Review of Research on Landing Gear Design for Multi-Rotor UAV Platforms

As a critical load-bearing system connecting the multi-rotor UAV airframe to the ground, the design quality of the landing gear directly affects flight safety and operational stability during takeoff and landing in complex environments. This paper presents a systematic review of the state-of-the-art in multi-rotor UAV landing gear design, with comparative references to fixed-wing alternatives where relevant. Beginning with an explicit, reproducible literature retrieval protocol, the study examines 86 peer-reviewed sources spanning 2014–2025. Structural configurations—including traditional fixed struts, telescopic landing gear, bio-inspired adaptive systems, modular designs, inflatable supports, and intelligent active-control architectures—are critically analyzed across diverse application scenarios, with particular emphasis on agricultural monitoring in paddy-fields. Key technical challenges are discussed in depth, including lightweight design, multi-environment adaptability, intelligent control, and advanced materials. In light of the specific requirements of agricultural UAVs during field operations, the paper evaluates cutting-edge research directions such as anti-rollover mechanisms, anti-sinkage capabilities, and non-destructive monitoring, supported by quantitative terrain–mechanics analysis. The review further expands the discussion of intelligent landing systems by detailing sensor-fusion architectures (vision, LiDAR, IMU/GNSS-RTK, soil-pressure transducers) and model-predictive adaptive-landing decision-making. Future development trends are outlined, proposing trajectories toward intelligentization, biomimicry, and multifunctional integration, thereby providing theoretical guidance for the optimization of landing gear design in precision agriculture.