waashk/dblp huggingface dataset:
tracking intraocular microdevices based on colorspace evaluation and statistical color/shape information. successful ophthalmic surgeries using intraocular untethered microrobots or tethered robotic microtools require methods to robustly track the microdevices in the posterior of the human eye. the dimensions and specularities of the microdevices are major obstacles for accurate tracking. in addition, the optical structure of the human eye makes it challenging to keep the objects of interest constantly in focus, resulting in blurred images. in this paper, the advantages of using different colorspacaes for intraocular tracking are examined. after selection of the appropriate colorspace, thresholds that ensure maximum separation of the device from the background are calculated. based on trained color histograms, level sets are used to track in real time, and the use of statistical shape information is incorporated in the existing tracking framework. the efficacy of the algorithm is demonstrated by tracking a microrobot in a model eye, using a custom made ophthalmoscope and off-the-shelf opthalmoscopy lenses. with the appropriate colorspace and threshold selection, tracking errors are minimized and are further diminished using shape information.
object handling tasks based on active tactile and slippage sensations in a multi-fingered humanoid robot arm. this paper presents a new algorithm for object handling tasks based on active tactile and slippage sensations using a humanoid robot multi-fingered arm for an object that exists at an arbitrary position. the idea is to enhance real-time object handling tasks based on tactile sensing in humanoid robotics, where grasp, move and release motions are involved. we developed a novel hemisphere-shaped optical three-axis tactile sensor to mount on fingertips of the robot arm. the tactile sensor is capable of defining normal and shearing forces simultaneously. for grasp and release motions, we designed the algorithm based on slippage direction analysis consisting of coordinate transformation of the sensing element for the arm global coordinate. the robot control system uses the analysis results to determine whether an object is in contact with the ground without needing to measure the height of the ground. the algorithm was evaluated in experiments with soft and hard objects, whereby results revealed good performance for the robot fingers in handling an object at an arbitrary position.
affordance based word-to-meaning association. this paper presents a method to associate meanings to words in manipulation tasks. we base our model on an affordance network, i.e., a mapping between robot actions, robot perceptions and the perceived effects of these actions upon objects. we extend the affordance model to incorporate words. using verbal descriptions of a task, the model uses temporal co-occurrence to create links between speech utterances and the involved objects, actions and effects. we show that the robot is able form useful word-to-meaning associations, even without considering grammatical structure in the learning process and in the presence of recognition errors. these word-to-meaning associations are embedded in the robot's own understanding of its actions. thus they can be directly used to instruct the robot to perform tasks and also allow to incorporate context in the speech recognition task.
modeling deformable shell-like objects grasped by a robot hand. this paper models (large) deformations of shell-like objects under the grasping of a robot hand. classical nonlinear theory of thin shells [21, pp. 186-194] is generalized to shells with arbitrary parametric middle surfaces, using a method introduced in our earlier work [13]. an experimental study demonstrates higher modeling accuracy using the nonlinear elasticity theory than its linear counterpart. given that many deformable objects undergo sizable shape changes when they are grasped, our result supports the application of nonlinear elasticity theory in the future design of grasp strategies for this type of objects.
development of high-sensitivity slip sensor using special characteristics of pressure conductive rubber. even with the eyes closed, humans are able to grip an object with minimal force without such information as the coefficient of friction or the weight. tactile sensors capable of detecting slippage are necessary for this gripping action to be realized in a robot hand. heretofore, many slip sensors were developed and produced, but there was not a slip sensor of simple structure practical for installation on fingertips of a robot hand. therefore, we propose a low-profile/lightweight slip sensor of simple structure. the special properties of pressure conductive rubber are utilized as a detection device in this sensor. in this paper, we discuss the results of trial manufacture and of slip detection property testing of this sensor. moreover, we will report the results of slip prevention experiments by this prototype slip sensor, and indicate that the pressure conductive rubber is promising as a material of slip sensor.
theoretical analysis of three bio-inspired plume tracking algorithms. we derive the theoretical performance of three bio-inspired odor source localization algorithms (casting, surgespiral and surge-cast) in laminar wind flow. based on the geometry of the trajectories and the wind direction sensor error, we calculate the distribution of the distance overhead and the mean success rate using bayes inference. our approach is related to particle filtering and produces smooth output distributions. the results are compared to existing real-robot and simulation results, and a good match is observed.
dynamic region following formation control for a swarm of robots. this paper presents a dynamic region following formation control method for a swarm of robots. in this control strategy, a swarm of robots shall move together as a group inside a dynamic region that can rotate or scale to enable the robots to adjust the formation. various desired shapes can be formed by choosing appropriate functions. unlike existing formation control methods, the proposed method do not need to have specific identities or orders in the group but yet dynamic formation can be formed for a large group of robots. this enables a swarm of robots to adjust the formation during the course of maneuver. the system is also scalable in the sense that any robot can move into the formation or leave the formation without affecting the other robots. lyapunov-like function is presented for convergence analysis of the multi-robot systems. simulation results are presented to illustrate the performance of the proposed controller.
high-speed position tracking for nanohandling inside scanning electron microscopes. this paper describes a new position tracking system that uses the scanning electron microscope as a fast, high-resolution sensor system. the position tracking system works similar to an optical encoder using a specially structured pattern as scale. thus, with low computational overhead, an accuracy below 10nm is achieved in a tungsten cathode-based microscope. the tracking system is virtually immune to changes in contrast, brightness, magnification and, to a certain extend, to defocusing. with a customized, external scan generator and scanning algorithm, the bottleneck of image acquisition can be bypassed and the position tracking system can reach update rates of more than 1 khz. furthermore, measurements can be conducted over long working ranges of up to 200 µm without losing precision.
new interval-based approach to determine the guaranteed singularity-free workspace of parallel robots. in the present paper we introduce an improved method to obtain the guaranteed singularity-free workspace of planar parallel kinematic machines. a geometric condition for the existence of singularities is extended to be used in interval analysis. therefore, we eliminate the need of calculating the inconvenient interval form of the jacobian's determinant. hence, an appropriate description of the singularity-free workspace is obtained and the computational effort is reduced significantly. with the interval-based approach error sources, like manufacturing tolerances, can be considered. consequently, regions that do not satisfy the proposed condition can be guaranteed not to have any type-two singularities. several analysis examples demonstrate the efficiency of the proposed geometrical-based solver in comparison to existing solvers, i.e. based on the jacobian's determinant.
fast needle insertion to minimize tissue deformation and damage. during needle-based procedures, transitions between tissue layers often involve puncture events that produce substantial deformation and tend to drive the needle off course. in this paper, we analyze the mechanics of these rupture events corresponding to unstable crack propagation during the insertion of a sharp needle in an inhomogeneous tissue. the force-deflection curve of the needle prior to a rupture event is modeled by a nonlinear viscoelastic kelvin model and a stress analysis is used to predict the relationship between rupture force and needle velocity. the model predicts that the force-deflection response of the needle is steeper and the tissue absorbs less energy when the needle moves faster. the force of rupture also decreases for faster insertion under certain conditions. the observed properties are sufficient to show that maximizing needle velocity minimizes tissue deformation and damage, and consequently, results in less needle insertion position error. the model predicts that tissue deformation and absorbed energy asymptotically approach lower bounds as velocity increases. experiments with porcine cardiac tissue confirm the analytical predictions.
efficient c-space and cost function updates in 3d for unmanned aerial vehicles. when operating in partially-known environments, autonomous vehicles must constantly update their maps and plans based on new sensor information. much focus has been placed on developing efficient incremental planning algorithms that are able to efficiently replan when the map and associated cost function changes. however, much less attention has been placed on efficiently updating the cost function used by these planners, which can represent a significant portion of the time spent replanning. in this paper, we present the limited incremental distance transform algorithm, which can be used to efficiently update the cost function used for planning when changes in the environment are observed. using this algorithm it is possible to plan paths in a completely incremental way starting from a list of changed obstacle classifications. we present results comparing the algorithm to the euclidean distance transform and a mask-based incremental distance transform algorithm. computation time is reduced by an order of magnitude for a uav application. we also provide example results from an autonomous micro aerial vehicle with on-board sensing and computing.
posture control of a dual-crawler-driven robot. this paper deals with a tracked robot that consists of the proposed crawler module, in which a planetary gear reducer is used as the power transmission device to give two different outputs with just one actuator. this underactuated system could perform posture control through the interaction between the front and rear modules. on occasion, the posture that the front module is lifted up can make the robot overcome obstacles actively and easily. to find out the controllable postures, the static analysis of the robot has been conducted. in this paper, we provide the control strategy for performing the posture control, and propose the control methods including direct, indirect, and cooperative control to conduct the posture control. experimental tests show the effectiveness of the control methods.
ability to hold grasped objects by underactuated hands: performance prediction and experiments. to evaluate and optimize the mechanical design of underactuated hands, a benchmark test is defined that quantifies the ability to hold grasped objects subject to force disturbances as occurs during for instance pick and place operations. the ability to hold is quantified by the magnitude of the maximum permitted static force on the center of a cylindrical object of known radius at which it can still be hold within the underactuated hand. a static grasp model is developed to efficiently calculate the effect of design parameters of the hand on this maximum force. this model is applied to a planar, underactuated hand with six degrees of freedom, calculating the maximum force while the rotational joint stiffnesses and distance between the fingers was varied. we demonstrated that the rotational joint stiffness has no effect on this force, while decreasing the distance between the fingers has a negative effect. these results were validated by measurements in an experimental setup. these preliminary results show that the developed benchmark test can be effective to evaluate and optimize the performance of underactuated hands to hold objects in pick and place operations.
torsional kinematic model for concentric tube robots. a recent approach to steerable needle design is based on combining pre-curved tubes concentrically. by rotating and extending the tubes with respect to each other, the position and orientation of the needle tip, as well as the shape of the inserted length, can be controlled. prior models neglected torsional twisting in the curved portions of the tubes. this paper presents a mechanics model that includes torsion, applies to any number of tubes and allows curvature and stiffness to vary with arc length. while the general model is comprised of differential equations, an analytic solution is given for two tubes of constant curvature. this solution enables analytic prediction of "snap through" instability based on a single dimensionless parameter. simulation and experiments are used to illustrate the results.
design of a semi-active knee prosthesis. current state-of-the-art prostheses for transfemoral amputees operate exclusively through controlled damping or through fully powered gait imitation. the passive devices cannot restore a natural gait, and the active devices are large and inefficient. this paper summarizes the design of a new semi-active prosthetic knee that combines the proven safety and power efficiency of a passively damped hydraulic device with the improved gait and advanced mobility of a fully active device.
step function based turning maneuvers in biomimetic robotic fish. this paper presents a new turning maneuver generation method for a multilink biomimetic robotic fish, in which smooth step functions are introduced to dynamically trigger directed offsets in active and asymmetric swimming. with the proposed method, three basic turning modes can be unified into a general framework by choosing appropriate step-function combinations and dynamic bias. furthermore, this method can be employed to maneuver the robotic fish agilely in the path planning, which promises more flexibility and steadiness in potential applications to bio-inspired autonomous underwater vehicles.
an optimized linear model predictive control solver for online walking motion generation. this article addresses the fast solution of a quadratic program underlying a linear model predictive control scheme that generates walking motions. we introduce an algorithm which is tailored to the particular requirements of this problem, and therefore able to solve it efficiently. different aspects of the algorithm are examined, its computational complexity is presented, and a numerical comparison with an existing state of the art solver is made. the approach presented here, extends to other general problems in a straightforward way.
design of human symbiotic robot twendy-one. in this paper, we propose a sophisticated design of human symbiotic robots that provide physical supports to the elderly such as attendant care with high-power and kitchen supports with dexterity while securing contact safety even if physical contact occurs with them. first of all, we made clear functional requirements for such a new generation robot, amounting to fifteen items to consolidate five significant functions such as "safety", "friendliness", "dexterity", "high-power" and "mobility". in addition, we set task scenes in daily life where support by robot is useful for old women living alone, in order to deduce specifications for the robot. based on them, we successfully developed a new generation of human symbiotic robot, twendy-one that has a head, trunk, dual arms with a compact passive mechanism, anthropomorphic dual hands with mechanical softness in joints and skins and an omni-wheeled vehicle. evaluation experiments focusing on attendant care and kitchen supports using twendy-one indicate that this new robot will be extremely useful to enhance quality of life for the elderly in the near future where human and robot co-exist.
pose estimation and adaptive robot behaviour for human-robot interaction. this paper introduces a new method to determine a person's pose based on laser range measurements. such estimates are typically a prerequisite for any human-aware robot navigation, which is the basis for effective and time-extended interaction between a mobile robot and a human. the robot uses observed information from a laser range finder to detect persons and their position relative to the robot. this information together with the motion of the robot itself is fed through a kalman filter, which utilizes a model of the human kinematic movement to produce an estimate of the person's pose. the resulting pose estimates are used to identify humans who wish to be approached and interacted with. the behaviour of the robot is based on adaptive potential functions adjusted accordingly such that the persons social spaces are respected. the method is tested in experiments that demonstrate the potential of the combined pose estimation and adaptive behaviour approach.
distributed coverage control for mobile sensors with location-dependent sensing models. this paper addresses the problem of coverage control of a network of mobile sensors. in the current literature, this is commonly formulated as a locational optimization problem under the assumption that sensing performance is independent of the locations of sensors. we extend this work to a more general framework where the sensor model is location-dependent. we propose a distributed control law and coordination algorithm. if the global sensing performance function is known a priori, we prove that the algorithm is guaranteed to converge. to validate this algorithm, we conduct experiments with indoor and outdoor deployments of cyclops cameras and model its sensing performance. this model is used to simulate deployments on 1d pathways and study the coverage obtained. we also examine the coverage in the case when the global sensing function is not known and is estimated in an online fashion.
person identification from human walking sequences using affine moment invariants. this paper proposes a new person identification method using physiological and behavioral biometrics. various person recognition systems have been proposed so far, and one of the recently introduced human characteristics for the person identification is gait. although the shape of one's body has not been considered much as a characteristic, it is closely related to gait and it is difficult to disassociate them. so, the proposed technique introduces a new hybrid biometric, combining body shape (physiological) and gait (behavioral). the new biometric is the full spatio-temporal volume carved by a person who walks. in addition to this biometric, we extract unique biometrics in individuals by the following way: creating the average image from the spatio-temporal volume and forming the new spatio-temporal volume from differential images which are created by subtracting an average image from original images. affine moment invariants are derived from these biometrics, and classified by a support vector machine. we used the leave-one-out cross validation technique to estimate the correct classification rate of 94%.
compact analysis of 3d bipedal gait using geometric dynamics of simplified models. the large number of degrees of freedom in legged robots give rise to complicated dynamics equations. analyzing these equations or using them for control can therefore be a difficult and non-intuitive task. a simplification of the complex multi-body dynamics can be achieved by instantaneously reducing it to an equivalent single inertial entity called the locked inertia or the composite rigid body inertia. in this paper, we adopt the methods of geometric dynamics to analyze the gait using the locked inertia of the robot. the analysis includes the rolling of a biped on a 3d rigid foot and 3d impacts. an example of numerical optimization of foot shape parameters is shown. our long-term objective is to develop the theoretical framework and to provide the necessary tools for systematic analysis, design, and control of efficient biped robots.
the curious robot - structuring interactive robot learning. if robots are to succeed in novel tasks, they must be able to learn from humans. to improve such human-robot interaction, a system is presented that provides dialog structure and engages the human in an exploratory teaching scenario. thereby, we specifically target untrained users, who are supported by mixed-initiative interaction using verbal and non-verbal modalities. we present the principles of dialog structuring based on an object learning and manipulation scenario. system development is following an interactive evaluation approach and we will present both an extensible, event-based interaction architecture to realize mixed-initiative and evaluation results based on a video-study of the system. we show that users benefit from the provided dialog structure to result in predictable and successful human-robot interaction.
a novel approach to path planning for multiple robots in bi-connected graphs. this paper addresses a problem of path planning for multiple robots. an abstraction where the environment for robots is modeled as an undirected graph with robots placed in its vertices is used (this abstraction is also known as the problem of pebble motion on graphs). a class of the problem with bi-connected graph and at least two unoccupied vertices is defined. a novel polynomial-time solution algorithm for this class of problem is proposed. it is shown in the paper that the new algorithm significantly outperforms the existing state-of-the-art techniques applicable to the problem. moreover, the performed experimental evaluation indicates that the new algorithm scales up well which make it suitable for practical problem solving.