algorithm enabling 20x longer simulations

summary

The real world is not perfect. So, if we measure the motion of a person's body as they walk, and measure how hard their feet hit the ground while they walk, those measurements will not be completely consistent: namely, force will not exactly equal mass times acceleration. My colleagues and I developed a new "residual reduction algorithm" that corrects these errors to make force equal mass times acceleration in our measured data. This algorithm has been used by hundreds of users and enabled the generation of an accurate walking simulation 20 times longer than previously feasible.

Over 700 publications have cited the residual reduction algorithm (RRA) as of January 8, 2019.

source code

The residual reduction algorithm (RRA) is distributed as part of the OpenSim source code. The source code for the residual reduction algorithm (RRA) is in this header file and this implementation file.

media

• The National Institutes of Health feature this research as a "cool movie" in their Biomedical Beat gallery
• Movie of detailed, physiologically accurate 3D simulation of ten gait cycles of walking
• Poster (17.1 MB) presented at Biomedical Computation at Stanford on the residual reduction algorithm
• Paper for keynote talk on the residual reduction algorithm
• Movies of erroneous walking simulation without the residual reduction algorithm vs. accurate walking simulation using the residual reduction algorithm
• Movies of erroneous walking simulation without the residual reduction algorithm vs. accurate walking simulation using the residual reduction algorithm
• Movies and graphs showing how our algorithm improves accuracy of forces and motion
• Talk on residual reduction algorithm and sensitivity analysis
• Article in Computational Methods in Biomechanics and Biomedical Engineering where the simulation of ten gait cycles of walking was published
• Additional documentation on the residual reduction algorithm