Development and Numerical Evaluation of an Oleo-Pneumatic Landing Gear and Test System for a Small UAV: An Engineering Capstone Project

This study presents the development and numerical evaluation of a low-cost oleo-pneumatic landing gear and drop-test system for a small UAV as a multidisciplinary engineering technology capstone project. The developed prototype consists of a two-chamber oleo-pneumatic shock absorber, wheel assembly, and custom drop-test structure fabricated primarily from commercially available components. A nonlinear MATLAB/Simulink model was developed to evaluate landing impact dynamics, incorporating hydraulic damping, polytropic pneumatic compression, tire compliance, and coupled sprung–unsprung mass motion. The baseline simulation considered a supported mass of 33 kg per main landing gear unit, representing an approximately 66 kg UAV during a symmetric two-point landing, with an initial vertical velocity of 3.05 m/s (10 ft/s). The results demonstrated the complementary effects of hydraulic damping and pneumatic resistance, with a maximum predicted shock-absorber displacement of 0.215 m (62% of the available stroke) and a peak supported-mass acceleration of approximately 2.6 g. The project demonstrates the integration of engineering analysis, practical design constraints, and prototype development within a low-cost educational platform. Future work will focus on instrumented drop testing to experimentally validate and refine the numerical model.