Publications (15)
Understanding How Synthetic Impurities Affect Glyphosate Solubility and Crystal Growth Using Free Energy Calculations and Molecular Dynamics Simulations
Alejandro Castro, Ignacio Sanchez-Burgos, Nuria H. Espejo +3
Glyphosate, the most widely used herbicide worldwide, crystallizes through complex intermolecular interactions that are strongly influenced by synthesis-derived impurities. Underst…
A Careful Examination of Large Behavior Models for Multitask Dexterous Manipulation
TRI LBM Team, Jose Barreiros, Andrew Beaulieu +79
Robot manipulation has seen tremendous progress in recent years, with imitation learning policies enabling successful performance of dexterous and hard-to-model tasks. Concurrently…
A Convex Formulation of Frictional Contact between Rigid and Deformable Bodies
Xuchen Han, Joseph Masterjohn, Alejandro Castro
We present a novel convex formulation that models rigid and deformable bodies coupled through frictional contact. The formulation incorporates a new corotational material model wit…
Inverse Dynamics Trajectory Optimization for Contact-Implicit Model Predictive Control
Vince Kurtz, Alejandro Castro, Aykut Ãzgün Ãnol +1
Robots must make and break contact with the environment to perform useful tasks, but planning and control through contact remains a formidable challenge. In this work, we achieve r…
Right-Side-Out: Learning Zero-Shot Sim-to-Real Garment Reversal
Chang Yu, Siyu Ma, Wenxin Du +9
Turning garments right-side out is a challenging manipulation task: it is highly dynamic, entails rapid contact changes, and is subject to severe visual occlusion. We introduce Rig…
A Convex Formulation of Material Points and Rigid Bodies with GPU-Accelerated Async-Coupling for Interactive Simulation
Chang Yu, Wenxin Du, Zeshun Zong +3
We present a novel convex formulation that weakly couples the Material Point Method (MPM) with rigid body dynamics through frictional contact, optimized for efficient GPU paralleli…
Embedded IPC: Fast and Intersection-free Simulation in Reduced Subspace for Robot Manipulation
Wenxin Du, Chang Yu, Siyu Ma +7
Physics-based simulation is essential for developing and evaluating robot manipulation policies, particularly in scenarios involving deformable objects and complex contact interact…
CENIC: Convex Error-controlled Numerical Integration for Contact
Vince Kurtz, Alejandro Castro
State-of-the-art robotics simulators operate in discrete time. This requires users to choose a time step, which is both critical and challenging: large steps can produce non-physic…
Simple sign epistasis and evolutionary detours in fitness landscapes
Paolo Ribeca, Alejandro Castro, Alejandro Lage-Castellanos +8
In epistatic fitness landscapes, the fitness effect of a mutation depends on the genetic background and may even switch between deleterious and beneficial depending on the presence…
MPM Lite: Linear Kernels and Integration without Particles
Xiang Feng, Yunuo Chen, Chang Yu +6
In this paper, we introduce MPM Lite, a new hybrid Lagrangian/Eulerian method that eliminates the need for particle-based quadrature at solve time. Standard MPM practices suffer fr…
An Unconstrained Convex Formulation of Compliant Contact
Alejandro Castro, Frank Permenter, Xuchen Han
We present a convex formulation of compliant frictional contact and a robust, performant method to solve it in practice. By analytically eliminating contact constraints, we obtain…
Irrotational Contact Fields
Alejandro Castro, Xuchen Han, Joseph Masterjohn
We present a framework for generating convex approximations of complex contact models, incorporating experimentally validated models like Hunt & Crossley coupled with Coulomb's law…
Xenophobia based on a few attributes can impede society's cohesiveness
Alejandro Castro, Tuan Minh Pham, Ernesto Ortega +1
Xenophobic interactions play a role as important as homophilic ones in shaping many dynamical processes on social networks, such as opinion formation, social balance, or epidemic s…
Proximity and Visuotactile Point Cloud Fusion for Contact Patches in Extreme Deformation
Jessica Yin, Paarth Shah, Naveen Kuppuswamy +5
Visuotactile sensors are a popular tactile sensing strategy due to high-fidelity estimates of local object geometry. However, existing algorithms for processing raw sensor inputs t…
Velocity Level Approximation of Pressure Field Contact Patches
Joseph Masterjohn, Damrong Guoy, John Shepherd +1
Pressure Field Contact (PFC) was recently introduced as a method for detailed modeling of contact interface regions at rates much faster than elasticity-theory models, while at the…