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 deals with the controllability of biologically inspired snake-like mechanisms. Motion equations of the generic snake-like mechanism and investigations on its controllability lead to extremely complicated mathematical representations. The authors establish a physical analogy between the undulatory snake locomotion and object grasping. Based on this analogy, they propose a controllability criterion concerning the motion of the mobile mechanism. Results of dynamic simulations of the controlled system systematically point to the validity of the analogy-based controllability criterion. The purpose of this work is to achieve an understanding of the undulatory motion which constitutes the basis of a biologically motivated experimental setup.

The accuracy of pose of industrial robots is often unsatis-factory for advanced applications. Particularly regarding off-line programming, exchangeability and high precision tasks problems may occur which can be very time-consuming and costly to solve. Therefore a calibration system ROSY has been developed in order to increase the accuracy of standard robots and parallel-kinematic structures, like the Tricept robots.

This paper deals with the problem of the dynamic stress optimisation for manipulator robots. The maximum dynamic stress search is a challenging problem, insofar the dynamic stresses change in a very complex manner and they are strongly influenced by the payload, internal parameters of the robot, and instantaneous values of the articular variables (positions, velocities, and accelerations). This problem is solved using a hybrid simplex-genetic algorithm. This algorithm allows solving the dilemma of exploration vs. exploitation in the search space. A simulation study shows the greater performance of the proposed approach as compared to a classical approach of the configuration space inverse sweeping.

When modeling the dynamics of robotic systems containing electric motors, the force generated by the motor is generally considered only as an applied torque or force that is independent of mechanical state variables such as velocity. Due to the electromechanical coupling effects in the motors, this approach leads engineers working on a robotic system to designing faulty controllers. In this paper, we propose a dynamics analysis model in which DC motor dynamics are embedded into a mechanical dynamics model such that the electromechanical coupling effects are included in the overall model. A model for the DC motor is developed based on its equivalent circuit model and incorporated into the generalized recursive dynamics formula previously developed by our group. The resulting dynamic numerical simulation program provides an effective and realistic approach for analyzing the electromechanical dynamics of robotic systems driven by DC motors. The developed numerical simulation tool is evaluated by applying to an industrial robot and a flexible antenna system driven by DC motors for a satellite.

A survey of the field of control for flexible multi-link robots is presented. This research area has drawn great attention during the last two decades, and seems to be somewhat less “attractive” now, due to the many satisfactory results already obtained, but also because of the complex nature of the remaining open problems. Thus it seems that the time has come to try to deliver a sort of “state of the art” on this subject, although an exhaustive one is out of scope here, because of the great amount of publications. Instead, we survey the most salient progresses – in our opinion – approximately during the last decade, that are representative of the essential different ideas in the field. We proceed along with the exposition of material coming from about 119 included references. We do not pretend to deeply present each of the methods quoted hereafter; however, our goal is to briefly introduce most of the existing methods and to refer the interested reader to more detailed presentations for each scheme. To begin with, a now well-established classification of the flexible arms control goals is given. It is followed by a presentation of different control strategies, indicating in each case whether the approach deals with the one-link case, which can be successfully treated via linear models, or with the multi-link case which necessitates nonlinear, more complex, models. Some possible issues for future research are given in conclusion.

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.

The paper presents research on the APF approach for solving the GNRON and local minima problems. The repulsive potential function is modified in order to solve the GNRON problem. A simulated annealing algorithm integrated into the APF has solved the local minimum problem. The improved APF is applied to the path-planning problem of soccer robots. The simulated experiments show the validity of this approach.

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.

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.