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Develop improved battery charger (Turbo-Z Battery Charging System). Final report

Description: The output of this project was a flexible control board. The control board can be used to control a variety of rapid battery chargers. The control module will reduce development cost of rapid battery charging hardware. In addition, PEPCO's proprietary battery charging software have been pre-programmed into the control microprocessor. This product is being applied to the proprietary capacitive charging system now under development.
Date: September 1, 1999
Partner: UNT Libraries Government Documents Department

Computer simulation studies of parabolic interpolation circuitry

Description: A computer-simulation study of parabolic interpolation circuitry for machine tool controllers was completed. Results showed that a tool center can be moved along any parabolic arc to within any realistic tolerance. Circuit design requirements were determined and input data required by the parabolic interpolators were defined. Simulation results showed that tool motion along a pronounced parabolic path would stay within a 1/2-microinch tolerance. An application of the parabolic interpolation toward reducing the large input data volumes required by conventional numerical controllers was achieved. (auth)
Date: December 28, 1973
Creator: Davenport, C.M.
Partner: UNT Libraries Government Documents Department

Test of a magnetic device for the amelioration of scale formation at Treatment Facility D

Description: A commercial device (Descal-A-Matic{reg_sign}, Norfolk, VA) designed to treat water by means of a magnetic field has been evaluated for its effect on the formation of calcite scale at LLNL Treatment Facility D. At this facility, volatile organic contaminants (VOCs) are removed by air stripping, which raises the water pH, causing the deposition of calcium carbonate as calcite scale downstream. To evaluate the magnetic treatment technique, the ground water was passed through the Descal-A-Matic{reg_sign} device before treatment by the air stripping unit, and the resulting scale formation and other water characteristics were compared with those found during a test with no water treatment and a test with chemical treatment with a polyphosphate additive. No beneficial effect was found when using the magnetic device. 6 refs., 6 figs., 4 tabs.
Date: December 1, 1996
Creator: Krauter, P.W., Harrar, J.E., Orloff, S.P., Bahowick, S.M. & Bahowick, S. M.
Partner: UNT Libraries Government Documents Department

Fundamental Power Couplers for Superconducting Cavities

Description: Fundamental power couplers (FPC's) for superconducting cavities must meet very strict requirements to perform at high power levels (hundreds of kilowatts) and in a variety of conditions (CS, pulsed, travelling wave, standing wave) without adversely affecting the performance of the cavities they are powering. Producing good coupler designs and achieving operational performances in accelerator environments are challenging tasks that have traditionally involved large resources from many laboratories. The designs involve state-of-the-art activities in RF, cryogenic and mechanical engineering, materials science, vacuum technology, and electromagnetic field modeling. Handling, assembly and conditioning procedures have been developed to achieve ever-increasing power levels and more reliable operation. In this paper, the technical issues associated with the design, construction, assembly, processing, and operation of FPC's will be reviewed, together with the progress in FPC activities in several laboratories during the past few years.
Date: September 1, 2001
Creator: Campisi, Isidoro E.
Partner: UNT Libraries Government Documents Department

Energy Vernier System for CEBAF

Description: The beam energy of CEBAF must be accurately controlled for precise physics experiments. In order to achieve a relative energy spread better than sigma{sub E}/E = 2.5 x 10{sup -5}, a feedback system is needed to stabilize the energy against phase and amplitude fluctuations in the individual cavities. In the energy vernier system, the energy deviation of the beam is measured at a location with high dispersion. The error signal controls the accelerating gradient of selected vernier cavities. The methods used to correct the energy will be discussed, as well as the noise sources in the system. The results of beam tests at the CEBAF north linac will also be reported.
Date: May 1, 1993
Creator: Krafft, G. A.; Bisognano, J. J.; Crofford, M. T.; Hovater, C.; Merminga, L.; Simrock, S. N. et al.
Partner: UNT Libraries Government Documents Department

Systematic approach for PID controller design for pitch-regulated, variable-speed wind turbines

Description: Variable-speed, horizontal axis wind turbines use blade-pitch control to meet specified objectives for three regions of operation. This paper focuses on controller design for the constant power production regime. A simple, rigid, non-linear turbine model was used to systematically perform trade-off studies between two performance metrics. Minimization of both the deviation of the rotor speed from the desired speed and the motion of the actuator is desired. The robust nature of the proportional-integral-derivative (PID) controller is illustrated, and optimal operating conditions are determined. Because numerous simulation runs may be completed in a short time, the relationship of the two opposing metrics is easily visualized. 2 refs., 9 figs.
Date: November 1, 1997
Creator: Hand, M.M. & Balas, M.J.
Partner: UNT Libraries Government Documents Department

Field analysis of occupancy sensor operation: Parameters affecting lighting energy savings

Description: A field study of the actual lighting savings achievable from occupancy sensor use was performed by Pacific Northwest Laboratory (PNL) for the US Department of Energy (DOE) on the Hanford Site near Richland, Washington. The study involved two seperate field assessments. The objective of the first test was to assess and effectively quantify the potential ``wasted-light`` hours associated with different occupant and space types associated with occupancy sensor control installations. These quantities are the primary factor in determining actual lighting energy savings associated with occupancy lighting control. The second test was conducted to explore the potential additional savings from more sensitive sensor equipment or better equipment adjustment that might reduce the need for delay timers. This information provides quantitative insight into the energy savings lost because of the limitations of current sensing equipment.
Date: July 1, 1995
Creator: Richman, E.E.; Dittmer, A.L. & Keller, J.M.
Partner: UNT Libraries Government Documents Department

EVALUATION OF CONSTANT CURRENT WELD CONTROL FOR PINCH WELDING

Description: Modern weld controllers typically use current to control the weld process. SRS uses a legacy voltage control method. This task was undertaken to determine if the improvements in the weld control equipment could be implemented to provide improvements to the process control. The constant current mode of operation will reduce weld variability by about a factor of 4. The constant voltage welds were slightly hotter than the constant current welds of the same nominal current. The control mode did not appear to adversely affect the weld quality, but appropriate current ranges need to be established and a qualification methodology for both welding and shunt calibrations needs to be developed and documented.
Date: October 11, 2005
Creator: Korinko, P; STANLEY, S & HOWARD, H
Partner: UNT Libraries Government Documents Department

Control-Matrix Approach to NCSX Design

Description: The control matrix approach to stellarator design yields a description of the combinations of ''control knobs'' Zj which can be adjusted to provide independent control of physics figures of merit Pi (e.g., ripple levels or kink growth rates), as well as those combinations which affect none of these Pi. This can be used both in finding superior design points, as well as in using a configuration's control knobs to have good operational flexibility about those design points. We have set up the machinery needed to perform this analysis, and here present initial results of its application to some candidate Quasi-Axisymmetric (QA) configurations. In the process of the analysis, a first exploration of the topography of the configuration space Z in the vicinity of these candidate systems has been performed, whose character is discussed.
Date: October 1, 1999
Creator: Mynick, H.E. & Pomphrey, N.
Partner: UNT Libraries Government Documents Department

Solartrak{trademark} controller developments for today`s applications

Description: The SolarTrak{trademark} array tracking controller, originally developed and licensed by Sandia National Laboratories as a low-cost, high-accuracy, reliable controller for photovoltaic (PV) concentrator arrays, has undergone significant development to make tracking accessible to a much broader segment of the PV market. Hardware and software improvements (1) reduce power consumption for PV/battery- powered applications, (2) enable the controller to connect directly with low-cost, off-the-shelf, television satellite dish actuators, (3) enable on-site setup without an additional input board, (4) increase clock accuracy by providing daily and weekly adjustments to the on board clock, and (5) include a low-cost wind stow sensor. The result is a stand-alone tracking system sufficiently low cost and reliable to make 1-kW tracking systems practical for flat plate and concentrating arrays. Results of a year of testing are presented showing clock accuracy better than a minute per year can be maintained.
Date: December 31, 1995
Creator: Maish, A.B.; O`Neill, M.; West, R. & Shugar, D.S.
Partner: UNT Libraries Government Documents Department

HEPA filter jointer

Description: A HEPA filter jointer system was created to remove nitrate contaminated wood from the wooden frames of HEPA filters that are stored at the Rocky Flats Plant. A commercial jointer was chosen to remove the nitrated wood. The chips from the wood removal process are in the right form for caustic washing. The jointer was automated for safety and ease of operation. The HEPA filters are prepared for jointing by countersinking the nails with a modified air hammer. The equipment, computer program, and tests are described in this report.
Date: February 1, 1998
Creator: Hill, D. & Martinez, H.E.
Partner: UNT Libraries Government Documents Department

Distributed Sensing and Cooperating Control for Swarms of Robotic vehicles

Description: DISTRIBUTED SENSING AND COOPERATING CONTROL FOR SWARMS OF ROBOTIC VEHICLES Key words: Distributed Sensing, Cooperative Control. ABSTRACT We discuss an approach to effectively control a large swarm of autonomous, robotic vehicles, as they per- form a search and tag operation. In particular, the robotic agents are to find the source of a chemical plume. The robotic agents work together through dis- tributed sensing and cooperative control. Distributed sensing is achieved through each agent sampling and sharing his information with others. Cooperative con- trol h accomplished by each agent u-sing its neighbors information to determine an update strategy. INTRODUCTION There is currently considerable interest in expanding the role of robotic vehicles in surveillance and inspec- tion; searching, following and t aggir-g and locating and identifying targets. In particular, researchers are beginning to focus on using small autonomous robotic vehicles for these tasks. This focus has been brought about largely because of the many recent advances in microelectronics and sensors, which include small, low power, CCD cameras; small microprocessors with ex- panded capabilities; autonomous navigation systems using GPS; and severrd types of small sensors. It seems likely that these technological advances will lead to in- expensive, easy to fabricate, autonomous vehicles out- fitted with an array of sensors. This, in turn, will allow researchers to consider teams, or even swarms, of these agents to perform a particular task. It is natural then to wonder how one might effectively control a team, or even a swarm, of robotic agents. In this paper, we discuss an approach to effectively control a large swarm of autonomous, robotic vehicles as they perform a search and tag operation. In par- ticular, the robotic agents are to find the source of a chemical plume. The robotic agents work together through distributed sensing and cooperative control. Distributed sensing is ...
Date: October 9, 1998
Creator: Dohrmann, C. R.; Goldsmith, S. Y.; Hurtado, J. E. & Robinett, R. D.
Partner: UNT Libraries Government Documents Department

Multiple Shaker Random Vibration Control--An Update

Description: The theory of the control of multiple shakers driving a single test item is reviewed. Several improvements that have been introduced since the original papers on the subject will be discussed. The improvements include: (1) specification of the control spectra; (2) the control of non-square systems (the number of shakers does not have to be equal to the number of control points); (3) the connection between sine testing, waveform control, and random control; (4) improvements in feedback control; (5) overlap-add versus time domain randomization; and (6) reproduction of non-Gaussian waveforms.
Date: February 18, 1999
Creator: Smallwood, D.O.
Partner: UNT Libraries Government Documents Department

Disturbance Rejection Control of an Electromagnetic Bearing Spindle

Description: The force exerted on the rotor by an active magnetic bearing (AMB) is determined by the current flow in the magnet coils. This force can be controlled very precisely, making magnetic bearings a potential benefit for grinding, where cutting forces act as external disturbances on the shaft, resulting in degraded part finish. It is possible to achieve precise shaft positioning, reduce vibration of the shaft caused by external disturbances, and even damp out resonant modes. Adaptive control is an appealing approach for these systems because the controller can tune itself to account for an unknown periodic disturbance, such as cutting or grinding forces, injected into the system. In this paper the authors show how one adaptive control algorithm can be applied to an AMB system with a periodic disturbance applied to the rotor. An adaptive algorithm was developed and implemented in both simulation and hardware, yielding significant reductions in rotor displacement in the presence of an external excitation. Ultimately, this type of algorithm could be applied to a magnetic bearing grinder to reduce unwanted motion of the spindle which leads to poor part finish and chatter.
Date: August 31, 2000
Creator: PETTEYS,REBECCA & PARKER,GORDON
Partner: UNT Libraries Government Documents Department

ELECTRONICS UPGRADE OF HIGH RESOLUTION MASS SPECTROMETERS

Description: High resolution mass spectrometers are specialized systems that allow researchers to determine the exact mass of samples to four significant digits by using magnetic and electronic sector mass analyzers. Many of the systems in use today at research laboratories and universities were designed and built more than two decades ago. The manufacturers of these systems have abandoned the support for some of the mass spectrometers and parts to power and control them have become scarce or obsolete. The Savannah River National Laboratory has been involved in the upgrade of the electronics and software for these legacy machines. The Electronics Upgrade of High Resolution Mass Spectrometers consists of assembling high-end commercial instrumentation from reputable manufacturers with a minimal amount of customization to replace the electronics for the older systems. By taking advantage of advances in instrumentation, precise magnet control can be achieved using high resolution current sources and continuous feedback from a high resolution hall-effect probe. The custom equipment include a precision voltage divider/summing amplifier chassis, high voltage power supply chassis and a chassis for controlling the voltage emission for the mass spectrometer source tube. The upgrade package is versatile enough to interface with valve control, vacuum and other instrumentation. Instrument communication is via a combination of Ethernet and traditional IEEE-488 GPIB protocols. The system software upgrades include precision control, feedback and spectral waveform analysis tools.
Date: March 10, 2008
Creator: Mcintosh, J & Joe Cordaro, J
Partner: UNT Libraries Government Documents Department

A switched state feedback law for the stabilization of LTI systems.

Description: Inspired by prior work in the design of switched feedback controllers for second order systems, we develop a switched state feedback control law for the stabilization of LTI systems of arbitrary dimension. The control law operates by switching between two static gain vectors in such a way that the state trajectory is driven onto a stable n - 1 dimensional hyperplane (where n represents the system dimension). We begin by briefly examining relevant geometric properties of the phase portraits in the case of two-dimensional systems to develop intuition, and we then show how these geometric properties can be expressed as algebraic constraints on the switched vector fields that are applicable to LTI systems of arbitrary dimension. We then derive necessary and sufficient conditions to ensure stabilizability of the resulting switched system (characterized primarily by simple conditions on eigenvalues), and describe an explicit procedure for designing stabilizing controllers. We then show how the newly developed control law can be applied to the problem of minimizing the maximal Lyapunov exponent of the corresponding closed-loop state trajectories, and we illustrate the closed-loop transient performance of these switched state feedback controllers via multiple examples.
Date: September 1, 2009
Creator: Santarelli, Keith R.
Partner: UNT Libraries Government Documents Department