Application of switching theory to control systems
Switching theory application to control systems
SET THEORY↗
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Results for “System control”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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The automation of an inlet mass flow control system
The automation of a closed-loop computer controlled system for the inlet mass flow system (IMFS) developed for a wind tunnel facility at Langley Research Center is presented. This new PC based control system is intended to replace the manual control system presently in use in order to fully automate the plug positioning of the IMFS during wind tunnel testing. Provision is also made for communication between the PC and a host-computer in order to allow total animation of the plug positioning and data acquisition during the complete sequence of predetermined plug locations. As extensive running time is programmed for the IMFS, this new automated system will save both manpower and tunnel running time.
Supplee, Frank↗
Apollo experience report: Lunar module reaction control system
The design, development and qualification of the reaction control system for the Apollo lunar module are described. The lunar module reaction control system used many of the components developed and qualified for the service module reaction control system. The system was qualified for manned flight during the unmanned Apollo 5 mission on January 22 and 23, 1968, and has operated satisfactorily during all manned lunar module flights including Apollo 11, the first manned landing on the moon.
Vaughan, C. A.↗
The control of satellites with microgravity constraints: The COMET Control System
The COMET attitude determination and control system, using inverse dynamics and a novel torque distribution/momentum management technique, has shown great flexibility, performance, and robustness. Three-axis control with two wheels is an inherent consequence of inverse dynamics control which allows for reduction in spacecraft weight and cost, or alternatively, provides a simple means of failure-redundancy for three-wheel spacecraft. The control system, without modification, has continued to perform well in spite of large changes in spacecraft mass properties and mission orbit altitude that have occurred during development. This flexibility has obviated imposition of early stringent ADACS design constraints and has greatly reduced commonly incurred ADACS modification costs and delay associated with program maturation.
Grossman, Walter↗
Integrated digital flight-control system for the space shuttle orbiter
The integrated digital flight control system is presented which provides rotational and translational control of the space shuttle orbiter in all phases of flight: from launch ascent through orbit to entry and touchdown, and during powered horizontal flights. The program provides a versatile control system structure while maintaining uniform communications with other programs, sensors, and control effectors by using an executive routine/functional subroutine format. The program reads all external variables at a single point, copies them into its dedicated storage, and then calls the required subroutines in the proper sequence. As a result, the flight control program is largely independent of other programs in the GN&C computer complex and is equally insensitive to the characteristics of the processor configuration. The integrated structure of the control system and the DFCS executive routine which embodies that structure are described along with the input and output. The specific estimation and control algorithms used in the various mission phases are given.
Source record↗
Digital-twin-based improvements to diagnosis, prognosis, strategy assessment, and discrepancy checking in a nearly autonomous management and control system
We report the Nearly Autonomous Management And Control System (NAMAC) is a comprehensive control system to assist plant operations by furnishing control recommendations to operators in a broad class of situations. This study refines a NAMAC system for making reasonable recommendations during complex loss of flow (LOF) scenarios with a validated EBR-II simulator, digital twins improved by machine-learning algorithms, a multi-attribute decision-making scheme, and a discrepancy checker for identifying unexpected recommendation effects. The performance of each NAMAC component is assessed, while the capability of NAMAC is demonstrated and evaluated in a class of LOF scenarios.
22 GENERAL STUDIES OF NUCLEAR REACTORS↗
Root Cause Assessment of Pressure Drop Rise of a Packed Bed of Lithium Hydroxide in the International Space Station Trace Contaminant Control System
The trace contaminant control system (TCCS) located in the International Space Station s (ISS) U.S. laboratory module employs physical adsorption, thermal catalytic oxidation, and chemical adsorption to remove trace chemical contamination produced by equipment offgassing and anthropogenic sources from the cabin atmosphere. The chemical adsorption stage, consisting of a packed bed of granular lithium hydroxide (LiOH), is located after the thermal catalytic oxidation stage and is designed to remove acid gas byproducts that may be formed in the upstream oxidation stage. While in service on board the ISS, the LiOH bed exhibited a change in flow resistance that leading to flow control difficulties in the TCCS. Post flight evaluation revealed LiOH granule size attrition among other changes. An experimental program was employed to investigate mechanisms hypothesized to contribute to the change in the packed bed s flow resistance. Background on the problem is summarized, including a discussion of likely mechanisms. The experimental program is described, results are presented, and implications for the future are discussed.
Aguilera, Tatiana↗
System Applications Software Development and Testing for the Spaceport Command and Control System
Known as "America's Spaceport," one of Kennedy Space Center's (KSC) primary responsibilities is the successful preparation for and launch of rockets into space. KSC's Engineering Software Branch has been tasked with creating a new command and control system that will provide check-out and launch control for future rockets and spacecraft. While work on the software began several years ago, development is ongoing and the operators who use the software on a daily basis have requested several features to improve their user experience. My internship in the fall of 2018 involved developing the source code and unit tests for two of these requested features: "Display Data with Persistence" (DDP) and "Save Events Button" (SEB). DDP's primary goal is to aid with ergonomics. Currently, users must press-and-hold on the mouse button to display information about points on a data plot. Once DDP is integrated, users will have the ability to double-click on a data plot to display that same information with persistence. Independent from DDP, the SEB provides users the ability to take information about different events that occur in the control system and save that data into a simple Comma Separated File (.csv) file format for easier analysis at a future time.
Niemoeller, Samantha↗
Simulator evaluation of a flight-path-angle control system for a transport airplane with direct lift control
A piloted simulator was used to evaluate the flight path angle control capabilities of a system that employs spoiler direct lift control. The system was designated the velocity vector control system and was compared with a baseline flight path angle control system which used elevator for control. The simulated airplane was a medium jet transport. Research pilots flew a manual instrument landing system glide slope tracking task and a variable flight path angle task in the landing configuration to obtain comparative performance data.
Kelley, W. W.↗
Development and Flight Test of an Augmented Thrust-Only Flight Control System on an MD-11 Transport Airplane
An emergency flight control system using only engine thrust, called Propulsion-Controlled Aircraft (PCA), has been developed and flight tested on an MD-11 airplane. In this thrust-only control system, pilot flight path and track commands and aircraft feedback parameters are used to control the throttles. The PCA system was installed on the MD-11 airplane using software modifications to existing computers. Flight test results show that the PCA system can be used to fly to an airport and safely land a transport airplane with an inoperative flight control system. In up-and-away operation, the PCA system served as an acceptable autopilot capable of extended flight over a range of speeds and altitudes. The PCA approaches, go-arounds, and three landings without the use of any non-nal flight controls have been demonstrated, including instrument landing system-coupled hands-off landings. The PCA operation was used to recover from an upset condition. In addition, PCA was tested at altitude with all three hydraulic systems turned off. This paper reviews the principles of throttles-only flight control; describes the MD-11 airplane and systems; and discusses PCA system development, operation, flight testing, and pilot comments.
Burcham, Frank W., Jr.↗
Integrated High-Speed Torque Control System for a Robotic Joint
A control system for achieving high-speed torque for a joint of a robot includes a printed circuit board assembly (PCBA) having a collocated joint processor and high-speed communication bus. The PCBA may also include a power inverter module (PIM) and local sensor conditioning electronics (SCE) for processing sensor data from one or more motor position sensors. Torque control of a motor of the joint is provided via the PCBA as a high-speed torque loop. Each joint processor may be embedded within or collocated with the robotic joint being controlled. Collocation of the joint processor, PIM, and high-speed bus may increase noise immunity of the control system, and the localized processing of sensor data from the joint motor at the joint level may minimize bus cabling to and from each control node. The joint processor may include a field programmable gate array (FPGA).
Davis, Donald R.↗
ADROC: An Emulation Experimentation Platform for Advancing Resilience of Control Systems
Cyberattacks against industrial control systems have increased over the last decade, making it more critical than ever for system owners to have the tools necessary to understand the cyber resilience of their systems. However, existing tools are often qualitative, subject matter expertise-driven, or highly generic, making thorough, data-driven cyber resilience analysis challenging. The ADROC project proposed to develop a platform to enable efficient, repeatable, data-driven cyber resilience analysis for cyber-physical systems. The approach consists of two phases of modeling: computationally efficient math modeling and high-fidelity emulations. The first phase allows for scenarios of low concern to be quickly filtered out, conserving resources available for analysis. The second phase supports more detailed scenario analysis, which is more predictive of real-world systems. Data extracted from experiments is used to calculate cyber resilience metrics. ADROC then ranks scenarios based on these metrics, enabling prioritization of system resources to improve cyber resilience.
97 MATHEMATICS AND COMPUTING↗
Reduction of control system design effort
Reliable control systems with satisfactory dynamic response for launch vehicles
Redus, J. R.↗
A discussion of the stability requirements for a launch vehicle flight control system
Launch vehicle flight control system and relation to stability requirements and dynamic responses
Redus, J. R.↗
Decoupling in the design and synthesis of multivariable control systems.
Time invariant linear control system decoupling using state variable feedback, determining synthesis procedure to obtain desired closed loop configurations
Falb, P. L.↗
Design and application of an adaptive tracking filter control system.
Adaptive tracking filter control system design and application to large flexible booster vehicles
Dupont, T. E.↗
A subliming solid reaction control system.
Subliming solid reaction control system design, operation and test for ATS
Routt, R. P.↗
Quasi-optimum design of an aircraft landing control system.
Quasi-optimum control law for aircraft landing control system design based on Friedland technique, evaluating effectiveness by computer simulation
Ling, C. K.↗