Explosion in Internet applications has stimulated active research activities in expanding the capability of the current telecommunication networks. These activities include implementing faster electronics to process t...
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ISBN:
(纸本)0780374002
Explosion in Internet applications has stimulated active research activities in expanding the capability of the current telecommunication networks. These activities include implementing faster electronics to process the higher data bit rates, or developing wavelength division multiplexing (WDM) techniques, and novel optical networks components to increase the information carrying capacity of the optical networks. As the data bit rates increases, it will become increasingly difficult to implement an electronic switching fabric solution. It is known that the information carrying laser beams should be dealt with at the optical level. One of most promising optical network components is micromachined optical cross connect switches. We present a new crossbar switching design methodology that decreases the number of mirrors and electrodes needed while maintaining the same non-blocking port switching capability. More importantly, this new architecture also reduces the distance of free-space propagation of light beams, thus reducing the loss due to Guassian-beam divergence during free-space propagation of light.
Modeling in biological systems is important at every level from the molecular, to the cellular, to the tissue level. In this paper we discuss the following problem in molecular modeling: given a three-dimensional conf...
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Modeling in biological systems is important at every level from the molecular, to the cellular, to the tissue level. In this paper we discuss the following problem in molecular modeling: given a three-dimensional conformation of a molecule, how do we automatially compute the conformations of the molecule that satisfy certain spatial constraints, that is, certain "feature" atoms of the molecule are in user-specified positions? This task is important in the analysis of receptor-ligand interactions and in other applications such as drug design and protein folding. Using an analogy between robots and molecules, we use the term inverse kinematics to describe the above conformational problems. To solve these problems, we first derive a system of polynomial equations. Then, we adopt a technique based on the Groebner basis from algebraic geometry and develop a novel subdivision algorithm to approximate the real solutions. The approximated solutions can then be used as the starting conformations for existing (heuristic) energy minimization procedures that try to satisfy the target positions of feature atoms and reduce the overall energy of the conformation. To our knowledge, this is the first time that a rigorous algebraic methodology has been used to approximate molecular inverse kinematics solutions.
Human navigational principles are researched and applied to mobile robotic applications. Two principles, constant optical rate and angular constancy, can be used by a fielder or mobile robot to define a trajectory for...
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ISBN:
(纸本)0780365763
Human navigational principles are researched and applied to mobile robotic applications. Two principles, constant optical rate and angular constancy, can be used by a fielder or mobile robot to define a trajectory for interception of a projectile without knowledge of the ball's or fielder's world coordinates. Two novel, robust, viewer-centered algorithms, a passive and an active version, are modeled and experimentally validated.
Process monitoring is the key to an increasing degree of automation and consequently to an increasing productivity in manufacturing. The realization of process monitoring functionality demands an extension of the cont...
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ISBN:
(纸本)0780365763
Process monitoring is the key to an increasing degree of automation and consequently to an increasing productivity in manufacturing. The realization of process monitoring functionality demands an extension of the control system. The prerequisite for these extensions are open interfaces in the NC-kernel. Nowadays controls with open NC-kernel interfaces are available on the market. However these interfaces are vendor specific solution that do not allow the reuse of monitoring software in different controls. To overcome these limitations a vendor neutral open real-time interface for the integration of process monitoring functionality into the NC-kernel is presented in this paper. Additionally two implementations of the real-time interface for different target systems are described.
Workpiece localization has direct relations with many manufacturing automationapplications. In order to gain accurate workpiece measurement by coordinate measuring machines (CMM) or on-machine measurement system, the...
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ISBN:
(纸本)0780365763
Workpiece localization has direct relations with many manufacturing automationapplications. In order to gain accurate workpiece measurement by coordinate measuring machines (CMM) or on-machine measurement system, the touch trigger probe is widely adopted. In spite of the high repeatability of the touch trigger probe, there are still error sources associated with the probe. In this paper, we will focus on probe radius compensation. Several compensation methods in related papers are reviewed. In addition, a new radius compensation method is proposed in this paper. Simulation and experimental results of probe radius compensation by different methods are given. It is shown that our proposed method has the best performance both in terms of compensation accuracy and computational time. The method is also implemented in a computer aided setup (CAS) system.
In a companion paper [1] we have developed a framework for rating or comparing navigation packages. For a given environment a navigation package consists of a motion planner and a sensor to be used during navigation, ...
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ISBN:
(纸本)0780365763
In a companion paper [1] we have developed a framework for rating or comparing navigation packages. For a given environment a navigation package consists of a motion planner and a sensor to be used during navigation, The ability to rate or measure a navigation package is important in order to address issues like sensor customization for an environment and choice of a motion planner in an environment. In this paper we present the algorithm which we use in order to rate a given navigation package. Under the framework which was presented in [1], a partially observable Markov decision process (POMDP) is defined. The algorithm searches for an optimal policy to be employed in this decision process. We briefly review the problem and the framework, develop the algorithm and present experimental results.
In space applications. it is conceivable that part of (lie robotic activities could involve the grasp and/or manipulation of free-floating objects in absence of gravity. In this case, synchronous application of contac...
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ISBN:
(纸本)0780365763
In space applications. it is conceivable that part of (lie robotic activities could involve the grasp and/or manipulation of free-floating objects in absence of gravity. In this case, synchronous application of contacts seems to represent a basic feature in order to efficiently grasp the floating items. In this sense, an additional difficulty is that objects may have irregular shape and/or be non well positioned in the gripper workspace. These difficulties cannot be handled in a simple way with standard 2-jaw,, grippers, with one (or two) degrees of freedom. In this paper, an activity for designing and experimenting a gripper for this type of operations is reported. and the first laboratory results arc, presented and discussed. Main features of the gripper are its kinematic configuration (3 fingers with 3 dof) and its sensorial equipment, features that improve the dexterity of this device if compared to more classical devices.
Cable array robots are a class of robotic mechanisms which utilize multiple actuated cables to manipulate objects. This paper discusses the defining characteristics and the important issues relating to this class of r...
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ISBN:
(纸本)0780365763
Cable array robots are a class of robotic mechanisms which utilize multiple actuated cables to manipulate objects. This paper discusses the defining characteristics and the important issues relating to this class of robots. One particular type of cable array robot with three cables is presented in detail including kinematic relations and dynamic modeling. The resulting models are used to design a sliding mode control system for the robot, providing robustness to uncertainty in the mass of manipulated objects while tracking a given trajectory. Experimental results are provided for the system, showing that the robot is capable of tracking a trajectory within several centimeters, which is reasonable performance for many industrial applications. These results are discussed in detail and future research plans are presented.
Because the elderly population is growing while the number of people to take care of them is declining, ive propose an Internet telerobotic system to assist the aged or disabled in their homes when their caregivers (i...
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ISBN:
(纸本)0780365763
Because the elderly population is growing while the number of people to take care of them is declining, ive propose an Internet telerobotic system to assist the aged or disabled in their homes when their caregivers (ire away. In this paper we analyze typical teleoperation robotic, systems and design an Internet telerobotic system using CORBA (Common Object Request Broker Architecture). We detail the systems features, architecture, find implementation. The proposed system gives users the ability to control the robotic system remotely by an intuitive user interface. The client can transparently invoke methods on the application servers across the network without knowing where the application servers are located, what programming language the application is written in, or what operating system is being used This is because, in developing and implementing the system, CORBA for the distributed, object-oriented applications was used.
This paper discusses the robotic acquisition and characterization of surface friction and roughness for real-world objects. Our motivation is the construction of detailed "reality-based" models for existing ...
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ISBN:
(纸本)0780365763
This paper discusses the robotic acquisition and characterization of surface friction and roughness for real-world objects. Our motivation is the construction of detailed "reality-based" models for existing objects that can be used in haptic displays and other applications involving simulation. A key challenge addressed in this paper is the acquisition of these surface properties on real objects with non-trivial shape, and registration of these properties with respect to geometric models of the shape, We show how Coulomb friction may be effectively estimated in the presence of variations in surface normal. We also show how to estimate a stochastic process model of surface roughness. Finally, we demonstrate the robotic mapping of surface friction over an entire object, using the UBC Active Measurement Facility (ACME.).
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