Modeling and Analysis of Non-unique Behaviors in Multiple Frictional Impacts

Almost every model of contact for robotics has some issue with predicting behaviors when multiple frictional collisions occur simultaneously between rigid bodies—either as a lack of proven existence of solutions or lack of ability to capture the non-unique behaviors observable in simplest of real-world systems. We derive and characterize what we believe to be the only model of simultaneous frictional impact that resolves both of these issues.


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A Quasi-static Model and Simulation Approach for Pushing, Grasping, and Jamming

While quasi-static models are often used for non-prehensile manipulation, they broadly remain incapable of capturing grasping and jamming behaviors, which are essential for dexterous manipulation. We rectify these issues by explicitly modeling the internal dynamics of the manipulator, allowing for guaranteed existence of solutions for arbitrary manipulator commands. We formulate both continuous and time-steeping dynamics as tractable Linear Complementarity Problems.

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