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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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This document is the final technical report for the UC Davis project DE-SC00023500, detailing the development and implementation of a Fast Recurrent Neural Network (FRNN) software. The software was designed to enable predictive, real-time control of plasma instabilities within the DIII-D Plasma Control System (PCS).
Wind turbines are complex, nonlinear, dynamic systems driven by aerodynamic, gravitational, centrifugal, and gyroscopic forces. The aerodynamics of wind turbines are nonlinear, unsteady, and complex. Turbine rotors are subjected to a chaotic three-dimensional (3-D) turbulent wind inflow field with imbedded coherent vortices that drive fatigue loads and reduce lifetime. In order to reduce cost of energy, future large multimegawatt turbines must be designed with lighter weight structures, using active controls to mitigate fatigue loads, maximize energy capture, and add active damping to maintain stability for these dynamically active structures operating in a complex environment. Researchers at the National Renewable Energy Laboratory (NREL) and University of Stuttgart are designing, implementing, and testing advanced feed-back and feed-forward controls in order to reduce the cost of energy for wind turbines.
To expand the functional capabilities of industrial controllers for systems subject to external disturbances, developments to date are reviewed, and an approach permitting the generation of control signals on the basis of predictions is proposed and tested. The benefits of this approach are assessed. It is best used for large industrial equipment and systems in manufacturing and the oil and gas industry.
Control trailing-edge thickness and aspect ratio effect on oscillating hinge-moment and flutter characteristics of flap-type controls
Capability of lateral control system to provide aerodynamic heading-angle control of vehicle having maximum lift-drag ratio during reentry
Motion stabilization of controlled member in control system with time delay
Application and extension of modern automatic control theory to nuclear rocket dynamics and control
Liapunov method for closed loop time optimal control of linear systems with bounded control norm using eigenvector scalar product solution for Hamilton-Jacobi equation
Charge-current control circuit for nickel-cadmium cells with control electrodes
Digital controller using multirate sampling for gain control
Manual gain control remote-control subsystem for Mars deep space station radar receiver
Charge current control circuit for nickel- cadmium cells with control electrodes
Studies in optimal behavior in manual control systems - effect of four performance criteria in compensatory rate-control tracking
Low solar absorption surface coatings of aluminum, silver and silica with controlled emittance for spacecraft thermal control
Model accounting for adaptation of well-trained human controller to sudden changes in controlled process dynamics of compensatory tracking system
This paper provides a comprehensive survey of spacecraft formation flying control, which encompasses design techniques and stability results for these coupled-state control laws.
Two-phase thermal control systems in microgravity, with significant density differences between phases, pose challenges for many current and proposed spacecraft systems. Because of the lack of understanding of these effects and the inability to scale multiphase systems in low gravity, NASA generally opts to avoid using two-phase systems for spacecraft despite the significant performance increases and lower mass. The goal of this panel discussion will be to identify key technology gaps and challenges that thermal engineers face today when considering a two-phase thermal management system. The panel discussion will begin with a brief overview of recent and on-going NASA projects designed to elicit a fundamental understanding of gas-liquid two phase behavior as it applies to thermal control systems in the Space environment. The projects/experiments discussed will range from boiling/condensation fundamentals, heat pipes, and cryogenic storage systems. We will identify what fundamental question or questions are being addressed in each case. An overview will be also be presented to address future mission needs and the specific advantages multi-phase systems offer, in particular for low cost planetary science missions and enabling missions in extreme environments. The need for efficient heat transfer with concurrent spatial and temporal temperature stability to reduce thermally-induced noise drives a serious look at multi-phase systems as a solution. Furthermore, missions to environments such as the Venus surface or penetration of ice layers in ocean worlds will likely require them. Time will be allocated at the end of this session to allow comments and questions from attendees. The intent is to use this session as a starting point to advocate for a coordinated technology development effort in this area.
Configurable Control Rooms provide the ability to rapidly change capabilities from mission to mission and customer to customer. Future missions will likely not have the 24/7/365 need for a dedicated mission support room, and CCR could easily be adapted for continuous support if needed. CCRs offer physical, centralized locations for teams to support, and the HOSC provides a secure, reliable facility with constant monitoring by network specialists. Institutions and payload teams can cost save by utilizing a CCR at MSFC eliminating the need to assemble an entire custom control room at their location. This new paradigm in flight operations can ease the creation of any mission from a cubesat to a New Frontiers or Flagship program and anything in between.