D M Hartley

Monkton Hall Hospital, University of Salford

Papers

Total Citations

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About

D. M. Hartley has made foundational contributions to the mathematical analysis of screw systems, a critical framework in robotics, kinematics, and machinery design. Their primary research focuses on developing invariant measures to quantify the closeness to linear dependency of lines and screws—a problem central to understanding singular configurations in mechanical systems. Hartley’s most cited work, “Invariant Measures of Closeness to Linear Dependency of Screw Systems” (2006, 9 citations), introduces a novel, general analytical method that yields n invariant scalars for an n-system of screws. This approach evaluates the maximum available scalar or Klein product, providing a rigorous, coordinate-independent tool for singularity analysis. Earlier work, “Invariant Measures of the Closeness to Linear Dependence of Six Lines or Screws” (2001, 5 citations), established a system of measures that remain strictly invariant under coordinate transformations, addressing a key gap when systems are near—but not at—singular configurations. These contributions offer engineers and researchers a precise, mathematically elegant way to assess robustness and performance in robotic mechanisms and spatial linkages, with lasting impact on the field of theoretical kinematics.