Real-Time Detection of Strawberry Ripeness Using Augmented Reality and Deep Learning

Sensors (Basel). 2023 Sep 3;23(17):7639. doi: 10.3390/s23177639.

Abstract

Currently, strawberry harvesting relies heavily on human labour and subjective assessments of ripeness, resulting in inconsistent post-harvest quality. Therefore, the aim of this work is to automate this process and provide a more accurate and efficient way of assessing ripeness. We explored a unique combination of YOLOv7 object detection and augmented reality technology to detect and visualise the ripeness of strawberries. Our results showed that the proposed YOLOv7 object detection model, which employed transfer learning, fine-tuning and multi-scale training, accurately identified the level of ripeness of each strawberry with an mAP of 0.89 and an F1 score of 0.92. The tiny models have an average detection time of 18 ms per frame at a resolution of 1280 × 720 using a high-performance computer, thereby enabling real-time detection in the field. Our findings distinctly establish the superior performance of YOLOv7 when compared to other cutting-edge methodologies. We also suggest using Microsoft HoloLens 2 to overlay predicted ripeness labels onto each strawberry in the real world, providing a visual representation of the ripeness level. Despite some challenges, this work highlights the potential of augmented reality to assist farmers in harvesting support, which could have significant implications for current agricultural practices.

Keywords: YOLOv7; augmented reality; deep learning; ripeness; strawberry.

MeSH terms

  • Agriculture
  • Augmented Reality*
  • Deep Learning*
  • Female
  • Fragaria*
  • Humans
  • Labor, Obstetric*
  • Pregnancy

Grants and funding

This work was conducted with the financial support of the Science Foundation Ireland Centre for Research Training in Digitally Enhanced Reality (d-real) under Grant No. 18/CRT/6224. The authors would like to express their gratitude to Michael Gaffney and Ester Ferrari for generously allowing the test trials to be conducted in the Teagasc strawberry greenhouse and for their valuable assistance.