ANNALS OF THE UNIVERSITY OF CRAIOVA

Áron Ballagi, Tihamér Ádám

Abstract: This paper presents the fuzzy logic controller of an autonomous mobile robot which is a member of a cooperative robot team. The controller is implemented on TMS320F2812 DSP by Texas Instrument, which is one of the most efficient digital signal processor for control. The DSP is very good platform for complex control system implementation, where the real-time working is one of the most important and difficult process.
Keywords: Robotics, Fuzzy control, Digital signal processor.

Francisco J. Barrientos García, Isaac García Incertis, Félix Miguel Trespaderne, Eusebio de la Fuente López, José R. Perán González

Abstract: This paper describes the functioning of a manufacturing cell, in which several complex systems have been joined, such as: a robot, a computer vision system, and a lathe. To allow communication between these systems, diverse technologies have been used, varying from a field bus to the intranet of the company. The robot takes the role of master, coordinating the functioning of the rest of subsystems. The cell is endowed with the possibility of remote adjustment and monitoring across the company’s Intranet. The cell’s functioning conditions can be modified from the laboratory, to assure that the pieces made are within the quality limits specified by the clients. Copyright CARTIF 2005.
Keywords: Fieldbus, communications, computer vision, architecture.

Bîzdoaca Nicu-George, Degeratu Sonia, Diaconu Ilie, Bîzdoaca Elvira, Petrisor Anca, Pana Patrascu Daniela

Abstract: This paper propose a strategy for autonomous navigation of field mobile robots using behaviour based control. The premise of the proposed approach is to embed the human expert's heuristic knowledge into the mobile robot navigation strategy using fuzzy logic tools. The robot navigation strategy developed here is comprised of simple, independent behaviours. The recommendations from these behaviours are combined with appropriate weighting factors to yield an autonomous navigation strategy for the mobile robot that requires no a priori information about the environment.
Keywords: robotics, demining robot, behaviour based control, fuzzy logic, landmine search strategy.

Dorian Cojocaru, Raluca Vidican, Bogdan Pruna

Abstract: This paper presents an application regarding face recognition. The first task, the detection, is accomplished using color information. The second task, the identification of a detected face, uses the component analysis method called eigenfaces approch. The experiment is implemented in a Matlab aplication which consists in two image processing steps. First the person’s head is separated from the background and then the recognition is performed by comparing characteristics of the face to those of known individuals.
Keywords: computer vision, image processing, face detection, face recognition.

Ciprian Comsa, Robert Mitrica, Mircea Nitulescu, Gabriel Vladut

Abstract: In the technological field, virtual reality technology has been widely proposed and recognized as a major technological advance for supporting life-long education to individuals along with a flexible workforce. One of the unique capabilities of the VR technology is the successful translation of abstract concepts into visualized events and the interaction of students with them, that in real life could be limited due to distance, time, and safety factors. This paper presents a virtual laboratory ViReC accessible through the Internet. The architecture uses open standards, such as World Wide Web and its related technologies: HTTP, HTML, Java, Macromedia Flash, PHP, MySQL and so on.
Keywords: Virtual robotics, Virtual laboratory, E-learning, Internet solutions.

Ionut Dinulescu, Dorin Popescu, Gabriel Terejanu, Andras Marinescu

Abstract: The aim of the work was to develop the hardware and software structures to be used in an e-teaching context. A web based application has been developed, which allows tele-programming a PLC device via Internet. The main requirement of this application is to provide a friendly user interface that allows PLC application developers to control the devices from anywhere in the world via a thin client that does not need the installation of any additional software on the user side. After considering several alternatives, it has been opted for web based open-source technologies that considerably reduced the implementation costs while accomplishing the other project requirements.
Keywords: telematics, web based application, programmable logic controller, opensource technologies.

Mircea Ivanescu, Dorian Cojocaru, Nirvana Popescu, Decebal Popescu, Razvan Tudor Tanasie

Abstract: The control problem of a hyperredundant manipulator by using a robust 3 D visual servoing is presented. The theoretical model of this class of arms is studied. Servoing is based on binocular vision obtained by two cameras that ensure a continuous measure of the arm parameters. The control errors function is built in 3D cartesian space by the visual information obtained in the two image planes. The 2D errors are determined as the shape errors, they are calculated on the differences between the actual and desired continuous angle values. A spatial error is determined and a control law is discussed. The stability of the closed-loop control system is proven. Computer simulations are presented to show the applicability of the method.
Keywords: hyperredundant manipulator, visual servoing, distributed parameter system.

Larissa Labakhua, Urbano Nunes, Rui Rodrigues, Fatima Leite

Abstract: A fleet of small individual electric vehicles, which can run automatically without direct human intervention, could be a solution for the downtown transportation. For this kind of vehicles it will be necessary an effective trajectory planning method, to ensure the mobility with safety and comfort. In this paper three trajectory planning methods are analysed from the point of view of passengers' comfort, implementation facility, and trajectory tracking.
Keywords: Trajectory planning, Splines, Curves, Controller, Vehicle simulation.

Corneliu Lazar, Eugen Casandra and Alin Lungu

Abstract: The paper concentrates on detection of motion from 2D image sequences and the image analysis used to extract feature points. It is considered a still camera with constant background and a moving object. Object moving across the background will generate changes of its feature points. Detection of these points is used to recover the trajectory of the moving object. The developed procedure for motion recovery was tested to detect the moving of a robot end-effector and real-time experimental results demonstrate the efficiency of the method.
Keywords: Motion recovery, Interesting point, Interest operator, Motion trajectory, Motion field

Gheorghe LAZEA, Radu ROBOTIN, Sorin HERLE, Florin COTOFAN

Abstract: This paper describes a version of D* algorithm with focusing heuristic for mobile robot path planning in dynamic environments. The aim is to determine the optimal path to the target using a map able to reflect the changes in the environment, detected using the sensors system. The optimality of the trajectory may be considered from path length point of view, time required to reach the goal position, or energy consumption.
Keywords: mobile robot, path planning, navigation algorithm, focusing heuristic.

Mircea Nitulescu

Abstract: In industry, the mobile robots can operate as automatic handling devices with extensive flexibility. A control solution for the driven wheel autonomous mobile robot operating in well-structured environments is analyzed in this paper. The path is stored in the memory and given by a global path planner generator as a set of basic and predefined elements. The onboard navigation system includes an error-feedback controller which ensures that the errors between the measured and reference states are small and a mobile robot location sensing using odometry.
Keywords: Mobile robot, Modeling, Control design, Navigation

Doru Panescu, Sorin Miron

Abstract: Some results of a research concerning multi-robot system planning are presented. The environment is an industrial one with mobile robots in charge with part transferring. The proposed approach is based on multiagent systems, the contract net protocol being used to solve the co-ordination problem. Some details are given regarding the design and implementation that refer to using CLIPS as software environment, with benefits got by combining rules and objects.
Keywords: mobile robots, co-ordination, multiagent systems, rule-based programming, object-oriented programming.

Patrascu Pana Daniela, Bîzdoaca Nicu, Pana Cristina

Abstract: The control problem using artificial potentials is analised for two cases: first case we’ll consider that the redundant manipulator moves without restriction in a free-obstacle workspace, and in the second one the redundant manipulator moves in a workspace with obstacles. Numerical simulation for 3D model are presented in order to emphse the eficiency of the method.
Keywords: redundant manipulators, obstacle avoidance, artificial potential method, dynamic control.

Dorina Purcaru, Elena Niculescu

Abstract: The shape recognition based on the region of the accepted tolerance is recommended when only certain recognition or a rejection of the analyzed shape must be obtained. The vector of the characteristic parameters describes each model and results by processing many imprints of a known shape. The model and tolerance set (the maximum accepted deviations of the parameter values) definitions affect the size of the region of the accepted tolerance and the decision of the recognition process. If an unknown shape is inside the region of the accepted tolerance associated to a model, that unknown shape is identified with the model.
Keywords: shapes, models, parameters, characteristic vector, shape description, distance, regions, tolerance, recognition.