Related Experiment Video
Updated: Aug 6, 2026

Design and Use of an Apparatus for Presenting Graspable Objects in 3D Workspace
Published on: August 8, 2019
An algorithm for the generation of curvilinear wrist motion in an arbitrary plane in three-dimensional space
Abstract:
The elements of an algorithm are presented which predicts for some simple forms (circles and ellipses) the kinematic and figural aspects of the trajectories of the human wrist when these are drawn in any arbitrary plane of free, three-dimensional space. The algorithm is based on theoretical considerations and experimental data and specifies in a unique way the angular motion at the shoulder and elbow joints by utilizing a coordinate transformation, which is only approximate, between the chosen extrinsic (trajectory) and intrinsic (joint angles) parameters. A way to extend the use of this algorithm to generate any arbitrary complex movement in all possible planes of space is also suggested.
Related Concept Videos
Planar Rigid-Body Motion
Planar motion is typically divided into three distinct categories. The first is rectilinear translation, demonstrated by a subway train that moves along...
Curvilinear Motion: Rectangular Components
As the car advances, its position evolves over time. Quantifying the car's velocity involves computing the time...
Curvilinear Motion: Normal and Tangential Components
The positive direction of the t-axis aligns with the increasing position of the car along the curved path, denoted by the unit vector ut. Simultaneously, the n-axis, perpendicular to the t-axis, dissects the curved path into differential arc segments, each forming the arc of a circle with a radius of...
Curvilinear Motion: Polar Coordinates
The particle's location is described using a unit vector along the radial direction. Deriving the particle's position with respect to time...
Cylinders in Three-Dimensional Space
Space Curves

