Monopedal hopping robots are conceptually simple but highly dynamic and inherently unstable. Achieving robust 3D hopping is still difficult because ground reaction forces are available only during the short stance phase, while the robot is underactuated in flight. A key unresolved issue is how to improve flight-phase control authority. Propeller assistance provides a promising solution, but it requires careful coordination of leg-generated contact forces and propeller thrusts across stance and flight. This paper presents Pro-OMEGA2, a propeller-assisted 3D monopedal hopping robot with an active 3-RSR parallel leg and a trunk-mounted tri-rotor for auxiliary attitude regulation. To address the force coordination challenge, we propose a Hierarchical Force Allocation (HFA) framework based on a single rigid body (SRB) model. The leg generates the main stance contact wrench, while the tri-rotor provides auxiliary attitude regulation, compensating the residual attitude moment in stance and maintaining attitude during flight. Real-robot experiments in indoor and outdoor scenarios demonstrate sustained 3D hopping, including terrain transitions and impulsive push recovery, validating robustness under unmodeled contact and external disturbances.

翻译：单腿跳跃机器人概念简洁但具有高度动态性与内在不稳定性。实现稳健的三维跳跃仍具挑战性，因为地面反作用力仅在短暂的支撑阶段可用，而机器人在飞行阶段处于欠驱动状态。一个关键未解问题是如何提升飞行阶段的控制权。螺旋桨辅助提供了一种有前景的解决方案，但需要精细协调支撑与飞行阶段中腿部产生的接触力与螺旋桨推力。本文提出Pro-OMEGA2——一种螺旋桨辅助的三维单腿跳跃机器人，配备主动3-RSR并联腿与用于辅助姿态调节的躯干安装式三旋翼。为解决力协调难题，我们提出基于单刚体（SRB）模型的分层力分配（HFA）框架。腿部产生主要的支撑接触力旋量，而三旋翼提供辅助姿态调节，补偿支撑阶段的残余姿态力矩并在飞行阶段维持姿态。室内外场景的真实机器人实验展示了持续的三维跳跃能力，包括地形过渡与冲击扰动恢复，验证了在未建模接触与外部干扰下的鲁棒性。