title: Gait control in a soft robot by sensing interactions with the environment using self-deformation.
abstract: All animals use mechanosensors to help them move in complex and changing environments. With few exceptions, these sensors are embedded in soft tissues that deform in normal use such that sensory feedback results from the interaction of an animal with its environment. Useful information about the environment is expected to be embedded in the mechanical responses of the tissues during movements. To explore how such sensory information can be used to control movements, we have developed a soft-bodied crawling robot inspired by a highly tractable animal model, the tobacco hornwormManduca sexta. This robot uses deformations of its body to detect changes in friction force on a substrate. This information is used to provide local sensory feedback for coupled oscillators that control the robot's locomotion. The validity of the control strategy is demonstrated with both simulation and a highly deformable three-dimensionally printed soft robot. The results show that very simple oscillators are able to generate propagating waves and crawling/inching locomotion through the interplay of deformation in different body parts in a fully decentralized manner. Additionally, we confirmed numerically and experimentally that the gait pattern can switch depending on the surface contact points. These results are expected to help in the design of adaptable, robust locomotion control systems for soft robots and also suggest testable hypotheses about how soft animals use sensory feedback.
authors.affiliation: Graduate School of Information Science and Technology , The University of Tokyo , Takeda Bldg. Rm. 309, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032 , Japan.
authors.forename: Takuya
authors.identifier: 0000-0002-2244-9963
authors.initials: T
authors.lastname: Umedachi
authors.affiliation: Research Institute of Electrical Communication , Tohoku University , 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 , Japan.
authors.forename: Takeshi
authors.identifier: 0000-0002-2033-4695
authors.initials: T
authors.lastname: Kano
authors.affiliation: Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan; Japan Science and Technology Agency, CREST, 7 Goban-cho, Chiyoda-ku, Tokyo 102-0075, Japan.
authors.forename: Akio
authors.initials: A
authors.lastname: Ishiguro
authors.affiliation: Department of Biology , Tufts University , 200 Boston Avenue, Medford, MA 02155 , USA.
authors.forename: Barry A
authors.initials: BA
authors.lastname: Trimmer
keywords: behavioural diversity; biologically inspired robot; decentralized control; mechanosensing; soft-bodied robot