waashk/dblp huggingface dataset:
development of grip-type master hand "meistergrip". we propose a novel grip-type master hand called meistergrip that measures grip force in terms of a force vector distribution. this device is expected to allow intuitive robot manipulation using vision-based haptic-sensing technology. furthermore, it can be used for general-purpose manipulation and is tolerant to individual differences in hand size and grasping posture. we constructed meistergrip and evaluated the accuracy of the measured grip force. furthermore, we constructed and exhibited a complete robot manipulation system using meistergrip to demonstrate the possibility of using meistergrip as a general-purpose master hand.
three-dimensional measurement of objects in water by using space encoding method. in this paper, a new method for 3-d measurement of objects in water is proposed. when observing objects in water through a camera contained in a waterproof housing or observing objects in an aquarium tank filled with preserving liquid, we should solve a problem of light refraction at the boundary surfaces of refractive index discontinuity which gives image distortion. the proposed method uses a space encoding method which does not have a problem of corresponding point detection as a stereo vision system has, and is faster than spot light projection or slit light projection methods. a ray tracing technique solves the problem of image distortion caused by refractive index discontinuity. it should be noted that monochromatic light projection onto objects gives more accurate measurement than white light projection because the refractive index depends on the wavelength of the light. then, in order to measure colored objects, we should project red, green and blue light patterns onto them separately. experimental results show the validity of the proposed method.
undulatory and pedundulatory robotic locomotion via direct and retrograde body waves. the present paper explores the effect of the mechanism-substrate frictional interface on the locomotion characteristics of robotic mechanisms employing traveling waves for propulsion. for these investigations, an extended class of undulatory robotic locomotors is considered, termed pedundulatory, which augment lateral body undulations by coordinated dorso-ventral oscillations of multiple pairs of lateral paddle-shaped appendages (parapodia). we examine how, the same robotic prototype, allows the implementation of four distinct bio-inspired undulatory and pedundulatory modes of locomotion, by modifying the motion control strategy depending on the mechanism-substrate frictional interface. these modes employ retrograde or direct body waves, either standalone (giving rise to eel-like and ochromonas-like undulatory locomotion modes, respectively), or combined with appropriately coordinated substrate contact by the parapodial appendages (giving rise to centipede-like and polychaete-like pedundulatory modes, respectively). these four modes are investigated and comparatively assessed, both in simulation and via extensive experiments on granular substrates with the nereisbot prototype. our results validate the identified locomotion principles and also highlight the enhanced performance and gait repertoire of pedundulatory systems, compared to purely undulatory ones.
a probabilistic sonar sensor model for robust localization of a small-size blimp in indoor environments using a particle filter. in recent years, autonomous miniature airships have gained increased interest in the robotics community. this is due to their ability to move safely and hover for extended periods of time. the major constraints of miniature airships come from their limited payload which introduces substantial constraints on their perceptional capabilities. in this paper, we consider the problem of localizing a miniature blimp with lightweight ultrasound sensors. since the opening angle of the sound cone emitted by a sonar sensor depends on the diameter of the membrane, small-size sonar devices introduce the problem of high uncertainty about which object has been perceived. we present a novel sensor model for ultrasound sensors with large opening angles that allows an autonomous blimp to robustly localize itself in a known environment using monte carlo localization. as we demonstrate in experiments with a real blimp, our novel sensor model outperforms a popular sensor model that has in the past been shown to work reliably on wheeled platforms.
modeling rfid signal strength and tag detection for localization and mapping. in recent years, there has been an increasing interest within the robotics community in investigating whether radio frequency identification (rfid) technology can be utilized to solve localization and mapping problems in the context of mobile robots. we present a novel sensor model which can be utilized for localizing rfid tags and for tracking a mobile agent moving through an rfid-equipped environment. the proposed probabilistic sensor model characterizes the received signal strength indication (rssi) information as well as the tag detection events to achieve a higher modeling accuracy compared to state-of-the-art models which deal with one of these aspects only. we furthermore propose a method that is able to bootstrap such a sensor model in a fully unsupervised fashion. real-world experiments demonstrate the effectiveness of our approach also in comparison to existing techniques.
optimized projection pattern supplementing stereo systems. stereo camera systems are widely used in many real applications including indoor and outdoor robotics. they are very easy to use and provide accurate depth estimates on well-textured scenes, but often fail when the scene does not have enough texture. it is possible to help the system work better in this situation by actively projecting certain light patterns to the scene to create artificial texture on the scene surface. the question we try to answer in ths paper is what would be the best pattern(s) to project. this paper introduces optimized projection patterns based on a novel concept of (symmetric) non-recurring de bruijn sequences, and describes algorithms to generate such sequences. a projected pattern creates an artificial texture which does not contain any duplicate patterns over epipolar lines within certain range, thus it makes the correspondence match simple and unique. the proposed patterns are compatible with most existing stereo algorithms, meaning that they can be used without any changes in the stereo algorithm and one can immediately get much denser depth estimates without any additional computational cost. it is also argued that the proposed patterns are optimal binary patterns, and finally a few experimental result using stereo and space-time stereo algorithms are presented.
movement primitives for three-legged locomotion over uneven terrain. we propose a framework for online generation of efficient gaits on uneven terrain. a set of dynamically optimal leg swing motion primitives for irregular terrains is first constructed offline-this is done by generating minimum torque motions for various starting and ending ground configurations, extracting dominant principal components, and forming basis functions. gaits are then generated online via linear interpolation of the principal component basis functions, using a distance metric on so(3) to select the components. the algorithm is verified via dynamic simulations involving the strider, a three legged passive-walking robot. our results show that gaits using only knee-actuated leg swings are able to traverse uneven terrain of bounded variation.
interference estimated time of arrival on a 6-dof cable-driven haptic foot platform. a cable-driven locomotion interface employs two independent cable-driven haptic foot platforms constrained in six degrees of freedom (6-dof). its control system and its geometry are designed for performing a wide range of trajectories that could generate cable interferences. this paper presents and analyzes computational methods for determining which cable can be released from an active actuation state while allowing control in a minimal tension state, thereby ensuring that both platforms stay in a controllable workspace. one challaging task is to develop light and fast computational algorithms for hard real time processes included in haptic display applications. seeing that releasing a cable from an active actuation state might generate discontinuities in tension values in the other cables, this paper proposes collision prediction schemes named interference estimated time of arrival in order to reduce or completely eliminate such discontinuities.
learning motor primitives for robotics. the acquisition and self-improvement of novel motor skills is among the most important problems in robotics. motor primitives offer one of the most promising frameworks for the application of machine learning techniques in this context. employing an improved form of the dynamic systems motor primitives originally introduced by ijspeert et al. [2], we show how both discrete and rhythmic tasks can be learned using a concerted approach of both imitation and reinforcement learning. for doing so, we present both learning algorithms and representations targeted for the practical application in robotics. furthermore, we show that it is possible to include a start-up phase in rhythmic primitives. we show that two new motor skills, i.e., ball-in-a-cup and ball-paddling, can be learned on a real barrett wam robot arm at a pace similar to human learning while achieving a significantly more reliable final performance.
vibration control of a multi-link flexible robot arm with fiber-bragg-grating sensors. flexible, lightweight manipulators offer some advantages in contrast to rigid arms, such as compact and lighter drives, energy efficiency, reduced masses and costs. this paper presents a novel approach for vibration damping of a multilink flexible arm. the strain of the elastic arms is measured with fiber-bragg-grating (fbg) sensors and provides the feedback signal to dampen their flexural dynamics. a dynamic model of a three link arm is derived that accounts for the rigid and flexural dynamics including gravity. the arm vibrations are damped by nonlinear strain feedback. the controller is general and robust and its design does not require a model of the flexural dynamics. in the context of closed loop vibration control fbg sensors offer a better signal to noise ratio compared to strain gauges, which allows a higher static gain in the feedback loop with more efficient dissipation of vibrational energy. the feasibility and effectiveness of the proposed vibration control scheme in conjunction with fbg sensors is verified and analyzed in simulations and confirmed in experiments with a flexible three link robot arm.
stereo vision and terrain modeling for quadruped robots. legged robots offer the potential to navigate highly challenging terrain, and there has recently been much progress in this area. however, a great deal of this recent work has operated under the assumption that either the robot has complete knowledge of its environment or that its environment is suitably regular so as to be navigated with only minimal perception, an unrealistic assumption in many real-world domains. in this paper we present an integrated perception and control system for a quadruped robot that allows it to perceive and traverse previously unseen, rugged terrain that includes large, irregular obstacles. a key element of the system is a novel terrain modeling algorithm, used for filling in the occluded models resulting from on-board vision systems. we apply our approach to the littledog robot, and show that it allows the robot to walk over challenging terrain using only on-board perception.
waalbot: agile climbing with synthetic fibrillar dry adhesives. this video presents a palm-size climbing robot which uses synthetic fibrillar dry adhesives inspired by geckos. with fibrillar footpads, the robot is shown to climb smooth surfaces such as glass and acrylic, and surfaces with micron-scale roughness such as wood. in particular, the agility of the robot is highlighted by demonstrations of climbing, steering, and plane-to-plane transitions.
reusable electronics and adaptable communication as implemented in the odin modular robot. this paper describes the electronics and communication system of odin, a novel heterogeneous modular robot made of links and joints. the electronics is divided into two printed circuit boards: a general board with reusable components and a specific board with non-reusable components. while the general board is common to the design of every type of module, such as power, actuator, sensor and structure, the specific board is unique to each type of module. the communication system, one of the most important reusable components of odin, is based on local buses that can be extended by bridging electrical signals. the implementations of actuator and power links show that splitting the electronics into general and specific boards allows rapid development of different types of modules, and an analysis of performance indicates that the communication system is simple, fast and flexible. as the electronic design reuses approx. 50% of components between two different types of modules, we find it convenient for heterogeneous modular robots where production costs demand a small set of parts. in addition, as the features of the communication system are desirable in modular robots, we think it is suitable for such systems as well as useful for future research into flexible network topologies.
parking with the essential matrix without short baseline degeneracies. this paper addresses the problem of visual control of a mobile robot. the system consists of a calibrated camera fixed onboard a robot with nonholonomic motion constraints. the parking task is defined by a reference image taken at the target location. the proposed control law is based on the essential matrix, but unlike traditional methods, it is not used to compute pose parameters. instead, the control law is defined directly in terms of individual entries of the essential matrix by means of the input-output linearization of the system. here we solve the problem of degeneracies due to short baseline by taking advantage of the planar motion constraint of the robot. thus, a virtual target is defined providing a stable estimation of the essential matrix without degeneracies despite short baseline.
capsular microrobot using directional friction spiral. most researches on internal mobile robot are going on based on the invasive clamping functions which generate the propulsion through a direct contact with organic tubes. this paper proposes a novel locomotion mechanism, which moves fundamentally based on a spiral profile and generates the additional force by transferring the rotational movement to the linear movement. the essence of proposed mobile microrobot is development of a rotation-linear movement interface mechanism and a non-invasive clamping function. this paper introduces the working principle and analyzes the behavior of mobile robot. finally we validate the performance of robot as non-invasive locomotion mechanism by experiments.
large motion range magnet levitation using a planar array of coils. we have formulated a method and implemented a device for magnetic levitation with a translation range which is at least twice as large as the dimensions of the levitated body in all directions. the motion range can be extended to any distance in the horizontal plane by adding more coils to the actuator array, and the rotation is potentially unlimited in all directions.
head motion stabilization during quadruped robot locomotion: combining dynamical systems and a genetic algorithm. the head shaking that results from robot locomotion is important because it difficults stable image acquisition and the possibility to rely on that information to act accordingly, for instance, to achieve visually-guided locomotion. in this article, we focus on the development of a head controller able to minimize the head motion induced by locomotion itself. specifically, we propose a combined approach to generate head movement stabilization on a quadruped robot, using central pattern generators (cpgs) and a genetic algorithm. head movement is generated by cpgs which are modelled as autonomous differential equations. this approach allows to explicitly specify parameters such as amplitude, offset and frequency of movement and to smoothly modulate the generated trajectories according to changes in these parameters. it is therefore easy to combine the cpg with an optimization method. a genetic algorithm determines the best set of parameters that generates the head movement that reduces the head shaking caused by locomotion. experimental results on a simulated aibo robot demonstrate that the proposed approach generates head movement that does not eliminate but reduces the one induced by locomotion.
stability / precision improvement of 6-dof visual servoing by motion feedforward compensation and experimental evaluation. this paper deals with position-based 6-dof visual servoing. with a common sense of feedback control, we stress that improvement of the dynamics of the sensing unit is important for a stable visual servoing. we propose a method to improve dynamics in visual recognition, with compensating the fictional motion of the target in the camera images based on kinematics of the manipulator, by extracting the real motion of the target. we named it as hand-eye motion feedforword (mff) method. the enhanced dynamics of recognition gave further stability and precision to the total visual servoing system, evaluated by full 6-dof servoing experiment using 7- link manipulator. the convergence time in step response was about 10[s] and precise visual servoing to a moving target object has been achieved.
non-grasp manipulation of deformable object by using pizza handling mechanism. this paper discusses the non-grasp dynamic manipulation of a deformable object inspired by the handling mechanism of pizza master. the master handles a tool where a plate is attached at the tip of a bar, and he remotely manipulates a pizza on the plate. we found that he aggressively utilizes two dofs (degrees of freedom), such that the linear motion along the bar and the rotational one around the bar, in order to produce quick plate motions for dynamically manipulating the object. applying this handling mechanism to the robot system, we first show how to rotate an object by using the two dofs of plate motion. we then reveal that the deformation of the object generated by dynamic effects can drastically contribute to high-speed and stable rotation, just like human steps for turn on the floor. by both simulation and experiment, we show that there exists the optimum plate motion leading to the maximum rotational speed of the object.
the airwand: design and characterization of a large-workspace haptic device. almost all commercially available haptic interfaces share a common pitfall, a small shoebox-sized workspace; these devices typically rely on rigid-link manipulator design concepts. in this paper we outline our design for a new kinesthetic haptic system that drastically increases the usable haptic workspace. we present a proof-of-concept prototype, along with our analysis of its capabilities. our design uses optical tracking to sense the position of the device, and air jet actuation to generate forces. by combining these two technologies, we are able to detach our device from the ground, thus sidestepping many problems that have plagued traditional haptic devices including workspace size, friction, and inertia. we show that optical tracking and air jet actuation successfully enable kinesthetic haptic interaction with virtual environments. given an appropriately large volume high-pressure air source, and a reasonably high speed tracking system, this design paradigm has many desirable qualities when compared to traditional haptic design schemes.
a compact soft actuator unit for small scale human friendly robots. this paper presents the development of a new compact soft actuation unit intended to be used in multi degree of freedom and small scale robotic systems such as the child humanoid robot "icub" [1]. compared to the other existing series elastic linear or rotary implementations the proposed design shows high integration density and wider passive deflection. the miniaturization of the newly developed high performance unit was achieved with a use of a new rotary spring module based on a novel arrangement of linear springs. the model and the control scheme of the actuator are analysed. the proposed control scheme is a velocity based controller that generates command signals based on the desired simulated stiffness using the spring deflection state. the overall system is evaluated with experimental trials performed using a prototype unit. preliminary results are presented to show that the unit and the proposed control scheme are capable of replicating virtual impedances within a wide range and with good fidelity.
model and parameter identification of friction during robotic insertion of cochlear-implant electrode arrays. robot-assisted cochlear implant surgery was proposed and proved to be efficient in reducing insertion forces on acrylic scala tympani models. during experiments, the authors discovered that the insertion force not only depends on the shape discrepancy between the scala tympani and the inserted electrode array, but also on the insertion speed. this paper presents a friction model that describes the whole insertion process and investigates the relationship between the insertion speed and the insertion force. experimental and statistical results show the effectiveness of the model. applying the friction model generates safety insertion force boundaries for future insertions and gives the optimal insertion speed. it also provides predictive force information for insertion speed feedback control law design which may be applied to robot-assisted cochlear implant surgeries.
object classification based on a geometric grammar with a range camera. this paper proposes an object classification framework based on a geometric grammar aimed for mobile robotic applications. the paper first discusses the geometric grammar as a compact representation form for object categories with primitive parts as its constituent elements. the paper then discusses the object classification implemented as parsing of primitive parts. in particular, two approaches are discussed that constrain the search space in order to render the parsing of the primitive parts practical. the two approaches are experimentally verified, first, for a generic object category of chair applied to real range images acquired with a range camera mounted on a mobile robot and, second, for multiple generic object categories applied to synthetic range images. the experimental results show the practicability of the framework.
study of a 2-dof joint for the small active cord mechanism. the active cord mechanism (acm) such as a snake-like robot is suitable for tasks in a narrow environment because of its slender body, but mechanical models developed in prior research were somewhat large for practical usage. in this paper, we propose a new 2-dof joint mechanism for the small acm. a usual joint mechanism has the same number of rotational axes as that of the actuators, but the proposed mechanism has 4 rotation axes against 2 actuators. this joint mechanism has relatively large range of motion and it can improve the capability of acm in a narrow environment. we verified the specification of the proposed mechanism and the result showed that it is suitable for the small acm. in addition, we developed the acm with the proposed joint mechanism, and it realized a sidewinding motion, which is a kind of snakes' locomotion style. we think this result shows that the proposed mechanism will contribute to the study of the small acm.