this article addresses the visual servoing of a rigid robotic manipulator under fixed camera configuration. A laser pointer is mounted on the end-effector of a robot whose orientation can be controlled by automatic vi...
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(纸本)0780377362
this article addresses the visual servoing of a rigid robotic manipulator under fixed camera configuration. A laser pointer is mounted on the end-effector of a robot whose orientation can be controlled by automatic visual feedback. the control goal is to drive the laser spot to follow a visually determined planar contour by using a single-camera vision system. In this research, image-based control approach is proposed to achieve "precise" positioning in the absence of measurement noise. Withthis system, one can achieve automatic planar contour following using approximately calibrated single-camera vision. the control strategy is successfully validated in a real-time PC-based experimental system by performing experiments on arbitrary contour following.
We analyze the problem of finding the optimal placement of tracked primitives for robust vision-based control of a mobile robot. the analysis evaluates the properties of the Image Jacobian matrix, used for direct gene...
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ISBN:
(纸本)0780377362
We analyze the problem of finding the optimal placement of tracked primitives for robust vision-based control of a mobile robot. the analysis evaluates the properties of the Image Jacobian matrix, used for direct generation of the control signals from the error signal in the image, and the accuracy of the underlying sensor system. the analysis is then used to select optimal tracking primitives that ensure good observability and controllability of the mobile system for a variety of sensor system configurations. the theoretical results are validated with our mobile robot for system configurations that use standard video cameras mounted on a pan-tilt head and catadioptric systems.
Teleoperation makes possible the execution of many tasks, that otherwise are not feasible when a human operator can not access to the working area due to dangerousness or environmental conditions, and it is not possib...
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ISBN:
(纸本)0780377362
Teleoperation makes possible the execution of many tasks, that otherwise are not feasible when a human operator can not access to the working area due to dangerousness or environmental conditions, and it is not possible as well, to program the task so as to be performed autonomously, due to its complexity. Nevertheless, manipulation tasks require certain ability from the human operator due to the difficulties that produce the need to operate through control devices that does not fit withthe structure of the slave arms. Withthe aim of increasing the precision capabilities provided by such control interfaces, a vision based procedure designed to deform the space around the working point has been developed. the vision system operates from the detection of the relevant scene elements. this space deformation produces automatically a progressive increase in precision when the robot arm approaches the relevant detected elements.
In this paper, we develop the switching controller presented by Lee et al. [14] for the pose control of a car-like vehicle, to allow the use of an omnidirectional vision sensor. To this end we incorporate an extension...
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ISBN:
(纸本)0780377362
In this paper, we develop the switching controller presented by Lee et al. [14] for the pose control of a car-like vehicle, to allow the use of an omnidirectional vision sensor. To this end we incorporate an extension to a hypothesis on the navigation behaviour of the desert ant, cataglyphis bicolor, which leads to a correspondence free landmark based vision technique. the method we present allows positioning to a learnt location based on feature bearing angle and range discrepancies between the robot's current view of the environment, and that at a learnt location. We present simulations and experimental results, the latter obtained using our outdoor mobile platform.
We have developed a humanoid robot HRP-2P with a biped locomotion controller, stereo vision software and aural human interface to realize cooperative works by a human and a humanoid robot. the robot can find a target ...
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ISBN:
(纸本)0780377362
We have developed a humanoid robot HRP-2P with a biped locomotion controller, stereo vision software and aural human interface to realize cooperative works by a human and a humanoid robot. the robot can find a target object by the vision, and carry it cooperatively with a human by biped locomotion according to the voice commands by the human. A cooperative control is applied to the arms of the robot while it. carries the object, and the walking direction of the robot is controlled by the interactive force and torque through the force/torque sensor on the wrists. the experimental results are presented in the paper.
Like oral communication, gestures are a natural way to carry out Human Machine Interface. In the early days of robotic systems, human gesture was used to control robot movements by means of a master-slave structure. I...
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ISBN:
(纸本)0780377362
Like oral communication, gestures are a natural way to carry out Human Machine Interface. In the early days of robotic systems, human gesture was used to control robot movements by means of a master-slave structure. In spite of the use of robot programming languages, manual control is the most reliable way to carry out complex tasks in unstructured environments. In these situations, a non-contact, passive and remote system can be helpful to control a teleoperated robot by means of human gestures. In this paper, a vision system able to detect, locate and track the head and hands of a human body is presented. the system uses several calibrated cameras placed around the operator scenario to locate the body parts of a person in 3D. the system combines different computer vision techniques to increase the reliability of the body parts detection: image movement detection, user skin colour segmentation and stereo. the data provided by these modules are fused looking for coherence according to the human body dimensions. Withthe scheme proposed it is possible to obtain a low-cost real-time system for human computer interfacing based in a natural way of communication (gestures). Civil area such as big robots in shipyards, mines, public works or cranes are some possible applications.
We consider the problem of having a team of nonholonomic mobile robots follow a desired leader-follower formation using omnidirectional vision. By specifying the desired formation in the image plane, we translate the ...
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ISBN:
(纸本)0780377362
We consider the problem of having a team of nonholonomic mobile robots follow a desired leader-follower formation using omnidirectional vision. By specifying the desired formation in the image plane, we translate the control problem into a separate visual servoing task for each follower. We use a rank constraint on the omnidirectional optical flows across multiple frames to estimate the position and velocities of the leaders in the image plane of each follower. We show that the direct feedback-linearization of the leader-follower dynamics suffers from degenerate configurations due to the nonholonomic constraints of the robots and the nonlinearity of the omnidirectional projection model. We therefore design a nonlinear tracking controller that avoids such degenerate configurations, while preserving the formation input-to-state stability. Our control law naturally incorporates collision avoidance by exploiting the geometry of omnidirectional cameras. We present simulations and experiments evaluating our omnidirectional vision-based formation control scheme.
the objective of this project, named MESIA (Multifunctional Micro-Endoscope Head System for Industrial Applications) is to develop an integrated multi-sensor system and to create intelligent sensor fusion for detectio...
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ISBN:
(纸本)0780377362
the objective of this project, named MESIA (Multifunctional Micro-Endoscope Head System for Industrial Applications) is to develop an integrated multi-sensor system and to create intelligent sensor fusion for detection of micro-cracks. this paper is focused on the modeling of a 2-DOF pan-tilt platform actuated by Ni-Ti shape memory alloy (SMA) wires and antagonistic mechanical springs in order to control visually the CCD camera motion. A Preisach model is used and experimentally identified. the derived model is then exploited to design a position controller which compensates for the hysteretic nonlinearity. Finally, by controlling the catheter head orientation through a head motion tracker, in-pipe visual tracking has been experimentally verified from a remote site.
the application of robots in contact with humans, in services or assistance, implies the realization of effective and acceptable human-robot interaction. In humans, vision plays a significant role in social interactio...
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ISBN:
(纸本)0780377362
the application of robots in contact with humans, in services or assistance, implies the realization of effective and acceptable human-robot interaction. In humans, vision plays a significant role in social interaction, like for example in the recognition of faces and expressions, as well as in gesture understanding. Visuo-motor coordination of eye and neck movements in humans presents high performances in terms of accuracy, speed, effectiveness. this is due to the mechanical, cinematic, and dynamic features of the head muscular-skeletal apparatus and to the peculiar processing of visual data, detected with a space variant resolution. the work presented in this paper aims at employing retina-like cameras on a human-like robotic head, reproducing similar degrees of freedom, ranges of motion, speeds, and accelerations of human neck and eye movements, in order to improve visuo-motor coordination. the use of retina-like cameras allows a faster human-like processing of visual information, better suited for the control of head movements. On the other hand, retina-like cameras provide high resolution information only in a small area of the image and thus need to be dynamically focused on the points of interest. Experimental trials were focused on the capability of identifying and tracking human faces, as a first step of human-robot interaction. Preliminary experimental results show the feasibility of a smooth face tracking, by a closed control loop for the head movements, based on retina-like vision.
A new flexible parts feeding system has been designed and constructed at Case Western Reserve University. To complement the feeder, an object-oriented software architecture has been designed and implemented. Design go...
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ISBN:
(纸本)0780377362
A new flexible parts feeding system has been designed and constructed at Case Western Reserve University. To complement the feeder, an object-oriented software architecture has been designed and implemented. Design goals of the software were the ability to rapidly introduce a new part into the system without major reprogramming and the creation of a software architecture that would be applicable to the general class of vision-based parts feeders (rather than just our own implementation). the system currently feeds two different types of parts and can switch on-the-fly between part types. throughputs in excess of 60 parts per minute have been achieved during testing.
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