关键词： MANIPULATORS (Machinery)   ELECTRIC potential   ROBOTS -- Control systems   DYNAMICS   SIGNAL processing   ALGORITHMS  

摘要： A class of voltage-driven robot manipulators is addressed in this paper. Such a class includes those manipulators actuated by direct current (DC) motors with servo-amplifiers in current mode. For those robots, it is assumed that the control inputs to the manipulator are the servo-amplifier input voltages, instead of the applied torques. And even though it is common to consider that the applied torque in each joint is proportional to the servo-amplifier input voltage, in this paper it is assumed that the voltage-to-torque conversion constant is unknown. Notwithstanding, the robot model parameters may still be computed using standard identification methods. An important fact of the class of robots considered in the present study is that the robot dynamics is not passive from the servo-amplifier input voltage to the joint velocity. The paper shows how this drawback can be overcome by using a model-based trajectory tracking controller, which makes the closed-loop system passive from an auxiliary control input to a filtered error signal. To confirm the theoretical conclusions, real-time experiments are carried out in a two-degree-of-freedom direct-drive manipulator. Two known control strategies are compared with respect to the proposed controller. The success of the implementations is based on real-time computing, which ensures that the access to I/O ports and the computation of the control algorithms meet timing requirements accurately. (C) 2013 Elsevier Ltd. All rights reserved.

关键词： Range sensing   Comparative evaluation   Automated logistics  

摘要： 3D range sensing is an important topic in robotics, as it is a component in vital autonomous subsystems such as for collision avoidance, mapping and perception. The development of affordable, high frame rate and precise 3D range sensors is thus of considerable interest. Recent advances in sensing technology have produced several novel sensors that attempt to meet these requirements. This work is concerned with the development of a holistic method for accuracy evaluation of the measurements produced by such devices. A method for comparison of range sensor output to a set of reference distance measurements, without using a precise ground truth environment model, is proposed. This article presents an extensive evaluation of three novel depth sensors the Swiss Ranger SR-4000, Fotonic B70 and Microsoft Kinect. Tests are concentrated on the automated logistics scenario of container unloading. Six different setups of box-, cylinder-, and sack-shaped goods inside a mock-up container are used to collect range measurements. Comparisons are performed against hand-crafted ground truth data, as well as against a reference actuated Laser Range Finder (aLRF) system. Additional test cases in an uncontrolled indoor environment are performed in order to evaluate the sensors' performance in a challenging, realistic application scenario. (C) 2012 Elsevier B.V. All rights reserved.

关键词： RISCWare   Middleware   Plug and play   Teleoperation   Face detection   Face recognition   Modular design   Architecture   RISCbot II  

摘要： In this paper, the RISCWare framework is proposed as a robotic middleware for the modular design of sensory modules, actuation platforms, and task descriptions. This framework will be used to customize robotic platforms by simply defining the available sensing devices, actuation platforms and required tasks. In addition, this framework will significantly increase the capability of robotic industries in the analysis, design, and development of autonomous mobile platforms. RISCWare is comprised of three modules. The first module encapsulates the sensors, which gather information about the remote or local environment. The second module defines the platforms, manipulators, and actuation methods. The last module describes the tasks that the robotic platforms will perform such as teleoperation, navigation, obstacle avoidance, manipulation, 3-D reconstruction, and map building. The objective is to design a middleware framework to allow a user to plug in new sensors, tasks or actuation hardware, resulting in a fully functional operational system. Furthermore, the user is able to install and uninstall hardware/software components through system lifetime with ease and modularity. In addition, when hardware devices are plugged into the framework, they are automatically detected by the middleware layer, which loads the appropriate software and avails the device for applications usage. This automatic detection and configuration of devices make it efficient and seamless for end users to add and use new devices and software applications. Several experiments, performed on the RISCbot II mobile robot, are implemented to evaluate the RISCWare framework with respect to applicability and resource utilization.

关键词： WAR horses   HORSES  

摘要： Through examining the shift from the literary representation of the horse, to its depiction by puppets, to the cinematic "real" bodies onscreen in the production development of the film War Horse, this essay suggests that performance offers an imaginative space that can enable us to reconceptualize the interspecies relationships between the human and the nonhuman. It examines these performance spaces alongside technological developments that have revolved around the bodies of animals, interweaving the move in military developments from the live horse, to the tank, to the animal-shaped drone/robot. Tracing an interspecies reliance between humans and animals that has its roots in mechanical representations of animals, such as automata and the early cinematic exploration of animal bodies, the essay raises questions about the possibilities of performance to foster more collaborative interchanges between human and nonhuman animals. The reliance upon animal bodies in historical and current military development, such as DARPA's hummingbird drone and Cheetah robot, have allowed technologized "animals" to replace humans in extreme situations, while engagement with the animal through the puppet form, despite its absence, reminds us of its presence.

关键词： Surgeons   digital domain   Comment   Urologic Surgical Procedures   nephron sparing surgery   robotics   letter  

摘要： We read with great interest the letter from Borghesi et al.8 referring to our article released in this issue of the European Journal of Surgical Oncology (Eur J Surg Oncol (2013), http://***/10.1016/***.2013.03.007). We definitely agree with the vision of the future of robotics delivered by our colleagues in their comment. We are also convinced that the next step of the development of robotic is going to be mainly in the field of upper urinary tract surgery. This is why there is an urgent need of prospective data in the area of robotics nephron sparing surgery not only mentioning the oncological outcomes but also the 'dark side' of the procedure (i.e., complications and morbidity of the technique) as a surrogate of quality and objective evaluation.

关键词： ROBOTICS   PROSTHESIS -- Design & construction   WHEELCHAIRS  

摘要： The article focuses on the use of robotic technologies in prosthetics to help injured warfighters in leading a normal life. Doctor Robert Jaeger explains that the U.S. Department of Veterans Affairs (VA), U.S. Department of Defense (DOD), and National Institutes of Health (NIH) are looking for possible breakthrough on computer-interpreted brain waves that can control prosthetic movement. Severa cutting-edge prosthetic technologies are mentioned including powered ankle and DEKA iBot wheelchair.

关键词： EXPERIMENTS   ROBOTS   MECHANICAL movements   ENERGY development   COMPARISON (Rhetoric)   ATTENTION  

摘要： In this paper we investigate whether selective attention enables the development of action selection (i.e. the ability to select among conflicting actions afforded by the current agent/environmental context). By carrying out a series of experiments in which neuro-robots have been evolved for the ability to forage so to maximize the energy that can be extracted from ingested substances we observed that effective action and action selection capacities can be developed even in the absence of internal mechanisms specialized for action selection. However, the comparison of the results obtained in different experimental conditions in which the robots were or were not provided with internal modulatory connections demonstrate how selective attention enables the development of a more effective action selection capacity and of more effective and integrated action capacities.

关键词： Centroidal momentum matrix   Angular momentum   Robot dynamics algorithms   Average spatial velocity   Humanoid balance controller   Momentum based balance control  

摘要： The center of mass (CoM) of a humanoid robot occupies a special place in its dynamics. As the location of its effective total mass, and consequently, the point of resultant action of gravity, the CoM is also the point where the robot's aggregate linear momentum and angular momentum are naturally defined. The overarching purpose of this paper is to refocus our attention to centroidal dynamics: the dynamics of a humanoid robot projected at its CoM. In this paper we specifically study the properties, structure and computation schemes for the centroidal momentum matrix (CMM), which projects the generalized velocities of a humanoid robot to its spatial centroidal momentum. Through a transformation diagram we graphically show the relationship between this matrix and the well-known joint-space inertia matrix. We also introduce the new concept of "average spatial velocity" of the humanoid that encompasses both linear and angular components and results in a novel decomposition of the kinetic energy. Further, we develop a very efficient algorithm, expressed in a compact form using spatial notation, for computing the CMM, centroidal momentum, centroidal inertia, and average spatial velocity. Finally, as a practical use of centroidal dynamics we show that a momentum-based balance controller that directly employs the CMM can significantly reduce unnecessary trunk bending during balance maintenance against external disturbance.

关键词： Stroke   Aerobic exercise   Sub-acute   Non-ambulatory   Aerobic capacity   Robotics-assisted  

摘要： Background: After experiencing a stroke, most individuals also suffer from cardiac disease, are immobile and thus have low endurance for exercise. Aerobic capacity is seriously reduced in these individuals and does not reach reasonable levels after conventional rehabilitation programmes. Cardiovascular exercise is beneficial for improvement of aerobic capacity in mild to moderate stroke. However, less is known about its impact on aerobic capacity, motor recovery, and quality-of-life in severely impaired individuals. The aim of this pilot study is to explore the clinical efficacy and feasibility of cardiovascular exercise with regard to aerobic capacity, motor recovery, and quality-of-life using feedback-controlled robotics-assisted treadmill exercise in non-ambulatory individuals soon after experiencing a stroke. Methods/Design: This will be a single-centred single blind, randomised control trial with a pre-post intervention design. Subjects will be recruited early after their first stroke (<= 20 weeks) at a neurological rehabilitation clinic and will be randomly allocated to an inpatient cardiovascular exercise programme that uses feedback-controlled robotics-assisted treadmill exercise (experimental) or to conventional robotics-assisted treadmill exercise (control). Intervention duration depends on the duration of each subject's inpatient rehabilitation period. Aerobic capacity, as the primary outcome measure, will be assessed using feedback-controlled robotics-assisted treadmill-based cardiopulmonary exercise testing. Secondary outcome measures will include gait speed, walking endurance, standing function, and quality-of-life. Outcome assessment will be conducted at baseline, after each 4-week intervention period, and before clinical discharge. Ethical approval has been obtained. Discussion: Whether cardiovascular exercise in non-ambulatory individuals early after stroke has an impact on aerobic capacity, motor recovery, and quality-of-life is not yet known. Feed

关键词： Robotic agent   Mechatronics   Mobile robot kinematics   Mobile robot motion-planning   Cooperative systems  

摘要： This paper presents the development of the robotic multi-agent system SMART. In this system, the agent concept is applied to both hardware and software entities. Hardware agents are robots, with three and four legs, and an IP-camera that takes images of the scene where the cooperative task is carried out. Hardware agents strongly cooperate with software agents. These latter agents can be classified into image processing, communications, task management and decision making, planning and trajectory generation agents. To model, control and evaluate the performance of cooperative tasks among agents, a kind of Petri Net, called Work-Flow Petri Net, is used. Experimental results shows the good performance of the system. (C) 2013 Elsevier Ltd. All rights reserved.