A projective homography is developed by relating feature points extracted from images taken at the reference and current camera position/orientation. By decomposing the homography into translation and rotation compone...
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A projective homography is developed by relating feature points extracted from images taken at the reference and current camera position/orientation. By decomposing the homography into translation and rotation components, geometric relationships are determined that facilitate the construction of an adaptive strategy to identify unknown depth information. The development of the parameter identification strategy provides a mechanism to develop a position-based and a hybrid position/image-based visual servo controller for a trajectory tracking control problem. By using information obtained from the parameter identification strategy, both visual servoing controllers are proven to yield exponential tracking.
In this paper, a continuous estimator strategy is utilized to asymptotically identify the six degree-of-freedom velocity of a moving object using a single fixed camera. The design of the estimator is facilitated by th...
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ISBN:
(纸本)0780379241
In this paper, a continuous estimator strategy is utilized to asymptotically identify the six degree-of-freedom velocity of a moving object using a single fixed camera. The design of the estimator is facilitated by the fusion of homography-based techniques with Lyapunov design methods. Similar to the stereo vision paradigm, the proposed estimator utilizes different views of the object from a single camera to calculate 3D information from 2D images. In contrast to some of the previous work in this area, no explicit model is used to describe the movement of the object; rather, the estimator is constructed based on bounds on the object's velocity, acceleration, and jerk.
In recent papers, a new class of model-free (i.e., the 3-dimensional task-space model of the object is unknown) visual servoing methods was proposed that are based on the estimation of the relative camera orientation ...
ISBN:
(纸本)0780379241
In recent papers, a new class of model-free (i.e., the 3-dimensional task-space model of the object is unknown) visual servoing methods was proposed that are based on the estimation of the relative camera orientation between two views of an object. By utilizing homography-based techniques, the control problem is decoupled by separating the rotation and translation components. A single controller is used to control the rotation component, and the class members consist of various translation controllers. Each of the current class members has been proven to yield asymptotic regulation in the presence of uncertainty in the intrinsic and extrinsic calibration parameters. New control development and stability analysis techniques are crafted in this paper to develop a new translation controller that yields exponential rotation and translation regulation in the presence of uncertainty in the intrinsic and extrinsic calibration parameters. Extensions to this research can be used to yield exponential regulation by the other translation controllers in the asymptotic class presented.
As more and more companies are relying on their suppliers to provide raw materials or component parts, effective coordination and inventory management of supply chain members became critical issues. Various methods in...
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As more and more companies are relying on their suppliers to provide raw materials or component parts, effective coordination and inventory management of supply chain members became critical issues. Various methods including information sharing and postponing strategy have been explored to improve supply chain performance. However, questions regarding what information to share and the benefits under different conditions for different members are not fully understood. This paper presents a simulation study on a three-level infinite capacity supply chain through a systematic design of experiments. Independent variables include lead times, information sharing patterns, demand uncertainties, and service levels. It is shown through the analysis of means and the analysis of variance that one-way full information sharing is sufficient to achieve good performance. The types of benefit received by different members, however, are different. Furthermore, as more information is shared, the benefit from postponing customization decreases.
In this paper, the 3-dimensional (3D) position and orientation of a camera held by the end-effector of a robot manipulator is regulated to a constant desired position and orientation despite (i) the lack of depth info...
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In this paper, the 3-dimensional (3D) position and orientation of a camera held by the end-effector of a robot manipulator is regulated to a constant desired position and orientation despite (i) the lack of depth information of the actual or desired camera position from a target, (ii) the lack of a geometric model of the target object, and (iii) uncertainty regarding both the angle and axis of rotation of the camera with respect to the robot end-effector (i.e., the orientation extrinsic camera parameters). By fusing 2D image-space and projected 3D task-space information (i.e., 2.5D visual servoing), a robust controller is developed that ensures exponential regulation of the position and orientation of the camera. The stability of the controller is proven through a Lyapunov-based analysis.
In this paper, a new continuous observer is developed to determine range information (and hence the 3-dimensional (3D) coordinates) of an object feature moving with affine motion dynamics (or the more general Riccati ...
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In this paper, a new continuous observer is developed to determine range information (and hence the 3-dimensional (3D) coordinates) of an object feature moving with affine motion dynamics (or the more general Riccati motion dynamics) with known motion parameters. The unmeasurable range information is determined from a single camera provided an observability condition is satisfied that has physical significance. To develop the observer, the perspective system is expressed in terms of the nonlinear feature dynamics. The structure of the proposed observer is inspired by recent disturbance observer results. The proposed technique facilitates a Lyapunov-based analysis that is less complex than the sliding-mode based analysis derived for recent discontinuous observer designs. The analysis demonstrates that the 3D task-space coordinates of the feature point can be asymptotically identified.
Mobile robot teams are increasingly deployed in various applications involving remote operations in unstructured environments that do not support wireless network infrastructures. We propose a class of protocols based...
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Mobile robot teams are increasingly deployed in various applications involving remote operations in unstructured environments that do not support wireless network infrastructures. We propose a class of protocols based on the connectivity-through-time concepts that exploit the robot movements to extend the traditional notions of network connectivity. These protocols enable the formation of adhoc networks of mobile robots without the infrastructure of access points by utilizing the robots as routers. These protocols are implemented as a collection of daemons that track connectivity changes, compute single and multiple hop connectivity, route the packets via robots with suitable buffering, and adapt the transport parameters to the connection characteristics. The implementation employs UDP with window-based flow control that is tuned to the nature of connections. We present experimental performance results based on our implementation on robot teams to illustrate the salient features of this approach.
Automatic CAD-guided optimal tool planning has many application in surface manufacturing, such as spray painting, spray forming, rapid tooling, cleaning and polishing. A general framework for CAD-guided optimal tool p...
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ISBN:
(纸本)0780378601
Automatic CAD-guided optimal tool planning has many application in surface manufacturing, such as spray painting, spray forming, rapid tooling, cleaning and polishing. A general framework for CAD-guided optimal tool planning is developed to automatically generate optimal trajectories for these tasks. A material distribution model is developed. A multi-objective constraint optimization problem is formulated. An optimal tool trajectory with an optimal time and material quantity deviation is generated. Simulations are performed to verify the generated trajectory. The results show that the developed optimal tool planning algorithm can be applied to generate optimal tool trajectories. This framework can also be extended to other applications.
We investigated the relationship between the intracranial pulse pressure (ICP/sub PP/) and the mean intracranial pressure (ICP/sub M/). In adult patients, several research groups have described a linear relationship b...
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We investigated the relationship between the intracranial pulse pressure (ICP/sub PP/) and the mean intracranial pressure (ICP/sub M/). In adult patients, several research groups have described a linear relationship between ICP/sub PP/ and ICP/sub M/ within the range of cerebral autoregulation. Current monitoring and therapy are mainly based on the mean ICP/sub M/, since it is believed that the ICP/sub M/ contains most of the information provided by the other pulse morphology metrics. In this paper we attempt to answer whether there is further information within the ICP morphology not explained by ICP/sub M/ that might be of prognostic significance. We screened ICP records of 42 patients admitted to the Pediatric Intensive Care Unit at Doernbecher Children's Hospital for segments in which the ICP/sub M/ varied at least 5 mmHg during a 1-hour period. We found 54 segments in 9 different pediatric TBI patients (ages 0.2-17.8 years, mean=9.9 years). ICP/sub PP/ and ICP/sub M/ were calculated for each pulse using an automatic pressure detection algorithm. The coefficient of linear correlation r was > 0.70 in 43/54 segments (p < 0.001), which indicates that there exists a linear relationship between ICP/sub PP/ and ICP/sub M/. However, we found r > 0.90 only in 16/54 segments (p=NS) . This result and visual inspection of ICP/sub PP/ vs. ICP/sub M/ density plots suggest that ICP pulse pressure is not fully explained by the ICP M.
作者：
Abd-Almageed, WaelSmith, ChristopherRobotics
Artificial Intelligence and Vision Laboratory Electrical and Computer Engineering Department University of New Mexico United States
In this paper, a new technique for object classification from silhouettes is presented. Hidden Markov Models are used as a classification mechanism. Through a set of experiments, we show the validity of our approach a...
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ISBN:
(纸本)1889335185
In this paper, a new technique for object classification from silhouettes is presented. Hidden Markov Models are used as a classification mechanism. Through a set of experiments, we show the validity of our approach and show its invariance under severe rotation conditions. Also, a comparison with other techniques that use Hidden Markov Models for object classification from silhouettes is presented.
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