Tilt-Ropter: A Novel Hybrid Aerial and Terrestrial Vehicle with Tilt Rotors and Passive Wheels

2026-02-02

AI Summary

This work addresses the high energy consumption, strong control coupling, and poor environmental adaptability of existing hybrid aerial–ground vehicles during multimodal locomotion. To overcome these limitations, the authors propose a fully actuated configuration integrating tilting rotors with passive wheels, enabling seamless aerial–ground transitions and precise trajectory tracking via nonlinear model predictive control (NMPC) that explicitly handles contact constraints. The approach innovatively combines force/torque decoupling under a fully actuated architecture, real-time external torque estimation, and energy-optimal allocation across redundant actuators, significantly enhancing system efficiency and robustness. Experimental results demonstrate that the proposed design achieves high-precision trajectory tracking and reduces ground-mode power consumption by 92.8%, making it well-suited for large-scale, long-endurance missions.

Technology Category

• Intelligent Robots: Multimodal Perception & Sensor Fusion
• Planning, Routing, and Scheduling: Mixed Discrete/Continuous Planning
• Search and Optimization: Mixed Discrete/Continuous Search

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments
• Responsible Web: Machine-in-the-loop, human agency and autonomy
• User Modeling, Personalization and Recommendation: Accountability, Transparency, and Ethics for personalization

Abstract

In this work, we present Tilt-Ropter, a novel hybrid aerial-terrestrial vehicle (HATV) that combines tilt rotors with passive wheels to achieve energy-efficient multi-mode locomotion. Unlike existing under-actuated HATVs, the fully actuated design of Tilt-Ropter enables decoupled force and torque control, greatly enhancing its mobility and environmental adaptability. A nonlinear model predictive controller (NMPC) is developed to track reference trajectories and handle contact constraints across locomotion modes, while a dedicated control allocation module exploits actuation redundancy to achieve energy-efficient control of actuators. Additionally, to enhance robustness during ground contact, we introduce an external wrench estimation algorithm that estimates environmental interaction forces and torques in real time. The system is validated through both simulation and real-world experiments, including seamless air-ground transitions and trajectory tracking. Results show low tracking errors in both modes and highlight a 92.8% reduction in power consumption during ground locomotion, demonstrating the system's potential for long-duration missions across large-scale and energy-constrained environments.

Problem

• hybrid aerial-terrestrial vehicle
• energy-efficient locomotion
• multi-mode mobility
• air-ground transition
• environmental adaptability

Innovation

• tilt rotors
• hybrid aerial-terrestrial vehicle
• nonlinear model predictive control
• actuation redundancy
• external wrench estimation