The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
In the image-based visual servoing framework, error signals are directly computed from image feature parameters, thus obtaining control schemes which do not need neither a 3-D model of the scene, nor a perfect knowledge of the camera calibration matrix. However, the current value of the depth Z for each considered feature must be known. We propose a method to estimate on-line the value of Z for point...
This paper presents a method to incorporate 3D line segments in vision based SLAM. A landmark initialization method that relies on the Plucker coordinates to represent a 3D line is introduced: a Gaussian sum approximates the feature initial state and is updated as new observations are gathered by the camera. Once initialized, the landmarks state is estimated along an EKF-based SLAM approach: constraints...
In this paper, a vision based tracking controller with adaptation to uncertainty in depth information is presented. Depth uncertainty plays a special role in visual tracking as it appears nonlinearly in the overall Jacobian matrix and hence cannot be adapted together with other uncertain kinematic parameters. We propose a novel parameter update law to update the uncertain parameters of the depth....
In this paper, we proposes a visual servoing method that approximates the relation between the variations of image points and the variations of a stereo rig in Euclidian space. As with most image-based visual servoing methods, commands are expressed in the space of image features. However, instead of relating instantaneous image-based variations to instantaneous variations in Euclidian space, the...
We describe two new sampling strategies for Rao-Blackwellized particle filtering SLAM. The strategies, called fixed-lag roughening and the block proposal distribution, both exploit "future" information, when it becomes available, to improve the filter's estimation for previous time steps. Fixed-lag roughening perturbs trajectory samples over a fixed lag time according to a Markov chain-Monte...
This paper presents a method of 3D SLAM using a single camera. We utilize a Rao-Blackwellised particle filter (RBPF) to deal with a large number of landmarks. A difficulty in monocular SLAM is robustness to outliers and noise, which may cause false estimates especially under short baseline conditions. We propose an exhaustive pose-space search that finds all the plausible hypotheses efficiently using...
An emotional robot is regarded as being able to express its diverse emotions in response to internal or external events. This paper presents a robot affective system that is able to express life-like emotions. In order to do that, the overall architecture of our affective system is based on neuroscience from which we obtained the natural emotional processing routines. Based on that architecture, we...
Humanoid robots as assistance or educational robots is an important research topic in the field of robotics. Especially the communication of those robots with a human operator is a complex task since more than 60% of human communication is conducted non-verbally by using facial expressions and gestures. Although several humanoid robots have been designed it is unclear how a control architecture can...
This paper presents a force feedback control scheme for the compensation of periodic motions of organs induced by respiration or heartbeat in minimally invasive robotized surgery. It applies surgical tasks involving a contact between an instrument and a moving organ. It is well known that conventional force control allows for compensating the motion of the environment thanks to its natural disturbance...
This paper presents a method of integrating kinematic mechanism design and hybrid system analysis for the design of a single-degree-of-freedom (DOF) planar biped robot that can achieve dynamic walking gaits that are stable. Reducing the DOF in a biped can result in a reduction of the complexity of the control strategies needed to enable stable walking. Although the biped designed by this procedure...
This paper discusses the design principles and philosophy of the BiMASC, a biped with mechanically adjustable series compliance which incorporates tuned mechanical leg springs. This robot will be capable of dynamic running using mechanical leg springs, as well as dynamic ballistic walking with human-like passive leg swing behavior. The BiMASC will enable the study of the role of both controllable...
This paper presents a simple stabilizing control scheme for the rolling sphere. A tracking control problem with respect to a "virtual moving trajectory" is first solved. Then, it is used to achieve practical stability for the regulation problem. The derived controllers have a simple form and can guarantee fast convergence. To verify the effectiveness of the proposed results, an interesting...
The paper presents a genetic algorithm to find and optimize solutions for nonholonomic motion planning problems. Mainly focusing on mobile robots, the algorithm uses present randomized algorithms to come up with suboptimal paths and iteratively optimizes them according to a fitness function which includes domain specific knowledge. The major advantages of this method include being an any-time algorithm,...
Prior papers have introduced steerable needles composed of precurved concentric tubes. The curvature and extent of these needles can be controlled by the relative rotation and translation of the individual tubes. Under certain assumptions on the geometry and design of these needles, the forward kinematics problem can be solved in closed form by means of algebraic equations. The inverse kinematics...
This paper presents a control architecture for artificial muscle materials such as shape memory alloys and polymer actuators. The active material is broken up into many small independent cells that can be regulated in a binary fashion into ON and OFF states, so that the actuator displacement is determined by the number of ON cells. In order to control the number of cells that contract, a novel closed...
We introduce a distributed compliant device inspired in gecko foot. It consists of a holder and small independent adhesion units on a flexible support. Unlike gecko, that uses Van der Waals force to achieve adhesion, the proposed design can be based on other adhesion phenomena, (for example magnetic or electrostatic force). We evaluate an implementation based on magnets. Key features are: limited...
Currently, over seven million people die of cancer each year; some of whom suffer from pain caused by bone metastasis. In their final stages of life, the pain is such that they cannot even roll over, one of the activities of daily life. With this in mind, in this research, we aim to develop equipment for patients with cancer bone metastasis to support roll-overs in terminal care. Specifically, the...
The purpose of the present study is to control human biological rhythm and life cycle by optimization of awakening timing. We developed a wearable interface for controlling awakening time named "BRAC (biological rhythm based awakening timing controller)". BRAC could estimate bio-rhythm by pulse wave from finger tip and send awake signal to user. An ordinary alarm clock operates according...
Parallel manipulators might be severely damaged while crossing parallel singularities, because the actuator forces required to keep the platform on a given trajectory might approach infinity. It is thus important to know whether a desired pose of the platform in the workspace can be reached through a singularity-free path or not, and, in the first case, which path should be followed. This paper presents...
This paper discusses an optimum design approach for robotic hands by considering the characteristics of visco-elasticity of food. "Norimaki-sushi" is taken as an example for food. We first show that the dynamic characteristics of such food can be expressed by utilizing the Maxwell model with two layers. Based on dynamic parameters obtained by experiments, we show the relationship among the...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.