LED lamp adaptive speed regulation heat dissipation method and system based on real-time junction temperature monitoring and medium

Abstract

The invention provides an LED lamp adaptive speed regulation heat dissipation method and system based on real-time junction temperature monitoring. The method comprises the following steps: S100, acquiring a PWM signal or an analog signal of an LED driving command signal in real time; s200, on the basis of the change of the driving instruction signal, feedforward prediction is carried out by using a dynamic thermal inertia mapping model, and a feedforward fan control quantity is generated; s300, LED junction temperature is monitored in real time through a forward voltage method, and feedback fan control quantity is generated through a feedback controller according to the deviation between the real-time junction temperature and the target junction temperature; and S400, synthesizing the feedforward control quantity and the feedback control quantity to generate a fan PWM control signal, outputting the fan PWM control signal to a fan driving circuit, and adjusting the rotating speed of the cooling fan. According to the method, driving signals and junction temperature information are processed in parallel, and feedforward and feedback control is combined, so that self-adaptive accurate regulation and control are realized, thermal load change is quickly responded, system lag is effectively inhibited, and LED heat dissipation performance is optimized.

Description

Technical Field

[0001] This application relates to the field of LEDs, and in particular to an adaptive speed-regulating heat dissipation method system and medium for LED lamps based on real-time junction temperature monitoring. Background Technology

[0002] LED lighting fixtures have become dominant in the general lighting field due to their high energy efficiency, long lifespan, and environmental friendliness. However, the performance and lifespan of LEDs are closely related to their core operating temperature—the junction temperature. Excessively high junction temperatures can directly lead to severe light decay, color shift, and even permanent damage to LEDs. Industry experience shows that for every 10°C reduction in junction temperature, the lifespan of an LED can potentially double. Therefore, efficient and reliable thermal management is crucial for ensuring the performance and lifespan of LED lighting fixtures.

[0003] Existing heat dissipation solutions for LED lighting fixtures are mainly divided into two categories: passive heat dissipation and active heat dissipation. For low-to-medium power lighting fixtures, passive heat dissipation methods such as aluminum alloy heat sinks are commonly used, but their heat dissipation capacity is limited and they cannot cope with dynamically changing heat loads. For high-power lighting fixtures or high-performance lighting fixtures that require a compact structure, active heat dissipation solutions with enhanced fans are generally adopted.

[0004] Currently, active cooling control based on real-time temperature monitoring has become a mainstream technology for improving heat dissipation efficiency. This type of technology typically uses temperature sensors (such as thermistors) to monitor the temperature at a specific point on the lamp housing or heat sink, and then uses a microcontroller to dynamically adjust the fan speed based on this temperature value using algorithms such as proportional-integral-derivative (PI-DE) control. This closed-loop feedback control method, compared to fixed-speed cooling, improves heat dissipation performance and energy consumption to a certain extent.

[0005] However, this control system based on peripheral temperature feedback has inherent technical defects: since the monitored peripheral temperature is not the junction temperature itself, and there is a significant thermal delay in the heat conduction from the chip to the sensor, the system can only perform lagging and indirect temperature control, making it difficult to accurately stabilize the junction temperature. Moreover, the aggressive control parameters set to compensate for this delay are prone to causing oscillations and overshoots in fan speed and temperature, which can ultimately lead to instantaneous peaks in junction temperature that damage lifespan when the thermal load changes drastically.

[0006] In recent years, in pursuit of more precise control, the industry has proposed methods for directly monitoring LED junction temperature, such as measuring the negative correlation between forward voltage and junction temperature. However, even with direct junction temperature feedback, the control logic is essentially still "remedial" in nature. When an LED experiences a sudden and significant increase in brightness, resulting in a massive instantaneous heat load, the pure feedback system still cannot overcome its inherent physical response delay, and the problems of response lag and instantaneous overshoot remain unresolved.

[0007] Therefore, there is an urgent need in this field for an intelligent heat dissipation control method that can proactively suppress junction temperature fluctuations at the source, in order to make up for the inherent defects of traditional feedback control, achieve faster, more stable and more precise control of LED junction temperature, thereby fully releasing the performance potential of LED and ensuring its ultra-long service life. Summary of the Invention

[0008] The purpose of this application is to provide an adaptive speed-regulating heat dissipation method for LED lamps based on real-time junction temperature monitoring.

[0009] According to one aspect of this application, an adaptive speed-regulating heat dissipation method for LED lamps based on real-time junction temperature monitoring is provided, comprising the following steps: S100 acquires the LED driving command signal in real time. The driving command signal is a PWM signal or an analog level signal used to control the LED brightness or current. Based on the changes in the drive command signal, S200 uses the dynamic thermal inertia mapping model stored in the pre-stored memory to perform feedforward prediction and generate the corresponding feedforward fan control quantity. S300 monitors the junction temperature of the LED in real time using the forward voltage method, and generates a feedback fan control quantity through the feedback controller based on the deviation between the monitored real-time junction temperature and the preset target junction temperature. S400 combines the feedforward fan control signal and the feedback fan control signal to generate the final fan PWM control signal, and outputs it to the fan drive circuit to drive the cooling fan to adjust the speed and dissipate heat from the LED.

[0010] In one specific embodiment, in step S200, the "based on the change of the driving command signal" specifically means: calculating in real time the change of the instantaneous value of the driving command signal relative to the value at the previous moment; when the absolute value of the change exceeds a preset amplitude threshold, and / or the rate of change per unit time exceeds a preset rate threshold, the feedforward prediction is triggered.

[0011] In one specific embodiment, the dynamic thermal inertia mapping model is a linear or nonlinear mathematical model that describes the mapping relationship between the change in driving command and the expected change in junction temperature. The model includes at least two key parameters: thermal capacity gain and thermal time constant. The thermal capacity gain characterizes the steady-state change in junction temperature caused by a unit change in driving command, and the thermal time constant characterizes the response speed of the junction temperature change.

[0012] In one specific embodiment, the "real-time monitoring by forward voltage method" in step S300 specifically includes switching the drive current to a constant, microamp-level measurement current by means of an analog switch during the preset turn-off gap of the LED pulse drive current. The forward voltage drop across the LED is quickly sampled using an analog-to-digital converter. The current real-time junction temperature is calculated based on a pre-stored voltage-temperature lookup table or fitting formula obtained through calibration.

[0013] In one specific embodiment, in step S300, the feedback controller is a proportional-integral-derivative controller, which calculates the feedback fan control quantity based on the deviation between the real-time junction temperature and the target junction temperature through a combination of proportional, integral, and derivative operations.

[0014] In one specific embodiment, in step S400, the "synthesis" is to linearly superimpose the feedforward fan control quantity and the feedback fan control quantity in an algebraic manner, and limit the superposition result to a preset PWM duty cycle output range.

[0015] In one specific embodiment, the method further includes step S500: The junction temperature change curve predicted by the dynamic thermal inertia mapping model is periodically compared with the junction temperature change curve actually monitored by the forward voltage method; based on the residual between the two, the parameters of the dynamic thermal inertia mapping model are fine-tuned and optimized online by recursive least squares method or gradient descent method.

[0016] According to another aspect of this application, an adaptive speed-regulating heat dissipation system for LED lamps is provided, comprising a microcontroller, a drive command monitoring module, a junction temperature monitoring module, and a fan drive module. The microcontroller serves as the core computing and control unit of the system; the drive command monitoring module is connected to the input port of the microcontroller and the LED drive circuit, and is used to acquire the drive command signal in real time; the junction temperature monitoring module is connected to the microcontroller and the LED chip, and is used to measure the junction temperature using the forward voltage method; the fan drive module is connected to the PWM output port of the microcontroller, and is used to receive the final fan PWM control signal and drive the cooling fan; wherein, the microcontroller is configured to execute program instructions stored therein to complete the steps of the method described above.

[0017] In one specific embodiment, the junction temperature monitoring module includes a constant current source, an analog switch, and an analog-to-digital converter. The constant current source is used to provide the constant measurement current; the analog switch, controlled by the microcontroller, is used to switch at high speed between the normal drive current path and the constant current source measurement path; the analog-to-digital converter is used to sample the forward voltage across the LED during the measurement phase and convert it into a digital signal for the microcontroller to read.

[0018] According to another aspect of this application, a computer-readable storage medium storing a computer program is provided, wherein when the computer program is executed by a processor, it implements the steps of any of the methods described above; the computer-readable storage medium includes, but is not limited to, a read-only memory, a random access memory, flash memory, a hard disk, or a solid-state drive.

[0019] Therefore, the adaptive speed regulation and heat dissipation method for LED lamps based on real-time junction temperature monitoring in this application processes the drive command signal and real-time junction temperature information in parallel, and integrates the advance feedforward control quantity based on command prediction and the precise feedback control quantity based on junction temperature monitoring in real time, thereby generating a composite fan control signal that can synchronously respond to changes in heat load and effectively suppress system lag, and finally achieves adaptive and precise regulation of the cooling fan speed. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a flowchart of an adaptive speed-regulating heat dissipation method for LED lamps based on real-time junction temperature monitoring. Detailed Implementation

[0022] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings. Preferred embodiments of this application are shown in the drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application.

[0023] It should be noted that when a component is said to be "fixed to" another component, it can be directly attached to the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0025] Please refer to Figure 1 One embodiment of this application provides an adaptive speed-regulating heat dissipation method for LED lamps based on real-time junction temperature monitoring, comprising the following steps: S100 acquires the LED driving command signal in real time. The driving command signal is a PWM signal or an analog level signal used to control the LED brightness or current. Based on the changes in the drive command signal, S200 uses the dynamic thermal inertia mapping model stored in the pre-stored memory to perform feedforward prediction and generate the corresponding feedforward fan control quantity. S300 monitors the junction temperature of the LED in real time using the forward voltage method, and generates a feedback fan control quantity through the feedback controller based on the deviation between the monitored real-time junction temperature and the preset target junction temperature. S400 combines the feedforward fan control signal and the feedback fan control signal to generate the final fan PWM control signal, and outputs it to the fan drive circuit to drive the cooling fan to adjust the speed and dissipate heat from the LED.

[0026] Step S100 describes how to acquire the LED drive command signal in real time, mainly used to control the LED's brightness or current. This drive signal is typically a PWM (Pulse Width Modulation) signal or an analog level signal. These signals control the LED's operating state, such as brightness adjustment or current changes, directly affecting the LED's heat generation. Specifically: PWM signal: When controlling LED brightness, the PWM signal adjusts the brightness by regulating the duty cycle (i.e., the ratio of the duration of the high-level signal to the total cycle). This method can maintain high brightness even with low power consumption, thus affecting the heat generation of the LED.

[0027] Analog level signals: In some cases, the drive current of an LED can also be adjusted using analog level signals. This adjustment method is smoother than PWM signals and can reduce the impact of current fluctuations on the LED, but it may not be as efficient as PWM.

[0028] Real-time acquisition: Real-time acquisition of drive command signals means that the control system continuously monitors signal changes during LED operation. This is crucial for ensuring the real-time response of the LED heat dissipation system.

[0029] By acquiring drive command signals, the system can instantly reflect the working status of the LED, providing accurate input information for subsequent heat dissipation control and ensuring the temperature control efficiency of the LED under various workloads.

[0030] In step S200, the system performs feedforward prediction based on the changes in the drive command signal obtained in step S100, using the dynamic thermal inertia mapping model in memory. Specifically, this model predicts the LED junction temperature change trend by analyzing the relationship between past changes in the drive command signal and changes in the LED junction temperature, and generates corresponding feedforward fan control quantities. Wherein: Dynamic thermal inertia mapping model: This model is typically described by several key parameters (such as thermal capacity gain, thermal time constant, etc.). These parameters are used to predict the response speed and stability of the LED junction temperature under different driving command variations. The model can predict the short-term trend of LED junction temperature changes based on real-time changing driving signals.

[0031] Feedforward control: Feedforward control is a preventative control method that adjusts the fan speed in advance based on predicted trends before the LED junction temperature changes significantly. Through feedforward prediction using a dynamic thermal inertia mapping model, the fan can be activated for cooling before the junction temperature becomes too high.

[0032] The purpose of this step is to enable the fan to adjust in advance according to the changing trend of the LED drive signal through feedforward prediction, so as to avoid the LED temperature from exceeding the safe range in subsequent changes, thereby improving heat dissipation efficiency and preventing the LED from being damaged or degraded due to overheating.

[0033] In step S300, the system monitors the LED junction temperature in real time using the forward voltage method. There is a certain relationship between the LED junction temperature and its forward voltage; the system uses this relationship to calculate the junction temperature by measuring the voltage drop across the LED. Simultaneously, based on the deviation between the monitored junction temperature and the preset target junction temperature, the feedback controller generates a feedback fan control signal to adjust the fan speed and maintain the LED junction temperature within the target range. Specifically: Forward voltage method: The forward voltage method estimates the junction temperature of an LED by applying a small, constant current through its operating current path and measuring the voltage change across the LED. This method offers high accuracy and low cost, making it suitable for real-time monitoring of LED junction temperature.

[0034] Feedback Controller: A feedback controller (such as a PID controller) calculates the necessary adjustment based on the deviation between the current junction temperature of the LED and the target junction temperature. The larger this deviation, the greater the adjustment in fan speed, ensuring that the LED junction temperature recovers to the target value as quickly as possible. By monitoring the junction temperature in real time and implementing feedback control, the LED temperature is ensured to remain stable within a safe range, thus preventing damage caused by overheating. Furthermore, feedback control can be flexibly adjusted to adapt to the needs of different operating environments and loads.

[0035] In step S400, the feedforward fan control signal and the feedback fan control signal are combined to generate the final fan PWM control signal. This signal is output to the fan drive circuit to drive the cooling fan for speed regulation and heat dissipation. Wherein: Synthesis Method: The synthesis of feedforward and feedback control variables is usually performed by weighted summation or algebraic addition. In some cases, the synthesized result may also be constrained to ensure that the duty cycle of the fan PWM signal does not exceed the maximum or minimum limit.

[0036] The final fan control signal: The generated PWM signal directly controls the fan speed, adjusting the heat dissipation effect. When the LED load is high, the feedforward control plays a more prominent role; while when the junction temperature deviation is large, feedback control takes the lead.

[0037] By synthesizing feedforward and feedback control quantities, the system can flexibly adjust the fan speed under different operating conditions, achieving more precise and efficient heat dissipation control and ensuring that LED lights maintain stable performance even after long-term operation.

[0038] In one specific embodiment, in step S200, the "based on the change of the driving command signal" specifically means: calculating in real time the change of the instantaneous value of the driving command signal relative to the value at the previous moment; when the absolute value of the change exceeds a preset amplitude threshold, and / or the rate of change per unit time exceeds a preset rate threshold, the feedforward prediction is triggered.

[0039] In one specific embodiment, the dynamic thermal inertia mapping model is a linear or nonlinear mathematical model that describes the mapping relationship between the change in driving command and the expected change in junction temperature. The model includes at least two key parameters: thermal capacity gain and thermal time constant. The thermal capacity gain characterizes the steady-state change in junction temperature caused by a unit change in driving command, and the thermal time constant characterizes the response speed of the junction temperature change.

[0040] In one specific embodiment, the "real-time monitoring by forward voltage method" in step S300 specifically includes switching the drive current to a constant, microamp-level measurement current by means of an analog switch during the preset turn-off gap of the LED pulse drive current. The forward voltage drop across the LED is quickly sampled using an analog-to-digital converter. The current real-time junction temperature is calculated based on a pre-stored voltage-temperature lookup table or fitting formula obtained through calibration.

[0041] Furthermore, to achieve accurate junction temperature monitoring, a brief off-state gap needs to be created during the LED driving process. This off-state gap is a preset period within the LED's pulsed drive current operating cycle. During this time, the LED's operating current is switched to a very low, constant measurement current, typically in the microamp range. This low current does not cause any significant thermal effect on the LED, thus allowing for accurate measurement of the LED's forward voltage drop. It is important to note that: Constant measurement current: This current is typically in the microamp range (usually a few microamps to tens of microamps) to ensure minimal temperature variation during LED operation. This method avoids the impact of the LED's own heat on measurement accuracy.

[0042] The role of the analog switch: The analog switch plays a crucial role here, switching between the LED pulse drive current and the constant measurement current. Controlled by a microcontroller, the switch accurately switches between the drive current and the measurement current according to timing, ensuring measurement accuracy and system stability.

[0043] The purpose of this process is to provide a thermally unaffected current path for accurate measurement of LED junction temperature. By separating the measurement current from the drive current and inserting a turn-off gap during LED operation, it can be ensured that the junction temperature measurement only reflects the voltage drop change of the LED under low load.

[0044] When a constant measuring current is applied across an LED, the LED's forward voltage (i.e., the voltage drop across the LED) will exhibit a certain relationship with the LED's junction temperature. At this point, rapid sampling via an analog-to-digital converter (ADC) can convert the forward voltage drop across the LED into a digital signal. The ADC can quickly and accurately convert the analog voltage signal across the LED into a digital signal for further processing by the microcontroller. This process requires high-frequency sampling to ensure accurate capture of minute voltage changes, thereby allowing for the calculation of the accurate LED junction temperature. By using a high-precision ADC for rapid sampling, the system can acquire the forward voltage drop information across the LED in real time, providing accurate data support for subsequent temperature calculations.

[0045] Once the forward voltage information across the LED is acquired, the system can convert the forward voltage into the corresponding junction temperature value using a pre-stored voltage-temperature lookup table or fitting formula. This lookup table or formula accurately converts the LED's forward voltage drop into a junction temperature value. This allows the system to obtain precise LED junction temperature data in real-time monitoring, providing crucial reference information for subsequent feedback control.

[0046] In one specific embodiment, in step S300, the feedback controller is a proportional-integral-derivative controller, which calculates the feedback fan control quantity based on the deviation between the real-time junction temperature and the target junction temperature through a combination of proportional, integral, and derivative operations.

[0047] Furthermore, the core task of the feedback controller is to take the deviation between the real-time junction temperature and the target junction temperature as input, and output a feedback fan control quantity through a control algorithm (in this case, a PID control algorithm) to adjust the fan speed, thereby effectively controlling the LED junction temperature. The PID controller is a feedback controller widely used in automatic control systems. Its principle is to generate an adjustment signal by calculating the proportional, integral, and derivative of the temperature deviation. Specifically: Proportion (P): Adjusts the fan speed based on the current junction temperature deviation; the larger the deviation, the larger the adjustment.

[0048] Integral (I): Adjust the fan speed based on the cumulative value of the junction temperature deviation to prevent the system from having small temperature deviations (such as steady-state errors) for a long time.

[0049] Differential (D): Adjusts the fan speed based on the rate of change of the junction temperature deviation, used to slow down over-adjustment when the temperature rises sharply and to avoid excessive fan response.

[0050] Assuming the real-time junction temperature is Treal and the target junction temperature is Ttarget, then the junction temperature deviation ΔT is:

[0051] Based on the structure of the PID controller, the feedback fan control quantity Cfeedbac consists of three parts: ; in: Kp is the proportional gain, which controls the system's response speed; Ki is the integral gain, which helps to eliminate steady-state error; Kd is the differential gain, which reduces over-adjustment due to temperature changes.

[0052] The calculated feedback fan control quantity Cfeedback is used as an input signal and converted into a PWM signal for the fan by the microcontroller. The PWM signal controls the fan speed, thereby adjusting the cooling effect.

[0053] The feedback fan control output calculated using a PID controller can precisely adjust the fan speed based on the deviation between the real-time junction temperature and the target junction temperature. Through the coordination of the proportional, integral, and derivative components, the system can effectively cope with changes in LED junction temperature, preventing excessively high or low temperatures and ensuring long-term stable operation of the LED.

[0054] In practical applications, the parameters (Kp, Ki, Kd) of a PID controller typically need to be tuned and optimized to ensure fast and stable system response. When adjusting these parameters, the following situations may arise: Excessive response: If the proportional gain is too large, the system may respond too quickly, leading to large temperature fluctuations. Long-term deviation: If the integral gain is too large, the system may over-adjust, resulting in prolonged oscillations. Slow response: If the derivative gain is too small, the system may not respond quickly enough to temperature changes, leading to delayed adjustments. To ensure optimal performance of the control system, these parameters can be optimized through experimental tuning or adaptive control algorithms to ensure the system is always in an optimal state.

[0055] The feedback fan control quantity calculated by the PID controller can be precisely adjusted based on the deviation between the real-time junction temperature and the target junction temperature. This control method effectively addresses junction temperature changes during LED operation, ensuring the temperature remains within the target range, thereby guaranteeing stable LED operation and optimizing the cooling fan's adjustment effect. The coordination of the proportional, integral, and derivative components of the PID controller gives the system strong adaptability and accuracy, meeting the needs of different application scenarios.

[0056] In one specific embodiment, in step S400, the "synthesis" is to linearly superimpose the feedforward fan control quantity and the feedback fan control quantity in an algebraic manner, and limit the superposition result to a preset PWM duty cycle output range.

[0057] Furthermore, in step S400, the feedforward fan control signal and the feedback fan control signal first need to be synthesized to generate the final fan PWM control signal. The synthesis method is a linear superposition through algebraic addition, i.e.:

[0058] in: Cfinal is the final fan control signal (used to generate the PWM signal), which is the overall control signal for the fan.

[0059] Cfeedforward is a feedforward fan control variable that predicts LED temperature changes by changing the drive command and adjusts the fan in advance.

[0060] Cfeedback is a feedback fan control variable that adjusts the fan speed based on the deviation between the real-time junction temperature and the target junction temperature.

[0061] The advantage of this synthesis method is that feedforward control can respond to temperature change trends in advance, while feedback control can adjust and correct deviations in a timely manner, making the system more stable and accurate in dynamic processes.

[0062] Feedforward control provides pre-emptive fan adjustment by predicting temperature changes, while feedback control adjusts according to actual conditions. Through this linear superposition, the system can achieve more precise fan adjustment under different operating conditions. Feedforward control helps to respond quickly to changes, while feedback control helps to handle uncertainties and sudden changes, enabling the system to operate stably under different loads and temperatures.

[0063] The synthesized fan control quantity, Cfinal, needs to be limited to ensure the fan operates within a reasonable range, avoiding excessively high or low speeds. The duty cycle of the PWM signal determines the fan speed, typically ranging from 0% to 100%, representing the speed from minimum to maximum. By limiting the control quantity within a preset duty cycle range, problems caused by excessively high or low fan speeds can be avoided. For example, excessively high speeds generate excessive noise, while excessively low speeds may lead to insufficient heat dissipation, affecting the lifespan and performance of the LEDs. This limitation ensures that the fan can smoothly adjust according to actual needs and always operate within a safe and effective operating range. Finally, the limited fan control quantity, Cfinal, is converted into a PWM signal and transmitted to the fan drive circuit through the microcontroller's PWM output port. The fan drive circuit controls the fan speed according to the PWM signal, thereby regulating LED heat dissipation. Through the final PWM signal output, the fan can adjust based on the combined results of feedforward and feedback control, maintaining the LED temperature within the set target range, preventing damage caused by overheating, and ensuring efficient and stable heat dissipation.

[0064] In one specific embodiment, the method further includes step S500: The junction temperature change curve predicted by the dynamic thermal inertia mapping model is periodically compared with the junction temperature change curve actually monitored by the forward voltage method; based on the residual between the two, the parameters of the dynamic thermal inertia mapping model are fine-tuned and optimized online by recursive least squares method or gradient descent method.

[0065] Furthermore, the key operation in step S500 is to periodically compare the junction temperature change curve predicted by the dynamic thermal inertia mapping model with the junction temperature change curve actually monitored using the forward voltage method. This comparison process aims to determine the deviation between the model prediction and the actual monitoring. It is important to note that the junction temperature change curve predicted by the dynamic thermal inertia mapping model is generated by the previously described model. This model typically predicts the LED junction temperature change based on changes in LED driving commands (such as changes in current or PWM signals). Since the model is based on historical data and known thermal inertia characteristics, it can estimate the trend of LED junction temperature change over time. The actually monitored junction temperature change curve, on the other hand, is calculated by monitoring the voltage drop across the LED in real time and based on the voltage-temperature relationship. It reflects the junction temperature change of the LED during actual operation under the influence of factors such as temperature changes, external environment, and load. By comparing these two curves, the residual (i.e., the difference between the predicted temperature and the actual temperature) can be calculated, thereby identifying model errors and deviations. The purpose of this step is to evaluate the predictive accuracy of the dynamic thermal inertial mapping model and adjust the model based on real-time data to more accurately reflect the junction temperature changes of the LED. Through continuous comparison and feedback, the system can gradually improve the accuracy of temperature prediction, thereby improving the overall efficiency of heat dissipation control. Once the residual between the model prediction and actual monitoring is calculated, the next step is to fine-tune and optimize the key parameters of the model online using recursive least squares or gradient descent. By optimizing the parameters of the dynamic thermal inertial mapping model online, the system can continuously reduce prediction errors and improve the model's accuracy. This makes the LED temperature prediction more consistent with the actual working environment, further improving the accuracy of heat dissipation control and preventing LED overheating or low-temperature operation. Online optimization allows the system to gradually adapt to different environments and conditions during actual use, improving overall temperature control performance. Through repeated online optimization processes, the system can adapt to different working conditions, ensuring consistently efficient heat dissipation control. The system's temperature control accuracy and stability are guaranteed when facing environmental or load changes. Therefore, through the above fine-tuning and optimization, the dynamic thermal inertia mapping model will continuously approach the ideal state, thereby providing more accurate predictions for feedforward control and improving the response speed and stability of the LED lighting system. The optimized model can better handle different input signals and environmental conditions, ensuring that LED lighting fixtures maintain stable junction temperature and performance in various usage scenarios.

[0066] According to another aspect of this application, an adaptive speed-regulating heat dissipation system for LED lamps is provided, comprising a microcontroller, a drive command monitoring module, a junction temperature monitoring module, and a fan drive module. The microcontroller serves as the core computing and control unit of the system; the drive command monitoring module is connected to the input port of the microcontroller and the LED drive circuit, and is used to acquire the drive command signal in real time; the junction temperature monitoring module is connected to the microcontroller and the LED chip, and is used to measure the junction temperature using the forward voltage method; the fan drive module is connected to the PWM output port of the microcontroller, and is used to receive the final fan PWM control signal and drive the cooling fan; wherein, the microcontroller is configured to execute program instructions stored therein to complete the steps of the method described above.

[0067] Furthermore, the microcontroller is the core computing and control unit of the entire system, responsible for tasks such as all data processing, execution of control algorithms, and signal scheduling. Its main functions include: Data acquisition: Input signals are acquired in real time from the drive command monitoring module and the junction temperature monitoring module.

[0068] Calculation and control: Executes the program instructions stored within it, calculates feedforward and feedback control quantities based on the acquired signals, and synthesizes them.

[0069] PWM output: Generates the final fan PWM control signal and outputs it to the fan drive module to adjust the fan speed.

[0070] The microcontroller, with its powerful computing capabilities, can process input signals in real time and adjust the output signals according to a predetermined algorithm, ensuring that the system can adaptively adjust the fan speed based on the LED's operating status. As the core unit, the microcontroller ensures that the system can adjust in real time based on various parameters such as LED workload and junction temperature changes, effectively improving heat dissipation efficiency and preventing LED performance degradation due to overheating. The drive command monitoring module acquires LED drive command signals in real time. These signals are used to control the LED's brightness or current and are typically PWM signals or analog level signals. This module mainly connects to the microcontroller's input ports and the LED driver circuit, and has the following functions: Signal acquisition: Real-time monitoring of PWM signals or analog level signals in the LED driver circuit to obtain LED driving commands.

[0071] Signal transmission: The acquired drive command signals are transmitted to the microcontroller for subsequent calculations.

[0072] This module provides crucial drive command signals to the microcontroller, enabling the system to adjust accordingly based on the actual operating state of the LED (such as brightness and current requirements). This helps improve the response speed of the thermal control system, allowing the system to precisely adjust fan speed and avoid overheating or underheating. The junction temperature monitoring module's task is to monitor the LED's junction temperature in real time and transmit this data to the microcontroller. This module is typically connected to both the LED chip and the microcontroller, and performs junction temperature measurement using the forward voltage method. The specific working process is as follows: Constant measurement current: Within the preset off gap of the LED's pulse drive current, a constant microampere-level measurement current is switched via an analog switch.

[0073] Voltage sampling: The forward voltage drop across the LED is quickly sampled using an analog-to-digital converter to obtain voltage data related to the junction temperature.

[0074] Temperature calculation: Based on the voltage-temperature lookup table or fitting formula stored in the microcontroller, the voltage data is converted into a real-time junction temperature value and transmitted to the microcontroller.

[0075] The junction temperature monitoring module can collect LED junction temperature data in real time, providing a basis for subsequent heat dissipation control. Through precise temperature measurement, the system can adjust according to the actual operating temperature of the LED, ensuring that the LED is not damaged by overheating, thereby improving the LED's lifespan and stability.

[0076] The fan driver module is responsible for receiving the final fan PWM control signal from the microcontroller and adjusting the speed of the cooling fan accordingly. Its main functions are as follows: PWM signal reception: The fan drive module receives the final generated PWM control signal from the PWM output port of the microcontroller.

[0077] Fan control: The fan speed is controlled according to the received PWM signal to adjust the fan operation status and achieve the effect of heat dissipation.

[0078] A fan drive module typically includes a motor drive circuit that can convert PWM signals into specific fan speed adjustments, ensuring that the fan can operate under different load and temperature conditions.

[0079] In one specific embodiment, the junction temperature monitoring module includes a constant current source, an analog switch, and an analog-to-digital converter. The constant current source is used to provide the constant measurement current; the analog switch, controlled by the microcontroller, is used to switch at high speed between the normal drive current path and the constant current source measurement path; the analog-to-digital converter is used to sample the forward voltage across the LED during the measurement phase and convert it into a digital signal for the microcontroller to read.

[0080] Furthermore, the constant current source plays a crucial role in the junction temperature monitoring module, providing a stable and accurate measurement current. Its function and working principle are as follows: A constant current source generates a constant current in the microamp range (typically a few to tens of microamps), which is measured through an LED, ensuring that it does not cause significant changes in the LED junction temperature. By adjusting the current magnitude, the constant current source ensures that the current remains constant during the measurement process, avoiding temperature fluctuations caused by current variations. This makes the relationship between voltage and temperature changes measured using the forward voltage method more accurate. The constant current source provides a stable measurement current, ensuring that temperature changes during junction temperature measurement are minimized, providing accurate measurement conditions for subsequent voltage sampling.

[0081] The analog switch in the junction temperature monitoring module functions by rapidly switching between the normal drive current path and the constant current source measurement current path based on the microcontroller's control signal. Its working principle is as follows: Under normal circumstances, the driving current of an LED flows through the LED's main current path to drive the LED to emit light. However, when measuring the junction temperature, an analog switch is used to switch the normal driving current to the constant current source path, ensuring that the small measurement current provided by the constant current source is used to measure the LED's forward voltage.

[0082] The analog switch, controlled by a microcontroller, can precisely switch between normal LED operation and junction temperature measurement. This ensures that the current supplied by the constant current source is not affected by fluctuations in the normal drive current during junction temperature measurement.

[0083] The analog switch can quickly switch between the normal drive current path and the measurement current path, ensuring that the current provided by the constant current source is unique when measuring junction temperature, thus avoiding interference and errors.

[0084] The analog-to-digital converter (ADC) is the core component of the junction temperature monitoring module. It converts the forward voltage drop across the LED into a digital signal for the microcontroller to read and process. Its working principle is as follows: When a constant current source provides a stable measurement current, a forward voltage drop related to the LED junction temperature will be generated across the LED. This voltage drop directly reflects the change in LED junction temperature. Therefore, by acquiring the forward voltage across the LED, the actual junction temperature of the LED can be calculated.

[0085] The analog-to-digital converter samples the forward voltage drop and converts it into a digital signal. The digital signal is then transmitted to the microcontroller via high-speed sampling for temperature calculation.

[0086] To obtain high-precision temperature measurements, the sampling speed and accuracy of the analog-to-digital converter (ADC) are crucial. The sampling frequency needs to be high enough to ensure accurate capture and real-time processing of voltage changes during LED operation.

[0087] An analog-to-digital converter converts an analog voltage signal into a digital signal, enabling a microcontroller to accurately read the forward voltage drop across the LED and then calculate the real-time junction temperature using the voltage-temperature relationship.

[0088] Combining the above modules, the overall workflow of the junction temperature monitoring module is as follows: A constant current source provides a constant current: A small and constant measuring current flows through the LED, generating a positive voltage. An analog switch switches the current path: The analog switch, controlled by the microcontroller, switches between normal LED operation and the measurement phase, ensuring the constant current source's measuring current flows through the LED. An analog-to-digital converter samples the voltage: During the measurement phase, the analog-to-digital converter quickly samples the positive voltage across the LED and converts it into a digital signal. The microcontroller processes the data: After receiving the digital signal, the microcontroller calculates the LED's real-time junction temperature based on a pre-stored voltage-temperature lookup table or fitting formula.

[0089] According to another aspect of this application, a computer-readable storage medium storing a computer program is provided, wherein when the computer program is executed by a processor, it implements the steps of any of the methods described above; the computer-readable storage medium includes, but is not limited to, a read-only memory, a random access memory, flash memory, a hard disk, or a solid-state drive.

[0090] Furthermore, a computer-readable storage medium refers to a physical medium capable of storing computer programs and being read by a computer or microcontroller. The program instructions stored in this storage medium can guide the system to perform adaptive speed-regulating heat dissipation tasks for LED lamps during execution. Common computer-readable storage media include, but are not limited to: Read-only memory (ROM): A type of storage medium used to permanently store program instructions, typically loaded and executed during system startup. Data in ROM does not change during normal use.

[0091] Random Access Memory (RAM): A storage medium for temporarily storing data and program instructions. Data stored in RAM can be read and written quickly, but it is lost when the power is turned off.

[0092] Flash memory: a non-volatile storage medium that retains data even after power is lost. It is commonly used to store program code and real-time data.

[0093] Hard disk drives (HDDs) and solid-state drives (SSDs): These two storage media are used for large-capacity data storage, and are especially common in applications that require large storage space or high-frequency data access.

[0094] These storage media collectively provide the system with a program execution platform, enabling the system to perform various complex computing tasks in real time, such as LED driver instruction monitoring, junction temperature measurement, and fan control.

[0095] The program instructions stored in a computer-readable storage medium contain steps for implementing an adaptive speed-regulating heat dissipation method for LED luminaires. Specifically, these program instructions include, but are not limited to, the following: Drive command signal acquisition: The program command control drive command monitoring module acquires the LED drive signal (PWM signal or analog level signal) in real time and transmits the signal to the microcontroller for analysis.

[0096] Junction temperature monitoring and control: The program commands acquire the junction temperature data of the LED through the junction temperature monitoring module and process it in real time. Combining feedforward and feedback control strategies, the program generates control variables based on the deviation between the junction temperature and the target junction temperature.

[0097] Feedforward and feedback fan control: The program controls the fan adjustment module to adjust the fan speed based on changes in drive commands and real-time junction temperature data, combined with feedforward and feedback algorithms.

[0098] Fan PWM control signal generation: The program generates the final fan PWM control signal and outputs it to the fan drive module to adjust the fan speed to ensure that the LED is within a suitable operating temperature range.

[0099] Dynamic thermal inertia model optimization: The program periodically compares the difference between the predicted junction temperature and the actual junction temperature, and adjusts the parameters of the dynamic thermal inertia mapping model based on the recursive least squares method or gradient descent method to improve prediction accuracy.

[0100] The design and execution of these program instructions ensure that the system can achieve automatic and precise LED heat dissipation control under different operating conditions, thereby optimizing temperature control and extending LED lifespan.

[0101] When a program in a computer-readable storage medium is loaded and executed by a microcontroller or processor, the processor will perform operations on various functional modules according to the program instructions, and perform necessary calculations and decisions. For example, the microcontroller will execute a fan control algorithm based on real-time acquired drive instruction signals and junction temperature data to generate a suitable PWM signal to control the fan speed. Simultaneously, the processor will periodically optimize the thermal inertia model to ensure accurate prediction of the LED junction temperature.

[0102] Through the execution of a computer program, LED lighting fixtures can achieve adaptive speed-controlled heat dissipation. The program processes real-time data and dynamically adjusts the fan speed based on changes in LED load and junction temperature, ensuring that the LED's operating temperature remains within a reasonable range. This not only improves heat dissipation efficiency but also effectively extends the lifespan of the LED lighting fixtures.

[0103] Therefore, the adaptive speed regulation and heat dissipation method for LED lamps based on real-time junction temperature monitoring in this application processes the drive command signal and real-time junction temperature information in parallel, and integrates the advance feedforward control quantity based on command prediction and the precise feedback control quantity based on junction temperature monitoring in real time, thereby generating a composite fan control signal that can synchronously respond to changes in heat load and effectively suppress system lag, and finally achieves adaptive and precise regulation of the cooling fan speed.

[0104] The embodiments described above are merely examples of several implementations of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the scope of protection of this application.

Claims

1. A method for adaptive speed regulation and heat dissipation of LED lamps based on real-time junction temperature monitoring, characterized in that, Includes the following steps: S100 acquires the LED driving command signal in real time. The driving command signal is a PWM signal or an analog level signal used to control the LED brightness or current. Based on the changes in the drive command signal, S200 uses the dynamic thermal inertia mapping model stored in the pre-stored memory to perform feedforward prediction and generate the corresponding feedforward fan control quantity. S300 monitors the junction temperature of the LED in real time using the forward voltage method, and generates a feedback fan control quantity through the feedback controller based on the deviation between the monitored real-time junction temperature and the preset target junction temperature. S400 combines the feedforward fan control signal and the feedback fan control signal to generate the final fan PWM control signal, and outputs it to the fan drive circuit to drive the cooling fan to adjust the speed and dissipate heat from the LED.

2. The adaptive speed regulation and heat dissipation method for LED lamps based on real-time junction temperature monitoring according to claim 1, characterized in that, In step S200, the "based on the change of the driving command signal" specifically means: calculating the change of the instantaneous value of the driving command signal relative to the value at the previous moment in real time; when the absolute value of the change exceeds a preset amplitude threshold, and / or the rate of change per unit time exceeds a preset rate threshold, the feedforward prediction is triggered.

3. The adaptive speed regulation and heat dissipation method for LED lamps based on real-time junction temperature monitoring according to claim 1, characterized in that, The dynamic thermal inertia mapping model is a linear or nonlinear mathematical model that describes the mapping relationship between the change in driving command and the expected change in junction temperature. The model includes at least two key parameters: thermal capacity gain and thermal time constant. The thermal capacity gain characterizes the steady-state change in junction temperature caused by a unit change in driving command, and the thermal time constant characterizes the response speed of the junction temperature change.

4. The adaptive speed regulation and heat dissipation method for LED lamps based on real-time junction temperature monitoring according to claim 1, characterized in that, The "real-time monitoring via forward voltage method" mentioned in step S300 specifically includes: During the preset off-time of the LED pulse drive current, the drive current is switched to a constant, microamp-level measurement current via an analog switch. The forward voltage drop across the LED is quickly sampled using an analog-to-digital converter. The current real-time junction temperature is calculated based on a pre-stored voltage-temperature lookup table or fitting formula obtained through calibration.

5. The adaptive speed regulation and heat dissipation method for LED lamps based on real-time junction temperature monitoring according to claim 1, characterized in that, In step S300, the feedback controller is a proportional-integral-derivative controller, which calculates the feedback fan control quantity based on the deviation between the real-time junction temperature and the target junction temperature through a combination of proportional, integral, and derivative operations.

6. The adaptive speed regulation and heat dissipation method for LED lamps based on real-time junction temperature monitoring according to claim 1, characterized in that, In step S4, the "synthesis" is to linearly superimpose the feedforward fan control quantity and the feedback fan control quantity in an algebraic manner, and limit the superposition result to a preset PWM duty cycle output range.

7. The adaptive speed regulation and heat dissipation method for LED lamps based on real-time junction temperature monitoring according to claim 1, characterized in that, The method further includes step S500: The junction temperature change curve predicted by the dynamic thermal inertia mapping model is periodically compared with the junction temperature change curve actually monitored by the forward voltage method. Based on the residual between the two, the parameters of the dynamic thermal inertia mapping model are fine-tuned and optimized online using the recursive least squares method or the gradient descent method.

8. An adaptive speed-regulating heat dissipation system for LED lamps to implement the method as described in any one of claims 1-7, characterized in that, include: Microcontrollers serve as the core computing and control unit of the system; The drive command monitoring module is connected to the input port of the microcontroller and the LED driver circuit, and is used to acquire the drive command signal in real time. A junction temperature monitoring module, connected to the microcontroller and LED chip, is used to measure the junction temperature using the forward voltage method. A fan drive module is connected to the PWM output port of the microcontroller and is used to receive the final fan PWM control signal and drive the cooling fan. The microcontroller is configured to execute program instructions stored therein to perform the method steps as described in any one of claims 1 to 7.

9. The adaptive speed regulation and heat dissipation method for LED lamps based on real-time junction temperature monitoring according to claim 8, characterized in that, The junction temperature monitoring module includes: A constant current source is used to provide the constant measurement current; An analog switch, controlled by the microcontroller, is used for high-speed switching between the normal drive current path and the constant current source measurement path; An analog-to-digital converter is used to sample the forward voltage across the LED during the measurement phase and convert it into a digital signal for the microcontroller to read.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method as described in any one of claims 1-7; the computer-readable storage medium includes, but is not limited to, read-only memory, random access memory, flash memory, hard disk, or solid-state drive.

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