农作物病害是威胁农作物生长的主要因素之一, 机器学习算法能高效率实现大范围农作物病害的发现, 有利于对其进行及时处理, 进而提升农作物的产量和质量. 在大范围农业场景中, 由于供电等条件限制, 无法满足服务器等高算力设备的供电需求, 现有深度网络模型大多需要较高算力, 难以部署在低功耗的嵌入式设备上, 给大范围农作物病害的准确识别应用带来障碍. 为解决此问题, 提出了一种基于知识蒸馏的轻量化农作物病害识别模型, 并设计了一种基于残差结构和注意力机制的学生模型, 利用知识蒸馏方法从大规模模型ConvNeXt中迁移学习成果, 在实现模型轻量化的同时保持高精度识别. 实验结果表明, 在模型规模为2.28 MB的条件下, 39类农作物病害图像分类任务的准确率达到了98.72%, 且每类病害的精确率、召回率和特异度均高于90%. 该模型满足了在嵌入式设备中部署的需求, 为农作物病害识别提供了一种实用高效的解决方法.

Crop diseases are one of the main factors threatening crop growth. In this regard, machine-learning algorithms can efficiently detect large-scale crop diseases and are beneficial for timely processing and improving crop yield and quality. In large-scale agricultural scenarios, owing to limitations in power supply and other conditions, the power-supply requirements of high-computing-power devices such as servers cannot be fulfilled. Most existing deep-network models require high computing power and cannot be deployed easily on low-power embedded devices, thus hindering the accurate identification and application of large-scale crop diseases. Hence, this paper proposes a lightweight crop-disease-recognition algorithm based on knowledge distillation. A student model based on a residual structure and the attention mechanism is designed and knowledge distillation is applied to complete transfer learning from the ConvNeXt model, thus achieving the lightweight model while maintaining high-precision recognition. The experimental results show that the accuracy of image classification for 39 types of crop diseases is 98.72% under a model size of 2.28 MB, which satisfies the requirement for deployment in embedded devices and indicates a practical and efficient solution for crop-disease recognition.