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Analytical determination of control system pulley-axis angles

Description: From Introduction: "The ideas developed in this paper are presented as a means of saving the designer's time and as a method of reduction of control-system friction by an accurate calculation of pulley-axis angles without the errors and difficult checking incident to any graphical method."
Date: September 1941
Creator: Driggs, H I
Partner: UNT Libraries Government Documents Department

Performance of Powerline-Controlled Luminaire Final Report

Description: In previous work, LBNL with Vistron Corp, developed an innovative lighting control system using a communications technology called Phase Cut Carrier (PCC). This report describes the performance of the desktop demonstration system that was developed to test this new controls concept. More detailed information on this project is given in [1]. This report is in fulfillment of deliverable No.1 'Report on Performance of Powerline-carrier Controlled Luminaire' from the FY2004 DOE Work Plan.
Date: December 1, 2004
Creator: Rubinstein, Francis; Pettler, Pete; Snook, Joel; Engelking, Erik & Kiliccote, Sila
Partner: UNT Libraries Government Documents Department

Investigation of a nonlinear control system

Description: A discontinuous variation of coefficients of the differential equation describing the linear control system before nonlinear elements are added is studied in detail. The nonlinear feedback is applied to a second-order system. Simulation techniques are used to study performance of the nonlinear control system and to compare it with the linear system for a wide variety of inputs. A detailed quantitative study of the influence of relay delays and of a transport delay is presented.
Date: October 18, 1957
Creator: Flügge-Lotz, I.; Taylor, C. F. & Lindberg, H. E.
Partner: UNT Libraries Government Documents Department

Investigation of a nonlinear control system

Description: A discontinuous variation of coefficients of the differential equation describing the linear control system before nonlinear elements are added is studied in detail. The nonlinear feedback is applied to a second-order system. Simulation techniques are used to study performance of the nonlinear control system and to compare it with the linear system for a wide variety of inputs. A detailed quantitative study of the influence of relay delays and of a transport delay is presented.
Date: April 1957
Creator: Flügge-Lotz, I. & Taylor, C. F.
Partner: UNT Libraries Government Documents Department

Flight investigation of factors affecting pilots' ability to utilize a radarscope display of steering information

Description: Report presenting results of a flight investigation of a radar fire-control system installed in a fighter airplane. Some of the factors included in the radar evaluation are "noise" of the steering dot, lack of target-attitude information, and sensitivity and linearity of the display.
Date: November 23, 1956
Creator: Faber, Stanley; Cheatham, Donald C. & Champine, Robert A.
Partner: UNT Libraries Government Documents Department

Flight investigation of a roll-stabilized ramjet test vehicle over a Mach number range of 2.3 to 2.7

Description: Report presenting a flight investigation on a roll-stabilized ramjet test vehicle to determine engine performance over a range of Mach numbers, a range of fuel-air ratio, and an altitude range. Results regarding engine performance and roll autopilot performance are provided.
Date: October 7, 1955
Creator: Kennedy, Thomas L. & Trout, Otto F., Jr.
Partner: UNT Libraries Government Documents Department

Empirical Estimates of 0Day Vulnerabilities in Control Systems

Description: We define a 0Day vulnerability to be any vulnerability, in deployed software, which has been discovered by at least one person but has not yet been publicly announced or patched. These 0Day vulnerabilities are of particular interest when assessing the risk to well managed control systems which have already effectively mitigated the publicly known vulnerabilities. In these well managed systems the risk contribution from 0Days will have proportionally increased. To aid understanding of how great a risk 0Days may pose to control systems, an estimate of how many are in existence is needed. Consequently, using the 0Day definition given above, we developed and applied a method for estimating how many 0Day vulnerabilities are in existence on any given day. The estimate is made by: empirically characterizing the distribution of the lifespans, measured in days, of 0Day vulnerabilities; determining the number of vulnerabilities publicly announced each day; and applying a novel method for estimating the number of 0Day vulnerabilities in existence on any given day using the number of vulnerabilities publicly announced each day and the previously derived distribution of 0Day lifespans. The method was first applied to a general set of software applications by analyzing the 0Day lifespans of 491 software vulnerabilities and using the daily rate of vulnerability announcements in the National Vulnerability Database. This led to a conservative estimate that in the worst year there were, on average, 2500 0Day software related vulnerabilities in existence on any given day. Using a smaller but intriguing set of 15 0Day software vulnerability lifespans representing the actual time from discovery to public disclosure, we then made a more aggressive estimate. In this case, we estimated that in the worst year there were, on average, 4500 0Day software vulnerabilities in existence on any given day. We then proceeded to identify the subset ...
Date: January 1, 2009
Creator: McQueen, Miles A.; Boyer, Wayne F.; McBride, Sean M. & McQueen, Trevor A.
Partner: UNT Libraries Government Documents Department

Deception used for Cyber Defense of Control Systems

Description: Control system cyber security defense mechanisms may employ deception to make it more difficult for attackers to plan and execute successful attacks. These deceptive defense mechanisms are organized and initially explored according to a specific deception taxonomy and the seven abstract dimensions of security previously proposed as a framework for the cyber security of control systems.
Date: May 1, 2009
Creator: Boyer, Wayne F. & McQueen, Miles A.
Partner: UNT Libraries Government Documents Department

PC/104 Embedded IOCs at Jefferson Lab

Description: Jefferson Lab has developed embedded IOCs based on PC/104 single board computers (SBC) for low level control systems. The PC/104 IOCs run EPICS on top of the RTEMS operating system. Two types of control system configurations are used in different applications, PC/104 SBC with commercial PC/104 I/O cards and PC/104 SBC with custom designed FPGA-based boards. RTEMS was built with CEXP shell to run on the PC/104 SBC. CEXP shell provides the function of dynamic object loading, which is similar to the widely used VxWorks operating system. Standard software configurations were setup for PC/104 IOC application development to provide a familiar format for new projects as well as ease the conversion of applications from VME based IOCs to PC/104 IOCs. Many new projects at Jefferson Lab are going to employ PC/104 SBCs as IOCs and some applications have already been running them for accelerator operations. The PC/104 - RTEMS IOC provides a free open source Real-Time Operating System (RTOS), low cost/maintenance, easily installed/ configured, flexible, and reliable solution for accelerator control and 12GeV Upgrade projects.
Date: October 1, 2009
Creator: Jianxun Yan, Trent Allison, Sue Witherspoon, Anthony Cuffe
Partner: UNT Libraries Government Documents Department

Design and Implementation of an Open, Interoperable AutomatedDemand Response Infrastructure

Description: This paper describes the concept for and lessons from the development and field-testing of an open, interoperable communications infrastructure to support automating demand response (DR). Automating DR allows greater levels of participation and improved reliability and repeatability of the demand response and customer facilities. Automated DR systems have been deployed for critical peak pricing and demand bidding and are being designed for real time pricing. The system is designed to generate, manage, and track DR signals between utilities and Independent System Operators (ISOs) to aggregators and end-use customers and their control systems.
Date: October 1, 2007
Creator: Piette, Mary Ann; Kiliccote, Sila & Ghatikar, Girish
Partner: UNT Libraries Government Documents Department

Free-flight-tunnel tests of a target-seeking glide-bomb model with flicker lateral control

Description: Report presenting an investigation of control systems suitable for target-seeking missiles. Testing occurred in the free-flight tunnel of the GB-5 glide bomb equipped with a light-seeker control unit which applied flicker control. Results indicated that good stability could be obtained with the control system, but was somewhat less stable than with a proportional control system.
Date: July 28, 1948
Creator: McKinney, Marion O., Jr. & Drake, Hubert M.
Partner: UNT Libraries Government Documents Department

W-026 acceptance test report plant control system hardware (submittal {number_sign} 220.C)

Description: Acceptance Testing of the WRAP1 Plant Control System Hardware was conducted throughout the construction of WRAPI with the final testing on the Process Area hardware being completed in November 1996. The hardware tests were broken out by the following functional areas; Local Control Units, Operator Control Stations in the WRAP Control Room, DMS Server, PCS Server, Operator Interface Units, printers, DMS terminals, WRAP Local Area Network/Communications, and bar code equipment. This document contains a completed copy of each of the hardware tests along with the applicable test logs and completed test exception reports.
Date: February 14, 1997
Creator: Watson, T.L., Fluor Daniel Hanford
Partner: UNT Libraries Government Documents Department

Device control at CEBAF

Description: CEBAF has undergone a major conversion of its accelerator control system from TACL to EPICS, affecting device control for the RF system, magnets, the machine protection system, the vacuum and valves, and the diagnostic systems including beam position monitors, harps, and the camera and solenoid devices (beam viewers, faraday cups, optical transition radiation viewers, synchrotron radiation monitor, etc.). Altogether these devices require approximately 125,000 EPICS database records. The majority of these devices are controlled through CAMAC; some use embedded microprocessors (RF and magnets), and newer interfaces are in VME. The standard EPICS toolkit was extended to include a driver for CAMAC which supports dual processors on one serial highway, custom database records for magnets and BPMs, and custom data acquisition tasks for the BPMs. 2 refs., 1 tab.
Date: August 1, 1996
Creator: Schaffner, S.; Barker, D. & Bookwalter, V.
Partner: UNT Libraries Government Documents Department

A flight investigation of the handling characteristics of a fighter airplane controlled through a rate type of automatic control system

Description: Report presenting an investigation of the handling qualities of a fighter airplane that is controlled by a pilot supplying signals to a rate type of automatic control system. The handling qualities were investigated in pull-ups, aileron rolls, aerobatics, rough-air flying, and precision tasks.
Date: September 14, 1956
Creator: Russell, Walter R.; Sjoberg, S. A. & Alford, William L.
Partner: UNT Libraries Government Documents Department

Experimental investigation of a surge control on a turbojet engine

Description: The action of a surge control that reduced fuel flow after receiving an indication of surge initiation was investigated. The control system could successfully limit surge to only 1 cycle but could not completely eliminate surge. Inability to interrupt a surge cycle before its completion was attributed to the conclusion that a surge cycle is irreversible.
Date: November 18, 1955
Creator: Novik, David; Heppler, Herbert & Stiglic, Paul M.
Partner: UNT Libraries Government Documents Department

Theoretical study of some methods for increasing the smoothness of flight through rough air

Description: Report presenting a theoretical study of the response to gusts and stability and control characteristics of an airplane equipped with systems in which wing flaps and elevators are operated to reduce accelerations in rough air. The surfaces are actuated by an automatic control system in response to indications of an angle-of-attack vane or accelerometer.
Date: July 1951
Creator: Phillips, William H. & Kraft, Christopher C., Jr.
Partner: UNT Libraries Government Documents Department

A theoretical investigation of longitudinal stability of airplanes with free controls including effect of friction in control system

Description: From Summary: "The relation between the elevator hinge-moment parameters and the control forces for changes in forward speed and in maneuvers is shown for several values of static stability and elevator mass balance." Factors affecting stability positively and negatively are presented and potential modifications to the elevator control system are provided. The amount of solid friction present was found to be one of the greatest predictors of instability.
Date: February 1944
Creator: Greenberg, Harry & Sternfield, Leonard
Partner: UNT Libraries Government Documents Department

Next generation epics interface to abstract data.

Description: The set of externally visible properties associated with process variables in the Experimental Physics and Industrial Control System (EPICS) is predefined in the EPICS base distribution and is therefore not extensible by plug-compatible applications. We believe that this approach, while practical for early versions of the system with a smaller user base, is now severely limiting expansion of the high-level application tool set for EPICS. To eliminate existing barriers, we propose a new C++ based interface to abstract containerized data. This paper describes the new interface, its application to message passing in distributed systems, its application to direct communication between tightly coupled programs co-resident in an address space, and its paramount position in an emerging role for EPICS -- the integration of dissimilar systems.
Date: January 1, 2001
Creator: Hill, J. O. (Jeffrey O.) & Lange, R. (Ralph)
Partner: UNT Libraries Government Documents Department