State-Space Characterization of Balance Capabilities in Biped Systems with Segmented Feet.
State-Space Characterization of Balance Capabilities in Biped Systems with Segmented Feet.
复制标题
分节足两足系统平衡能力的状态空间表征。
DOI：
10.3389/frobt.2021.613038
复制
发表时间：
2021
影响因子：
3.4
通讯作者：
Carbone G
中科院分区：
文献类型：
--
作者：
Mummolo C;Akbas K;Carbone G
人类在各种运动任务中保持平衡的能力归因于我们承受与环境的复杂相互作用和协调全身运动的能力。尽管如此，几种稳定性分析方法受到使用过度简化的脚和脚结构以及相应接触模型的限制。因此，现有的稳定性标准往往过于限制，并且不能代表复杂两足动物系统的完整平衡能力。所提出的方法允许的一般ESTA模型（范围从降阶到全身）与分段脚的平衡能力的表征。动态平衡的限制评估的平衡边界（BoB）和相关的新的平衡指标，都制定在质心（COM）状态空间。接触模型可将离散接触模式映射到相应的压力中心约束，从而启用间歇性跟部、平面和趾部接触。为了演示的目的，BoB和平衡指标进行评估的全身ESTA模型与分段的脚代表的人一样的站立姿势在矢状面。在数值上，BoB被构造为一组最大允许COM扰动，该扰动可以沿沿着规定的方向维持。对于BoB的每个点，当它从前后方向上的极端COM速度扰动恢复时，约束轨迹优化算法生成机器人的全身轨迹。平衡能力的情况下，平坦的和分段的脚进行了比较，演示功能的作用，脚模型中的姿势平衡的限制。BoB和平衡指标的状态空间评估允许基于降阶模型在提议的平衡基准和现有稳定性准则之间进行直接比较[例如，线性倒立摆（LIP）]及其相关的稳定性度量[例如，稳定裕度（Margin of Stability，MOS）平衡能力的拟议表征提供了一个重要的基准框架的稳定性，一般脚/脚系统。
The human ability of keeping balance during various locomotion tasks is attributed to our capability of withstanding complex interactions with the environment and coordinating whole-body movements. Despite this, several stability analysis methods are limited by the use of overly simplified biped and foot structures and corresponding contact models. As a result, existing stability criteria tend to be overly restrictive and do not represent the full balance capabilities of complex biped systems. The proposed methodology allows for the characterization of the balance capabilities of general biped models (ranging from reduced-order to whole-body) with segmented feet. Limits of dynamic balance are evaluated by the Boundary of Balance (BoB) and the associated novel balance indicators, both formulated in the Center of Mass (COM) state space. Intermittent heel, flat, and toe contacts are enabled by a contact model that maps discrete contact modes into corresponding center of pressure constraints. For demonstration purposes, the BoB and balance indicators are evaluated for a whole-body biped model with segmented feet representative of the human-like standing posture in the sagittal plane. The BoB is numerically constructed as the set of maximum allowable COM perturbations that the biped can sustain along a prescribed direction. For each point of the BoB, a constrained trajectory optimization algorithm generates the biped’s whole-body trajectory as it recovers from extreme COM velocity perturbations in the anterior–posterior direction. Balance capabilities for the cases of flat and segmented feet are compared, demonstrating the functional role the foot model plays in the limits of postural balance. The state-space evaluation of the BoB and balance indicators allows for a direct comparison between the proposed balance benchmark and existing stability criteria based on reduced-order models [e.g., Linear Inverted Pendulum (LIP)] and their associated stability metrics [e.g., Margin of Stability (MOS)]. The proposed characterization of balance capabilities provides an important benchmarking framework for the stability of general biped/foot systems.
影响因子：
3.7
作者：
Pickle NT;Wilken JM;Fey NP;Silverman AK
通讯作者：
Silverman AK