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Robots
Kinds of Robots Selected AbstractsA Fast Stereo Matching Algorithm for Sewer Inspection RobotsIEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING, Issue 4 2008Alireza Ahrary Non-member Abstract In this paper, we present a fast stereo matching algorithm for sewer inspection robots. Conventional algorithms such as the sum of squared difference (SSD) and cross-correlation based on segmentation, graph cuts and so on have been proposed. However, most of them are computationally expensive. In order to solve the problem, we propose a fast stereo matching algorithm using interpolation in this paper. In our algorithm, an image is initially divided into many blocks. Then, a matching measure combining SSD and the cross-correlation is calculated only at the corner points of each block. A down sampled sewer disparity image is composed of only the corner points. Because the disparities change continuously in the sewer environment, we use the cubic interpolation for extending the down sampled sewer disparity image into a regular-sized disparity image. The experimental results show that our algorithm outperforms the conventional algorithms in both accuracy and speed in the sewer environment. © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [source] Shared challenges in object perception for robots and infantsINFANT AND CHILD DEVELOPMENT, Issue 1 2008Paul Fitzpatrick Abstract Robots and humans receive partial, fragmentary hints about the world's state through their respective sensors. These hints,tiny patches of light intensity, frequency components of sound, etc.,are far removed from the world of objects which we feel and perceive so effortlessly around us. The study of infant development and the construction of robots are both deeply concerned with how this apparent gap between the world and our experience of it is bridged. In this paper, we focus on some fundamental problems in perception which have attracted the attention of researchers in both robotics and infant development. Our goal was to identify points of contact already existing between the two fields, and also important questions identified in one field that could fruitfully be addressed in the other. We start with the problem of object segregation: how do infants and robots determine visually where one object ends and another begins? For object segregation, both the fields have examined the idea of using ,key events' where perception is in some way simplified and the infant or robot acquires knowledge that can be exploited at other times. We propose that the identification of the key events themselves constitutes a point of contact between the fields. Although the specific algorithms used in robots do not necessarily map directly to infant strategies, the overall ,algorithmic skeleton' formed by the set of algorithms needed to identify and exploit key events may in fact form the basis for mutual dialogue. We then look more broadly at the role of embodiment in humans and robots, and see the opportunities it affords for development. Copyright © 2008 John Wiley & Sons, Ltd. [source] Autonomous off-road navigation with end-to-end learning for the LAGR programJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 1 2009Max Bajracharya We describe a fully integrated real-time system for autonomous off-road navigation that uses end-to-end learning from onboard proprioceptive sensors, operator input, and stereo cameras to adapt to local terrain and extend terrain classification into the far field to avoid myopic behavior. The system consists of two learning algorithms: a short-range, geometry-based local terrain classifier that learns from very few proprioceptive examples and is robust in many off-road environments; and a long-range, image-based classifier that learns from geometry-based classification and continuously generalizes geometry to appearance, making it effective even in complex terrain and varying lighting conditions. In addition to presenting the learning algorithms, we describe the system architecture and results from the Learning Applied to Ground Robots (LAGR) program's field tests. © 2008 Wiley Periodicals, Inc. [source] Biologically inspired climbing with a hexapedal robotJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 4-5 2008M. J. Spenko This paper presents an integrated, systems-level view of several novel design and control features associated with the biologically inspired, hexapedal, RiSE (Robots in Scansorial Environments) robot. RiSE is the first legged machine capable of locomotion on both the ground and a variety of vertical building surfaces including brick, stucco, and crushed stone at speeds up to 4 cm/s, quietly and without the use of suction, magnets, or adhesives. It achieves these capabilities through a combination of bioinspired and traditional design methods. This paper describes the design process and specifically addresses body morphology, hierarchical compliance in the legs and feet, and sensing and control systems that enable robust and reliable climbing on difficult surfaces. Experimental results illustrate the effects of various behaviors on climbing performance and demonstrate the robot's ability to climb reliably for long distances. © 2008 Wiley Periodicals, Inc. [source] Evolution and field performance of a rescue robotJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 1-2 2008Mark J. Micire Robots are slowly finding their way into the hands of search and rescue groups. One of the robots contributing to this effort is the Inuktun VGTV-Xtreme series by American Standard Robotics. This capable robot is one of the only robots engineered specifically for the search and rescue domain. This paper describes the adaptation of the VGTV platform from an industrial inspection robot into a capable and versatile search and rescue robot. These adaptations were based on growing requirements established by rescue groups, academic research, and extensive field trials. A narrative description of a successful search of a damaged building during the aftermath of Hurricane Katrina is included to support these claims. Finally, lessons learned from these deployments and guidelines for future robot development is discussed. © 2008 Wiley Periodicals, Inc. [source] Analyzing unidentified locked-joint failures in kinematically redundant manipulatorsJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 1 2005Manish Goel Robots are frequently used for operations in hostile environments. The very nature of these environments, however, increases the likelihood of robot failures. Common failure-tolerance techniques rely on effective failure detection and identification. Since a failure may not always be successfully identified, or, even if identified, may not be identified soon enough, it becomes important to consider the behavior of manipulators with unidentified failures. This work investigates the behavior of robots experiencing unidentified locked-joint failures in a general class of tasks characterized by point-to-point motion. Based on the analysis, a procedure for workspace evaluation is developed that allows for the identification of regions in the manipulator's workspace in which tasks may be completed even with such failures. © 2005 Wiley Periodicals, Inc. [source] Optimal Velocity Planning of Wheeled Mobile Robots on Specific Paths in Static and Dynamic EnvironmentsJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 12 2003María Prado This paper deals with optimal temporal-planning of wheeled mobile robots (WMRs) when navigating on predefined spatial paths. A method is proposed to generate a time-optimal velocity profile for any spatial path in static environments or when mobile obstacles are present. The method generates a feasible trajectory to be tracked by fully exploiting velocity, acceleration and deceleration boundaries of the WMR, and by ensuring the continuity of the velocity and acceleration functions. As an additional benefit for the tracking process the jerk is also bounded. The algorithm is not time consuming, since it mostly uses closed mathematical expressions, nonetheless iteration strategies are presented to solve specific situations. However, such situations are not expected to occur when the spatial paths are planned as smooth curves. The success of the algorithm was tested by experimental and simulation results on the WMR "RAM." © 2003 Wiley Periodicals, Inc. [source] Neural Networks Based Control of Mobile Robots: Development and Experimental ValidationJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 10 2003M. L. Corradini The paper proposes a neural networks approach to the solution of the tracking problem for mobile robots. Neural networks based controllers are investigated in order to exploit the nonlinear approximation capabilities of the nets for modeling the kinematic behavior of the vehicle and for reducing unmodeled tracking errors contributions. The training of the nets and the control performances analysis have been done in a real experimental setup. The proposed solutions are implemented on a PC-based control architecture for the real-time control of the LabMate mobile base and are compared with classical kinematic control schemes. Experimental results are satisfactory in terms of tracking errors and computational efforts. © 2003 Wiley Periodicals, Inc. [source] Dynamic Feedback Control of XYnR, Planar Robots with n Rotational Passive JointsJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 5 2003Stefano Iannitti We consider the problem of trajectory planning and control for an XYnR, Planar robot with the first two joints (rotational or prismatic) actuated and n rotational passive joints, moving both in the presence and the absence of gravity. Under the assumption that each passive link is attached at the center of percussion of the previous passive link, dynamics of the system can be expressed through the behavior of n special points of the plane. These points are called link-related acceleration points (LRAP) since their instantaneous acceleration is oriented as the axis of the related passive links. Moreover, LRAP dynamics present a backward recursive form which can be exploited to recursively design a dynamic feedback that completely linearizes the system equations. We use this approach to solve trajectory planning and tracking problems and report simulation results obtained for an RR2R, robot having the first two rotational joints actuated. © 2003 Wiley Periodicals, Inc. [source] High-throughput operation of sample-exchange robots with double tongs at the Photon Factory beamlinesJOURNAL OF SYNCHROTRON RADIATION, Issue 3 2008Masahiko Hiraki Sample-exchange robots that can exchange cryo-pins bearing protein crystals out of experimental hutches according to user instructions have been developed. The robots were designed based on the SAM (Stanford Synchrotron Research Laboratory automated mounting) system. In order to reduce the time required for the sample exchange, the single tongs of the SAM system were modified and a double-tongs system that can hold two cryo-pins at the same time was developed. Robots with double tongs can move to the goniometer head holding the next cryo-pin with one set of tongs, dismount the experimented cryo-pin with the other set, and then mount the next pin onto the goniometer head without leaving the diffractometer area. Two different types of tongs have been installed: single tongs at beamlines BL-5A and AR-NW12A, and a double-tongs system at beamline BL-17A of the Photon Factory. The same graphical user interface software for operation of the sample-exchange robots is used at all beamlines, however, so that users do not need to consider differences between the systems. In a trial, the robot with double tongs could exchange samples within 10,s. [source] Robotics in cardiac surgery: the Istanbul experienceTHE INTERNATIONAL JOURNAL OF MEDICAL ROBOTICS AND COMPUTER ASSISTED SURGERY, Issue 2 2006Ertan Sagbas Abstract Background Robots are sensor-based tools capable of performing precise, accurate and versatile actions. Initially designed to spare humans from risky tasks, robots have progressed into revolutionary tools for surgeons. Tele-operated robots, such as the da VinciÔ (Intuitive Surgical, Mountain View, CA), have allowed cardiac procedures to start benefiting from robotics as an enhancement to traditional minimally invasive surgery. Methods The aim of this text was to discuss our experience with the da Vinci system during a 12 month period in which 61 cardiac patients were operated on. There were 59 coronary bypass patients (CABG) and two atrial septal defect (ASD) closures. Results Two patients (3.3%) had to be converted to median sternotomy because of pleural adhesions. There were no procedure- or device-related complications. Conclusion Our experience suggests that robotics can be integrated into routine cardiac surgical practice. Systematic training, team dedication and proper patient selection are important factors that determine the success of a robotic surgery programme. Copyright © 2006 John Wiley & Sons, Ltd. [source] Architectural Methodology Based on Intentional Configuration of BehaviorsCOMPUTATIONAL INTELLIGENCE, Issue 1 2001François Michaud Intelligence has been an object of study for a long time. Different architectures try to capture and reproduce these aspects into artificial systems (or agents), but there is still no agreement on how to integrate them into a general framework. With this objective in mind, we propose an architectural methodology based on the idea of intentional configuration of behaviors. Behavior-producing modules are used as basic control components that are selected and modified dynamically according to the intentions of the agent. These intentions are influenced by the situation perceived, knowledge about the world, and internal variables that monitor the state of the agent. The architectural methodology preserves the emergence of functionality associated with the behavior-based paradigm in the more abstract levels involved in configuring the behaviors. Validation of this architecture is done using a simulated world for mobile robots, in which the agent must deal with various goals such as managing its energy and its well-being, finding targets, and acquiring knowledge about its environment. Fuzzy logic, a topologic map learning algorithm, and activation variables with a propagation mechanism are used to implement the architecture for this agent. [source] Real-time deadlock-free navigation for multiple mobile robotsELECTRICAL ENGINEERING IN JAPAN, Issue 3 2008Harunori Gakuhari Abstract This paper proposes a practicable navigation method for multiple mobile robots in a realistic environment. In the past, many navigation methods have been developed. However, they were often limited to a single robot and sometimes assumed robots with special mobility such as holonomic ones. From the viewpoint of practical applications it is indispensable that the number of robots is arbitrary and a general shape and mobility for them is allowed. In this study, deadlock-free navigation for nonholonomic mobile robots in a practical environment is given. In the proposed scheme, states of the environment and robots are fed back in real time, and global path planning is cyclically executed. This enables an adaptation to a changing environment and reliable, deadlock-free navigation for multiple robots. The real-time online path planning is performed by an efficient A* search in Configuration Spaces representing the robots and environment. The proposed method is tested in several simulations which represent typical complicated navigation situations. As a result, the effectiveness of the method is verified. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 163(3): 27, 36, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20714 [source] Behavior selection of mobile robot based on integration of multimodal informationELECTRICAL ENGINEERING IN JAPAN, Issue 2 2007Bin Chen Abstract Recently, biologically inspired robots have been developed to acquire the capacity for directing visual attention to salient stimulus generated from the audiovisual environment. For the purpose of realizing this behavior, a general method is to calculate saliency maps to represent how much the external information attracts the robot's visual attention, where the audiovisual information and robot's motion status should be involved. In this paper, we represent a visual attention model where three modalities,audio information, visual information, and robot's motor status,are considered, because previous research has not considered all of them. First, we introduce a 2D density map, on which the value denotes how much the robot pays attention to each spatial location. Then we model the attention density using a Bayesian network where the robot's motion statuses are involved. Next, the information from both audio and visual modalities is integrated with the attention density map in integrate-fire neurons. The robot can direct its attention to the locations where the integrate-fire neurons are fired. Finally, the visual attention model is applied to make the robot select the visual information from the environment, and react to the content selected. Experimental results show that it is possible for robots to acquire the visual information related to their behaviors by using the attention model considering motion statuses. The robot can select its behaviors to adapt to the dynamic environment as well as to switch to another task according to the recognition results of visual attention. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 158(2): 39,48, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20335 [source] Attitude control of planar end-effector and estimation of contact point using parallel mechanismELECTRONICS & COMMUNICATIONS IN JAPAN, Issue 3 2008Ryogo Kubo Abstract Recently, may robots have been utilized in unknown environment, for example, slave robots of teleoperation systems, walking robots and so on. They are called environment-adaptive robots. It is very important for the environment-adaptive robots to contact stably and to recognize unknown environment. In this paper, a compliance controller of attitude of a planar end-effector is proposed to achieve stable contact with unknown environment. The robot utilized in this research has parallel mechanism as a whole, since the planar end-effector is supported by three arms. With the assumption that only face-to-point contact exists between the end-effector and unknown environment, an estimation method of the contact point without sensors is also proposed. Moreover, excessive stress is not exerted on the robots and the environments by means of the controller we propose, when the contact point is estimated. Our new approach of contact motion can be widely applied to the robots using parallel mechanism. The validity of the proposed method is shown by the numerical and experimental results. © 2008 Wiley Periodicals, Inc. Electron Comm Jpn, 91(3): 28, 36, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10071 [source] Rule,based reasoning and neural network perception for safe off,road robot mobilityEXPERT SYSTEMS, Issue 4 2002Edward Tunstel Operational safety and health monitoring are critical matters for autonomous field mobile robots such as planetary rovers operating on challenging terrain. This paper describes relevant rover safety and health issues and presents an approach to maintaining vehicle safety in a mobility and navigation context. The proposed rover safety module is composed of two distinct components: safe attitude (pitch and roll) management and safe traction management. Fuzzy logic approaches to reasoning about safe attitude and traction management are presented, wherein inertial sensing of safety status and vision,based neural network perception of terrain quality are used to infer safe speeds of traversal. Results of initial field tests and laboratory experiments are also described. The approach provides an intrinsic safety cognizance and a capacity for reactive mitigation of robot mobility and navigation risks. [source] Ergonomics considerations and management action in the implementation of industrial robotsHUMAN FACTORS AND ERGONOMICS IN MANUFACTURING & SERVICE INDUSTRIES, Issue 3 2001Biman Das To obtain maximum benefit from the implementation of industrial robots, it is necessary to identify specific ergonomics problems and provide answers to such problems. Special features of a typical industrial robot are described. Specific ergonomics problems are identified and discussed: sociopsychological factors, systems safety design, communications, training, and workplace design. For the successful implementation of industrial robots, management should take timely action with regard to advanced planning procedures, user involvement plans, communication channels, company labor policies, and continuous training programs. The technological change from conventional to advanced manufacturing, such as industrial robots, must be jointly supported by all levels of management and workers. © 2001 John Wiley & Sons, Inc. [source] Solar power for an Antarctic roverHYDROLOGICAL PROCESSES, Issue 4 2006J. H. Lever Abstract Sensors mounted on mobile robots could serve a variety of science missions in Antarctica. Although weather conditions can be harsh, Antarctic snowfields offer unique conditions to facilitate long-distance robot deployment: the absence of obstacles, firm snow with high albedo, and 24 h sunlight during the summer. We have developed a four-wheel-drive, solar-powered rover that capitalizes on these advantages. Analyses and field measurements confirm that solar power reflected from Antarctic snow contributes 30,40% of the power available to a robot consisting of a five-side box of solar panels. Mobility analyses indicate that the 80 kg rover can move at 0·8 m s,1 during clear sky conditions on firm snow into a 5 m s,1 headwind, twice the speed needed to achieve the design target of 500 km in 2 weeks. Local winter tests of the chassis demonstrated good grade-climbing ability and lower than predicted rolling resistance. Tests of the completed robot occurred in Greenland in 2005. Copyright © 2006 John Wiley & Sons, Ltd. [source] Haptic motion control for physical human supportIEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING, Issue 2 2009Tomoyuki Shimono Member Abstract Future robots and mechatronic systems will be required to physically support human activities. In order to reach the stage of real human-friendly physical support, they should acquire many functions such as the recognition of the real world based on complicated human actions, the transmission of the ambient information in harmony with human sensation, and so on. Since haptic sensation, as well as visual information and auditory sensation are so important for human activities, haptic motion control is one of the most important issues for the purpose. This paper now presents some haptic motion control techniques as the fundamental technology for the realization of future physical human support. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [source] A Fast Stereo Matching Algorithm for Sewer Inspection RobotsIEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING, Issue 4 2008Alireza Ahrary Non-member Abstract In this paper, we present a fast stereo matching algorithm for sewer inspection robots. Conventional algorithms such as the sum of squared difference (SSD) and cross-correlation based on segmentation, graph cuts and so on have been proposed. However, most of them are computationally expensive. In order to solve the problem, we propose a fast stereo matching algorithm using interpolation in this paper. In our algorithm, an image is initially divided into many blocks. Then, a matching measure combining SSD and the cross-correlation is calculated only at the corner points of each block. A down sampled sewer disparity image is composed of only the corner points. Because the disparities change continuously in the sewer environment, we use the cubic interpolation for extending the down sampled sewer disparity image into a regular-sized disparity image. The experimental results show that our algorithm outperforms the conventional algorithms in both accuracy and speed in the sewer environment. © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [source] Shared challenges in object perception for robots and infantsINFANT AND CHILD DEVELOPMENT, Issue 1 2008Paul Fitzpatrick Abstract Robots and humans receive partial, fragmentary hints about the world's state through their respective sensors. These hints,tiny patches of light intensity, frequency components of sound, etc.,are far removed from the world of objects which we feel and perceive so effortlessly around us. The study of infant development and the construction of robots are both deeply concerned with how this apparent gap between the world and our experience of it is bridged. In this paper, we focus on some fundamental problems in perception which have attracted the attention of researchers in both robotics and infant development. Our goal was to identify points of contact already existing between the two fields, and also important questions identified in one field that could fruitfully be addressed in the other. We start with the problem of object segregation: how do infants and robots determine visually where one object ends and another begins? For object segregation, both the fields have examined the idea of using ,key events' where perception is in some way simplified and the infant or robot acquires knowledge that can be exploited at other times. We propose that the identification of the key events themselves constitutes a point of contact between the fields. Although the specific algorithms used in robots do not necessarily map directly to infant strategies, the overall ,algorithmic skeleton' formed by the set of algorithms needed to identify and exploit key events may in fact form the basis for mutual dialogue. We then look more broadly at the role of embodiment in humans and robots, and see the opportunities it affords for development. Copyright © 2008 John Wiley & Sons, Ltd. [source] Assembly, tuning, and transfer of action systems in infants and robotsINFANT AND CHILD DEVELOPMENT, Issue 1 2008Luc Berthouze Abstract This paper seeks to foster a discussion on whether experiments with robots can inform theory in infant motor development and specifically (1) how the interactions among the parts of a system, including the nervous and musculoskeletal systems and the forces acting on the body, induce organizational changes in the whole, and (2) how exploratory behaviour and selective informational signals at the timescale of skill learning may allow behaviour to become stabilized at the longer timescale of development. The paper describes how three generative principles, inspired from developmental biology and shown to underlie the dynamics of infants learning to bounce in a Jolly Jumper, were broken into a set of mechanisms suitable for controlling a robotic system and resulted in a similar developmental profile. A comparison of infant and robot data leads to a set of criteria for improving the usefulness of robotic studies. Copyright © 2008 John Wiley & Sons, Ltd. [source] Adaptive motion/force tracking control of holonomic constrained mechanical systems: a unified viewpointINTERNATIONAL JOURNAL OF ADAPTIVE CONTROL AND SIGNAL PROCESSING, Issue 5 2007Chian-Song Chiu Abstract This paper proposes a robust adaptive motion/force tracking controller for holonomic constrained mechanical systems with parametric uncertainties and disturbances. First, two types of well-known holonomic systems are reformulated as a unified control model. Based on the unified control model, an adaptive scheme is then developed in the presence of pure parametric uncertainty. The proposed controller guarantees asymptotic motion and force tracking without the need of extra conditions. Next, when considering external disturbances, control gains are designed by solving a linear matrix inequality (LMI) problem to achieve prescribed robust performance criterion. Indeed, arbitrary disturbance/parametric error attenuation with respect to both motion and force errors along with control input penalty are ensured in the L2 -gain sense. Finally, applications are carried out on a two-link constrained robot and two planar robots transporting a common object. Numerical simulation results show the expected performances. Copyright © 2006 John Wiley & Sons, Ltd. [source] Adaptive tracking control for electrically-driven robots without overparametrizationINTERNATIONAL JOURNAL OF ADAPTIVE CONTROL AND SIGNAL PROCESSING, Issue 2 2002Yeong-Chan Chang Abstract This paper addresses the motion tracking control of robot systems actuated by brushed direct current motors in the presence of parametric uncertainties and external disturbances. By using the integrator backstepping technique, two kinds of adaptive control schemes are developed: one requires the measurements of link position, link velocity and armature current for feedback and the other requires only the measurements of link position and armature current for feedback. The developed adaptive controllers guarantee that the resulting closed-loop system is locally stable, all the states and signals are bounded, and the tracking error can be made as small as possible. The attraction region can be not only arbitrarily preassigned but also explicitly constructed. The main novelty of the developed adaptive control laws is that the number of parameter estimates is exactly equal to the number of unknown parameters throughout the entire electromechanical system. Consequently, the phenomenon of overparametrization, a significant drawback of employing the integrator backstepping technique to treat the control of electrically driven robots in the previous literature, is eliminated in this study. Finally, simulation examples are given to illustrate the tracking performance of electrically driven robot manipulators with the developed adaptive control schemes. Copyright © 2002 John Wiley & Sons, Ltd. [source] RTSVC: Real-time system for visual control of robotsINTERNATIONAL JOURNAL OF IMAGING SYSTEMS AND TECHNOLOGY, Issue 4 2008Eusebio Bugarin Abstract This article presents an image processing system that can work in hard real-time. Compared with systems that use the traditional multiprocessor architecture approach, this computer system takes advantage on recent technological advances and it is designed to work with a single processor PC under RTLinux. Its programming environment is similar to C programming language and it offers a friendly graphical user interface. The performance of the system is illustrated by means of experiments applied to visual guidance of mobile robots via velocity fields using a fixed high-speed camera. The experiments were carried out with a strict sampling frequency of 100 Hz. © 2008 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 18, 251,256, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). [source] Hybrid learning architecture for fuzzy control of quadruped walking robotsINTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS, Issue 2 2005Huosheng Hu This article presents a hybrid learning architecture for fuzzy control of quadruped walking robots in the RoboCup domain. It combines reactive behaviors with deliberative reasoning to achieve complex goals in uncertain and dynamic environments. To achieve real-time and robust control performance, fuzzy logic controllers (FLCs) are used to encode the behaviors and a two-stage learning scheme is adopted to make these FLCs be adaptive to complex situations. The first stage is called structure learning, in which the rule base of an FLC is generated by a Q-learning scheme. The second stage is called parameter learning, in which the parameters of membership functions in input fuzzy sets are learned by using a real value genetic algorithm. The experimental results are provided to show the suitability of the architecture and effectiveness of the proposed learning scheme. © 2005 Wiley Periodicals, Inc. Int J Int Syst 20: 131,152, 2005. [source] Integrating fuzzy topological maps and fuzzy geometric maps for behavior-based robotsINTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS, Issue 3 2002Eugenio Aguirre In behavior-based robots, planning is necessary to elaborate abstract plans that resolve complex navigational tasks. Usually maps of the environment are used to plan the robot motion and to resolve the navigational tasks. Two types of maps have been mainly used: metric and topological maps. Both types present advantages and weakness so that several integration approaches have been proposed in literature. However, in many approaches the integration is conducted to build a global representation model, and the planning and navigational techniques have not been fitted to profit from both kinds of information. We propose the integration of topological and metric models into a hybrid deliberative-reactive architecture through a path planning algorithm based on A* and a hierarchical map with two levels of abstraction. The hierarchical map contains the required information to take advantage of both kinds of modeling. On one hand, the topological model is based on a fuzzy perceptual model that allows the robot to classify the environment in distinguished places, and on the other hand, the metric map is built using regions of possibility with the shape of fuzzy segments, which are used later to build fuzzy grid-based maps. The approach allows the robot to decide on the use of the most appropriate model to navigate the world depending on minimum-cost and safety criteria. Experiments in simulation and in a real office-like environment are shown for validating the proposed approach integrated into the navigational architecture. © 2002 Wiley Periodicals, Inc. [source] Robust discontinuous exponential regulation of dynamic nonholonomic wheeled mobile robots with parameter uncertaintiesINTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 9 2008B. L. Ma Abstract For regulating a dynamic nonholonomic WMR (wheeled mobile robot) with parameter uncertainties, we derive a simple robust discontinuous control law, yielding a global exponential convergence of position and orientation to the desired set point despite parameter uncertainties. The controller design relies on separating the error dynamics into two subsystems, followed by robust feedback control laws to stabilize the subsystems. The effectiveness of the proposed control laws is verified by simulation. Copyright © 2007 John Wiley & Sons, Ltd. [source] Robotics in urologic surgery: An evolving new technologyINTERNATIONAL JOURNAL OF UROLOGY, Issue 7 2006FATIH ATUG Abstract, Rapid technological developments in the past two decades have produced new inventions such as robots and incorporated them into our daily lives. Today, robots perform vital functions in homes, outer space, hospitals and on military instillations. The development of robotic surgery has given hospitals and health care providers a valuable tool that is making a profound impact on highly technical surgical procedures. The field of urology is one area of medicine that has adopted and incorporated robotic surgery into its armamentarium. Innovative robotic urologic surgical applications and techniques are being developed and reported everyday. Increased utilization and development will ultimately fuel the discovery of newer applications of robotic systems in urologic surgery. Herein we provide an overview of the history, development, and applications of robotics in surgery with a focus on urologic surgery. [source] Automated seeding for the optimization of crystal qualityJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 4 2010Sahir Khurshid With the advent of structural genomics a variety of crystallization techniques have been automated and applied to high-throughput pipelines, yet seeding, which is the most common and successful optimization method, is still being performed predominantly manually. The aim of this study was to devise simple automated seeding techniques that can be applied in a routine manner using existing robots and not requiring special tools. Two alternative protocols for automated seeding experiments are described. One involves the delivery of microcrystals from stock to target wells using the robot dispensing tip as a seeding tool. The second harnesses an animal whisker as the seeding tool. Larger and better ordered crystals were obtained using both techniques. [source] | |||||||||||||||||||||||||||||||||||||