Papers by Author: Sergiu Dan Stan

Abstract: The different interests of the two populations towards recyclable waste led to a different scenario: in Romania all types of WEEE have been collected since its entrance into the EU; in China the ‘‘interest’’ in recycling is typically related to large household appliances, with a secondary role are the regulations covering three major issues, namely, take-back issues, controls on hazardous substances in WEEE and the assurance of good environmental management in WEEE plants. Keywords: WEEE, Collection, Recycling, Regulation, Consumption

Abstract: The accuracy of outer space robotic applications using haptic devices requires high performance of the haptic device connected with the remote robot. The paper introduces and develops a quality indicator system, able to give overall information on the performances of the haptic device. The authors define several categories of indicators, such as the geometric, kinematic and dynamic. The geometric category comprises the position and orientation accuracy, the repeatability, the trajectory fluctuation, the resolution, the working space and the static relaxation. The kinematic indicators category comprises the speed fluctuation, the maximal acceleration and time accuracy. The dynamic indicators category comprises the force and torque fluctuation, the vibration amplitude and acceleration. All above-mentioned simple indicators open the path to complex indicators such as the pose accuracy in relation with the working space or the maximum force/torque in respect with the total weight. By introducing moderated indicators, the authors consider the specificity of each group of tasks or applications and in the end, they introduce a global moderated indicator in order to quantify rapidly the general performance level of a certain haptic device.

Abstract: The paper presents a comparative dynamic modeling and VR (virtual reality) simulation for two 3 DOF medical parallel robots: a three coupled motions structure (Orthoglide robot) versus two coupled motion parallel structure (robot of type 1PRRR+2PRPaR). Kinematical and dynamical models, followed by a VR application with control aspects are presented for these two parallel robots. The innovative user interface for high-level control of the two parallel robots, presented in the paper, was developed in MATLAB - Simulink and SimMechanics environment, while the closed form dynamic models were obtained in MAPLE program. This kind of parallel robots can be successfully applied for medical applications where accuracy and high dynamic behavior are required. This research will lay a good foundation for the development of medical parallel robots.

Abstract: In this paper a new method for determination and optimization of the workspace of parallel manipulators is presented. The proposed method is based on a geometrical approach, and offers the possibility to generate automatically the workspace in a CAD environment. Thus, the relationship between the geometrical design parameters of the parallel manipulator and its workspace can be analyzed without difficulty. Optimization problem considered in this paper consists in determining the dimensions of a parallel manipulator having the closest workspace to a prescribed task region. Finally, numerical applications of two types of planar parallel manipulators are presented in order to illustrate the proposed approach.