A digital sludge discharge system for a sedimentation basin and a control method

Abstract

The application discloses a kind of sedimentation tank digital sludge discharge systems and control method, belong to water purification, sewage treatment technical field, system includes: optical detection module, control module and electric valve;The optical detection module is used to apply detection light to the measured object and collect light intensity signal, while self-cleaning;The control module is used to receive the light intensity signal, by the analysis of light transmittance and time sequence integration, construct light transmission time sequence curve, by the trend analysis to the light transmission time sequence curve, divide sludge section, mixed transition section, and carry out the differentiated control of stage, while after current sludge discharge period is executed, evaluate current sludge discharge effect, based on sludge discharge effect self-adapting adjustment sludge discharge period;The electric valve is used to receive the control signal of the control module, and carry out the on-off control of sludge discharge pipeline.

Description

Technical Field

[0001] This invention belongs to the field of water purification and wastewater treatment technology, and relates to a digital sludge discharge system and control method for sedimentation tanks. Background Technology

[0002] As a core unit in water treatment processes, sedimentation tanks are mainly used to remove suspended particulate matter, sludge, and other impurities from water, ensuring the stable operation of subsequent water treatment processes. Sludge removal is a critical operation in the sedimentation tank process, the purpose of which is to promptly remove the sludge deposited at the bottom of the tank to prevent sludge accumulation from affecting the treatment efficiency of the sedimentation tank and the quality of the effluent.

[0003] Chinese Patent CN117326680B discloses an adaptive control wastewater sludge discharge system and control method. The wastewater sludge discharge system includes a sedimentation device, a sludge discharge pump, and a control cabinet. The sedimentation device is connected to a wastewater inlet. The sedimentation device has multiple built-in pollutant detection devices. The multiple pollutant detection devices are used to obtain at least one wastewater index value of the wastewater entering the sedimentation device. The control cabinet communicates with the multiple pollutant detection devices. Based on at least one wastewater index value, the control cabinet controls a first operating state of the sedimentation device and / or controls a second operating state of the sludge discharge pump.

[0004] Although existing technologies dynamically adjust sludge discharge and sedimentation devices by monitoring influent indicators in real time, they do not consider the time lag characteristics of the sewage sedimentation process. Specifically, there is a significant time difference between changes in influent water quality and the large-scale settling and gradual rise of sludge in the tank. Relying solely on real-time changes and trends in influent indicators to adjust sludge discharge can easily lead to untimely or excessive sludge discharge. Furthermore, the lack of real-time monitoring of sludge concentration and moisture content in the discharged sludge makes it impossible to determine whether the discharged material is sludge or water, resulting in an uncertainty about the effectiveness of the sludge discharge operation. This can easily lead to low solids content in the discharged sludge, increasing the burden on subsequent sludge dewatering and failing to ensure that the accumulated sludge is truly cleared. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a digital sludge removal system and control method for sedimentation tanks. This system directly collects light transmission information of the medium within the pipeline through optical detection, manages the sludge removal process in stages to distinguish between sludge and clean water, and adaptively adjusts the sludge removal strategy after the cycle ends. This accurately judges the effectiveness of sludge removal and avoids sludge accumulation and excessive drainage.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A digital sludge removal system for sedimentation tanks includes: an optical detection module, a control module, and an electric valve;

[0008] The optical detection module is used to apply detection light to the object under test and collect light intensity signals, while also performing self-cleaning.

[0009] The control module is used to receive the light intensity signal, construct a light transmittance time sequence curve by analyzing the light transmittance and integrating the time sequence, divide the light transmittance time sequence curve into sludge segment and mixing transition segment by performing trend analysis, and perform differentiated control in stages. At the same time, after the current sludge discharge cycle is completed, the current sludge discharge effect is evaluated, and the sludge discharge cycle is adaptively adjusted based on the sludge discharge effect.

[0010] The electric valve is used to receive control signals from the control module and to control the opening and closing of the sludge discharge pipeline.

[0011] Specifically, the optical detection module is configured with dual optical paths, including a main optical path and a reference optical path;

[0012] The main optical path uses a mixture of sludge and clean water as the object under test to acquire the light intensity signal that penetrates the object under test.

[0013] The reference optical path uses a medium with constant transmittance as a reference object to obtain a reference signal that penetrates the reference object.

[0014] Specifically, the control module includes a parsing unit, a perception and decision-making unit, and a self-testing unit;

[0015] The analysis unit uses the reference signal to calibrate and compensate the light intensity signal, and performs transmittance analysis on the compensated light intensity signal, and constructs a transmittance time series curve by combining the time series.

[0016] The sensing and decision-making unit is used to perform trend analysis on the light transmission time curve, divide it into sludge segment and mixing transition segment. For the sludge segment, a valve opening signal is generated. For the mixing transition segment, forced evacuation is performed according to the calculated delayed valve closing time. After the delayed valve closing time is reached, the maximum timeout is calculated according to the critical light transmission threshold, and a delayed valve closing signal is generated.

[0017] The self-testing unit is used to store the operation process data of each sludge discharge cycle. Before each sludge discharge cycle starts, it performs a micro-stroke self-test by controlling the electric valve. After the sludge discharge cycle is completed, it adaptively adjusts the next sludge discharge cycle by the effective sludge discharge time.

[0018] Specifically, calibrating and compensating the light intensity signal using the reference signal includes:

[0019] The light intensity signal and the reference signal are preprocessed.

[0020] Retrieve the initial reference light intensity of the reference optical path described in the initialization phase;

[0021] For the preprocessed reference signal, the reference light intensity at each sampling time is retrieved, and the relative attenuation coefficient at each sampling time is obtained by the ratio of the reference light intensity to the initial reference light intensity.

[0022] For the preprocessed light intensity signal, retrieve the light intensity value at each sampling time, and obtain the equivalent light intensity value by the ratio of the light intensity value to the corresponding relative attenuation coefficient;

[0023] All equivalent light intensity values ​​are integrated according to the sampling time sequence to obtain the calibration light intensity signal.

[0024] Specifically, constructing the light transmission time sequence curve includes:

[0025] Using the sludge discharge cycle as the trigger node, the initial light intensity of the medium in the main optical path is obtained after each self-cleaning is completed.

[0026] Based on the sampling time, the equivalent light intensity in the calibration light intensity signal is traversed, and the transmittance of the corresponding sampling point is obtained by the ratio of the equivalent light intensity to the initial light intensity of sludge discharge.

[0027] The transmittance is arranged according to the sampling time and serialized to generate discrete data pairs containing the correspondence between sampling time and transmittance.

[0028] Consistency checks are performed on all discrete data pairs based on the sampling interval, and linear interpolation is used to fill in missing sampling points caused by data transmission packet loss.

[0029] A smooth light transmission time curve is constructed by using time as the horizontal axis and light transmittance as the vertical axis through continuous fitting.

[0030] Specifically, the sludge section and the mixing transition section are divided into:

[0031] The transmittance is continuously acquired starting from the sludge discharge start time, and at this time it is assumed to be the sludge section;

[0032] Once the timing reaches the initial duration of sludge discharge, a differential noise sequence is constructed by performing a first-order difference operation on the light transmission time sequence curve.

[0033] Taking the continuous consistent sign of the difference transmittance as in-phase change, the differential noise sequence is traversed to segment multiple in-phase change segments. The lower bound of the window is set by the mean and multiple calculation of the number of sampling points.

[0034] Set the upper limit of the window based on the rated response time of the electric valve switch;

[0035] Calculate the real-time standard deviation of light transmittance, combine it with the standard deviation of light transmittance of clear water and the lower limit of the window, set the number of basic window points, and perform boundary truncation;

[0036] Based on the light transmission time series curve, multiple data subsets were divided, and the instantaneous rate of change was calculated using least squares linear fitting.

[0037] If continuous If all instantaneous change rates are greater than the rising switching threshold, it is determined that the sludge section is being switched to the mixed transition section.

[0038] For the mixed transition section, if continuous If all instantaneous change rates are less than the fallback switching threshold, it is determined that the system will fall back to sludge.

[0039] Specifically, generating the delayed valve-closing signal includes:

[0040] When determining the continuity of the mixed transition section Calculate the average rate of rise based on the instantaneous rate of change;

[0041] The transmittance at the switching moment is retrieved, and the difference is calculated by combining it with the critical transmittance threshold to obtain the effective transmittance difference;

[0042] Based on the instantaneous change rate of the sludge section, historical statistical data is obtained, and the benchmark fluctuation value is calculated using the standard of a single sludge discharge cycle.

[0043] Based on the standard deviation of the instantaneous change rate within the initial sludge discharge time and the benchmark fluctuation value, the fluctuation correction coefficient is calculated. Combined with the effective light transmittance difference and the average lifting rate, the delayed valve closing time is calculated, and a forced evacuation countdown is performed.

[0044] After the forced empty countdown reaches zero, perform a multi-branch decision.

[0045] When continuous When the light transmittance is greater than the critical light transmittance threshold and the instantaneous rate of change maintains a non-negative upward trend, the operating condition is deemed to be in compliance, and a valve closing signal is generated.

[0046] Starting with the countdown to zero for forced evacuation, a waiting period is set. If the operating condition is not deemed to meet the standard after the waiting period reaches the maximum safe overtime period, a regular early warning signal is generated.

[0047] Specifically, the micro-travel self-check steps include:

[0048] Before the formal sludge discharge, a micro-stroke opening command is issued to the electric valve, driving the electric valve to move from the fully closed position to the micro-stroke opening degree and maintain the set self-check time, and then a micro-stroke closing command is issued.

[0049] Throughout the entire process of the electric valve performing micro-stroke actions, the transmittance of the main optical path is continuously acquired to construct a self-test transmittance sequence;

[0050] The maximum fluctuation amplitude is obtained by performing range calculation on the self-test transmittance sequence;

[0051] Obtain the baseline fluctuation range and determine the on / off status;

[0052] If the maximum fluctuation amplitude is within the benchmark fluctuation range, a self-inspection qualified signal is generated, triggering the sludge discharge process;

[0053] If the maximum fluctuation amplitude is not within the benchmark fluctuation range, the self-check is determined to be abnormal, and a self-check early warning signal is generated.

[0054] Specifically, adaptive adjustment of the next sludge discharge cycle includes:

[0055] Acquire data from the entire sludge removal process, align it with the time frame, and generate a sludge removal dataset.

[0056] Extract the sludge duration from the sludge discharge dataset as the effective sludge discharge duration;

[0057] Obtain the standard range for sludge discharge and conduct a single-cycle sludge discharge effect evaluation to determine whether the current round of sludge discharge is qualified.

[0058] The effective sludge discharge time for which sludge discharge is deemed qualified is obtained. The difference between the start times of two adjacent sludge discharge cycles is used as the settling time. The settling time is used as the independent variable and the effective sludge discharge time is used as the dependent variable. The sludge accumulation rate is obtained by fitting the data using least squares linear regression.

[0059] If the sludge accumulation rate is greater than the baseline sludge accumulation rate, then shorten the initial sludge discharge time and extend the interval for starting the next round of sludge discharge; otherwise, extend the initial sludge discharge time and shorten the interval for starting the next round of sludge discharge.

[0060] A digital sludge discharge control method for sedimentation tanks includes:

[0061] Initialize operating parameters. Once the sludge discharge cycle is reached or a sludge discharge command is received, perform a micro-stroke self-check by controlling the electric valve. Sludge discharge is only allowed when the micro-stroke self-check is qualified.

[0062] The light source continuously emits detection light into the object under test inside the transparent observation tube, and the light intensity signal of the object under test is collected in real time based on the light sensor. Through calibration and compensation of the reference signal and transmittance analysis, a transmittance time series curve is constructed.

[0063] By analyzing the trend of the light transmittance time curve, the sludge section and the mixing transition section are divided.

[0064] For the sludge section, a valve opening signal is generated; for the mixing transition section, a forced evacuation countdown is performed by delaying the valve closing time, and a maximum timeout is performed by combining the critical light transmittance threshold to generate a delayed valve closing signal.

[0065] After the sludge discharge is completed, the sludge discharge effect is evaluated, and the next sludge discharge cycle is adaptively adjusted based on the sludge accumulation rate of multiple consecutive sludge discharge cycles.

[0066] The beneficial effects of this invention are:

[0067] By directly collecting light intensity data from the medium flowing through the sludge discharge pipeline, the system captures the light transmittance characteristics of the discharged medium in real time and directly monitors the actual sludge composition at the medium outlet to determine the true effectiveness of the sludge discharge operation. This avoids ineffective drainage caused by blindly opening and closing valves. Simultaneously, the system constructs a light transmittance time-series curve based on the collected light intensity signals. Based on the time-series trend characteristics, the entire sludge discharge process is divided into a sludge section and a mixing transition section for differentiated management. In the sludge section, the valves are forcibly fully opened to ensure stable discharge of the sludge accumulated at the bottom of the tank. In the transition section, the forced emptying time is dynamically set based on the light transmittance change rate, and valve closure is finally achieved by combining this with threshold judgment. This time-series layered constraint avoids accidental valve closure and incomplete sludge discharge caused by instantaneous medium disturbances, or continuous meaningless overflow. The system addresses the issue of water discharge by eliminating the inherent settling time lag bias in influent index control methods. It adapts to the process characteristics of sludge settling lag in sedimentation tanks, integrates the entire process operation data after a single sludge discharge cycle to complete a quantitative evaluation of sludge discharge effectiveness, and combines multi-cycle operation data to fit the cumulative settling pattern of sludge at the bottom of the tank. It adaptively updates the basic operation parameters for subsequent sludge discharge, forming a complete closed loop from media detection and process control to periodic review and self-correction. It eliminates the need for frequent on-site manual adjustment of equipment parameters and can autonomously adapt to sludge discharge strategies in response to the dynamic changes in influent sludge load over a long period of time, avoiding sludge accumulation and ineffective drainage. It achieves a synergistic optimization effect in adapting to the lag characteristics of sedimentation processes, accurately identifying sludge discharge media, ensuring thorough sludge discharge, and saving water and reducing consumption. Attached Figure Description

[0068] Figure 1 This is a structural diagram of a digital sludge removal system for a sedimentation tank;

[0069] Figure 2 This is a flowchart illustrating the division of the sludge section and the mixing transition section in this invention;

[0070] Figure 3 This is a flowchart of the micro-stroke self-test in this invention;

[0071] Figure 4 This is a flowchart of a digital sludge discharge control method for sedimentation tanks. Detailed Implementation

[0072] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solution of the present invention, rather than limitations thereof. In the absence of conflict, the embodiments of the present invention and the technical features in the embodiments can be combined with each other.

[0073] Example 1

[0074] refer to Figures 1 to 3 As shown in the figure, this embodiment introduces a digital sludge removal system for sedimentation tanks, including: an optical detection module, a control module, an electric valve, and a communication module;

[0075] The optical detection module is deployed at the sludge discharge outlet of the sedimentation tank to replace the original section of the sludge discharge pipeline. It is an integrated package consisting of a transparent observation tube, a light source, a light sensor, a flange, a manual bypass valve, and a light-shielding shell. The medium flowing through the sludge discharge pipeline is the object being measured. The detection light is applied to the object being measured and the light intensity signal after penetration is collected. The light intensity signal is then transmitted to the control module.

[0076] The transparent observation tube is made of high-transmittance PC material, which is corrosion-resistant, impact-resistant, and has good light transmittance to ensure that light can pass through smoothly and to ensure detection accuracy. During sludge discharge, the mixed medium of sludge and clean water flows through the transparent observation tube, forming the object to be measured in the detection optical path.

[0077] The light source uses infrared LEDs or visible LEDs to apply detection light to the object under test inside the transparent observation tube, and is deployed on one side of the transparent observation tube;

[0078] The light sensor is used to collect the light intensity signal transmitted through the object being measured. It is deployed on the opposite side of the transparent observation tube, opposite to the light source and coaxially arranged.

[0079] The flanges are made of stainless steel and are located at both ends of the transparent observation tube to seal the optical detection module to the sedimentation tank sludge discharge outlet pipeline and the downstream electric valve.

[0080] The manual bypass valve is connected in parallel with the electric valve to manually control the opening and closing of the sludge discharge pipeline in case of failure, such as electric valve failure, control module failure or power failure, to ensure the normal and continuous operation of sludge discharge in the sedimentation tank and improve the system's reliability and emergency response capabilities.

[0081] The light-shielding shell is deployed outside the optical detection module, completely covering the transparent observation tube and the detection optical path area where the internal optical path is located. It is used to block the interference of external ambient light and ensure that the light intensity signal collected by the light sensor comes only from the light after the light source penetrates the object being measured, which greatly improves the detection stability.

[0082] During the long-term operation of the sludge discharge pipeline, sludge easily adheres to the inner wall of the transparent observation tube, which blocks the detection light emitted by the light source, causing the light intensity signal collected by the light sensor to be distorted. The optical detection module has a built-in self-cleaning unit, which consists of a miniature high-pressure flushing nozzle deployed inside the transparent observation tube and connected to the external clean water pipeline. It is used to automatically flush the inner wall of the transparent observation tube periodically to ensure long-term stability of detection accuracy.

[0083] The optical detection module adopts a dual-optical-path redundancy design, including a main optical path and a reference optical path;

[0084] The main optical path consists of a transparent observation tube, a light source, and a light sensor, and is used to acquire the light intensity signal that penetrates the object being measured.

[0085] Because light sources naturally decay over long-term use, their luminous intensity decreases, which in turn affects the accuracy of the light intensity signal in the main optical path. The reference optical path is set in a sealed water cavity and contains a light source and light sensor of the same model as the main optical path. The transmittance of the medium in the sealed water cavity is constant. The light sensor in the reference optical path collects the light intensity signal that penetrates the sealed water cavity and uses it as a reference signal to calibrate the detection error caused by the decay of the light source in the main optical path, thereby improving the reliability and accuracy of the detection.

[0086] The control module receives the light intensity signal from the object being measured. Through transmittance analysis and time-series integration, it constructs a transmittance-time curve containing the relationship between transmittance and time. By performing trend analysis on the transmittance-time curve, it identifies the sludge discharge process stages and divides them into sludge segments and mixing transition segments for differentiated control in stages. For the sludge segment, to avoid incomplete sludge discharge, a valve opening signal is immediately generated to control the electric valve to remain open, ensuring that the concentrated sludge at the bottom of the tank is fully discharged and avoiding incomplete sludge discharge. For the mixing transition segment, the delayed valve closing time is dynamically calculated and a delayed valve closing signal is generated to dynamically match the optimal valve closing time, avoiding excessive sludge discharge while ensuring the thoroughness of sludge discharge. At the same time, after the current sludge discharge cycle is completed, the current sludge discharge effect is evaluated, and the sludge discharge cycle is adaptively adjusted based on the sludge discharge effect.

[0087] The control module includes a parsing unit, a perception and decision-making unit, and a self-testing unit.

[0088] The analysis unit is used to acquire the light intensity signal and the reference signal of the object under test. The reference signal is used to calibrate and compensate the light intensity signal to eliminate the detection error caused by the light source attenuation and ensure the accuracy of the transmittance value. The compensated light intensity signal is used to perform transmittance analysis and construct a transmittance time series curve based on the time series.

[0089] The perception and decision-making unit is used to perform trend analysis on the light transmittance time-series curve to identify the sludge discharge process stage by the change in light transmittance, and to divide the process into sludge segment and mixing transition segment for differentiated control in stages. For the sludge segment, a valve opening signal is generated to continuously open the electric valve. For the mixing transition segment, the valve closing time delay is calculated based on the rate of change of light transmittance as the minimum duration for continuous sludge discharge, avoiding premature valve closing that could lead to sludge backflow and re-accumulation at the bottom of the tank. The sludge is forcibly emptied by delay timing to eliminate instantaneous fluctuation interference. After the valve closing time delay is reached, it indicates a switch from the forced emptying mode to the final judgment waiting mode. The maximum timeout is calculated based on the critical light transmittance threshold to generate a delayed valve closing signal, including a valve closing signal and an abnormal warning signal.

[0090] The self-testing unit stores the operational data of each sludge discharge cycle. Before each sludge discharge cycle begins, it controls the electric valve to perform micro-stroke opening and closing actions, simultaneously detecting the transient response of light transmittance, and completing the micro-stroke self-test of valve operation status and pipeline on / off status. After each sludge discharge cycle is completed, it integrates the operational data of this sludge discharge cycle, including the light transmittance time sequence curve, total sludge discharge time, and stage division nodes. The effective sludge discharge time is used as an indicator to evaluate the sludge discharge effect. At the same time, based on the effective sludge discharge time of multiple consecutive sludge discharge cycles, it calculates the sludge accumulation rate at the bottom of the sedimentation tank and adaptively adjusts the next sludge discharge cycle.

[0091] The electric valve is deployed downstream of the optical detection module in the sludge discharge management system. It is used to receive various control signals from the control module and perform full-open, full-close, and micro-stroke opening and closing actions to realize the on-off control of the sludge discharge pipeline. The electric valve adopts a stainless steel electric butterfly valve, which has a short switching response time and a protection level suitable for the humid and dusty environment of the water treatment site. It can stably execute the action commands of the control module.

[0092] The communication module is used to establish a communication link between the optical detection module, the control module, and the electric valve. By reserving an RS485 interface or an Ethernet interface, it enables real-time data transmission and reception, ensuring information sharing and collaborative work among the modules, improving the stability and reliability of communication, and thus improving operating efficiency and response speed.

[0093] Furthermore, the steps for calibrating and compensating the light intensity signal using a reference signal include:

[0094] Preprocessing of light intensity signal and reference signal includes: smoothing continuous sampling points using moving average filtering algorithm to filter out high-frequency noise caused by electromagnetic interference and pipeline turbulence; removing outliers using the 3σ criterion; using the signal mean and standard deviation within a fixed sliding window as a benchmark; identifying sampling points that deviate from the mean by more than 3 times the standard deviation as abnormal jump points; and replacing the abnormal points with the signal mean within the window.

[0095] Since LED light sources experience natural light decay over time and ambient temperature fluctuations can cause luminous intensity drift, the transmitted light intensity of the reference optical path will change slowly and monotonically with the light source state. Therefore, the degree of light source attenuation can be quantified by the change in the light source state of the reference circuit, providing a benchmark for compensating for the detection error of the main optical path. The initial reference light intensity of the reference optical path during the initialization phase is retrieved, and the pre-processed reference reference signal is traversed according to the sampling time sequence. For each sampling time, the ratio of the reference light intensity at the corresponding time to the initial reference light intensity is calculated to obtain the relative attenuation coefficient at the corresponding sampling time.

[0096] The preprocessed light intensity signal of the object under test is traversed. For the light intensity value at each sampling time, the equivalent light intensity value converted to the initial light source intensity is obtained by calculating the ratio of the light intensity value to the relative attenuation coefficient. After all sampling points have completed the calculation, all equivalent light intensity values ​​are integrated in the original time order to obtain the calibration light intensity signal, thereby realizing the reverse compensation correction of the measured light intensity of the main optical path.

[0097] Furthermore, the steps for constructing the light transmission time sequence curve include:

[0098] Taking the sludge discharge cycle as the trigger node, after each self-cleaning unit completes the flushing of the inner wall of the transparent observation tube and the pipeline returns to a steady state of clear water, the sludge concentration in the transparent observation tube is 0, and the corresponding light transmittance is 100%, thus obtaining the initial light intensity of the sludge discharge in the medium of the main optical path.

[0099] Based on the sampling time, the equivalent light intensity in the calibration light intensity signal is traversed. The transmittance of the corresponding sampling point is obtained by the ratio of the equivalent light intensity to the initial light intensity of sludge discharge, so as to convert the physical light intensity signal into a standardized concentration characterization index.

[0100] The transmittance is arranged according to the sampling time and serialized to generate several discrete data pairs containing the correspondence between sampling time and transmittance.

[0101] Consistency checks are performed on all discrete data pairs based on the sampling interval. For missing sampling points caused by data transmission packet loss, linear interpolation is used to fill in the missing points to ensure the continuity of time series data.

[0102] With time as the horizontal axis and transmittance as the vertical axis, a smooth transmittance time-series curve is constructed through continuous fitting to present the transmittance change trajectory throughout the entire sludge discharge process.

[0103] Furthermore, the steps for dividing the sludge section and the mixing transition section include:

[0104] The sludge discharge start time is used as the global timing starting point for initial stable data acquisition to continuously obtain light transmittance. At this time, the default setting is the sludge segment.

[0105] Because residual clear water in the sludge discharge pipeline will flow through the detection section first at the moment of sludge discharge start, causing a false clear water signal, the transmittance will only drop to a low steady state after the concentrated sludge at the bottom of the pool has stabilized and entered the pipeline. The interference of residual liquid in the pipeline is avoided by using an initial bottom protection time to avoid misjudgment in the initial stage. The initialized sludge discharge initial time is called. When the stable collection time reaches the sludge discharge initial time, it indicates that the transmittance has entered a low steady state and enters the trend analysis stage. Among them, historical sludge discharge records are obtained, and the minimum effective sludge segment time in the historical sludge discharge cycle is used as the sludge discharge initial time.

[0106] Using the sampling points corresponding to the initial sludge discharge time as the effective sampling points for window analysis, the corresponding transmittance time-series curves are obtained and continuously updated as the number of sampling points increases. Based on the discrete sampling points in the curves, the transmittance difference between the current sampling point and the previous sampling point is used as the difference transmittance of the current sampling point, thus forming a differential noise sequence based on the initial sampling point.

[0107] A group of consecutive differential transmittance values ​​with completely consistent signs (all consecutive positive or all consecutive negative) is considered as a single in-phase change segment. By traversing the signs of the differential transmittance values ​​in the differential noise sequence, all in-phase change segments are segmented out. The number of sampling points for each segment is recorded, and the average number of all sampling points is calculated as the noise fluctuation point count. Twice the noise fluctuation point count is used as the lower bound of the window.

[0108] The sliding window introduces a trend recognition delay. If the delay exceeds the valve response time, the valve will not be able to close in time after the mud-water transition section is identified, resulting in a large amount of clean water being discharged and increasing the sludge dewatering load. Therefore, the rated response time of the electric valve switch is obtained, and half of the rated response time is taken as the maximum allowable recognition delay. The maximum allowable recognition delay is converted into the upper limit of the window by rounding up the sampling interval and the number of points. The maximum allowable recognition delay and the sampling interval are then rounded up.

[0109] Based on the transmittance time-series curve, the real-time standard deviation of transmittance is calculated. Simultaneously, after the sludge discharge pipeline completes self-cleaning and is filled with steady-state clean water medium, multiple sets of clean water transmittance are continuously collected through the optical detection module as clean water reference samples. The standard deviation of the clean water reference samples is calculated to obtain the clean water transmittance standard deviation. The ratio of the real-time standard deviation to the clean water transmittance standard deviation is used as the window point coefficient. The basic window point number is obtained by multiplying the window point coefficient by the lower boundary of the window. At the same time, boundary truncation is performed according to the upper and lower boundaries of the window. That is, when the basic window point number is less than the lower boundary of the window, the calculated basic window point number is replaced by the lower boundary of the window; when the basic window point number is greater than the upper boundary of the window, the calculated basic window point number is replaced by the upper boundary of the window. The sliding interval is one sampling point.

[0110] The sampling point corresponding to the initial duration of sludge discharge is taken as the end point of the first sliding window. If the total number of valid samples within the initial duration of sludge discharge is less than the number of points in the basic window, the missing data in front of the window is filled by repeating the first transmitted light sample value to ensure that the number of samples in the first window meets the standard and that there is no data loss causing slope distortion. The transmitted light time series curve starting from the timing start point is traversed, and several data subsets are divided according to the sliding window.

[0111] For each subset of data, with time as the independent variable and transmittance as the dependent variable, least squares linear fitting is used to obtain the transmittance change function of the corresponding sliding window, and the slope of the fitted transmittance change function is used as the instantaneous rate of change of transmittance.

[0112] If continuous If all instantaneous rate of change exceeds the threshold for switching, the system is determined to switch from the sludge section to the mixed transition section, and the transmittance and timestamp at the switching moment are recorded. Specifically, the instantaneous rate of change of all sludge sections within the initial sludge discharge time is extracted, and the arithmetic mean and standard deviation are calculated. The sum of the arithmetic mean and three times the standard deviation is used as the threshold for switching. Since brief spikes in transmittance are prone to occur within a single noise fluctuation cycle, the threshold must be met for two consecutive complete noise cycles to filter out false switching caused by single disturbances. This approach balances response speed and anti-interference capability; therefore, the following settings are used: This represents the number of sampling points at the lower bound of the window.

[0113] Because various real-world operating conditions during the sedimentation tank sludge discharge process can cause the sludge-water interface to recede and concentrated sludge to re-enter the detection pipeline, if only unidirectional switching is supported and no recede logic is set, the system will continuously perform delayed emptying according to the mixing transition section, ignoring the re-emerging concentrated sludge. This results in incomplete sludge discharge from the bottom of the tank, leading to incomplete sludge removal. For the mixing transition section, if continuous... If all instantaneous change rates are less than the fall-off switching threshold, it indicates that concentrated sludge clumps are re-entering the transparent observation tube, the sludge-water interface falls back, and the tube switches from the mixing transition section to the sludge section. The instantaneous change rate is continuously monitored. The fixed hysteresis coefficient built into the optical detection module is used as a correction coefficient to distinguish the bidirectional thresholds of the rising and falling switching stages. The coefficient is between 1.2 and 1.8. The ratio of the rising switching threshold to the hysteresis coefficient is used as the fall-off switching threshold.

[0114] Furthermore, the steps for generating the delayed valve-closing signal include:

[0115] When determining the continuity of the mixed transition section The instantaneous rate of change is used to calculate the average uplift rate of the mud-water interface at this time through arithmetic mean calculation;

[0116] The transmittance at the switching moment is retrieved, and the difference between the critical transmittance threshold and the transmittance at the switching moment is used as the effective transmittance difference. This represents the total increase in transmittance required for the medium to transition from a state of concentrated mud-water mixture to a state of complete clear water drainage, reflecting the current turbidity level and drainage difficulty. Specifically, after each self-cleaning of the transparent observation tube, the transmittance of the main optical path is acquired. The average transmittance is used to obtain the clear water baseline transmittance for the current sludge drainage cycle. Simultaneously, the transmittance at the end of each sludge drainage cycle is acquired, and the minimum value is used as the historical drainage lower limit. The weighted sum of the clear water baseline transmittance and the historical drainage lower limit is used as the critical transmittance threshold for the current sludge drainage cycle. Since... The current clean water reference transmittance is a real-time, accurate detection benchmark based on the current sludge discharge cycle, current optical path cleanliness, current device aging status, and current ambient temperature. It has the strongest timeliness and can accurately offset the system baseline drift caused by slight pipe fouling, long-term light source attenuation, and ambient temperature drift. It is the core parameter to ensure the accuracy of single-cycle detection, so it is given a dominant weight of 0.7. The historical discharge lower limit value is a long-term statistical law and is only used to constrain extreme instantaneous sampling errors and prevent threshold shift caused by abnormal clean water sampling in a single cycle. It is only used as an auxiliary correction item and is set to 0.3. Therefore, the weight of the clean water reference transmittance is greater than the weight of the historical discharge lower limit.

[0117] To compensate for the problems of short-term jumps in light transmission and instantaneous distortion of slope caused by irregular accumulation of sludge flocs and detachment of residual sludge from the pipe wall during sludge discharge, the instantaneous change rate dataset of sludge segments from nearly 20 effective historical sludge discharge cycles stored in the equipment was retrieved as historical statistical data. The standard deviation of the instantaneous change rate of sludge segments was calculated cycle by cycle. By averaging the standard deviations of all sludge discharge cycles, the baseline fluctuation value was obtained. The instantaneous change rate within the initial duration of sludge discharge in the current sludge discharge cycle was taken, and the steady-state standard deviation was calculated. The ratio of the steady-state standard deviation to the baseline fluctuation value was used as the fluctuation correction coefficient.

[0118] The delayed valve closing time is obtained by dividing the effective light transmittance difference by the average rise rate and then multiplying it by the fluctuation correction coefficient.

[0119] After generating the delayed valve closing time, a forced evacuation countdown is immediately started. The countdown decreases only if the entire countdown is in the mixing transition phase. If the countdown ends before switching back to the sludge phase, it is determined that the transparent observation tube has been re-entered with concentrated sludge clumps and the mud-water interface has fallen back, and the phase has returned to the sludge phase. At this time, the current forced evacuation countdown is immediately paused and cleared, and the calculated delay time is invalidated until the phase switches to the mixing transition phase, at which point the delayed valve closing time is recalculated.

[0120] Once the forced evacuation countdown reaches zero, a multi-branch decision is made by comparing the real-time transmittance with the critical transmittance threshold.

[0121] When continuous When the light transmittance is greater than the critical light transmittance threshold and the corresponding instantaneous change rate maintains a non-negative upward trend, it indicates that the mud-water mixture in the transparent observation tube has been completely emptied, the discharged medium is stable as clear water, there are no sludge flocs and no repeated fluctuations in concentration, the sludge discharge process has reached the termination condition, it is judged that the working condition meets the standard, and a valve closing signal is immediately generated to terminate the current sludge discharge cycle. At the same time, the sludge section duration, transition section duration and delay parameters of this sludge discharge are uploaded to the self-inspection unit for parameter optimization in the next sludge discharge cycle.

[0122] Starting with the countdown to zero for forced evacuation, a waiting period is set. If the operating condition is not deemed compliant after the maximum safe timeout period, it indicates abnormal issues such as partial pipe blockage, optical path contamination, abnormal sludge accumulation, or extreme fluctuations in influent water quality. The medium cannot be evacuated normally, constituting an abnormal sludge discharge condition, which is judged as a failure to meet the timeout standard. A constant warning signal is immediately generated, and the electric valve is forcibly closed to avoid meaningless continuous drainage waste. The abnormal sludge discharge data is marked as invalid samples and will not participate in subsequent adaptive iterations to prevent abnormal operating conditions from interfering with the accuracy of system parameters. The maximum safe timeout period is a fault fallback protection period used to avoid a dead loop condition where optical path failure, pipe blockage, or extreme sludge accumulation leads to permanent non-compliance. The data is retrieved from the sedimentation tank single-cycle... The maximum design effective volume of the sludge discharge pipeline and the rated flow rate of the sludge discharge pipeline are used to calculate the maximum process limit evacuation time, which is the longest time required for complete evacuation under the most severe sludge conditions. At the same time, the response margin time of the fully open and stable flow of the electric valve is obtained. The maximum safe overtime time is the product of the maximum process limit evacuation time and a safety margin coefficient of 1.2. The safety margin coefficient is a compensation coefficient superimposed on the theoretical process limit evacuation time. It is used to cover various unquantifiable deviations in field conditions, such as valve action response delay, pipeline medium flow disturbance, and non-ideal flow of severe sludge. A reasonable backup time is reserved on the basis of the theoretical maximum evacuation time to ensure that there is a sufficient evacuation window under abnormal sludge conditions without causing excessive amplification of the overtime threshold and resulting in ineffective drainage.

[0123] Furthermore, the steps for micro-travel self-check include:

[0124] If the valve is fully opened directly to start sludge discharge, if the valve core gets stuck or the valve stem transmission mechanism fails, the valve will not actually open, but the system will judge that sludge discharge is normal, resulting in a long period of ineffective standby. At the same time, if the front end of the pipeline is blocked, even if the valve is opened normally, the medium cannot flow through the optical detection section, and the subsequent light transmission time curve will not have obvious fluctuations, making it impossible to identify pipeline blockage. Before the formal sludge discharge and the issuance of the fully open valve command, the self-test unit issues a micro-stroke opening command to the electric valve, driving the electric valve to move from the fully closed position to the micro-stroke opening and maintain it for the set self-test duration. Then, a micro-stroke closing command is issued to return the valve to the fully closed and locked position. Among them, the total mechanical stroke of the electric valve is obtained, and 15% of the total mechanical stroke is used as the micro-stroke opening. In order to cover the single sampling cycle and ensure that multiple sets of continuous light transmission sampling points caused by valve opening and closing disturbances can be collected, avoiding the loss of fluctuation data due to insufficient sampling frequency, the self-test duration is 5 times the sampling interval.

[0125] Throughout the entire process of the electric valve performing micro-stroke movements, the transmittance of the main optical path is continuously acquired, and the self-test transmittance sequence generated by the electric valve movements is continuously recorded.

[0126] Perform range calculation on the self-test transmittance sequence, that is, obtain the maximum fluctuation amplitude by the difference between the maximum and minimum transmittance values;

[0127] Obtain the baseline fluctuation range and determine the on / off state; in the initial water commissioning stage of the optical detection module, under the standard working conditions of complete pipeline unobstructed and normal valve transmission, perform 10 consecutive micro-stroke self-checks, calculate the maximum fluctuation amplitude of each, take the arithmetic mean of 10 amplitudes, multiply by 0.6 as the baseline lower limit, and take the product of the arithmetic mean of 10 amplitudes and 1.8 as the baseline upper limit;

[0128] If the maximum fluctuation amplitude is within the baseline fluctuation range, it is determined that the electric valve transmission structure is normal and the pipeline is unobstructed, a self-inspection qualified signal is generated, and the subsequent formal sludge discharge process is allowed.

[0129] If the maximum fluctuation amplitude is not within the baseline fluctuation range, a self-test anomaly is determined, a self-test warning signal is generated, and the sludge discharge start command is locked and no longer issued until maintenance personnel report that the anomaly has been resolved, and the micro-stroke self-test continues. If the maximum fluctuation amplitude is less than the lower limit of the baseline fluctuation range, it indicates that the pipeline is completely blocked and there is no medium flow, or the valve is not actually opened. If the maximum fluctuation amplitude is greater than the upper limit of the baseline fluctuation range, it indicates that the electric valve cannot lock back normally and there is a valve core leakage fault.

[0130] Furthermore, the steps for adaptively adjusting the next sludge discharge cycle include:

[0131] After receiving the signals indicating that the sludge discharge valve is closed and the current sludge discharge cycle has ended, the system acquires data from the entire sludge discharge process, performs time alignment, and generates a sludge discharge dataset.

[0132] The sludge duration was extracted from the sludge discharge dataset as the effective sludge discharge duration to characterize the actual discharge period of high-concentration sludge at the bottom of the tank.

[0133] Obtain the standard range for sludge discharge and evaluate the sludge discharge effect in a single cycle. In the initial water commissioning phase of the optical detection module, the effective sludge discharge time was continuously collected for 15 rounds of no faults, stable influent water quality, and no abnormal sludge accumulation in the sedimentation tank. The arithmetic mean of the 15 effective sludge discharge times was calculated. 0.75 times the mean was used as the lower limit of the range to represent the minimum acceptable basic sludge discharge time, and 1.25 times the mean was used as the upper limit of the range to represent the longest reasonable sludge discharge time without excess clean water discharge.

[0134] If the effective sludge removal time is within the standard sludge removal range, it indicates that the current sludge removal is qualified and the sludge accumulated at the bottom of the pool is normally emptied.

[0135] If the effective sludge discharge time is less than the lower limit of the standard sludge discharge range, it indicates that the sludge discharge is too short, and it is determined that the sludge at the bottom of the pool has not been completely discharged, and there is a risk of sludge residue accumulation.

[0136] If the effective sludge discharge time is greater than the upper limit of the standard sludge discharge range, it indicates that the sludge discharge is too long, and it is determined that the amount of sludge accumulated at the bottom of the pond is too small, indicating that there is a problem of excessive drainage and waste of water resources.

[0137] The effective sludge discharge time for which sludge discharge is deemed qualified is obtained. The difference between the start times of two adjacent sludge discharge cycles is taken as the settling time in the sedimentation tank between the two cycles. The settling time is taken as the independent variable and the effective sludge discharge time is taken as the dependent variable. The least squares linear regression is used to fit the settling curve and the slope of the settling curve is taken as the sludge accumulation rate at the bottom of the sedimentation tank.

[0138] If the sludge accumulation rate is greater than the baseline sludge accumulation rate, it indicates that the sludge settling and accumulation speed per unit settling time is higher than the design benchmark, the influent suspended solids load is too high, the sludge accumulation rate at the bottom of the tank is fast, and it is very easy to accumulate excessively. Therefore, the initial sludge discharge time should be shortened, the settling time in the sedimentation tank should be reduced, the sludge discharge task should be initiated in advance to avoid excessive thickening and compression of the sludge layer, the interval between initiating the next round of sludge discharge should be extended, and the forced basic sludge discharge time of the sludge section should be lengthened to ensure that more bottom sludge generated by high-speed settling is completely discharged. The adjustment ratio is the ratio of the sludge accumulation rate to the baseline sludge accumulation rate, that is, proportional scaling. Among them, in the initial water supply and commissioning stage of the optical detection module, 15 sets of stable qualified samples are obtained, and the initial slope is obtained by performing least squares regression and solidified as the baseline sludge accumulation rate as a reference threshold for judging the settling speed.

[0139] If the sludge accumulation rate is not greater than the baseline sludge accumulation rate, it indicates that the sludge settling and accumulation rate is low, the sludge content in the influent is low, and the sludge accumulation at the bottom of the tank is slow. Therefore, it is necessary to extend the initial sludge discharge time, lengthen the settling period, reduce unnecessary frequent sludge discharge, shorten the interval between starting the next round of sludge discharge, shorten the basic forced sludge discharge period, and reduce ineffective discharge of clean water.

[0140] Example 2

[0141] Please see Figure 4 Another embodiment of the present invention provides a digital sludge discharge control method for sedimentation tanks, comprising the following steps:

[0142] Initialize operating parameters, including initial sludge discharge time, critical light transmittance threshold, and sludge discharge interval. Once the sludge discharge cycle is reached or a sludge discharge command is received, perform micro-stroke self-check by controlling the electric valve.

[0143] A valve opening signal is generated only when the micro-stroke self-test is qualified, and the electric valve is fully opened to carry out the sludge discharge operation;

[0144] For the sludge removal operation, a light source continuously emits detection light into the object under test inside the transparent observation tube, and the light intensity signal of the object under test is collected in real time based on the light sensor. Through calibration and compensation of the reference signal and transmittance analysis, a transmittance time series curve is constructed.

[0145] By analyzing the trend of the light transmittance time curve, the sludge section and the mixing transition section are divided.

[0146] For the sludge section, a valve opening signal is generated; for the mixing transition section, a forced evacuation countdown is performed by delaying the valve closing time, and a maximum timeout is performed by combining the critical light transmittance threshold to generate a delayed valve closing signal.

[0147] After the sludge discharge is completed, the sludge discharge effect is evaluated, and the next sludge discharge cycle is adaptively adjusted based on the sludge accumulation rate of multiple consecutive sludge discharge cycles.

[0148] Working principle and effects:

[0149] By relying on optical detection to collect the light intensity signal of the medium in the sludge discharge pipeline in real time, and obtaining the continuous light transmission time sequence curve through analysis, the initial steady-state acquisition is completed based on the sludge discharge start time, avoiding the interference of initial detection by residual clear water in the pipeline. The instantaneous change rate of light transmittance is fitted by an adaptive sliding window, and the sludge section and the mixing transition section are accurately divided by dual threshold hysteresis judgment, realizing the phased differentiated control of the sludge discharge process. At the same time, the pre-process micro-stroke self-check ensures the normal operation of the equipment, and the post-process multi-cycle data statistics fit the sludge accumulation rate, adaptively iteratively updating the core parameters of subsequent sludge discharge. It abandons the lag defect of traditional reliance on influent index control, fits the process characteristics of sludge settling time lag, and can distinguish in real time whether the medium discharged from the pipeline is concentrated sludge or sludge-water mixture, accurately judge the effective state of sludge discharge, effectively improve the solid content of sludge discharge, and reduce the load of subsequent sludge dewatering. Meanwhile, by linking dynamic delayed emptying with threshold final judgment control, it avoids misjudgment valve closure or excessive drainage caused by instantaneous disturbances. Combined with a periodic adaptive correction mechanism, it continuously adapts to the dynamic changes in water quality and sludge quantity, realizing the intelligent and stable operation of sedimentation tank with precise, thorough, and water-saving sludge discharge.

[0150] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A digital sludge removal system for sedimentation tanks, characterized in that, include: Optical inspection module, control module, and electric valve; The optical detection module is used to apply detection light to the object under test and collect light intensity signals, while also performing self-cleaning. The control module is used to receive the light intensity signal, construct a light transmittance time sequence curve by analyzing the light transmittance and integrating the time sequence, divide the light transmittance time sequence curve into sludge segment and mixing transition segment by performing trend analysis, and perform differentiated control in stages. At the same time, after the current sludge discharge cycle is completed, the current sludge discharge effect is evaluated, and the sludge discharge cycle is adaptively adjusted based on the sludge discharge effect. The electric valve is used to receive control signals from the control module and to control the opening and closing of the sludge discharge pipeline.

2. The digital sludge removal system for sedimentation tanks according to claim 1, characterized in that: The optical detection module is configured with dual optical paths, including a main optical path and a reference optical path; The main optical path uses a mixture of sludge and clean water as the object under test to acquire the light intensity signal that penetrates the object under test. The reference optical path uses a medium with constant transmittance as a reference object to obtain a reference signal that penetrates the reference object.

3. The digital sludge removal system for sedimentation tanks according to claim 2, characterized in that: The control module includes a parsing unit, a perception and decision-making unit, and a self-testing unit; The analysis unit uses the reference signal to calibrate and compensate the light intensity signal, and performs transmittance analysis on the compensated light intensity signal, and constructs a transmittance time series curve by combining the time series. The sensing and decision-making unit is used to perform trend analysis on the light transmission time curve, divide it into sludge segment and mixing transition segment. For the sludge segment, a valve opening signal is generated. For the mixing transition segment, forced evacuation is performed according to the calculated delayed valve closing time. After the delayed valve closing time is reached, the maximum timeout is calculated according to the critical light transmission threshold, and a delayed valve closing signal is generated. The self-testing unit is used to store the operation process data of each sludge discharge cycle. Before each sludge discharge cycle starts, it performs a micro-stroke self-test by controlling the electric valve. After the sludge discharge cycle is completed, it adaptively adjusts the next sludge discharge cycle by the effective sludge discharge time.

4. The digital sludge removal system for sedimentation tanks according to claim 3, characterized in that, The calibration and compensation of the light intensity signal using the reference signal includes: The light intensity signal and the reference signal are preprocessed. Retrieve the initial reference light intensity of the reference optical path described in the initialization phase; For the preprocessed reference signal, the reference light intensity at each sampling time is retrieved, and the relative attenuation coefficient at each sampling time is obtained by the ratio of the reference light intensity to the initial reference light intensity. For the preprocessed light intensity signal, retrieve the light intensity value at each sampling time, and obtain the equivalent light intensity value by the ratio of the light intensity value to the corresponding relative attenuation coefficient; All equivalent light intensity values ​​are integrated according to the sampling time sequence to obtain the calibration light intensity signal.

5. The digital sludge removal system for sedimentation tanks according to claim 4, characterized in that, Constructing the light transmission time sequence curve includes: Using the sludge discharge cycle as the trigger node, the initial light intensity of the medium in the main optical path is obtained after each self-cleaning is completed. Based on the sampling time, the equivalent light intensity in the calibration light intensity signal is traversed, and the transmittance of the corresponding sampling point is obtained by the ratio of the equivalent light intensity to the initial light intensity of sludge discharge. The transmittance is arranged according to the sampling time and serialized to generate discrete data pairs containing the correspondence between sampling time and transmittance. Consistency checks are performed on all discrete data pairs based on the sampling interval, and linear interpolation is used to fill in missing sampling points caused by data transmission packet loss. A smooth light transmission time curve is constructed by using time as the horizontal axis and light transmittance as the vertical axis through continuous fitting.

6. A digital sludge removal system for sedimentation tanks according to claim 5, characterized in that, The sludge section and the mixing transition section are divided into: The transmittance is continuously acquired starting from the sludge discharge start time, and at this time it is assumed to be the sludge section; Once the timing reaches the initial duration of sludge discharge, a differential noise sequence is constructed by performing a first-order difference operation on the light transmission time sequence curve. Taking the continuous consistent sign of the difference transmittance as in-phase change, the differential noise sequence is traversed to segment multiple in-phase change segments. The lower bound of the window is set by the mean and multiple calculation of the number of sampling points. Set the upper limit of the window based on the rated response time of the electric valve switch; Calculate the real-time standard deviation of light transmittance, combine it with the standard deviation of light transmittance of clear water and the lower limit of the window, set the number of basic window points, and perform boundary truncation; Based on the light transmission time series curve, multiple data subsets were divided, and the instantaneous rate of change was calculated using least squares linear fitting. If continuous If all instantaneous change rates are greater than the rising switching threshold, it is determined that the sludge section is being switched to the mixed transition section. For the mixed transition section, if continuous If all instantaneous change rates are less than the fallback switching threshold, it is determined that the system will fall back to sludge.

7. A digital sludge removal system for sedimentation tanks according to claim 6, characterized in that, The generation of the delayed valve closing signal includes: When determining the continuity of the mixed transition section Calculate the average rate of rise based on the instantaneous rate of change; The transmittance at the switching moment is retrieved, and the difference is calculated by combining it with the critical transmittance threshold to obtain the effective transmittance difference; Based on the instantaneous change rate of the sludge section, historical statistical data is obtained, and the benchmark fluctuation value is calculated using the standard of a single sludge discharge cycle. Based on the standard deviation of the instantaneous change rate within the initial sludge discharge time and the benchmark fluctuation value, the fluctuation correction coefficient is calculated. Combined with the effective light transmittance difference and the average lifting rate, the delayed valve closing time is calculated, and a forced evacuation countdown is performed. After the forced empty countdown reaches zero, perform a multi-branch decision. When continuous When the light transmittance is greater than the critical light transmittance threshold and the instantaneous rate of change maintains a non-negative upward trend, the operating condition is deemed to be in compliance, and a valve closing signal is generated. Starting with the countdown to zero for forced evacuation, a waiting period is set. If the operating condition is not deemed to meet the standard after the waiting period reaches the maximum safe overtime period, a regular early warning signal is generated.

8. A digital sludge removal system for sedimentation tanks according to claim 7, characterized in that, The steps of the micro-travel self-check include: Before the formal sludge discharge, a micro-stroke opening command is issued to the electric valve, driving the electric valve to move from the fully closed position to the micro-stroke opening degree and maintain the set self-check time, and then a micro-stroke closing command is issued. Throughout the entire process of the electric valve performing micro-stroke actions, the transmittance of the main optical path is continuously acquired to construct a self-test transmittance sequence; The maximum fluctuation amplitude is obtained by performing range calculation on the self-test transmittance sequence; Obtain the baseline fluctuation range and determine the on / off status; If the maximum fluctuation amplitude is within the benchmark fluctuation range, a self-inspection qualified signal is generated, triggering the sludge discharge process; If the maximum fluctuation amplitude is not within the benchmark fluctuation range, the self-check is determined to be abnormal, and a self-check early warning signal is generated.

9. A digital sludge removal system for sedimentation tanks according to claim 8, characterized in that, Adaptive adjustment of the next sludge discharge cycle includes: Acquire data from the entire sludge removal process, align it with the time frame, and generate a sludge removal dataset. Extract the sludge duration from the sludge discharge dataset as the effective sludge discharge duration; Obtain the standard range for sludge discharge and conduct a single-cycle sludge discharge effect evaluation to determine whether the current round of sludge discharge is qualified. The effective sludge discharge time for which sludge discharge is deemed qualified is obtained. The difference between the start times of two adjacent sludge discharge cycles is used as the settling time. The settling time is used as the independent variable and the effective sludge discharge time is used as the dependent variable. The sludge accumulation rate is obtained by fitting the data using least squares linear regression. If the sludge accumulation rate is greater than the baseline sludge accumulation rate, then shorten the initial sludge discharge time and extend the interval for starting the next round of sludge discharge; otherwise, extend the initial sludge discharge time and shorten the interval for starting the next round of sludge discharge.

10. A digital sludge discharge control method for a sedimentation tank, used to implement a digital sludge discharge system for a sedimentation tank as described in any one of claims 1-9, characterized in that, include: Initialize operating parameters. Once the sludge discharge cycle is reached or a sludge discharge command is received, perform a micro-stroke self-check by controlling the electric valve. Sludge discharge is only allowed when the micro-stroke self-check is qualified. The light source continuously emits detection light into the object under test inside the transparent observation tube, and the light intensity signal of the object under test is collected in real time based on the light sensor. Through calibration and compensation of the reference signal and transmittance analysis, a transmittance time series curve is constructed. By analyzing the trend of the light transmittance time curve, the sludge section and the mixing transition section are divided. For the sludge section, a valve opening signal is generated; for the mixing transition section, a forced evacuation countdown is performed by delaying the valve closing time, and a maximum timeout is performed by combining the critical light transmittance threshold to generate a delayed valve closing signal. After the sludge discharge is completed, the sludge discharge effect is evaluated, and the next sludge discharge cycle is adaptively adjusted based on the sludge accumulation rate of multiple consecutive sludge discharge cycles.

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