This paper deals with the problem of controlling contact forces in robotic manipulators with general kinematics. The main focus is on control of grasping contact forces exerted on the manipulated object. A visco{elastic model for contacts is adopted. The robustness of the decoupling controller with respect to the uncertainties a ecting system parameters is investigated. Su cient conditions for ...

Molecular dynamics simulations reveal that thermal-induced edge barriers and forces can govern the interlayer interaction of double walled carbon nanotubes. As a result, friction in such systems depends on both the area of contact and the length of the contact edges. The latter effect is negligible in macroscopic friction and provides a feasible explanation for the seemingly contradictory laws ...

Static grasping of a spherical object by two robot fingers is studied in this paper. The fingers may be rigid bodies or elastic beams, they may grasp the body with various orientation angles, and the tightening displacements may be linear or angular. Closed-form solutions for normal and tangential contact forces due to tightening displacements are obtained by solving compatibility equations, fo...

A dynamic simulation of threaded insertion is developed based on Euler's equations, impulsive forces, and a geometric description for threaded parts. Points of contact between the threaded parts are determined and tracked during the simulation. Reaction forces are computed based on the contact locations and the velocity constraints given by the kinematic description. The simulation will be used...

In this paper, we present algorithms to estimate external contact forces and joint torques using only skin, i.e. distributed tactile sensors. To deal with gaps between the tactile sensors (taxels), we use interpolation techniques. The application of these interpolation techniques allows us to estimate contact forces and joint torques without the need for expensive force-torque sensors. Validati...

A method based on mathematical programming is proposed for large deformation and contact analysis of cable networks. By explicitly considering these nonsmooth behaviors, we formulate the linear complementarity problems over symmetric cones under some practically acceptable assumptions. We also present the equivalent second-order cone programming (SOCP) problems, which can be regarded as the min...

The paper presents force-torque interpretations in intermediary telepresence for remote manipulation. Methods of reconstruction of force-torque data and algorithms to depict contact forces are presented in this paper. Real time force trajectory, the accuracy of the force trajectory and the state of the remote site in terms of wrench state are also described. In addition, options to take correct...

Assemblies of granular particles mechanically stable under their own weight contain arches. These are structural units identified as sets of mutually stable grains. It is generally assumed that these arches shield the weight above them and should bear most of the stress in the system. We test such hypothesis by studying the stress born by in-arch and out-of-arch grains. We show that, indeed, pa...

Abstract: This paper presents a new methodology for estimating wheel-ground contact normal forces, commonly known as vertical forces. The proposed method uses measurements from currently available standard sensors (accelerometers and relative suspension sensors). The aim of this study is to improve vehicle safety, especially to prevent rollover problems. One particular feature of the method is ...

A major requirement to design an implant is to develop our understanding of the applied internal forces during everyday activities. In the absence of any basic apparatus for measuring forces directly, it is essential to rely on modelling. The major aim of this study was therefore to understand the biomechanical function of subjects with the reversed anatomy Bayley-Walker prosthesis, using an in...