The Soft-PVTOL: Modeling and control

Abstract

This paper introduces, for the first time, the soft planar vertical take-off and landing (Soft-PVTOL) aircraft. Unlike conventional PVTOL and multi-rotor systems, where position alterations inevitably impact orientation due to their underactuated design, the Soft-PVTOL offers the unique advantage of decoupling these dynamics, enabling unprecedented maneuverability and precision. We have demonstrated that the Soft-PVTOL can be accurately modeled using the Euler–Lagrange framework under a constant curvature assumption for the soft arms. This approach provides a significant advantage for designing control strategies tailored explicitly for soft aerial robots, offering a concise and singularity-free mathematical model that accurately captures the system’s dynamics. Furthermore, the model’s flexibility supports extensions to multiple constant curvature segments per arm, allowing scalability to more complex configurations and further broadening its applicability to the field of soft aerial robotics. Having demonstrated that the Soft-PVTOL satisfies the passivity property under our model, we designed a passivity-based control law to ensure global exponential convergence of the tracking error. Numerical simulations, including perturbations affecting the system, validate the robustness of the proposed approach, demonstrating effective trajectory tracking and decoupled position-orientation control, even under adverse conditions. These results demonstrate the Soft-PVTOL’s adaptability and maneuverability, marking a significant advancement in aerial robotics and establishing a foundation for future research into more sophisticated and versatile soft aerial robot designs.