency signal cooperative control method, characterized in that, Includes the following steps: The input voltage is connected through an external power interface, converted into a stable 5V operating voltage by a voltage regulator chip, and then filtered out by multiple parallel filter capacitors to provide power to the MCU control module and various functional modules. The MCU control module generates two types of signals: First, a low-frequency carrier signal is generated according to a preset frequency and timing, driven by a two-stage transistor amplifier circuit, and output to an external device through an output interface; Second, a specified PWM signal is generated according to the characteristic parameters of the vehicle collision signal, and output through an independent interface after passing through a transistor drive circuit, for simulating collision conditions. The external trigger input signal is received through the host computer communication module. After being processed by the signal conditioning circuit for current limiting, clamping and filtering, it is transmitted to the MCU control module for external devices to control the circuit's working mode and configure parameters. The MCU control module drives a dual-color indicator light according to the current working state: the red indicator light is lit when a PWM collision signal is output, and the green indicator light is lit when a normal low-frequency carrier signal is output, for quick identification of the working mode.

2. The programmable low-frequency carrier radio frequency signal cooperative control method as described in claim 1, characterized in that, The external power supply is connected through a connector, and the voltage is converted by a voltage regulator chip. A high-frequency filter capacitor is connected in parallel at the input to suppress surge interference. Multiple sets of capacitors with different capacitance values ​​are connected in parallel at the output to form a π-type filter circuit, and the output voltage ripple is less than 50mV. The stabilized 5V power supply directly powers the MCU chip and supplies power to the signal amplification circuit and indicator module through an independent power line to avoid power noise coupling between different modules.

3. The programmable low-frequency carrier radio frequency signal cooperative control method as described in claim 1, characterized in that, The frequency, pulse width, and output timing of the low-frequency carrier signal are configured by the internal timer of the MCU control module. The output is a square wave signal with a frequency of 10KHz and a pulse width of 100ms. The driving capability is enhanced by a Darlington amplifier circuit composed of two NPN transistors. The output terminal is connected in series with a matching resistor and in parallel with an RC filter circuit to suppress high-frequency harmonics and achieve 50Ω impedance matching. The duty cycle and period parameters of the PWM collision signal can be configured by the host computer software to generate a pulse signal with a 50% duty cycle and a 2Hz frequency. After passing through the transistor common emitter amplifier circuit, the signal is output through the interface to meet the signal simulation requirements of the automotive electronic collision sensor.

4. The programmable low-frequency carrier radio frequency signal cooperative control method as described in claim 1, characterized in that, The host computer's interface uses a single-ended signal input method. The input signal is processed by a protection circuit consisting of a current-limiting resistor, a Zener diode, and a filter capacitor to clamp the voltage amplitude to a safe range of 3.3V. After filtering out high-frequency noise, it is connected to the MCU's communication pin. The communication protocol uses UART serial communication and supports an adjustable baud rate of 9600 to 115200 to enable remote configuration and real-time monitoring of signal output mode, frequency parameters and indicator status by an external host computer.

5. A programmable low-frequency carrier radio frequency signal cooperative control circuit, used to execute the programmable low-frequency carrier radio frequency signal cooperative control method as described in any one of claims 1-4, characterized in that, include: The power module is used to provide a stable operating voltage; The MCU control module, including the MCU chip U9, is used to generate low-frequency carrier signals, PWM collision signals, and control status indicators. The host computer communication module is used to realize signal interaction with an external host computer; Low-frequency carrier signal output module, used to output low-frequency carrier signals with fixed frequency and timing; The collision signal simulation module is used to output a specified PWM signal to simulate a vehicle collision signal; The status indicator module is used to display the circuit's operating status via indicator lights; The power supply module is electrically connected to the MCU control module, and the host computer communication module, low-frequency carrier signal output module, collision signal simulation module and status indication module are respectively electrically connected to the MCU control module.

6. The programmable low-frequency carrier radio frequency signal coordinated control circuit as described in claim 5, characterized in that, The power module includes: Connector J3 is used to connect to an external power supply VCC; Connector J4, ground (GND); The voltage regulator chip U2 has its input terminal IN connected to the connector J3, and its output terminal OUT outputs a 5V regulated power supply. Capacitors CB6 and CB7 are connected in parallel between connectors J3 and J4; Capacitors CB8, CB9, and C5 are connected in parallel between the output terminal OUT of the voltage regulator chip U2 and connector J4. The output terminal OUT of the voltage regulator chip U2 is electrically connected to pin 9 of the MCU chip U9.

7. The programmable low-frequency carrier radio frequency signal coordinated control circuit as described in claim 5, characterized in that, The host computer communication module includes: The host computer interface J2 is connected to pin 11 of the MCU chip U9 via resistor R6; Resistor R2, diode D1, and capacitor C3 are connected in parallel between pin 11 of the MCU chip U9 and ground; Capacitor C2 is connected in parallel between the host computer interface J2 and ground; The host computer interface J2 is used to receive trigger input signals from an external host computer and transmit them to the MCU chip U9.

8. The programmable low-frequency carrier radio frequency signal cooperative control circuit as described in claim 5, characterized in that, The low-frequency carrier signal output module includes: Resistors R4 and R7 are connected in series, with one end grounded and the other end connected to pin 12 (SDW_CLK) of the MCU chip U9. Transistor Q2 has its gate connected between resistors R4 and R7, its emitter grounded, and its collector connected to a 5V regulated power supply through resistors R1 and R3. Transistor Q1 has its gate connected between resistors R1 and R3, its emitter connected to a 5V regulated power supply, and its collector connected to connector J1 through resistor R5. Resistor R8 and capacitor C1 are connected in parallel between the collector of transistor Q1 and ground; Resistor R9 is connected between connector J1 and ground; The connector J1 is used to output the low-frequency carrier signal generated by the MCU chip U9.

9. The programmable low-frequency carrier radio frequency signal coordinated control circuit as described in claim 5, characterized in that, The collision signal simulation module and the status indication module include: In the collision signal simulation module, resistors R10 and R11 are connected in series, with one end grounded and the other end connected to pin 14 of the MCU chip U9. The gate of transistor Q3 is connected between resistors R10 and R11, the emitter is grounded, and the collector is connected to connector J5. Connector J5 is used to output PWM collision signals. In the status indication module, pin 19 (LED_R) of the MCU chip U9 is connected to a red indicator light, and pin 20 (LED_G) is connected to a 5V regulated power supply through resistor R15 and then connected to a green light. The red indicator light is used to indicate the collision signal output status, and the green light is used to indicate the normal signal output status.

10. A programmable low-frequency carrier radio frequency signal generation system, integrating the programmable low-frequency carrier radio frequency signal cooperative control circuit as described in any one of claims 5-9, characterized in that, include: The control unit, including the MCU chip U9, is used to execute signal generation algorithms, parse host computer instructions and control status indications, and configure and control the parameters and timing of low-frequency carrier signals and PWM collision signals. The power supply unit, including the power module, is used to convert the external input power into a stable 5V voltage, suppress power supply noise through a multi-stage filtering circuit, and provide clean power supply. The signal generation unit includes a low-frequency carrier signal output module and a collision signal simulation module, which are used to generate a low-frequency carrier signal with fixed frequency timing and a PWM collision signal with configurable parameters, respectively, to meet the signal output requirements of different test scenarios. The human-computer interaction unit includes a host computer communication module and a status indication module. It realizes the input of control commands from external devices through the host computer interface and realizes the visual feedback of working status through dual-color indicator lights.

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