A fluid-actuated driving mechanism for rolling robots

There are important issues in the design of the driving mechanism for the rolling robots. The actuator is expected to operate without occupying the whole space of the carrier body. This property gets harder to achieve as the degree of freedom in driving mechanism increases. This paper proposes an alternative fluid actuator for rolling bodies e.g., sphere or disc. The designed mechanism has a circular pipe that is propelled by rotating spherical mass (core) inside a fluid medium. In this work, we first establish the dynamics of the rolling circular pipe. Then, the internal driving unit is modeled and combined with rotating mass dynamics. Finally, the model simulations are conducted for observing motion patterns of the carrier body and locomotion abilities of the rotating core. The results show the feasibility of the proposed actuator for future applications

Darboux-Frame-Based Parametrization for a Spin-Rolling Sphere on a Plane: A Nonlinear Transformation of Underactuated System to Fully-Actuated Model

This paper presents a new kinematic model based on the Darboux frame for motion control and planning. In this work, we show that an underactuated model of a spin-rolling sphere on a plane with five states and three inputs can be transformed into a fully-actuated one by a given Darboux frame transformation. This nonlinear state transformation establishes a geometric model that is different from conventional state-space ones. First, a kinematic model of the Darboux frame at the contact point of the rolling sphere is established. Next, we propose a virtual surface that is trapped between the sphere and the contact plane. This virtual surface is used for generating arc-length-based inputs for controlling the contact trajectories on the sphere and the plane. Finally, we discuss the controllability of this new model. In the future, we will design a geometric path planning method for the proposed kinematic model.Comment: 17 pages, 7 figures, Accepted at Mechanism and Machine Theory Elsevie