Modeling and Control of Soft Robotic Tail Based Aerial Maneuvering (STAM) System: Towards Agile Self-Righting with a Soft Tail

Recent studies have demonstrated feasible aerial maneuvering with rigid tails. However, soft robotic tails were never investigated for aerial maneuvering applications, and no modeling strategy was found that exploits the soft robotic tail based aerial maneuvering (STAM) system kinematics for flight phase control (aerial self-righting). In this work, we provide the feasible solution to flight phase control of STAM systems (1-DOF and 2-DOF) by proposing their forward kinematics, differential kinematics, and flight phase models. We integrate Piecewise constant curvature (PCC) and Augmented rigid robot (ARR) modeling formulations to model the kinematics of 1-DOF STAM (body-tail pitch or body-tail yaw) system and propose its flight phase model & control. Then, we introduce the soft-tail “arbitrary-plane” bending which aids the extension of integrated modeling approaches to model the forward kinematics of 2-DOF (pitch and yaw) soft tail. The 2-DOF STAM system (body-tail pitch and yaw together) is composed of rigid body, cable-driven soft tail, and actuation units, so we develop their differential kinematics which maps the tail shape velocities with the body orientation angular rates and the tail cable velocities respectively. Together with the forward and differential kinematics, we present flight phase model and control of 2-DOF STAM system which ensures the conservation of total angular momentum. The simulations, which demonstrates the self-righting maneuvers with STAM systems are provided and the effective simulation results validates our proposed models.