To manipulate an object, we must simultaneously control the contact forces exerted on the object and the movements of our hand. Two alternative views for manipulation have been proposed: one in which motions and contact forces are represented and controlled by separate neural processes, and one in which motions and forces are controlled jointly, by a single process. To evaluate these alternativ...

Inverse dynamics analysis is commonly used to estimate the net loads at a joint during human motion. Most lower-limb models of movement represent the knee as a simple hinge joint when calculating muscle forces. This approach is limited because it neglects the contributions from tibiofemoral joint contact forces and may therefore lead to errors in estimated muscle forces. The aim of this study w...

During micro-assembly processes, surface forces influence the behavior of micro-objects more than volumic forces. Generally contacts happen between a microgripper and a micro-objet or a substrate and a micro-object. The pull-off force which represents the force required to break a contact is one of the predominant problem in micro-assembly. Now, current force measurements are mostly focused on ...

During micro-assembly processes, surface forces influence the behavior of micro-objects more than volumic forces. Generally contacts happen between a microgripper and a micro-objet or a substrate and a micro-object. The pull-off force which represents the force required to break a contact is one of the predominant problem in micro-assembly. Now, current force measurements are mostly focused on ...

Understanding degeneration of biological and prosthetic knee joints requires knowledge of the in-vivo loading environment during activities of daily living. Musculoskeletal models can estimate medial/lateral tibiofemoral compartment contact forces, yet anthropometric differences between individuals make accurate predictions challenging. We developed a full-body OpenSim musculoskeletal model wit...

The effect of increasing structural disorder on the distribution of contact forces P(f) inside three dimensional particle assemblies is systematically studied using computer simulations of model granular packings. Starting from a face-centered-cubic array, where all contact forces are identical, an increasing number of defects is introduced into the assembly, after which the system is then allo...

Most of the conventional approaches to mobile robot navigation avoid any kind of contact with the environment or with humans. However, most distance sensors have a limited field of view, so that collisions cannot be fully avoided in practical mobile robot applications. At the same time, direct physical contact also can be used as a means of intuitive communication between a robot and humans. We...

Revolute-jointed cobots depend on continuously variable transmissions (CVTs). CVTs constrain the speed ratio between two shafts to a particular value within a continuous range. The spherical CVT is well suited to cobots, but like other point contact transmissions, achieving good performance is challenging. We have studied the contact mechanics of the spherical CVT under certain simplifying assu...

A scenario for the yielding of granular matter is presented by considering the ensemble of force networks for a given contact network and applied shear stress tau. As tau is increased, the probability distribution of contact forces becomes highly anisotropic, the difference between average contact forces along minor and major axes grows, and the allowed networks span a shrinking subspace of all...