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A nonlinear inertial-aided image-based visual servo control approach for the stabilization of (almost) fully actuated autonomous underwater vehicles (AUVs) is proposed. It makes use of the homography matrix between two images of a planar scene as feedback information while the system dynamics are exploited in a cascade manner in a control design: An outer-loop control defines a reference setpoint...
This paper presents a generalised framework of an image based visual servoing of an articulated arm which has to be deployed inside a simulated Tokamak vessel environment. First wall tiles of the vessel idealised as rectangular grids on a surface are inspected and an attempt is made to replace the damaged tiles with a tile-screwing gripper mechanism. The mechanism of gripper provides compactness and...
Real time and non invasive, the ultrasound imaging modality can easily be used in minimally invasive surgery or needle insertion procedures to visualize an organ or a tumor to reach. However the manual stabilization of the ultrasound image while the organ moves with patient breathing or heart beating can be very tricky. In this paper, we present an intensity-based approach to control both in-plane...
Personal robots anticipated to become popular in the future are required to be active in joint work and community life with humans. These personal robots must recognize changing environment and must conduct adequate actions like human. Visual tracking can be said as a fundamental function from the view point of environmental sensing and reflex reaction against it. The authors developed a visual tracking...
In this paper we present a framework for combining force and visual feedback in the task space to deal with humanoid interaction tasks like open doors in a real kitchen environment. We present stereo-vision methods for markerless recognition and estimation of environmetal elements for applying force control strategies for compliant execution using a 6D force-torque sensor mounted in the humanoids's...
IAUV (Intervention Autonomous Underwater Vehicle) is a main direction for AUV's future development. An important feature for IAUV is the capability of autonomous underwater docking. On this other hand, underwater vision in IAUV is gaining increasing attention nowadays. To achieve a high reliable, optimized docking system, a guiding system for docking based on the philosophy of visual dynamic positioning...
Image based methods are a new approach for solving problems in mobile robotics. Instead of building a metric (3D) model of the environment, these methods work directly in the sensor (image) space. The environment is represented as a topological graph in which each node contains an image taken at some pose in the workspace, and edges connect poses between which a simple path exists. This type of representation...
This paper focuses on visual servoing from a special target using a vision sensor with an unique projection center. The target is a sphere marked with two points on its surface. Using a spherical projection model, a new minimal set of six features is proposed for this target. Spherical moments are exploited to compute the new set on the image of the sensor. Using the new set, a classical control method...
This paper is concerned with the use of a spherical projection model to design optimal visual features for visual servoing. Here two special targets are considered: a sphere marked with two points on its surface and a sphere marked with a tangent vector to a point on its surface. For these targets we propose a new minimal set of six visual features which can be computed on classical perspective cameras...
In this paper we present an experimental evaluation of automatic robotic assembly of complex planar parts. The torque-controlled DLR light-weight robot, equipped with an on-board camera (eye-in-hand configuration), is committed with the task of looking for given parts on a table, picking them, and inserting them inside the corresponding holes on a movable plate. Visual servoing techniques are used...
This paper presents a new and effective multisensor based control strategy for high-accuracy/precision and high-efficiency automatic robot localization and calibration. The strategy combines both coarsely visual servo and fine position-sensitive detector (PSD) servo control methods. In a large field of view, an image-based visual servo control system is developed to roughly guide the laser beam, which...
This paper presents a multivariable open-loop model for visual servoing of robot manipulators using image based strategy. The modeling considers the dynamics of the velocity controlled robot as well as a model of the visual sensor that consists of camera and feature extraction block. Taking into account the velocity dynamics with internal feedback loops, a linearized and decoupled model of the joints...
This paper investigated the visual servoing regulation of nonholonomic mobile robots with monocular camera. Nonholonomic kinematic systems with visual feedback are uncertain and more involved in comparison with common kinematic systems. Two-step techniques were used to presented a robust controller that enables the mobile robot image pose and the orientation regulation despite the lack of depth information...
Sensor-based robot control allows manipulation in dynamic environments with uncertainties. Vision offers a low-cost sensor modality, but low sample rate, high sensor delay and uncertain measurements limit its usability. This paper addresses three problems: uncertain visual measurements, different sampling rates and compensation of the sensor delay. To alleviate the problems above an approach for visual...
This paper presents a dynamic simulation model for visual servoing of a robot manipulator using image based strategy. The modeling takes into account the dynamics of the camera velocity inner loop as well as a model of the visual sensor that consists of the camera and feature extraction block. Considering the inner loop and the visual sensor models, the dynamic simulation model of the visual servo...
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