Abstract
Terrestrial gastropods, such as snails, are able to crawl by generating traveling waves under the ventral foot. Although the speed of the animal is slow, they are able to adapt to any surface with continuous contact point by using their soft single ventral foot. These characteristics are difficult to realize by conventional rigid robots, such as wheeled, legged, and crawler. If those movement characteristics can be artificially achieved, many application can be realized. For example, research robot for confined space purposes, or a mobile device capable of transporting fragile objects without damaging the environment. In this paper, we propose a method to create various waveforms for our proposed actuator called “Wavy-sheet”. Wavy-sheet is a pneumatic sheet actuator that can generate traveling waves inspired by gastropod’s locomotion. Several rubber tubes are passed through the sleeve which determines the waveform of the actuator. By arranging the inner rubber tubes, various waveforms can be designed that has different characteristics such as amplitude, velocity, and stiffness. First, we derived a combination of waveforms. The result showed that there are mainly three kinds of waveforms that are actuated by three input. Next, amplitude and velocity had been analyzed. Finally, two prototypes of the actuators had been fabricated and characteristics were measured by some experiments. The results showed that each wave has different characteristics and it is effective to select the waveform depending on the application.
