A robotic system is presented which automatically pots (i.e., sinks) pool balls. A homography is estimated that relates the gantry robot coordinate frame to the overhead (global) camera coordinate frame. This homograp...
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A robotic system is presented which automatically pots (i.e., sinks) pool balls. A homography is estimated that relates the gantry robot coordinate frame to the overhead (global) camera coordinate frame. This homography is computed by first calculating the mapping between the camera frame and a projection of the robot frame, and then solving the pool table plane equation in the robot frame. A measurement technique has been developed which is based upon a local camera attached to the robot end effector. This local camera allows the robot to be positioned accurately over circular targets placed on the table. The homography and table plane equation are then estimated by establishing correspondences between at least 4 measured target positions in the global camera and robot frames. The resulting homography allows the gantry to be positioned to within an average of 0.6 mm of a global camera frame position over the extent of a full sized pool table. The system has been used to pot a ball with 67% accuracy over the extent of the table, with a high repeatability.
A novel self-sensing thermal actuator incorporating a micromirror is proposed as a fine positioning actuator for the precise-tracking mechanism of a high-density optical drive. Due to the bimorph effect, a bilayer can...
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A novel self-sensing thermal actuator incorporating a micromirror is proposed as a fine positioning actuator for the precise-tracking mechanism of a high-density optical drive. Due to the bimorph effect, a bilayer cantilever, consisting of two materials with different thermal expansion, can provide force or displacement with change in temperature. In the proposed thermal actuator, an integrated micromirror suspended by four identical thermal bilayer cantilevers is vertically driven to move upwards by a driving voltage. Meanwhile, the mirror position can be detected by an embedded high-sensitivity piezoresistive sensor. The process flow of the self-sensing actuator is presented with the prototypes. The experimental results show that the micromirror can be driven up to an equivalent 1.4 /spl mu/m displacement in the tracking direction by the driving voltage of 3 V. The device also has a measured resonant frequency of 7 kHz and displacement sensitivity of 0.04 ppm//spl Aring/ to support high bandwidth servo feedback control in an optical drive.
SWENET, the network community for software engineering education, is an NSF funded project to develop curriculum modules of value to faculty members desiring to incorporate software engineering concepts in new or exis...
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SWENET, the network community for software engineering education, is an NSF funded project to develop curriculum modules of value to faculty members desiring to incorporate software engineering concepts in new or existing courses. By design, the modules are self-contained instructional units ranging from a single lecture to approximately one week of course material. In this way, instructors can adopt, adapt, and arrange modules as appropriate to their courses. This presentation will provide an update on the status of the project including a report of current progress and problems encountered. The session will also address the future of the course materials collection and solicit input on ways to provide ongoing support to the community of software engineering researchers.
The paper proposes digital beamforming algorithms for vestigial sideband (VSB) based digital TV (DTV) receivers. We consider two types of beamforming algorithms, based on selection and adaptive beamforming algorithms....
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ISBN:
(纸本)0780382552
The paper proposes digital beamforming algorithms for vestigial sideband (VSB) based digital TV (DTV) receivers. We consider two types of beamforming algorithms, based on selection and adaptive beamforming algorithms. In the selection beamforming scheme, we make N fixed beams and select one. To do this, we compare the correlations of the received signal through each fixed beam with the pilot symbols. In the adaptive beamforming scheme, we use the least mean square algorithm to get beamforming weights. To be applicable to the VSB system, we modify the standard beamforming algorithms used in cellular communication systems. To apply these algorithms, we have developed a simple VSB system simulator including VSB modulator, synchronizers, and an equalizer. In the VSB modulator, we use the Hilbert transform and the raised-cosine filter. In the synchronizers, we implement the Gardner detector to recover timing synchronization. We use a decision-feedback equalizer. We demonstrate the performance of the proposed system under the Brazil channel model, and show that the beamforming algorithms can improve the overall system performance matching with other parts in the simulation.
The paper proposes a new digital beamforming algorithm for vestigial sideband (VSB) based digital TV receivers. We consider a selection beamforming (SBF) algorithm combined with a spatial equalizer. To realize this, w...
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ISBN:
(纸本)0780385217
The paper proposes a new digital beamforming algorithm for vestigial sideband (VSB) based digital TV receivers. We consider a selection beamforming (SBF) algorithm combined with a spatial equalizer. To realize this, we make fixed beams for the SBF. We then select several beams which satisfy some criteria. We put them into the spatial equalizer. In the SBF, we mitigate the effect of multipath. This helps the synchronizer operating in the channel where the multipath signals are strong. To reduce the multipath component, which still exists in the beams due to the beam-pattern sidelobe, we choose some beams and combine them based on the least mean squares algorithm. To apply this algorithm, we have developed a simple VSB system simulator including VSB modulator. synchronizers, and an equalizer. We show that the proposed algorithms can improve the overall system performance, matching with other parts in the simulation.
We discuss the design and implementation of an integrated media creation environment, and demonstrate its efficacy in the generation of two simple home movies. The significance for the average user seeking to create h...
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We discuss the design and implementation of an integrated media creation environment, and demonstrate its efficacy in the generation of two simple home movies. The significance for the average user seeking to create home movies lies in the flexible and automatic application of film principles to the task, removal of tedious low-level editing by means of well-formed media transformations in terms of high-level film constructs (e.g. tempo), and content repurposing powered by those same transformations added to the rich semantic information maintained at each phase of the process
This paper details the design and implementation of the (/spl alpha/, t) protocol for ad-hoc networks on Linux. The (/spl alpha/, t) protocol utilizes adaptive clustering to organize nodes into clusters in which the p...
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This paper details the design and implementation of the (/spl alpha/, t) protocol for ad-hoc networks on Linux. The (/spl alpha/, t) protocol utilizes adaptive clustering to organize nodes into clusters in which the probability of path failure due to node movement can be bounded over time. Based on the (/spl alpha/, t) cluster scheme, routes within clusters are maintained on a proactive basis while routing between clusters is maintained on a reactive basis.
In this paper, we solve the problem of excitation of plasma oscillations in 2D electron layer selfconsistently using the full system of the Maxwell equations. We formulate this problem as the problem of diffraction of...
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In this paper, we solve the problem of excitation of plasma oscillations in 2D electron layer selfconsistently using the full system of the Maxwell equations. We formulate this problem as the problem of diffraction of the incoming plane electromagnetic wave on a gate electrode.
We analyze two software rejuvenation policies of cluster server systems under varying workload, called fixed rejuvenation and delayed rejuvenation. In order to achieve a higher average throughput, we propose the delay...
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We analyze two software rejuvenation policies of cluster server systems under varying workload, called fixed rejuvenation and delayed rejuvenation. In order to achieve a higher average throughput, we propose the delayed rejuvenation policy, which postpones the rejuvenation of individual nodes until off-peak hours. Analytic models using the well known paradigm of Markov chains are used. Since the size of the Markov model is nontrivial, automated specification generation, and the solution via stochastic Petri nets is utilized. Deterministic time to trigger rejuvenation is approximated by a 20-stage Erlangian distribution. Based on the numerical solutions of the models, we find that under the given context, although the fixed rejuvenation occasionally yields a higher throughput, the delayed rejuvenation policy seems to outperform fixed rejuvenation policy by up to 11%. We also compare the steady-state system availabilities of these two rejuvenation policies.
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