Mechanical and Aerospace Engineering

MAE PhD Exit Seminar

Computational Methods for Dynamics and Mobility Analysis of Complex Mechanisms and Robotic Systems

Kristopher Wehage
Friday, December 16, 1 PM
1016 Academic Surge

Setting up and solving dynamics equations or analyzing the transmission performance of complex mechanisms is tedious and error prone.

Therefore, computer-automated methods are desirable. In this seminar, systematic methods based on graph theory will be presented. The techniques allow setting up a general mechanism’s governing equations and analyzing transmission performance for a wide range of parametric and topological variations.


Three primary new techniques will be discussed. The first technique is a new graph-partitioning algorithm, referred to as “Kinematic Substructuring”, which automatically detects clusters of overlapping chord loops in a mechanism and is used to simplify the processing of the equations of motion. The second method is a custom sparse-matrix solver that exploits the topology of the substructures in solving the equations of motion. The third method is a new measure of transmission performance, referred to as a joint’s “Mobility Number”, which is directly related to a mechanism’s overall mobility.


The algorithms described are designed to be fully automatic – requiring minimal supervision from an analyst for successful execution, robust – capable of handling instantaneous bifurcations and end-of-stroke conditions, and numerically efficient – through the application of numerical reduction strategies and sparse matrix algebra. The tools presented are part of a new software package in development called

STAR2 (Simulation Tool for Automation and Robotics 2).


Date(s) - 12/16/2016
1:00 pm - 2:15 pm

1016 Academic Surge


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