In a cable-driven parallel robot, elastic cables are used to manipulate the end effector within the workspace. Cable force measurement is necessary for several control algorithms like cable force control, contact control, or load identification. The cable force sensor can be placed directly at the connection point on the platform or somewhere along the cable using pulleys. The pulleys between the force sensor and the platform disturb the force measurement accuracy due to friction. This paper deals with modeling and compensation of the friction. The friction behavior in the drive train with focus on the effects of the pulleys is non-trivial, as the cable movement consists of microscopic and macroscopic movements and standstills. Friction models from Coulomb and Dahl are adapted to deal with the pulley friction. The experimental evaluation showed an improvement of 70% with respect to the uncompensated case.

In this paper a novel hierarchical DfT methodology is presented which is targeted to improve the delay fault testability for external testing and scan based BIST. After the partitioning of the design into high frequency macros, the analysis for delay fault testability already starts in parallel with the implementation at the macro level. A specification is generated for each macro that defines the delay fault testing characteristics at the macro boundaries. This specification is used to analyse and improve the delay fault testability by improving the scan chain ordering at macro-level before the macros are connected together into the total chip network. The hierarchical methodology has been evaluated with the instruction window buffer core of an out-of-order processor. It was shown that for this design practically no extra hardware is required.

This paper discusses a grasp scheme for a pyramidal-like object placed on a table under the gravitational field. We assume that the contact friction is small enough to ensure that any direct grasp fails in achieving an equilibrium grasp. For an idealized 2D triangle object placed vertically on a table, we first show that a planar two-fingered hand can always achieve an equilibrium grasp under frictional contact. We also extend the basic idea to a polyhedron whose face is triangle and show two possible procedures leading to equilibrium grasps. Finally, we verify our idea experimentally for the polyhedra.

This paper discusses how many fingers are necessary and sufficient for capturing a pyramidal-like object placed on a table under the gravitational field. Allowing that the contact friction is small enough to ensure that any direct grasp may fail in achieving an equilibrium grasp, we prove that a planar two-fingered hand are necessary and sufficient for achieving the task for an idealized 2D triangle object placed vertically on a table. We also consider 3D pyramidal-like objects, and prove that a spatial two-fingered hand are necessary and sufficient for achieving the task.