Liquid leakage detection device and detection method thereof

Abstract

The present invention discloses a liquid leakage detection device, comprising: a power supply circuit, and a detection control circuit, a detection signal generating circuit, and an echo signal acquisition circuit electrically connected to the power supply circuit; the detection control circuit includes a detection control chip, which is connected to the input end of the detection signal generating circuit and provides a pulse signal to the detection signal generating circuit to trigger an optical signal generator in the detection signal generating circuit to perform detection; the detection control chip is connected to an echo signal acquisition circuit, the signal acquisition end of the echo signal acquisition circuit corresponds to the optical signal generator, and the echo signal acquisition circuit acquires the optical signal emitted by the optical signal generator after passing through the detection area; the output end of the echo signal acquisition circuit is connected to the signal sampling end of the detection control chip; the detection control chip is also connected to an alarm circuit for indicating the detection status. The present invention discloses a liquid leakage detection device capable of non-contact detection and a detection method thereof.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid leakage detection, and in particular to a liquid leakage detection device and a detection method thereof. Background Art

[0002] In existing technologies, fluid monitoring is required in high-sensitivity scenarios such as semiconductor wafer manufacturing, biopharmaceuticals, and sterile food production. However, there are the following technical bottlenecks in achieving fluid detection in high-sensitivity scenarios: micro-contamination control (≤Class10), μW-level ultra-low power operation, miniaturized packaging, and corrosion resistance detection (tolerance to pH1-13).

[0003] The above technical bottleneck is particularly prominent in the detection of micro-leakage (<0.1μL / min) of transparent / low surface tension media such as pure water / chemical mechanical polishing liquid (CMP) in closed equipment during chip manufacturing.

[0004] Therefore, there is an urgent need to develop a liquid leakage detection device and a detection method thereof that can achieve non-contact detection through a composite sensing architecture. Summary of the Invention

[0005] The present invention overcomes the deficiencies of the prior art and provides a liquid leakage detection device and a detection method thereof capable of realizing non-contact detection.

[0006] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a liquid leakage detection device, comprising: a power supply circuit, and a detection control circuit, a detection signal generating circuit, an echo signal acquisition circuit, and an alarm circuit electrically connected to the power supply circuit; the detection control circuit includes a detection control chip, the detection control chip is connected to the input end of the detection signal generating circuit, and provides a pulse signal to the detection signal generating circuit, which is used to trigger the optical signal generator in the detection signal generating circuit for detection; the detection control chip is connected to the echo signal acquisition circuit, the signal acquisition end of the echo signal acquisition circuit corresponds to the optical signal generator, and the optical signal emitted by the optical signal generator after passing through the detection area is collected by the echo signal acquisition circuit, and the output end of the echo signal acquisition circuit is connected to the signal sampling end of the detection control chip; the detection control chip is also connected to a warning circuit for indicating the detection status.

[0007] In a preferred embodiment of the present invention, the optical signal generator is located on one side of the detection area, the signal acquisition end is located on the other side of the detection area, and a gradient refraction optical path is provided in the detection area. The optical signal generator emits an optical signal and enters from the gradient refraction optical path, and is received by the signal acquisition end after passing through the detection area.

[0008] In a preferred embodiment of the present invention, the power supply circuit includes a reference voltage circuit and a voltage modulation circuit connected to the reference voltage circuit, the voltage modulation circuit outputs a DVCC terminal, and the DVCC terminal is a step-down output terminal;

[0009] The echo signal acquisition circuit includes a signal receiving processor corresponding to the optical signal generator, wherein the VCC pin of the signal receiving processor is connected to the DVCC terminal through a resistor R1, the VCC pin of the signal receiving processor is grounded at a common point with the GND pin of the signal receiving processor through a capacitor C1, the OUT pin of the signal receiving processor is connected to the DVCC terminal through a resistor R2, and the OUT pin of the signal receiving processor is connected to one of the sampling terminals of the detection control chip as a PWMOUT terminal.

[0010] In a preferred embodiment of the present invention, the optical signal generator adopts an infrared emitter, the inverting end of the infrared emitter is connected to one of the control signal output ends of the detection control chip as the LEDOUT end, the non-phase end of the infrared emitter is connected to one end of the resistor R4, the other end of the resistor R4 is connected to one end of the adjustment potentiometer R5, the other end of the adjustment potentiometer R5 is grounded; the adjustment end of the adjustment potentiometer R5 is connected to the DVCC end.

[0011] In a preferred embodiment of the present invention, the detection control circuit is also connected to a signal alarm output circuit, which includes a transistor Q1, the base of the transistor Q1 is connected to the SINOUT pin of the detection control chip through a voltage divider resistor R14, the base of the transistor Q1 is also grounded through a pull-down resistor R12, the collector of the transistor Q1 is connected to one end of the resistor R11, and the other end of the resistor R11 leads to the LIMOUT node to provide an alarm signal to the external device; the emitter of the transistor Q1 is grounded.

[0012] In a preferred embodiment of the present invention, the reference voltage circuit includes a power supply VCC, the output end of the power supply VCC is connected to the anode of the diode D1, and the cathode of the diode D1 is connected to the VIN node through the resistor R3;

[0013] The voltage modulation circuit includes a step-down chip U2, the VIN pin of the step-down chip U2 is connected to the VIN node, and the VIN pin is grounded through the parallel filter capacitor C4 and the filter capacitor C5, the SW pin of the step-down chip U2 is connected to the BOOT pin through the bootstrap capacitor C2, the SW pin of the step-down chip U2 is connected to one end of the inductor L1, the other end of the inductor L1 is the DVCC end, and the DVCC end is the step-down output end, the FB pin of the step-down chip U2 is connected to the DVCC end through the resistor R6, the FB pin of the step-down chip U2 is connected to one end of the resistor R8, the other end of the resistor R8 is connected to the DVCC end through the filter capacitor C3, the connection node between the resistor R8 and the filter capacitor C3 is grounded, and a freewheeling diode D2 is connected in parallel at both ends of the filter capacitor C3, and the inverting end of the freewheeling diode D2 is connected to the DVCC end, and the positive end of the freewheeling diode D2 is grounded.

[0014] In a preferred embodiment of the present invention, the reset pin of the detection control chip of the detection control circuit is led out in two ways, one of which is connected to the DVCC terminal through the pull-up resistor R7, and the other is grounded through the reset capacitor C6. The BOOT pin of the detection control chip is grounded through the resistor R9, and the VDD pin of the detection control chip is led out in two ways, one of which is grounded through the capacitor C7, and the other is connected to the DVCC terminal.

[0015] In a preferred embodiment of the present invention, the warning circuit includes a plurality of warning branches with warning lights of different colors, one end of the warning lights of the plurality of warning branches is connected to the warning signal output terminal of the detection control chip, and the other end of the warning lights is connected to the DVCC terminal;

[0016] And / or, the gradient refraction optical path includes a refractive prism 1 sunk into the detection area, and a refractive prism 2 located on the light incident side of the trapezoidal prism. The light of the optical signal generator is introduced from one side of the refractive prism 2, and then output from the other side of the refractive prism 2 and enter the incident side of the refractive prism 1. The detection light forms a U-shaped detection optical path in the detection area through the refractive prism 1 and is sent back to the signal collection end.

[0017] In a preferred embodiment of the present invention, the SWDIO pin and the SWCLK pin of the detection control chip of the detection control circuit are connected to the data transmission chip;

[0018] And / or, the detection control chip is further connected to a power amplifier circuit, the power amplifier circuit includes a power amplifier chip, the non-phase input terminal of the power amplifier chip is connected to the PGA-INP pin of the detection control chip, and the output terminal of the power amplifier chip is connected to the PGA-OUT pin of the detection control chip; the inverting input terminal of the power amplifier chip is connected to the output terminal of the power amplifier chip; or, the detection control chip has a built-in power amplification instruction;

[0019] And / or, the detection control chip has built-in echo signal processing instructions.

[0020] In a preferred embodiment of the present invention, a detection method of a liquid leakage detection device is implemented using the liquid leakage detection device and comprises the following steps:

[0021] Provide working power to the detection signal generating circuit, echo signal collecting circuit and warning circuit through the power supply circuit;

[0022] The detection control chip of the detection control circuit provides a pulse signal. The pulse signal is amplified and shaped by a virtual power amplification module established by the power amplification instruction built into the detection control chip or a power amplification circuit connected to the power amplification chip, and then provided to the detection signal generating circuit. The detection signal generating circuit obtains the amplified and shaped pulse signal, and drives the optical signal generator in the detection signal generating circuit through the amplified and shaped pulse signal. The optical signal generator irradiates the detection light on the detection monitoring area. After the detection light passes through the detection monitoring area, the detection light passing through the detection monitoring area is collected by the receiver in the echo signal acquisition circuit. The echo signal acquisition circuit converts the obtained detection light signal into an electrical signal as an echo signal and feeds it back to the detection control chip; the virtual echo signal processing module established by the echo signal processing instruction in the detection control chip processes the signal to obtain the detection result.

[0023] The present invention solves the defects existing in the technical background, and the beneficial technical effects of the present invention are:

[0024] The present invention provides a liquid leakage detection device and a detection method capable of realizing non-contact detection.

[0025] The present invention realizes the capture of leakage at hidden sites through the design of gradient refractive index light path. Its non-contact detection mode avoids the blind spots of manual inspection, and its modular design supports plug-and-play integration. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention will be further described below with reference to the accompanying drawings and examples.

[0027] Figure 1 This is a working flow diagram of a liquid leakage detection device according to a preferred embodiment of the present invention;

[0028] Figure 2 This is a control flow chart of a liquid leakage detection device according to a preferred embodiment of the present invention;

[0029] Figure 3 1 is a circuit diagram of a liquid leakage detection device according to a preferred embodiment of the present invention;

[0030] Figure 4 1 is a schematic diagram of a power amplification circuit of a liquid leakage detection device according to a preferred embodiment of the present invention;

[0031] Figure 5 This is a comparison diagram of wavelength and receiving intensity of a liquid leakage detection device according to a preferred embodiment of the present invention;

[0032] Figure 6 This is a comparison diagram of frequency and receiving intensity of a liquid leakage detection device according to a preferred embodiment of the present invention;

[0033] Figure 7 This is a test of a liquid leakage detection device according to a preferred embodiment of the present invention. Figure 1 ;

[0034] Figure 8 This is a test of a liquid leakage detection device according to a preferred embodiment of the present invention. Figure 2 (yes Figure 7 (a magnified schematic diagram of the waveform in the middle rectangular box);

[0035] Figure 9 This is a test of a liquid leakage detection device according to a preferred embodiment of the present invention. Figure 3 (yes Figure 8 (a magnified schematic diagram of the waveform in the middle rectangular box);

[0036] Figure 10 This is a test of a liquid leakage detection device according to a preferred embodiment of the present invention. Figure 4 (yes Figure 9 (a magnified schematic diagram of the waveform in FIG);

[0037] Figure 11 It is the instruction data of a liquid leakage detection device according to the preferred embodiment of the present invention. Figure 1 ;

[0038] Figure 12 It is the instruction data of a liquid leakage detection device according to the preferred embodiment of the present invention. Figure 2 ;

[0039] Figure 13 Schematic diagram of a gradient refraction optical path of a liquid leakage detection device according to a preferred embodiment of the present invention;

[0040] Among them, 1. Gradient refraction optical path; 2. Refraction prism 2; 3. Refraction prism 1. DETAILED DESCRIPTION

[0041] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. These drawings are simplified schematic diagrams that only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0042] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, bottom, top, etc.), the directional indications are only used to explain the relative positional relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly. The terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. Unless otherwise clearly specified and defined, the terms "set", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be a communication between the internal parts of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0043] Example 1, as Figure 1-Figure 3 A liquid leakage detection device is shown, comprising: a detection control circuit, a power supply circuit connected to the detection control circuit, a detection signal generating circuit, an echo signal acquisition circuit, and an alarm circuit. The detection control circuit includes a detection control chip, which is connected to the input of the detection signal generating circuit and provides a pulse signal to the detection signal generating circuit to drive an optical signal generator in the detection signal generating circuit for detection. The detection control chip is connected to an echo signal acquisition circuit, whose signal acquisition terminal corresponds to the optical signal generator and collects the optical signal emitted by the optical signal generator through the echo signal acquisition circuit. The output of the echo signal acquisition circuit is connected to the signal sampling terminal of the detection control chip. The detection control chip is also connected to a power amplifier circuit for amplifying and shaping the output signal of the echo signal acquisition circuit, and an alarm circuit for indicating the detection status. The detection control chip uses the STM32L011F3U6TR model, but is not limited to this. Other ARM Cortex-M core microcontrollers (MCUs) in the prior art can also be substituted according to actual usage requirements.

[0044] Specifically, the power supply circuit includes a reference voltage circuit and a voltage modulation circuit connected to the reference voltage circuit. The voltage modulation circuit outputs a DVCC terminal, and the DVCC terminal is a step-down output terminal. Furthermore, the reference voltage circuit includes a power supply VCC, the output terminal of the power supply VCC is connected to the positive electrode of the diode D1, and the negative electrode of the diode D1 is connected to the VIN node through the resistor R3; the voltage modulation circuit includes a step-down chip U2, the VIN pin of the step-down chip U2 is connected to the VIN node, and the VIN pin is grounded through the parallel filter capacitors C4 and C5, the SW pin of the step-down chip U2 is connected to the BOOT pin through the bootstrap capacitor C2, and the SW pin of the step-down chip U2 is connected to one end of the inductor L1. The other end of inductor L1 is connected to the DVCC terminal, which is the buck output terminal. The FB pin of buck chip U2 is connected to the DVCC terminal through resistor R6. The FB pin of buck chip U2 is connected to one end of resistor R8. The other end of resistor R8 is connected to the DVCC terminal through filter capacitor C3. The connection node between resistor R8 and filter capacitor C3 is grounded. A freewheeling diode D2 is connected in parallel across filter capacitor C3, and the inverting end of freewheeling diode D2 is connected to the DVCC terminal, while the non-inverting end of freewheeling diode D2 is grounded. Buck chip U2 uses the TPS54202DDCR model, but is not limited to this. Other buck chips in the prior art can also be replaced according to actual usage requirements.

[0045] Specifically, the echo signal acquisition circuit includes a signal receiving processor corresponding to the optical signal generator. The VCC pin of the signal receiving processor is connected to the DVCC terminal via a resistor R1. The VCC pin of the signal receiving processor is grounded together with the GND pin of the signal receiving processor via a capacitor C1. The OUT pin of the signal receiving processor is connected to the DVCC terminal via a resistor R2. The OUT pin of the signal receiving processor functions as a PWMOUT terminal and is connected to one of the sampling terminals of the detection control chip. The signal receiving processor used is model IRM-H238ST / TR2; however, this is not limited to this model. Other signal receiving processors available in the prior art can be substituted based on actual usage requirements.

[0046] Specifically, the optical signal generator uses an infrared emitter, the inverting end of the infrared emitter is connected to one of the control signal output ends of the detection control chip as the LEDOUT end, the positive end of the infrared emitter is connected to one end of the resistor R4, the other end of the resistor R4 is connected to one end of the adjustment potentiometer R5, and the other end of the adjustment potentiometer R5 is grounded; the adjustment end of the adjustment potentiometer R5 is connected to the DVCC end.

[0047] Specifically, the detection control circuit is also connected to a signal alarm output circuit, which includes a transistor Q1. The base of the transistor Q1 is connected to the SINOUT pin of the detection control chip through a voltage divider resistor R14. The base of the transistor Q1 is also grounded through a pull-down resistor R12. The collector of the transistor Q1 is connected to one end of the resistor R11, and the other end of the resistor R11 leads to the LIMOUT node to provide an alarm signal to the external device; the emitter of the transistor Q1 is grounded.

[0048] Specifically, the reset pin of the detection control chip of the detection control circuit leads to two paths, one is connected to the DVCC end through the pull-up resistor R7, and the other is grounded through the reset capacitor C6. The BOOT pin of the detection control chip is grounded through the resistor R9. The VDD pin of the detection control chip leads to two paths, one is grounded through the capacitor C7, and the other is connected to the DVCC end.

[0049] Specifically, the warning circuit includes several groups of warning branches with warning lights of different colors. One end of the warning lights of the several groups of warning branches is connected to the warning signal output end of the detection control chip, and the other end of the warning lights is connected to the DVCC end.

[0050] Example 2, based on Example 1, Figure 1-Figure 3 As shown, the detection control chip has built-in power amplification instructions and echo signal processing instructions. The SWDIO and SWCLK pins of the detection control chip in the detection control circuit are connected to the data transmission chip. Both the power amplification instructions and the echo signal processing instructions use existing instructions and are imported into the detection control chip through the data transmission chip.

[0051] Example 3, based on Example 1, Figures 1-4 As shown, the detection control chip is also connected to a power amplifier circuit, which includes a power amplifier chip. The positive input terminal of the power amplifier chip is connected to the PGA-INP pin of the detection control chip, and the output terminal of the power amplifier chip is connected to the PGA-OUT pin of the detection control chip; the negative input terminal of the power amplifier chip is connected to the output terminal of the power amplifier chip. The detection control chip has built-in echo signal processing instructions. The SWDIO pin and SWCLK pin of the detection control chip of the detection control circuit are connected to the data transmission chip. The echo signal processing instructions all use instructions in the prior art and are imported into the detection control chip through the data transmission chip.

[0052] Embodiment 4, a detection method of a liquid leakage detection device, is implemented using the liquid leakage detection device of embodiment 2 or embodiment 3; and comprises the following steps:

[0053] Provide working power to the detection signal generating circuit, echo signal collecting circuit and warning circuit through the power supply circuit;

[0054] The detection control chip of the detection control circuit provides a pulse signal, which is amplified and shaped by a virtual power amplification module established by the power amplification instruction built into the detection control chip and then provided to the detection signal generating circuit. The detection signal generating circuit obtains the amplified and shaped pulse signal, and drives the optical signal generator in the detection signal generating circuit through the amplified and shaped pulse signal. The optical signal generator irradiates the detection light on the detection monitoring area. After the detection light passes through the detection monitoring area, the detection light passing through the detection monitoring area is collected by the receiver in the echo signal acquisition circuit. The echo signal acquisition circuit converts the obtained detection light signal into an electrical signal as an echo signal and feeds it back to the detection control chip; the virtual echo signal processing module established by the echo signal processing instruction in the detection control chip processes the signal to obtain the detection result.

[0055] Embodiment 5, a detection method of a liquid leakage detection device, based on embodiment 4, further comprising:

[0056] Further, such as Figure 2 As shown, the detection control chip of the detection control circuit of the leakage detection device provides a pulse signal. The pulse signal is amplified and shaped by a virtual power amplification module established by the power amplification instruction built into the detection control chip or a power amplification circuit connected to the power amplification chip, and then provided to the detection signal generating circuit. The detection signal generating circuit obtains the amplified and shaped pulse signal, drives the optical signal generator detection signal generating circuit in the detection signal generating circuit through the amplified and shaped pulse signal, and emits detection light in the detection signal generating circuit.

[0057] The detection light passing through the detection area is received by the receiver in the echo signal acquisition circuit, and the acquired optical signal is analyzed into an electrical signal by the echo signal acquisition circuit. The analyzed electrical signal is introduced into the virtual echo signal processing module established by the echo signal processing instruction for processing and the detection result is issued through the detection control chip. The alarm operation is performed through the alarm circuit connected to the detection control chip, and the echo signal acquisition circuit feeds back to the detection control chip in real time to realize real-time monitoring.

[0058] Provide working power to the detection signal generating circuit, echo signal collecting circuit and warning circuit through the power supply circuit;

[0059] The power amplifier module transmits the pulse signal to the weak electrical signal emitted by the infrared transmitter for controlled amplification and shaping, ultimately outputting a square wave sequence that the Louye sensor logic circuitry uses to calculate and analyze the time of flight. The pulse signal is extremely weak and accompanied by interference, necessitating signal amplification and shaping within a specific timeframe.

[0060] Among them, the echo signal acquired by the echo signal acquisition circuit and input to the detection control chip is a weak damped oscillation electrical signal. After being processed by the receiving circuit, the signal of a specific time period can be selectively allowed to pass to the subsequent circuit. For weak echo signals, an LNA low-noise amplifier circuit is required. This part of the circuit is constructed using a low-noise, high-bandwidth integrated operational amplifier, but is not limited to this. The LNA amplifier on the chip dedicated to the ultrasonic pre-analog circuit in the existing technology can also be used, and is not limited to one type of amplifier.

[0061] After the signal is amplified by the LNA low-noise amplifier circuit, it is sent to the programmable gain amplifier circuit (PGA) for further amplification. The amplification factor can be programmed according to the control strategy of the logic circuit. The amplification factor range is 0~40dB. At this time, the signal amplitude is greatly improved. As one input signal of the comparator module internally burned in the detection control chip, it is sent to the comparator for comparison processing. The other input signal of the comparator module is generated by a programmable reference voltage source. As a comparison bias voltage, the reference 0 potential of the bias voltage is determined by the average voltage in a period of time before the echo signal arrives. The voltage value of the voltage source can be adjusted according to actual needs to achieve a better comparison effect and output a stable square wave sequence to the subsequent operation processing circuit. Figure 5 The figure shows the comparison between wavelength and receiving intensity. Figure 6 This is a comparison chart of frequency and reception strength.

[0062] like Figure 7-10 As shown in the figure, after receiving a square wave sequence, the logic circuit calculates the time when several square waves in the sequence appear after the sending pulse, and obtains the falling edge moment of each square wave. The first rising edge is recorded as T1, the second falling edge is recorded as T2, and so on. Generally, the algorithm can be completed by obtaining the falling edge time of about 5 square waves, and these time values ​​T1 to T5 are stored.

[0063] After receiving the second square wave sequence relative to the first, a similar calculation process is performed to obtain the T1-T5 values. Taking five square wave sequences as an example, with T3 as the typical value, the T3 value of the second square wave sequence is compared with the previously stored T3 value. If the change is minimal, the test is normal and no ghosting has occurred, and the cycle is repeated. If the T3 value changes significantly, a comparison is made from the second square wave sequence T1-T5 to determine which value is closest to the previously collected T3 value. This value is then updated as the T3 value for the current measurement. Subsequent calculations using this updated T3 value can eliminate the impact of ghosting on the flight time.

[0064] By comparing the time with the falling edge, it is determined whether there is liquid at the bottom of the sensor and an action signal is generated.

[0065] Specifically, each group has 5 falling edges, and each judgment cycle is 3s. The number of falling edges judged during this time is not less than 245. 250 falling edges will be generated in 3s. If there are less than 245 falling edges, the sensor will issue an alarm.

[0066] Further, such as Figure 11 、 Figure 12 The echo signal processing instructions shown are as follows. Figure 11 This is a standard GPIO external interrupt handler in the STM32 HAL library. The GPIO_Pin parameter identifies the pin that triggered the interrupt. When an interrupt occurs on the corresponding pin, the function is called. A macro reads the interrupt flag of the corresponding pin to determine whether an interrupt has been triggered. If the flag is not RESET (indicating an interrupt has been detected), the function proceeds conditionally to execute subsequent logic. The interrupt flag must be cleared after entering interrupt processing; otherwise, interrupts will continue to be triggered. The macro clears the interrupt pending flag for the corresponding pin to ensure that new interrupts can be properly responded to. A callback function, a "weak function" in the HAL library, is used by developers to customize the business logic after an interrupt is triggered. If the user requires additional interrupt processing, reimplement the HAL_GPIO_EXTI_Callback function. The counting logic increments the count variable by 1 each time a falling edge is detected to trigger an interrupt (after the flag is cleared and the callback is called), achieving the requirement of "count + 1 for each falling edge triggered." Falling edge detection depends on configuration: The code only handles the actions after the interrupt is triggered. However, in order for the pin to be able to detect the falling edge, the interrupt mode needs to be set to falling edge trigger in advance during GPIO initialization.

[0067] in, Figure 12This program logic, written based on the STM32 HAL library, implements PWM wave transmission, falling edge counting, and LED and pin state control. Within the main loop and PWM transmission logic, the program repeatedly executes internal logic. It starts channel 1 of the TIM timer and outputs a PWM wave. A 600-microsecond delay is applied (maintaining PWM output). The PWM output is stopped. A 600-microsecond delay (PWM off interval) is applied. This loop repeats five times, outputting five sets of "PWM on 600µs + off 600µs" waveforms. The "sending five sets of PWM waves" action is repeated 50 times. After each set of five PWM waves is sent, a 15-millisecond delay is applied to mitigate sensor signal attenuation. Within the falling edge counting and state control, the program checks whether the number of falling edges exceeds 245. If so, the LIM_OUT_Pin is reset, the green light (LED_GREEN_Pin) turns off, and the red light (LED_RED_Pin) turns on, indicating that the "no-water waveform" has not been reached, triggering an alarm. If the LIM_OUT_Pin is set to SET, the green light turns on and the red light turns off, indicating that the "no water waveform has been reached, no alarm." The device periodically outputs a PWM waveform (5 groups per cycle, repeated 50 times, with a 15ms delay) to drive a sensor or generate a detection signal. External interrupts are used to count the counts, reflecting the characteristics of the signal received by the sensor. The count value determines whether the sensor has detected the "no water waveform." GPIO is used to control the alarm pin and the red and green lights to display the status.

[0068] Example 6, based on Example 5, uses an intermittent signal (i.e., square wave detection) based on the following principles:

[0069] First, signal attenuation suppression. Continuous signal degradation is caused by hot carrier effects, capacitor memory effects, and dielectric polarization loss. Hot carrier effects: MOSFET devices generate Joule heating in the continuously on state, causing a decrease in transconductance (typical decay rate 0.5% / ms). Capacitor memory effects: The receiving-end coupling capacitor (typically 100nF) experiences voltage retention during continuous charge and discharge (a residual voltage > 5% requires 12ms to reset). Dielectric polarization loss: High-frequency signals (>10kHz) cause the dielectric loss tangent of the PCB substrate (FR-4) to increase to 0.02.

[0070] Then, an accelerated life test is performed during the critical discontinuity threshold determination. For a 12ms interval, the signal amplitude attenuation rate is ≤0.1dB. For an interval less than 12ms, the attenuation rate increases by 0.3dB for each 1ms reduction (nonlinear deterioration). TDR (time domain reflectometry) is used to verify the impedance matching recovery time: 10ms: characteristic impedance deviation >5%; 12ms: impedance recovers to 50Ω±1%.

[0071] When using a 15ms cycle: the time margin allocation strategy includes: an anti-interference processing window (5ms); an IIR band-stop filter to suppress power frequency / RF interference; a sliding average algorithm (32-point window length) to eliminate impulse noise; and a signal correction phase (7ms): temperature drift compensation (±5ppm / °C) and baseline calibration.

[0072] Robustness-enhancing measures include: dynamic threshold adjustment: automatically adjusting the trigger threshold (±3σ) based on the ambient noise level; phase lock compensation: using a PLL (phase-locked loop) to track signal phase drift (compensation range ±15°); and power supply decoupling optimization: adding a π-type filter to suppress switching noise (PSRR>60dB@100kHz).

[0073] In this embodiment, the system is collaboratively optimized, and the discontinuous mode in the energy efficiency management reduces the average power consumption by 87% (from 3.5mA in continuous mode to 45uA); a DC-DC buck converter (93% efficiency) is used in conjunction with the buck chip U2 to achieve a 9-fold reduction in power consumption; the electromagnetic compatibility design includes: a 15ms period to avoid the period of common interference sources (such as 20ms for 50Hz power frequency and 1ms frame interval for CAN bus).

[0074] Example 7: Based on Example 1 or Example 4, the specific parameters and features of this application are defined as follows:

[0075] In spectrum matching optimization, the optical signal generator uses a Si-based photodiode (response range 400-1100nm), achieving a quantum efficiency of 60%-70% at 940nm. This matches the IR-LED emission peak (typically 935-945nm) to maximize photoelectric conversion efficiency. Ambient light suppression at 940nm eliminates interference from visible light (400-700nm) and reduces sunlight / illumination noise. The detection control chip provides a bandpass filter with a center frequency of 38kHz.

[0076] Example eight, as Figure 13As shown, the optical signal generator is located on one side of the detection area, and the signal collection end is located on the other side of the detection area. A gradient refraction optical path 1 is provided in the detection area. The optical signal generator emits a light signal and enters the gradient refraction optical path 1. After passing through the detection area, the light signal is received by the signal collection end. The gradient refraction optical path 1 includes a refractive prism 1 3 that is sunken into the detection area (i.e., the outer surface of the refractive prism 1 3 contacts the leaked liquid in the detection area), and a refractive prism 2 2 located on the light incident side of the trapezoidal prism. Light from the optical signal generator is introduced from one side of the refractive prism 2 2, exits from the other side of the refractive prism 2 2, and enters the incident side of the refractive prism 1 3. The detection light forms a U-shaped detection optical path in the detection area through the refractive prism 1 3 and is then transmitted back to the signal collection end. The refractive prism 1 3 has an inverted trapezoidal structure. The refractive prism 2 2 is a triangular prism.

[0077] Working principle:

[0078] The present invention provides a non-contact liquid leakage detection device and method. Using a gradient refractive index optical path, the device achieves sub-second (0.3s) leak detection at hidden locations (ground clearance ≥ 15mm, achieved by a refractive prism 3 sunk into the detection area and cooperating with the lowest point in the detection area). Its non-contact detection mode avoids blind spots in manual inspections, and its modular design supports plug-and-play integration.

[0079] The above specific implementation methods are specific support for the scheme ideas proposed in the present invention, and cannot be used to limit the scope of protection of the present invention. Any equivalent changes or equivalent modifications made on the basis of this technical scheme in accordance with the technical ideas proposed in the present invention still fall within the scope of protection of the technical scheme of the present invention.

Claims

1. A liquid leakage detection device, characterized in that: include: A power supply circuit, and a detection control circuit, a detection signal generating circuit, an echo signal acquisition circuit, and a warning circuit electrically connected to the power supply circuit; The detection control circuit includes a detection control chip, which is connected to the input end of the detection signal generating circuit and provides a pulse signal to the detection signal generating circuit to trigger the optical signal generator in the detection signal generating circuit to perform detection; The detection control chip is connected to an echo signal acquisition circuit, the signal acquisition end of the echo signal acquisition circuit corresponds to the optical signal generator, and the optical signal emitted by the optical signal generator after passing through the detection area is collected by the echo signal acquisition circuit. The output end of the echo signal acquisition circuit is connected to the signal sampling end of the detection control chip; The detection control chip is also connected to a warning circuit for warning the detection status; The power supply circuit includes a reference voltage circuit and a voltage modulation circuit connected to the reference voltage circuit, the voltage modulation circuit leads to a DVCC terminal, and the DVCC terminal is a step-down output terminal; The echo signal acquisition circuit includes a signal receiving processor corresponding to the optical signal generator, the VCC pin of the signal receiving processor is connected to the DVCC terminal through a resistor R1, the VCC pin of the signal receiving processor is grounded at a common point with the GND pin of the signal receiving processor through a capacitor C1, the OUT pin of the signal receiving processor is connected to the DVCC terminal through a resistor R2, and the OUT pin of the signal receiving processor is connected to one of the sampling terminals of the detection control chip as a PWMOUT terminal; The reference voltage circuit includes a power supply VCC, the output end of the power supply VCC is connected to the anode of the diode D1, and the cathode of the diode D1 is connected to the VIN node through the resistor R3; The voltage modulation circuit includes a step-down chip U2, the VIN pin of the step-down chip U2 is connected to the VIN node, and the VIN pin is grounded through the parallel filter capacitor C4 and the filter capacitor C5, the SW pin of the step-down chip U2 is connected to the BOOT pin through the bootstrap capacitor C2, the SW pin of the step-down chip U2 is connected to one end of the inductor L1, the other end of the inductor L1 is the DVCC end, and the DVCC end is the step-down output end, the FB pin of the step-down chip U2 is connected to the DVCC end through the resistor R6, the FB pin of the step-down chip U2 is connected to one end of the resistor R8, the other end of the resistor R8 is connected to the DVCC end through the filter capacitor C3, the connection node between the resistor R8 and the filter capacitor C3 is grounded, and a freewheeling diode D2 is connected in parallel at both ends of the filter capacitor C3, and the inverting end of the freewheeling diode D2 is connected to the DVCC end, and the positive end of the freewheeling diode D2 is grounded.

2. A liquid leakage detection device according to claim 1, characterized in that: The optical signal generator is located on one side of the detection area, and the signal acquisition end is located on the other side of the detection area. A gradient refraction optical path is provided in the detection area. The optical signal generator emits an optical signal and enters the optical signal from the gradient refraction optical path, and is received by the signal acquisition end after passing through the detection area.

3. The liquid leakage detection device according to claim 2, characterized in that: The optical signal generator uses an infrared emitter, the inverting end of the infrared emitter is connected to one of the control signal output ends of the detection control chip as the LEDOUT end, the positive end of the infrared emitter is connected to one end of the resistor R4, the other end of the resistor R4 is connected to one end of the adjustment potentiometer R5, and the other end of the adjustment potentiometer R5 is grounded; the adjustment end of the adjustment potentiometer R5 is connected to the DVCC end.

4. The liquid leakage detection device according to claim 3, characterized in that: The detection control circuit is also connected to a signal alarm output circuit, which includes a transistor Q1. The base of the transistor Q1 is connected to the SINOUT pin of the detection control chip through a voltage divider resistor R14. The base of the transistor Q1 is also grounded through a pull-down resistor R12. The collector of the transistor Q1 is connected to one end of the resistor R11, and the other end of the resistor R11 leads to the LIMOUT node to provide an alarm signal to an external device; the emitter of the transistor Q1 is grounded.

5. The liquid leakage detection device according to claim 4, characterized in that: The reset pin of the detection control chip of the detection control circuit leads to two paths, one is connected to the DVCC end through the pull-up resistor R7, and the other is grounded through the reset capacitor C6. The BOOT pin of the detection control chip is grounded through the resistor R9. The VDD pin of the detection control chip leads to two paths, one is grounded through the capacitor C7, and the other is connected to the DVCC end.

6. The liquid leakage detection device according to claim 5, characterized in that: The warning circuit includes several groups of warning branches with warning lights of different colors, one end of the warning lights of the several groups of warning branches is connected to the warning signal output end of the detection control chip, and the other end of the warning lights is connected to the DVCC end; And / or, the gradient refraction optical path includes a refractive prism 1 sunk into the detection area, and a refractive prism 2 located on the light incident side of the trapezoidal prism. The light of the optical signal generator is introduced from one side of the refractive prism 2, and then output from the other side of the refractive prism 2 and enter the incident side of the refractive prism 1. The detection light forms a U-shaped detection optical path in the detection area through the refractive prism 1 and is sent back to the signal collection end.

7. The liquid leakage detection device according to claim 6, characterized in that: The SWDIO pin and SWCLK pin of the detection control chip of the detection control circuit are connected to the data transmission chip; And / or, the detection control chip is further connected to a power amplifier circuit, the power amplifier circuit includes a power amplifier chip, the non-phase input terminal of the power amplifier chip is connected to the PGA-INP pin of the detection control chip, and the output terminal of the power amplifier chip is connected to the PGA-OUT pin of the detection control chip; the inverting input terminal of the power amplifier chip is connected to the output terminal of the power amplifier chip; or, the detection control chip has a built-in power amplification instruction; And / or, the detection control chip has built-in echo signal processing instructions.

8. A detection method for a liquid leakage detection device, characterized in that: The method is implemented by using the liquid leakage detection device according to any one of claims 1 to 7; the method comprises the following steps: Provide working power to the detection signal generating circuit, echo signal collecting circuit and warning circuit through the power supply circuit; The detection control chip of the detection control circuit provides a pulse signal. The pulse signal is amplified and shaped by a virtual power amplification module established by the power amplification instruction built into the detection control chip or a power amplification circuit connected to the power amplification chip, and then provided to the detection signal generating circuit. The detection signal generating circuit obtains the amplified and shaped pulse signal, and drives the optical signal generator in the detection signal generating circuit through the amplified and shaped pulse signal. The optical signal generator irradiates the detection light on the detection monitoring area. After the detection light passes through the detection monitoring area, the detection light passing through the detection monitoring area is collected by the receiver in the echo signal acquisition circuit. The echo signal acquisition circuit converts the obtained detection light signal into an electrical signal as an echo signal and feeds it back to the detection control chip; the virtual echo signal processing module established by the echo signal processing instruction in the detection control chip processes the signal to obtain the detection result.

Images