Challenges and Opportunities for Autonomous Micro-UAVs in Precision Agriculture

Abstract

Mobile robots such as unmanned ground vehicles (UGVs) and unmanned aerial vehicles (UAVs) are increasingly used for precision agriculture. While UGVs have larger payload capabilities and longer operation time, they are limited to 2-D space. This makes UAVs better suited for tasks that require fast coverage, harsh terrain traversal, and high altitude or multilevel operation. However, it remains a challenging task to develop a reliable yet fully autonomous UAV system that can actively extract actionable information in large-scale cluttered agricultural environments. Such a system will have to estimate its own poses, build a map of the environment, navigate through obstacles, and act to gather information with limited onboard computation and battery life. In this survey, we first review recent advances in UAV hardware and software, ranging from novel platforms and sensors to state-of-the-art autonomous navigation, object detection and segmentation, robot localization, and mapping algorithms related to agriculture. We then provide a list of challenges in each field and potential opportunities for the broader adoption of UAVs in precision agriculture.

Smallholder oil palm plantation sustainability assessment using multi-criteria analysis and unmanned aerial vehicles

“…Whilst UAV remote sensing is considered the future of precision agriculture (Aslan et al, 2022 ; Chong et al, 2017 ; Liu et al, 2022 ), there are a number of challenges which could be addressed through future research. Firstly, developing methods to systematically select the segmentation parameters and classification approach (i.e.…”

“…Data collected from low altitude (i.e. below-cloud) using unmanned aerial vehicles (UAVs) are now used widely in precision agriculture (Liu et al, 2018 , 2022 ; Shamshiri et al, 2019 ; Tsouros et al, 2019 ; Zhao et al, 2020 ) and provide a viable alternative to satellite data for oil palm mapping. UAVs are particularly suited to collection of high-resolution data for small areas, and so are ideal for the assessment of smallholder plantations (Chong et al, 2017 ; Kilwenge et al, 2021 ; Zhao et al, 2020 ).…”

“…Considerable advances have been made recently to unmanned aerial platforms and various onboard sensors, leading to the proliferation and growing maturity of UAV-based remote sensing applications (Liu et al, 2022 ; Nex & Remondino, 2014 ; Pajares, 2015 ). UAVs can now be fitted with different and sometimes multiple sensors (Aslan et al, 2022 ; Feng et al, 2015 ; Kilwenge et al, 2021 ; Zhao et al, 2020 ), allowing simultaneous collection of complementary datasets useful in a wide range of applications (Kattenborn et al, 2014 ; Lechner et al, 2012 ; Yao et al, 2019 ).…”

“…For instance, standard UAV-derived products, including orthophotos and three-dimensional geometric data, have been collected for urban infrastructure mapping and disaster management (Jia et al, 2022 ; Kerle et al, 2019 ), whilst UAV surveys that extract high spatial, spectral and temporal information have been applied in a range of environmental fields (Biggs et al, 2018 ; Feng et al, 2015 ; McKenna et al, 2017 ; Nowak et al, 2019 ). They have proven especially valuable in agriculture, for vegetation and crop mapping to support farm management and conservation (Chong et al, 2017 ; Liu et al, 2022 ; Pajares, 2015 ; Rokhmana, 2015 ). High spatial resolution digital surface models, which are common UAV-based products, can be integrated with optical sensor data to improve the accuracy of land cover mapping (Chong et al, 2017 ; Tsouros et al, 2019 ; Zhang et al, 2015 ).…”

“…Ways of processing high-resolution UAV data sets have also developed and improved rapidly. For example, geographic, object-based image analysis (GEOBIA or OBIA) approaches are often applied by grouping similar pixels into image objects and then these image objects are classified (Blaschke et al, 2014 ; Liu et al, 2022 ; Tsouros et al, 2019 ; Yao et al, 2019 ).…”