Instantaneous Invariants in Three-Dimensional Kinematics

Abstract

The paper generalizes the concepts of canonical systems and instantaneous invariants from planar to three-dimensional kinematics. It presents a systematic procedure to determine the instantaneous invariants. An example is included for illustration. The instantaneous invariants are derived on the basis of line coordinates, therefore they are useful for the characterization of higher-order intrinsic properties of a ruled surface—the path trajectory of an arbitrary line embedded in a rigid body in three-dimensional motion. It is hoped that this study may be useful for the rational design of spatial mechanisms for surface generation.