Wavelet and shearlet-based image representations for visual servoing (original) (raw)
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Proceedings 2000 ICRA. Millennium Conference. IEEE International Conference on Robotics and Automation. Symposia Proceedings (Cat. No.00CH37065)
We describe in this paper potential problems that may appear in image-based visual servoing when the initial camera position is far away from its desired position. We show by concrete examples that local minima or a singularity of the image Jacobian can be reached during the servoing. We then recall recent results obtained to avoid these drawbacks. It consists in combining visual features obtained directly from the image, and position-based features. This approach, called 2 1/2 D visual servoing, also provides supplementary advantages in function of the mean the features are combined with.
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2002
This paper is concerned with choosing image features for image based visual servo control and how this choice influences the closed-loop dynamics of the system. In prior work, image features tend to be chosen on the basis of image processing simplicity and noise sensitivity. In this paper we show that the choice of feature directly influences the closed-loop dynamics in task-space. We focus on the depth axis control of a visual servo system and compare analytically various approaches that have been reported recently in the literature. The theoretical predictions are verified by experiment.
Robust image-based visual servoing using invariant visual information
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Proceedings 2006 IEEE International Conference on Robotics and Automation, 2006. ICRA 2006., 2006
Robotized ultrasound examination offers on one hand more accuracy for the medical diagnostic and on the other hand a suitable assistance to radiologists. In the literature, very few researches deal with ultrasound image-based control of a medical robot holding the ultrasound probe. This paper presents a new visual servoing approach allowing the automatic guidance of the ultrasound probe. This technique is based on the modeling of the coupling between the ultrasound probe and egg shaped objects. The robotic task consists in reaching a desired image from an arbitrary initial position. The aim of this task is to assist the radiologist diagnostic by automatically moving the ultrasound probe in order to find the ultrasound image view of a tumour cross-section registered in a previous date. This work presents simulation results of the proposed ultrasound visionbased control scheme.
Use of first derivative of geometric features in visual servoing
1996
Visual servoing is based on an array of measurements taken from a set of images and used each time as an error function to compute a control vector. This is applied to the system (robot and camera) and makes it move in order to reach a desired situation, at the end of the task, directly depicted in the image. The originality of this recent work consists in improving the visual servoing approach. To do this, we consider a signal sensor vector constructed of a geometrical feature ((x,y) point coordinates, line parameters, etc.) and its first derivative. In this paper, we show how to work out the interaction matrix. We have tested this new approach on a workstation in the case of the point feature. We have also implemented it on our robotic platform. The overall results show a great improvement due to the action of this new signal sensor. We are extending this approach to more complex features
A Brief Comparative Study of Visual Servoing Systems
IJSRD - International Journal for Scientific Research & Development, 2018
This paper presents an overview of visual servoing systems. The basic structure of a visual servoing system, various controller techniques used and the comparison of the techniques being used is a matter of concerned of the paper. The paper concentrates on different visual servoing techniques like: image based, position based and hybrid visual servo control, for different issues concerning both hardware and software requirements.
II. DEFINITION OF THE SUBJECT AND ITS IMPORTANCE Control systems that use information acquired from an imaging source in the feedback loop are defined as visual servo control systems. Visual servo control has developed into a large subset of robotics literature because of the enabling capabilities it can provide for autonomy. The use of an image sensor for feedback is motivated by autonomous task execution in an unstructured or unknown environments.
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2005 IEEE/RSJ International Conference on Intelligent Robots and Systems, 2005
A new visual servoing technique based on 2D ultrasound image is proposed in order to control the motion of an ultrasound probe held by a medical robot. In opposition to a standard camera which provides a projection of the 3D scene to a 2D image, ultrasound information is strictly in the observation plan of the probe and consequently visual servoing
Analysis of classical and new visual servoing control laws
2008 IEEE International Conference on Robotics and Automation, 2008
In this paper, we analyze and compare five imagebased visual servoing control laws. Three of them are classical while two new ones are proposed. The first new control law is based on a behavior controller to adjust the movement of the camera. It can also be used to switch between the classical methods. The second control law is designed to try to obtain the global stability of the system. An analytical study of all control schemes when translational motion along and rotational motion around the optical axis is also presented. Finally, simulation and experimental results show that the new control law with a behavior controller has a wider range of success than the other control schemes and can be used to avoid local minima and singularities.