Process control system and method for LED luminaire manufacturing

Abstract

This invention relates to the field of process control technology, and discloses a process control system and method for LED lamp manufacturing. The method includes: collecting high-temperature stress response parameters after aging the LED lamp in a high-temperature stress zone; sequentially applying high-voltage stress and low-voltage stress to the LED lamp and collecting voltage stress response parameters; applying switching impact stress to the LED lamp and collecting spectral characteristic parameters; collecting the steady-state temperature and junction temperature compensation coefficient of the LED lamp, and constructing steady-state photoelectric parameters based on the steady-state temperature and junction temperature compensation coefficient; calculating a comprehensive quality index based on the steady-state photoelectric parameters, high-temperature stress response parameters, voltage stress response parameters, and spectral characteristic parameters, and determining the quality grade of the LED lamp based on the comprehensive quality index. This invention achieves 100% product inspection, solving the problem of high missed inspection rates in traditional sampling methods, and realizing intelligent quality control in the LED lamp manufacturing process.

Description

Technical Field

[0001] This invention relates to the field of manufacturing process control technology, and in particular to a process control system and method for manufacturing LED lamps. Background Technology

[0002] As mainstream lighting products, the quality control of LED lighting fixtures directly affects product reliability and market competitiveness. Traditional LED lighting fixture manufacturing processes use batch sampling inspection for quality control, with a sampling rate of only 5-10%. This results in a large number of defective products with abnormal light decay, color temperature drift, and substandard color rendering index not being detected in a timely manner, leading to a high rate of missed inspections.

[0003] Existing aging test methods employ a single stress loading approach, such as high-temperature aging or high-pressure aging alone. These methods fail to simulate the complex stress environments faced by LED lighting fixtures in actual use, including grid fluctuations, temperature cycling, and frequent switching. Consequently, they struggle to effectively induce early failure modes, leading to rapid light decay and color drift in actual use. Furthermore, LED photoelectric parameters are highly sensitive to junction temperature. Current production lines employ transient measurement methods to improve testing efficiency, performing optical measurements before the LED reaches thermal equilibrium. This results in significant measurement errors, severely impacting the accuracy of quality grading. Summary of the Invention

[0004] The main objective of this invention is to provide a process control system and method for LED lighting fixture manufacturing. This invention achieves 100% product inspection, solves the problem of high missed inspection rate in traditional sampling inspection methods, and realizes intelligent quality control in the LED lighting fixture manufacturing process.

[0005] To achieve the above objectives, the present invention provides a process control method for LED lamp manufacturing, comprising the following steps: After aging the LED lamps in a high-temperature stress zone, high-temperature stress response parameters were collected; high-voltage stress and low-voltage stress were sequentially applied to the LED lamps, and voltage stress response parameters were collected; switching impact stress was applied to the LED lamps, and spectral characteristic parameters were collected. The steady-state temperature and junction temperature compensation coefficient of the LED lamp are collected, and steady-state photoelectric parameters are constructed based on the steady-state temperature and the junction temperature compensation coefficient. The comprehensive quality index is calculated based on the steady-state photoelectric parameters, the high-temperature stress response parameters, the voltage stress response parameters, and the spectral characteristic parameters, and the quality grade of the LED lamp is determined based on the comprehensive quality index.

[0006] Optionally, in a first implementation of the first aspect of the present invention, the high-temperature stress response parameters are collected after the LED lamp is aged in a high-temperature stress zone; high voltage stress and low voltage stress are sequentially applied to the LED lamp and voltage stress response parameters are collected; switching impact stress is applied to the LED lamp and spectral characteristic parameters are collected, including: Before the LED lamp is mounted on the conductive rail, initial full-spectrum data at room temperature is collected by an integrating sphere to calculate the initial luminous flux and initial color temperature, and the initial luminous flux and initial color temperature are used as optical reference values. The LED lamp is aged in a high-temperature stress zone. At the exit of the high-temperature stress zone, the first stress full spectrum data is collected and the first stress luminous flux and stress color temperature are calculated. Based on the optical reference value, the first luminous flux change rate and color temperature shift are calculated. The first luminous flux change rate and the color temperature shift are used as high-temperature stress response parameters. A second stress full-spectrum data is collected by applying high voltage stress to the LED lamp, and then a third stress full-spectrum data is collected by applying low voltage stress to the LED lamp. The voltage stress response parameters are calculated based on the second stress full-spectrum data and the third stress full-spectrum data. A switching impact stress is applied to the LED lamp and the fourth stress full spectrum data is collected. Spectral characteristic parameters are calculated based on the fourth stress full spectrum data.

[0007] Optionally, in a second implementation of the first aspect of the present invention, high voltage stress is applied to the LED lamp to collect second stress full-spectrum data, then low voltage stress is applied to the LED lamp to collect third stress full-spectrum data, and voltage stress response parameters are calculated based on the second stress full-spectrum data and the third stress full-spectrum data, including: The LED lamp is subjected to high voltage stress in a high voltage stress zone. Second stress full spectrum data is collected at the exit of the high voltage stress zone and the second stress luminous flux is calculated. The second luminous flux change rate is calculated based on the first stress luminous flux and the second stress luminous flux. The LED lamp is subjected to low voltage stress in a low voltage stress zone. At the exit of the low voltage stress zone, the full spectrum data of the third stress is collected and the luminous flux of the third stress is calculated. The rate of change of the third luminous flux is calculated based on the luminous flux of the second stress and the luminous flux of the third stress. The voltage stress response asymmetry is calculated based on the second luminous flux change rate and the third luminous flux change rate, and the voltage stress response asymmetry is used as the voltage stress response parameter.

[0008] Optionally, in a third implementation of the first aspect of the present invention, applying a switching impact stress to the LED lamp and acquiring fourth stress full-spectrum data, and calculating spectral characteristic parameters based on the fourth stress full-spectrum data, includes: The LED lamp is passed through the switch impact stress zone. At the exit of the switch impact stress zone, the full spectrum data of the fourth stress is collected and the luminous flux of the fourth stress is calculated. Based on the luminous flux of the third stress and the luminous flux of the fourth stress, the rate of change of the fourth luminous flux is calculated. Based on the first luminous flux change rate, the second luminous flux change rate, the third luminous flux change rate, and the fourth luminous flux change rate, the luminous flux attenuation acceleration and attenuation non-uniformity are calculated, and the luminous flux attenuation acceleration and attenuation non-uniformity are used as spectral characteristic parameters.

[0009] Optionally, in a fourth implementation of the first aspect of the present invention, the luminous flux attenuation acceleration and attenuation non-uniformity are calculated based on the first luminous flux change rate, the second luminous flux change rate, the third luminous flux change rate, and the fourth luminous flux change rate, and the luminous flux attenuation acceleration and attenuation non-uniformity are used as spectral characteristic parameters, including: Calculate the difference between the fourth rate of change of luminous flux and the first rate of change of luminous flux, and calculate the luminous flux attenuation acceleration based on the difference in the rate of change; Calculate the standard deviation and mean of the first luminous flux change rate, the second luminous flux change rate, the third luminous flux change rate, and the fourth luminous flux change rate; Dividing the standard deviation by the mean yields the attenuation non-uniformity. The luminous flux attenuation acceleration and the attenuation non-uniformity are combined as spectral characteristic parameters.

[0010] Optionally, in a fifth implementation of the first aspect of the present invention, the steady-state temperature and junction temperature compensation coefficient of the LED lamp are collected, and steady-state photoelectric parameters are constructed based on the steady-state temperature and the junction temperature compensation coefficient, including: The resistance of the LED lamp substrate is collected and converted into the substrate temperature. The temperature change rate of adjacent sampling points is calculated. When the temperature change rate is less than a preset threshold and the temperature is lower than a set value, the LED lamp is determined to be in a steady state and the steady state temperature is obtained. The steady-state junction temperature is calculated based on the steady-state temperature, ambient temperature, LED thermal resistance, and power dissipation. The junction temperature compensation coefficient is calculated based on the steady-state junction temperature and the reference junction temperature. Based on the steady-state temperature, the luminous flux, target color temperature, color rendering index, dominant wavelength, and color coordinate deviation are calculated and corrected using the junction temperature compensation coefficient to obtain the steady-state photoelectric parameters.

[0011] Optionally, in a sixth implementation of the first aspect of the present invention, the steady-state photoelectric parameters are obtained by calculating the luminous flux, target color temperature, color rendering index, dominant wavelength, and color coordinate deviation based on the steady-state temperature and correcting them in conjunction with the junction temperature compensation coefficient, including: After the LED lamp is in a steady state, steady-state full-spectrum data is collected by the spectrometer built into the integrating sphere, and spectral irradiance data is generated based on the steady-state full-spectrum data. The luminous flux, target color temperature, color rendering index, dominant wavelength, and color coordinate deviation are calculated based on the spectral irradiance data. The luminous flux and the target color temperature are corrected according to the junction temperature compensation coefficient to obtain the corrected luminous flux. The corrected luminous flux, target color temperature, color rendering index, dominant wavelength and color coordinate deviation are combined as steady-state photoelectric parameters.

[0012] Optionally, in a seventh implementation of the first aspect of the present invention, calculating the luminous flux, target color temperature, color rendering index, dominant wavelength, and color coordinate deviation based on the spectral irradiance data includes: The luminous flux is obtained by multiplying each wavelength point in the spectral irradiance data by the visual spectral luminous efficiency function, summing the results, and then multiplying by a constant. The three chromaticity components are obtained by multiplying each wavelength point in the spectral irradiance data with the standard chromaticity observer function and summing the results. The chromaticity coordinates are then calculated based on the three chromaticity components. The target color temperature is calculated based on the color coordinates, the wavelength corresponding to the maximum value in the spectral irradiance data is taken as the main wavelength, and the color coordinate deviation between the color coordinates and the nominal color coordinates is calculated. The color difference of each color sample under LED lighting is calculated based on the spectral irradiance data and the reflectance spectrum of the standard color sample, and the color rendering index is calculated based on the color difference of multiple color samples.

[0013] Optionally, in an eighth implementation of the first aspect of the present invention, calculating a comprehensive quality index based on the steady-state photoelectric parameters, the high-temperature stress response parameters, the voltage stress response parameters, and the spectral characteristic parameters, and determining the quality grade of the LED luminaire based on the comprehensive quality index, includes: Calculate the optical performance evaluation index based on the steady-state photoelectric parameters; The reliability prediction index is calculated based on the high-temperature stress response parameters, the voltage stress response parameters, and the spectral characteristic parameters. The comprehensive quality index is calculated based on the optical performance evaluation index and the reliability prediction index. When the comprehensive quality index is greater than the first threshold and the deviation of all individual parameters is less than the first deviation limit, the quality grade of the LED lamp is determined to be Grade A. When the comprehensive quality index is between the first threshold and the second threshold, the quality grade of the LED lamp is determined to be Grade B. When the comprehensive quality index is less than the second threshold or the deviation of any individual parameter is greater than the second deviation limit, the quality grade of the LED lamp is determined to be unqualified.

[0014] The present invention also provides a process control system for LED lamp manufacturing, comprising: The acquisition module is used to acquire high-temperature stress response parameters after the LED lamp has been aged in a high-temperature stress zone; to apply high voltage stress and low voltage stress to the LED lamp sequentially and acquire voltage stress response parameters; and to apply switching impact stress to the LED lamp and acquire spectral characteristic parameters. A construction module is used to collect the steady-state temperature and junction temperature compensation coefficient of the LED lamp, and to construct steady-state photoelectric parameters based on the steady-state temperature and the junction temperature compensation coefficient; The grading module is used to calculate a comprehensive quality index based on the steady-state photoelectric parameters, the high-temperature stress response parameters, the voltage stress response parameters, and the spectral characteristic parameters, and to determine the quality grade of the LED lamps based on the comprehensive quality index.

[0015] In summary, this invention employs four sequential stress loading methods—high temperature, high and low voltage, and switching impact—to simulate the complex stress environment of LEDs in actual use within a short time. This effectively excites early failure modes such as PN junction breakdown, phosphor layer cracking, and wire fatigue. By acquiring spectral data in real time at the stress stage exit and calculating the rate of change of luminous flux, evolutionary characteristic parameters such as attenuation acceleration and attenuation non-uniformity are extracted, enabling quantitative prediction of the long-term optical stability of LEDs. Real-time monitoring of the substrate temperature using an NTC thermistor and determination of the thermal steady-state conditions, combined with a junction temperature compensation factor, corrects for luminous flux and color temperature, eliminating systematic errors introduced by transient measurements and improving the accuracy and consistency of photoelectric parameter measurements. This invention establishes a dual-dimensional comprehensive quality evaluation system combining optical performance evaluation index and reliability prediction index. It considers not only the current optical performance indicators of LEDs, such as luminous flux, color temperature, and color rendering index, but also predicts the reliability of LEDs in long-term use through stress response parameters and spectral evolution characteristics, avoiding the omission of potential failure risks due to relying solely on current performance. This invention achieves 100% product inspection, solving the problem of high missed inspection rate in traditional sampling methods, and realizing intelligent quality control in the LED lighting manufacturing process. Attached Figure Description

[0016] Figure 1This is a schematic diagram of the process control method for LED lamp manufacturing in one embodiment of the present invention; Figure 2 This is a block diagram of the process control system for LED lamp manufacturing in an embodiment of the present invention.

[0017] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0019] Reference Figure 1 This embodiment provides a process control method for LED lamp manufacturing, including the following steps: S1. After aging the LED lamp in a high-temperature stress zone, collect the high-temperature stress response parameters; apply high voltage stress and low voltage stress to the LED lamp sequentially and collect the voltage stress response parameters; apply switching impact stress to the LED lamp and collect the spectral characteristic parameters. S2, collect the steady-state temperature and junction temperature compensation coefficient of the LED lamp, and construct steady-state photoelectric parameters based on the steady-state temperature and junction temperature compensation coefficient; S3 calculates the comprehensive quality index based on steady-state photoelectric parameters, high-temperature stress response parameters, voltage stress response parameters, and spectral characteristic parameters, and determines the quality level of LED lamps based on the comprehensive quality index.

[0020] In one example, high-temperature stress response parameters are collected after aging the LED lamp in a high-temperature stress zone; high-voltage stress and low-voltage stress are applied to the LED lamp sequentially, and voltage stress response parameters are collected; switching impact stress is applied to the LED lamp, and spectral characteristic parameters are collected, including: Before the LED lamps are mounted on the conductive rails, initial full-spectrum data at room temperature are collected by an integrating sphere to calculate the initial luminous flux and initial color temperature, and the initial luminous flux and initial color temperature are used as optical reference values. The LED lamps are aged in a high-temperature stress zone. The full spectrum data of the first stress is collected at the exit of the high-temperature stress zone, and the first stress luminous flux and stress color temperature are calculated. The first luminous flux change rate and color temperature shift are calculated based on the optical reference value. The first luminous flux change rate and color temperature shift are used as high-temperature stress response parameters. High voltage stress is applied to the LED lamp to collect second stress full spectrum data, then low voltage stress is applied to the LED lamp to collect third stress full spectrum data, and voltage stress response parameters are calculated based on the second stress full spectrum data and the third stress full spectrum data; A switching impact stress is applied to the LED lamp and the full spectrum data of the fourth stress is collected. The spectral characteristic parameters are calculated based on the full spectrum data of the fourth stress.

[0021] In this example, a room-temperature optical acquisition station is set up in the entrance area before the LED luminaire enters the conveyor rail. The station is equipped with a small integrating sphere and a miniature spectrometer. The integrating sphere has an 80mm aperture, and the spectrometer's wavelength range covers 380nm to 780nm, with an integration time set to approximately 30ms. At this station, after applying the rated voltage to the LED, its initial emission spectrum S0(λ) is acquired. The luminous flux Φ0 is calculated using the CIE standard luminous function and integral formula. Simultaneously, the color coordinates u′0 and v′0 are calculated based on the tristimulus values ​​X0, Y0, and Z0, and then converted to the initial color temperature CCT0 using the McCamy formula. These two values ​​are used as the optical reference values ​​for the luminaire and written into the RFID tag. The LED lamp is loaded onto the guide rail and advanced at a constant speed to the high-temperature stress zone. In this zone, the LED substrate is heated to 150±3℃ by the bottom ceramic heating plate and maintained for 20 seconds for aging. The first stress spectrum S1(λ) is then collected at the zone exit, and the luminous flux Φ1 and color temperature CCT1 under high temperature conditions are calculated in real time. The rate of change of luminous flux η under high-temperature stress is then calculated based on the ratio of these values ​​to the initial values ​​Φ0 and CCT0. T = (Φ1 - Φ0) / Φ0 and color temperature offset ΔCCT T = CCT1 - CCT0, used to measure the light output capability and color temperature stability of an LED under thermal load, respectively. Continuing into the high-voltage stress region, the input voltage is increased to 1.25 times the rated value using a thyristor voltage regulation module. After continuously applying the high voltage for 16.7 seconds, the second stress spectrum S2(λ) is collected, and the corresponding luminous flux Φ2 is calculated. Then, in the low-voltage stress region, the input voltage is reduced to 0.75 times the rated value, and after again continuously applying the high voltage for 16.7 seconds, the third stress spectrum S3(λ) is collected, and the luminous flux Φ3 is calculated. Based on this, the rate of change of luminous flux η during the voltage boosting stage is calculated. VH = (Φ2 - Φ1) / Φ1 and the rate of change η during the pressure reduction phase VL = (Φ3 - Φ2) / Φ2, extract the electro-optic response law of LED under voltage upper and lower limit fluctuations, and combine it with the response symmetry coefficient γ V = |η VH | / |η VL| To determine the driver's regulation performance and the linearity of the PN junction response. After the voltage stress stage, the LED luminaire enters the switching impact stress zone. In this zone, a high-frequency power on / off cycle of 300 times / minute is implemented through a relay array, superimposed with ±15% voltage fluctuation, simulating the complex electrical stress excitation environment such as frequent switching and voltage transients in actual operation. After 13.3 seconds, the fourth stress spectrum S4(λ) is collected at the end of the zone, and the luminous flux Φ4, color temperature CCT4, and flux change rate η are calculated. SW = (Φ4 - Φ3) / Φ3, and simultaneously extract the optical decay acceleration a by combining the optical flux sequence from Φ0 to Φ4. 衰 = (η SW - η T ) / 3 and attenuation non-uniformity σ 衰 Evolutionary characteristic indicators, etc.

[0022] In one example, high voltage stress is applied to the LED luminaire to collect second-stress full-spectrum data, then low voltage stress is applied to the LED luminaire to collect third-stress full-spectrum data, and voltage stress response parameters are calculated based on the second and third-stress full-spectrum data, including: The LED lamp is subjected to high voltage stress in a high voltage stress zone. The full spectrum data of the second stress is collected at the exit of the high voltage stress zone and the luminous flux of the second stress is calculated. The rate of change of the second luminous flux is calculated based on the luminous flux of the first stress and the luminous flux of the second stress. The LED lamp is subjected to low voltage stress in the low voltage stress zone. The full spectrum data of the third stress is collected at the exit of the low voltage stress zone and the luminous flux of the third stress is calculated. The rate of change of the third luminous flux is calculated based on the luminous flux of the second stress and the luminous flux of the third stress. The voltage stress response asymmetry is calculated based on the second and third luminous flux change rates, and is used as a voltage stress response parameter.

[0023] In this example, a voltage response feature extraction pathway is established based on the sequential application of high and low voltage aging processes, using continuous spectral sampling and parameter ratio analysis. After the LED lamp passes through the high-temperature stress zone, its luminous flux drops to Φ1, and it enters the high-voltage stress zone. In the high-voltage stress zone, the input voltage is increased to 1.25 times the rated voltage via a thyristor voltage regulation module. Under this sustained voltage stress, the PN junction current density of the LED chip increases, accompanied by possible quantum well carrier overflow and intensified solder joint heating, thus significantly affecting the light output. After the LED reaches the exit of the high-voltage stress zone, the second stress full spectrum S2(λ) is collected using a fiber optic spectrometer, and the luminous flux Φ2 under high voltage is calculated according to the standard visible spectrum weighted formula. Using Φ2 and Φ1 as a reference, the rate of change of the second luminous flux is defined as η. VH= (Φ2 - Φ1) / Φ1, to reflect the trend of light output change of LED under overvoltage excitation conditions. Next, the LED luminaire enters the low-voltage stress region, where the voltage drops to 0.75 times the rated value, simulating undervoltage driving conditions in actual applications. Within this region, the LED current decreases significantly, and some drivers exhibit voltage regulation imbalance. The third stress spectrum S3(λ) is collected at the exit of the low-voltage region, the corresponding luminous flux Φ3 is calculated, and the rate of change of the third luminous flux η is determined. VL = (Φ3 - Φ2) / Φ2, quantifying the output decline after low-voltage action. This is achieved by adjusting η... VH With η VL The voltage stress response asymmetry γ is calculated by performing a ratio operation on the modulus values. V = |η VH | / |η VL | represents the symmetry of the LED response under high and low pressure, with an ideal value of approximately 1.0, such as γ. V A value > 1.5 indicates that the high-voltage response is stronger than the low-voltage suppression, suggesting either falsely advertised power or current-limiting circuit misalignment; for example, γ V A value < 0.6 indicates excessive attenuation of the low-voltage response, suggesting insufficient undervoltage stability of the driver or weak chip conduction characteristics. (The last part, "γ," appears to be an error and doesn't translate directly.) V As an indicator characterizing the nonlinear response of LED lighting fixtures to photoelectric performance under electrical stress, it is written into RFID tags.

[0024] The voltage stress response asymmetry is calculated based on the second and third luminous flux change rates, and used as a voltage stress response parameter. The process also includes: determining the anomaly type of the voltage stress response asymmetry; when the asymmetry is less than 0.6, it is classified as a driving circuit undervoltage failure anomaly; when it is greater than 1.5, it is classified as a PN junction nonlinear aging anomaly; and when it is between 0.6 and 1.5, it is classified as a normal response type. The stress parameters of the subsequent switching impact stress zone are adjusted according to the anomaly type. For LED lamps classified as driving circuit undervoltage failure anomalies, the switching impact frequency is reduced from 300 times per minute to 180 times per minute, and the voltage pulse fluctuation amplitude is reduced from ±15% to ±10%. For lamps classified as PN junction nonlinear aging anomalies... The switching impact frequency of LED luminaires was kept constant, but the duration was extended from 13.3 seconds to 20 seconds. For LED luminaires judged to be of normal response type, the switching impact stress was applied according to standard parameters. The changes in the fourth stress luminous flux and the third stress luminous flux collected at the exit of the switching impact stress zone of LED luminaires with different stress parameters were recorded. The difference in the rate of change of the fourth luminous flux before and after adaptive adjustment was calculated. When the absolute value of the difference was greater than 0.02, the stress adaptive adjustment was confirmed to be effective. When calculating the reliability prediction index, a voltage stress penalty weight of 0.15 was added to LED luminaires with insufficient withstand voltage of the drive circuit, a thermal stress penalty weight of 0.10 was added to LED luminaires with nonlinear aging of the PN junction, and the standard penalty weight was maintained for LED luminaires of normal response type, so as to realize differentiated reliability evaluation based on the anomaly type.

[0025] In one example, a switching impact stress is applied to an LED lamp, and fourth-stress full-spectrum data is collected. Spectral characteristic parameters are calculated based on the fourth-stress full-spectrum data, including: The LED lamp is passed through the switch impact stress zone. The full spectrum data of the fourth stress is collected at the exit of the switch impact stress zone and the luminous flux of the fourth stress is calculated. The rate of change of the fourth luminous flux is calculated based on the luminous flux of the third stress and the luminous flux of the fourth stress. Based on the first, second, third, and fourth rates of change of luminous flux, the luminous flux attenuation acceleration and attenuation non-uniformity are calculated, and these are used as spectral characteristic parameters.

[0026] In this example, after undergoing high and low voltage stress, the luminous flux of the LED lamp has dropped to the third-stage value Φ3. It then enters the switching impact stress zone, where a relay array periodically switches the power supply on and off 300 times per minute, with a ±15% fluctuation superimposed on the voltage input to simulate the complex operating conditions encountered in actual product operation, such as cold start, high-frequency start-stop, and voltage transients. This stage lasts 13.3 seconds and completes 67 effective switching cycles, inducing frequent jumps in the LED chip junction temperature, thermal fatigue cracking of the phosphor coating, and accumulation of thermomechanical stress at the bonding wire connection points within a limited time. When the LED lamp reaches the exit position of the switching impact stress zone, the fourth stress spectral data S4(λ) is collected by the fiber optic spectral sampling unit deployed on the sidewall of the guide rail, and the corresponding luminous flux Φ4 is calculated in real time. Using the luminous flux Φ3 at the end of the third stage as a reference, the fourth luminous flux change rate η4 = (Φ4 - Φ3) / Φ3 is calculated, reflecting the amplitude of the light output disturbance caused by the switching impact stress. Combining the three luminous flux change rates under preceding stress, namely η1 = (Φ1 - Φ0) / Φ0, η2 = (Φ2 - Φ1) / Φ1, and η3 = (Φ3 - Φ2) / Φ2, a luminous flux response sequence {η1, η2, η3, η4} is constructed. The luminous flux attenuation acceleration α is defined as the difference between η4 and η1 divided by the number of three-stage intervals. 衰 = (η4 - η1) / 3, reflecting the accelerated light decay trend of LED lamps under continuous multi-stress aging. If a 衰 If a value is positive and significantly deviates from zero, it indicates that the LED has an accelerated aging rate; while if a... 衰 If the value is approximately zero, it can be considered that the optical output stability is good. The attenuation non-uniformity σ is obtained by calculating the ratio of the standard deviation std(η1, η2, η3, η4) between η1 and η4 to their mean modulus (|η1|, |η2|, |η3|, |η4|). 衰 This is used to characterize the consistency and stability of LED response under various stresses. If σ 衰 A high value indicates that the light decay behavior of the LED fluctuates greatly under different aging conditions, suggesting potential stability issues such as structural defects or uneven heat dissipation. The luminous flux decay acceleration and decay non-uniformity are stored as spectral characteristic parameters in the RFID tag of the LED lamp.

[0027] In one example, based on the first, second, third, and fourth rates of change of luminous flux, the luminous flux attenuation acceleration and attenuation non-uniformity are calculated, and these are used as spectral characteristic parameters, including: Calculate the difference between the fourth rate of change of luminous flux and the first rate of change of luminous flux, and calculate the luminous flux attenuation acceleration based on the difference in rates of change; Calculate the standard deviation and mean of the first, second, third, and fourth luminous flux change rates; Dividing the standard deviation by the mean yields the attenuation non-uniformity. The combination of luminous flux attenuation acceleration and attenuation non-uniformity is used as a spectral characteristic parameter.

[0028] In this example, as the LED lamp sequentially passes through the high-temperature stress zone, high-voltage stress zone, low-voltage stress zone, and switching impact stress zone, full-spectrum data is simultaneously collected at the exit of each stress zone, and the luminous flux Φ1, Φ2, Φ3, and Φ4 of the four stages are calculated. These are then compared with the initial luminous flux Φ0 and the luminous flux of the previous stage to obtain four luminous flux change rates, denoted as η1 = (Φ1 - Φ0) / Φ0, η2 = (Φ2 - Φ1) / Φ1, η3 = (Φ3 - Φ2) / Φ2, and η4 = (Φ4 - Φ3) / Φ3. When constructing the luminous flux attenuation acceleration, the direct difference between η4 and η1 is calculated and then divided by the number of stages between them, i.e., a. 衰 = (η4 - η1) / 3, yielding the accelerating trend of luminous flux change rate with stress sequence development. This index is used to reveal whether the LED aging rate accelerates with stress accumulation. If a 衰 If the value is positive and exceeds a set threshold, it indicates that the device is at risk of accelerated degradation. A complete sample set is formed from the four rates of change η1, η2, η3, and η4, and the standard deviation σ is calculated based on this sample set. η = √[Σ(η i - η 均 ) 2 / 4], where η 均 The mean rate of change η 均 = (η1 + η2 + η3 + η4) / 4, and then pass σ η ÷ η 均 Calculate the attenuation non-uniformity σ 衰 This parameter is used to reflect the dispersion or fluctuation range of luminous flux response. A higher attenuation non-uniformity value indicates that the behavior of the LED is more inconsistent after being stressed at different stages, reflecting problems such as uneven thermal conduction paths of chip solder joints, abnormal distribution of fluorescent coating, or differences in the stability of driving circuits. The luminous flux attenuation acceleration and attenuation non-uniformity are combined to form a set of spectral characteristic parameters, which are then written into the RFID tag or test database of the corresponding LED lamp.

[0029] The calculation of the difference between the fourth and first luminous flux change rates, and the calculation of the luminous flux attenuation acceleration based on the difference, also includes: calculating the deviations of the first, second, and fourth luminous flux change rates from their initial values, respectively, to obtain a sequence of rate deviations between the four stages; calculating the ratio of the maximum deviation to the average deviation in the sequence; determining a sudden spectral evolution trajectory failure risk when the ratio is greater than a first anomaly threshold; determining an accelerated spectral evolution trajectory failure risk when the luminous flux attenuation acceleration is greater than a second anomaly threshold and the attenuation non-uniformity is less than a uniformity threshold; marking LED luminaires identified as having a sudden failure risk as high-risk and removing them from the non-conforming product list; marking LED luminaires identified as having an accelerated failure risk as medium-risk and triggering a secondary aging verification process; and marking LED luminaires that did not trigger a failure risk assessment as low-risk and entering the normal testing process.

[0030] The calculation of the difference between the fourth and first luminous flux change rates, and the calculation of luminous flux attenuation acceleration based on the difference, also includes: constructing a change rate sequence based on the stress stage number of the first, second, third, and fourth luminous flux change rates; performing polynomial curve fitting on the change rate sequence; calculating the second derivative of the fitted curve; determining that the LED light decay exhibits nonlinear characteristics when the absolute value of the second derivative is greater than a linear threshold; extrapolating and predicting the cumulative luminous flux attenuation rate of the LED lamp after 1,000 hours of actual use and the cumulative luminous flux attenuation rate after 3,000 hours based on the slope and curvature parameters of the fitted curve; determining that the LED lamp has a long-term light decay risk when the cumulative luminous flux attenuation rate after 1,000 hours exceeds the first attenuation limit or the cumulative luminous flux attenuation rate after 3,000 hours exceeds the second attenuation limit when the cumulative luminous flux attenuation rate after 3,000 hours exceeds the second attenuation limit when the cumulative luminous flux attenuation rate after 1,000 hours exceeds the long-term light decay risk when the LED lamp has a long-term light decay risk when the reliability prediction index is calculated; and applying an additional penalty weight to the LED lamp with a long-term light decay risk when the reliability prediction index is calculated, thereby reducing its comprehensive quality index score.

[0031] In one example, the steady-state temperature and junction temperature compensation coefficient of the LED luminaire are collected, and steady-state photoelectric parameters are constructed based on the steady-state temperature and junction temperature compensation coefficient, including: The resistance of the LED lamp substrate is collected and converted into the substrate temperature. The temperature change rate of adjacent sampling points is calculated. When the temperature change rate is less than the preset threshold and the temperature is lower than the set value, the LED lamp is determined to be in a steady state and the steady state temperature is obtained. The steady-state junction temperature is calculated based on the steady-state temperature, ambient temperature, LED thermal resistance, and power dissipation. The junction temperature compensation coefficient is then calculated based on the steady-state junction temperature and the reference junction temperature. The steady-state photoelectric parameters are obtained by calculating the luminous flux, target color temperature, color rendering index, dominant wavelength, and color coordinate deviation based on the steady-state temperature and correcting them by combining the junction temperature compensation coefficient.

[0032] In this example, after the LED luminaire enters the steady-state conditioning region, due to the large amount of heat accumulated during the multi-stress aging process, the chip junction temperature is in a non-operating steady state. Therefore, the substrate temperature is measured in real time using an NTC thermistor pre-attached to the back of the LED substrate. The NTC thermistor uses a standard model such as MF52-103F3950, and its non-linear relationship with temperature is calculated using the Steinhart-Hart formula, i.e., T(t) = 1 / [A + B·ln(R) + C·ln(R)]. 3 [(R)] - 273.15, where A, B, and C are thermistor parameter constants, and R is the resistance value acquired in real time. This resistor is connected to the acquisition circuit via a sliding contact. The industrial control computer continuously acquires the temperature sequence at a frequency of 5Hz, calculates the temperature change rate dT / dt between every two adjacent sampling points, and triggers the "thermal balance confirmation" condition when the rate of change is less than a preset threshold (e.g., 0.3℃ / s) and the absolute temperature is lower than a set steady-state threshold (e.g., 90℃) for several consecutive times. This confirms that the LED lamp has entered a thermal balance state and sets the temperature T at this time... 热平衡 As the thermal equilibrium substrate temperature. Based on the ambient temperature T 环境 LED thermal resistance R 热 and the actual power dissipation P of the LED 耗散 Calculate the thermal equilibrium junction temperature T of the LED. 结 = T 热平衡 + R 热 × P 耗散 This value reflects the core temperature rise of the chip's PN junction under actual heat dissipation conditions. It is then compared with the standard test reference junction temperature T. 参考 (Using 25℃) for comparison, based on the empirical formula Φ(T) 结 ) = Φ 参考 ×[1 - β × (T 结 - T 参考 The junction temperature compensation coefficient K is constructed. 补偿 = 1 / [1 - β × (T 结 - T 参考 ]], where β is the optical temperature drift coefficient of luminous flux decreasing with temperature (taken as 0.004~0.008 / ℃). Based on the junction temperature compensation coefficient, the various photoelectric parameters measured at non-standard temperatures are uniformly corrected to the values ​​at the equivalent reference temperature. When the LED lamp enters the test station, after applying the rated operating voltage to the lamp, the full spectrum data S(λ) is collected by a spectrometer, and the actual luminous flux Φ is calculated. 实测Five photoelectric parameters are considered: color temperature (CCT), color rendering index (Ra), dominant wavelength (λd), and offset from the reference color coordinates (Δu'v'). These parameters are corrected based on a junction temperature compensation coefficient. For example, luminous flux is expressed as Φ... 修正 =Φ 实测 × K 补偿 Compensation is performed, and color temperature is determined by CCT. 修正 = CCT × [1 + α CCT × (T 热平衡 - T 参考 )] Correction, where α CCT This is the linear coefficient of color temperature drift with temperature (approximately 2K / ℃). After the above correction, Φ... 修正 CCT 修正 Ra, λd, and Δu'v' are the thermal equilibrium photoelectric parameters, reflecting the luminous performance of the LED under standard temperature conditions. The process involves: collecting the substrate resistance of the LED luminaire and converting it into substrate temperature; calculating the temperature change rate between adjacent sampling points; determining that the LED luminaire is in a steady state and acquiring its steady-state temperature when the temperature change rate is less than a preset threshold and the temperature is lower than a set value; acquiring the substrate temperature between two adjacent samplings within the thermal steady-state adjustment zone; calculating the temperature decay time constant; determining that the temperature decay time constant has converged when the standard deviation of multiple consecutive calculated values ​​is less than a convergence threshold; predicting the steady-state arrival time based on the converged temperature decay time constant; calculating the time difference between the steady-state arrival time and the time required for the LED luminaire to reach the test station; reducing the transmission speed of the conductive rail via a servo motor when the time difference is greater than zero to ensure the LED luminaire reaches a steady state before entering the test station; maintaining the original transmission speed of the conductive rail and triggering the test process in advance when the time difference is less than zero; recording the mapping relationship between the temperature decay time constant and the steady-state arrival time for LED luminaires of different power levels, establishing a power-thermal time constant database, and predicting the steady-state arrival time of subsequent LED luminaires of the same power level based on the database and adjusting the rail speed in advance.

[0033] The steady-state junction temperature is calculated based on steady-state temperature, ambient temperature, LED thermal resistance, and power dissipation. A junction temperature compensation coefficient is calculated based on the steady-state junction temperature and a reference junction temperature. The calculation also includes: power classification based on the rated power of the LED luminaire; classifying LED luminaires with power less than 5 watts as low-power and setting a first temperature change rate threshold and a first steady-state waiting time; classifying LED luminaires with power between 5 watts and 20 watts as medium-power and setting a second temperature change rate threshold and a second steady-state waiting time; and classifying LED luminaires with power greater than 20 watts as high-power and setting a third temperature change rate threshold and a third steady-state waiting time. For each power level, a corresponding temperature change rate threshold is selected for steady-state determination. Simultaneously, the heat dissipation efficiency is calculated based on the ratio of rated power to measured dissipation power. When the heat dissipation efficiency is less than the efficiency threshold, the LED lamp is judged to have poor heat dissipation performance, and the steady-state waiting time is increased. When calculating the junction temperature compensation coefficient, a first temperature compensation coefficient is used for low power levels, a second temperature compensation coefficient is used for medium power levels, and a third temperature compensation coefficient is used for high power levels. The third temperature compensation coefficient is greater than the second temperature compensation coefficient, and the second temperature compensation coefficient is greater than the first temperature compensation coefficient, thereby realizing differentiated temperature compensation correction based on power level.

[0034] In one example, luminous flux, target color temperature, color rendering index, dominant wavelength, and color coordinate deviation are calculated based on steady-state temperature and corrected using a junction temperature compensation coefficient to obtain steady-state photoelectric parameters, including: After the LED lamp is in a steady state, steady-state full-spectrum data is collected by the spectrometer built into the integrating sphere, and spectral irradiance data is generated based on the steady-state full-spectrum data. Calculate luminous flux, target color temperature, color rendering index, dominant wavelength, and color coordinate deviation based on spectral irradiance data; The luminous flux and target color temperature are corrected based on the junction temperature compensation coefficient to obtain the corrected luminous flux. The corrected luminous flux, target color temperature, color rendering index, dominant wavelength, and color coordinate deviation are combined as steady-state photoelectric parameters.

[0035] In this example, the test process is triggered by thermal equilibrium conditions. Integrating sphere spectral analysis is used as the main channel, combined with a spectral quantization model for calculation. After the LED lamp has cooled naturally, its substrate temperature is monitored to meet the steady-state judgment condition, i.e., the temperature change rate is continuously lower than the threshold and the temperature value is stable within the set range. This is considered as the LED entering thermal equilibrium, and an integrating sphere measurement station with an opening is set directly below it. The LED working surface faces the light-transmitting hole of the integrating sphere. The industrial control system applies the rated voltage through a contact power supply device to enable the LED to light up normally and output luminous energy stably. The integrating sphere contains a fiber optic spectrometer for full-spectrum measurement. The typical configuration is a 500mm diameter sphere coated with a high-reflectance diffuse reflection coating. The spectrometer samples the wavelength range from 380 to 780 nanometers, completes spectral scanning within the set integration time range, and outputs a wavelength-irradiance dot matrix to form a spectral irradiance data set S(λ). The total luminous flux is calculated from the spectral irradiance data using the formula Φ = 683 × ∑[S(λ] i ) × V(λ i V(λ) × Δλ], where V(λ) is the light efficiency function of human visual perception, and Δλ is the wavelength interval. Using the CIE standard colorimetric definition, the tristimulus values ​​X, Y, and Z are calculated, and then the color coordinates u′ and v′ are converted. The target color temperature CCT is obtained using the McCamy approximation formula. The color rendering index Ra is obtained by calculating the color difference of 14 standard color samples. The dominant wavelength λd is determined based on the position of the maximum value of the S(λ) curve, and the color coordinate deviation Δu′v′ is the Euclidean distance between the measurement point and the target reference color coordinates. After obtaining the above initial photoelectric parameters, to eliminate the optical offset error caused by the high steady-state junction temperature, a junction temperature compensation coefficient K is introduced. 补偿 This is then applied to luminous flux and color temperature correction. The luminous flux correction formula is Φ. 修正 = Φ × K 补偿 The color temperature correction formula is CCT. 修正 = CCT × [1 + α CCT × (T 热平衡 - T 参考 )], where α CCT This is the color temperature drift coefficient, with a value of approximately 2K / ℃. Φ 修正 CCT 修正 The combination of Ra, λd, and Δu′v′ serves as the steady-state photoelectric parameter set for LED lamps.

[0036] In one example, luminous flux, target color temperature, color rendering index, dominant wavelength, and color coordinate deviation are calculated based on spectral irradiance data, including: The luminous flux is obtained by multiplying each wavelength point in the spectral irradiance data with the visual spectral luminous efficiency function, summing the results, and then multiplying by a constant. The three chromaticity components are obtained by multiplying each wavelength point in the spectral irradiance data with the standard chromaticity observer function and summing the results. The chromaticity coordinates are then calculated based on the three chromaticity components. The target color temperature is calculated based on color coordinates. The wavelength corresponding to the maximum value in the spectral irradiance data is taken as the principal wavelength, and the color coordinate deviation between the color coordinates and the nominal color coordinates is calculated. The color difference of each color sample under LED lighting is calculated based on spectral irradiance data and the reflectance spectrum of standard color samples, and the color rendering index is calculated based on the color difference of multiple color samples.

[0037] In this example, the spectral irradiance data S(λ) output by the spectrometer is discretely integrated at a set wavelength interval Δλ, and S(λ) at each wavelength point is... i Multiply by the visual spectral luminous efficiency function V(λ) corresponding to the wavelength i Then, summing across the entire wavelength range and multiplying by the constant 683, we obtain the total luminous flux Φ = 683 × ∑[S(λ i ) × V(λ i The calculation, S(λ) × Δλ, reflects the total luminous output of the LED spectrum under visual sensitivity weighting, conforming to human visual perception standards. S(λ) is then compared with the CIE 1931 standard colorimetric observer function x. 均 (λ), y 均 (λ), z 均 (λ) Multiply each value point by point and sum them to form the tristimulus value component X = ∑[S(λ)] i ) × x 均 (λ i ) × Δλ],Y = ∑[S(λ i ) × y 均 (λ i ) × Δλ],Z = ∑[S(λ i ) × z 均 (λ i The chromaticity coordinates are calculated by transforming the chromaticity coordinates (u′, v′) using the CIE 1976 standard formula: u′ = 4X / (X + 15Y + 3Z), v′ = 9Y / (X + 15Y + 3Z). Based on this, the target color temperature (CCT) is derived using the McCamy approximation formula, where n = (u′ - 0.292) / (v′ - 0.24). This is then substituted into the empirical polynomial CCT = -449n. 3 +3525n 2 - 6823.3n + 5520.33 yields the target color temperature corresponding to the LED spectrum. Simultaneously, the wavelength position λ with the largest value in S(λ) is selected.i That is, S(λ) i ) = max[S(λ)], which is taken as the dominant wavelength λd, reflecting the concentration center of the LED spectral energy distribution. The currently calculated (u′, v′) is compared with the nominal color coordinates (u′) specified in the product design. 标称 , v′ 标称 Perform Euclidean distance calculation, i.e., Δu′v′ = √[(u′ - u′)] 标称 ) 2 + (v′ - v′ 标称 ) 2 [λ] is used as an indicator to evaluate the degree of color deviation of LEDs. To evaluate the ability of LEDs to reproduce standard colors, S(λ) is compared with the reflectance curves of 14 standard color samples defined by CIE. i (λ) The reflectance spectra of each color sample under LED lighting are obtained by multiplying them point by point, and then converted into Lab spatial parameters. These parameters are then compared with the Lab parameters under the D65 standard light source to obtain the color difference ΔE for each color sample. i = √[(ΔL*) 2 + (Δa*) 2 +(Δb*) 2 Summing all color differences and substituting them into the formula Ra = 100 - 4.6 × ∑(ΔE) i ) / 14, the final color rendering index Ra.

[0038] In one example, a comprehensive quality index is calculated based on steady-state photoelectric parameters, high-temperature stress response parameters, voltage stress response parameters, and spectral characteristic parameters. The quality grade of the LED luminaire is then determined based on this comprehensive quality index, including: Calculate the optical performance evaluation index based on steady-state photoelectric parameters; The reliability prediction index is calculated based on high-temperature stress response parameters, voltage stress response parameters, and spectral characteristic parameters. The comprehensive quality index is calculated based on the optical performance evaluation index and the reliability prediction index. When the comprehensive quality index is greater than the first threshold and the deviation of all individual parameters is less than the first deviation limit, the quality grade of the LED lamp is determined to be Grade A. When the comprehensive quality index is between the first threshold and the second threshold, the quality grade of the LED lamp is determined to be Grade B. When the comprehensive quality index is less than the second threshold or the deviation of any individual parameter is greater than the second deviation limit, the quality grade of the LED lamp is determined to be unqualified.

[0039] In this example, based on steady-state photoelectric parameters, including luminous flux Φ 修正 Target color temperature CCT 修正The optical performance evaluation index Q is constructed by normalizing the relative errors between each parameter and its target value, based on the color rendering index Ra, dominant wavelength λd, and color coordinate deviation Δu′v′, and then according to the weights set according to the product application scenario. 光学 Q 光学 = w1×(Φ 修正 / Φ 目标 ) + w2×[1 - |CCT 修正 - CCT 目标 | / (0.1×CCT 目标 )] + w3×(Ra / 100) + w4×[1 - |λd - λd 目标 | / 10] + w5×[1 - Δu′v′ / 0.015], where w1 to w5 are weighting coefficients, and their specific values ​​are set according to the lighting application (such as indoor lighting or display backlighting), for example [0.40, 0.25, 0.20, 0.10, 0.05]. Reliability prediction index Q 可靠 Based on the structural parameters extracted from the previous stress aging processes, including the luminous flux attenuation rate η under high-temperature stress. T Voltage stress response asymmetry γ V Spectral attenuation acceleration a 衰 Spectral response inhomogeneity σ 衰 and color temperature shift acceleration a CCT By setting acceptable ranges and penalty functions for each parameter, the degree of exceeding limits is transformed into a deduction item, thus constructing a reliability index function Q. 可靠 = 1.0 - [k1×max(0, a 衰 - 0.002) + k2×max(0, σ 衰 - 0.3) + k3×max(0, |γ V - 1.0| - 0.2) + k4×max(0, |a CCT | -15) / 15], where k1 to k4 are penalty coefficients, reflecting the sensitivity to abnormal attenuation trends, discrete spectral responses, asymmetric voltage responses, and accelerated color temperature drift, respectively. Typical values ​​are [100, 0.5, 0.3, 0.2]. The max function is used to achieve no penalty below the threshold and linear or stepwise penalty after exceeding the threshold. Q 光学 With Q 可靠 The comprehensive quality index Q is calculated by weighting the components. 总 = 0.7×Q 光学 + 0.3×Q 可靠 Q 总 Compared with the set two-level quality threshold, if Q总 If the deviation of each of the five photoelectric parameters is greater than the first threshold (e.g., 0.95) and the deviation of each parameter is less than the first deviation limit (e.g., 5%), then the LED lamp is classified as Grade A, indicating that it possesses both high performance and stable reliability; if Q 总 The value lies between the first threshold and the second threshold (e.g., 0.88~0.95), or although it satisfies Q... 总 However, if any deviation falls between the first and second deviation limits (e.g., 5%~10%), it is classified as a Grade B product, meaning it is functionally qualified but slightly deviates from certain indicators; if Q 总 Below the second threshold, or any single parameter deviation exceeding the second deviation limit (e.g., greater than 10%), or Q 可靠 If the product falls below the minimum reliability guarantee value (e.g., 0.7), it will be marked as a defective product, triggering an audible and visual alarm and a sorting instruction to move it into the defective recycling channel.

[0040] The comprehensive quality index is calculated based on the optical performance evaluation index and the reliability prediction index. This also includes: real-time statistical analysis of the average luminous flux, average correlated color temperature, average color rendering index, average luminous flux decay acceleration, and average decay non-uniformity of all LED luminaires within a continuous time window; calculation of the deviation of each parameter's average from the target value; triggering a process adjustment warning signal when the deviation of any parameter exceeds the warning threshold; determining the front-end process adjustment direction based on the parameter type corresponding to the warning signal; generating an adjustment instruction to increase the die-attach adhesive coating amount when the average luminous flux is low; generating an adjustment instruction to adjust the phosphor ratio when the correlated color temperature is off; generating an adjustment instruction to increase the proportion of red phosphor when the color rendering index is low; and generating an adjustment instruction to reduce the wire bonding temperature when the luminous flux decay acceleration is too high; sending the adjustment instructions to the front-end process equipment via a communication protocol; continuously monitoring the changing trend of LED luminaire quality parameters within subsequent time windows after process parameter adjustments; confirming the effectiveness of the process adjustment and maintaining the adjusted parameters when the quality parameter deviation decreases below the warning threshold; and reverting the process parameters and generating an abnormal process alarm signal when the quality parameter deviation does not improve.

[0041] The calculation of the optical performance evaluation index based on steady-state photoelectric parameters also includes: obtaining the application scenario identifier of the LED luminaire; when the application scenario identifier is indoor lighting, setting the weight of luminous flux to 0.40, correlated color temperature to 0.25, color rendering index to 0.20, dominant wavelength to 0.10, and color coordinate deviation to 0.05; when the application scenario identifier is display backlighting, setting the weight of luminous flux to 0.30, correlated color temperature to 0.35, color rendering index to 0.15, dominant wavelength to 0.15, and color coordinate deviation to 0.05; and calculating the steady-state photoelectric parameters based on the weight configuration corresponding to the application scenario. The normalized deviations of each parameter from the target value are calculated, and the summation of each normalized deviation multiplied by its corresponding weight yields an optical performance evaluation index that is adaptive to the application scenario. The distribution of actual failure cases caused by abnormal stress response parameters in historical production data is statistically analyzed. When the proportion of failures caused by excessive luminous flux attenuation acceleration exceeds the first threshold, the penalty coefficient for luminous flux attenuation acceleration in the reliability prediction index calculation is increased. When the proportion of failures caused by excessive voltage stress response asymmetry exceeds the second threshold, the penalty coefficient for voltage stress response asymmetry is increased. This achieves dynamic optimization of reliability evaluation weights based on failure mode statistics.

[0042] Reference Figure 2 This embodiment provides a process control system for LED lamp manufacturing, including: Acquisition module 1 is used to collect high-temperature stress response parameters after aging the LED lamp in a high-temperature stress zone; to apply high voltage stress and low voltage stress to the LED lamp sequentially and collect voltage stress response parameters; and to apply switching impact stress to the LED lamp and collect spectral characteristic parameters. Module 2 is used to collect the steady-state temperature and junction temperature compensation coefficient of the LED lamp, and to construct steady-state photoelectric parameters based on the steady-state temperature and junction temperature compensation coefficient. The grading module 3 is used to calculate the comprehensive quality index based on steady-state photoelectric parameters, high-temperature stress response parameters, voltage stress response parameters, and spectral characteristic parameters, and to determine the quality level of the LED lamps based on the comprehensive quality index.

[0043] In this embodiment, the specific implementation of each unit in the above system embodiment is described in the above method embodiment, and will not be repeated here.

[0044] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, system, article, or method that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, system, article, or method. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, system, article, or method that includes that element.

[0045] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A process control method for LED lamp manufacturing, characterized in that, include: High-temperature stress response parameters were collected after the LED lamps were aged in a high-temperature stress zone. High voltage stress and low voltage stress were applied sequentially to the LED lamp, and voltage stress response parameters were collected. A switching impact stress is applied to the LED lamp and spectral characteristic parameters are collected; The steady-state temperature and junction temperature compensation coefficient of the LED lamp are collected, and steady-state photoelectric parameters are constructed based on the steady-state temperature and the junction temperature compensation coefficient. The comprehensive quality index is calculated based on the steady-state photoelectric parameters, the high-temperature stress response parameters, the voltage stress response parameters, and the spectral characteristic parameters, and the quality grade of the LED lamp is determined based on the comprehensive quality index.

2. The process control method for LED lamp manufacturing according to claim 1, characterized in that, After aging the LED lamps in a high-temperature stress zone, high-temperature stress response parameters were collected; high-voltage stress and low-voltage stress were applied to the LED lamps sequentially, and voltage stress response parameters were collected. Applying switching impact stress to the LED lamp and collecting spectral characteristic parameters includes: Before the LED lamp is mounted on the conductive rail, initial full-spectrum data at room temperature is collected by an integrating sphere to calculate the initial luminous flux and initial color temperature, and the initial luminous flux and initial color temperature are used as optical reference values. The LED lamp is aged in a high-temperature stress zone. At the exit of the high-temperature stress zone, the first stress full spectrum data is collected and the first stress luminous flux and stress color temperature are calculated. Based on the optical reference value, the first luminous flux change rate and color temperature shift are calculated. The first luminous flux change rate and the color temperature shift are used as high-temperature stress response parameters. A second stress full-spectrum data is collected by applying high voltage stress to the LED lamp, and then a third stress full-spectrum data is collected by applying low voltage stress to the LED lamp. The voltage stress response parameters are calculated based on the second stress full-spectrum data and the third stress full-spectrum data. A switching impact stress is applied to the LED lamp and the fourth stress full spectrum data is collected. Spectral characteristic parameters are calculated based on the fourth stress full spectrum data.

3. The process control method for LED lamp manufacturing according to claim 2, characterized in that, A second stress full-spectrum data is collected by applying high voltage stress to the LED lamp, and then a third stress full-spectrum data is collected by applying low voltage stress to the LED lamp. Voltage stress response parameters are calculated based on the second and third stress full-spectrum data, including: The LED lamp is subjected to high voltage stress in a high voltage stress zone. Second stress full spectrum data is collected at the exit of the high voltage stress zone and the second stress luminous flux is calculated. The second luminous flux change rate is calculated based on the first stress luminous flux and the second stress luminous flux. The LED lamp is subjected to low voltage stress in a low voltage stress zone. At the exit of the low voltage stress zone, the full spectrum data of the third stress is collected and the luminous flux of the third stress is calculated. The rate of change of the third luminous flux is calculated based on the luminous flux of the second stress and the luminous flux of the third stress. The voltage stress response asymmetry is calculated based on the second luminous flux change rate and the third luminous flux change rate, and the voltage stress response asymmetry is used as the voltage stress response parameter.

4. The process control method for LED lamp manufacturing according to claim 3, characterized in that, A switching impact stress is applied to the LED lamp, and fourth stress full-spectrum data is collected. Spectral characteristic parameters are calculated based on the fourth stress full-spectrum data, including: The LED lamp is passed through the switch impact stress zone. At the exit of the switch impact stress zone, the full spectrum data of the fourth stress is collected and the luminous flux of the fourth stress is calculated. Based on the luminous flux of the third stress and the luminous flux of the fourth stress, the rate of change of the fourth luminous flux is calculated. Based on the first luminous flux change rate, the second luminous flux change rate, the third luminous flux change rate, and the fourth luminous flux change rate, the luminous flux attenuation acceleration and attenuation non-uniformity are calculated, and the luminous flux attenuation acceleration and attenuation non-uniformity are used as spectral characteristic parameters.

5. The process control method for LED lamp manufacturing according to claim 4, characterized in that, Based on the first rate of change of luminous flux, the second rate of change of luminous flux, the third rate of change of luminous flux, and the fourth rate of change of luminous flux, the luminous flux attenuation acceleration and attenuation non-uniformity are calculated, and the luminous flux attenuation acceleration and attenuation non-uniformity are used as spectral characteristic parameters, including: Calculate the difference between the fourth rate of change of luminous flux and the first rate of change of luminous flux, and calculate the luminous flux attenuation acceleration based on the difference in the rate of change; Calculate the standard deviation and mean of the first luminous flux change rate, the second luminous flux change rate, the third luminous flux change rate, and the fourth luminous flux change rate; Dividing the standard deviation by the mean yields the attenuation non-uniformity. The luminous flux attenuation acceleration and the attenuation non-uniformity are combined as spectral characteristic parameters.

6. The process control method for LED lamp manufacturing according to claim 1, characterized in that, The steady-state temperature and junction temperature compensation coefficient of the LED lamp are collected, and steady-state photoelectric parameters are constructed based on the steady-state temperature and the junction temperature compensation coefficient, including: The resistance of the LED lamp substrate is collected and converted into the substrate temperature. The temperature change rate of adjacent sampling points is calculated. When the temperature change rate is less than a preset threshold and the temperature is lower than a set value, the LED lamp is determined to be in a steady state and the steady state temperature is obtained. The steady-state junction temperature is calculated based on the steady-state temperature, ambient temperature, LED thermal resistance, and power dissipation. The junction temperature compensation coefficient is calculated based on the steady-state junction temperature and the reference junction temperature. Based on the steady-state temperature, the luminous flux, target color temperature, color rendering index, dominant wavelength, and color coordinate deviation are calculated and corrected using the junction temperature compensation coefficient to obtain the steady-state photoelectric parameters.

7. The process control method for LED lamp manufacturing according to claim 6, characterized in that, Based on the steady-state temperature, the luminous flux, target color temperature, color rendering index, dominant wavelength, and color coordinate deviation are calculated and corrected using the junction temperature compensation coefficient to obtain steady-state photoelectric parameters, including: After the LED lamp is in a steady state, steady-state full-spectrum data is collected by the spectrometer built into the integrating sphere, and spectral irradiance data is generated based on the steady-state full-spectrum data. The luminous flux, target color temperature, color rendering index, dominant wavelength, and color coordinate deviation are calculated based on the spectral irradiance data. The luminous flux and the target color temperature are corrected according to the junction temperature compensation coefficient to obtain the corrected luminous flux. The corrected luminous flux, target color temperature, color rendering index, dominant wavelength and color coordinate deviation are combined as steady-state photoelectric parameters.

8. The process control method for LED lamp manufacturing according to claim 7, characterized in that, The luminous flux, target color temperature, color rendering index, dominant wavelength, and color coordinate deviation are calculated based on the spectral irradiance data, including: The luminous flux is obtained by multiplying each wavelength point in the spectral irradiance data by the visual spectral luminous efficiency function, summing the results, and then multiplying by a constant. The three chromaticity components are obtained by multiplying each wavelength point in the spectral irradiance data with the standard chromaticity observer function and summing the results. The chromaticity coordinates are then calculated based on the three chromaticity components. The target color temperature is calculated based on the color coordinates, the wavelength corresponding to the maximum value in the spectral irradiance data is taken as the main wavelength, and the color coordinate deviation between the color coordinates and the nominal color coordinates is calculated. The color difference of each color sample under LED lighting is calculated based on the spectral irradiance data and the reflectance spectrum of the standard color sample, and the color rendering index is calculated based on the color difference of multiple color samples.

9. The process control method for LED lamp manufacturing according to claim 1, characterized in that, A comprehensive quality index is calculated based on the steady-state photoelectric parameters, the high-temperature stress response parameters, the voltage stress response parameters, and the spectral characteristic parameters. The quality grade of the LED luminaire is then determined based on the comprehensive quality index, including: Calculate the optical performance evaluation index based on the steady-state photoelectric parameters; The reliability prediction index is calculated based on the high-temperature stress response parameters, the voltage stress response parameters, and the spectral characteristic parameters. The comprehensive quality index is calculated based on the optical performance evaluation index and the reliability prediction index. When the comprehensive quality index is greater than the first threshold and the deviation of all individual parameters is less than the first deviation limit, the quality grade of the LED lamp is determined to be Grade A. When the comprehensive quality index is between the first threshold and the second threshold, the quality grade of the LED lamp is determined to be Grade B. When the comprehensive quality index is less than the second threshold or the deviation of any individual parameter is greater than the second deviation limit, the quality grade of the LED lamp is determined to be unqualified.

10. A process control system for LED lamp manufacturing, characterized in that, The steps for implementing the process control method for manufacturing LED lamps according to any one of claims 1 to 9 include: The acquisition module is used to acquire high-temperature stress response parameters after the LED lamp has been aged in a high-temperature stress zone; to apply high voltage stress and low voltage stress to the LED lamp sequentially and acquire voltage stress response parameters; and to apply switching impact stress to the LED lamp and acquire spectral characteristic parameters. A construction module is used to collect the steady-state temperature and junction temperature compensation coefficient of the LED lamp, and to construct steady-state photoelectric parameters based on the steady-state temperature and the junction temperature compensation coefficient; The grading module is used to calculate a comprehensive quality index based on the steady-state photoelectric parameters, the high-temperature stress response parameters, the voltage stress response parameters, and the spectral characteristic parameters, and to determine the quality grade of the LED lamps based on the comprehensive quality index.

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