waashk/dblp huggingface dataset:
what to do and how to do it: translating natural language directives into temporal and dynamic logic representation for goal management and action execution. robots that can be given instructions in spoken language need to be able to parse a natural language utterance quickly, determine its meaning, generate a goal representation from it, check whether the new goal conflicts with existing goals, and if acceptable, produce an action sequence to achieve the new goal (ideally being sensitive to the existing goals). in this paper, we describe an integrated robotic architecture that can achieve the above steps by translating natural language instructions incrementally and simultaneously into formal logical goal description and action languages, which can be used both to reason about the achievability of a goal as well as to generate new action scripts to pursue the goal. we demonstrate the implementation of our approach on a robot taking spoken natural language instructions in an office environment.
robust velocity sliding mode control of mobile wheeled inverted pendulum systems. there has been an increasing interest in a kind of underactuated mechanical systems, mobile wheeled inverted pendulum (mwip) models, which are widely used in the field of autonomous robotics and intelligent vehicles. robust velocity tracking problem of mwip systems is investigated in this study. in the velocity control problem, model uncertainties accompany uncertain equilibriums, which make the controller design become more difficult. a sliding mode control (smc) method based on a novel sliding surface is proposed for the systems, which are capable of handling both parameter uncertainties and external disturbances. by assuming the specially designed sliding surface, the proposed smc controller is capable of eliminating the steady velocity tracking error. the asymptotical stability of the closed-loop system is achieved through selecting sliding surface parameters in terms of some rules. the effectiveness of the proposed methods is finally confirmed by numerical simulations.
effects of geometric imperfections to the control of redundantly actuated parallel manipulators. the model-based control of robotic manipulators relies on an exact model of the manipulator. redundantly actuated pkm posses the ability to exhibit internal prestress that does not affect its environment. this allows for a purposeful distribution of control forces, taking into account secondary tasks, such optimal force distribution, active stiffness, and backlash avoiding control. in the presence of kinematic uncertainties this feature can become a serious problem since then the control forces may be annihilated or even some of the intentional prestress components may interfere with the environment. the effect of such kinematic uncertainties and the application of standard model-based control schemes is analyzed in this paper. it is shown that, in the presence of model uncertainties, it leads to parasitic perturbation forces that can not be compensated by the controls. an amended version of the augmented pd and computed torque control scheme is proposed that removes the parasitic feedback forces.
1000 trials: an empirically validated end effector that robustly grasps objects from the floor. unstructured, human environments present great challenges and opportunities for robotic manipulation and grasping. robots that reliably grasp household objects with unknown or uncertain properties would be especially useful, since these robots could better generalize their capabilities across the wide variety of objects found within domestic environments. within this paper, we address the problem of picking up an object sitting on a plane in isolation, as can occur when someone drops an object on the floor - a common problem for motor-impaired individuals. we assume that the robot has the ability to coarsely position itself in front of the object, but otherwise grasps the object with an open-loop strategy that does not vary from object to object. we present a novel end effector that is capable of robustly picking up a diverse array of everyday handheld objects given these conditions. this straight-forward, inexpensive, nonprehensile end effector combines a compliant finger with a thin planar component with a leading wedge that slides underneath the object. we empirically validated the efficacy of this design through a set of 1096 trials over which we systematically varied the object location, object type, object configuration, and floor characteristics. our implementation, which we mounted on a irobot create, had a success rate of 94.71% on 680 trials, which used 4 floor types with 34 objects of particular relevance to assistive applications in 5 different poses each (4×34×5=680). the robot also had strong performance with objects that would be difficult to grasp using a traditional end effector, such as a dollar bill, a pill, a cloth, a credit card, a coin, keys, and a watch. prior to this test, we performed 416 trials in order to assess the performance of the end effector with respect to variations in object position.
on the generation of feasible paths for aerial robots with limited climb angle. this paper presents a methodology based on a variation of the quintic pythagorean hodographs curves for generating smooth feasible paths for autonomous vehicles in three-dimensional space under the restriction of limited climb angles. a given path is considered feasible if the main kinematic constraints of the vehicle are not violated. the generated paths satisfy three main angular constraints: (i) maximum curvature, (ii) maximum torsion and (iii) maximum climb (or dive). the smoothness the vehicle acceleration profile is indirectly guaranteed between two consecutive points of the profile. the proposed methodology is applicable to vehicles that move in three-dimensional environments, and that can be modelled under the constraints assumed. we apply our methodology and show the results for a small autonomous aerial vehicle.
t-hive : vibrotactile interface presenting spatial information on handle surface. many recent studies have explored the use of tactile cues, however they were confined to the unilateral display device. although lots of bilateral haptic devices have been developed to provide a guiding force on an input handle, however, a vibrotactile stimuli has not been tried to present directional information on the handle. this research introduces an attempt to combine a tactile display with an input device. a new 6dof bilateral haptic device, which provides a spatial sensation on the handle using vibrotactile display, is proposed in this research. the sphere-shape handle is specially designed to be covered with several pieces of vibrating panels. when a specific panel is activated, the user perceives the spatial location of the vibrotactile stimulus during an input operation. this paper introduces the design of the proposed device, including the selection guide of the dimension, location, and number of vibrotactile panels. the method for combination of vibrotactile stimulus and the way to achieve fine resolution with small number of tactors are discussed. experimental results show that the users can reliably perceive the directional information using the proposed device. an application for teleoperation of a robot proves the effectiveness and the usefulness of the proposed bilateral device.
physiological motion rejection in flexible endoscopy using visual servoing and repetitive control : improvements on non-periodic reference tracking and non-periodic disturbance rejection. flexible endoscopes are used in many surgical procedures and diagnostic exams. they have also been used recently for new surgical procedures using natural orifices called notes. while these procedures are really promising for the patients, they are really awkward for the surgeons. in order to assist the surgeon, physiological motion cancellation has been successfully applied on a robotized endoscope in [8] by using a prototype repetitive controller (prc) and a repetitive generalized predictive controller (r-gpc). both controllers showed to be powerful tools to cancel periodic disturbances but with poor transient response to non-periodic disturbances. contrary to the r-gpc, the prc is unsuitable for handling non-periodic reference changes. we propose in this paper, as a first improvement, a model-based control scheme using the prc which allows to decouple the reference tracking from the periodic output disturbance rejection. the response to nonperiodic disturbance is also improved by this technique but a repetition appears caused by the repetitive controller. as a second improvement, a switching control scheme is proposed to avoid the repetition.
realization of cylinder climbing locomotion with helical form by a snake robot with passive wheels. recently, multiple locomotion gaits of snake have been realized by snake robots. however, previous locomotion gaits are mainly limited on two-dimensional plane. in this study, we make a snake robot that can move in three-dimensional space by connecting several units serially. the each unit is composed by assembling one pitch axis and one yaw axis, and it can have two passive wheels. we realize previously achieved basic locomotion gaits and simple cylinder climbing locomotion. in addition, we also realize cylinder climbing locomotion with helical form by the snake robot using mathematical continuum model.
time-minimal path planning in dynamic current fields. numerous approaches have been proposed for path planning in dynamic current fields, for a fixed departure time. however, in many applications, the departure time is not necessarily known in advance, but can vary in a time window. in this context, the choice of a good departure time is a critical issue. that is why we introduce in this paper a new approach, called symbolic wavefront expansion, determining both the path and the departure time minimizing the travel time of the vehicle. the key idea of this approach is to propagate and compose functions instead of numerical values, with appropriate operators.
active multi-view object search on a humanoid head. visual search is a common daily human activity and a prerequisite to the interaction with objects encountered in cluttered environments. humanoid robots that are supposed to take part in human daily life should possess similar capabilities in terms of representing, attending to and recalling objects of interest in order to ensure robust perception in human-centered environments. in this paper, we present necessary processes, memories and representations which allow to identify and store locations of objects, encountered from different angles of view, in a visual search task. in particular, we introduce the so-called feature ego-sphere (fes) as the scene memory for a humanoid robot. experiments comprising different visual search tasks have been carried out on an active humanoid head equipped with perspective and foveal stereo camera systems. the scene is analyzed actively using both camera systems in order to find instances of searched objects in a consistent and persistent manner.
3d model-based 6-dof head tracking by a single camera for human-robot interaction. in human-robot interaction, it is important for the robot to know the head movement, gaze direction and expression of the conversation partner, since such information are deeply related with the attention, intention and emotion. recently, many types of real-time measurement systems for head pose and gaze direction have been proposed and utilized for human interfaces and ergonomics applications. we have proposed a face measurement system which is non-contact and passive by utilizing a stereo camera pair. however the necessity of the use of stereo camera has several drawbacks. to cope with this problem, this paper proposes a method to measure the 6 dof motions of the head by utilizing a single camera. the use of 3d face model enables us to predict six 2d motion vector fields of facial features which correspond to six unit motions in translation and rotation. an actual 2d motion vector field obtained by tracking facial features is then resolved into a linear combination of the predicted six motion vector fields. the estimated 6 dof motions can be obtained as the six coefficients of the linear combination. through the evaluation of the implemented motion estimation method, it was shown that the accuracy of the proposed estimation method using a single camera was comparable with that of the conventional method using a stereo camera pair. finally developed face tracking system is demonstrated by a humanoid robot interacting with two persons, which takes advantage of the wide field of view of the camera system due to the unnecessity of the stereoscopy.
developing a product quality fault detection scheme. in current semiconductor and tft-lcd factories, periodic sampling is commonly adopted to monitor the stability of manufacturing processes and the quality of products (or workpieces). as for those non-sampled workpieces, their quality is usually monitored by such as a fault-detection-and-classification (fdc) server. however, this method may fail to detect defected products. for example, a workpiece with all the individual manufacturing process parameters being in-spec may still result in out-of-spec product quality. under this circumstance, unless this certain defected workpiece is selected for sampling by chance, it cannot be detected by simply monitoring the manufacturing process parameters collected from the production equipment. to solve the abovementioned problem, this research proposes a product quality fault detection scheme (fds), which utilizes the classification and regression tree to implement a model for identifying the relationship between process parameters and out-of-spec products. through this model, each set of normal manufacturing process parameters can be real-time and on-line examined to detect failure or defected products.
adaptive triangular mesh generation of self-configuring robot swarms. we address the problem of dispersing a large number of autonomous mobile robots toward building wireless ad hoc sensor networks performing environmental monitoring and control. for the purpose, we propose the adaptive triangular mesh generation algorithm that enables robots to generate triangular meshes of various sizes adapting to changing environmental conditions. a locally interacting, geometric technique allows robots to generate each triangular mesh with their two neighbor robots. specifically, we have assumed that robots are not allowed to have the identifier, any pre-determined leaders or common coordinate systems, and any explicit communication. under such minimal conditions, the positions of the robots were shown to converge to the desired distribution, which was mathematically proven and also verified through extensive simulations. our preliminary results indicate that the proposed algorithm can be applied to the problem regarding the coverage of an area of interest by a swarm of mobile sensors.
equitable partitioning policies for robotic networks. the most widely applied resource allocation strategy is to balance, or equalize, the total workload assigned to each resource. in mobile multi-agent systems, this principle directly leads to equitable partitioning policies in which (i) the workspace is divided into subregions of equal measure, (ii) there is a bijective correspondence between agents and subregions, and (iii) each agent is responsible for service requests originating within its own subregion. in this paper, we provide the first distributed algorithm that provably allows m agents to converge to an equitable partition of the workspace, from any initial configuration, i.e., globally. our approach is related to the classic lloyd algorithm, and provides novel insights into the properties of power diagrams. simulation results are presented and discussed.
rational systems and matrix inequalities to the multicriteria analysis of visual servos. this paper outlines a generic method to the analysis of eye-in-hand position-based or image-based visual servos. a side from convergence, the fulfillment of additional important criteria can be assessed, e.g. the target visibility, the avoidance of actuators' saturations, and the guarantee of 3d constraints. the field of nonlinear "rational" systems is first shown to constitute a sound and versatile framework to the problem. the fundamentals of a solution based on lyapunov theory are overviewed next, together with the noteworthy difficulties raised by robotics. constructive results are finally sketched out, in terms of a feasibility/optimization program subject to matrix inequalities. a case study illustrates the approach.
learning sequential visual attention control through dynamic state space discretization. similar to humans and primates, artificial creatures like robots are limited in terms of allocation of their resources to huge sensory and perceptual information. serial processing mechanisms used in the design of such creatures demands engineering attentional control mechanisms. in this paper, we present a new algorithm for learning top-down sequential visual attention control for agents acting in interactive environments. our method is based on the key idea, that attention can be learned best in concert with visual representations through automatic construction and discretization of the visual state space. the tree representing the top-down attention is incrementally refined whenever aliasing occurs by selecting the most appropriate saccadic direction. the proposed approach is evaluated on action-based object recognition and urban navigation tasks, where obtained results support applicability and usefulness of developed saccade movement method for robotics.
regulation control of underactuated mechanical systems based on a new matching equation of port-controlled hamiltonian systems. we consider the control of port-controlled hamiltonian (pch) systems, which are a generalization of euler-lagrange systems. a new matching equation for pch systems is developed so that interconnection damping assignment passivity-based control (ida-pbc) can be extended to the regulation of some underactuated pch systems whose kinetic energy must be modified. a simple underactuated mechanical system (the inertial wheel pendulum) is used to demonstrate the effectiveness of the proposed method.
robobuntu: a linux distribution for mobile robotics. during last years linux started to climb the market of operating systems (oss), and ubuntu, derived by debian os, has become a good alternative to common oss like windows xp or vista. the mobile robotics scientific community makes use of linux based oss to avoid the lack of stability that affects microsoft oss, especially when real time conditions must be satisfied. in this paper we present the linux distribution robobuntu, acronym formed by the union of robot and ubuntu, to overcome the almost totally independent robotic software platforms existing today. the key idea behind robobuntu is the integration of different tools for mobile robotics into an embedded ubuntu distribution. another important characteristics of robobuntu is that every "hard step", like installation and configuration of os and tools, is hidden to common users. in particular, robobuntu can be used either by students or researchers, as livecd, permanent installation on standard hard drive or, more interesting, on a usb storage flash disk.
motion compensation for robotic-assisted surgery with force feedback. the paper presents a control architecture for robotic-assisted surgery in the presence of physiological motions. dynamic and kinematic models, operational space, computed torque, discrete state space and stochastic design are addressed in the control. inner loops are based on position and velocity signals and outer loops have force measurements. two active observers (aobs) are introduced for force control and motion compensation. the first aob is responsible for model-reference adaptive control to guarantee a desired closed loop dynamics for the force. the second aob performs control actions to compensate physiological motions. such motions are described by a second-order stochastic equation, without apriori knowledge of signal characteristics. simulation results are presented for sinusoidal and non-sinusoidal motions, highlighting merits of the approach.
specialization as an optimal strategy under varying external conditions. we present an investigation of specialization when considering the execution of collaborative tasks by a robot swarm. specifically, we consider the stick-pulling problem first proposed by martinoli et al. [1], [2] and develop a macroscopic analytical model for the swarm executing a set of tasks that require the collaboration of two robots. we show, for constant external conditions, maximum productivity can be achieved by a single species swarm with carefully chosen operational parameters. while the same applies for a two species swarm, we show how specialization is a strategy best employed for changing external conditions.
on computing robust n-finger force-closure grasps of 3d objects. the paper deals with computing frictional force-closure grasps of 3d objects problem. the key idea of the presented work is the demonstration that wrenches associated to any three non-aligned contact points of 3d objects form a basis of their corresponding wrench space. this result permits the formulation of a new sufficient force-closure test. our approach works with general objects, modelled with a set of points, and with any number n of contacts (n ≥ 4). a quality criterion is also introduced. a corresponding algorithm for computing robust force-closure grasps has been developed. its efficiency is confirmed by comparing it to the classical convexhull method [26].
appearance-based loop detection from 3d laser data using the normal distributions transform. we propose a new approach to appearance based loop detection from metric 3d maps, exploiting the ndt surface representation. locations are described with feature histograms based on surface orientation and smoothness, and loop closure can be detected by matching feature histograms. we also present a quantitative performance evaluation using two real-world data sets, showing that the proposed method works well in different environments.
combined yaw and roll control of an autonomous boat. in this paper we try to develop a host-based system and study actual sea trials via rudder based roll control method. to authors' best knowledge, the boat we investigated is the smallest among those reported in the literature. an autonomous boat model is obtained by a system identification approach. the identified system is designed with frequency-shaped sliding mode control. the control scheme is composed of a sliding mode observer and a sliding mode controller. the stability and reachability of the switching function are proved by lyapunov theory. computer simulations and experiment show that successful course keeping and roll reduction results are achieved.
extending itasc to support inequality constraints and non-instantaneous task specification. in [1], we presented our constraint-based programming approach, itasc, that formulates instantaneous sensor-based robot tasks as constraint sets, and subsequently solves a corresponding least-squares problem to obtain control set points, such as desired joint velocities or joint torques. this paper further extends this approach, (i) by explicitly supporting the inclusion of inequality constraints in the task and (ii) by supporting a broader class of objective functions for translating the task constraints into robot motion. these extensions are made while retaining a tractable mathematical problem structure (a convex program). furthermore, first results on extending the approach to non-instantaneous tasks are presented. as illustrated in the paper, the power of the approach lies (i) at its versatility to specify a wide range of robot behaviors and the ease of making task adjustments, and (ii) at its generic nature, that permits using systematic procedures to derive the underlying control equations.