Intelligent Frost Prediction and Active Protection Cyber-physical Systems in the Agricultural Sector

Publication Type:
Thesis
Issue Date:
2023
Full metadata record
Frost damage in broadacre cropping and horticulture (including viticulture) results in substantial economic losses to producers and may also disrupt associated product value chains. Frost risk windows are changing in timing, frequency, and duration. Faced with the increasing cost of mitigation infrastructure and competition for resources (e.g., water and energy), multi-peril insurance, and the need for supply chain certainty, producers are under pressure to innovate in order to manage and mitigate risk. Frost protection systems are cyber-physical systems comprising sensors (event detection), intelligence (prediction), and actuators (active protection methods). These systems are an important tool and cost factor in fighting against frost. Therefore, there is a need to improve the efficiency and effectiveness of frost protection cyber-physical systems. This study adopts the Internet of Things 2.0 architectures and emphasizes the dimensions of machine learning intelligence, scalability, interoperability, and user-friendliness in frost protection systems. This research also improves on the limitations of existing frost protection systems and the prediction methods that control the systems. The limitations are historical data dependence, low prediction temporal resolution, non-real-time response, and low fault tolerance. In response to the limitations of low prediction temporal resolution and non-real-time response, the existing 12-24 hours prediction methods are extended by artificial neural networks and recurrent neural networks for near real-time frost prediction. A minute-wise regression model to predict the next hour minimum temperature is proposed. The minute-wise model further highlights the system dependence on local historical data and sensors. To decouple this dependence, a spatial interpolation-based frost prediction system is implemented. This model-based system only requires data from existing weather stations to predict frost at any new sites. Combining the results of the previous two models, a cyber-physical system framework is proposed to improve the system fault tolerance. This framework is a modular design with the local data-based system as the primary predictor and the model-based system as both a secondary predictor and system stopping mechanism. The result shows improvements in operational cost compared to traditional methods. The final contribution is the improvement of energy efficiency on edge-based prediction. A spatially generalized model with a smaller prediction window is constructed and deployed on a LoRa transmission node. The proposed system not only improves energy efficiency, it also reduces the false positive rate.
Please use this identifier to cite or link to this item: