Safely catching aerial micro-robots in mid-air using an open-source aerial robot with soft gripper

Abstract

This work focuses on catching safely an aerial micro-robot in mid-air using another aerial robot that is equipped with a universal soft gripper. To avoid aerodynamic disturbances such as downwash, that would push the target robot away, we follow a horizontal grasping approach. To this end, the article introduces a gripper design based on soft actuators that can stay horizontally straight with a single fixture and maintain sufficiently compliance in order to bend when air pressure is applied. Further, we develop the Soft Aerial Gripper (SoAG), an open-source aerial robot equipped with the developed soft end-effector and that features an onboard pneumatic regulation system. Experimental results show that the developed low-cost soft gripper has fast opening and closing responses despite being powered by lightweight air pumps, responses that are comparable to those of a commercially available end-effector tested we test against. Static grasping tests study the soft gripper’s robustness in capturing aerial micro-robots under aerodynamic disturbances. We experimentally demonstrated the feasibility of using the SoAG robot to catch a hovering micro-robot with or without propeller guards. The feasibility of dynamic catching is also shown by capturing a moving aerial micro-robot with a velocity of 0.2 m/s. The free flight performance of the SoAG robot is studied against a conventional quadrotor and in different gripper and payload status.

Online Search-Based Collision-Inclusive Motion Planning and Control for Impact-Resilient Mobile Robots

“…Our design differs from works [1,25] in its capacity to enable stabilization from high-speed collisions with large impact, and estimate contact forces in presence of frame compliance. The robot chassis is shared with our prior work [34] and consists of custom carbon fiber frames, a flight controller (Pixhawk), and an ARM-based multi-core processor (Odroid). The four frame arms measure 0.19 m, and the contact arm measures 0.28 m in free flight.…”

Koopman Operators for Modeling and Control of Soft Robotics

“…In contrast to their rigid counterparts, soft robots have bodies made out of intrinsically soft/or extensible materials, which exhibit unprecedented adaptation to complex environments and can absorb impact energy for safe interactions with the environment, other robots, and even humans [1]. Soft robots have been applied in all aspects of robotic research, including but not limited to assistive robotics [2]- [4], grasping [5]- [7], ground mobility [8], [9], legged locomotion [10], [11], aerial robots [12] and underwater robots [13].…”

Closed-loop Position Control of a Pediatric Soft Robotic Wearable Device for Upper Extremity Assistance

“…Soft wearable assistive devices, in particular, can afford a wide variety of methods for actuation, sensing and control, which in many cases are intertwined with each other and can be adjusted to meet the characteristics of the infant population. Actuation methods can utilize 3D-printing [13]- [15], casting [16]- [18] or fabric [19]- [23] to improve strength [2], [24] and minimize fatigue [4], [21]. Several of the current actuator designs employed in wearable devices are pneumatic-based (as in this work too), in an effort to facilitate motion while providing comfort and safety with minimal constraints on the arms [25].…”