Isolated mechanical systems—e.g., those floating in space, free-fall, or on a frictionless surface—are able to achieve net rotation by cyclically changing their shape, even if they have no angular momentum. Similarly, swimmers immersed “perfect fluids” are use cyclic shape changes both translate and rotate the swimmer-fluid system has linear Finally, systems fully constrained direct nonholonomi...

Stereoscopic vision is a capability that supports the ability of robots to interact with visually complex environments. Epipolar geometry captures the projective relationship between the cameras in a stereo vision system, assisting in the reconstruction of three-dimensional information. However, a basic problem arises for robots with active vision systems whose cameras move with respect to each...

This article shows that time derivatives of twists and wrenches are indeed screws, in contrast to many classical kinematicians’ believe. Furthermore, it is proven that the “centripetal screw,” as well as the momentum of a rigid body together with all its derivatives, are also screws, and that a rigid body’s dynamics can be geometrically expressed as a screw equation. The paper relies on a somew...