Plant-friendly night lighting system and method

Abstract

According to the plant-friendly night illumination system and method, in system setting, through cooperation of a liquid crystal lens module and a projection optical module, different shape changes of an illumination area are achieved, the illumination angle and intensity are adjusted for plants which are not resistant to light, interference of light pollution to the plants is fundamentally reduced, and the illumination effect of the plants is improved. The proportion of warm white light, green light and far-red light is accurately and dynamically adjusted, spectral distribution is optimized according to plant varieties, environmental conditions and time periods, the ecological adaptability of illumination is further improved, and the influence of night illumination pollution on the physiological rhythm and growth mode of garden plants is avoided or reduced.

Description

Technical Field

[0001] The present invention belongs to the field of plant light pollution prevention and control, and particularly relates to a plant-friendly night lighting system and method. Background Art

[0002] In recent years, the problem of night light pollution has become increasingly serious globally, having a significant impact on the plant ecosystem. Night light pollution interferes with the growth and development, phenological characteristics, and community composition of plants, and may even exacerbate the invasion of alien plants into native communities. The widespread application of urban nightscape lighting has made the problem of light pollution particularly prominent. Nighttime light pollution may promote the invasion of alien plants and intensify the competitive exclusion of common species from rare species within native communities. In addition, night light pollution has a negative impact on native species in forest and wetland ecosystems, resulting in a decline in species diversity and a change in community structure.

[0003] The harm of night light pollution to plants is mainly reflected in interfering with their physiological rhythms, changing growth patterns, and affecting the interaction between plants and insects. The physiological rhythms of plants rely on natural photoperiod regulation. For example, deciduous tree species rely on the changes between day and night to determine the timing of winter in autumn and winter, while night light pollution disrupts this regulatory mechanism. Under strong artificial lighting environments, deciduous tree species such as ginkgo and maple may delay leaf shedding because they cannot perceive the temperature difference between day and night and the short-day signal, and may even keep their leaves until winter, resulting in their failure to fully enter the dormant period. Trees in such environments for a long time may have a weakened growth potential in the following spring due to their inability to reduce metabolism in winter, and may even die due to accumulated damage over several consecutive years. In addition, long-term exposure to artificial light sources can also cause plants to maintain a relatively high photosynthesis level, leading to too rapid consumption of their carbon reserves, thereby reducing their stress resistance and increasing the risk of disease occurrence.

[0004] Currently, for the impact of night light pollution on plants, the main solutions include adjusting the lighting time and reducing the lighting intensity. Traditional methods such as restricting the lighting time and intensity at night, although reducing light pollution to a certain extent, may affect the convenience of human activities. Therefore, the main research direction is to study how to minimize the negative impact on plants while meeting the lighting needs of humans. Summary of the Invention

[0005] The purpose of the present invention is to provide a plant-friendly night lighting system and method to avoid or reduce the impact of night light pollution on the physiological rhythms and growth patterns of garden plants.

[0006] To achieve the above object, the technical solution of the present invention is as follows:

[0007] A plant-friendly night lighting system, comprising: a light source module, a liquid crystal lens module, a projection optical module, a control module, and a monitoring and feedback module;

[0008] The light source module includes a heat dissipation substrate, a composite LED array and a light homogenizing plate disposed on the heat dissipation substrate. Among them, the proportion of warm white lamps with a color temperature of 3000K - 3500K, green lamps with a wavelength of 500 - 570nm and LED far red lamps with a wavelength of 700 - 750nm in the composite LED array is 40 - 60%, 20 - 30%, and 20 - 30% respectively; the light emitted by the composite LED array is emitted through the light homogenizing plate, the liquid crystal lens module and the projection optical module;

[0009] The liquid crystal lens module sequentially includes an upper polarizer, a four - quadrant indium tin oxide ITO electrode layer, a liquid crystal layer, a common electrode layer and a lower polarizer from top to bottom. The four - quadrant indium tin oxide ITO electrode layer includes four independent control regions: upper, lower, left and right;

[0010] The projection optical module sequentially includes a Fresnel condenser lens and a focus - adjustable lens group. A positioning pin is provided between the Fresnel condenser lens and the liquid crystal lens module to ensure that the coaxiality error < 0.05mm;

[0011] The control module includes a micro - control unit MCU, a high - voltage driving unit, a wireless communication unit and a human - machine interaction interface HMI touch screen; the four independent control regions of the upper, lower, left and right in the four - quadrant indium tin oxide ITO electrode layer are respectively connected to the high - voltage driving unit through leads, and the voltages of different regions are respectively controlled through the micro - control unit MCU and the high - voltage driving unit to independently adjust the refractive index of the liquid crystal in each quadrant;

[0012] The monitoring and feedback module includes a photosensitive sensor, a passive infrared sensor PIR sensor and a feedback circuit, which is used to monitor the shape of the projection light spot in real time and adjust the four - quadrant voltage in a closed - loop manner.

[0013] Preferably, the heat dissipation substrate is a copper substrate, which is connected to the heat dissipation fins through a heat pipe, and a turbine fan is laterally installed to form a forced air cooling channel.

[0014] Preferably, a thermal grease layer is filled between the heat dissipation substrate and the composite LED array to ensure that the flatness error < 0.05mm.

[0015] Preferably, a toothed ring is provided on the outer edge of the upper polarizer, which is meshed with a micro - motor through a worm to realize the rotation adjustment of the polarizer angle by ± 30°.

[0016] Preferably, the focus - adjustable lens group of the projection optical system is driven by a stepping motor. The stepping motor and the lens barrel are connected through a helical gear. The gear module is 1 - 0.5mm, and the lead is 0.5 - 1mm, realizing a stepping displacement accuracy of 0.01 - 0.02mm; the focus - adjustable lens group is fixed through a linear slide rail, and the straightness error of the slide rail is less than 0.02mm / m.

[0017] Preferably, the microcontroller unit MCU supports the output of 8-bit Pulse Width Modulation (PWM) signals, with a driving voltage range of 0 - 5V and a response time < 10ms. The microcontroller unit MCU is responsible for short-term pedestrian flow prediction and real-time regulation to avoid the impact of network latency on the experience. Among them, the wireless communication unit LoRa / Zigbee / Wi-Fi / 5G supports remote control and macro parameter adjustment. The Human-Machine Interface (HMI) touch screen supports local parameter setting and fault diagnosis. The parameters that can be set through human-machine interaction are as follows in the table:

[0018]

[0019] A plant-friendly night lighting method

[0020] From 18:00 to 22:00, 80% - 100% of the warm white lights in the composite LED arrays on the main garden road are on, and the rest are off; 80% - 100% of the green lights in the composite LED arrays in the plant area are on, and the rest are off; 80% - 100% of the far-infrared lights in the composite LED arrays in the lake / water feature area are on, and the rest are off; 40% - 60% of the warm white lights, 10% - 30% of the green lights, and 10% - 30% of the far-infrared lights in the composite LED arrays on the paths / rest areas are on, and the rest are off;

[0021] From 22:00 to 00:00, 40% - 60% of the warm white lights and 10% - 30% of the far-infrared lights in the composite LED arrays on the main garden road are on, and the rest are off. When triggered by PIR induction, it is adjusted to 80% - 100% of the warm white lights and 10% - 30% of the far-infrared lights on, and the rest are off; 40% - 60% of the green lights in the composite LED arrays in the plant area are on, and the rest are off; 40% - 60% of the far-infrared lights in the composite LED arrays in the lake / water feature area are on, and the rest are off; 20% - 40% of the far-infrared lights in the composite LED arrays on the paths / rest areas are on, and the rest are off. When triggered by PIR induction, it is adjusted to 40% - 60% of the warm white lights and 20% - 40% of the far-infrared lights on, and the rest are off;

[0022] From 00:00 to 05:00, 10% - 30% of the warm white lights and 40% - 60% of the far-infrared lights in the composite LED arrays on the main garden road are on, and the rest are off. When triggered by PIR induction, it is adjusted to 60% of the warm white lights and 40% - 60% of the far-infrared lights on, and the rest are off; 10% - 15% of the green lights in the composite LED arrays in the plant area are on, and the rest are off; 10% - 15% of the far-infrared lights in the composite LED arrays in the lake / water feature area are on, and the rest are off; 10% - 15% of the far-infrared lights in the composite LED arrays on the paths / rest areas are on, and the rest are off. When triggered by PIR induction, it is adjusted to 40% - 60% of the warm white lights and 10% - 15% of the far-infrared lights on, and the rest are off;

[0023] From 05:00 to 07:00, 40%-60% of the warm white lights and 0%-30% of the far red lights in the composite LED arrays on the main garden road are on, and the rest of the lights are off. When triggered by PIR induction, it is adjusted to 80%-100% of the warm white lights and 10%-30% of the far red lights on, and the rest of the lights are off; 20%-40% of the green lights in the composite LED arrays in the plant area are on, and the rest of the lights are off; 20%-40% of the far infrared lights in the composite LED arrays in the lake / water feature area are on, and the rest of the lights are off; 10%-30% of the green lights and 10%-30% of the far red lights in the composite LED arrays on the path / rest area are on, and the rest of the lights are off. When triggered by PIR induction, it is adjusted to 40%-60% of the warm white lights, 10%-30% of the green lights and 10%-30% of the far red lights on, and the rest of the lights are off;

[0024] During other time periods, all the lights are off.

[0025] Furthermore, according to the specific road surface conditions, by adjusting the voltages of the four independent control regions of the four-quadrant indium tin oxide ITO electrode layer, including the upper, lower, left, and right regions, the refractive index of different regions is adjusted to convert the emitted illumination area between circular, elliptical, rectangular, and asymmetric shapes. For light-intolerant landscape trees and hedges at asymmetric points, the projection pattern can be adjusted to avoid direct irradiation of plants. The projection size is 2-5m, and the aspect ratio is 1:1-1:4.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] First of all, at the mechanical design level, the present invention adopts liquid crystal lens adjustment technology. The liquid crystal lens module is independently controlled by a four-quadrant indium tin oxide ITO electrode layer. The voltage of each region can be precisely adjusted to adjust the refractive index of the liquid crystal. The flexible circuit board (FPC) interface is used to achieve flexible configuration of the electrode leads, with strict precision requirements, and the line width error is only ±10%. In addition, the rotation adjustment angle of the polarizer reaches ±30°. The Fresnel condenser lens and the adjustable focus lens group are driven by a stepper motor, and the precision can reach 0.01-0.02mm per step displacement. These designs achieve precise control of the shape, size, and distribution of the light spot, and ultimately achieve dynamic adjustment of the illumination area. Traditional lighting methods often use fixed light sources and uniform projection modes, which are likely to cause light-intolerant plants to be over-irradiated, thus affecting their growth and physiological rhythms. The present invention intelligently adjusts the shape of the light spot, enables the illumination area to switch between circular, elliptical, rectangular, and asymmetric shapes, and adjusts the illumination angle and intensity for light-intolerant plants, fundamentally reducing the interference of light pollution on plants. For example, in a forest or wetland environment, this system can avoid direct strong light irradiation on deciduous tree species, ensure that they can enter the normal winter dormancy state, and prevent weakness or death in the following year due to overgrowth.

[0028] The refractive index of the liquid crystal lens can be varied in different directions by applying an external voltage. In the system design, a four-quadrant ITO electrode is used to control the liquid crystal layer, which means that the light refraction in each direction (up, down, left, right) can be controlled individually. Circular spot (symmetric): The same voltage is applied to all four quadrant electrodes; the refractive index of the liquid crystal layer is uniform → the light is focused evenly; the output is a standard circular spot. Elliptical spot: The voltage of the upper and lower electrodes ≠ the voltage of the left and right electrodes; longitudinal or transverse flattening focusing is achieved; the output is an elliptical spot (the minor axis is perpendicular to the direction with the higher voltage). Rectangular spot: By applying a gradient voltage or a non-linear voltage to the four quadrants; controlling the focal length to diverge differently in the X and Y directions; combined with the light boundary enhancement of the Fresnel lens system, a spot close to the rectangular boundary can be achieved. Asymmetric patterns (such as semi-circle, triangle, offset ellipse), only some quadrants are energized, or the energization is uneven; for example, only the upper and right quadrants are pressurized, and a downward offset or polarized pattern can be formed.

[0029] The light source module combines a composite LED array with a heat dissipation substrate, and is connected to the heat dissipation fins through a copper substrate and a heat pipe, and cooperates with a turbo fan to form a forced air cooling channel, significantly improving the heat dissipation efficiency, ensuring long-term efficient operation, and avoiding overheating of the LED array. The filling of the thermal grease layer ensures effective heat conduction, and the flatness error is less than 0.05 mm, optimizing the heat dissipation performance.

[0030] The monitoring and feedback module monitors the shape of the projection spot in real time through a photosensitive sensor, and can adjust the four-quadrant voltage according to the feedback to form a closed-loop regulation. This function can ensure the precise adjustment of the projection spot and avoid the influence of light leakage on plant growth.

[0031] Secondly, in terms of lighting configuration, the present invention precisely and dynamically adjusts the proportions of warm white light, green light, and far-red light, optimizes the spectral distribution according to plant species, environmental conditions, and time periods, and further enhances the ecological adaptability of lighting. For example, the intensity of green light can be appropriately reduced at night to minimize the interference with the plant's photoperiod, while the proportion of far-red light can be increased in the early morning mode to promote the plant's response to the morning light signal. Warm white light provides the necessary support for photosynthesis during peak periods and creates a comfortable lighting environment during periods with more human activities; far-red light helps ensure the normal operation of the night monitoring system at a relatively low light intensity at night and late at night, while avoiding excessive stimulation of plants. Green light is mainly provided in the plant area, which can enhance the light tolerance of plants, avoid unnecessary light interference, and reduce physiological interference with plants. By adjusting the light intensity through a PIR sensor, the system can intelligently and automatically adjust the light source according to different scenarios and time periods, meeting the growth needs of plants while protecting them from light pollution and ensuring their biological rhythms and healthy growth. Moreover, the present invention integrates a real-time monitoring and feedback control system, which can optimize the lighting scheme in combination with photosensitive sensors and temperature and humidity sensors. Traditional plant-friendly lighting mostly uses a fixed proportion of light source combinations, but different plant species have significant differences in their light requirements, and environmental factors also affect the photosynthesis requirements of plants.

[0032] Finally, the present invention has more advantages than traditional technologies in terms of energy efficiency management and remote control. The system supports PIR induction triggering, crowd flow prediction, and LoRa / Zigbee / Wi-Fi / 5G remote control, and can dynamically adjust the light intensity and mode while ensuring lighting requirements, avoiding unnecessary energy consumption. Compared with existing fixed-time lighting systems, this system can adaptively adjust the lighting power according to actual usage. For example, during periods with low pedestrian flow, the intensity of warm white light can be reduced, and only far-red light is retained to maintain the visibility of the night security monitoring system while reducing energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 System diagram of the present invention;

[0034] Figure 2 Comparison chart of the flowering periods of different plants in the experimental group and the control group;

[0035] Figure 3 Comparison chart of the average number of fallen leaves per single plant of plants in the experimental group and the control group;

[0036] Figure 4 Comparison chart of the malondialdehyde content in different plants in the experimental group and the control group;

[0037] Figure 5 Comparison chart of the soluble sugar content in different plants in the experimental group and the control group;

[0038] Figure 6 Control chart of soluble protein content in different plants in the experimental group and the control group. Detailed implementation method

[0039] The present invention will be further described below in conjunction with embodiments and drawings.

[0040] Embodiment 1: Green space application experiment

[0041] To avoid the influence of terrain factors on the test results, lighting equipment is installed on the footpath with consistent terrain conditions in the study area. Hydrangea and Rhododendron pulchrum are planted on both sides of the road.

[0042] One control group and two experimental groups are set up in the sample plot. There is no night lighting in Control Group 1.

[0043] In Experimental Group 1, the minimum working power of the lighting system of the present invention is 10W, and the maximum working power is 250W. The lighting area is adjusted to a rectangular area with the same width as the road surface.

[0044] The width of the footpath in the study area is 2m. To achieve precise control of the target light spot size (2m wide × 5m long), the installation height of the lamp is 5m (vertical projection). At this height, through the independent adjustment of the four-quadrant liquid crystal lens, the divergence angle is set to 22.6° (corresponding to the driving voltage of 2.8V and the PWM duty cycle of 143 / 255) in the horizontal direction (left and right quadrants), and the divergence angle is set to 53.1° (voltage of 4.5V and the PWM duty cycle of 229 / 255) in the vertical direction (upper and lower quadrants), and a rectangular light spot of 2m × 5m can be precisely formed.

[0045] Lighting settings: From 18:00 to 22:00, 100% warm white lights in the composite LED array on the main garden road are on, and the rest are off; 100% green lights in the composite LED array in the plant area are on, and the rest are off; 100% far-infrared lights in the composite LED array in the lake / water feature area are on, and the rest are off; in the composite LED array in the path / rest area, 50% warm white lights, 20% green lights, and 20% far-infrared lights are on, and the rest are off.

[0046] From 22:00 to 00:00, 50% warm white lights and 20% far-infrared lights in the composite LED array on the main garden road are on, and the rest are off. When triggered by PIR induction, it is adjusted to 100% warm white lights and 20% far-infrared lights on, and the rest are off; 50% green lights in the composite LED array in the plant area are on, and the rest are off; 50% far-infrared lights in the composite LED array in the lake / water feature area are on, and the rest are off; 30% far-infrared lights in the composite LED array in the path / rest area are on, and the rest are off. When triggered by PIR induction, it is adjusted to 50% warm white lights and 30% far-infrared lights on, and the rest are off.

[0047] From 00:00 to 05:00, 20% of the warm white lights and 50% of the far red lights in the composite LED arrays on the main garden path are on, and the rest are off. When triggered by PIR induction, it is adjusted to 60% warm white lights and 50% far red lights on, and the rest are off; 10% of the green lights in the composite LED arrays in the plant area are on, and the rest are off; 10% of the far infrared lights in the composite LED arrays in the lake / water feature area are on, and the rest are off; 10% of the far red lights in the composite LED arrays in the path / rest area are on, and the rest are off. When triggered by PIR induction, it is adjusted to 50% warm white lights and 10% far red lights on, and the rest are off;

[0048] From 05:00 to 07:00, 50% of the warm white lights and 20% of the far red lights in the composite LED arrays on the main garden path are on, and the rest are off. When triggered by PIR induction, it is adjusted to 100% warm white lights and 20% far red lights on, and the rest are off; 30% of the green lights in the composite LED arrays in the plant area are on, and the rest are off; 30% of the far infrared lights in the composite LED arrays in the lake / water feature area are on, and the rest are off; 20% of the green lights and 20% of the far red lights in the composite LED arrays in the path / rest area are on, and the rest are off. When triggered by PIR induction, it is adjusted to 50% warm white lights, 20% green lights and 20% far red lights on, and the rest are off;

[0049] During other time periods, all the lights are off.

[0050] The experimental group 2 uses traditional 250W high-pressure sodium lamps.

[0051] The measurement indicators include three parts:

[0052] (1) The light experiment is carried out from March until the end of the flowering period in Experiment 5. From March to July, the initial flowering period (the time from the blooming of the first flower to the time when the opened flowers account for 25%), the full-bloom period (the time when more than half of the flower buds on the plant fully unfold their petals), the final flowering period (the time when the flowers with fallen petals account for more than 95%) of 2 kinds of plants are recorded, and the number of blooming flowers and the total number of flowers are recorded every three days.

[0053] (2) Since Hydrangea macrophylla is a winter deciduous plant in the Shanghai area while Rhododendron pulchrum is evergreen, only the number of leaves of Hydrangea macrophylla is recorded every three days starting from October, and the survival number is counted in March of the following year;

[0054] (3) In April, the malondialdehyde, soluble sugar, and soluble protein of the plant leaves are measured. The experimental results of the flowering period are as Figure 1 shown.

[0055] From Figure 1It can be seen that compared with the control group, experimental group 1 (the patented lighting system) extended the flowering period of hydrangea and azalea by 3 days and 6 days respectively, and the peak flowering period was extended by 18 and 12 days respectively. Experimental group 2 (traditional high-pressure sodium lamps) shortened the flowering period of hydrangea and azalea by 12 days and 9 days respectively. Overall, the patented low-impact lighting system at night not only did not shorten the flowering period, but on the contrary had a certain effect of extending the flowering period, while the traditional high-intensity light greatly shortened the flowering period.

[0056] Hydrangeas and Rhododendron splendidum are both considered short-day plants. Some short-day plants may extend their flowering period if the light intensity is low at night. This is because this interruption will make the plant "mistakenly believe" that the daytime is longer, thus delaying the onset of flowering. High-intensity night light can disrupt the plant's circadian rhythm, causing the plant to enter a dormant state too early or miss the best time to bloom. Such lighting conditions may cause the flowering time to be earlier or the flowering period to be shortened. Too much night light may cause the plant's physiological cycle to end prematurely, thereby causing the flowering period to be earlier or shorter.

[0057] Figure 2 The bar graph shows the statistical data of leaf fall and survival rate.

[0058] The experimental results showed that the trends of experimental group 1 and the control group were basically the same, the peak of leaf fall was basically concentrated in November and December, and the survival rate in the second year was not much different. However, the number of fallen leaves in the experimental group in November was significantly less than that in the control group and experimental group 1, the peak of leaf fall was postponed and concentrated in December, and the survival rate in the second year was lower than that in the control group and the experimental group. Hydrangea is a typical short-day plant, and its leaf shedding is closely related to the photoperiod. In the natural environment, when the daylight hours are shortened and the night time is prolonged in autumn, the plant will experience flower bud differentiation and leaf senescence and enter a dormant state. Nighttime light, especially too strong artificial light, may prolong its physiological active period and delay leaf shedding. In addition, too strong nighttime lighting will cause the plant to fail to enter a dormant state in time, which may affect the plant's tolerance to cold. Plants usually need to enter a dormant period to store energy and cope with the cold winter. Plants that have not entered a completely dormant state may suffer frost damage or excessive nutrient consumption in winter, affecting their growth and survival rate in the coming year.

[0059] Figure 3 , Figure 4 and Figure 5 The following are schematic diagrams of the malondialdehyde, soluble sugar, and soluble protein content in different plants in the experimental group and the control group, respectively. As can be seen from the figure, compared with the control group, the malondialdehyde and soluble sugar of the hydrangea and Rhododendron splendidum experimental group 1 increased slightly, and the soluble protein decreased slightly. Compared with the control group, the malondialdehyde and soluble sugar of the hydrangea and Rhododendron splendidum experimental groups increased significantly, and the soluble protein decreased significantly.

[0060] It is shown that night-time lighting can significantly affect the physiological metabolism of plants, especially the indicators related to stress response, energy metabolism, and protein synthesis. Among them, malondialdehyde reflects the degree of oxidative damage in plants. Night-time lighting disrupts the biological clock, causing abnormal photosynthetic metabolism, enhancing photo-oxidative stress, and leading to a large accumulation of reactive oxygen species (ROS), which triggers membrane lipid peroxidation.

[0061] Soluble sugar is the main osmotic adjustment substance in plants. Continuous photosynthesis occurs at night, while respiration at night is inhibited, resulting in sugar accumulation. Soluble protein is closely related to the metabolic activity of plants. Due to photo-oxidative stress, protein degradation is accelerated, and at the same time, photoperiod interference may reduce the synthesis of certain structural proteins and metabolic enzymes.

[0062] In summary, compared with the control group, Experimental Group 1 had less impact on the flowering period, growth cycle, and physiological indicators of Hydrangea macrophylla and Rhododendron pulchrum, while Experimental Group 2 had a significant impact.

Claims

1. A plant-friendly night lighting system, characterized in that, Including: A light source module, a liquid crystal lens module, a projection optical module, a control module, and a monitoring and feedback module; The light source module includes a heat dissipation substrate, a composite LED array, and a light homogenizing plate disposed on the heat dissipation substrate; among them, the proportion of warm white lights with a color temperature of 3000K - 3500K, green lights with a wavelength of 500 - 570nm, and LED far red lights with a wavelength of 700 - 750nm in the composite LED array are 40 - 60%, 20 - 30%, and 20 - 30% respectively; the light emitted by the composite LED array passes through the light homogenizing plate, the liquid crystal lens module, and the projection optical module and is emitted; The liquid crystal lens module includes, from top to bottom, an upper polarizer, a four - quadrant indium tin oxide ITO electrode layer, a liquid crystal layer, a common electrode layer, and a lower polarizer. The four - quadrant indium tin oxide ITO electrode layer includes four independent control regions: upper, lower, left, and right; The projection optical module sequentially includes a Fresnel condenser lens and a focus - adjustable lens group. A positioning pin is provided between the Fresnel condenser lens and the liquid crystal lens module to ensure that the coaxiality error < 0.05mm; The control module includes a micro - control unit MCU, a high - voltage driving unit, a wireless communication unit, and a human - machine interface HMI touch screen; the four independent control regions of the upper, lower, left, and right in the four - quadrant indium tin oxide ITO electrode layer are respectively connected to the high - voltage driving unit through leads. The voltages of different regions are respectively controlled through the micro - control unit MCU and the high - voltage driving unit to independently adjust the liquid crystal refractive index of each quadrant; The monitoring and feedback module includes a photosensitive sensor, a passive infrared sensor PIR sensor, and a feedback circuit, which is used to monitor the shape of the projection light spot in real time and adjust the four - quadrant voltage in a closed - loop manner.

2. The plant-friendly night lighting system according to claim 1, characterized in that, The heat dissipation substrate is a copper - made substrate, which is connected to the heat dissipation fins through a heat pipe, and a turbine fan is laterally installed to form a forced air - cooling channel.

3. The plant-friendly night lighting system according to claim 1, characterized in that, A thermal conductive silicone grease layer is filled between the heat dissipation substrate and the composite LED array to ensure that the flatness error < 0.05mm.

4. The plant-friendly night lighting system according to claim 1, wherein A toothed ring is provided on the outer edge of the upper polarizer, which is meshed with a micro - motor through a worm to realize the rotation adjustment of the polarizer angle by ± 30°; 5. The plant-friendly night lighting system according to claim 1, characterized in that, The focus - adjustable lens group of the projection optical system is driven by a stepping motor. The stepping motor is connected to the lens barrel through a helical gear. The gear module is 1 - 0.5mm, and the lead is 0.5 - 1mm, realizing a displacement accuracy of 0.01 - 0.02mm per step; the focus - adjustable lens group is fixed through a linear slide rail, and the straightness error of the slide rail < 0.02mm / m.

6. The plant-friendly night lighting system according to claim 1, characterized in that, The micro - control unit MCU supports the output of 8 - bit pulse - width modulation PWM signals, the driving voltage range is 0 - 5V, and the response time < 10ms. The micro - control unit MCU is responsible for short - term human flow prediction and real - time regulation to avoid the influence of network delay on the experience; among them, the wireless communication unit LoRa / Zigbee / Wi - Fi / 5G supports remote control and macro - parameter adjustment; the human - machine interface HMI touch screen supports local parameter setting and fault diagnosis. The parameters that can be set by human - machine interaction are as follows in the table:

7. A plant-friendly night lighting method, characterized in that, Using the system according to any one of claims 1 to 6, the specific steps include: From 18:00 to 22:00, 80%-100% of the warm white lights in the composite LED arrays on the main garden path are on, and the rest are off; 80%-100% of the green lights in the composite LED arrays in the plant area are on, and the rest are off; 80%-100% of the far-infrared lights in the composite LED arrays in the lake / water feature area are on, and the rest are off; 40%-60% of the warm white lights, 10%-30% of the green lights and 10%-30% of the far-infrared lights in the composite LED arrays in the path / rest area are on, and the rest are off. From 22:00 to 00:00, 40%-60% of the warm white lights and 10%-30% of the far-infrared lights in the composite LED arrays on the main garden path are on, and the rest are off. When triggered by PIR induction, it is adjusted to 80%-100% of the warm white lights and 10%-30% of the far-infrared lights on, and the rest are off; 40%-60% of the green lights in the composite LED arrays in the plant area are on, and the rest are off; 40%-60% of the far-infrared lights in the composite LED arrays in the lake / water feature area are on, and the rest are off; 20%-40% of the far-infrared lights in the composite LED arrays in the path / rest area are on, and the rest are off. When triggered by PIR induction, it is adjusted to 40%-60% of the warm white lights and 20%-40% of the far-infrared lights on, and the rest are off. From 00:00 to 05:00, 10%-30% of the warm white lights and 40%-60% of the far-infrared lights in the composite LED arrays on the main garden path are on, and the rest are off. When triggered by PIR induction, it is adjusted to 60% of the warm white lights and 40%-60% of the far-infrared lights on, and the rest are off; 10%-15% of the green lights in the composite LED arrays in the plant area are on, and the rest are off; 10%-15% of the far-infrared lights in the composite LED arrays in the lake / water feature area are on, and the rest are off; 10%-15% of the far-infrared lights in the composite LED arrays in the path / rest area are on, and the rest are off. When triggered by PIR induction, it is adjusted to 40%-60% of the warm white lights and 10%-15% of the far-infrared lights on, and the rest are off. From 05:00 to 07:00, 40%-60% of the warm white lights and 0%-30% of the far-infrared lights in the composite LED arrays on the main garden path are on, and the rest are off. When triggered by PIR induction, it is adjusted to 80%-100% of the warm white lights and 10%-30% of the far-infrared lights on, and the rest are off; 20%-40% of the green lights in the composite LED arrays in the plant area are on, and the rest are off; 20%-40% of the far-infrared lights in the composite LED arrays in the lake / water feature area are on, and the rest are off; 10%-30% of the green lights and 10%-30% of the far-infrared lights in the composite LED arrays in the path / rest area are on, and the rest are off. When triggered by PIR induction, it is adjusted to 40%-60% of the warm white lights, 10%-30% of the green lights and 10%-30% of the far-infrared lights on, and the rest are off. During other time periods, all the lights are off.

8. The method according to claim 7, wherein According to the specific road surface conditions, by adjusting the voltages of the upper, lower, left, and right four independent control regions of the four-quadrant indium tin oxide (ITO) electrode layer, the refractive index of different regions is adjusted to convert the emitted illumination area among circular, oval, rectangular, and asymmetric patterns. For light-sensitive landscape trees and hedges at asymmetric points, the projection pattern can be adjusted to avoid direct irradiation of plants. The projection size is 2 - 5 m, and the aspect ratio is 1:1 - 1:4.

Images