The wrench-closure workspace of parallel cable-driven mechanisms is the set of poses for which any wrench can be produced at the end-effector by a set of a non-negative cable tensions. It is already known that the boundary of the constant-orientation wrench-closure workspace of a planar parallel cable-driven mechanism is composed of segments of conic sections. Howevel; the relationship between ...

The paper deals with the problem of finding a form-closure fixturing of objects modeled with triangular meshes and considering as quality measure the maximum wrench that the object can resist in any direction. Although a triangular mesh is a polyhedral representation of the object, the number of faces is too large to allow a practical application of existing approaches for polyhedral objects, a...

This paper presents an approach to planning compliant grasps and fixtures in which the object exhibits minimal deflection under external disturbances. The approach, which applies to general twoand threedimensional grasps and fixtures represented by any quasirigid compliance model, employs a quality measure that characterizes the grasped or fixtured object’s worst-case deflection caused by distu...

The wrench feasibility and twist are the workspace conditions that indicate whether mobile-platform (MP) of cable-driven parallel robots (CDPRs) can provide a sufficient amount twist. Traditionally, these two quantities evaluated independently from actuator's torque speed limits, which assumed to be fixed in literature, but they are, indeed, coupled. This results conservative usage actuator cap...

introduction: some clinicians use a handheld screw driver instead of a torque wrench to definitively tighten abutment screws. the aim of this study was to compare the removal torque of one-piece and two-piece abutments tightened with a handheld driver and a torque control ratchet. methods: 40 iti implants were placed in acrylic blocks and divided into 4 groups. in groups one and two, 10 iti one...

The Naturally-Transitioning Rate-to-Force Controller (NTRFC) is presented for teleoperation of manipulators. Our goal is to provide a single controller which handles free motion, constrained motion, and the transition in-between without any artificial changes. In free motion the displacement of the master device (via the human operator’s hand) is proportional to the commanded Cartesian rate of ...

The Naturally-Transitioning Rate-to-Force Controller (NTRFC) is presented for remote teleoperation of manipulators. Our goal is to provide a single controller which handles free motion, constrained motion, and the transition in-between without any artificial changes. In free motion the displacement of the master device (via the human operator’s hand) is proportional to the commanded Cartesian r...