A Natural Resolution of Bernstein’s Degrees-of-Freedom Problem in Case of Multi-Joint Reaching
A Natural Resolution of Bernstein’s Degrees-of-Freedom Problem in Case of Multi-Joint Reaching
复制标题
伯恩斯坦的自然解决方案
DOI：
10.1109/robio.2004.1521757
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
S. Arimoto
中科院分区：
文献类型：
--
作者：
S. Arimoto
本文旨在挑战伯恩斯坦的问题，称为“自由度的问题”，这是已知的仍然没有解决的生理和机器人的观点。半个多世纪前，伯恩斯坦观察并声称，“灵巧”居民在人类肢体运动出现的参与多关节运动与剩余的自由度。在机器人学中，也有人说机器人机构中自由度的冗余可能有助于提高灵活性和多功能性。然而，运动学冗余会导致从任务描述空间到关节空间的逆运动学的不适定性问题。在机器人研究的历史上，这种逆运动学的不适定性问题还没有被直接攻击，而是通过引入人工性能指标，通过最小化它来唯一地确定逆运动学解来规避。本文引入了“流形上的稳定性”和“子流形的可传递性”两个新概念。在治疗的情况下，人类多关节运动的达到，并表明，感觉反馈，从任务空间到关节空间连同一组足够的阻尼（关节速度反馈）使得整个闭环动力学的任何解能够自然地且协调地收敛到描述一组联合状态的较低维流形，执行任务。这意味着，在不考虑任何类型的逆运动学的情况下，到达任务可以通过具有刚度参数和阻尼系数的适当选择的感觉反馈来完成。它还表明，这些新的概念可以科普恼人的特点，称为“可变性”的冗余关节运动，通常在人类熟练的达到
This paper aims at challenging Bernstein's problem called the "degrees of freedom problem", which is known to remain unsolved from both the physiological and the robotics viewpoints. More than a half century ago A.N. Bernstein observed and claimed that "dexterity" resident in human limb motion emerges from involvement of multijoint movements with surplus DOF. It is also said in robotics that redundancy of DOFs in robot mechanisms may contribute to enhancement of dexterity and versatility. However, kinematic redundancy incurs a problem of illposedness of inverse kinematics from task description space to joint space. In the history of robotics research such illposedness problem of inverse kinematics has not yet been attacked directly but circumvented by introducing an artificial performance index and determining uniquely an inverse kinematics solution by minimizing it. Instead of it, this paper introduces two novel concepts named "stability on a manifold" and "transferability to a submanifold" in treating the case of human multijoint movements of reaching and shows that a sensory feedback from task space to joint space together with a set of adequate dampings (joint velocity feedbacks) enables any solution to the overall closed loop dynamics to converge naturally and coordinately to a lower dimensional manifold describing a set of joint states fulfilling a given motion task. This means that, without considering any type of inverse kinematics, the reaching task can be accomplished by a sensory feedback with adequate choices of a stiffness parameter and damping coefficients. It is also shown that these novel concepts can cope with annoying characteristics called "variability" of redundant joint motions seen typically in human skilled reaching
影响因子：
9.2
作者：
YOSHIKAWA, T
通讯作者：
YOSHIKAWA, T