Force control and manipulation involving contacts are essentially hybrid control problems because of the inherent switching present in the dynamic behavior when the manipulator comes in contact with and leaves a surface. In this study, the game theoretic approach of hybrid control design is used to synthesize the least restrictive control law for a robotic manipulator to establish and maintain ...

The dynamic evolution with frictional contact of a viscoelastic body is considered. The assumptions on the functions used in modelling the contact are broad enough to include both the normal compliance and the Tresca models. The friction law uses a friction coefficient which is a non-monotone function of the slip. The existence and uniqueness of the solution are proved in the general three-dime...

We consider the equation that models the spreading of thin liquid films of power-law rheology. In particular, we analyze the existence and uniqueness of source-type self-similar solutions in planar and circular symmetries. We find that for shear-thinning fluids there exist a family of such solutions representing both finite and zero contact angle drops and that the solutions with zero contact a...

This paper deals with the mathematical modelling of the contact angle of a metal strip supported by periodically assembled rolls, as it is often the case in strip processing plants. The derivation of the governing differential equation is carried out by means of the calculus of variations for moving boundaries. An ideal-elastic-idealplastic material law of a periodic bending cycle is introduced...

In this paper, the dynamic analysis of the composite sandwich truncated conical shells (STCS) with various boundary conditions subjected to the low velocity impact was studied analytically, based on the higher order sandwich panel theory. The impact was assumed to occur normally over the top face-sheet, and the contact force history was predicted using two solution models of the motion which we...

Contact pressure measurements in total knee replacements are often made using a discrete sensor such as the Tekscan K-Scan sensor. However, no method currently exists for predicting the magnitude of sensor discretization errors in contact force, peak pressure, average pressure, and contact area, making it difficult to evaluate the accuracy of such measurements. This study identifies a non-dimen...

The nanoindentation experiment was carried out to estimate nanomechanical characteristics of polycarbonate polymer films. Hardness, effective elastic modulus and contact stress–strain rate curve were obtained. The results showed that the effective elastic modulus and the hardness decreased as the applied load was increased. As the hold time was increased, the effective elastic modulus and the h...

We propose a model-based control framework for multi-arm manipulation of a rigid object subject to external disturbances. The control framework, based on projected inverse dynamics, decomposes the control law into constrained and unconstrained subspaces. Unconstrained components accomplish the motion task with a desired 6-DOF Cartesian impedance behaviour against external disturbances. Meanwhil...

Earthquakes have been recognized as resulting from a stick-slip frictional instability along the faults between deformable rocks. An arbitrarily shaped contact element strategy, named as node-to-point contact element strategy, is proposed and applied with the static-explicit characters to handle the friction contact between deformable bodies with stick and finite frictional slip and extended he...

Datasets of online communication often take the form of contact sequences—ordered lists contacts (where a contact is defined as a triple of a sender, a recipient and a time). We propose measures of attractiveness and activity for such data sets and analyze these quantities for anonymized contact sequences from an Internet dating community. For this data set the attractiveness and activity measu...