Dynamic locomotion for passive-ankle biped robots and humanoids using whole-body locomotion control
Dynamic locomotion for passive-ankle biped robots and humanoids using whole-body locomotion control
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DOI：
10.1177/0278364920918014
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发表时间：
2020-06-10
影响因子：
9.2
通讯作者：
Sentis, Luis
中科院分区：
文献类型：
--
作者：
Kim, Donghyun;Jorgensen, Steven Jens;Sentis, Luis
全身控制是一种面向任务的类人机器人局部操作行为反馈控制方法。WBC与基于模型的步行控制器的结合已广泛应用于各种仿人机器人。然而，迄今为止，WBC方法尚未用于无支撑的被动踝关节动态运动。因此，在本文中，我们设计了一种新的WBC，称为全身运动控制器（WBLC），可以在无支撑的被动脚踝双足机器人上实现实验性动态行走。WBLC的一个关键方面是放松接触约束，使控制命令在切换脚接触时产生减少的抽搐。为了实现鲁棒动态运动，我们对动态行走算法进行了深入的不确定性分析，该算法被称为时间-速度反转（TVR）规划器。不确定性研究是基础，它使我们能够改进机器人的控制算法和机械结构，以实现可容忍的不确定性。此外，我们进行了广泛的实验：(1)无支撑的动态平衡（即原地踏步）与六自由度双足，水星；(2)水星无支撑定向行走；(3)与水星一起在不规则和光滑的地形上行走;4)使用我们新设计的十自由度粘弹性液冷双足机器人DRACO进行原地行走。总的来说，这项工作的主要贡献是：(a)使用WBLC控制器和TVR规划器实现被动踝关节两足动物无支撑动态运动的各种模式；(b)进行不确定度分析，以改善水星的机械结构和控制器;(c)设计一种全身控制策略，减少行走时的运动抽搐。
Whole-body control (WBC) is a generic task-oriented control method for feedback control of loco-manipulation behaviors in humanoid robots. The combination of WBC and model-based walking controllers has been widely utilized in various humanoid robots. However, to date, the WBC method has not been employed for unsupported passive-ankle dynamic locomotion. As such, in this article, we devise a new WBC, dubbed the whole-body locomotion controller (WBLC), that can achieve experimental dynamic walking on unsupported passive-ankle biped robots. A key aspect of WBLC is the relaxation of contact constraints such that the control commands produce reduced jerk when switching foot contacts. To achieve robust dynamic locomotion, we conduct an in-depth analysis of uncertainty for our dynamic walking algorithm called the time-to-velocity-reversal (TVR) planner. The uncertainty study is fundamental as it allows us to improve the control algorithms and mechanical structure of our robot to fulfill the tolerated uncertainty. In addition, we conduct extensive experimentation for: (1) unsupported dynamic balancing (i.e., in-place stepping) with a six-degree-of-freedom biped, Mercury; (2) unsupported directional walking with Mercury; (3) walking over an irregular and slippery terrain with Mercury; and 4) in-place walking with our newly designed ten-DoF viscoelastic liquid-cooled biped, DRACO. Overall, the main contributions of this work are on: (a) achieving various modalities of unsupported dynamic locomotion of passive-ankle bipeds using a WBLC controller and a TVR planner; (b) conducting an uncertainty analysis to improve the mechanical structure and the controllers of Mercury; and (c) devising a whole-body control strategy that reduces movement jerk during walking.