New tunnel culvert automatic drainage early warning linkage system

Abstract

The application discloses a novel tunnel culvert automatic drainage early warning linkage system and relates to the technical field of municipal drainage. Water level sensing and a primary response end collect water depth. Three threshold values of early warning water level, drainage starting water level and dangerous water level are compared. When the drainage starting water level is reached, the automatic drainage pump is started. According to the water level drop rate, the drainage capacity abnormality is evaluated. On-site forced control and secondary alarm end switch the municipal traffic signal lamp to red light through the standard signal interface at the same time of starting drainage, and sound and light warning is carried out. Remote early warning and system reset end push the graded early warning to the remote platform through multi-mode communication, and link the IP camera to capture the on-site video. After the water accumulation is reduced to the safe water level, the system is automatically reset. If the water level rises during the reset process, the system is immediately interrupted. The application realizes the integrated linkage of water accumulation detection, forced traffic control, on-site secondary alarm and remote platform monitoring, and improves the traffic safety and emergency response capability under the tunnel culvert water accumulation scene.

Description

Technical Field

[0001] This invention relates to the field of municipal drainage technology, and in particular to a novel automatic drainage early warning and linkage system for tunnels and culverts. Background Technology

[0002] The new type of tunnel and culvert automatic drainage early warning linkage system is an intelligent protection system that integrates water accumulation monitoring, automatic drainage, traffic control and safety early warning. It can sense changes in water depth in real time, automatically start drainage equipment for emergency drainage, and warn and restrict the passage of vehicles and personnel about to enter or already in the water accumulation area by linking with traffic lights at the entrance and sound and light warning equipment along the tunnel.

[0003] Currently, relying solely on the simple warning lights built into the equipment is insufficient to link with the municipal traffic signal control system for mandatory traffic control. Furthermore, it lacks a secondary alarm mechanism along the direction of traffic, resulting in inadequate warning effectiveness over long distances. The reset sequence after water recedes is chaotic, lacking real-time assessment of drainage capacity degradation and failing to detect hidden faults such as pipe blockages. Additionally, the lack of IoT remote early warning and video linkage means the system is completely paralyzed when the main power supply or main control fails, making it impossible to maintain the traffic light's mandatory locking state. Moreover, there is no periodic self-checking mechanism, posing a high risk of operating with hidden faults.

[0004] Therefore, a new type of automatic drainage early warning and linkage system for tunnels and culverts is proposed to solve the above problems. Summary of the Invention

[0005] The main objective of this invention is to provide a novel automatic drainage early warning and linkage system for tunnels and culverts to solve the problems mentioned in the background above.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is: a novel automatic drainage early warning linkage system for tunnels and culverts, the system comprising a water level sensing and primary response terminal, an on-site mandatory control and secondary alarm terminal, and a remote early warning and system reset terminal; The water level sensing and primary response terminal collects the water depth in real time through a radar water level sensor and compares it according to a multi-level threshold. The multi-level threshold includes at least a first-level threshold for initiating pre-drainage in advance, a second-level threshold for triggering local early warning, and a third-level threshold for determining insufficient drainage capacity and triggering mandatory control. When the first-level threshold is reached, the drainage pump is automatically started for pre-drainage, and when the third-level threshold is reached, mandatory control is triggered. The on-site mandatory control and secondary alarm terminal is used to switch the municipal traffic lights to red to prohibit passage when the water accumulation reaches the third level threshold through the standard signal interface, and to provide flashing and voice warnings through the sound and light alarms deployed in the tunnel along the passage direction. The remote early warning and system reset terminal is used to push graded early warnings to a remote platform via IoT multimode communication when water accumulation exceeds the limit or equipment malfunctions, and automatically resets after the water level drops to a safe level, following the sequence of first stopping the pump, then turning off the green light, and finally turning off the alarm.

[0007] Preferably, the water level sensing and primary response terminal includes a water level detection module, an automatic drainage module, and a primary alarm module; The water level detection module includes a water level acquisition unit and a threshold comparison unit; The water level acquisition unit collects the water depth in real time in a non-contact manner using a millimeter-wave radar water level gauge. The threshold comparison unit compares the collected value with the preset three-level thresholds of warning water level, drainage start water level and dangerous water level through a microcontroller. The warning water level is lower than the drainage start water level, and the drainage start water level is lower than the dangerous water level.

[0008] Preferably, the automatic drainage module includes a drainage pump drive unit, a pump status detection unit, and a drainage capacity assessment unit; The drainage pump drive unit controls the start and stop of the drainage pump via a relay. The pump status detection unit detects the operating current of the drainage pump through a current transformer to determine whether it is working properly. The drainage capacity assessment unit generates a pipeline blockage warning when drainage efficiency drops abnormally by calculating the deviation between the water level drop rate and the rated flow rate.

[0009] Preferably, the primary alarm module includes a local warning light unit and a buzzer unit; The local warning light unit uses waterproof LED indicators to illuminate a yellow light at the warning water level and a red light at the drainage start water level. The buzzer unit emits an intermittent buzzer warning when the water level exceeds the limit via a waterproof buzzer.

[0010] Preferably, the on-site mandatory control and secondary alarm terminal includes a traffic light linkage module, an in-tunnel audible and visual alarm module, and a status interlock and fault bypass module; The traffic light linkage module includes a standard interface unit, a mandatory control unit, and a green light advance unit. The standard interface unit achieves electrical isolation connection with the municipal signal control system through a standard signal relay; The forced control unit keeps the red light constantly on until the water level recedes to a safe level through a self-locking circuit, and the trigger condition for the forced control unit is that the water level reaches a dangerous level. The green light warning unit is used to control the green light to flash and display a countdown when the water level is below the safe level and the difference is within the preset warning range, indicating that passage is about to resume.

[0011] Preferably, the cave-based audio-visual alarm module includes a voice broadcast unit, a flashing light unit, and a directional warning unit; The voice broadcast unit uses an MP3 module and a waterproof speaker to play warning messages in a loop. The strobe light unit drives the LED strobe light through a strobe control circuit, and the strobe frequency increases with the increase of water depth. The directional warning unit emits directional sound waves along the tunnel direction through a high-power directional loudspeaker, and enhances the warning effect by utilizing the reflection from the tunnel wall.

[0012] Preferably, the state interlock and fault bypass module includes a state interlock unit, a fault bypass unit, and a fault self-recovery unit; The state interlock unit implements hardware-level interlocking between the red and green lights through logic circuits; The fault bypass unit temporarily deactivates automatic control via a key switch after a system failure and on-site safety confirmation, allowing manual emergency passage and automatically reporting the bypass event to the remote platform. The fault self-recovery unit is used to automatically switch to the local LED text screen to display the danger of water accumulation and issue a buzzer alarm when the main control fails, while reporting the fault code to the remote early warning and system reset terminal.

[0013] Preferably, the remote early warning and system reset terminal includes an Internet of Things communication module, a remote platform docking module, and a system reset and self-test module; The IoT communication module includes a multi-mode communication unit, a data reporting unit, and a backup power supply unit. The multi-mode communication unit is used to simultaneously support 4G and NB-IoT, and automatically switches according to the on-site signal strength. The data reporting unit pushes water level data and equipment status to the cloud platform via the MQTT protocol, and the reporting frequency dynamically increases with the rate of water level rise. The backup power unit is used to automatically switch to the backup battery when the main power supply fails, maintain the traffic light lock logic for at least 2 hours and report the power failure event.

[0014] Preferably, the remote platform docking module includes a hierarchical push unit and a video linkage unit; The tiered push unit generates a Level 1 warning SMS + voice call, a Level 2 warning platform push, and a Level 3 warning emergency broadcast based on the water depth and the level of equipment abnormality. The video linkage unit is used to control the deployed IP cameras to capture images of the water accumulation site and record a 30-second short video before and after the warning is triggered. The water level data, captured images and short videos are packaged together and pushed to the remote platform for remote review by management personnel.

[0015] Preferably, the system reset and self-test module includes a water level threshold reset unit, a sequential reset control unit, and a timed self-test unit; The water level threshold reset unit outputs a reset trigger signal after the microcontroller determines that the water level is below the safe water level and remains stable for more than 10 seconds. The sequential reset control unit is used to perform a reset in the following sequence: first stop the drainage pump, then switch to green light after a 2-second interval, and then turn off the audible and visual alarm after a 2-second interval. If the water level rises during the reset process, the reset will be interrupted immediately and the system will re-enter the drainage control state. The timed self-test unit is used to perform daily timed checks on the effectiveness of the water level sensor, communication link detection, and no-load start-up tests of the drainage pump, generate logs, and report them to the remote platform.

[0016] The present invention has the following beneficial effects: 1. In this invention, a millimeter-wave radar water level gauge is used to collect the water depth non-contactly, avoiding measurement inaccuracies caused by silt and oil contamination; a single-chip microcomputer compares the collected values ​​with three threshold levels—warning water level, drainage start water level, and danger water level—to achieve graded early warning and avoid frequent start-stop cycles caused by a single threshold; when the drainage start water level is reached, a relay automatically starts the drainage pump to ensure timely drainage; a current transformer detects the operating current of the drainage pump to identify faults such as idling and overload in real time; by calculating the deviation between the water level drop rate and the rated flow rate, a pipe blockage warning is generated when drainage efficiency abnormally decreases, allowing maintenance personnel to intervene in advance, avoiding safety accidents caused by drainage failure, and improving the proactive early warning capability and operational reliability of the drainage system.

[0017] 2. In this invention, while drainage is initiated, a standard interface relay is electrically isolated from the municipal signal control system to achieve a forced switching of the traffic lights, compensating for the weak control effectiveness of simple warning lights; a self-locking circuit keeps the red light constantly on until the water level drops to the safety line, ensuring that vehicles and pedestrians are absolutely prohibited from entering during dangerous periods; the flashing frequency of the flashing lights inside the tunnel increases with the water depth, allowing personnel inside the tunnel to intuitively judge the level of danger and avoid accidental entry due to blind spots in long tunnels; a high-power directional speaker emits directional sound waves along the tunnel direction and uses tunnel wall reflection to enhance the warning effect, achieving long-distance forced warning; when the water level drops below the safe level by 5cm, the green light is controlled to flash and a countdown is set to announce the resumption of traffic, preventing sudden changes in the green light from causing traffic accidents and comprehensively improving traffic safety in flooded scenarios.

[0018] 3. In this invention, automatic switching between 4G and NB-IoT multi-mode communication is adopted to ensure uninterrupted communication in complex signal environments; water level and equipment status data are pushed through the MQTT protocol, with the reporting frequency dynamically increasing as the water level rises, enabling managers to grasp the trend of danger in real time; tiered early warnings are generated based on water depth and anomaly level via SMS, voice calls, platform push notifications, and emergency broadcasts, and linked with IP cameras to capture on-site images and 30-second short videos before and after for remote verification, reducing unnecessary deployments due to false alarms; after the water level drops to the safe line and stabilizes for 10 seconds, it resets in the following order: first, stop the pump; then, after a 2-second interval, switch to green light; and finally, after another 2-second interval, turn off the alarm. During the reset, if the water level rises again, the process is immediately interrupted and re-controlled to prevent secondary disasters; sensors, communication links, and drainage pumps are self-checked daily to proactively detect hidden faults; when the main power fails, the backup battery maintains the red light locked for at least 2 hours, and automatically switches to local text screen alarm when the main control fails, solving the danger of the red light accidentally going out due to system paralysis and improving the safety of unattended operation. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall system architecture of the novel automatic drainage early warning linkage system for tunnels and culverts of the present invention; Figure 2 This is a schematic diagram of the structure of the water level sensing and primary response end of the novel automatic drainage early warning linkage system for tunnels and culverts of the present invention. Figure 3 This is a schematic diagram of the on-site mandatory control and secondary alarm terminal of the novel automatic drainage early warning linkage system for tunnels and culverts of the present invention; Figure 4 This is a schematic diagram of the remote early warning and system reset terminal of the novel automatic drainage early warning linkage system for tunnels and culverts of the present invention. Detailed Implementation

[0020] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0021] Example 1, please refer to Figures 1-2 As shown: A new type of automatic drainage early warning and linkage system for tunnels and culverts. The system includes a water level sensing and primary response terminal, an on-site mandatory control and secondary alarm terminal, and a remote early warning and system reset terminal. The water level sensing and primary response end collects the water depth in real time through a radar water level sensor and compares it according to a multi-level threshold. The multi-level threshold includes at least a first-level threshold for initiating pre-drainage in advance, a second-level threshold for triggering local early warning, and a third-level threshold for determining insufficient drainage capacity and triggering mandatory control. When the first-level threshold is reached, the drainage pump is automatically started for pre-drainage, and when the third-level threshold is reached, mandatory control is triggered. The on-site mandatory control and secondary alarm terminal is used to switch the municipal traffic lights to red to prohibit passage when the water accumulation reaches the third level threshold through the standard signal interface, and to provide flashing and voice warnings through the sound and light alarms deployed in the tunnel along the passage direction. The remote early warning and system reset terminal is used to push graded early warnings to a remote platform via IoT multimode communication when water accumulation exceeds the limit or equipment malfunctions. After the water level drops to a safe level, it automatically resets in the order of stopping the pump, turning off the green light, and then turning off the alarm.

[0022] The water level sensing and primary response unit includes a water level detection module, an automatic drainage module, and a primary alarm module; The water level detection module includes a water level acquisition unit and a threshold comparison unit; The water level acquisition unit collects the water depth in real time using a millimeter-wave radar water level gauge in a non-contact manner. Specifically, in implementation: A millimeter-wave radar level gauge is installed on the sidewall or top of the tunnel, at a distance of no less than 0.5 meters from the designed highest water level. The radar emits a frequency-modulated continuous wave signal, the frequency of which changes linearly with time. Upon encountering the water surface, the signal is reflected back as an echo. By measuring the difference frequency between the emitted and echo signals, the water level is determined using the formula... Calculate the distance from the sensor to the water surface, where The distance from the radar to the water surface. At the speed of light, For difference frequency, The water depth is obtained by subtracting the measured distance from the radar installation elevation to obtain the frequency modulation slope. This method does not require contact with the water body, which can avoid measurement failure caused by silt, oil corrosion and floating objects blocking the measurement, and ensure long-term stable operation.

[0023] The threshold comparison unit uses a microcontroller to compare the collected values ​​with three preset threshold levels: warning water level, drainage start water level, and danger water level. The warning water level is lower than the drainage start water level, and the drainage start water level is lower than the danger water level. In specific implementation: The microcontroller reads the depth data output by the water level acquisition unit every 0.5 seconds and compares it with three thresholds stored in the EEPROM: the warning water level is set at 5cm above the road surface to trigger a primary warning; the drainage start water level is set at 10cm above the road surface to start the drainage pump; and the danger water level is set at 20cm above the road surface to trigger mandatory control and a secondary alarm. The comparison logic is as follows: if... If so, then set the warning sign; if Then the drainage start flag is set and a switch signal is output to drive the relay to close the drainage pump contactor; if If a danger sign is set and a report is sent to the remote end, the three-level threshold design can avoid frequent start-stops caused by water level fluctuations and ensure reasonable system response.

[0024] Two monitoring points are used for water level detection: one is located in an underground collection tank to monitor the water level. When the water level reaches the warning level, the microcontroller outputs a pre-drainage start signal to activate the drainage pump in advance to lower the water level in the collection tank to a safe level, thus delaying road flooding; the other is located in a low-lying area of ​​the road surface to monitor the actual depth of water accumulation on the road. The set value of the warning water level in the collection tank is related to the depth of the collection tank and local rainfall characteristics, and is generally taken as 40-60% of the tank depth to balance pre-drainage and avoid idling energy consumption. The actual centimeter values ​​of the three thresholds are only examples. In specific implementation, they should be determined comprehensively based on factors such as tunnel longitudinal slope, collection tank volume, and design drainage capacity. For example, the road surface warning water level is set at 3-8cm above the road surface, the drainage start water level is set at 8-15cm above the road surface, and the danger water level is set at 18-30cm above the road surface. These values ​​can be flexibly adjusted according to local hydrological data and operation and maintenance experience to balance flood control safety and daily traffic needs in different scenarios.

[0025] The automatic drainage module includes a drainage pump drive unit, a pump status detection unit, and a drainage capacity assessment unit; The drainage pump drive unit controls the start and stop of the drainage pump via relays. In practice: After receiving the drainage start signal, the microcontroller outputs a high level on the corresponding I / O port, energizing the intermediate relay coil. Its contacts close, connecting the AC contactor coil. The AC contactor's main contacts close, energizing the drainage pump motor. When the water level drops below the safe level and remains below it for 10 seconds, the microcontroller outputs a low level on its I / O port, de-energizing the intermediate relay, disconnecting the AC contactor, and stopping the drainage pump. A resistor-capacitor absorption circuit is installed between the relay and the contactor to suppress the reverse induced electromotive force during shutdown, protecting the control circuit.

[0026] The pump status detection unit uses a current transformer to detect the operating current of the drainage pump to determine whether it is working properly. In specific implementation: An open-type current transformer (with a transformation ratio selected based on the motor's rated current, such as 100:1) is installed on the power supply line of the drainage pump motor. The secondary output current of the transformer is converted into a voltage signal by a sampling resistor and sent to the ADC port of the microcontroller. The microcontroller reads the sampled value every 200 milliseconds, converts it into the effective value of the primary current, and compares it with the motor's rated current. If the operating current is lower than 20% of the rated current for 5 seconds, it is determined that the pump is running dry. If it exceeds 120% of the rated current for 3 seconds, it is determined that it is overloaded or stuck. If it is within the range of 80%-120% of the rated current, it is determined to be working normally. All of the above states are reported to the remote platform through the Internet of Things module.

[0027] The drainage capacity assessment unit generates a pipe blockage warning when drainage efficiency abnormally decreases by calculating the deviation between the water level drop rate and the rated flow rate. In practice: After the drainage pump starts, the microcontroller continuously collects water level data and calculates the average rate of water level drop every 10 seconds. : ; in The water level drop rate is expressed in cm / s. The water level is the current value in cm. The water level is 10 seconds later, in cm.

[0028] Based on the water surface area of ​​the flooded area (unit: m) 2 (The actual drainage flow rate needs to be calculated by back-calculating the data after on-site measurement and pre-setting in the microcontroller). : ; in The unit is m 3 / h; the coefficient 36 is derived from unit conversion (1cm / s=0.01m / s, multiplied by 3600s / h to get the coefficient 36).

[0029] Compare the actual flow rate with the pump's rated flow rate. (unit: m) 3 / h, taken from the pump nameplate parameters) Comparison: If If the flow rate remains below 30 seconds, it is determined that the drainage efficiency has decreased abnormally, generating a pipe blockage warning signal. This assessment method does not require the addition of a flow meter; it can indirectly determine the blockage status by using only the water level change rate. It is low in cost and highly reliable.

[0030] The primary alarm module includes a local warning light unit and a buzzer unit; The local warning light unit uses waterproof LED indicators to illuminate yellow at the warning water level and red at the drainage start water level. In practice: Install dual-color waterproof LED warning lights (IP65 protection rating) near the water level sensor or on the side wall of the tunnel entrance. The lights have built-in red and yellow LEDs and are driven by two independent I / O ports of a microcontroller. After threshold comparison, if the current water level reaches the warning level (5cm above the road surface) but has not reached the drainage start level, the microcontroller outputs a high level to keep the yellow LED on. If the current water level reaches or exceeds the drainage start level (10cm above the road surface), the yellow LED turns off, and the red LED stays on. If the water level drops below the warning level, all LEDs turn off. The red and yellow colors distinguish different levels of danger, making it easy for on-site inspectors to quickly determine the water accumulation status.

[0031] The buzzer unit uses a waterproof buzzer to emit intermittent beeping alerts when water accumulation exceeds the limit. Specifically: A waterproof piezoelectric buzzer (sound pressure level ≥85dB@1m) is installed in or near the same housing as the warning light. It is driven by a microcontroller's PWM output port through a transistor switching circuit, and the buzzer's sounding mode automatically switches according to the water level. When the water level reaches the drainage start level but not the danger level (20cm above the road surface), the microcontroller outputs a pulse signal with a frequency of 1kHz and a duty cycle of 50%, which lasts for 0.5 seconds and then stops for 0.5 seconds, forming an intermittent beeping sound.

[0032] When the water level reaches the danger level, a continuous 1kHz pulse is output, and the buzzer sounds continuously, forming an urgent warning.

[0033] When the water level drops below the drainage start level and remains below it for 5 seconds, the microcontroller stops outputting the PWM signal and the buzzer turns off. If the water level drops from the danger level to between the drainage start level and the danger level (still ≥ drainage start but < danger), the buzzer automatically switches from continuous beeping to intermittent beeping mode.

[0034] The intermittent / continuous mode of the buzzer and its linkage with the red and yellow LED lights create a complementary sound and light effect, enhancing the warning effect on on-site personnel and ensuring timely detection when visibility is poor or attention is distracted.

[0035] Example 2, please refer to Figure 3 As shown: The on-site mandatory control and secondary alarm terminal includes a traffic light linkage module, an in-tunnel audible and visual alarm module, and a status interlock and fault bypass module; The traffic light linkage module includes a standard interface unit, a mandatory control unit, and a green light advance unit; The standard interface unit achieves electrical isolation connection with the municipal signal control system through standard signal relays. In specific implementation: A signal relay module with built-in optocoupler isolation is selected. The input end connects to the microcontroller's I / O port, and the output end connects to the corresponding red and green light control terminals of the municipal signal controller via an aviation connector. Optocoupler isolation ensures that the withstand voltage between the control side and the load side of this system is not less than 1500V, preventing interference or damage to municipal signal equipment in case of system failure. When the microcontroller outputs a low level, the relay coil is energized, and its normally open contact closes, shorting the red light control terminal of the signal controller to the common terminal, simulating the action of manually pressing the red light button. Green light control is achieved by another relay in the same way. The electrical isolation design meets the safety access requirements of municipal facilities and ensures the reliability of linkage.

[0036] The forced control unit uses a self-locking circuit to keep the red light constantly on until the water level recedes to a safe level. The trigger condition for this forced control unit is that the water level reaches a dangerous level. Specifically, in implementation: A dual self-locking mechanism, combining hardware and software, is employed. On the software side, a self-locking flag is set in the microcontroller. When the water level first reaches the drainage start level, the flag is set to 1, and a red light control signal is continuously output. Even if the water level drops briefly due to fluctuations, the red light remains on as long as the flag is not cleared. On the hardware side, a set of normally open contacts of the red light relay is connected in parallel to the coil's starting circuit. Once the coil is energized, it sustains power through these contacts. The self-locking release condition is: the water level is below the safe level (2cm above the road surface) and remains stable for more than 10 seconds, while the remote warning terminal confirms that the water has receded to the safe level (i.e., the system self-check is normal or a reset permission signal is issued remotely by management personnel). This dual hardware and software self-locking effectively prevents the red light from accidentally going out due to water level fluctuations or microcontroller program malfunctions, ensuring that passage is strictly prohibited during dangerous periods.

[0037] The mandatory control unit only triggers mandatory control when the water level reaches a dangerous level. At this point, it is determined that the drainage capacity is insufficient to cope with the incoming water volume, and traffic must be immediately closed and personnel evacuated from the tunnel. When the pre-drainage strategy of the sump is in effect and there is no water accumulation on the road surface or the water level has not reached a dangerous level, traffic signals remain in normal operation and do not affect daily traffic efficiency.

[0038] The green light warning unit is used to control the green light to flash and display a countdown when the water level is below the safe level and the difference is within a preset warning range, indicating that passage is about to resume. The warning range is generally set to 3-10cm, preferably 5cm, and can be adjusted according to factors such as tunnel length and design speed. In specific implementation: The microcontroller monitors the difference between the current water level and the safe water level in real time. When the water level drops to 5cm above the safe level, the microcontroller enters the green light warning mode: it controls the green light relay to switch on and off at a frequency of 1Hz, causing the municipal green light to flash; simultaneously, it drives the LED countdown display at the entrance through the RS485 interface, calculating the warning recovery time according to the formula. ; in The estimated recovery time is in seconds. This is the current water depth, in cm. The safe water level is 2cm above the road surface, and the unit is cm. The average rate of water level drop over the last 30 seconds, in cm / s; the display shows the calculated value. The countdown begins by decreasing by 1 second, and is recalculated and refreshed every second based on the latest water level and rate of descent to ensure accurate warnings. When the water level drops below the safe level (2cm), the countdown resets to zero, and the green light changes from flashing to solid. This warning function prevents drivers from being caught off guard by the direct switch from green to red, reducing the risk of traffic accidents.

[0039] The cave-based audio-visual alarm module includes a voice broadcast unit, a flashing light unit, and a directional warning unit. The voice broadcast unit uses an MP3 module and a waterproof speaker to loop warning messages. In practice: A waterproof loudspeaker (IP65 protection rating) is installed every 50 meters along the direction of travel inside the tunnel or culvert. All loudspeakers are connected in parallel to an MP3 playback module. This module is controlled by a microcontroller via serial port commands and has a built-in TF card storing pre-recorded warning voice files (such as water accumulation ahead, prohibition of passage, etc.). When the water level reaches the drainage activation level (10cm above the road surface), the microcontroller sends a playback command, and the MP3 module loops the first voice message. When the water level reaches the danger level (20cm above the road surface), it switches to playing emergency voice messages. The voice broadcast is triggered synchronously with the traffic lights at the tunnel entrance to ensure that personnel inside the tunnel receive a clear warning even if they cannot see the entrance signals.

[0040] The strobe light unit drives the LED strobe lights through a strobe control circuit, and the strobe frequency increases with the depth of the water. In practice: Install a set of red LED strobe lights (each set with a power of no less than 10W) ​​every 30 meters on the tunnel sidewall or arch. The microcontroller calculates the strobe frequency according to the current water level using a linear formula.

[0041] in The current strobe frequency (in Hz); The lowest frequency (taken as 1Hz); The highest frequency (4Hz) is used. The starting water level for drainage is 10cm. The water level is dangerous (20cm). The current water depth (in cm); when hour ,when hour The frequency increases linearly in the middle; the microcontroller outputs a pulse signal of the corresponding frequency to drive the MOS tube and control the on and off of the LED light group. The frequency increases with the increase of the danger level, so that the people in the cave can intuitively judge the severity of the water accumulation and form a coded warning of the danger level.

[0042] The directional warning unit emits directional sound waves along the tunnel direction through a high-power directional loudspeaker, utilizing tunnel wall reflections to enhance the warning effect. In practice: Two parametric array directional loudspeakers (ultrasonic speakers) are installed 50 meters inside the tunnel entrance and in the middle of the tunnel. The pointing angle is controlled within ±15°, with the main lobe pointing towards the depth of the tunnel along the tunnel axis. The loudspeaker utilizes the nonlinear acoustic effect of air to modulate audible sound waves onto an ultrasonic carrier wave for transmission. During propagation, it recovers highly directional audible sound through self-demodulation. When the water level reaches the drainage activation level, the loudspeaker plays a directional warning sound repeatedly: "Danger of flooding, do not enter." Because the tunnel wall is a hard and smooth surface, the sound waves form a waveguide effect inside the tunnel. After reflection and superposition, the sound pressure attenuates by less than 10dB over a distance of 100 meters, which is far superior to ordinary loudspeakers. This directional warning unit can ensure that after a warning is issued at the tunnel entrance, the warning content can still be clearly heard within a 100-meter depth inside the tunnel, solving the problem of insufficient coverage of a single warning point in a long tunnel.

[0043] The state interlock and fault bypass module includes a state interlock unit, a fault bypass unit, and a fault self-recovery unit; The state interlock unit implements hardware-level interlocking between red and green lights through logic circuits. Specifically, in implementation: A double-pole double-throw intermediate relay is added to the control cabinet as an interlock relay. The coil of this relay is controlled by the microcontroller's passage permission signal (active high). Its two sets of switching contacts are connected in series in the red light relay coil circuit and the green light relay coil circuit, respectively. The connection method is as follows: when the interlock relay coil is not energized, its normally closed contact closes to connect the red light relay coil circuit, and at the same time, its normally open contact opens to open the green light relay coil circuit, ensuring that the green light cannot be lit when the red light is on. When the microcontroller determines that the water level is safe and passage is permitted, it outputs a high level to energize the interlock relay coil, the contact state flips, the red light circuit is disconnected, and the green light circuit is connected. This pure hardware interlock method does not rely on the microcontroller program logic. Even if the microcontroller program malfunctions or the I / O port outputs an error signal, the red and green lights will not light up at the same time, which complies with the safety regulations for traffic signal control.

[0044] The fault bypass unit temporarily deactivates automatic control via a key switch after a system failure and on-site safety confirmation, allowing manual emergency passage and automatically reporting the bypass event to the remote platform. In specific implementation: A three-position key switch with a lock is installed on the control cabinet panel, with positions for automatic, bypass, and manual reset. The contact signals of each position are connected to the microcontroller's I / O port. When a system fault occurs (such as water level sensor failure or communication interruption), and the on-site management personnel confirm that the accumulated water has been drained or there is no danger on site, the management personnel turn the key to the bypass position. After the microcontroller detects this signal, it immediately forcibly releases the self-locking state of the traffic lights, cancels the red light control signal, and switches the green light on, while simultaneously blocking all subsequent automatic triggering conditions. After bypass is activated, the microcontroller reports a bypass event record to the remote platform through the IoT module, including the bypass trigger time, the operator (who needs to be registered separately), and the current system status. The manual reset position is used to restore the system from bypass mode to automatic mode after the fault is cleared, restoring the normal monitoring function of the system. This unit ensures the feasibility and traceability of on-site manual intervention in extreme abnormal situations.

[0045] The fault self-recovery unit is used to automatically switch to displaying the water accumulation danger on the local LED text screen and sounding an alarm when the main control fails. Simultaneously, the fault code is reported to the remote early warning and system reset terminal. In specific implementation: In addition to the main control microcontroller, an independent hardware watchdog timer (such as MAX813L) and a backup microcontroller (low-power type) are added. The main control microcontroller sends a feed pulse to the watchdog every 5 seconds. If the watchdog does not receive a pulse for 10 consecutive seconds, it determines that the main control has failed, and its reset output pin outputs a reset signal to trigger the backup microcontroller to power on and start. After the backup microcontroller starts, it immediately drives the LED text screen installed at the tunnel entrance to display the danger of water accumulation and prohibits passage. At the same time, it drives the active buzzer to emit a continuous alarm. The backup microcontroller also sends a fault code to the remote warning terminal through the Internet of Things module. The fault code format is main control failure and timestamp (if the water level value cannot be obtained, it is reported as unknown). This ensures that the system can still maintain basic safety warning functions in the event that the main controller completely crashes or the program runs away, avoiding dangerous situations without any warning.

[0046] Example 3, please refer to Figure 4 As shown: The remote early warning and system reset terminal includes an IoT communication module, a remote platform docking module, and a system reset and self-test module; The IoT communication module includes a multi-mode communication unit, a data reporting unit, and a backup power supply unit; The multi-mode communication unit is used to simultaneously support 4G and NB-IoT, automatically switching according to the signal strength on site. In specific implementation: A communication module integrating 4G and NB-IoT dual-mode (such as the EC200U series) is selected and connected to a microcontroller via a serial port. The microcontroller reads the current 4G and NB-IoT signal strength indicators (RSRP, in dBm) every 30 seconds. Preset switching thresholds are used: if 4G is currently in use, and the RSRP is below -110dBm for three consecutive times while the NB-IoT RSRP is above -100dBm, the system switches to NB-IoT; if NB-IoT is currently in use, and the RSRP is below -105dBm for three consecutive times while the 4G RSRP is above -108dBm, the system switches to 4G. During the switching process, unsent data is temporarily stored in local Flash memory and retransmitted after the link is restored. This ensures high-speed 4G transmission when the signal is good at the tunnel entrance, and automatic switching when NB-IoT coverage is dominant deep within the tunnel, guaranteeing uninterrupted communication.

[0047] The data reporting unit pushes water level data and equipment status to the cloud platform via the MQTT protocol, and the reporting frequency dynamically increases with the rate of water level rise. Specifically, in implementation: The microcontroller has a built-in MQTT client that connects to the MQTTBroker specified on the cloud platform. It publishes topics such as tunnel / waterlevel, and reports data in JSON format, including fields such as water level value, water level rise rate, drainage pump status, and traffic light status. The water level rise rate is calculated based on the most recent minute. ; in The rate of water level rise (unit: cm / s); Current water level (unit: cm); This is the water level value (in cm) from 1 minute ago. If data from 1 minute ago is missing, then... Reporting frequency dynamic adjustment rules: The baseline reporting interval is 60 seconds; when When, the interval is shortened to 30 seconds; when When the water level exceeds the danger level (20cm above the road surface), the interval is shortened to 10 seconds; when the water level exceeds the danger level, it is forced to report every 5 seconds. The dynamic frequency can provide high-density data for remote decision-making when the water level rises rapidly, while saving traffic and power consumption during normal times.

[0048] The backup power unit is used to automatically switch to the backup battery when the main power supply fails, maintain the traffic light lockout logic for at least 2 hours, and report the power failure event. In specific implementation: A 12V / 7Ah maintenance-free lead-acid battery is connected in parallel at the system power input. It is connected to the system via an automatic switching module consisting of two Schottky diodes and a voltage detection circuit. When the main power supply is normal, the main power voltage is higher than the battery voltage, and the main power supply provides power while simultaneously providing float charging to the battery via a charging management chip. When the main power voltage drops below 11V for 200 milliseconds, the switching module automatically cuts off the main power circuit and switches to battery power. The switching process is uninterrupted, and the system does not lose power. The microcontroller monitors the main power status in real time through a voltage detection pin. Once a main power failure is detected, it immediately reports the main power failure event through the IoT module and reduces the power consumption of non-essential peripherals (such as LED text displays and voice broadcasts), prioritizing the power supply to the traffic light self-locking circuit and the communication module. Actual testing shows that the 7Ah battery can continuously operate for more than 2 hours while maintaining the red light lock (approximately 500mA) and the communication module (approximately 100mA), ensuring that the communication link does not fail during dangerous situations.

[0049] The remote platform integration module includes a tiered push unit and a video linkage unit; The tiered alert unit generates Level 1 warning SMS + voice call, Level 2 warning platform push, and Level 3 warning emergency broadcast based on water depth and equipment malfunction level. In practice: A tiered push logic is established within the microcontroller, with push conditions linked to water level thresholds and device status: When the water level reaches the danger level (20cm above the road surface), or when the drainage pump has been running continuously for more than 30 minutes and the water level is dropping at a rapid rate... When the water level remains below 0.05 cm / s (i.e., the water level has not dropped significantly), a Level 1 warning is triggered. The microcontroller calls the third-party SMS gateway interface through the IoT module to send an alarm SMS (containing the tunnel location, current water level, and timestamp) to the pre-bound administrator's mobile phone number. At the same time, it automatically dials the administrator's phone number through the voice call interface and plays a TTS synthesized voice broadcast to report the danger.

[0050] When the water level reaches the drainage start-up level (10cm above the road surface) but does not reach the danger level, or when the drainage capacity assessment unit generates a pipeline blockage warning, a level 2 warning is triggered; the microcontroller only pushes alarm events to the cloud platform via the MQTT protocol, and the platform highlights the fault point on the GIS map and records the log.

[0051] When the water level reaches the warning level (5cm above the road surface), a level 3 warning is triggered. The microcontroller sends a standardized warning signal code (such as 0101 representing a level 3 warning for tunnel water accumulation) through the emergency broadcast interface (such as RS232 to RJ45 connected to the control unit of the city emergency broadcast system). The emergency broadcast system then automatically broadcasts the warning to the surrounding area.

[0052] A three-tiered classification mechanism avoids information overload and ensures that events of varying severity are communicated appropriately to the relevant recipients; among these, the rate of water level decline... Defined as the decrease in water level per unit time after the drainage pump is started, in cm / s. If the water level remains below 0.05 cm / s for 30 minutes, it indicates that the drainage effect is almost ineffective and requires emergency manual intervention.

[0053] The video linkage unit is used to control the deployed IP cameras to capture images of the water accumulation site and record a 30-second short video before and after the warning is triggered. The water level data, captured images, and short video are packaged and pushed to a remote platform for remote review by management personnel. In specific implementation: IP cameras supporting the ONVIF protocol are pre-deployed in areas prone to water accumulation within the tunnel, and assigned fixed IP addresses. The microcontroller communicates with the cameras via HTTP API. When an alert is triggered (water level reaches any alert level or equipment malfunctions), a snapshot command is immediately sent, and the camera returns a JPEG image of the current scene. Simultaneously, a recording command is sent, and the camera records 30 seconds backward from the current moment and 30 seconds forward, generating a short MP4 video file in H.264 format. The captured images and videos are uploaded to a designated storage server on the cloud platform via FTP or HTTP. After the upload is complete, the microcontroller assembles the water level data, equipment status, image URL, and video URL into a JSON message packet and pushes it to the remote platform via MQTT. Management personnel can directly view the real-time situation by clicking on the alert record on the platform interface, determine whether the water accumulation has affected traffic or caused a false alarm, and make an accurate decision on whether to dispatch personnel to handle the situation. The video linkage function reduces the manual cost of on-site verification and improves emergency response efficiency.

[0054] The system reset and self-test module includes a water level threshold reset unit, a sequential reset control unit, and a timed self-test unit; The water level threshold reset unit uses a microcontroller to determine if the water level is below the safe level and remains stable for more than 10 seconds before outputting a reset trigger signal. In practice: The safe water level is set at 2cm above the road surface (i.e., the target water level for stopping the drainage pump). The microcontroller reads the water level data every 0.5 seconds and maintains a stable timer (in seconds). The timing rules are as follows: if the current water level is lower than the safe water level, the stable timer increments by 0.5 seconds; if the current water level is equal to or higher than the safe water level, the stable timer is reset to zero. When the accumulated value of the stable timer reaches 10 seconds, the microcontroller outputs a high-level pulse with a width of 200ms as a reset trigger signal. To prevent false resets caused by water level fluctuations, the sampling frequency and duration can be adjusted according to the site conditions, but the basic logic of accumulating 10 seconds remains unchanged. This unit ensures that the water level has indeed receded and stabilized before allowing a reset, avoiding frequent start-stop of the drainage pump or traffic signal disruptions caused by instantaneous water level fluctuations.

[0055] The sequential reset control unit is used to perform a reset in the following sequence: first, stop the drainage pump; then, switch to green light after a 2-second interval; and finally, turn off the audible and visual alarm after another 2-second interval. If the water level rises during the reset process, the reset is immediately interrupted and the system re-enters drainage control mode. Specifically, in implementation: After receiving the reset trigger signal, the microcontroller first executes the following steps: setting the I / O port of the drainage pump drive unit to a low level to stop the drainage pump and recording the stop timestamp. After waiting for 2 seconds (implemented by a software timer), it executes the following steps: canceling the red light forced lock signal, outputting a green light constant-on control signal, and clearing the self-locking flag. After waiting for another 2 seconds, it executes the following steps: turning off the voice broadcast and flashing lights of the tunnel's audible and visual alarm module, and turning off the local LED warning light. During the execution of the above three steps, the microcontroller monitors the current water level in real time. If the water level is detected to rise to the drainage start water level (10cm above the road surface) or above at any time, the remaining reset steps are immediately interrupted, the drainage start signal and red light lock signal are re-outputted, the audible and visual alarm is restored, and the reset interrupt event is reported to the remote platform. This sequential control logic prevents safety vulnerabilities caused by sudden water inflow during the reset process, ensuring that the system is always in a safe and controllable state.

[0056] The timed self-test unit is used to perform daily timed checks on the effectiveness of the water level sensor, communication link detection, and no-load start-up tests of the drainage pump, generating logs and reporting them to the remote platform. In specific implementation: The microcontroller has a built-in real-time clock that is set to automatically trigger a self-test process at 3:00 AM every day (during off-peak traffic hours).

[0057] Water level sensor validity check: The microcontroller sends a self-test command to the radar water level gauge and reads the self-test status byte returned by it. If the status byte indicates that the sensor is normal and the analog output value is within the expected range, it is considered valid; otherwise, the sensor is marked as faulty.

[0058] Communication link detection: The microcontroller sends a PING message (heartbeat packet) to the cloud platform through the IoT module. If a response is received from the platform within 30 seconds, the link is normal; if there is no response after 3 consecutive attempts, the communication is considered abnormal.

[0059] Drainage pump no-load start test: After confirming that the water level has dropped below the safe level since the last drainage stopped and that the current water level is lower than the pump inlet (which can be determined by the water level sensor), the microcontroller controls the drainage pump drive unit to start the drainage pump, which runs continuously for 5 seconds and then stops. During operation, the no-load current is detected by the current transformer: if the no-load current is less than 20% of the rated current, it is considered normal; if the no-load current exceeds 50% of the rated current, it is determined that the pump is mechanically stuck or the winding is short-circuited.

[0060] All self-test results (normal or abnormal) generate a log record with a timestamp, which is stored in the local EEPROM and simultaneously reported to the remote platform through the IoT module. Serious faults found by self-test (such as sensor failure or water pump jamming) immediately trigger a level one warning and push an SMS notification to the administrator. Self-test can proactively discover potential faults, avoid the system from running with defects for a long time during unattended periods, and improve the reliability and maintainability of the system.

[0061] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A novel automatic drainage early warning and linkage system for tunnels and culverts, characterized in that, The system includes a water level sensing and primary response terminal, an on-site mandatory control and secondary alarm terminal, and a remote early warning and system reset terminal. The water level sensing and primary response terminal collects the water depth in real time through a radar water level sensor and compares it according to a multi-level threshold. The multi-level threshold includes at least a first-level threshold for initiating pre-drainage in advance, a second-level threshold for triggering local early warning, and a third-level threshold for determining insufficient drainage capacity and triggering mandatory control. When the first-level threshold is reached, the drainage pump is automatically started for pre-drainage, and when the third-level threshold is reached, mandatory control is triggered. The on-site mandatory control and secondary alarm terminal is used to switch the municipal traffic lights to red to prohibit passage when the water accumulation reaches the third level threshold through the standard signal interface, and to provide flashing and voice warnings through the sound and light alarms deployed in the tunnel along the passage direction. The remote early warning and system reset terminal is used to push graded early warnings to a remote platform via IoT multimode communication when water accumulation exceeds the limit or equipment malfunctions, and automatically resets after the water level drops to a safe level, following the sequence of first stopping the pump, then turning off the green light, and finally turning off the alarm.

2. The novel automatic drainage early warning and linkage system for tunnels and culverts according to claim 1, characterized in that, The water level sensing and primary response terminal includes a water level detection module, an automatic drainage module, and a primary alarm module; The water level detection module includes a water level acquisition unit and a threshold comparison unit; The water level acquisition unit collects the water depth in real time in a non-contact manner using a millimeter-wave radar water level gauge. The threshold comparison unit compares the collected value with the preset three-level thresholds of warning water level, drainage start water level and dangerous water level through a microcontroller. The warning water level is lower than the drainage start water level, and the drainage start water level is lower than the dangerous water level.

3. The novel automatic drainage early warning and linkage system for tunnels and culverts according to claim 2, characterized in that, The automatic drainage module includes a drainage pump drive unit, a pump status detection unit, and a drainage capacity assessment unit. The drainage pump drive unit controls the start and stop of the drainage pump via a relay. The pump status detection unit detects the operating current of the drainage pump through a current transformer to determine whether it is working properly. The drainage capacity assessment unit generates a pipeline blockage warning when drainage efficiency drops abnormally by calculating the deviation between the water level drop rate and the rated flow rate.

4. The novel automatic drainage early warning and linkage system for tunnels and culverts according to claim 2, characterized in that, The primary alarm module includes a local warning light unit and a buzzer unit; The local warning light unit uses waterproof LED indicators to illuminate a yellow light at the warning water level and a red light at the drainage start water level. The buzzer unit emits an intermittent buzzer warning when the water level exceeds the limit via a waterproof buzzer.

5. The novel automatic drainage early warning and linkage system for tunnels and culverts according to claim 1, characterized in that, The on-site mandatory control and secondary alarm terminal includes a traffic light linkage module, an in-tunnel sound and light alarm module, and a status interlock and fault bypass module. The traffic light linkage module includes a standard interface unit, a mandatory control unit, and a green light advance unit. The standard interface unit achieves electrical isolation connection with the municipal signal control system through a standard signal relay; The forced control unit keeps the red light constantly on until the water level recedes to a safe level through a self-locking circuit, and the trigger condition for the forced control unit is that the water level reaches a dangerous level. The green light warning unit is used to control the green light to flash and display a countdown when the water level is below the safe level and the difference is within the preset warning range, indicating that passage is about to resume.

6. The novel automatic drainage early warning and linkage system for tunnels and culverts according to claim 5, characterized in that, The cave-based audio-visual alarm module includes a voice broadcast unit, a flashing light unit, and a directional warning unit; The voice broadcast unit uses an MP3 module and a waterproof speaker to play warning messages in a loop. The strobe light unit drives the LED strobe light through a strobe control circuit, and the strobe frequency increases with the increase of water depth. The directional warning unit emits directional sound waves along the tunnel direction through a high-power directional loudspeaker, and enhances the warning effect by utilizing the reflection from the tunnel wall.

7. The novel automatic drainage early warning and linkage system for tunnels and culverts according to claim 5, characterized in that, The state interlock and fault bypass module includes a state interlock unit, a fault bypass unit, and a fault self-recovery unit; The state interlock unit implements hardware-level interlocking between the red and green lights through logic circuits; The fault bypass unit temporarily deactivates automatic control via a key switch after a system failure and on-site safety confirmation, allowing manual emergency passage and automatically reporting the bypass event to the remote platform. The fault self-recovery unit is used to automatically switch to the local LED text screen to display the danger of water accumulation and issue a buzzer alarm when the main control fails, while reporting the fault code to the remote early warning and system reset terminal.

8. The novel automatic drainage early warning and linkage system for tunnels and culverts according to claim 1, characterized in that, The remote early warning and system reset terminal includes an Internet of Things communication module, a remote platform docking module, and a system reset and self-test module; The IoT communication module includes a multi-mode communication unit, a data reporting unit, and a backup power supply unit. The multi-mode communication unit is used to simultaneously support 4G and NB-IoT, and automatically switches according to the on-site signal strength. The data reporting unit pushes water level data and equipment status to the cloud platform via the MQTT protocol, and the reporting frequency dynamically increases with the rate of water level rise. The backup power unit is used to automatically switch to the backup battery when the main power supply fails, maintain the traffic light lock logic for at least 2 hours and report the power failure event.

9. The novel automatic drainage early warning and linkage system for tunnels and culverts according to claim 8, characterized in that, The remote platform integration module includes a hierarchical push unit and a video linkage unit; The tiered push unit generates a Level 1 warning SMS + voice call, a Level 2 warning platform push, and a Level 3 warning emergency broadcast based on the water depth and the level of equipment abnormality. The video linkage unit is used to control the deployed IP cameras to capture images of the water accumulation site and record a 30-second short video before and after the warning is triggered. The water level data, captured images and short videos are packaged together and pushed to the remote platform for remote review by management personnel.

10. The novel automatic drainage early warning and linkage system for tunnels and culverts according to claim 8, characterized in that, The system reset and self-test module includes a water level threshold reset unit, a sequential reset control unit, and a timed self-test unit; The water level threshold reset unit outputs a reset trigger signal after the microcontroller determines that the water level is below the safe water level and remains stable for more than 10 seconds. The sequential reset control unit is used to perform a reset in the following sequence: first stop the drainage pump, then switch to green light after a 2-second interval, and then turn off the audible and visual alarm after a 2-second interval. If the water level rises during the reset process, the reset will be interrupted immediately and the system will re-enter the drainage control state. The timed self-test unit is used to perform daily timed checks on the effectiveness of the water level sensor, communication link detection, and no-load start-up tests of the drainage pump, generate logs, and report them to the remote platform.

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