An intelligent dimming system for an LED warning screen

Abstract

The present invention relates to the field of intelligent dimming technology, and specifically discloses an intelligent dimming system for an LED warning screen, which includes an LED warning screen body and an intelligent dimming controller; wherein, the intelligent dimming controller includes a light sensor, a voltage regulation module, a microprocessor, a light intensity fluctuation analysis module, and an adjustment optimization module; the light intensity fluctuation analysis module: analyzes the light intensity change situation of the surrounding environment based on the real-time obtained light intensity, and generates a frequent light intensity change signal based on the analysis result; the adjustment optimization module: analyzes the stability of the light intensity change based on the frequent light intensity change signal, and thus optimizes the adjustment frequency and voltage adjustment value of the voltage regulation module for regulating the working voltage of the LED lamp beads based on the analysis result; the present invention realizes the dynamic adjustment of the brightness of the LED warning screen by intelligently sensing and analyzing the environmental light intensity change, which not only ensures the warning effect, but also effectively saves energy and improves the overall performance of the system.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent dimming, and particularly relates to an intelligent dimming system for an LED warning screen. Background Art

[0002] An LED screen is a new type of imaging electronic device made by arranging light-emitting diodes in sequence. Due to its high brightness, wide viewing angle, long lifespan and other characteristics, it is being widely used in products such as outdoor advertising screens.

[0003] Chinese Patent Invention Publication No. CN115457905A discloses an adaptive dimming compensation method, device, system and electronic device for an LED display screen, belonging to the field of LED display screens. The method is applied to an adaptive dimming compensation system of an LED display screen and is executed by an electronic device. The method includes: obtaining image information of the display screen based on an industrial camera at preset time intervals; obtaining the ambient light brightness value at preset time intervals; obtaining the actual brightness value of each area of the display screen based on the image information; inputting the ambient light brightness data into a neural network model to obtain the preset brightness value of the display screen corresponding to the ambient light brightness value; comparing the actual brightness value of each area with the preset brightness value, and adjusting the brightness of the area according to the comparison result so that the area reaches the preset brightness value.

[0004] However, traditional LED warning screens often lack intelligence and flexibility in brightness adjustment and cannot be dynamically adjusted according to changes in ambient light intensity. This may not only lead to insufficient warning effects but also cause unnecessary energy waste. Therefore, it is particularly important to develop an LED warning screen system that can intelligently sense changes in ambient light and automatically adjust brightness. Summary of the Invention

[0005] The purpose of the present invention is to provide an intelligent dimming system for an LED warning screen to solve the above technical problems in the background.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] The present invention provides an intelligent dimming system for an LED warning screen, including an LED warning screen body and an intelligent dimming controller;

[0008] Among them, the intelligent dimming controller includes a light sensor, a voltage regulation module, a microprocessor, a light fluctuation analysis module and an adjustment optimization module;

[0009] The light fluctuation analysis module: analyzes the light change situation of the surrounding environment based on the real-time obtained light intensity, and generates a frequent light change signal based on the analysis result;

[0010] The adjustment and optimization module: Based on the frequent light change signal, analyze the stability of the light change, and then optimize the adjustment frequency and voltage adjustment value of the voltage adjustment module for adjusting the working voltage of the LED lamp beads based on the analysis result. The specific process is as follows:

[0011] Based on the frequent light change signal, preset a sliding detection period;

[0012] Based on the sliding detection period within the historical target period, obtain the light sliding period characterization value of the sliding detection period;

[0013] Then, based on the light sliding period characterization value of the sliding detection period, calculate the sliding change coefficient of the historical target period;

[0014] Preset a sliding change coefficient threshold, and compare and analyze the sliding change coefficient with the sliding change coefficient threshold;

[0015] If the sliding change coefficient is less than or equal to the sliding change coefficient threshold, generate a change stable signal;

[0016] If the sliding change coefficient is greater than the sliding change coefficient threshold, generate a change unstable signal;

[0017] Based on the change stable signal and the change unstable signal respectively, optimize the adjustment frequency and voltage adjustment value of the voltage adjustment module for adjusting the working voltage of the LED lamp beads.

[0018] As a further solution of the present invention: The light sensor is used to detect the light intensity of the surrounding environment in real time, generate a light intensity signal based on the light intensity, and send the detected light intensity signal to the microprocessor.

[0019] As a further solution of the present invention: The microprocessor adjusts the working voltage of the LED lamp beads through the voltage adjustment module according to the received light intensity signal, thereby changing the brightness of the LED lamp beads.

[0020] As a further solution of the present invention: The process of analyzing the light change situation of the surrounding environment based on the real-time obtained light intensity and generating a frequent light change signal based on the analysis result is as follows:

[0021] Based on the two-dimensional coordinate system with time as the X-axis and light intensity as the Y-axis, plot the real-time change curve of the light intensity;

[0022] Preset a historical target period, and the historical target period includes multiple light change detection periods;

[0023] Based on the real-time change curve of the light intensity, obtain the light period characterization value within each light change detection period, so as to obtain a light period characterization value sequence: , where N represents the length of the sequence of light cycle characterization values;

[0024] Based on the sequence of light cycle characterization values, obtain the light change coefficient;

[0025] Based on the light change coefficient, analyze the light change situation of the surrounding environment, and generate a frequent light change signal based on the analysis result.

[0026] As a further solution of the present invention: the process of obtaining the light cycle characterization value is as follows:

[0027] Extract the area enclosed between the real-time light intensity change curve and the X-axis within the light change detection period, and mark it as the light cycle characterization value.

[0028] As a further solution of the present invention: the process of obtaining the light change coefficient based on the sequence of light cycle characterization values is as follows:

[0029] Perform normalization processing on the sequence of light cycle characterization values;

[0030] Use the wavelet basis function to perform wavelet decomposition on the normalized sequence of light cycle characterization values to obtain the detail coefficients. The specific process is as follows:

[0031] Preset the normalized sequence of light cycle characterization values as , where the value of n is 1, 2,..., N;

[0032] Through the formula: , calculate to obtain the detail coefficient ;

[0033] where L is the length of the filter, k is the summation index, and the value range is from 0 to L - 1, is the coefficient of the high-pass filter in the wavelet decomposition process;

[0034] Through the formula: , calculate to obtain the light change coefficient E.

[0035] As a further solution of the present invention: the process of analyzing the light change situation of the surrounding environment based on the light change coefficient and generating a frequent light change signal based on the analysis result is as follows:

[0036] Preset the light change coefficient threshold, and compare and analyze the light change coefficient with the light change coefficient threshold;

[0037] If the light change coefficient is greater than the light change coefficient threshold, generate a frequent light change signal.

[0038] As a further solution of the present invention: the process of calculating the sliding change coefficient of the historical target period based on the light sliding period characterization value of the sliding detection period is as follows:

[0039] Based on a two-dimensional coordinate system with time as the X-axis and the characterization value of the illumination sliding period as the Y-axis, a curve showing the change of the characterization value of the illumination sliding period is plotted.

[0040] Extract the length of the curve showing the change of the characterization value of the illumination sliding period, calculate the difference from the length of the characterization of the historical target period duration, take the absolute value to obtain the length of the sliding change characterization, and then calculate the ratio of the length of the sliding change characterization to the length of the characterization of the historical target period duration to obtain the sliding change coefficient.

[0041] Among them, the length of the characterization of the historical target period duration is expressed as the length of the historical target period duration in a two-dimensional coordinate system with time as the X-axis and the characterization value of the illumination sliding period as the Y-axis.

[0042] As a further solution of the present invention: The process of optimizing the adjustment frequency and voltage adjustment value of the voltage adjustment module for adjusting the working voltage of the LED lamp beads based on the stable change signal is as follows:

[0043] Based on the stable change signal, extract the average value of the real-time ambient illumination intensity at each time point within the target period to obtain the illumination intensity mean value, thereby generate an illumination intensity signal based on the illumination intensity mean value, and send the illumination intensity signal to the microprocessor. The microprocessor adjusts the working voltage of the LED lamp beads through the voltage adjustment module according to the received illumination intensity signal, thereby changing the brightness of the LED lamp beads.

[0044] As a further solution of the present invention: The process of optimizing the adjustment frequency and voltage adjustment value of the voltage adjustment module for adjusting the working voltage of the LED lamp beads based on the unstable change signal is as follows:

[0045] Based on the unstable change signal, extract the real-time ambient illumination intensity at each time point within the target period, and sort the real-time ambient illumination intensity in ascending order according to the magnitude of the real-time ambient illumination intensity value to obtain the real-time ambient illumination intensity sequence, and extract the first quartile value and the third quartile value of the real-time ambient illumination intensity sequence, thereby obtaining the illumination intensity fluctuation range.

[0046] Among them, the upper limit of the illumination intensity fluctuation range is the third quartile value of the real-time ambient illumination intensity sequence, and the lower limit of the illumination intensity fluctuation range is the first quartile value of the real-time ambient illumination intensity sequence.

[0047] Based on the illumination intensity fluctuation range, the brightness of the LED lamp beads is adjusted in real time. When the ambient illumination intensity exceeds the illumination intensity fluctuation range, the working voltage of the LED lamp beads is not adjusted.

[0048] The beneficial effects of the present invention:

[0049] The present invention establishes a two-dimensional coordinate system of time - light intensity, plots the real-time change curve of light intensity, and sets a historical target period and multiple light change detection cycles; the system calculates the light characterization value within each cycle, calculates the light change coefficient, compares it with a preset threshold to determine the frequency of light change; based on the analysis result of light change, the system optimizes the voltage regulation strategy; if the light change is frequent but stable, the system calculates the average value of light intensity within the target period as the benchmark for adjusting brightness, reduces unnecessary brightness adjustments, and lowers energy consumption; if the light change is unstable, the system determines a light intensity fluctuation range and adjusts the LED brightness only within this range according to the real-time light intensity; when the ambient light exceeds this range, the system maintains the current brightness unchanged to avoid over-regulation; the present invention realizes the dynamic adjustment of the brightness of the LED warning screen through intelligent perception and analysis of ambient light changes, which not only ensures the warning effect but also effectively saves energy and improves the overall performance of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The present invention will be further described below in conjunction with the accompanying drawings.

[0051] Figure 1 is the system block diagram of Embodiment 1 of the present invention;

[0052] Figure 2 is the flow block diagram of Embodiment 2 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0053] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0054] Embodiment 1:

[0055] Please refer to Figure 1 and Figure 2 As shown, an intelligent dimming system for an LED warning screen according to an embodiment of the present invention includes an LED warning screen body and an intelligent dimming controller;

[0056] Among them, the LED warning screen body includes a plurality of LED lamp beads. The lamp beads are lens lamps with a convex lens (epoxy resin droplet reinforcement) on the surface, which has a light-gathering effect, making the light emit farther and brighter;

[0057] The intelligent dimming controller is connected to the LED warning screen body and is used to control the brightness of the LED lamp beads;

[0058] Among them, the intelligent dimming controller includes a light sensor, a voltage regulation module, and a microprocessor;

[0059] The light sensor is used to detect the light intensity of the surrounding environment in real time, generate a light intensity signal based on the light intensity, and send the detected light intensity signal to the microprocessor;

[0060] The microprocessor adjusts the working voltage of the LED lamp beads through the voltage regulation module according to the received light intensity signal, thereby changing the brightness of the LED lamp beads, that is, adjusting the brightness of the LED lamp beads in real time;

[0061] Voltage regulation module: According to the instructions of the microprocessor, accurately adjust the working voltage applied to the LED lamp beads;

[0062] It should be noted that when the light sensor detects that the light intensity of the surrounding environment is strong, the microprocessor will control the voltage regulation module to reduce the working voltage of the LED lamp beads, so as to reduce the brightness of the LED lamp beads and reduce energy consumption; on the contrary, when the light sensor detects that the light intensity of the surrounding environment is weak, the microprocessor will control the voltage regulation module to increase the working voltage of the LED lamp beads, so as to increase the brightness of the LED lamp beads to ensure the warning effect;

[0063] The technical solution of the embodiment of the present invention is mainly: The system is mainly composed of an LED warning screen body and an intelligent dimming controller; the LED warning screen body uses lens lamp beads, which have a light condensing effect, making the light spread farther and brighter; the intelligent dimming controller includes a light sensor, a voltage regulation module and a microprocessor; the light sensor detects the ambient light intensity in real time and sends the signal to the microprocessor; the microprocessor adjusts the working voltage of the LED lamp beads flexibly through the voltage regulation module according to the received signal, so as to accurately control its brightness.

[0064] Embodiment 2:

[0065] On the basis of Embodiment 1, please refer to Figure 1 、 Figure 2 As shown, in the intelligent dimming system of an LED warning screen described in the embodiment of the present invention, the intelligent dimming controller further includes:

[0066] Light fluctuation analysis module: Based on the real-time obtained light intensity, analyze the light change situation of the surrounding environment, and generate a light change frequent signal based on the analysis result;

[0067] In some implementation schemes, a two-dimensional coordinate system with time as the X-axis and light intensity as the Y-axis is established, and a real-time change curve of the light intensity is drawn;

[0068] A preset historical target period is set, and the historical target period includes multiple light change detection cycles;

[0069] Among them, the light change detection period can be 5 seconds, 10 seconds, or 30 seconds;

[0070] Based on the real-time light intensity change curve, calculate the light cycle characterization value within each light change detection period, thereby obtaining a sequence of light cycle characterization values: , where N represents the length of the sequence of light cycle characterization values, starting from 1 and counting up to N, used to identify the position of each light cycle characterization value in the sequence;

[0071] Exemplarily, the process of obtaining the light cycle characterization value is as follows:

[0072] Extract the area enclosed by the real-time light intensity change curve and the X-axis within the light change detection period, and mark it as the light cycle characterization value;

[0073] In order to eliminate the dimensional difference between different light intensity data, normalize the sequence of light cycle characterization values. For example, use the min-max normalization method to map the data to the interval [0, 1];

[0074] Use wavelet basis functions to perform wavelet decomposition on the normalized sequence of light cycle characterization values to obtain detail coefficients;

[0075] It should be noted that the wavelet basis functions include but are not limited to: Haar wavelet, Daubechies wavelet (db series), Symlets wavelet;

[0076] It should be noted that wavelet decomposition decomposes the signal at different scales. Each layer of decomposition will obtain a set of approximation coefficients (representing the low-frequency part of the signal, reflecting the overall trend of the signal) and a set of detail coefficients (representing the high-frequency part of the signal, reflecting the local changes of the signal). Wavelet decomposition is based on the discrete wavelet transform (DWT), and its core is to perform convolution and downsampling operations on the signal through a pair of filters (low-pass filter h and high-pass filter g);

[0077] Exemplarily, the calculation process of the detail coefficients is as follows:

[0078] Preset the normalized sequence of light cycle characterization values as , where n takes values of 1, 2,..., N;

[0079] Through the formula: , calculate and obtain the detail coefficients ;

[0080] Among them, L is the length of the filter, k is the summation index, and the value range is from 0 to L - 1, is the coefficient of the high-pass filter in the wavelet decomposition process;

[0081] Through the formula: , the light change coefficient E is calculated and obtained;

[0082] A preset light change coefficient threshold is set, and the light change coefficient is compared and analyzed with the light change coefficient threshold. By comparing and analyzing the light change coefficient with the light change coefficient threshold, it is possible to intuitively determine whether the light change in the surrounding environment is frequent during the historical target period;

[0083] It should be explained that the setting of the light change coefficient threshold needs to be considered based on the level of wavelet decomposition, that is, the numerical values of the light change coefficient thresholds corresponding to each layer of decomposition may be different;

[0084] If the light change coefficient is greater than the light change coefficient threshold, it indicates that the light change in the surrounding environment is relatively frequent during the historical target period, that is, a light change frequent signal is generated;

[0085] If the light change coefficient is less than or equal to the light change coefficient threshold, it indicates that the light change in the surrounding environment is relatively stable during the historical target period;

[0086] Adjustment and optimization module: Based on the light change frequent signal, analyze the stability of the light change, and thus optimize the adjustment frequency and voltage adjustment value of the voltage adjustment module for adjusting the working voltage of the LED lamp beads based on the analysis results;

[0087] In some implementation schemes, a sliding detection period is preset based on the light change frequent signal;

[0088] Among them, the duration of the sliding detection period is the same as the duration of the light change detection period;

[0089] Based on the sliding detection period within the historical target period, the light sliding period characterization value of the sliding detection period is obtained;

[0090] It should be explained that the method for obtaining the light sliding period characterization value is the same as the method for obtaining the light period characterization value, and will not be elaborated here;

[0091] It should be further explained that the sliding detection period is updated in real time based on time, that is, the light sliding period characterization value is also a real-time value;

[0092] Based on the two-dimensional coordinate system with time as the X-axis and the light sliding period characterization value as the Y-axis, a light sliding period characterization value change curve is plotted;

[0093] Extract the length of the light sliding period characterization value change curve, calculate the difference from the length characterization of the historical target period duration, and take the absolute value to obtain the sliding change characterization length. Then calculate the ratio of the sliding change characterization length to the length characterization of the historical target period duration to obtain the sliding change coefficient;

[0094] Among them, the length of the historical target time period is represented as the length of the historical target time period in a two-dimensional coordinate system established with time as the X-axis and the light intensity sliding period characterization value as the Y-axis;

[0095] A preset sliding change coefficient threshold is used to compare and analyze the sliding change coefficient with the sliding change coefficient threshold, so as to judge whether the change state of the ambient light intensity in the historical target time period is stable or unstable;

[0096] If the sliding change coefficient is less than or equal to the sliding change coefficient threshold, it means that the change of the ambient light intensity in the historical target time period is relatively stable, that is, a change stable signal is generated;

[0097] If the sliding change coefficient is greater than the sliding change coefficient threshold, it means that the change of the ambient light intensity in the historical target time period is unstable, that is, a change unstable signal is generated;

[0098] Based on the change stable signal, the average value of the real-time ambient light intensity at each time point in the target time period is extracted to obtain the light intensity average value. Then, a light intensity signal is generated based on the light intensity average value and sent to the microprocessor. The microprocessor adjusts the working voltage of the LED lamp beads through the voltage regulation module according to the received light intensity signal, thereby changing the brightness of the LED lamp beads;

[0099] It should be explained that based on the change stable signal, it means that the change of the ambient light intensity in the historical target time period is frequent but relatively stable. That is, the light intensity average value is obtained and used as a stable reference value for adjusting the brightness of the LED lamp beads. That is, when the ambient light intensity fluctuates frequently and stably, the brightness adjustment of the LED lamp beads is based on the light intensity average value as a reference and maintains that brightness, thereby reducing the frequency of brightness adjustment of the LED lamp beads;

[0100] Based on the change unstable signal, the real-time ambient light intensity at each time point in the target time period is extracted, and the real-time ambient light intensity is sorted in ascending order according to the magnitude of the real-time ambient light intensity value to obtain a real-time ambient light intensity sequence. The first quartile value and the third quartile value of the real-time ambient light intensity sequence are extracted, thereby obtaining a light intensity fluctuation range;

[0101] Among them, the upper limit of the light intensity fluctuation range is the third quartile value of the real-time ambient light intensity sequence, and the lower limit of the light intensity fluctuation range is the first quartile value of the real-time ambient light intensity sequence;

[0102] The brightness of the LED lamp beads is adjusted in real time based on the light intensity fluctuation range. When the ambient light intensity exceeds the light intensity fluctuation range, the working voltage of the LED lamp beads is not adjusted;

[0103] Exemplarily, when the ambient light intensity exceeds the lower limit of the light intensity fluctuation range, that is, when the ambient light intensity is less than the first quartile value of the real-time ambient light intensity sequence, the brightness of the LED lamp beads is stabilized and adjusted according to the brightness of the LED lamp beads corresponding to the first quartile value of the real-time ambient light intensity sequence;

[0104] The technical solution of the embodiment of the present invention is mainly as follows: by establishing a two-dimensional coordinate system of time-light intensity, drawing a real-time change curve of light intensity, and setting a historical target period and multiple light change detection periods; the system calculates the light characterization value within each period, and calculates and obtains the light change coefficient, and compares it with a preset threshold to judge the frequency of light change; based on the analysis result of light change, the system optimizes the voltage regulation strategy; if the light change is frequent but stable, the system calculates the average value of the light intensity within the target period as the benchmark for adjusting the brightness, reduces unnecessary brightness adjustment, and reduces energy consumption; if the light change is unstable, the system determines a light intensity fluctuation range, and only adjusts the LED brightness according to the real-time light intensity within this range; when the ambient light exceeds this range, the system maintains the current brightness unchanged to avoid over-regulation; the present invention realizes the dynamic adjustment of the brightness of the LED warning screen through intelligent perception and analysis of ambient light changes, which not only ensures the warning effect but also effectively saves energy and improves the overall performance of the system.

[0105] Embodiment 3:

[0106] Based on Embodiment 1 and Embodiment 2, an intelligent dimming system for an LED warning screen described in an embodiment of the present invention is exemplarily applied to an outdoor traffic warning screen application scenario:

[0107] Application scenario:

[0108] It is applicable to the LED traffic warning screen at urban road intersections, which needs to work stably in an environment with large day-night temperature differences and frequent light intensity changes (such as strong light during morning and evening rush hours, weak light on cloudy days, and glare from vehicle lights at night), ensuring that warning information is clearly visible while reducing energy consumption;

[0109] System configuration:

[0110] LED warning screen body: Adopt high-brightness lens lamp beads, and the surface is coated with an anti-glare coating to improve the display effect under strong light; the screen size is 2m×1m, integrating 1000 LED lamp beads, and 50 groups are independently controlled for voltage;

[0111] Intelligent dimming controller: Installed on the top of the screen body, using a full-spectrum sensor, which can detect the light intensity in the range of 20-20000 lux, with a detection accuracy of ±5 lux and a real-time sampling frequency of 10 Hz;

[0112] Microprocessor: Select a low-power ARM Cortex-M4 chip, built-in real-time operating system (RTOS), supporting multitasking (light analysis, voltage regulation, communication interface);

[0113] Voltage regulation module: Adopt a PWM (pulse width modulation) controller, supporting 0-5V voltage output with a resolution of 0.1V, and capable of independently adjusting the voltage of each group of lamp beads;

[0114] Light fluctuation analysis module: Preset the historical target period to 24 hours, including 8640 light change detection cycles (each cycle is 10 seconds); Select the db4 wavelet basis function for wavelet decomposition, and the filter length L = 4;

[0115] Adjustment and optimization module: Set the sliding detection cycle to 1 minute, and set the sliding change coefficient threshold to 0.3 (empirical value, determined through on-site debugging);

[0116] Workflow:

[0117] 1. Light detection and curve drawing:

[0118] The light sensor collects the ambient light intensity every 10 seconds (for example, during the morning rush hour from 7:00 to 9:00, the light intensity suddenly rises from 500 lux (cloudy day) to 1500 lux (sunny day), and stabilizes below 100 lux from 22:00 to 6:00 at night), and draws the time-light intensity curve;

[0119] 2. Calculation of light cycle characterization value:

[0120] Taking 10 seconds as the detection cycle, calculate the area enclosed by the light curve and the time axis within each cycle (for example, within a certain cycle, the light intensity linearly rises from 800 lux to 1200 lux, and the area is (800 + 1200) / 2×10 = 10000 lux·s), generating a sequence S containing 8640 values;

[0121] 3. Analysis of light change coefficient:

[0122] After normalizing the sequence S, perform wavelet decomposition and calculate the light change coefficient E; for example, at noon on a sunny day, E = 200 (exceeding the threshold of 150), generating a "frequent light change signal";

[0123] 4. Stability judgment and adjustment strategy:

[0124] Daytime strong light fluctuation (stable scenario): For example, from 12:00 to 14:00 at noon, the ratio of the length of the light intensity sliding characterization value change curve to the time period duration within the sliding detection period is 0.2 (≤ the threshold 0.3), generating a "stable change signal"; the system calculates the average light intensity within 2 hours (1800 lux), stabilizes the lamp bead voltage at 3.5V (corresponding to 80% brightness), and reduces the flicker by adjusting the frequency from 10Hz to 1Hz;

[0125] Nighttime vehicle headlight interference (unstable scenario): For example, when a vehicle passes by, the light intensity suddenly rises from 50 lux to 500 lux (lasting for 5 seconds), and the sliding change coefficient is 0.4 (> the threshold 0.3), generating a "unstable change signal"; the system extracts the light data in the past 10 minutes, takes the first quartile value (30 lux) and the third quartile value (200 lux) after sorting, sets the fluctuation range [30, 200], and when the light exceeds 200 lux (such as when the vehicle headlight shines directly), maintains the current voltage (2.5V, brightness 50%) to avoid visual fatigue caused by frequent dimming;

[0126] Application effect:

[0127] Warning effect: In heavy rain weather (light intensity 500 lux), the brightness automatically increases to 90% to ensure clear visibility at 50 meters away; at night when there is no vehicle, the brightness drops to 30% to reduce light pollution;

[0128] Energy consumption optimization: Compared with the traditional fixed brightness mode, the daily average power consumption is reduced by 40%, and the LED lifespan is extended by more than 20%.

[0129] Example 4:

[0130] Based on Example 1 and Example 2, an intelligent dimming system for an LED warning screen described in an embodiment of the present invention is exemplarily applied to the application scenario of a construction site warning screen:

[0131] Application scenario:

[0132] Suitable for LED safety warning screens at construction sites, facing complex environments such as strong light (welding arc light, construction vehicle headlights), dust pollution, and high-frequency light intensity fluctuations (equipment start-stop, cloud cover), it is required to maintain stable display under harsh conditions while reducing the damage to the equipment caused by voltage fluctuations;

[0133] System configuration:

[0134] LED warning screen body: Adopt a screen body with an IP65 protection level, and the surface of the lamp beads is covered with a dust-proof coating; integrate 500 LED lamp beads, divided into 20 groups for control, and support single-group fault isolation;

[0135] Intelligent dimming controller:

[0136] Light sensor: Equipped with a dust cover, detection range 10 - 10000 lux, anti-high light saturation threshold 15000 lux, sampling frequency 5 Hz (adapting to low-frequency fluctuations on the construction site);

[0137] Microprocessor: Integrated with an edge computing module, supports local storage of 72 hours of light data, and built-in anomaly detection algorithms (such as continuous high-light timeout alarm);

[0138] Voltage regulation module: Adopts a DC-DC buck converter, supports wide voltage input (12 - 24V), output accuracy ±0.05V, and has a surge protection function;

[0139] Light fluctuation analysis module: The historical target period is set to 12 hours (construction period), detection period 30 seconds; Haar wavelet is selected for wavelet decomposition to improve calculation speed;

[0140] Adjustment and optimization module: Sliding detection period 5 minutes, sliding change coefficient threshold 0.4 (adapting to high-frequency noise on the construction site);

[0141] Workflow:

[0142] 1. High-light interference detection:

[0143] When the welding equipment is started, the light sensor detects that the light intensity suddenly rises to 8000 lux (lasting for 2 minutes), and draws a real-time curve to show high-frequency spike fluctuations;

[0144] 2. Processing of light cycle characterization value:

[0145] Taking 30 seconds as a cycle, calculate the light area during the welding period (for example, in a certain cycle, the peak is 8000 lux, the average value is 5000 lux, and the area is 5000×30 = 150000 lux·s), and generate sequence S;

[0146] 3. Coefficient of variation calculation and signal generation:

[0147] After normalizing sequence S, perform Haar wavelet decomposition, calculate E = 300 (far exceeding the threshold 100), and generate a "frequent light change signal";

[0148] 4. Dynamic adjustment strategy:

[0149] Stable high-light period (such as noon on a sunny day): During the sliding detection period, the ratio of the length of the light sliding characterization value change curve to the period is 0.3 (≤ threshold 0.4), generating a "stable change signal"; The system takes the 1-hour average value (6000 lux), adjusts the voltage to 4.0V (brightness 90%), and enables the "high-light protection mode", detecting the temperature of the lamp beads every 10 minutes, and automatically reducing the power by 10% when overheating;

[0150] Unstable Fluctuation Period (such as equipment startup and shutdown): When the sliding change coefficient is 0.5 (> the threshold value of 0.4), extract the illumination data of the past 30 minutes, sort it, and take the first quartile value (2000 lux) and the third quartile value (7000 lux), and set the fluctuation range as [2000, 7000]; when the illumination is lower than 2000 lux (such as when the equipment is turned off), the voltage gradually drops to 3.0 V (brightness 60%); if it exceeds 7000 lux briefly (such as direct arc light), maintain the current voltage for 5 seconds to avoid false adjustment triggered by instantaneous strong light;

[0151] Application Effect:

[0152] Anti-interference Ability: Effectively filter the instantaneous strong light of the welding arc (lasting < 1 second) to avoid misjudging it as environmental illumination change; when the sensor is covered with dust, predict and compensate through historical data to ensure the adjustment accuracy;

[0153] Equipment Protection: The voltage regulation frequency is reduced from 5 Hz to 0.5 Hz (within the fluctuation range), reducing the loss of the PWM controller, and the failure rate under the complex electromagnetic environment on the construction site is reduced by 30%.

[0154] Example 5:

[0155] Based on Example 1 and Example 2, for the intelligent dimming system of an LED warning screen described in the embodiments of the present invention, an exemplary application scenario is the warning screen in an underground parking lot:

[0156] Application Scenario:

[0157] Suitable for the LED guiding warning screen in an underground parking lot, the environmental characteristics are low illumination (50 - 500 lux), dynamic illumination (vehicle entry and exit lights, bend shadows), and multiple reflection surfaces (wall and ground reflections). It is necessary to achieve smooth dimming under the illumination gradient change to avoid visual discomfort for the human eye;

[0158] System Configuration:

[0159] LED Warning Screen Body: Adopt low-power lamp beads, with a peak brightness of 600 lux, supporting linear brightness adjustment from 1% to 100%; the surface of the screen body is a diffuse reflection material to reduce reflection interference;

[0160] Intelligent Dimming Controller:

[0161] Light Sensor: Adopt a dual-sensor design (direct light + diffused light detection), with a detection range of 5 - 1000 lux, a resolution of 1 lux, and a sampling frequency of 20 Hz (to capture fast vehicle lights);

[0162] Microprocessor: Integrate the visual comfort algorithm, set the brightness change rate threshold (≤ 10% / second) to avoid sudden brightness changes;

[0163] Voltage regulation module: Adopts a linear voltage regulator with an output noise ≤ 10 mV to ensure no flicker during the dimming process;

[0164] Light intensity fluctuation analysis module: For the historical target period of 8 hours (peak period in the parking lot), the detection period is 5 seconds; Symlets wavelet (sym8) is selected for wavelet decomposition to optimize the analysis of low-frequency signals;

[0165] Adjustment and optimization module: The sliding detection period is 2 minutes, and the threshold of the sliding change coefficient is 0.2 (to adapt to the low-fluctuation environment);

[0166] Workflow:

[0167] 1. Dynamic light capture:

[0168] When a vehicle enters, the light sensor detects that the light intensity suddenly rises from 100 lux (normal state in the parking lot) to 300 lux (direct headlight illumination, lasting for 10 seconds), and then drops to 150 lux (shadow in the curve), and a high-frequency fluctuation curve is plotted;

[0169] 2. Calculation of periodic characterization value and change coefficient:

[0170] Taking 5 seconds as a period, calculate the light area within each period (such as the area of the direct headlight illumination period = (100 + 300) / 2 × 5 = 1000 lux·s) to generate a sequence S; after normalization, perform sym8 wavelet decomposition, calculate the energy of the detail coefficient E = 80 (exceeding the threshold of 50), and generate a "frequently changing light signal";

[0171] 3. Stability analysis and adjustment strategy:

[0172] Stable low-light period (such as non-peak period): During the sliding detection period, the ratio of the length of the light sliding characterization value change curve to the period is 0.15 (≤ the threshold of 0.2), generating a "stable change signal"; the system takes the average value of 30 minutes (120 lux), adjusts the voltage to 2.0 V (brightness 40%), reduces the adjustment frequency to 5 Hz, and simultaneously enables the "human eye comfort mode" with the brightness change rate limited to 5% / second;

[0173] Unstable vehicle light interference: When the sliding change coefficient is 0.3 (> the threshold of 0.2), extract the light data of the recent 10 minutes, sort them, and take the first quartile value (80 lux) and the third quartile value (200 lux) to set the fluctuation range [80, 200]; when the light is within the range (such as when the vehicle is moving slowly), linearly adjust the voltage according to the real-time intensity; if it exceeds 200 lux briefly (such as a strong spotlight), maintain the current brightness for 10 seconds (waiting for the vehicle to pass) to avoid frequently increasing the brightness due to instantaneous strong light;

[0174] Application effect:

[0175] Visual experience: The brightness change is smooth without flicker, and the driver has no discomfort from glare when entering and exiting the curve; warning information is clear under low light (for example, the brightness of the "exit guide" sign is stable at 40%);

[0176] Energy-saving effect: Compared with the traditional fixed 50% brightness mode, the daily average power consumption is reduced by 50%. In combination with the linkage of the parking lot management system (such as parking space guidance), the dimming strategy can be further optimized.

[0177] The above has described a specific embodiment of the present invention in detail. However, the described content is only a preferred embodiment of the present invention and cannot be considered as limiting the scope of implementation of the present invention. All equivalent changes and improvements made according to the scope of the present invention application should still fall within the scope covered by the patent of the present invention.

Claims

1. An intelligent dimming system for an LED warning screen, characterized in that, It includes an LED warning screen body and an intelligent dimming controller; The intelligent dimming controller includes a light sensor, a voltage regulation module, a microprocessor, a light fluctuation analysis module, and an adjustment optimization module; The light sensor is used to detect the light intensity of the surrounding environment in real time and generate a light intensity signal; The microprocessor is used to receive the light intensity signal and adjust the working voltage of the LED lamp beads in the LED warning screen body through the voltage regulation module; The light fluctuation analysis module analyzes the change of ambient light based on the real-time light intensity and generates a frequent light change signal; The process of analyzing the change of ambient light based on the real-time light intensity and generating a frequent light change signal is as follows: Based on the two-dimensional coordinate system with time as the X-axis and light intensity as the Y-axis, draw the real-time change curve of light intensity; Preset a historical target period, and the historical target period includes multiple light change detection cycles; Based on the real-time change curve of the light intensity, obtain the light cycle characterization values within each light change detection period, so as to obtain a sequence of light cycle characterization values: , where N represents the length of the sequence of light cycle characterization values; The process of obtaining the light cycle characterization value is as follows: Extract the area enclosed by the real-time light intensity change curve and the X-axis within the light change detection cycle, and mark it as the light cycle characterization value; Based on the light cycle characterization value sequence, perform normalization processing and wavelet decomposition on the light cycle characterization value sequence to obtain the light change coefficient; Preset a light change coefficient threshold, and compare and analyze the light change coefficient with the light change coefficient threshold; If the light change coefficient is greater than the light change coefficient threshold, generate a frequent light change signal; The adjustment optimization module analyzes the stability of the light change based on the frequent light change signal to optimize the adjustment frequency and voltage adjustment value of the voltage regulation module for the working voltage of the LED lamp beads.

2. The intelligent dimming system of an LED warning screen according to claim 1, characterized in that The light sensor is used to detect the light intensity of the surrounding environment in real time, thereby generating a light intensity signal based on the light intensity and sending the detected light intensity signal to the microprocessor.

3. The intelligent dimming system of an LED warning screen according to claim 2, characterized in that, The microprocessor adjusts the working voltage of the LED lamp beads through the voltage regulation module according to the received light intensity signal, thereby changing the brightness of the LED lamp beads.

4. The intelligent dimming system of an LED warning screen according to claim 1, characterized in that, The process of obtaining the light change coefficient based on the light cycle characterization value sequence is as follows: Perform normalization processing on the light cycle characterization value sequence; Use the wavelet basis function to perform wavelet decomposition on the normalized light cycle characterization value sequence to obtain the detail coefficients. The specific process is as follows: The preset normalized light cycle characterization value sequence is , where the value of n is 1, 2, ……, N; By the formula: , the detail coefficient is calculated and obtained; where L is the length of the filter, k is the summation index, and its value range is from 0 to L - 1, which is the coefficient of the high-pass filter in the wavelet decomposition process; Obtained by the formula: , the light change coefficient E is calculated.

5. The intelligent dimming system of an LED warning screen according to claim 1, characterized in that, The process of analyzing the stability of the light change based on the frequent light change signal to optimize the adjustment frequency and voltage adjustment value of the voltage regulation module for the working voltage of the LED lamp beads is as follows: Based on the frequent light change signal, preset a sliding detection period; Based on the sliding detection period within the historical target period, obtain the light sliding cycle characterization value of the sliding detection period; Then, based on the light sliding cycle characterization value of the sliding detection period, calculate the sliding change coefficient of the historical target period. The specific process is as follows: Based on the two-dimensional coordinate system with time as the X-axis and the light sliding cycle characterization value as the Y-axis, draw the change curve of the light sliding cycle characterization value; Extract the length of the change curve of the light intensity sliding period characterization value, calculate the difference from the historical target period duration characterization length, and take the absolute value to obtain the sliding change characterization length. Then calculate the ratio of the sliding change characterization length to the historical target period duration characterization length to obtain the sliding change coefficient; Among them, the historical target period duration characterization length is expressed as the length of the historical target period duration in a two-dimensional coordinate system with time as the X-axis and the light intensity sliding period characterization value as the Y-axis; Preset a sliding change coefficient threshold, and conduct a comparative analysis of the sliding change coefficient and the sliding change coefficient threshold; If the sliding change coefficient is less than or equal to the sliding change coefficient threshold, generate a change stable signal; If the sliding change coefficient is greater than the sliding change coefficient threshold, generate a change unstable signal; Based on the change stable signal and the change unstable signal respectively, optimize the adjustment frequency and voltage adjustment value of the voltage adjustment module for adjusting the working voltage of the LED lamp beads.

6. The intelligent dimming system of an LED warning screen according to claim 5, characterized in that, The process of optimizing the adjustment frequency and voltage adjustment value of the voltage adjustment module for adjusting the working voltage of the LED lamp beads based on the change stable signal is as follows: Based on the change stable signal, extract the average value of the real-time ambient light intensity at each time point within the target period to obtain the light intensity average value. Then generate a light intensity signal based on the light intensity average value and send the light intensity signal to the microprocessor. The microprocessor adjusts the working voltage of the LED lamp beads through the voltage adjustment module according to the received light intensity signal, thereby changing the brightness of the LED lamp beads.

7. The intelligent dimming system of an LED warning screen according to claim 5, characterized in that The process of optimizing the adjustment frequency and voltage adjustment value of the voltage adjustment module for adjusting the working voltage of the LED lamp beads based on the change unstable signal is as follows: Based on the change unstable signal, extract the real-time ambient light intensity at each time point within the target period, sort the real-time ambient light intensity in ascending order according to the magnitude of the real-time ambient light intensity value to obtain the real-time ambient light intensity sequence, and extract the first quartile value and the third quartile value of the real-time ambient light intensity sequence, thereby obtaining the light intensity fluctuation range; Among them, the upper limit of the light intensity fluctuation range is the third quartile value of the real-time ambient light intensity sequence, and the lower limit of the light intensity fluctuation range is the first quartile value of the real-time ambient light intensity sequence; Based on the light intensity fluctuation range, adjust the brightness of the LED lamp beads in real time. When the ambient light intensity exceeds the light intensity fluctuation range, do not adjust the working voltage of the LED lamp beads.

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