Solid State Phenomena Vols. 166-167

Abstract: In this paper is presented a mini-system with compliant minigripper and piezoelectric actuation. The piezoelectric actuator is controlled with ramp and sinus signals. The response of the mini-system is predicted by the finite elements method. The displacement of the compliant mini-gripper and piezoactuator are analyzed. In the end is presented a comparison of the experimental results for same actuator but for two different types of the signals with theoretical results.

Abstract: This paper presents a practical approach for a distributed data acquisition system organized on several levels, with functions distributed in functional nodes. A field bus allows the communication between all programmable electronic modules for data acquisition (first level) and the process server (second level); the last one is a data processing and monitoring equipment which also represents the process server in a computer network with many clients. The electronic equipment for monitoring and recording analog and digital inputs (i.e. a functional node from the first level of the distributed data acquisition system) is described in detail. This equipment is organized around the PC/104 central unit and performs four main functions: acquisition, configuration, local monitoring and communication. The experimental results, corresponding to the Server application, are also presented and discussed in this paper.

Abstract: This paper discusses the inverse and forward kinematics problem for a 2-dof parallel robot with actuator redundancy. The reachable workspace of the robot is generated for a set of parameters and a solution for the actuators is proposed in the final.

Abstract: Self reconfiguring robots are complex robotic systems composed of a finite number of modules, where each module of the system is considered to be a simple agent. Based on this con¬text, the reconfi¬guration represents the process of re-arranging each agent of the robotic system in order to have a working system. One versatile method to determine the most adequate movement and reconfiguration algorithms can be done us¬ing modeling methods and tools. Using this approach, the control algorithms necessary to drive such a system can be modeled, tested and implemented in an embedded system much easier than in a classical approach. This paper presents the case of a self reconfiguring robot for which, a reconfiguration algorithm and a movement algorithm were determined, analyzed, tested and validated.

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 article, a new method for rapid tool movement in CNC machines is presented. Firstly, a single digital camera, installed on the Z-axis, captures the image of the workpiece on the work table. Image processing techniques, implemented using MATLAB, are then used to convert the image into a binary black and white image. This allows the locations of protruding edge sections on the workpiece, which could impede tool movement, to be identified. Quadtree decomposition is then performed on the binary image, and possible paths from the tool current location to its target location are found. These paths are then analysed based on the tool diameter clearance and the distance to the goal, and the shortest path with sufficient tool clearance is selected. A Visual Basic program then converts the selected path into G-code commands that provides instructions to the CNC machine tool such that this path is followed. With this method, the workpiece fixture location would not have to be precise as the imaging system would be able to automatically identify the target location with respect to the tool current location, along with the optimal path to reach it.

Abstract: Rural roads construction projects are expensive, this has led to difficulties in developing accurate construction plans and modeling the construction operation using a novel simulation system. In this field, the aim of this research is to create a knowledge driven rural road construction simulation system to assist satellite image in generating s and reliable road construction plans. Road construction operations of the resources have been identified, developed, classified and modeled through a comprehensive analysis of a Simulink road construction projects. For every road construction operation a GIS-based template for little models was defined and developed. The models abridge distance of the path on the roads construction between villages and automating the optimizing of works. Also, the models provide a roadmap for evaluating several shortest paths on road construction via Quad-tree decomposition of the satellite image. A simulation case study was modeled to identify applicability, usefulness and accuracy of the developed simulation system and results are presented in this paper. The study fulfilled that the system generated for fast marching.

Abstract: In this article, we used image processing by a webcam connected on top of the arm robot. The robot navigation is in an unknown environment. Then start point and target point were determined for the robot, so the robot needs to have a program for path planning using Voronoi diagrams to find the path. After the possible path for moving the robot was found, the route information obtained was sent to the arm robot. The arm robot moves in the workspace and any time new information was processed via the webcam. The program was written using MATLAB software which at controls the robot’s movement the unknown environment.

Abstract: Of all feasible designs, some are “better” than others. If this is assumed as true, then there must be some quality that the better designs have more of than the lees desirable ones do. This quality must be expressed as a computable function of the design variables, and it can consider optimizing to obtain a “best” design. The function with respect to which the design is optimized is called the objective function. In some design situations, there may appear to be two or more quantities which should be objective functions. The goal of the kinematics synthesis of the linkages is to establish the kinematics dimensions of the component elements provided that some conditions are imposed regarding movements of some points or elements. As a rule, only conditions about the positions of the points or elements are imposed. In the other words, only the transmission functions of the positions are used to write the synthesis equations. The solving of the kinematics synthesis problems is reduced to the solving of some nonlinear equation systems. As a result, the problems of the kinematics synthesis of linkages do not have the unique solutions. Only in some very simples particular cases the system of synthesis equations is linear and problem has a single solution. In the optimum synthesis of the gripper mechanisms, the objective function may express the positioning precision of the work pieces, the magnitude of the driving force, the domain of the stable fastening of the work pieces etc. In the work, some considerations about the optimum synthesis of the two fingered self centering grippers are shown.

Abstract: In this paper are described the main stages of structural and cinematic synthesis and analysis, design and functional simulation regarding the mechanism of the human hand prosthesis. For the structural scheme, one uses three pivot joints only, and one movement for closing the palm. The technical project is complete. One command scheme is shown too. The functional simulation has been made in CAD and virtual reality for to identify the best solutions and to optimize the constructive solution and to use the prosthesis by human operator.