  Multi-modal robots expand their operations from one working medium to
another, land to air for example. The majorities of multi-modal robots mainly
refer to platforms that operate in two different media. However, for
all-terrain tasks, there are seldom research to date in the literature.
Generally, locomotions in different working media, i.e. land, water and air,
require different propelling actuators, and thus the triphibian system becomes
bulky. To overcome this challenge, we proposed a triphibian robot and provide
the robot with driving forces to perform all-terrain operations in an efficient
way. A morphable mechanism is designed to enable the transition between
different motion modes, and specifically a cylindrical body is implemented as
the rolling mechanism in land mode. Detailed design principles of different
mechanisms and the transition between various locomotion modes are analyzed.
Finally, a triphibian robot prototype is fabricated and tested in various
working media with both mono-modal and multi-modal functionalities. Experiments
have verified our platform, and the results show promising adaptions in future
exploration tasks in various working scenarios.
