In this work a general partitioning of logic control design strategies into two main approaches, cooperative and hierarchical, is proposed and some lines for a comparison are drawn. In the authors' opinion, the cooperative approach basically collects methods inspired by IEC 61499 and agent paradigms while, the hierarchical approach, generally collects design procedures inspired by IEC 61131. Among the elements of the latter category, particular attention is devoted to the design methodology based on the Generalized Actuator framework, recently proposed by the authors. A case-study is considered to derive some starting considerations on the properties of the considered approaches.

Two techniques for slip detection with a rubber-based tactile matrix sensor are presented. The described results have been obtained within a common research activity between the Robotics and Automation Laboratory of the University of Bologna and the Control Laboratory of the Delft University of Technology. The first technique is based on a frequency analysis of the position of the center of force distribution. The main idea is that before a slip situation actually occurs, it is possible to detect a micro movement of the object due to the elasticity of the rubber. By implementing a FFT of the center of distribution and by testing the frequency components, the slip is identified before it practically occurs. The second approach is based on the principle that the normal forces measured by the tactile sensor fluctuate with a certain frequency during slip because of the rubber elasticity. This fluctuation is due to a 'catch and snap back' effect, which is present when an object is slipping over the sensor's surface. By testing the frequency domain of the normal force a slip condition can be detected. A comparison of the two approaches is presented and discussed on the basis of experimental results obtained in both laboratories.

This paper demonstrates fundamental problems with dexterity measures found throughout the robotics literature and offers a methodology for correcting those problems. Measures of robot dexterity derived from eigenvalues, eigenvectors, similarity transformations, singular-value decompositions and the Moore-Penrose inverse of the manipulator Jacobian do not have invariant physical meaning. The paper presents manipulability ellipsoids and manipulability screw-subspaces for both redundant and nonredundant manipulators.>