The work presented here concerns the design and manufacturing possibility of a polymodular autonomous microrobot moving like an earthworm. The study consists of the development of a new locomotion actuator based on shape memory alloys. This actuator is formed by a flexible frame forced in post-buckling by its assembly on a rigid skeleton cage. This mechanical structure, forming a knot in the microrobot chain, uses its two post-buckling equilibrium positions to achieve first the support and second the local lengthening enabling the movement of the microrobot. Initially, we present the technical solution designed for the locomotion actuator and the mechanical characterization of its malleable structure. Then, we present the instrumentation by educated SMA of a malleable structure and the capability of microrobot locomotion task in a vertical tube.

In this paper a hybrid parallel-serial manipulator, named as CaHyMan (Cassino Hybrid Manipulator), is analyzed in term of stiffness characteristics as a specific example of a general procedure for analyzing stiffness of parallel-serial manipulators. A formulation is presented to deduce the stiffness matrix as a function of the most important stiffness and design parameters of the mechanical design. A formulation is proposed for a stiffness performance index by using the obtained stiffness matrix. A numerical investigation has been carried out on the effects of design parameters and fundamental results are discussed in the paper.

The purpose of this paper is in duplicate to present computer simulation results of concurrent grasp and object manipulation by a pair of three degrees of freedom (3-dof) robot fingers with rigid hemispherical finger-ends that induce rolling contacts with an object and propose a guidance of gain tuning. Although the existence of a class of sensory feedback signals that realize stable grasp and orientation control of the object concurrently has been shown theoretically, the problem of tuning of their feedback gains has not yet been solved. This paper proposes a guideline for tuning sensory feedback gains by deriving a relationship between the object mass and damping coefficients of finger motions through analyzing the overall fingers-object dynamics and taking into account the well-known force/velocity characteristics of human muscle in muscle physiology.

This paper describes emotion-based walking for a biped humanoid robot. In this paper, three emotions, such as happiness, sadness and anger are considered. These emotions are expressed by the walking styles of the biped humanoid robot that are preset by the parameterization of its whole body motion. To keep its balance during the emotional expressions, the motion of the trunk is employed which is calculated by the compensatory motion control based on the motions of the head, arms and legs. We have constructed a biped humanoid robot, WABIAB-RII (WAseda BIpedal humANoid robot-Revised II), to explore the issue of the emotional walking motion for a smooth and natural communication. WABIAN-RII has forty-three mechanical degrees of freedom and four passive degrees of freedom. Its height is about 1.84 m and its total weight is 127 kg. Using WABIAN-RII, three emotion expressions are experimented by the biped walking, including the body motion, and evaluated.

We present a new approach to termination analysis of numerical computations in logic programs. Traditional approaches fail to analyse them due to non well-foundedness of the integers. We present a technique that allows overcoming these difficulties. Our approach is based on transforming a program in a way that allows integrating and extending techniques originally developed for analysis of numerical computations in the framework of query-mapping pairs with the well-known framework of acceptability. Such an integration not only contributes to the understanding of termination behaviour of numerical computations, but also allows us to perform a correct analysis of such computations automatically, by extending previous work on a constraint-based approach to termination. Finally, we discuss possible extensions of the technique, including incorporating general term orderings.

The past decade has seen dramatic growth in the application of model checking techniques to the validation and verification of correctness properties of hardware, and more recently software systems. Recently, there has been increasing interest in applying logic programming techniques to model checking in particular and verification in general. For example, table-based logic programming can be used as an efficient means of performing explicit model checking. Other research has successfully exploited set-based logic program analysis, constraint logic programming, and logic program transformation techniques to verify systems.

A system is data-independent with respect to a data type $X$ iff the operations it can perform on values of type $X$ are restricted to just equality testing. The system may also store, input and output values of type $X$. We study model checking of systems which are data-independent with respect to two distinct type variables $X$ and $Y$, and may in addition use arrays with indices from $X$ and values from $Y$. Our main interest is the following parameterised model-checking problem: whether a given program satisfies a given temporal-logic formula for all non-empty finite instances of $X$ and $Y$. Initially, we consider instead the abstraction where $X$ and $Y$ are infinite and where partial functions with finite domains are used to model arrays. Using a translation to data-independent systems without arrays, we show that the $\mu$-calculus model-checking problem is decidable for these systems. From this result, we can deduce properties of all systems with finite instances of $X$ and $Y$. We show that there is a procedure for the above parameterised model-checking problem of the universal fragment of the $\mu$-calculus, such that it always terminates but may give false negatives. We also deduce that the parameterised model-checking problem of the universal disjunction-free fragment of the $\mu$-calculus is decidable. Practical motivations for model checking data-independent systems with arrays include verification of memory and cache systems, where $X$ is the type of memory addresses, and $Y$ the type of storable values. As an example we verify a fault-tolerant memory interface over a set of unreliable memories.

We propose an alternative way to represent graphs via OBDDs based on the observation that a partition of the graph nodes allows sharing among the employed OBDDs. In the second part of the paper we present a method to compute at the same time the quotient w.r.t. the maximum bisimulation and the OBDD representation of a given graph. The proposed computation is based on an OBDD-rewriting of the notion of Ackermann encoding of hereditarily finite sets into natural numbers.