A lamp adjusting system based on indoor environment perception of internet of things

Abstract

The present application relates to the technical field of lighting control, and particularly relates to a lamp adjustment system based on indoor environment sensing of Internet of Things, which comprises: a main control layer sensing unit for collecting indoor temperature and overall indoor illumination; a correction layer sensing unit for collecting outer wall surface temperature and window edge illumination; a basic target determination unit for determining a color temperature basic value and a brightness basic value; a thermal inertia correction unit for determining a time shift factor and a rate factor based on the change rate of the inner surface temperature of the outer wall, and determining a virtual temperature based on the time shift factor; a boundary constraint unit for constraining the effective values of the time shift factor and the rate factor; an adjustment instruction generation unit for determining a color temperature adjustment rate based on the constrained rate factor, and generating a color temperature adjustment instruction and a brightness adjustment instruction; and an Internet of Things communication unit for issuing the above instructions to a lamp controller and interacting with a cloud platform to receive parameter configurations. The present application solves the problem of misalignment between light color adjustment and indoor thermal sensing of the existing system.

Description

Technical Field

[0001] This invention relates to the field of lighting control technology, and in particular to a lighting adjustment system based on Internet of Things (IoT) indoor environment sensing. Background Technology

[0002] With the continuous development of building intelligence technology, automatic adjustment systems for indoor lighting have gradually become an important part of smart homes and smart buildings. Existing intelligent lighting adjustment systems typically collect indoor illuminance information through built-in light sensors and automatically compensate for the brightness output of the lights based on preset brightness thresholds. Some systems also introduce color temperature adjustment functions, switching the color temperature of the lights from cool white light to warm yellow light at specific times by setting a fixed schedule to simulate the diurnal variation of natural light, achieving a "sunset mode" or "sleep mode." With the popularization of IoT technology, these systems are gradually evolving towards cloud-based solutions, forming IoT lighting control systems with sensor data collection, local controller execution, and cloud parameter configuration as their basic architecture, possessing basic capabilities such as remote configuration and multi-device linkage. The core adjustment basis of such systems is the real-time measurement of indoor light intensity or the theoretical sunset time calculated based on geographical location and calendar information.

[0003] However, the aforementioned existing technologies have the following technical problems in practical applications: the adjustment logic for illuminance and color temperature is relatively fixed, and the parameter source is singular; the building envelope, such as exterior walls and floors, generally exhibits thermal inertia, meaning that the solar radiation heat stored within it continues to be released into the room after the external radiation intensity decreases, causing changes in the indoor thermal environment to lag behind changes in outdoor light intensity. Existing lighting adjustment systems only use instantaneous indoor illuminance or a fixed schedule as the basis for adjustment, failing to detect the existence of the aforementioned thermal inertia effect. This results in indoor air temperature remaining at a high level even when external light intensity has significantly decreased and the lighting fixtures have entered a warm yellow light adjustment state, creating a significant perceptual conflict between the warm light environment and the perceived heat, affecting user comfort. Furthermore, the existing systems have a fixed adjustment rate, insufficient adaptability to different building types and seasonal conditions, and lack a parameterized configuration mechanism tailored to the thermal inertia characteristics of buildings.

[0004] Chinese Patent Publication No. CN119729934A discloses an indoor lighting control method and system based on the Internet of Things (IoT), comprising: collecting indoor spectral distribution data through a spectral analyzer; constructing a spectral feature fingerprint database using an edge computing unit; and matching and classifying the spectral feature fingerprints based on distributed computing nodes; inputting the spectral feature fingerprints into a preset photophysiological mapping model to generate a spectral compensation sequence, the spectral compensation sequence containing the target output ratio of different wavelength spectra; converting the spectral compensation sequence into indoor lighting control commands; and executing the indoor lighting control commands through an RGBW multi-color LED array and a microlens array to adjust the lighting environment of various indoor areas. It is evident that the aforementioned indoor lighting control method and system based on the IoT has the following problems: the system uses indoor spectral distribution data as the sole basis for adjustment, generating compensation commands through spectral feature fingerprint matching and a photophysiological mapping model. Its adjustment mechanism is essentially limited to optical dimension perception and compensation, failing to introduce perception of the indoor thermal environment state. It cannot identify the lag effect of indoor thermal environment caused by the thermal inertia of the building envelope. Even after external light weakens, when the indoor temperature remains at a high level, the system will compensate towards warmer colors based on spectral features, conflicting with the user's actual thermal perception. Summary of the Invention

[0005] Therefore, this invention provides a lighting adjustment system based on Internet of Things (IoT) indoor environment sensing to overcome the problem in existing technologies where lighting color temperature adjustment cannot adapt to different building thermal inertia characteristics. To achieve the above objective, this invention provides a lighting adjustment system based on IoT indoor environment sensing, comprising: The main control layer sensing unit includes a first temperature sensor for collecting indoor temperature and a first illuminance sensor for collecting overall indoor illuminance. The correction layer sensing unit includes a second temperature sensor attached to the inner surface of the outer wall to collect the temperature of the inner surface of the outer wall and a second illuminance sensor to collect the illuminance at the window edge. A basic target determination unit is connected to the main control layer perception unit and the correction layer perception unit respectively, and is used to determine the basic color temperature value based on the indoor temperature and the basic brightness value based on the overall indoor illuminance. A thermal inertia correction unit is connected to the correction layer sensing unit and the basic target determination unit, respectively. It is used to determine the time shift factor and rate factor based on the temperature change rate of the inner surface of the outer wall, to perform time shift on the indoor temperature based on the time shift factor to obtain a virtual temperature, and to replace the indoor temperature with the virtual temperature and input it into the basic target determination unit to obtain the color temperature target value. A boundary constraint unit, which is connected to the correction layer sensing unit and the thermal inertia correction unit respectively, is used to constrain the effective values ​​of the time shift factor and the rate factor based on the comparison results of the window edge illuminance change rate with the first change rate threshold and the second change rate threshold respectively. An adjustment command generation unit is connected to the thermal inertia correction unit and the boundary constraint unit, respectively, to determine the color temperature adjustment rate based on the constrained rate factor, generate a color temperature adjustment command based on the color temperature target value and the color temperature adjustment rate, and generate a brightness adjustment command based on the brightness base value. The Internet of Things (IoT) communication unit is connected to the adjustment instruction generation unit to send the color temperature adjustment instruction and the brightness adjustment instruction to the lighting controller and to interact with the cloud platform to receive parameter configuration information. The cloud platform is connected to the IoT communication unit to store parameter configuration information and send the parameter configuration information to the IoT communication unit.

[0006] Furthermore, the thermal inertia correction unit determines the direction of the time-shifting factor based on the rate of temperature change of the inner surface of the outer wall. Wherein, if the rate of change of the temperature of the inner surface of the exterior wall is negative, the time shift factor causes the virtual temperature to lead the current indoor temperature, and the absolute value of the time shift factor is positively correlated with the absolute value of the rate of change of the temperature of the inner surface of the exterior wall. If the rate of change of the temperature on the inner surface of the exterior wall is positive, then the time-shifting factor causes the virtual temperature to lag behind the current indoor temperature.

[0007] Furthermore, the rate factor is negatively correlated with the absolute value of the rate of change of the temperature on the inner surface of the outer wall.

[0008] Furthermore, the boundary constraint unit applies different constraints to the effective values ​​of the time-shifting factor and the rate factor based on the interval to which the absolute value of the window edge illuminance change rate belongs, wherein the interval includes: The rapid change range in which the absolute value of the window edge illuminance change rate is greater than the first change rate threshold; The absolute value of the window edge illuminance change rate is greater than or equal to the second change rate threshold and less than or equal to the first change rate threshold in a gradual change range. Furthermore, the absolute value of the window edge illuminance change rate is less than the stable range of the second change rate threshold.

[0009] Furthermore, based on the judgment result that the absolute value of the window edge illuminance change rate is within the rapid change range, the boundary constraint unit constrains the effective value of the rate factor to a preset minimum value, and keeps the effective value of the time shift factor at its corresponding calculated value; based on the judgment result that the absolute value of the window edge illuminance change rate is within the slow change range, the boundary constraint unit keeps the effective value of the time shift factor at its corresponding calculated value, and keeps the effective value of the rate factor at its corresponding calculated value.

[0010] Furthermore, based on the judgment result that the absolute value of the window edge illuminance change rate is within the stable interval, the boundary constraint unit sets the effective value of the time shift factor to zero and the effective value of the rate factor to a preset default value.

[0011] Furthermore, based on the judgment result that the absolute value of the window edge illuminance change rate is within the rapid change range, the boundary constraint unit outputs a brightness maintenance constraint to the adjustment command generation unit, so that the brightness adjustment command generated by the adjustment command generation unit keeps the current brightness value unchanged and does not update with the change of the overall indoor illuminance.

[0012] Furthermore, the adjustment command generation unit determines the color temperature adjustment rate based on the difference between the target color temperature value and the current color temperature value, and the constrained rate factor; The color temperature adjustment rate is positively correlated with the difference between the target color temperature value and the current color temperature value, and is also positively correlated with the constrained rate factor.

[0013] Furthermore, the base color temperature value determined by the base target determination unit is positively correlated with the indoor temperature; the base brightness value determined by the base target determination unit is negatively correlated with the overall indoor illuminance.

[0014] Furthermore, the parameter configuration information received by the IoT communication unit from the cloud platform includes the first rate of change threshold and the second rate of change threshold; The cloud platform stores parameter configuration packages corresponding to different building thermal inertia types, and sends the corresponding parameter configuration packages to the IoT communication unit based on the building type information.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention introduces a thermal inertia correction unit with the temperature change rate of the inner surface of the outer wall as input, obtains a virtual temperature by time shifting the indoor temperature based on the time shift factor, and determines the target color temperature value accordingly. At the same time, the color temperature adjustment rate is constrained by the rate factor, so that the timing and amplitude of the lamp color temperature adjustment can match the thermal inertia characteristics of the building envelope. This solves the problem that the existing lamp adjustment system uses instantaneous indoor temperature or a fixed time schedule as the basis for adjustment and cannot sense the thermal inertia of the building, resulting in a misalignment between light color adjustment and indoor heat perception.

[0016] Furthermore, by keeping the sign of the time-shifting factor consistent with the sign of the temperature change rate of the inner surface of the exterior wall, the present invention enables the system to achieve an advanced response during the cooling phase of the exterior wall and a delayed response during the heating phase of the exterior wall, so that the timing of color temperature adjustment is adapted to the actual heat transfer direction of the building envelope.

[0017] Furthermore, by designing the rate factor to be negatively correlated with the absolute value of the temperature change rate of the inner surface of the exterior wall, the present invention automatically reduces the color temperature transition rate when the building has low thermal inertia and the exterior wall temperature changes rapidly, thus avoiding perceptible jumps in the color temperature of the lamps caused by rapid changes in the external thermal environment.

[0018] Furthermore, this invention introduces a three-interval judgment mechanism for the window edge illuminance change rate through a boundary constraint unit, and applies segmented constraints to the effective values ​​of the time shift factor and the rate factor, so that the thermal inertia correction logic only takes effect when the external light environment change characteristics match the applicable conditions of the correction logic, and automatically exits the thermal inertia correction state in the stable interval, thus avoiding unnecessary adjustment deviations introduced by the correction factor when the external environment is stable.

[0019] Furthermore, this invention constrains the effective value of the rate factor to a preset minimum value within the rapidly changing range, thereby forcibly reducing the color temperature transition rate during periods of rapid change in external illumination, preventing significant jumps in the color temperature of the lamps within a short period of time, and reducing interference with the user's vision.

[0020] Furthermore, by freezing the brightness adjustment command within a rapidly changing range, the present invention prevents the brightness output from changing with the overall indoor illuminance, thus avoiding the superimposed visual interference to the user caused by the synchronous and rapid changes in the brightness and color temperature of the lamps during the period of sharp decline in outdoor light.

[0021] Furthermore, this invention interacts with the cloud platform through an IoT communication unit, stores and distributes parameter configuration packages according to the building thermal inertia type, so that the same hardware product can obtain control parameters that are compatible with the local thermal inertia characteristics under different building envelope types, and the parameter configuration can be updated remotely through the cloud without replacing the hardware. Attached Figure Description

[0022] Figure 1 This is a connection block diagram of the lighting adjustment system based on Internet of Things indoor environment sensing of the present invention; Figure 2 This is the overall logic block diagram of the lighting adjustment system based on Internet of Things indoor environment sensing of the present invention. Figure 3 This is a logic block diagram of the thermal inertia correction unit of the lighting adjustment system based on Internet of Things indoor environment perception of the present invention; Figure 4 This is a logic block diagram of the boundary constraint unit of the lighting adjustment system based on Internet of Things indoor environment perception according to the present invention. Detailed Implementation

[0023] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0024] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0025] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0026] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0027] Please see Figure 1 and Figure 2 The diagrams shown are a connection block diagram and an overall logic block diagram of the lighting control system based on IoT indoor environment sensing, respectively. This invention provides a lighting control system based on IoT indoor environment sensing, comprising: The main control layer sensing unit includes a first temperature sensor for collecting indoor temperature and a first illuminance sensor for collecting overall indoor illuminance. This invention relates to an IoT-based indoor environment sensing lighting adjustment system, applied to building interior environments. Traditional solutions typically adjust lighting color temperature and brightness based on real-time indoor illuminance or a fixed schedule. However, building exterior walls accumulate heat after receiving solar radiation during the day and continuously release it into the interior through their inner surfaces from evening to night. This causes changes in indoor air temperature to lag behind the decay of outdoor light intensity; conversely, the temperature rise of the exterior walls after sunrise also lags behind the increase in outdoor radiation. This temporal misalignment between the indoor thermal environment and the outdoor light environment, caused by the thermal inertia of the building envelope, makes lighting adjustment strategies based solely on instantaneous illuminance or time difficult to coordinate with the user's perceived thermal comfort. For example: During the late afternoon hours in summer and autumn, in south- or west-facing rooms of an office building, the intensity of outdoor solar radiation weakens as the sun sets, leading to a decrease in natural light intensity near the windows. During this time, the building's exterior walls, having accumulated significant heat from prolonged exposure to solar radiation during the day, continuously release this stored heat into the indoor air through their inner surfaces after the outdoor radiation weakens. This causes the indoor air temperature to drop significantly later than the decrease in outdoor light intensity. If a traditional lighting adjustment solution is used, it simply switches the color temperature of the lights from cool white to warm yellow based on the instantaneous indoor illuminance or a preset fixed schedule, and simultaneously increases brightness to compensate for insufficient illuminance when the illuminance near the windows drops to a certain threshold. However, because the indoor air temperature remains relatively high due to the continuous heat release from the exterior walls, users will simultaneously experience a warm yellow light environment and a perceived temperature that feels too hot, creating a perceptual conflict and reducing comfort. In the early morning hours of winter, the exterior walls are cold after cooling down overnight. After sunrise, outdoor radiation increases rapidly, but the exterior walls heat up slowly, and the indoor temperature rises slowly. If the color temperature of the lamps remains at a high color temperature and warm white light, it will further enhance the feeling of coldness indoors.

[0028] In one specific embodiment, the first temperature sensor is an NTC thermistor temperature sensor or a platinum resistance temperature sensor, installed on a wall at a height of 1.2m to 1.5m above the ground to collect indoor air temperature representing the area of ​​human activity; preferably, a PT100 platinum resistance sensor is used, with a measurement range of -20℃ to 80℃, a measurement accuracy of ±0.3℃, and a sampling period of 30s. The first illuminance sensor is a silicon photodiode type illuminance sensor, installed at the center of the ceiling of the room to collect the overall horizontal illuminance of the room; preferably, the measurement range is 0lx to 65535lx, the measurement accuracy is ±5%, and the sampling period is 10s.

[0029] Understandably, the first temperature sensor is installed at the height of human activity to ensure that the collected indoor temperature reflects the actual thermal environment of the human body's location as much as possible, rather than the temperature of the hot air lingering at the top, thereby improving the accuracy of color temperature adjustment in response to human comfort; the first illuminance sensor is installed at the center of the top to collect the overall indoor illuminance unaffected by local obstructions, making the determination of the baseline brightness value representative.

[0030] The correction layer sensing unit includes a second temperature sensor attached to the inner surface of the outer wall to collect the temperature of the inner surface of the outer wall and a second illuminance sensor to collect the illuminance at the window edge. In one specific embodiment, the second temperature sensor is a thin-film platinum resistance temperature sensor (PT1000), attached to the inner surface of the exterior wall via thermally conductive silicone. The preferred attachment position is at the center of the exterior wall, 1.0m to 1.5m above the ground, avoiding door and window frames and decorative layers. Preferably, its measurement range is -10℃ to 70℃, with a measurement accuracy of ±0.2℃ and a sampling period of 60s. The temperature change rate of the inner surface of the exterior wall is calculated by the control unit using first-order difference calculations on continuous sampling values, with units of ℃ / min. The second illuminance sensor is a silicon photodiode type illuminance sensor, installed on the indoor side near the window, at a horizontal distance of no more than 0.3m from the inner surface of the window glass, to collect window-side illuminance that reflects the changing trend of the outdoor light environment. Preferably, the measurement range is 0lx to 100,000lx, with a measurement accuracy of ±5% and a sampling period of 10s. The window-side illuminance change rate is also calculated by the control unit using first-order difference calculations on continuous sampling values, with units of lx / min.

[0031] Understandably, the temperature of the inner surface of the exterior wall directly reflects the heat storage and release state of the building envelope, and its rate of temperature change can characterize the strength and current stage of the building's thermal inertia. Specifically, after absorbing solar radiation during the day, the exterior wall stores heat, which is continuously released into the room from evening to night. This heat release process causes the decrease in indoor air temperature to lag significantly behind the decrease in outdoor radiation intensity. The larger the absolute value of the negative value of the rate of temperature change of the inner surface of the exterior wall, the more rapidly the building envelope is transferring heat into the room and the relatively small the thermal inertia, meaning the indoor temperature will respond to external changes more quickly. Conversely, a smaller absolute value of the rate of temperature change of the inner surface of the exterior wall indicates a larger building thermal inertia, meaning the indoor thermal environment will remain at a higher level for a longer period. Therefore, using the rate of temperature change of the inner surface of the exterior wall as a correction layer parameter can provide the subsequent thermal inertia correction unit with an input basis reflecting the real-time thermal state of the building envelope, rather than simply relying on the instantaneous value of the indoor air temperature. The second illuminance sensor is installed near the window rather than in the center of the room because the illuminance near the window is most sensitive to changes in the outdoor light environment. Its rate of change can reflect the dynamic trends of the external light environment in advance, such as the sunset rate or sudden weather changes, providing predictive input parameters for the interval judgment of the boundary constraint unit.

[0032] A basic target determination unit is connected to the main control layer perception unit and the correction layer perception unit respectively, and is used to determine the basic color temperature value based on the indoor temperature and the basic brightness value based on the overall indoor illuminance. Specifically, the base color temperature value determined by the base target determination unit is positively correlated with the indoor temperature; the base brightness value determined by the base target determination unit is negatively correlated with the overall indoor illuminance.

[0033] In one specific embodiment, the basic target determination unit uses a piecewise linear interpolation lookup table method to determine the basic color temperature value based on the indoor temperature. Specifically, a correspondence table between indoor temperature and basic color temperature values ​​is pre-stored in the controller storage unit. In this embodiment, the correspondence table is defined as follows: when the indoor temperature is less than or equal to 24℃, the basic color temperature value is 2700K; when the indoor temperature is greater than or equal to 28℃, the basic color temperature value is 5000K; when the indoor temperature is between 24℃ and 28℃, the basic color temperature value is calculated by linear interpolation between 2700K and 5000K. The above temperature segment thresholds and color temperature endpoint values ​​can be adjusted through parameter configuration information issued by the cloud platform.

[0034] Similarly, the basic target determination unit uses a piecewise linear interpolation lookup table method to determine the basic luminance value based on the overall indoor illuminance. Specifically, when the overall indoor illuminance is greater than or equal to 500 lx, the basic luminance value is 20% of the rated luminance of the luminaire; when the overall indoor illuminance is less than or equal to 50 lx, the basic luminance value is 100% of the rated luminance of the luminaire; when the overall indoor illuminance is between 50 lx and 500 lx, the basic luminance value is calculated by linear interpolation between 20% and 100% to compensate for insufficient ambient light; at the same time, the upper limit of the basic luminance value is set not to exceed 100% of the rated luminance of the luminaire to prevent excessive compensation at night.

[0035] It's understandable that the positive correlation between base color temperature and indoor temperature is based on the psychophysical principle of how color temperature affects human thermal perception: cool-colored light (high color temperature) gives a visually refreshing feeling, while warm-colored light (low color temperature) gives a visually warm feeling. When the indoor temperature is high, using high color temperature cool light helps alleviate the subjective feeling of stuffiness to some extent; when the indoor temperature is low, using low color temperature warm light helps enhance the feeling of warmth. The negative correlation between base brightness and overall indoor illuminance is based on the principle of constant illuminance compensation: the lower the overall indoor illuminance, the weaker the contribution of natural or ambient light, and the higher the brightness output of the luminaires needs to maintain the basic level of indoor illuminance; conversely, the brightness of the luminaires should be reduced to avoid over-illumination. Both of these relationships are implemented using piecewise linear functions, a mature and widely used basic adjustment method in the field of lighting control. The parameter endpoints and piecewise thresholds can be adjusted through cloud parameter configuration according to different scenario requirements, making it adaptable.

[0036] A thermal inertia correction unit, which is connected to the correction layer sensing unit and the basic target determination unit respectively, is used to determine the time shift factor and the rate factor based on the temperature change rate of the inner surface of the exterior wall; the indoor temperature is time-shifted based on the time shift factor to obtain a virtual temperature, and the virtual temperature is used to replace the indoor temperature and input into the basic target determination unit to obtain the color temperature target value. Please continue reading. Figure 3 As shown, it is a logic block diagram of the thermal inertia correction unit of the lighting adjustment system based on Internet of Things indoor environment perception of the present invention. Specifically, the thermal inertia correction unit determines the direction of the time shift factor based on the rate of change of the temperature of the inner surface of the exterior wall. If the rate of change of the temperature of the inner surface of the exterior wall is negative, the time shift factor causes the virtual temperature to lead the current indoor temperature, and the absolute value of the time shift factor is positively correlated with the absolute value of the rate of change of the temperature of the inner surface of the exterior wall. If the rate of change of the temperature on the inner surface of the exterior wall is positive, then the time-shifting factor causes the virtual temperature to lag behind the current indoor temperature.

[0037] Specifically, the rate factor is negatively correlated with the absolute value of the rate of change of the temperature on the inner surface of the exterior wall.

[0038] In one specific embodiment, the thermal inertia correction unit calculates the time-shift factor based on the rate of temperature change of the inner surface of the outer wall, using the following formula: φ shift =λ×T wall ; Where, φ shift The time shift factor, measured in minutes (min), is indicated by its sign: positive for lag and negative for lead. T wall λ is the rate of temperature change of the inner surface of the exterior wall, in °C / min. It is calculated by first-order difference from the continuous sampling values ​​of the second temperature sensor in the correction layer sensing unit. A negative sign indicates that the exterior wall is cooling down, and a positive sign indicates that the exterior wall is still heating up. λ is the thermal inertia calibration coefficient, in min. 2 / ℃, with a range of 1.0 min. 2 / ℃~5.0min 2 / ℃, preferably, λ is 2.0 min. 2 / ℃, which is determined according to the type of building envelope, with a smaller value for lightweight walls and a larger value for heavy walls.

[0039] Understandably, when the rate of change of the inner surface temperature of the exterior wall is negative, the time-shift factor is negative, and the virtual temperature is taken from the historical value of the indoor temperature at a certain point before the current moment. This is equivalent to using the "indoor temperature at a certain point in the past" to predict the future color temperature target, achieving an advanced response. When the rate of change of the inner surface temperature of the exterior wall is positive, the time-shift factor is positive, and the virtual temperature is taken from the predicted temperature trend after the current moment, achieving a delayed response. The larger the λ coefficient, the larger the time shift, and the stronger the compensation for the building's thermal inertia.

[0040] In one specific embodiment, the thermal inertia correction unit performs a time shift on the indoor temperature based on the time shift factor to obtain a virtual temperature, calculated as follows: T vir (t)=T room (t-φ shift ); Among them, T vir The temperature is a virtual temperature in °C; t is the current time in minutes (min); T room (t-φ shift The time shift factor φ is the difference between the current time t and the time shift factor φ. shift The corresponding historical indoor temperature value at that moment, in °C; the controller needs to maintain a buffer of historical indoor temperature data for a duration of not less than 30 minutes to support index access to historical temperatures by the time-shift factor; when φshift When it is negative, (t-φ) shift If the value is greater than the current time, then the first-order linear extrapolation value of the indoor temperature, i.e., T, is used instead. vir (t)=T room (t)+∣φ shift |×T room , among which, T room This represents the current rate of change of indoor temperature, expressed in °C / min.

[0041] Subsequently, the thermal inertia correction unit will adjust the virtual temperature T. vir The indoor temperature input base target determination unit is replaced, and the correspondence table between indoor temperature and base color temperature values ​​is consulted to obtain the color temperature target value K. tar The unit is Kelvin (K).

[0042] In one specific embodiment, the thermal inertia correction unit calculates the rate factor based on the rate of change of the temperature on the inner surface of the outer wall, using the following formula: ρ rate =1 / (1+μ×∣T wall |); Where, ρ rate is the rate factor, dimensionless, with a value range greater than 0 and less than or equal to 1; μ is the rate calibration coefficient, with the unit being min / ℃, and a value range of 0.5 min / ℃ to 3.0 min / ℃. Preferably, μ is 1.5 min / ℃, which is calibrated according to different building types and user comfort feedback.

[0043] Understandably, the design principles of the aforementioned time-shifting factor and rate factor are rooted in the mechanism by which the thermal inertia of the building envelope affects the indoor thermal environment. Building exterior walls absorb solar radiation during the day, accumulating heat, and continuously release it into the interior from evening to night. This process causes the decrease in indoor air temperature to lag behind the reduction in outdoor light intensity. Different buildings have significantly different building envelope materials and thicknesses. Lightweight walls have lower heat capacity and faster heat absorption and release rates, resulting in a more rapid response of indoor temperature to external changes. Heavyweight walls have higher heat capacity, and the heat storage and release process lasts longer, causing indoor temperature changes to lag significantly behind changes in external light intensity. In traditional lighting control systems, color temperature adjustment is solely based on the current indoor temperature or current illuminance. Therefore, even when external radiation has weakened and lighting fixtures have been adjusted towards warmer colors, the indoor air temperature may remain at a high level due to the continuous heat release from the walls, leading to a conflict between the warm light environment and a feeling of excessive heat. The purpose of introducing the time-shift factor is to offset the sampling time of indoor temperature on the time axis, so that the temperature information on which the color temperature target value is generated matches the dynamic trend of the actual thermal environment, rather than simply using the current instantaneous temperature. The magnitude of the temperature change rate of the inner surface of the exterior wall reflects the current heat release rate of the building envelope. The faster the heat release rate, the smaller the thermal inertia, and the indoor temperature will follow the external changes more quickly, allowing for a larger time shift; the slower the heat release rate, the greater the thermal inertia, and the indoor temperature will remain high for a longer period, resulting in a correspondingly smaller time shift. The rate factor corrects the adjustment behavior from another dimension: when the absolute value of the temperature change rate of the inner surface of the exterior wall is large, it indicates that the external thermal environment is changing drastically. If the color temperature of the lighting fixtures changes at a relatively fast rate at this time, users will perceive a significant jump in light color, causing visual discomfort; therefore, the rate factor is suppressed when the absolute value of the temperature change rate of the exterior wall is large, making the color temperature transition smoother; conversely, when the absolute value of the temperature change rate of the exterior wall is close to zero, the rate factor approaches its maximum value, and the color temperature adjustment is executed at a rate close to the default. The time-shift factor and the rate factor act on two independent variables, namely the timing of regulation and the smoothness of regulation, respectively, and together constitute a compensation mechanism for the thermal inertia effect of buildings.

[0044] A boundary constraint unit, which is connected to the correction layer sensing unit and the thermal inertia correction unit respectively, is used to constrain the effective values ​​of the time shift factor and the rate factor based on the comparison results of the window edge illuminance change rate with the first change rate threshold and the second change rate threshold respectively. Please continue reading. Figure 4 As shown, it is a logic block diagram of the boundary constraint unit of the lighting adjustment system based on Internet of Things indoor environment perception of the present invention. Specifically, the boundary constraint unit applies different constraints to the effective values ​​of the time-shift factor and the rate factor based on the interval to which the absolute value of the window edge illuminance change rate belongs, wherein the interval includes: The rapid change range in which the absolute value of the window edge illuminance change rate is greater than the first change rate threshold; The absolute value of the window edge illuminance change rate is greater than or equal to the second change rate threshold and less than or equal to the first change rate threshold in a gradual change range. Furthermore, the absolute value of the window edge illuminance change rate is less than the stable range of the second change rate threshold.

[0045] Specifically, the boundary constraint unit outputs a brightness maintenance constraint to the adjustment command generation unit based on the judgment result that the absolute value of the window edge illuminance change rate is in the rapid change range, so that the brightness adjustment command generated by the adjustment command generation unit keeps the current brightness value unchanged and does not update with the change of the overall indoor illuminance.

[0046] Specifically, the boundary constraint unit, based on the judgment result that the absolute value of the window edge illuminance change rate is in the rapid change range, constrains the effective value of the rate factor to a preset minimum value, and keeps the effective value of the time shift factor at its corresponding calculated value; the boundary constraint unit, based on the judgment result that the absolute value of the window edge illuminance change rate is in the slow change range, keeps the effective value of the time shift factor at its corresponding calculated value, and keeps the effective value of the rate factor at its corresponding calculated value.

[0047] Specifically, the boundary constraint unit sets the effective value of the time shift factor to zero and the effective value of the rate factor to a preset default value based on the judgment result that the absolute value of the window edge illuminance change rate is within the stable range.

[0048] In one specific embodiment, the boundary constraint unit uses the absolute value of the window edge illuminance change rate as the judgment criterion, comparing it with a first change rate threshold and a second change rate threshold to divide it into three intervals. In this embodiment, preferably, the first change rate threshold is 500 lx / min, and the second change rate threshold is 50 lx / min. Both thresholds are stored in the parameter configuration package of the cloud platform and can be adjusted by the cloud according to the building orientation and geographical location. The window edge illuminance change rate is calculated by first-order difference from the continuous sampling values ​​of the second illuminance sensor of the correction layer sensing unit, with the unit being lx / min, and its absolute value is used for interval judgment.

[0049] In one specific embodiment, the boundary constraint unit applies the following constraints to the three intervals respectively: Firstly, when the absolute value of the window edge illuminance change rate is greater than the first change rate threshold, it is in the rapid change range. The boundary constraint unit keeps the effective value of the time shift factor unchanged from the calculated value of the thermal inertia correction unit, while constraining the effective value of the rate factor to a preset minimum value. Preferably, the preset minimum value of the rate factor is 0.1, which is dimensionless and is calibrated based on the subjective evaluation experiment that the change in the color temperature of the lamp does not cause obvious visual discomfort to the user.

[0050] Secondly, when the absolute value of the window edge illuminance change rate is greater than or equal to the second change rate threshold and less than or equal to the first change rate threshold, it is in the slow change range. The boundary constraint unit does not impose additional constraints on the effective values ​​of the time shift factor and the rate factor, and both are taken from the calculated values ​​of the thermal inertia correction unit.

[0051] Third, when the absolute value of the window edge illuminance change rate is less than the second change rate threshold, it is in a stable range. The boundary constraint unit sets the effective value of the time shift factor to zero and the effective value of the rate factor to a preset default value. Preferably, the preset default value of the rate factor is 1.0, which is dimensionless, that is, it is restored to the default adjustment rate when there is no thermal inertia correction.

[0052] Understandably, the preset minimum value of the rate factor determines the minimum rate of color temperature transition of the lamp within the rapid change range. The smaller the value, the smoother the color temperature transition and the less disturbance to the user's vision. The preset default value of the rate factor is 1.0, which means that within the stable range, the color temperature adjustment rate returns to the standard value initially set by the system and is not affected by the thermal inertia parameters of the external wall.

[0053] Understandably, the boundary constraint unit introduces the window edge illuminance change rate to impose interval constraints on the time-shifting factor and rate factor. The principle is that the window edge illuminance change rate reflects the current dynamic rate of change in the outdoor light environment, and this rate determines whether the thermal inertia correction logic should be fully effective. During the sunset process, which is in a normal, gradual phase, the outdoor light intensity decreases steadily. The thermal inertia of the exterior wall is the main factor affecting the degree of misalignment between indoor heat perception and light regulation. At this time, the time-shifting factor and rate factor should be allowed to fully take effect according to the calculated values ​​of the thermal inertia correction unit to achieve sufficient compensation for the thermal inertia effect. During periods of rapid change in outdoor light intensity, such as when the sun sets quickly in the summer evening or when the weather changes abruptly, the drastic changes in the external light environment itself become the dominant factor. If the rate factor is still calculated to a large value at this time, the color temperature of the lamps will change rapidly in a short period of time, and users will perceive obvious color changes, causing visual discomfort. Therefore, within this range, the rate factor is constrained to a preset minimum value, forcing the lamps to transition the color temperature at the smoothest rate, while the time-shift factor remains effective to ensure that the direction of the color temperature target value is accurately determined. Conversely, when outdoor light intensity remains stable for an extended period, and the absolute value of the window-side illuminance change rate remains below the second change rate threshold, it indicates that there is neither a sunset process nor a sudden weather change during the current period. The heat input of outdoor radiation to the building envelope has stabilized, and the disturbance effect of the thermal inertia of the exterior walls on the indoor thermal environment is no longer significant. Continuing to maintain the time-shift factor in effect would cause the virtual temperature to deviate from the actual indoor temperature, introducing unnecessary adjustment errors. Therefore, within this interval, the time-shift factor is set to zero, allowing the system to revert to the basic state of directly determining the target color temperature value from a table based on the current indoor temperature. At the same time, the rate factor is restored to its default value to ensure timely adjustment response. The boundary judgment conditions for the three intervals are defined by two configurable change rate thresholds. The difference in the thresholds reflects the natural differences in sunset rates under different building orientations and geographical latitudes, supporting targeted adjustments through cloud-based parameter configuration.

[0054] An adjustment command generation unit is connected to the thermal inertia correction unit and the boundary constraint unit, respectively, to determine the color temperature adjustment rate based on the constrained rate factor, generate a color temperature adjustment command based on the color temperature target value and the color temperature adjustment rate, and generate a brightness adjustment command based on the brightness base value. Specifically, the adjustment command generation unit determines the color temperature adjustment rate based on the difference between the target color temperature value and the current color temperature value, and the constrained rate factor; the color temperature adjustment rate is positively correlated with the difference between the target color temperature value and the current color temperature value, and is also positively correlated with the constrained rate factor.

[0055] In one specific embodiment, the adjustment command generation unit uses a first-order proportional tracking method to determine the color temperature adjustment rate, and the calculation formula is as follows: dK / dt=ρ eff ×(K tar- K cur ) / τ; Where dK / dt is the color temperature adjustment rate, in K / min, representing the change in the color temperature of the lamp per unit time; ρ eff The effective value of the rate factor after being constrained by the boundary constraint element is dimensionless, and its value ranges from greater than 0 to less than or equal to 1. It is output by the boundary constraint element; K tar This is the target color temperature value, in K, output by the thermal inertia correction unit; K cur τ represents the current color temperature of the luminaire, expressed in K, and is fed back in real time by the luminaire controller. τ is the color temperature adjustment time constant, expressed in min, with a range of 1.0 min to 5.0 min. Preferably, τ is 2.0 min, and it is calibrated based on a user subjective comfort evaluation experiment. This calibration process is a conventional subjective evaluation method in this field. Specifically, in a controlled experimental environment, the luminaire color temperature is set to transition from the starting value to the ending value with different time constants. Several subjects subjectively rate the smoothness of the transition process and the visual comfort. The optimal time constant range is determined through statistical analysis, and the median value is taken as the default value to reflect the reference time required for the system to complete one color temperature transition under conditions without thermal inertia correction intervention.

[0056] It is understandable that the color temperature adjustment rate in the above formula is positively correlated with the difference between the target color temperature value and the current color temperature value. A larger difference indicates a greater deviation between the current and target color temperatures, requiring the system to catch up at a faster rate. As the color temperature gradually approaches the target value, the difference decreases, and the adjustment rate automatically decreases, thus achieving smooth convergence rather than abrupt change. The effective value of the rate factor ρ eff As an overall proportional coefficient, it acts on the adjustment rate. The smaller the value, the smoother the color temperature transition. The time constant τ determines the reference response speed of the color temperature transitioning from the current value to the target value when the rate factor takes the default value and the target color temperature is fixed. The larger τ is, the slower the transition.

[0057] In one specific embodiment, the adjustment command generation unit modifies the calculated color temperature adjustment rate dK / dt with the current lamp color temperature value K. cur In combination, the color temperature output value of the lamp is updated recursively according to a fixed control cycle (preferably, the control cycle is 10s), and converted into a corresponding PWM dimming signal or DALI dimming command, which is then sent to the lamp controller. The lamp controller drives the duty cycle of the cool white light channel and the warm white light channel to be output according to the target ratio according to the color temperature adjustment command, so as to realize continuous and smooth adjustment of color temperature.

[0058] In one specific embodiment, the adjustment command generation unit generates a brightness adjustment command that keeps the current brightness value unchanged based on the judgment that the absolute value of the window edge illuminance change rate is in the rapid change range. That is, the brightness output is frozen within this range and does not respond to changes in the overall indoor illuminance. When the absolute value of the window edge illuminance change rate is in the slow change range or the stable range, the adjustment command generation unit determines the basic brightness value output by the unit according to the basic target, generates a brightness adjustment command, and sends it to the lighting controller normally. The brightness adjustment command is also output in the form of a PWM dimming signal or a DALI dimming command to control the duty cycle of the total brightness channel of the lighting fixture.

[0059] It is understandable that the color temperature adjustment adopts a first-order proportional tracking method because the color temperature adjustment target is jointly determined by the thermal inertia correction unit and the boundary constraint unit, and has already undergone joint correction of time shift and rate. The adjustment command generation unit only needs to approach the target value at a controlled rate. Using the difference between the current color temperature and the target color temperature as the driving quantity enables the adjustment process to respond quickly when the deviation is large and automatically slow down when approaching the target, avoiding overshoot and oscillation. The brightness adjustment is forcibly frozen in the rapid change range because when the outdoor light intensity drops sharply, the illuminance at the window will change significantly in a short period of time, and the overall indoor illuminance will also decrease rapidly. If the brightness adjustment continuously increases the brightness output in real time to follow the change of the overall indoor illuminance, the brightness of the lamp will change significantly in a short period of time. During this process, the user will simultaneously perceive the gradual change of color temperature and the rapid increase of brightness. The superposition of the two will cause a relatively significant visual discomfort. Therefore, during periods of rapid change in external light, temporarily freezing the brightness output at the current level and then resuming normal brightness adjustment once the external light environment stabilizes and enters a gradual change range can effectively avoid interference to users caused by short-term strong brightness disturbances, and maintain a relatively stable visual experience in the dynamic process of the overall light environment.

[0060] The Internet of Things (IoT) communication unit is connected to the adjustment command generation unit to send the color temperature adjustment command and the brightness adjustment command to the lighting controller and to interact with the cloud platform to receive parameter configuration information.

[0061] A cloud platform, which is communicatively connected to the IoT communication unit, is used to store parameter configuration information and send the parameter configuration information to the IoT communication unit. Specifically, the parameter configuration information received by the IoT communication unit from the cloud platform includes the first rate of change threshold and the second rate of change threshold; the cloud platform stores parameter configuration packages corresponding to different building thermal inertia types, and sends the corresponding parameter configuration packages to the IoT communication unit based on the building type information.

[0062] In one specific embodiment, the IoT communication unit uses a home smart gateway as an edge communication node. On the local side, it communicates with the lighting controller via Zigbee or Z-Wave wireless protocol, and sends the color temperature adjustment command and the brightness adjustment command to the lighting controller in the form of a standard dimming control frame. On the cloud side, it accesses the Internet via Wi-Fi or Ethernet, and maintains a long connection with the cloud platform using the MQTT protocol to achieve bidirectional data interaction.

[0063] In one specific embodiment, when the device is powered on for the first time or the user completes the installation and configuration, the IoT communication unit reports building type information to the cloud platform. The building type information includes the wall structure type. In this embodiment, the cloud platform pre-stores parameter configuration packages corresponding to three types of building thermal inertia: lightweight walls, medium thermal inertia walls, and heavy walls. Each parameter configuration package includes parameters such as a first rate of change threshold, a second rate of change threshold, a thermal inertia calibration coefficient λ, a rate calibration coefficient μ, and a color temperature adjustment time constant τ. Based on the building type information, the cloud platform matches the corresponding parameter configuration package and pushes it to the IoT communication unit via MQTT downlink messages. The IoT communication unit then writes the parameters into the parameter storage area of ​​the local controller. Subsequently, the cloud platform can also remotely modify the above parameters by actively sending configuration update messages without replacing the hardware.

[0064] Understandably, the reason for centrally storing parameter configuration packages on a cloud platform and managing them according to building thermal inertia type is that different buildings have significant differences in the materials, thickness, and insulation performance of their building envelopes. This results in different reasonable value ranges for parameters such as thermal inertia calibration coefficients and rate of change thresholds depending on the building type. If these parameters are fixed in the local controller, the adjustment effect of the same hardware product will vary significantly in different building environments. Centralizing parameter maintenance in the cloud not only allows for automatic matching and adaptation of parameters based on the actual building conditions during equipment installation, but also enables continuous optimization and batch push of various parameter configuration packages after accumulating more user data. This ensures that the local control logic maintains continuous matching with the actual thermal inertia characteristics of the building without replacing the hardware.

[0065] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A lighting control system based on Internet of Things (IoT) indoor environment sensing, characterized in that, include: The main control layer sensing unit includes a first temperature sensor for collecting indoor temperature and a first illuminance sensor for collecting overall indoor illuminance. The correction layer sensing unit includes a second temperature sensor attached to the inner surface of the outer wall to collect the temperature of the inner surface of the outer wall and a second illuminance sensor to collect the illuminance at the window edge. A basic target determination unit is connected to the main control layer perception unit and the correction layer perception unit respectively, and is used to determine the basic color temperature value based on the indoor temperature and the basic brightness value based on the overall indoor illuminance. A thermal inertia correction unit is connected to the correction layer sensing unit and the basic target determination unit, respectively. It is used to determine the time shift factor and rate factor based on the temperature change rate of the inner surface of the outer wall, to perform time shift on the indoor temperature based on the time shift factor to obtain a virtual temperature, and to replace the indoor temperature with the virtual temperature and input it into the basic target determination unit to obtain the color temperature target value. A boundary constraint unit, which is connected to the correction layer sensing unit and the thermal inertia correction unit respectively, is used to constrain the effective values ​​of the time shift factor and the rate factor based on the comparison results of the window edge illuminance change rate with the first change rate threshold and the second change rate threshold respectively. An adjustment command generation unit is connected to the thermal inertia correction unit and the boundary constraint unit, respectively, to determine the color temperature adjustment rate based on the constrained rate factor, generate a color temperature adjustment command based on the color temperature target value and the color temperature adjustment rate, and generate a brightness adjustment command based on the brightness base value. The Internet of Things (IoT) communication unit is connected to the adjustment instruction generation unit to send the color temperature adjustment instruction and the brightness adjustment instruction to the lighting controller and to interact with the cloud platform to receive parameter configuration information. The cloud platform is connected to the IoT communication unit to store parameter configuration information and send the parameter configuration information to the IoT communication unit.

2. The lighting control system based on IoT indoor environment sensing according to claim 1, characterized in that, The thermal inertia correction unit determines the direction of the time shift factor based on the rate of change of the temperature of the inner surface of the exterior wall. If the rate of change of the temperature of the inner surface of the exterior wall is negative, the time shift factor causes the virtual temperature to lead the current indoor temperature, and the absolute value of the time shift factor is positively correlated with the absolute value of the rate of change of the temperature of the inner surface of the exterior wall. If the rate of change of the temperature on the inner surface of the exterior wall is positive, then the time-shifting factor causes the virtual temperature to lag behind the current indoor temperature.

3. The lighting control system based on IoT indoor environment sensing according to claim 2, characterized in that, The rate factor is negatively correlated with the absolute value of the rate of change of the temperature on the inner surface of the exterior wall.

4. The lighting control system based on IoT indoor environment sensing according to claim 1, characterized in that, The boundary constraint unit applies different constraints to the effective values ​​of the time-shift factor and the rate factor based on the interval to which the absolute value of the window edge illuminance change rate belongs, wherein the interval includes: The rapid change range in which the absolute value of the window edge illuminance change rate is greater than the first change rate threshold; The absolute value of the window edge illuminance change rate is greater than or equal to the second change rate threshold and less than or equal to the first change rate threshold in a gradual change range. Furthermore, the absolute value of the window edge illuminance change rate is less than the stable range of the second change rate threshold.

5. The lighting control system based on IoT indoor environment sensing according to claim 4, characterized in that, The boundary constraint unit, based on the judgment result that the absolute value of the window edge illuminance change rate is in the rapid change range, constrains the effective value of the rate factor to a preset minimum value, and keeps the effective value of the time shift factor at its corresponding calculated value; the boundary constraint unit, based on the judgment result that the absolute value of the window edge illuminance change rate is in the slow change range, keeps the effective value of the time shift factor at its corresponding calculated value, and keeps the effective value of the rate factor at its corresponding calculated value.

6. The lighting control system based on IoT indoor environment sensing according to claim 4, characterized in that, Based on the judgment result that the absolute value of the window edge illuminance change rate is within the stable interval, the boundary constraint unit sets the effective value of the time shift factor to zero and the effective value of the rate factor to a preset default value.

7. The lighting control system based on IoT indoor environment sensing according to claim 4, characterized in that, Based on the judgment result that the absolute value of the window edge illuminance change rate is within the rapid change range, the boundary constraint unit outputs a brightness maintenance constraint to the adjustment command generation unit, so that the brightness adjustment command generated by the adjustment command generation unit keeps the current brightness value unchanged and does not update with the change of the overall indoor illuminance.

8. The lighting control system based on IoT indoor environment sensing according to claim 7, characterized in that, The adjustment command generation unit determines the color temperature adjustment rate based on the difference between the target color temperature value and the current color temperature value, and the constrained rate factor. The color temperature adjustment rate is positively correlated with the difference between the target color temperature value and the current color temperature value, and also positively correlated with the constrained rate factor.

9. The lighting control system based on IoT indoor environment sensing according to claim 1, characterized in that, The base color temperature value determined by the base target determination unit is positively correlated with the indoor temperature; the base brightness value determined by the base target determination unit is negatively correlated with the overall indoor illuminance.

10. The lighting control system based on IoT indoor environment sensing according to claim 1, characterized in that, The parameter configuration information received by the IoT communication unit from the cloud platform includes the first rate of change threshold and the second rate of change threshold; The cloud platform stores parameter configuration packages corresponding to different building thermal inertia types, and sends the corresponding parameter configuration packages to the IoT communication unit based on the building type information.

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