Stability Recognition with Active Vibration for Bracing Behaviors and Motion Extensions Using Environment in Musculoskeletal Humanoids

TL;DR

This work tackles the challenge of controlling flexible musculoskeletal humanoids by leveraging environmental bracing and an active vibration-based stability recognition method. By vibrating a selected muscle group and observing the propagation through observer muscles via FFT-derived metrics, the authors define a stability score $S$ that guides bracing and motion extension. Systematic preliminary experiments reveal how environment, amplitude, frequency, grouping, and posture influence the stability measure, informing practical parameter choices. The study demonstrates motion extension and bracing tasks where stability-aware interactions with the environment enhance control accuracy, with potential to extend to other robots through sensor fusion and broader applicability. Overall, the approach provides a concrete, physics-inspired mechanism to stabilize soft-bodied robots using their surroundings, enabling safer and more capable manipulation and locomotion.

Abstract

Although robots with flexible bodies are superior in terms of the contact and adaptability, it is difficult to control them precisely. On the other hand, human beings make use of the surrounding environments to stabilize their bodies and control their movements. In this study, we propose a method for the bracing motion and extension of the range of motion using the environment for the musculoskeletal humanoid. Here, it is necessary to recognize the stability of the body when contacting the environment, and we develop a method to measure it by using the change in sensor values of the body when actively vibrating a part of the body. Experiments are conducted using the musculoskeletal humanoid Musashi, and the effectiveness of this method is confirmed.

Figures (16)

• Figure 1: Bracing behavior and motion extension using environment.
• Figure 2: The basic musculoskeletal structure.
• Figure 3: The concept of active vibration and stability recognition.
• Figure 4: The musculoskeletal humanoid Musashi and its muscle grouping used in this study.
• Figure 5: Experimental setup of environments used in this study.