In a musculoskeletal system, internal tensile forces are generated among the muscles because it is a redundant system. The balancing of the internal tensile forces for a given posture generates a potential field in the system. Therefore, the potential field is utilized for the sensorless feedforward position control and improvement of stability based on the feedback method. However, the stability of the internal tensile forces is strongly influenced by the muscular arrangement. Previous studies showed that a stable condition can be identified through the minimization of the potential at a desired posture, and the sufficient condition has been theoretically established; however, the geometric condition of the muscular arrangement has not been determined. To effectively exploit the characteristics of the internal tensile forces, the geometric condition must be elucidated in the design of a musculoskeletal system. This paper aims to clarify the geometric condition to generate stable internal tensile forces. Based on the conditions generating the potential that is minimum at the desired posture, the paper analyzes that the geometric condition on a musculoskeletal structure with two-link and six-muscle. Additionally, the identified condition is assessed based on simulations. As a result, we revealed the geometric condition of the muscular arrangement to generate stable internal tensile forces. By designing the muscular arrangement to satisfy the condition, the stability of the internal tensile forces is ensured, and consequently, a control method utilizing the characteristics of the internal tensile force is stably implemented.

中文翻译：

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基于内力稳定性的二联六肌结构的几何条件

在肌肉骨骼系统中，内部张力在肌肉之间产生，因为它是多余的系统。给定姿势的内部拉力的平衡会在系统中产生一个势场。因此，势场用于基于反馈方法的无传感器前馈位置控制和稳定性的改善。但是，内部张力的稳定性受肌肉排列的强烈影响。先前的研究表明，可以通过将所需姿势的电位降到最低来确定稳定的状态，并且在理论上已经建立了充分的状态。但是，尚未确定肌肉排列的几何条件。为了有效利用内部拉力的特性，在设计肌肉骨骼系统时必须阐明其几何条件。本文旨在阐明产生稳定内部拉力的几何条件。基于在所需姿势下产生最小电位的条件，本文分析了具有两个链接和六个肌肉的肌肉骨骼结构上的几何条件。另外，基于模拟评估所识别的状况。结果，我们揭示了肌肉排列的几何条件，以产生稳定的内部拉力。通过设计满足条件的肌肉布置，确保了内部拉力的稳定性，因此，稳定地实现了利用内部拉力的特性的控制方法。