A Visco-Hyperelastic Lattice-Based Arm Structure to Improve UAV Collision Resilience

Traditional UAVs often suffer severe structural damage during high-speed collisions. Recent research has explored sensing, control, and design strategies to enhance collision resilience. This work presents fully passive, soft continuum-lattice arms that combine visco-hyperelastic materials with nonlinear lattice geometries to trigger controlled buckling of the beams and absorb impact energy. Visco-hyperelastic parameters are identified from quasi-static and dynamic tensile tests on the material and then implemented in finite element models to optimize lattice porosity and distribution for force mitigation under quasi-static and dynamic loading conditions. Experimental validation of the simulations for the optimized beam configuration shows good agreement, with MAE 6.7% and RMSE 7% in quasi-static loading and MAE 12.1% and RMSE 14% in dynamic loading. Controlled drop tests on a quadrotor prototype demonstrate superior impact energy absorption and force mitigation compared with a bulk material design (up to a 99% increase in specific energy absorption and up to a 65% reduction in peak impact force). Furthermore, the latticed UAV is flown voluntarily and then dropped onto the ground, maintaining low thrust losses of 0.42 ± 0.26% and structural integrity after impact.