waashk/dblp huggingface dataset:
planning the reconfiguration of grounded truss structures with truss climbing robots that carry truss elements. in this paper we describe an optimal reconfiguration planning algorithm that morphs a grounded truss structure of known geometry into a new geometry. the plan consists of a sequence of paths to move truss elements to their new locations that generate the new truss geometry. the trusses are grounded and remain connected at all time. intuitively, the algorithm grows gradually the new truss structure from the old one. the truss elements are rigid bars joined with 18-way connectors. the paper also introduces the design of a truss-climbing robot that can execute the plan.
self-adapting modular robotics: a generalized distributed consensus framework. biological systems achieve amazing adaptive behavior with local agents performing simple sensing and actions. modular robots with similar properties can potentially achieve self-adaptation tasks robustly. inspired by this principle, we present a generalized distributed consensus framework for self-adaptation tasks in modular robotics. we demonstrate that a variety of modular robotic systems and tasks can be formulated within such a framework, including (1) an adaptive column that can adapt to external force, (2) a modular gripper that can manipulate fragile objects, and (3) a modular tetrahedral robot that can locomote towards a light source. we also show that control algorithms derived from this framework are provably correct. in real robot experiments, we demonstrate that such a control scheme is robust towards real world sensing and actuation noise. this framework can potentially be applied to a wide range of distributed robotics applications.
multi-jointed robot finger driven by artificial muscle actuator. in this paper we present a robotic actuation system by artificial muscle actuator based on dielectric elastomer. a novel linear actuator called "multi-stacked actuator" is presented, which can be embedded in the phalanges of the finger and ensures a compact design of the overall system. as an exemplary work, a two degree-of-freedom robot finger is developed and its performance is experimentally demonstrated. the proposed system can be extended to the multifingered robot hand easily, and applied even for articulated mechanisms such as legged robots etc.
development of the airway management training system wka-2 designed to reproduce different cases of difficult airway. the emerging field of medical robotics aims to introduce intelligent tools to assist a physician. the main challenges for developing efficient medical robotic training systems are simulating real-world conditions of the task and assuring training effectiveness. high anatomic fidelity has been achieved in current systems. however, those training systems are designed to reproduce specific conditions of the task (passive training). in this research, we are focusing in developing an airway management training systems designed to reproduce various cases of difficult airway. such difficulties (i.e. restricted mouth opening, various shapes of oral cavity including tongue swallowing, etc) may provoke traumas on different organs of the patient during an emergency situation. for this purpose, the authors have proposed the development of more advanced training tools. for this purpose, we have focused in embedding sensors and actuators to a conventional patient model towards the development of a patient robot (in previous research, authors have presented the evaluation model which embeds sensors). in this paper, we present an airway training system which embeds actuators into a mannequin. in particular, the mechanism design of the waseda kyotokagaku airway no.2 (wka-2) is detailed. the wka-2 is composed of twelve active and one passive degrees of freedom; which are designed to reproduce the various cases of difficult airway. for this purpose, the wka-2 reproduces the human muscles around the upper airway based on a wire driving mechanisms (a total of sixteen wires are used). in particular, the head of the model is composed of a tongue and mandible with translational and rotational movements around kinematic axis. in addition, we present the details of the kinematic model of wka-2 which enable the robot to reproduce the airway difficulties. finally, we presented the design of a tension sensor designed to measure the applied tension on each of the wire driving mechanism of wka-2. as preliminary experiments, we reproduce several cases of difficult airways using wka-2.
automatically and efficiently inferring the hierarchical structure of visual maps. in simultaneous localisation and mapping (slam), it is well known that probabilistic filtering approaches which aim to estimate the robot and map state sequentially suffer from poor computational scaling to large map sizes. various authors have demonstrated that this problem can be mitigated by approximations which treat estimates of features in different parts of a map as conditionally independent, allowing them to be processed separately. when it comes to the choice of how to divide a large map into such 'submaps', straightforward heuristics may be sufficient in maps built using sensors such as laser range-finders with limited range, where a regular grid of submap boundaries performs well. with visual sensing, however, the ideal division of submaps is less clear, since a camera has potentially unlimited range and will often observe spatially distant parts of a scene simultaneously. in this paper we present an efficient and generic method for automatically determining a suitable submap division for slam maps, and apply this to visual maps built with a single agile camera. we use the mutual information between predicted measurements of features as an absolute measure of correlation, and cluster highly correlated features into groups. via tree factorisation, we are able to determine not just a single level submap division but a powerful fully hierarchical correlation and clustering structure. our analysis and experiments reveal particularly interesting structure in visual maps and give pointers to more efficient approximate visual slam algorithms.
a four degree of freedom microrobot with large work volume. this paper presents a unique four-axis articulated mems robot, constructed by microassembly, targeting micro and nano scale manipulation and probing applications. the first version of this microrobot has a 2p2r (prismatic prismatic revolute revolute) kinematic configuration, occupies a total volume of 3mm × 2mm × 1mm, and operates within a workspace envelope of 50µm × 50µm × 75µm. this is by far the largest operating envelope of any independent micropositioner with non-planar dexterity. as a result, it can be classified as a new type of 3 dimensional miniaturized top-down assembly robot with dimensions smaller than 1 cm. the robot incorporates a combination of miniature flexures and cables to drive its joints from high force mems actuators. actuation is accomplished via two banks of in-plane electrothermal actuators, one coupled through an out of plane compliant socket, and the other one coupled remotely via a 30 µm diameter cu wire. in this paper, we decouple the motion of the robot joints by identifying the robot jacobian, and we offer preliminary experimental characterization of the microrobot repeatability. results show that the robot is repeatable to under 0.5 µm along xy and 0.015 degrees along pitch and yaw degrees of freedom.
the latency model for viscoelastic contact interface in robotics: theory and experiments. viscoelasticity is the phenomenon of time-dependent strain and/or stress in elastic solids. various contact interfaces with anthropomorphic end-effectors and polymeric solids found in robots and manipulators are intrinsically viscoelastic. it is therefore important to model such behavior and to study the effects of such time-dependent strain and stress on the stability and sustainability of grasping and manipulation. various models have been proposed over the years to describe such behavior of time-dependent strain and stress. furthermore, viscoelastic solids also display typically nonlinear elastic response. built upon a variety of literature, a new and practical latency model is proposed in this paper for the application of contact interface involving viscoelasticity in robotics. latency model can describe various features of viscoelastic materials, such as stress relaxation, creep, and material clock. the theoretical modeling was supported by experiments in which we found two types of relaxation, depending on the loading and unloading of grasping or contact. one type is well documented in existing literature; but the other type has not been, to our best knowledge, presented before. the proposed theory can unify both types of time-dependent relaxation responses.
an interactive tool for designing complex robot motion patterns. low-cost robots with a large number of degrees of freedom are becoming increasingly popular, nevertheless their programming is still a domain for experts. this paper introduces the kouretes motion editor (kme), a freely-available interactive software tool for designing complex motion patterns on robots with many degrees of freedom using intuitive means. kme allows for a tcp/ip connection to a real or simulated robot, over which various robot poses can be communicated to or from the robot and manipulated locally using the kme graphical user interface. this portability and flexibility enables the user to work under different modes, with different robots, using different host machines. kme is originally designed for the aldebaran nao humanoid robot which features a total of 21 degrees of freedom, but can be easily customized for other robots. kme has been employed successfully by kouretes, the robocup team of the technical university of crete, for designing various special actions at the robocup 2008 competition (standard platform league).
high-accuracy 3d sensing for mobile manipulation: improving object detection and door opening. high-resolution 3d scanning can improve the performance of object detection and door opening, two tasks critical to the operation of mobile manipulators in cluttered homes and workplaces. we discuss how high-resolution depth information can be combined with visual imagery to improve the performance of object detection beyond what is (currently) achievable with 2d images alone, and we present door-opening and inventory-taking experiments.
development of the anthropomorphic saxophonist robot was-1: mechanical design of the lip, tonguing, fingers and air pump mechanisms. the research on the development of musical performance robots has been particularly intensified on the last decades. in fact, the development of anthropomorphic robots able of playing musical instruments have been served as a mean for understanding the human motor control from an engineering point of view as well as understanding how to enable the communication between human and robots from an emotional point of view. in particular, our research aims in the development of an anthropomorphic saxophonist robot which is able not only of performing a musical score; but also to interact with other musical performance robots (i.e. waseda flutist robot) at the emotional level of perception. in this year, we have focused on the mechanical design of an anthropomorphic robot waseda saxophonist robot no. 1 (was-1); which has been designed for playing an alto saxophone. was-1 has a total of 15-dofs which mechanically reproduces the following organs involved during the saxophone playing: lips (1-dof), tongue (1-dof), oral cavity, lungs (air pump: 1-dof and air valve: 1-dof) and fingers (11-dofs). in order to verify the effectiveness of the production of sound, a set of experiments have been proposed. in particular, the characteristics of air flow-pressure, level of mechanical noise, and the ripple effect ratio are presented. finally, a qualitative evaluation of the sound produced by was-1 is presented and discussed. from the experimental results, we have confirmed the effectiveness of the proposed mechanisms to produce the saxophone sound.
smooth path planning in constrained environments. in this paper we describe a novel path planning approach for mobile robots operating in indoor environments. in such scenarios, robots must be able to maneuver in crowded spaces, partially filled with static and dynamic obstacles (such as people). our approach produces smooth, complex maneuvers over large distances through the use of an anytime graph search algorithm applied to a novel multi-resolution state lattice, where the resolution is adapted based on both environmental characteristics and task characteristics. in addition, we present a novel approach for generating fast globally optimal trajectories in constrained spaces (i.e. rooms connected via doors and hallways). this approach exploits offline precomputation to provide extremely efficient online performance and is applicable to a wide range of both indoor and outdoor navigation scenarios. by combining an anytime, multi-resolution lattice-based search algorithm with our precomputation technique, globally optimal trajectories in up to four dimensions (2d position, heading and velocity) are obtained in real-time.
modeling and 3d local estimation for in-plane and out-of-plane motion guidance by 2d ultrasound-based visual servoing. this paper presents a new model-free visual servoing that is able to servo a robotized 2d ultrasound probe that interacts with a soft tissue object. it makes direct use of the b-mode ultrasound images in order to reach a desired one. this approach does not require the 3d model of the object nor its location in the 3d space. the visual features are based on image moments. the exact analytical form of the interaction matrix relating the image moments variation to the probe velocity is modelled. to perform model-free servoing, the approach combines the image points coordinates with the probe pose to estimate efficiently 3d parameters required in the control law. the approach is validated with simulation and experimental results showing its robustness to different errors and perturbations.
robust 3d slam with a stereo camera based on an edge-point icp algorithm. most vision-based slam systems utilize corner-like features, and may be unstable in non-textured environments where only a few corner features can be extracted. to cope with this problem, we employ edge points to perform slam with a stereo camera. the edge-point based slam is applicable to non-textured environments since plenty of edge points can be obtained even from a small number of lines. the proposed method estimates camera poses and builds detailed 3d maps robustly by aligning edge points between frames using the icp algorithm. in indoor experiments, the method successfully built detailed 3d maps even under noisy condition.
design considerations and human-machine performance of moving virtual fixtures. haptic virtual fixtures have been shown to improve user performance and increase the safety of robot-assisted tasks, particularly for surgical applications. however, little research has studied virtual fixtures that provide moving force constraints based on motion of the environment, e.g., organ movement due to heartbeat or respiration. this work discusses design considerations of moving forbidden-region virtual fixtures and presents two methods of implementation: predicted-position and current-position virtual fixtures. human subject experiments were performed to determine the effectiveness of moving virtual fixtures when interacting with an object in motion using a teleoperator. results show that moving virtual fixtures can help improve user precision and decrease the amount of force applied.
design and simulation of a joint-coupled orthosis for regulating fes-aided gait. a hybrid functional electrical stimulation (fes)/orthosis system is being developed which combines two channels of (surface-electrode-based) electrical stimulation with a computer-controlled orthosis for the purpose of restoring gait to spinal cord injured (sci) individuals (albeit with a stability aid, such as a walker). the orthosis is an energetically passive, controllable device which 1) unidirectionally couples hip to knee flexion; 2) aids hip and knee flexion with a spring assist; and 3) incorporates sensors and modulated friction brakes, which are used in conjunction with electrical stimulation for the feedback control of joint (and therefore limb) trajectories. this paper describes the hybrid fes approach and the design of the joint coupled orthosis. a dynamic simulation of an sci individual using the hybrid approach is described, and results from the simulation are presented that indicate the promise of the jco approach.
the autonomous city explorer project. this video presents the autonomous city explorer (ace) project. its goal was to create a robot capable of navigating unknown urban environments without the use of gps data or prior map knowledge. the robot had to find its way solely by interacting with pedestrians and building a topological representation of its surroundings. this video outlines the necessary ingredients for successful low-level navigation on sidewalks, information retrieval from pedestrians as well as the construction of a semantic representation of an urban environment. a system architecture for outdoor localization, traversability assessment, path planning, behavior selection and topological abstraction in urban environments is presented.
fluorescent monitoring using microfluidics chip and development of syringe pump for automation of enucleation to automate cloning. we have developed a novel technique for fluorescent monitoring of a bovine oocyte nucleus for an automatic cloning device. animal cells that have been chemically softened by cytochalasin and stained with hoechst dye are aspirated into a thin microchannel of a microfluidic chip and stretched thin, allowing the nucleus of the expanded oocyte to be monitored. half the volume of the oocyte is aspirated into the thin microchannel and a high-velocity fluid flow is generated in the wide microchannel to bisect the oocyte. then, the half-oocytes are monitored to determine which contains the nucleus. to control flow velocity with high accuracy and rapid response, we also developed a syringe pump that is small, has no backlash, and has highly-accurate volume control and a good response for automatic cutting. in this report, we describe the monitoring method and construction of the syringe pump.
the "dlr crash report": towards a standard crash-testing protocol for robot safety - part i: results. after analyzing fundamental impact characteristics of robot-human collisions in our previous work, the intention in the present paper is to augment existing knowledge in this field, verify previously given statements with standardized equipment of the german automobile club (adac), and provide a crash-test report for robots in general. various new insights are achieved and a systematic and extensive set of data is provided. the presented work is divided into two papers. the main purpose of part i is to give, similarly to reports known from the automobile world1, a fact based and result oriented view on our newest robot crash-test experiments. in part ii detailed discussions of the results listed in the present paper and recommendations towards a standard crash-test protocol for robot safety are carried out.
2 dof cartesian force limiting device for safe physical human-robot interaction. this paper presents a device that significantly increases the safety level of suspended robots whose end-effector orientation remains constant with respect to the vertical direction (e.g. scara-type suspended robots). the device is a two-degree-of-freedom (dof) parallel mechanism with a parallepipedic architecture on which two revolute joints have been replaced with commercially available torque limiters. the device is implemented as a mechanical connection between the robot and the effector. it is rigid unless excessive horizontal forces are applied on the end-effector, for example during a collision. the level of force that activates the mechanism is set by properly adjusting the threshold of the torque limiters. furthermore, a collision can be rapidly detected with a limit switch placed on one of the links of the mechanism and a signal can be sent directly to brakes that will stop the robot, without passing through a controller and thus improving the reliability and reaction-time of the safety system. by mechanically disconnecting the robot from its end-effector, the device ensures that the person involved in the collision is only subjected to the inertia of the end-effector and thus potential injuries are greatly reduced. a prototype of the proposed device has been built to validate the concept and to study its behaviour for collisions with different velocities and orientations.
expansion segmentation for visual collision detection and estimation. collision detection and estimation from a monocular visual sensor is an important enabling technology for safe navigation of small or micro air vehicles in near earth flight. in this paper, we introduce a new approach called expansion segmentation, which simultaneously detects "collision danger regions" of significant positive divergence in inertial aided video, and estimates maximum likelihood time to collision (ttc) in a correspondenceless framework within the danger regions. this approach was motivated from a literature review which showed that existing approaches make strong assumptions about scene structure or camera motion, or pose collision detection without determining obstacle boundaries, both of which limit the operational envelope of a deployable system. expansion segmentation is based on a new formulation of 6- dof inertial aided ttc estimation, and a new derivation of a first order ttc uncertainty model due to subpixel quantization error and epipolar geometry uncertainty. proof of concept results are shown in a custom designed urban flight simulator and on operational flight data from a small air vehicle.
continuous 3d scan-matching with a spinning 2d laser. scan-matching is a technique that can be used for building accurate maps and estimating vehicle motion by comparing a sequence of point cloud measurements of the environment taken from a moving sensor. one challenge that arises in mapping applications where the sensor motion is fast relative to the measurement time is that scans become locally distorted and difficult to align. this problem is common when using 3d laser range sensors, which typically require more scanning time than their 2d counterparts. existing 3d mapping solutions either eliminate sensor motion by taking a "stop-and-scan" approach, or attempt to correct the motion in an open-loop fashion using odometric or inertial sensors. we propose a solution to 3d scan-matching in which a continuous 6dof sensor trajectory is recovered to correct the point cloud alignments, producing locally accurate maps and allowing for a reliable estimate of the vehicle motion. our method is applied to data collected from a 3d spinning lidar sensor mounted on a skid-steer loader vehicle to produce quality maps of outdoor scenes and estimates of the vehicle trajectory during the mapping sequences.
reactive grasping using optical proximity sensors. we propose a system for improving grasping using fingertip optical proximity sensors that allows us to perform online grasp adjustments to an initial grasp point without requiring premature object contact or regrasping strategies. we present novel optical proximity sensors that fit inside the fingertips of a barrett hand, and demonstrate their use alongside a probabilistic model for robustly combining sensor readings and a hierarchical reactive controller for improving grasps online. this system can be used to complement existing grasp planning algorithms, or be used in more interactive settings where a human indicates the location of objects. finally, we perform a series of experiments using a barrett hand equipped with our sensors to grasp a variety of common objects with mixed geometries and surface textures.