Decentralized Control Mechanism for Adaptive Locomotion in Centipedes: Transition Between Walking and Peristalsis

Centipedes adapt to various environmental changes by using different locomotor patterns. For example, when walking on land at high speed, they enhance propulsion by coordinating leg movements with body undulation. When climbing a rod, they combine leg movements with peristaltic body motion. In water, they swim solely by body undulation. Interestingly, when transitioning between different environments, such as water and land, they exhibit a mixture of different locomotor patterns.Understanding the underlying control principles of such flexible behaviors in centipedes will contribute to developing multi-legged robots capable of adapting to unpredictable terrain. Some studies were conducted focusing on the adaptive locomotion of centipedes. However, these have been limited to understanding behaviors in open spaces. In confined spaces, where leg movement may be restricted, centipedes are likely to rely on other body parts for locomotion. Understanding locomotion in confined spaces, as well as transitions between confined and open environments, could provide insights into control mechanisms that enable flexible adaptation to complex and diverse environments. To address this issue, we observed the locomotion of centipedes as they passed through a narrow aisle. Additionally, to understand the control principles behind this behavior, we developed a mathematical model. We found that centipedes perform peristaltic movement in the narrow aisle, followed by a transition to walking after passing through the aisle into an open space. Based on this finding, we extended the control rules proposed in our previous walking model and could replicate similar behaviors. Specifically, we added local sensory feedback based on the leg's bending angle, enabling adaptive transitions between walking and peristalsis in response to environmental constraints.