Cornel Brisan

On the sonic composites without/with defects

The sound attenuation in a sonic composite without/with point defects is studied using a new method that combines the features of the cnoidal method and the genetic algorithm. Acoustic scatterers are composed by piezoceramic hollow spheres of functionally graded materials—the Reddy and cosine graded hollow spheres. This method enables to obtain the dispersion relation for defect modes, and the prediction of the evanescent nature of the modes inside the band-gaps.

A new class of sonic composites

Transformation acoustics opens a new avenue towards the architecture, modeling and simulation of a new class of sonic composites with scatterers made of various materials and having various shapes embedded in an epoxy matrix. The design of acoustic scatterers is based on the property of Helmholtz equations to be invariant under a coordinate transformation, i.e., a specific spatial compression is equivalent to a new material in a new space. In this paper, the noise suppression for a wide full band-gap of frequencies is discussed for spherical shell scatterers made of auxetic materials (materials with negative Poissons ratio). The original domain consists of spheres made from conventional foams with positive Poissons ratio. The spatial compression is controlled by the coordinate transformation, and leads to an equivalent domain filled with an auxetic material. The coordinate transformation is strongly supported by the manufacturing of auxetics which is based on the pore size reduction through radial compression molds.Transformation acoustics opens a new avenue towards the architecture, modeling and simulation of a new class of sonic composites with scatterers made of various materials and having various shapes embedded in an epoxy matrix. The design of acoustic scatterers is based on the property of Helmholtz equations to be invariant under a coordinate transformation, i.e., a specific spatial compression is equivalent to a new material in a new space. In this paper, the noise suppression for a wide full band-gap of frequencies is discussed for spherical shell scatterers made of auxetic materials (materials with negative Poissons ratio). The original domain consists of spheres made from conventional foams with positive Poissons ratio. The spatial compression is controlled by the coordinate transformation, and leads to an equivalent domain filled with an auxetic material. The coordinate transformation is strongly supported by the manufacturing of auxetics which is based on the pore size reduction through radial compr...

Dynamic and Interactive Path Planning and Collision Avoidance for an Industrial Robot Using Artificial Potential Field Based Method

In this paper the dynamic path planning with collision avoidance of an industrial robot is addressed. The Artificial Potential Field (APF) method is used and, as a contribution, it has been expanded with obstacle-charges having different geometrical forms in order to positively influence the generated trajectory. Also an analysis method is presented that ensures that no violation of a specified safety envelope can occur around the obstacles. Implementation of the theoretical consideration and experimental validation using industrial equipment is shown.

Aspects of Calibration and Control of PARTNER Robots

This paper presents basic elements concerning calibration and modular control of PARTNER robots which are used in the field of machine-tools. The advantages of this new kind of machine-tools consist on their reconfigurability, on the possibility to improve accuracy of those machines etc. The main point of the paper is that in the state of data which are coming from sensor system, those sent by a simulation model for control algorithm are used. It must be also remarked that the control algorithm is developed into modular manner, using mca2 software. The paper presents also numerical results obtained with the virtual models which were developed

Designing aspects of a special class of reconfigurable parallel robots

This paper presents basic elements concerning modeling and simulation of parallel robots which are used for machine-tools development. The advantages of this new kind of machine–tools consist on their reconfigurability, on the possibility to improve accuracy of those machines etc. The main point of the paper is that few variants of parallel mechanisms with only one mobile platform and with number of degrees of freedom between 3 and 6 were emphases. It must be also remarked that these variants are developed into modular manner in order to ensure full reconfigurability. The paper presents also numerical results obtained with the virtual models which were developed. Few prototypes which ere developed are also presented.

Virtual Models of Special Class of PARTNER Robots

This paper presents basic elements concerning modeling and simulation of parallel robots which are used for machine-tools development. The advantages of this new kind of machine-tools consist on their reconfigurability, on the possibility to improve accuracy of those machines etc. The main point of the paper is that few variants of parallel mechanisms with only one mobile platform and with number of degrees of freedom between 3 and 6 were emphases. It must be also remarked that these variants are developed into modular manner in order to ensure full reconfigurability. The paper presents also numerical results obtained with the virtual models which were developed

Optimal Design Concept of a Reconfigurable Haptic Device

Haptic devices are more and more common for human computer interaction or human machine interaction type applications. Using such devices multimodal interaction can be realized, increasing this way immersibility in the virtual reality environment. This paper presents specific considerations regarding the optimal design process of a class of reconfigurable haptic devices. The main focus of the paper is on the presentation of the novel ReHapy concept and on the details regarding the formulation of the cost function on which the optimal design process will be based.

Workspace Analysis of the 6 Degrees of Freedom PARTNER Parallel Robot

This paper presents a modular method to compute the workspace of parallel robot with 6 degrees of freedom. For the generation of the workspace also the mechanical constrains of both the active and passive joints are taken into consideration.

Extended Mobility Carried Out with a Double Hexapod Robot

The double hexapod robot consists in two staged hexapod platforms – Stewart Gough platforms - combining in a certain measure the advantages of the robots with parallel kinematics and of the serial robots: high accuracy, high stiffness, fast response and small dimensions, having an extended operating space. Different modelling and construction aspects were described in few previous articles. Some examples of trajectories generated with this positioning system are now presented to illustrate its mobility, as well as the workspaces for one and two hexapods in order to make possible a visual comparison between the two volumes.

The development of a pneumatically actuated driving simulator

This paper deals with the development of a Driving Simulator actuated by pneumatic muscles. So that the correct mechanical structure could be yielded, several investigations have been carried out, i.e. topology analyses, kinematic analysis and workspace investigations. Parallel platforms actuated by fluidic muscles represent an unusual design of driving simulators, with regard to weight aspects, which involves large potential of researching in many fields of mechatronics, mechanics and control.