发表机构
The University of Tokyo（东京大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
针对飞行人形机器人在天花板等反重力环境中的行走问题，提出以推力速率为控制输入的全身模型预测控制框架，通过保证推力连续性和引入接触力下界，实现稳定行走，并经仿真和硬件实验验证。
AI 中文摘要
飞行人形机器人有望在多样化的环境中执行任务，而它们现有的运动能力主要局限于空中飞行和地面行走。在复杂三维空间中移动的能力可以极大地扩展其应用范围。对于在天花板及类似反重力环境中的行走运动，全身模型预测控制（MPC）是有效的。然而，行走过程中接触切换伴随的动态结构不连续变化可能引发推力尖峰，导致控制不稳定。因此，在本工作中，我们提出并实现了一种用于反重力双足行走的实时全身MPC框架。首先，我们利用推力的时间导数（即推力速率）作为控制输入来构建全身MPC。该公式保证了接触切换过程中推力轨迹的连续性，同时保留了最优控制问题的稀疏结构以实现快速计算。其次，我们解决了反重力环境中缺乏自然支撑力的问题。我们引入了接触力脚法向分量的下界，并在双支撑阶段平滑地转移这些下界。最后，我们实现了所提出的框架，并通过仿真和硬件实验展示了飞行人形机器人的反重力行走。据我们所知，这是首次针对可变形空中机器人实现多接触全身MPC，以及飞行人形机器人在地面之外的行走演示。
英文摘要
Flying humanoids are expected to perform tasks in diverse environments, while their existing locomotion is mainly limited to aerial flight and ground walking. The capability to move in complex three-dimensional space can greatly expand their application range. For such walking motion on ceilings and similar anti-gravity environments, whole-body MPC is effective. However, the discontinuous changes in dynamic structure accompanying contact switching during walking can induce thrust spikes, resulting in control instability. Therefore, in this work, we propose and implement a real-time whole-body MPC framework for anti-gravity bipedal walking. First, we formulate whole-body MPC using the time derivative of thrust, namely thrust-rate, as the control input. This formulation guarantees continuity of the thrust trajectory during contact switching while preserving the sparse structure of the optimal control problem for fast computation. Second, we address the lack of natural support forces in anti-gravity environments. We introduce lower bounds on the foot-normal component of the contact force, and smoothly transfer them during the doublesupport phase. Finally, we implement the proposed framework and demonstrate anti-gravity walking by a flying humanoid through simulation and a hardware experiment. To the best of our knowledge, this is the first demonstration of multi-contact whole-body MPC for a transformable aerial robot and walking by a flying humanoid beyond the ground.
