A winter pipeline drainage control device for a watering cart and a control method thereof

Abstract

This invention discloses a winter pipeline drainage control device and method for sprinkler trucks, relating to the field of drainage control technology. It includes: a controller; an attitude detection module connected to the controller for real-time acquisition of vehicle pitch and roll angles; a vehicle status detection module; multiple functional branches; multiple branch solenoid valves; multiple water pressure sensors; a compressed air source for providing purging gas; an air source solenoid valve; an environmental detection module; and a storage module. This invention, through the coordination of the attitude detection module and a pre-stored attitude-pipeline partition matrix, effectively utilizes gravitational potential energy to accelerate residual water discharge, solving the problems in existing technologies where high-level pipelines are difficult to drain due to gravity-induced water accumulation when the vehicle is not parked horizontally, and low-level pipelines are subjected to indiscriminate over-purging, resulting in air source loss. Simultaneously, high-frequency vibration pulses physically break up water films in structural dead corners such as elbows and tees, improving the reliability of sanitation vehicles operating in complex terrain environments during winter.

Description

Technical Field

[0001] This invention relates to the field of drainage control technology, and in particular to a winter drainage control device and control method for a sprinkler truck. Background Technology

[0002] As a core sanitation equipment for urban road cleaning, dust suppression, and winter snow melting, water sprinkler trucks have a water system that includes multiple functional branches such as rear spray, front flush, sprinkler, mist cannon, and water gun. After operating in low-temperature winter environments, the water remaining in the pipelines is prone to freezing and expansion, causing pipeline rupture, water pump freezing damage, and solenoid valve jamming, which directly reduces the sanitation vehicle's operational uptime and equipment lifespan. Therefore, winter pipeline drainage and antifreeze control is a key technical aspect for the safe operation of water sprinkler trucks.

[0003] Currently, most existing winter pipeline drainage control technologies for sprinkler trucks adopt a passive drainage scheme triggered by a single temperature threshold. They only collect temperature data through an ambient temperature sensor. When the temperature is lower than a fixed threshold (such as 4°C), all branch solenoid valves and compressed air sources are opened simultaneously to purge and empty the pipeline.

[0004] Due to the lack of attitude perception and adaptation mechanisms, the existing drainage scheme has defects when the vehicle is not parked horizontally. Water in the high-level functional branches is difficult to drain due to gravity, and the residual water freezes and blocks the pipes quickly at low temperatures. The low-level functional branches are indiscriminately and excessively purged, resulting in ineffective loss of the vehicle's compressed air source. At the same time, residual water will continue to accumulate in the low-lying areas of the pipeline, bends, tees and other structural dead corners, which cannot be drained by conventional purging. Eventually, freezing points will form and gradually expand, directly causing the pipeline, valve body and spraying components to freeze and crack, which will significantly increase the failure rate and maintenance cost of sanitation vehicles. Summary of the Invention

[0005] The purpose of this invention is to provide a winter pipeline drainage control device and control method for sprinkler trucks, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a winter pipeline drainage control device for a sprinkler truck, comprising:

[0007] Controller;

[0008] An attitude detection module, connected to the controller, is used to collect the vehicle's pitch and roll angles in real time.

[0009] A vehicle status detection module, connected to the controller, is used to detect the stationary state of the vehicle;

[0010] Multiple functional branch lines, including rear spray branch line, front spray branch line, shower branch line, mist cannon branch line and water gun line, each branch line is connected to the main pipeline;

[0011] Multiple branch solenoid valves are respectively installed at the inlet end of each functional branch and connected to the controller;

[0012] Multiple water pressure sensors are respectively installed at the end of each functional branch and connected to the controller;

[0013] Compressed air source, used to provide purging gas;

[0014] A gas source solenoid valve is installed between the compressed gas source and each functional branch, and is connected to the controller;

[0015] An environmental monitoring module, connected to the controller, is used to collect ambient temperature and humidity data;

[0016] The storage module, connected to the controller, is used to pre-store the attitude-pipeline partition matrix and the process control matrix. The attitude-pipeline partition matrix includes at least the opening sequence of each functional branch, the basic drainage duration, the pressure compensation coefficient, and the pulse control mode.

[0017] A method for controlling winter pipeline drainage in sprinkler trucks includes the following steps:

[0018] S1. Real-time acquisition of vehicle pitch and roll angles, and matching of the corresponding process control matrix based on the pre-stored attitude-pipeline partition matrix;

[0019] S2. According to the process control matrix, the segmented liquid phase purging is performed in the order of priority for low-level branches and delay for high-level branches. Each segment is judged by a graded threshold based on the combined change of pressure decay rate and steady-state pressure to confirm that the purging is completed.

[0020] S3. Close the solenoid valves in sequence from the low-level branch to the high-level branch, and establish a differentiated micro-positive pressure for each branch. The micro-positive pressure value of the high-level branch includes the hydrostatic pressure difference compensation based on the attitude angle.

[0021] S4. Enter the sleep inspection state, periodically detect the pressure of each branch, and perform selective gas replenishment when the monitored pressure is lower than the gas replenishment start threshold until the pressure rises back to the gas replenishment stop threshold. The gas replenishment stop threshold is higher than the gas replenishment start threshold to form a hysteresis pressure band.

[0022] S5. When the ambient temperature, humidity and vehicle stationary time all meet the preset conditions, trigger high-frequency vibration pulses in each branch to break the water film on the pipe wall.

[0023] Preferably, in step S1, the attitude-pipeline partition matrix includes at least the opening sequence of each functional branch, the basic drainage duration, the pressure compensation coefficient, and the pulse control mode. The attitude-pipeline partition matrix has five standard attitude templates pre-stored, namely, horizontal parking mode, high parking mode at the front of the vehicle, high parking mode at the rear of the vehicle, high parking mode on the left side, and high parking mode on the right side.

[0024] The primary and secondary attitudes are determined by the absolute values ​​of pitch and roll angles. Mode matching is completed by combining the attitude reference threshold and the hysteresis buffer dead zone. Switching from non-horizontal mode to horizontal mode requires that the attitude angle be lower than the hysteresis dead zone threshold.

[0025] Preferably, after matching the process control matrix in step S1, a dynamic tilt angle correction step is also included:

[0026] For the actual parking tilt angle within the range of 0-15°, a linear mapping method is used to fine-tune the basic drainage time and pressure compensation coefficient. The drainage time of the high-position branch is extended and the compensation coefficient is increased in sync with the increase of the tilt angle, while the drainage time of the low-position branch is appropriately shortened as the tilt angle increases, so as to achieve differentiated adaptation of the drainage parameters of the high and low-position branches.

[0027] Preferably, the segmented liquid phase purging in step S2 is specifically divided into three time-sequenced cycles, and each cycle sets an initial three-level threshold range for purging determination. The thresholds are calibrated based on historical operating data of the pipeline equipment and normal purging conditions.

[0028] In the first cycle, the low-level branch is opened and purged with constant high pressure. In the second cycle, the low-level branch is kept open, the middle-level branch is opened simultaneously, and the purging pressure is reduced. In the third cycle, the high-level branch is opened with a delay and purged with a gradient opening.

[0029] Real-time acquisition of branch pressure decay rate and steady-state gauge pressure to construct a joint judgment method:

[0030] If the total pressure change is greater than the threshold A, it is determined that the branch is not emptied and needs to be continuously purged.

[0031] If the change is between threshold A and threshold B, it is considered that the branch has slight water retention and enters a continuous monitoring state.

[0032] If the change is less than the threshold B, the branch is considered to be completely emptied and the current purging cycle can be terminated. Each level of cycle is connected in sequence and the lower branch remains conductive until the purging of the higher branch is started.

[0033] Preferably, the evacuation determination threshold in step S2 supports self-learning and dynamic adjustment based on historical operating data and real-time operating conditions:

[0034] When the winter drainage process of the sprinkler truck is started for the first time, the relaxed threshold range is activated, widening the difference between threshold A and threshold B;

[0035] As the number of drainage process operations increases and vehicle operating conditions become more stable, the range between threshold A and threshold B is gradually tightened.

[0036] If the purging time of a single cycle reaches the preset maximum value of the process control matrix, but the purging judgment standard is still not met, the cycle will be forcibly terminated and the next cycle will begin.

[0037] Preferably, in step S3, the hydrostatic pressure difference compensation amount for the micro-positive pressure in the high-level branch is calculated using a linear formula:

[0038] Pcomplement = 0.003 × α, where α is the vehicle pitch angle. The compensated micro-positive pressure value of the high-level branch road is higher than that of the low-level branch road, thus offsetting the hydrostatic pressure difference caused by the slope.

[0039] Preferably, after the micro-positive pressure is established in each branch in step S3, the effectiveness of the pressure holding is verified:

[0040] Maintain a slightly positive pressure for 30 seconds. If the pressure drop in the branch is less than 0.005 MPa, the air seal is considered qualified. If the pressure drop exceeds the standard, mark the pipeline as leaking and trigger the vehicle warning.

[0041] Preferably, in step S4, the inspection cycle of the dormant inspection state is 30 seconds, and each inspection is performed by momentarily opening the gas source valve to collect the branch pressure.

[0042] The pressure difference of the hysteresis pressure band is 0.005MPa. The gas replenishment process adopts a single-point directional gas replenishment mode. The fast or slow charging time is adapted according to the pressure difference. The maximum number of gas replenishment retries is 3. If the standard is still not met, the gas replenishment failure is determined.

[0043] Preferably, in step S5, the preset condition is specifically as follows:

[0044] The ambient temperature is below -5℃, the ambient humidity is above 80%, and the vehicle has been stationary for more than 10 minutes.

[0045] The high-frequency vibration pulse is controlled by a 10Hz duty cycle, with valve opening time of 50ms and valve closing time of 50ms. Each pulse lasts for 2s, and the pulse actions of each branch are staggered by 0.5s.

[0046] The technical effects and advantages of this invention are as follows:

[0047] (1) By combining the attitude detection module with the pre-stored attitude-pipeline partition matrix, and with five standard attitude templates and dynamic tilt correction, this invention can automatically match the drainage strategy according to the actual pitch and roll angles of the vehicle. Based on the reverse gravity segmented liquid phase purging process, the purging is strictly performed in the order of priority for low-level branches and delay for high-level branches, and is combined with gradient opening control (large first and small later), effectively utilizing gravitational potential energy to accelerate the discharge of residual water. This solves the problem in the prior art that when the vehicle is not parked horizontally, the high-level pipeline (such as the front flushing branch) is difficult to discharge due to gravity water storage, and the low-level pipeline (such as the rear spraying branch) is indiscriminately over-purged, causing air source loss. At the same time, the water film in the dead corners of the structure such as elbows and tees is physically broken by high-frequency vibration pulses, avoiding the accumulation and freezing of residual water in the low-lying areas of the pipeline, reducing the risk of freezing and cracking of pipelines, valves and water pumps, and improving the reliability of sanitation vehicles in winter operations in complex terrain environments.

[0048] (2) Through a graded threshold judgment mechanism (combined change in pressure decay rate and steady-state pressure) and self-learning dynamic adjustment based on historical operating data, this invention can automatically optimize the purging judgment threshold according to the actual working conditions of the pipeline (such as new / old pipeline, air tightness difference). In the early stage of vehicle use, a loose threshold is adopted to avoid misjudgment. As operating data accumulates, the threshold is gradually tightened to improve sensitivity, overcoming the defects of incomplete drainage or excessive purging caused by fixed temperature threshold or fixed pressure threshold in the prior art. With the hysteresis pressure band design (the air replenishment start threshold and stop threshold form a pressure difference buffer), the frequent start and stop of the solenoid valve near the critical pressure is effectively avoided, which not only ensures pipeline purging, but also reduces the unnecessary loss of vehicle compressed air source, and achieves a balance between antifreeze effect and energy economy;

[0049] (3) By implementing a segmented differentiated gas sealing and pressure-maintaining process, combined with the calculation of hydrostatic pressure difference compensation, this invention can automatically increase the micro-positive pressure maintenance value of the high-level branch when the high-level pipeline is parked on a slope, ensuring that the highest point of the pipeline is always in a positive pressure state. This solves the problem in the prior art where negative pressure is formed in the high-level pipeline due to changes in posture, and the intake of cold and humid air from the outside causes condensation on the pipe wall and corrosion of the inner wall. Through the dormant inspection state and single-point directional gas replenishment mode, pressure inspection is performed at a cycle of 30 seconds. Only branches below the gas replenishment start threshold are selectively fast or slow charged, and a 3-retry mechanism is set up. This ensures long-term airtightness while avoiding continuous consumption of gas source, extending the service life of the pipeline system and reducing maintenance costs. Attached Figure Description

[0050] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention, but do not constitute a limitation thereof. In the drawings:

[0051] Figure 1This is a schematic diagram of the drainage control device of the present invention;

[0052] Figure 2 This is a control module framework diagram of the present invention;

[0053] Figure 3 This is a flowchart of the drainage control method of the present invention;

[0054] Figure 4 This is the logic diagram of the three-stage segmented liquid phase purging of the present invention.

[0055] In the attached diagram: 100, compressed air source; 200, water pump; 300, functional branch. Detailed Implementation

[0056] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0057] This invention provides, for example Figures 1-4 The present invention relates to a winter pipeline drainage control device for a sprinkler truck and its control method.

[0058] Example 1: A winter drainage control device for a sprinkler truck, comprising:

[0059] Controller;

[0060] An attitude detection module, connected to the controller, is used to collect the vehicle's pitch and roll angles in real time.

[0061] A vehicle status detection module, connected to the controller, is used to detect the stationary state of the vehicle;

[0062] Multiple functional branches 300, including rear spray branch, front spray branch, shower branch, mist cannon branch and water gun branch, each branch is connected to the main pipeline;

[0063] Multiple branch solenoid valves are respectively installed at the inlet end of each functional branch 300 and connected to the controller;

[0064] Multiple water pressure sensors are respectively installed at the end of each functional branch 300 and connected to the controller;

[0065] Compressed air source 100 is used to provide purging gas;

[0066] An air source solenoid valve is installed between the compressed air source 100 and each functional branch 300, and is connected to the controller;

[0067] An environmental monitoring module, connected to the controller, is used to collect ambient temperature and humidity data;

[0068] The storage module, connected to the controller, is used to pre-store the attitude-pipeline partition matrix and the process control matrix. The attitude-pipeline partition matrix includes at least the opening sequence, basic drainage duration, pressure compensation coefficient and pulse control mode of each functional branch 300.

[0069] The controller is configured to: match the process control matrix based on the data collected by the attitude detection module, control the opening and closing sequence and opening degree of each branch solenoid valve and the gas source solenoid valve, and perform segmented liquid phase purging, segmented differentiated gas seal pressure maintenance and inspection and gas replenishment operations.

[0070] Example 2: A method for controlling winter pipeline drainage in a sprinkler truck, characterized by the following steps:

[0071] Step S1: Obtain the vehicle pitch angle and roll angle in real time, and match the corresponding process control matrix based on the pre-stored attitude-pipeline partition matrix;

[0072] In some implementations, the attitude detection module uses a dual-axis tilt sensor or a MEMS-based attitude measurement unit, which is installed at the midpoint of the longitudinal beam of the vehicle frame to collect the vehicle's pitch angle θ (positive for front-end elevation and negative for rear-end elevation) and roll angle φ (positive for left-side elevation and negative for right-side elevation) relative to the horizontal plane in real time. The sampling frequency is set to 10Hz, and road surface micro-vibration interference is eliminated by moving average filtering.

[0073] The attitude-pipeline partition matrix is ​​stored in the non-volatile storage area of ​​the storage module using a two-dimensional index data structure. The first dimension index is the attitude mode code, and the second dimension index is the functional branch (300) identifier. The attitude-pipeline partition matrix contains at least five standard attitude templates, namely, horizontal parking mode, front high parking mode, rear high parking mode, left high parking mode, and right high parking mode.

[0074] For example, the data structure definition of the attitude-pipeline partition matrix is ​​shown in Table 1:

[0075] Table 1. Attitude-Pipeline Partition Matrix Data Structure

[0076] Horizontal parking |θ|≤2° |φ|≤2° After spray: 1 / 15s beat Forward movement: 3 / 20s 1.0 / 1.0 High front of the car 2°<θ≤15° |φ|≤2° After spray: 1 / 18s beat Forward sprint: 3 / 28s 1.2 / 1.4 rear high -15°≤θ<-2° |φ|≤2° After spray: 1 / 12s beat Forward movement: 3 / 24s 0.8 / 1.1 left side high |θ|≤2° 2°<φ≤15° Left side: 1 / 16s beat Right side: 3 / 22s 1.1 / 1.3 Right side high |θ|≤2° -15°≤φ<-2° Right side: 1 / 16s beat Left side: 3 / 22s 1.1 / 1.3

[0077] The attitude reference thresholds are set to pitch ±2° and roll ±2°; the hysteresis buffer dead zone is set to ±0.5°. The controller determines the primary and secondary attitudes based on the absolute values ​​of the pitch and roll angles: when |θ|>|φ|, the pitch angle takes precedence; when |φ|>|θ|, the roll angle takes precedence. Switching from non-horizontal mode to horizontal mode requires the absolute value of the attitude angles to be below 0.5° for at least 5 seconds to prevent frequent mode switching caused by attitude jitter.

[0078] Furthermore, after matching the process control matrix in step S1, a dynamic tilt angle correction step is also included. For the actual parking tilt angle within the range of 0-15°, a linear mapping method is used to fine-tune the foundation drainage time and pressure compensation coefficient. The correction formula is:

[0079]

[0080] in, This is the corrected drainage time. Basic drainage duration, The branch location coefficient is set as follows: +0.3 for high-position branches, -0.2 for low-position branches, and 0 for mid-position branches. For example, when the vehicle is in a high-cab parking mode with a pitch angle θ = 8°, the basic drainage time of the forward-rushing branch (high-position) is corrected from 20s to 20×(1+0.3×8 / 15) = 23.2s, and the basic drainage time of the rear-spraying branch (low-position) is corrected from 15s to 15×(1−0.2×8 / 15) = 13.4s. The drainage time of the high-position branch is extended and the compensation coefficient is increased in tandem with the increase of the tilt angle, while the drainage time of the low-position branch is appropriately shortened with the increase of the tilt angle, thus achieving differentiated adaptation of the drainage parameters of the high and low-position branches.

[0081] Step S2: According to the process control matrix, perform segmented liquid phase purging in the order of priority for low-level branches and delay for high-level branches;

[0082] In some implementations, the segmented liquid phase purging is specifically divided into three time-sequenced cycles, and an initial three-level threshold range is set for the emptying determination in each cycle. The process control matrix pre-stores cycle control parameters for each attitude mode, including:

[0083] Initial three-level threshold range: Define threshold A (threshold for determining incomplete drainage) and threshold B (threshold for determining slight water retention), with initial values ​​set at 0.015MPa and 0.005MPa respectively;

[0084] Cyclic pressure thresholds: First cycle high-pressure purging pressure range 0.25-0.30MPa, second cycle medium-pressure purging pressure range 0.15-0.20MPa, third cycle gradient opening starting pressure 0.10MPa, ending pressure 0.05MPa;

[0085] Maximum purge duration: The maximum duration of a single beat is 60s for the first beat, 90s for the second beat, and 120s for the third beat.

[0086] Real-time data collection of branch pressure decay rate and steady-state gauge pressure is used to construct a joint judgment method. The comprehensive pressure change... Calculated using a weighted summation method:

[0087] in, The pressure decay rate (unit: MPa / s) is calculated from the pressure difference between the current time and the previous time (sampling interval 100ms). This represents the steady-state gauge pressure (unit: MPa), which is the average pressure value after the current cycle lasts for 5 seconds. and The weighting coefficients are 0.6 and 0.4, respectively, representing the relative importance of dynamic pressure changes and static steady state in the venting determination.

[0088] The logical flow for determining the hierarchical threshold is as follows:

[0089] like If the threshold A (0.015MPa) is reached, the branch is determined to be not emptied and requires continuous purging.

[0090] If the threshold B (0.005MPa) ≤ If the water level is ≤ threshold A (0.015MPa), it is considered that there is slight water accumulation in the branch and the branch enters continuous monitoring mode, extending the current cycle time by 30 seconds.

[0091] like If the pressure is less than the threshold B (0.005MPa), the branch is considered completely emptied and the current purging cycle can be terminated.

[0092] Each cycle is sequentially connected, with the lower-level branch remaining open until the higher-level branch starts purging. Specifically, in the first cycle, the lower-level branch (such as the rear spray branch) is opened and purged with a constant high pressure of 0.28 MPa; in the second cycle, the lower-level branch is kept open, the middle-level branch (such as the shower branch) is opened simultaneously, and the purging pressure is reduced to 0.18 MPa; in the third cycle, the higher-level branch (such as the front flush branch) is opened with a delay and purging is carried out with a gradient opening, the opening of the air source solenoid valve is gradually reduced from 50% to 20%, and the corresponding pressure is gradually reduced from 0.12 MPa to 0.06 MPa, effectively utilizing gravitational potential energy to accelerate the discharge of residual water.

[0093] Furthermore, the evacuation judgment threshold in step S2 supports self-learning dynamic adjustment based on historical operating data and real-time operating conditions. When the winter drainage process of the sprinkler truck is started for the first time, a more lenient threshold range is activated, with threshold A set to 0.020 MPa and threshold B set to 0.008 MPa, widening the difference between the two to avoid misjudgments caused by the unstable airtightness of the new pipeline. The system records the pressure decay curve for each drainage process and calculates the actual evacuation time. Compared with theoretical emptying time deviation rate As the number of drainage process operations increases (more than 20 times) and vehicle operating conditions stabilize, if δ is less than 10% for three consecutive times, threshold A is gradually tightened to 0.012 MPa and threshold B to 0.004 MPa to improve the sensitivity of venting judgment. If the purging time of a single cycle reaches the preset maximum value of the process control matrix but the venting judgment standard is still not met, the cycle is forcibly terminated and the next cycle begins to prevent excessive consumption of gas source.

[0094] Step S3: Close the solenoid valves segment by segment according to the timing from the low-level branch to the high-level branch, and establish differentiated micro-positive pressure for each branch;

[0095] In some implementations, the hydrostatic pressure differential compensation for the slightly positive pressure in the elevated branch is calculated using a linear formula. , where α is the vehicle pitch angle (unit: degrees). The derivation of this formula is based on the principle of hydrostatic equilibrium in fluid dynamics:

[0096] When a vehicle is parked on a slope with a pitch angle α, the relationship between the geometric elevation difference Δh between the higher and lower branch roads and the pitch angle is as follows:

[0097] Δh=L×sin(α)≈L×α×(π / 180)

[0098] Where L is the horizontal distance between the front and rear side roads of the vehicle (approximately 2.0m for a typical sprinkler truck). After conversion, Δh (cm) ≈ 3.5 × α (°).

[0099] According to the hydrostatic pressure formula P=ρgh, where ρ is the density of water (1000kg / m³), g is the acceleration due to gravity (9.8m / s²), and h is the height of the water column, the calculation yields:

[0100] P=1000×9.8×(0.035×α)=343×α(Pa)≈0.000343×α(MPa)

[0101] Considering the pipeline resistance loss coefficient (approximately 8.7 times) and the engineering safety margin, and taking an adjustment factor of 0.003 MPa / °, the compensation formula is obtained. The compensated high-level branch micro-positive pressure value is set to 0.015+. (MPa), the slightly positive pressure value of the low - pressure branch maintains 0.015 MPa, ensuring that the highest point of the pipeline is always in a positive pressure state to offset the hydrostatic pressure difference generated by the slope.

[0102] After the slightly positive pressure of each branch is established, perform the verification of the pressure - holding effectiveness. The controller closes the branch solenoid valve, maintains the slightly positive pressure state for 30 s, and collects the branch pressure drop through the water pressure sensor. If <0.005 MPa, it is determined that the air seal is qualified; if ≥0.005 MPa, mark the pipeline air leakage fault and trigger the vehicle - mounted warning system to prompt the driver for maintenance.

[0103] Step S4: Enter the sleep and patrol state, periodically detect the pressure of each branch, and perform selective air replenishment when the monitored pressure is lower than the air replenishment start threshold value.

[0104] In some embodiments, the patrol cycle of the sleep and patrol state is set to 30 s, and the branch pressure is collected by instantaneously opening the air source valve for 50 ms each time during the patrol. The pressure difference of the hysteresis pressure band is set to 0.005 MPa. The specific engineering implementation is as follows:

[0105] Air replenishment start threshold value = 0.010 MPa;

[0106] Air replenishment stop threshold value = 0.015 MPa;

[0107] Form a hysteresis pressure band = − = 0.005 MPa.

[0108] The air replenishment process adopts a single - point directional air replenishment mode: when the pressure of a certain branch is lower than the controller only opens the solenoid valve corresponding to that branch and the air source solenoid valve, and adapts the fast - charge or slow - charge duration according to the pressure difference size:

[0109] If the pressure difference ΔP > 0.008 MPa, adopt the fast - charge mode, and the air source solenoid valve is opened for duration = 200 ms;

[0110] If the pressure difference is such that 0.003 MPa ≤ ΔP ≤ 0.008 MPa, adopt the slow - charge mode, and the air source solenoid valve is opened for duration = 100 ms.

[0111] The upper limit of the air replenishment retry times is set to 3 times. If the pressure still does not rise above Pstop after 3 consecutive air replenishments, it is determined that there is an air replenishment fault in that branch, trigger a continuous beeping alarm and record the fault code to avoid the frequent start - stop of the solenoid valve near the critical pressure.

[0112] Step S5: When the ambient temperature, humidity and vehicle stationary time all meet the preset conditions, trigger the high-frequency vibration pulse of each branch to break the water film on the pipe wall.

[0113] In some implementations, the preset conditions specifically include: ambient temperature below -5°C, ambient humidity above 80%, and vehicle stationary time exceeding 10 minutes. The hardware implementation of the high-frequency vibration pulse relies on a high-speed response solenoid valve drive circuit. The controller controls the branch solenoid valve via a PWM (Pulse Width Modulation) signal, with a frequency set to 10Hz (period 100ms) and a duty cycle of 50%, i.e., valve opening 50ms and valve closing 50ms. The solenoid valve drive circuit employs a MOSFET fast switching scheme, with a switching response time of less than 5ms, ensuring a steep leading edge of the pulse waveform.

[0114] Each pulse lasts for 2 seconds (i.e., 20 complete cycles), and the pulse actions of each branch are staggered by 0.5 seconds. The specific timing is as follows:

[0115] t=0s: Start-up pulse of the subsequent spray branch;

[0116] t=0.5s: Start pulse of the forward impulse branch;

[0117] t=1.0s: Shower head branch start pulse;

[0118] t=1.5s: Fog cannon branch start pulse;

[0119] t=2.0s: Water gun circuit start pulse.

[0120] Peak-shifting control avoids the instantaneous drop in air source pressure caused by the simultaneous opening and closing of multiple branches, ensuring that the pressure of the compressed air source (100) remains stable within the working range of 0.4-0.6MPa, and breaking the water film in structural dead corners such as elbows and tees through physical vibration.

[0121] Example 3: Drainage control in horizontal parking mode: When the attitude detection module detects that the pitch angle |θ|≤2° and the roll angle |φ|≤2°, the controller matches the horizontal parking mode (code 0x01). Based on the process control matrix, the following steps are executed:

[0122] Step S1: Retrieve the activation sequence corresponding to the horizontal parking mode. The activation sequence of the rear spray branch (low position) is beat 1, the shower branch is beat 2, and the front flush branch (high position) is beat 3; the basic drainage time is 15s, 18s, and 20s respectively; the pressure compensation coefficient is 1.0 for all of them.

[0123] Step S2: After the first beat starts, open the rear sprinkler branch solenoid valve and the air source solenoid valve, and purge with a constant high pressure of 0.28 MPa. Real-time collect the water pressure at the end of the rear sprinkler branch, and calculate the comprehensive pressure change amount ΔPcomp = 0.6×∣dP / dt∣ + 0.4×Pss. If ΔPcomp < 0.005 MPa, determine that the rear sprinkler branch is emptied, keep the rear sprinkler branch solenoid valve open, and enter the second beat.

[0124] In the second beat, synchronously open the shower branch solenoid valve and reduce the purge pressure to 0.18 MPa. Monitor the pressure change of the shower branch. If the evacuation standard is reached (ΔPcomp < 0.005 MPa), keep the rear sprinkler and shower branches conducting and enter the third beat.

[0125] How to use the pressure and flow rate sensors to measure the pressure and flow rate of the fluid in the pipeline. In the third beat, delay the opening of the front flush branch solenoid valve and perform gradient opening purge: the opening of the air source solenoid valve gradually decreases from 50% to 20%, and the corresponding pressure gradually decreases from 0.12 MPa to 0.06 MPa until ΔPcomp < 0.005 MPa in the front flush branch.

[0126] Step S3: Close the solenoid valves section by section in the time sequence from the low-position branch to the high-position branch. First, close the rear sprinkler branch solenoid valve to establish a slight positive pressure of 0.015 MPa; secondly, close the shower branch to establish a slight positive pressure of 0.015 MPa; finally, close the front flush branch to establish a slight positive pressure of 0.015 MPa. Keep the pressure for 30 s to verify the airtightness. If the pressure drop is less than 0.005 MPa, it is determined to be qualified.

[0127] Step S4: Enter the sleep patrol. Detect the pressure of each branch every 30 s. If the pressure of a certain branch drops to 0.010 MPa, trigger single-point directional air replenishment, and stop fast charging or slow charging when it reaches 0.015 MPa.

[0128] Step S5: When the environmental temperature is -7°C, the humidity is 85%, and the static duration is 12 min, trigger the high-frequency tremor pulse. The rear sprinkler branch starts a 10 Hz pulse at t = 0 s and lasts for 2 s; the front flush branch starts at t = 0.5 s and lasts for 2 s to break the residual water film on the pipe wall.

[0129] Example 4: Dynamic correction control in the front-of-vehicle high parking mode (θ = 8°): When the attitude detection module detects that the pitch angle θ = 8° (front of the vehicle high) and the roll angle |φ| ≤ 2°, the controller matches the front-of-vehicle high parking mode (encoding 0x02). In step S1, according to the dynamic inclination correction formula:

[0130] The basic drainage duration T0 of the rear sprinkler branch (low position) is 15 s, the correction coefficient Kθ = -0.2, and the corrected duration Tadj = 15×(1 - 0.2×8 / 15) = 13.4 s, rounded to 13 s;

[0131] The drainage time of the foundation of the forward branch road (high position) is T0=20s, the correction coefficient Kθ=+0.3, and the corrected time Tadj=20×(1+0.3×8 / 15)=23.2s, which is rounded to 23s.

[0132] The pressure compensation coefficient of the forward branch is 1.4, the static pressure difference compensation P_compensation = 0.003 × 8 = 0.024 MPa, and the micro-positive pressure setting value = 0.015 + 0.024 = 0.039 MPa.

[0133] In step S2, during the segmented liquid phase purging process, the high-level branch (forward flushing) is delayed until the third segment to open, and the upper limit of the purging pressure gradient is increased to 0.15 MPa to overcome gravity-induced water retention.

[0134] In step S3, during the segmented air sealing, a slight positive pressure of 0.039 MPa is established in the forward-flowing branch to offset the approximately 0.024 MPa hydrostatic pressure difference generated by the 8° slope, ensuring that the highest point of the branch maintains positive pressure.

[0135] In step S4, the hysteresis pressure band is adjusted for the forward-rushing branch as follows: the gas replenishment start threshold is 0.034MPa, the stop threshold is 0.039MPa, and a pressure difference buffer of 0.005MPa is maintained to prevent frequent start and stop of gas replenishment.

[0136] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A winter drainage control device for a sprinkler truck, characterized in that, include: Controller; An attitude detection module, connected to the controller, is used to collect the vehicle's pitch and roll angles in real time. A vehicle status detection module, connected to the controller, is used to detect the stationary state of the vehicle; Multiple functional branch lines (300) include rear spray branch line, front spray branch line, shower branch line, mist cannon branch line and water gun line, and each branch line is connected to the main pipeline; Multiple branch solenoid valves are respectively installed at the inlet end of each functional branch (300) and connected to the controller; Multiple water pressure sensors are respectively installed at the end of each functional branch (300) and connected to the controller; Compressed air source (100) is used to provide purging gas; An air source solenoid valve is installed between the compressed air source (100) and each functional branch (300) and is connected to the controller; An environmental monitoring module, connected to the controller, is used to collect ambient temperature and humidity data; The storage module, connected to the controller, is used to pre-store the attitude-pipeline partition matrix and the process control matrix. The attitude-pipeline partition matrix includes at least the opening sequence, basic drainage duration, pressure compensation coefficient and pulse control mode of each functional branch (300).

2. The method for controlling winter pipeline drainage of a sprinkler truck according to claim 1, characterized in that, Includes the following steps: S1. Real-time acquisition of vehicle pitch and roll angles, and matching of the corresponding process control matrix based on the pre-stored attitude-pipeline partition matrix; S2. According to the process control matrix, the segmented liquid phase purging is performed in the order of priority for low-level branches and delay for high-level branches. Each segment is judged by a graded threshold based on the combined change of pressure decay rate and steady-state pressure to confirm that the purging is completed. S3. Close the solenoid valves in sequence from the low-level branch to the high-level branch, and establish a differentiated micro-positive pressure for each branch. The micro-positive pressure value of the high-level branch includes the hydrostatic pressure difference compensation based on the attitude angle. S4. Enter the sleep inspection state, periodically detect the pressure of each branch, and perform selective gas replenishment when the monitored pressure is lower than the gas replenishment start threshold until the pressure rises back to the gas replenishment stop threshold. The gas replenishment stop threshold is higher than the gas replenishment start threshold to form a hysteresis pressure band. S5. When the ambient temperature, humidity and vehicle stationary time all meet the preset conditions, trigger high-frequency vibration pulses in each branch to break the water film on the pipe wall.

3. The method for controlling winter pipeline drainage of a sprinkler truck according to claim 2, characterized in that, In step S1, the attitude-pipeline partition matrix includes at least the opening sequence, basic drainage duration, pressure compensation coefficient and pulse control mode of each functional branch (300). The attitude-pipeline partition matrix has five standard attitude templates pre-stored, namely horizontal parking mode, front high parking mode, rear high parking mode, left high parking mode and right high parking mode. The primary and secondary attitudes are determined by the absolute values ​​of pitch and roll angles. Mode matching is completed by combining the attitude reference threshold and the hysteresis buffer dead zone. Switching from non-horizontal mode to horizontal mode requires that the attitude angle be lower than the hysteresis dead zone threshold.

4. The method for controlling winter pipeline drainage of a sprinkler truck according to claim 2, characterized in that, After matching the process control matrix in step S1, the process also includes a dynamic tilt correction step: For the actual parking tilt angle within the range of 0-15°, a linear mapping method is used to fine-tune the basic drainage time and pressure compensation coefficient. The drainage time of the high-position branch is extended and the compensation coefficient is increased in sync with the increase of the tilt angle, while the drainage time of the low-position branch is appropriately shortened as the tilt angle increases, so as to achieve differentiated adaptation of the drainage parameters of the high and low-position branches.

5. The method for controlling winter pipeline drainage of a sprinkler truck according to claim 2, characterized in that, The segmented liquid phase purging described in step S2 is specifically divided into three time-sequenced cycles, and each cycle sets an initial three-level threshold range for purging determination. The thresholds are calibrated based on historical operating data of the pipeline equipment and normal purging conditions. In the first cycle, the low-level branch is opened and purged with constant high pressure. In the second cycle, the low-level branch is kept open, the middle-level branch is opened simultaneously, and the purging pressure is reduced. In the third cycle, the high-level branch is opened with a delay and purged with a gradient opening. Real-time acquisition of branch pressure decay rate and steady-state gauge pressure to construct a joint judgment method: If the total pressure change is greater than the threshold A, it is determined that the branch is not emptied and needs to be continuously purged. If the change is between threshold A and threshold B, it is considered that the branch has slight water retention and enters a continuous monitoring state. If the change is less than the threshold B, the branch is considered to be completely emptied and the current purging cycle can be terminated. Each level of cycle is connected in sequence and the lower branch remains conductive until the purging of the higher branch is started.

6. The method for controlling winter pipeline drainage of a sprinkler truck according to claim 5, characterized in that, The venting determination threshold in step S2 supports self-learning and dynamic adjustment based on historical operating data and real-time operating conditions. When the winter drainage process of the sprinkler truck is started for the first time, the relaxed threshold range is activated, widening the difference between threshold A and threshold B; As the number of drainage process operations increases and vehicle operating conditions become more stable, the range between threshold A and threshold B is gradually tightened. If the purging time of a single cycle reaches the preset maximum value of the process control matrix, but the purging judgment standard is still not met, the cycle will be forcibly terminated and the next cycle will begin.

7. The method for controlling winter pipeline drainage of a sprinkler truck according to claim 2, characterized in that, In step S3, the hydrostatic pressure difference compensation for the micro-positive pressure in the high-level branch is calculated using a linear formula: Pcomplement = 0.003 × α, where α is the vehicle pitch angle. The compensated micro-positive pressure value of the high-level branch road is higher than that of the low-level branch road, thus offsetting the hydrostatic pressure difference caused by the slope.

8. The method for controlling winter pipeline drainage of a sprinkler truck according to claim 2, characterized in that, After the micro-positive pressure is established in each branch in step S3, the effectiveness of the pressure holding is verified: Maintain a slightly positive pressure for 30 seconds. If the pressure drop in the branch is less than 0.005 MPa, the air seal is considered qualified. If the pressure drop exceeds the standard, mark the pipeline as leaking and trigger the vehicle warning.

9. The method for controlling winter pipeline drainage of a sprinkler truck according to claim 2, characterized in that, In step S4, the inspection cycle of the dormant inspection state is 30 seconds, and each inspection is carried out by momentarily opening the gas source valve to collect the branch pressure. The pressure difference of the hysteresis pressure band is 0.005MPa. The gas replenishment process adopts a single-point directional gas replenishment mode. The fast or slow charging time is adapted according to the pressure difference. The maximum number of gas replenishment retries is 3. If the standard is still not met, the gas replenishment failure is determined.

10. The method for controlling winter pipeline drainage of a sprinkler truck according to claim 2, characterized in that, In step S5, the preset conditions are specifically as follows: The ambient temperature is below -5℃, the ambient humidity is above 80%, and the vehicle has been stationary for more than 10 minutes. The high-frequency vibration pulse is controlled by a 10Hz duty cycle, with valve opening time of 50ms and valve closing time of 50ms. Each pulse lasts for 2s, and the pulse actions of each branch are staggered by 0.5s.

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