Bumper Drone: Elastic Morphology Design for Aerial Physical Interaction

Abstract

Aerial robots are evolving from avoiding obstacles to exploiting the environmental contact interactions for navigation, exploration and manipulation. A key challenge in such aerial physical interactions lies in handling uncertain contact forces on unknown targets, which typically demand accurate sensing and active control. We present a drone platform with elastic horns that enables touch-and-go manoeuvres - a self-regulated, consecutive bumping motion that allows the drone to maintain proximity to a wall without relying on active obstacle avoidance. It leverages environmental interaction as a form of embodied control, where low-level stabilisation and near-obstacle navigation emerge from the passive dynamic responses of the drone-obstacle system that resembles a mass-spring-damper system. Experiments show that the elastic horn can absorb impact energy while maintaining vehicle stability, reducing pitch oscillations by 38% compared to the rigid horn configuration. The lower horn arrangement was found to reduce pitch oscillations by approximately 54%. In addition to intermittent contact, the platform equipped with elastic horns also demonstrates stable, sustained contact with static objects, relying on a standard attitude PID controller.

Figures (9)

• Figure 1: Bumper drone: a 700.0 flying robot that has a self-recovery mechanism after collisions and can exert force on objects while maintaining its stability.
• Figure 2: Drawing of the hypothetical behaviour of our horn design attached to the drone during collision with a vertical wall. (A) The drone approaches the wall with forward velocity and initial pitch angle. (B) Two upper horns make initial contact with the wall. (C) Reaction forces and moments from the wall induce an anticlockwise rotation of the drone, bringing two lower horns into contact. (D) The lower horns produce counter-reaction forces and moments, allowing the drone to rebound and stabilise its attitude passively.
• Figure 3: Experimental setup and detailed design. (A) Instron testing machine setup for calibration with compression direction indicated. (B) Side view and cross-section with dimensions. (C) Overview design comprising four flex sensors placed inside left and right 3D-printed TPU housing.
• Figure 4: (A) Contact force response of upper and lower horns. (B) Displacement response of upper and lower horns (C) Signal processing of one horn's signal after interaction with a vertical wall.
• Figure 5: (A) The horn resistance responses of upper horns (red) and lower horns (blue) of one flight experiment. The plot shows that the upper horns make contact first, and the wall generates a positive pitch attitude, causing the drone to rotate, followed by lower horn contact. The total collision count is 6 occurrences. (B) The pitch rate of the drone platform corresponding to the resistance response.