Explore the innovative technology behind Luminous Photonics' horticultural lighting solutions, based on our Uniform Photon Flux Principle (UPFP) for modular LED arrays.
Our research has led to the development of the Uniform Photon Flux Principle (UPFP), a groundbreaking approach to optimizing Photosynthetic Photon Flux Density (PPFD) distribution in controlled-environment agriculture. The UPFP leverages a particular arrangement of Chip-on-Board (CoB) LED elements, positioned according to the centered square number integer sequence (Online Encyclopedia of Integer Sequences: A001844) pattern logic. By carefully assigning optimal intensities to each layer, as informed by our proprietary machine learning algorithm, we achieve unprecedented uniformity in PPFD across the growing area.
Key Benefits of the UPFP:
Below are graphical representations that demonstrate the effectiveness of employing the UPFP in our patented technology to achieve truly uniform light distribution. Each set of graphs compares a traditional or less optimized approach (right) with our UPFP-based solution (left).
These graphs illustrate the spatial distribution of light intensity, highlighting the "superfluous energy" outside the target PPFD range. The UPFP-based graph on the left demonstrates a more uniform beam spread with significantly reduced energy waste.
These 3D graphs illustrate the spatial distribution of PPFD, as presented in our research. The colors represent different intensity levels, with blue being low and red being high. The orange rectangle shows the target PPFD range. Note how the UPFP-based graph on the left exhibits a more uniform distribution with minimal "superfluous energy" (light outside the target PPFD range).
These graphs provide a top-down view of the PPFD distribution, highlighting the variance from the target PPFD. The UPFP-based approach (left) demonstrates significantly reduced variance in photon distribution, showcasing far superior uniformity.
Heatmaps offer another intuitive way to visualize PPFD distribution. Warmer colors (reds) represent higher PPFD, while cooler colors (blues) represent lower PPFD. The UPFP-based heatmap (left) displays a more consistent color across the growing area, signifying superior uniformity. While the competitor displays a pronounced concentration of photons toward the center of the illuminated area, as can be seen by the circular radiation pattern.
Central to our Uniform Photon Flux Principle (UPFP) is a sophisticated machine learning algorithm that dynamically optimizes LED intensities to ensure uniform Photosynthetic Photon Flux Density (PPFD) across the grow area. Below are key components of our algorithm:
The optimization function minimizes the Mean Absolute Deviation (MAD) of PPFD from the target value while adhering to energy constraints. Here's a snippet of how the objective function is defined:
def objective_function(light_intensities, target_ppfd):
ppfd_values = calculate_ppfd(light_intensities)
mad = np.mean(np.abs(ppfd_values - target_ppfd))
energy_consumption = np.sum(light_intensities)
return mad + 0.3 * energy_consumption
Explanation:
This function calculates the MAD between the current PPFD distribution and the target PPFD. It also considers the total energy consumption by summing up the light intensities. The objective is to minimize both MAD and energy usage while hitting the target PPFD, with energy consumption weighted by a factor of 0.3.
Light intensity at each measurement point is determined using the Lambertian emission model. This is appropriate as CoBs are near-perfect Lambertian emitters. Below is a snippet illustrating this calculation:
def lambertian_emission(intensity, distance, height):
if distance == 0:
return intensity
return (intensity * height) / ((distance ** 2 + height ** 2) ** 1.5)
Explanation:
This function computes the radiant intensity at a given point based on the distance from the light source and the height of the LED. It ensures that the intensity diminishes appropriately with distance, following the Lambertian emission characteristics.
We utilize the Sequential Least Squares Programming (SLSQP) method from SciPy to perform the optimization. Here's how the optimization is initiated:
result = minimize(
objective_function,
initial_intensities,
args=(target_ppfd,),
method='SLSQP',
bounds=bounds,
constraints=constraints
)
Explanation:
The `minimize` function seeks the optimal light intensities for each concentric square layer of CoBs in our patented solution's LED arrangement that reduce the MAD, while respecting predefined bounds and constraints. The SLSQP method efficiently handles both equality and inequality constraints, making it suitable for our optimization needs.
An integral component of our agentic AI platform, our algorithm continuously monitors environmental data from integrated sensors. Based on real-time feedback, it dynamically recalibrates LED intensities to maintain optimal PPFD levels, ensuring consistent plant growth conditions.
Explore our optimization process through an interactive simulation. Adjust parameters such as floor dimensions and perimeter reflectivity to see how our algorithm adapts LED intensities to maintain uniform PPFD.
Interactive simulation coming soon!
Our UPFP technology is based on rigorous mathematical modeling and optimization techniques. Here are some key technical aspects:
Lambertian Emission Model:We are committed to rigorous experimental validation of our UPFP technology. We will be using Apogee Instruments spectroradiometers (PS series for lab testing and the MS-100 handheld for field testing) to empirically verify the principle across the 380–1000 nm range. These measurements will enable us to:
Measure total photon flux and PPFD distribution across the plant canopy.
Corroborate our theoretical predictions with real-world data.
Further refine our models and optimization algorithms.
Zhang, G., et al., 2015. A combination of downward lighting and upward lighting improves plant growth in plant factories. Hortscience, 50(8), 1126--1130.
Joshi, J., Zhang, G., Shen, S., Supaibulwatana, K., Watanabe, C., Yamori, W., 2017. A combination of downward lighting and supplemental upward lighting improves plant growth in a closed plant factory with artificial lighting. Hortscience 52 (6), 831--835. https://doi.org/10.21273/HORTSCI11822-17
Kozai, T., 2022. Role and characteristics of PFALs. Plant Factory Basics, Applications and Advances, 46. Academic Press.
Runkle, E., 2021. Hidden benefits of supplemental lighting. Greenhouse Product News, 42. https://gpnmag.com/article/hidden-benefits-of-supplemental-lighting/