Results for “shared control” — Page 31

NASA NTRS2001

Distributed Spacecraft Control Architectures

A fundamental issue for estimation and control of distributed systems such as formation flying spacecraft is the information exchange architecture. In centralized schemes, each subordinate need only share its measurement data with a central hub, and the subordinates depend on the center to direct their actions. In decentralized schemes, all nodes participate in the data exchange, so that each has the same in by formation as the center, and may thereby self-direct the same action that the center would have commanded, assuming all share a common goal. This talk compares and contrasts the centralized and decentralized schemes in the context of autonomously maintaining a distributed satellite formation.

Carpenter, James Russell↗

NASA NTRS2019

Neural Network Based Optimal Control: Resilience to Missed Thrust Events for Long Duration Transfers

A growing number of spacecraft are continuing to adopt new and more efficient forms of in-space propulsion. One shared characteristic of these high-efficiency propulsion techniques is their limited thrust capabilities. This requires them to thrust continuously for long periods of time, making the spacecraft susceptible to potential missed thrust events. This work demonstrates how neural networks can autonomously correct for missed thrust events during a low-thrust long-duration transfer trajectory. The research applies and tests the developed method to au- tonomously correct a Mars return trajectory. Additionally, methods for improving the response of neural networks to missed thrust events are presented and further investigated.

Laipert, Frank E.↗

DOE OSTI2024

An Innovative Energy Management System for Microgrids with Multiple Grid-Forming Inverters

As increasingly more grid-forming (GFM) inverter-based resources replace traditional fossil-fueled synchronous generators as the GFM sources in microgrids, the existing microgrid energy management systems (EMS) need to be updated to control and coordinate multiple GFM inverters that consider system control objectives under different microgrid connection states.For each state, we formulate an optimization problem and apply a real-time feedback-based control algorithm; altogether, the control algorithms seamlessly connect the states into a generic microgrid EMS that controls the nodal voltages and frequencies, becomes a virtual power plant (VPP) when connected to the main grid, and coordinates power sharing responsibility among GFM sources when islanded. We showcase the EMS on a real-world simulation of a microgrid under the different states to demonstrate its operational effectiveness.

energy management system↗

NASA NTRS2005

Support for User Interfaces for Distributed Systems

An extensible Java(TradeMark) software framework supports the construction and operation of graphical user interfaces (GUIs) for distributed computing systems typified by ground control systems that send commands to, and receive telemetric data from, spacecraft. Heretofore, such GUIs have been custom built for each new system at considerable expense. In contrast, the present framework affords generic capabilities that can be shared by different distributed systems. Dynamic class loading, reflection, and other run-time capabilities of the Java language and JavaBeans component architecture enable the creation of a GUI for each new distributed computing system with a minimum of custom effort. By use of this framework, GUI components in control panels and menus can send commands to a particular distributed system with a minimum of system-specific code. The framework receives, decodes, processes, and displays telemetry data; custom telemetry data handling can be added for a particular system. The framework supports saving and later restoration of users configurations of control panels and telemetry displays with a minimum of effort in writing system-specific code. GUIs constructed within this framework can be deployed in any operating system with a Java run-time environment, without recompilation or code changes.

Eychaner, Glenn↗

NASA NTRS2002

The Microwave Anisotropy Probe (MAP) Guidance, Navigation, and Control Hardware Suite

The on-orbit success of the Microwave Anisotropy Probe (MAP) Guidance, Navigation, and Control System can partially be attributed to the performance of a hardware suite chosen to meet the complex attitude determination and control requirements of the mission. To meet these requirements, a diverse set of components was used. The set included two Lockheed Martin AST-201 star trackers, two Kearfott Two-Axis Rate Assemblies mounted to provide X, Y and redundant Z-axis rates, two Adcole Digital Sun Sensor heads sharing one set of electronics, twelve Adcole Coarse Sun Sensor eyes, three Ithaco E-sized Reaction Wheel Assemblies, a Propulsion Subsystem that employed eight Primex Rocket Engine Modules, and a pair of Goddard-designed Attitude Control Electronics which connect all of the components to the spacecraft processor. The performance of this hardware is documented, as are some of the spacecraft accommodations and lessons learned that came from working with this particular set of hardware.

Ward, David K.↗

NASA NTRS1995

Langley's CSI evolutionary model: Phase 2

Phase 2 testbed is part of a sequence of laboratory models, developed at NASA Langley Research Center, to enhance our understanding on how to model, control, and design structures for space applications. A key problem with structures that must perform in space is the appearance of unwanted vibrations during operations. Instruments, design independently by different scientists, must share the same vehicle causing them to interact with each other. Once in space, these problems are difficult to correct and therefore, prediction via analysis design, and experiments is very important. Phase 2 laboratory model and its predecessors are designed to fill a gap between theory and practice and to aid in understanding important aspects in modeling, sensor and actuator technology, ground testing techniques, and control design issues. This document provides detailed information on the truss structure and its main components, control computer architecture, and structural models generated along with corresponding experimental results.

Horta, Lucas G.↗

NASA NTRS2007

Control of Dual-Opposed Stirling Convertors with Active Power Factor Correction Controllers

When using recently-developed active power factor correction (APFC) controllers in power systems comprised of dual-opposed free-piston Stirling convertors, a variety of configurations of the convertors and controller(s) can be considered, with configuration ultimately selected based on benefits of efficiency, reliability, and robust operation. The configuration must not only achieve stable control of the two convertors, but also synchronize and regulate motion of the pistons to minimize net dynamic forces. The NASA Glenn Research Center (GRC) System Dynamic Model (SDM) was used to study ten configurations of dual-opposed convertor systems. These configurations considered one controller with the alternators connected in series or in parallel, and two controllers with the alternators not connected (isolated). For the configurations where the alternators were not connected, several different approaches were evaluated to synchronize the two convertors. In addition, two thermodynamic configurations were considered: two convertors with isolated working spaces and convertors with a shared expansion space. Of the ten configurations studied, stable operating modes were found for four. Three of those four had a common expansion space. One stable configuration was found for the dual-opposed convertors with separate working spaces. That configuration required isochronous control of both convertors, and two APFC controllers were used to accomplish this. A frequency/phase control loop was necessary to allow each APFC controller to synchronize its associated convertor with a common frequency.

Regan, Timothy F.↗

NASA NTRS2006

Control of Dual-Opposed Stirling Convertors with Active Power Factor Correction Controllers

When using recently-developed active power factor correction (APFC) controllers in power systems comprised of dual-opposed free-piston Stirling convertors, a variety of configurations of the convertors and controller(s) can be considered, with configuration ultimately selected based on benefits of efficiency, reliability, and robust operation. The configuration must not only achieve stable control of the two convertors, but also synchronize and regulate motion of the pistons to minimize net dynamic forces. The NASA Glenn Research Center (GRC) System Dynamic Model (SDM) was used to study ten configurations of dual-opposed convertor systems. These configurations considered one controller with the alternators connected in series or in parallel, and two controllers with the alternators not connected (isolated). For the configurations where the alternators were not connected, several different approaches were evaluated to synchronize the two convertors. In addition, two thermodynamic configurations were considered: two convertors with isolated working spaces and convertors with a shared expansion space. Of the ten configurations studied, stable operating modes were found for four. Three of those four had a common expansion space. One stable configuration was found for the dual-opposed convertors with separate working spaces. That configuration required isochronous control of both convertors, and two APFC controllers were used to accomplish this. A frequency/phase control loop was necessary to allow each APFC controller to synchronize its associated convertor with a common frequency.

Regan, Timothy F.↗

NASA NTRSDate not supplied

A 3D Simulation Platform for Decentralized Decision-Making in Advanced Air Mobility

This paper presents a general purpose, plug-and-play simulation platform for the use of future aviation stakeholders, such as urban airspace planners, air vehicle operators, ground operation managers, air traffic controllers and aviation researchers. The presented simulator platform is envisioned to serve as a toolkit to visualize, evaluate, and configure future advanced air mobility (AAM) operations. Highlighting features of this toolkit include a modular architecture that allows multiple smart unmanned aerial systems (UASs) to remotely connect to the simulation server and participate in decentralized decision-making scenario simulations. As an example of the decentralized decision-making scenario, an inter-agent negotiation-based conflict resolution use case is considered in this paper, where the UASs leverage the on-board/on-the-edge artificial intelligence (AI) capability to continually build situational awareness, and use this information to predict future conflicts and resolve them through machine-to-machine negotiation. As such operations are non-existent at scale currently, the presented simulation platform offers a viable and cost-effective alternative for assessing the efficacy of AAM research outcomes and challenges in future shared airspace usage. The simulation platform allows plug-n-play connectivity with AI and non-AI compute modules representing individual UAS’s flight control. Each module can interact with the simulation platform independently to communicate current and desired future states, situational awareness, and conflict resolution utilization costs for inter-agent negotiation. The simulation environment orchestrates realistic operational scenarios with spatiotemporal details, dynamic events, tactical conflict-resolution methods, interfaces for customizing air traffic control parameters, and information exchange uncertainties. In the future, this can serve as a community focused cloud simulation platform, incorporating multi-stakeholder airspace constraints from regulatory, government, city, and local agencies.

Aditya N Das↗

NASA NTRS2022

A 3D Simulation Platform for Decentralized Decision-Making in Advanced Air Mobility

This paper presents a general purpose, plug-and-play simulation platform for the use of future aviation stakeholders, such as urban airspace planners, air vehicle operators, ground operation managers, air traffic controllers and aviation researchers. The presented simulator platform is envisioned to serve as a toolkit to visualize, evaluate, and configure future advanced air mobility (AAM) operations. Highlighting features of this toolkit include a modular architecture that allows multiple smart unmanned aerial systems (UASs) to remotely connect to the simulation server and participate in decentralized decision-making scenario simulations. As an example of the decentralized decision-making scenario, an inter-agent negotiation-based conflict resolution use case is considered in this paper, where the UASs leverage the on-board/on-the-edge artificial intelligence (AI) capability to continually build situational awareness, and use this information to predict future conflicts and resolve them through machine-to-machine negotiation. As such operations are non-existent at scale currently, the presented simulation platform offers a viable and cost-effective alternative for assessing the efficacy of AAM research outcomes and challenges in future shared airspace usage. The simulation platform allows plug-n-play connectivity with AI and non-AI compute modules representing individual UAS’s flight control. Each module can interact with the simulation platform independently to communicate current and desired future states, situational awareness, and conflict resolution utilization costs for inter-agent negotiation. The simulation environment orchestrates realistic operational scenarios with spatiotemporal details, dynamic events, tactical conflict-resolution methods, interfaces for customizing air traffic control parameters, and information exchange uncertainties. In the future, this can serve as a community focused cloud simulation platform, incorporating multi-stakeholder airspace constraints from regulatory, government, city, and local agencies.

Aditya Das↗

NASA NTRS1988

Programming model for distributed intelligent systems

A programming model and architecture which was developed for the design and implementation of complex, heterogeneous measurement and control systems is described. The Multigraph Architecture integrates artificial intelligence techniques with conventional software technologies, offers a unified framework for distributed and shared memory based parallel computational models and supports multiple programming paradigms. The system can be implemented on different hardware architectures and can be adapted to strongly different applications.

Sztipanovits, J.↗

NASA NTRS1990

An automated environment for multiple spacecraft engineering subsystem mission operations

Flight operations at the Jet Propulsion Laboratory (JPL) are now performed by teams of specialists, each team dedicated to a particular spacecraft. Certain members of each team are responsible for monitoring the performances of their respective spacecraft subsystems. Ground operations, which are very complex, are manual, labor-intensive, slow, and tedious, and therefore costly and inefficient. The challenge of the new decade is to operate a large number of spacecraft simultaneously while sharing limited human and computer resources, without compromising overall reliability. The Engineering Analysis Subsystem Environment (EASE) is an architecture that enables fewer controllers to monitor and control spacecraft engineering subsystems. A prototype of EASE has been installed in the JPL Space Flight Operations Facility for on-line testing. This article describes the underlying concept, development, testing, and benefits of the EASE prototype.

Bahrami, K. A.↗

NASA NTRS1992

Distributed project scheduling at NASA: Requirements for manual protocols and computer-based support

The increasing complexity of space operations and the inclusion of interorganizational and international groups in the planning and control of space missions lead to requirements for greater communication, coordination, and cooperation among mission schedulers. These schedulers must jointly allocate scarce shared resources among the various operational and mission oriented activities while adhering to all constraints. This scheduling environment is complicated by such factors as the presence of varying perspectives and conflicting objectives among the schedulers, the need for different schedulers to work in parallel, and limited communication among schedulers. Smooth interaction among schedulers requires the use of protocols that govern such issues as resource sharing, authority to update the schedule, and communication of updates. This paper addresses the development and characteristics of such protocols and their use in a distributed scheduling environment that incorporates computer-aided scheduling tools. An example problem is drawn from the domain of Space Shuttle mission planning.

Richards, Stephen F.↗

NASA NTRS1993

Protocols for distributive scheduling

The increasing complexity of space operations and the inclusion of interorganizational and international groups in the planning and control of space missions lead to requirements for greater communication, coordination, and cooperation among mission schedulers. These schedulers must jointly allocate scarce shared resources among the various operational and mission oriented activities while adhering to all constraints. This scheduling environment is complicated by such factors as the presence of varying perspectives and conflicting objectives among the schedulers, the need for different schedulers to work in parallel, and limited communication among schedulers. Smooth interaction among schedulers requires the use of protocols that govern such issues as resource sharing, authority to update the schedule, and communication of updates. This paper addresses the development and characteristics of such protocols and their use in a distributed scheduling environment that incorporates computer-aided scheduling tools. An example problem is drawn from the domain of space shuttle mission planning.

Richards, Stephen F.↗

NASA NTRS1993

K- and Ka-band mobile-vehicular satellite-tracking reflector antenna system for the NASA ACTS mobile terminal

This paper describes the development of the K- and Ka-band mobile-vehicular satellite-tracking reflector antenna system for NASA's ACTS Mobile Terminal (AMT) project. ACTS is NASA's Advanced Communications Technology Satellites. The AMT project will make the first experimental use of ACTS soon after the satellite is operational, to demonstrate mobile communications via the satellite from a van on the road. The AMT antenna system consists of a mechanically steered small reflector antenna, using a shared aperture for both frequency bands and fitting under a radome of 23 cm diameter and 10 cm height, and a microprocessor controlled antenna controller that tracks the satellite as the vehicle moves about. The RF and mechanical characteristics of the antenna and the antenna tracking control system are discussed. Measurements of the antenna performance are presented.

Densmore, Art↗

NASA NTRS2019

UAS Integration in the NAS Detect and Avoid Subproject: Kitty Hawk - NASA Collaboration Discussion

NASA is conducting research under the UAS Integration in the NAS Project to develop standards that will enable mid-size and large unmanned aircraft to fly unrestricted in the National Airspace System. As these efforts move into its second phase, NASA is planning a series of flight tests and demonstrations, integrating industry partners' technologies. These events will not only provide valuable data to inform the RTCA Special Committee 228 DAA and C2 MOPS, but also provide an opportunity for the UAS community to test their technologies in a realistic environment. An overview of NASA UAS-NAS research will be presented touching on human systems integration, modeling and simulation and guidance and control. Plans for Flight Test 6 and Systems Integration Operationalization (SIO) will also be presented. The purpose of this meeting is to share with Kitty Hawk, at a high level, UAS-NAS research and discuss potential future collaboration between NASA and Kitty Hawk.

Shively, Jay↗

NASA NTRSDate not supplied

Extensible Traffic Management (xTM) - High-altitude Operations and Beyond

The technology development of balloons, airships, and high-altitude long-endurance (HALE) high-aspect-ratio wing aerial vehicles has expedited the deployment of high-altitude operations above Flight Level (FL) 600. It allows broader communication service area coverage than at ground level and enables efficient and precise earth observation to help address global climate change. Meanwhile, a record number of orbital launches were conducted in 2021. New mission concepts including those for small satellites, satellite constellations, suborbital tourism and point to point cargo transport are being developed. To enable efficient and safe operations of new-entrant vehicles and to alleviate the potential burden on air traffic controllers, the concept of Unmanned aircraft systems Traffic Management (UTM) explored a different approach requiring cooperative operations among operators/pilots through operational intent sharing and coordination. This concept has been extended and proposed by the community to handle traffic management for high-altitude operations. While the concept and basic system were tested in UTM, there are many critical capabilities needed for high-altitude operations. This talk will introduce the challenges brought by high-altitude operations and space operations and on-going research activities in developing critical capabilities for extensible traffic management at NASA.

Extensible Traffic Management↗

NASA NTRS1987

The effects of display-control I/O, compatibility, and integrality on dual-task performance and subjective workload

The utility of speech technology was evaluated in terms of three dual task principles: resource competition between the time shared tasks, stimulus central processing response compatibility, and task integrality. Empirical support for these principles was reviewed. Two studies investigating the interactive effects of the three principles were described. Objective performance and subjective workload ratings for both single and dual tasks were examined. It was found that the single task measures were not necessarily good predictors for the dual task measures. It was shown that all three principles played an important role in determining an optimal task configuration. This was reflected in both the performance measures and the subjective measures. Therefore, consideration of all three principles is required to insure proper use of speech technology in a complex environment.

Tsang, Pamela S.↗