41-50 of 63 results
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Experimental Testbed for the Validation of Autonomous ISAM/OSAM Systems
PI Morad Nazari
CO-I Kadriye Merve Dogan
CO-I Thomas Lovell
The ability to validate individual hardware and software components of these technologies on a large scale is still in its early stages. Thus, the goal of this research is to establish an effective experimental testbed for the validation of autonomous in-space servicing and maintenance (ISAM) / on-orbit servicing and maintenance (OSAM) systems.
A new era of affordable space flight, satellite refueling, on-orbit inspection, orbit transfer and end-of-life servicing has begun as a result of the space industry's continued focus on safe, resilient and adaptable space vehicles. These developments have laid the groundwork for assembly and manufacturing in orbit or space for potential use in active debris removal, reuse and recycling of materials. Advanced navigation and control technologies are required to ensure and lengthen the mission life cycles of these orbital assets, which include launch vehicles, satellites and space stations. Orbit/attitude determination, relative motion, robot manipulator kinematics and spacecraft rendezvous/docking can benefit from new advances in geometric mechanics Udwadia-Kalaba, adaptive control, learning, sensor fusion, computer vision and data communication. These efforts aim to equip future enterprises with the ability to perform in-space servicing and maintenance (ISAM) and on-orbit servicing and maintenance (OSAM) of failed or damaged space assets, as well as in-space manufacturing and platform assembly. However, the ability to validate individual hardware and software components of these technologies on a large scale is still in its early stages. Thus, the goal of this research is to establish an effective experimental testbed for the validation of autonomous ISAM/OSAM systems.Categories: Faculty-Staff
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Flexible Body Control Using Fiber Optic Sensors, Florida Space Grant Consortium
PI Morad Nazari
CO-I Daewon Kim
This project would build on previous research that developed the dynamics formulation and control of a rigid-flexible system.
This project would build on previous research that developed the dynamics formulation and control of a rigid-flexible system. A cantilevered beam attached to a rotating central body is considered and analyzed through the finite element method. A set of matrix differential equations are obtained to describe the dynamic behavior of the system, and a control law based on a Lyapunov function is obtained and applied to the system. The development of this dynamics formulation and control also considers the rigid-flexible coupling present in the system. The control law is designed such that the system can achieve and maintain a set of desired states for the central rigid body and flexible structure. The experimental measurements obtained from the implementation of FOS sensors on the flexible body and inertial sensors on the rigid body will be utilized as the input in this control design. The research portion of the project is anticipated to require one or two graduate student research assistants and a part-time academic advisor over a one-year period.
Categories: Faculty-Staff
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Reconfigurable Guidance and Control Systems for Emerging On-Orbit Servicing, Assembly and Manufacturing (OSAM) Space Vehicles
PI Morad Nazari
CO-I Kadriye Merve Dogan
In this project, the ControlX team with ERAU partnership will develop agile, reconfigurable, and resilient dynamics and G&C algorithms for on-orbit servicing to capture a broad set of OSAM applications such as remediation of resident space object (RSO) (e.g., via de-orbiting, recycle, end-of-life servicing, satellite refueling, etc.) using effective tools and methods involving geometric mechanics, constrained G&C synthesis, and reconfigurable robotic manipulators (RRMs).
Dynamic response to emergent situations is a necessity in the on-orbit servicing, assembly and manufacturing (OSAM) field because traditional on-orbit guidance and control (G&C) cannot respond efficiently and effectively to such dynamic situations (i.e., they are based on either constant mass or diagonal matrix of inertia). In these circumstances, the current challenge is to develop modeling strategies and control systems that exhibit intelligence, robustness and adaptation to the environment changes and disturbances (e.g., uncertainties, constraints and flexible dynamics). Note that the current state-of-the-art methods do not offer a reliable, accurate framework for real-time, optimal accommodation of constraints in the system dynamics that account for orbital-attitude coupling in the motion of the bodies without encountering singularity or non-uniqueness issues. In this project, the ControlX team with ERAU partnership will develop agile, reconfigurable, and resilient dynamics and G&C algorithms for on-orbit servicing to capture a broad set of OSAM applications such as remediation of resident space object (RSO) (e.g., via de-orbiting, recycle, end-of-life servicing, satellite refueling, etc.) using effective tools and methods involving geometric mechanics, constrained G&C synthesis, and reconfigurable robotic manipulators (RRMs).
The proposed work in this Phase I includes reconfigurable systems for on-orbit servicing, assembly and manufacturing with learning control methods that minimize tracking error of the end-effector of the RRM in the presence of uncertainties, optimize configuration and accommodate constraint-changing scenarios. Our developments will avoid singularity; not rely on the concept of costates or Lagrange multipliers that are restrictive; handle system uncertainties while enforcing the constraints; use RRMs in different tasks (recycle, debris removing, maintenance, etc.); not need in sensors or exact model knowledge for robotic arms. Specifically, constrained space vehicle control (predicated on Udwadia and Kalaba (UK) formalism) will offer not only accurate and resilient design but also reconfigurability in that G&C algorithms can easily be modified to suit a wide spectrum of OSAM applications. ControlX team will also consider the feasibility of hardware implementation. The selection of sensors, actuators and onboard computers will be an important trade-off between among size, weight, and power (SWaP) constraints, reliability, and computing performance. A real-time operating system (RTOS) is planned to meet timing and memory management constraints, partitioning hardware resources to control software application interactions. An analysis suite for the autonomous system implementation, based on system modeling and learning techniques, will provide onboard analysis, enabling decision-making as to whether the system can continue to meet mission requirements.
Categories: Faculty-Staff
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Investigation of Bio-Inspired Cylinders for Enhanced Heat Transfer
PI Anish Prasad
CO-I Yogesh Pai
CO-I Royce Fernandes
CO-I Mark Ricklick
This project investigates a novel cylinder design inspired from the Harbor Seal whisker, with the goal of reducing coolant pumping power requirements while maintaining heat transfer rates in pin-fin arrays.
Arrays of constant cross-section cylinders have been employed in many heat exchange applications. Increases in heat transfer rates characteristically result in an increase in the coolant pumping power requirements, which can be quite high for a circular cylinder array. Pin fin channels are often used at the trailing edge of the blades where they also serve an additional purpose of providing structural support. It has been found that the behavior of the flow around a wall-mounted cylinder significantly impacts the heat transfer. The boundary layer becomes broken up by the presence of the pin, creating a horseshoe vortex. This horseshoe vortex produces high wall shear stress beneath it, resulting in high heat transfer from the wall in this region. The resulting flow separation around the pin, however, results in large pressure losses. The pin fin channel has been heavily studied in the literature, in an effort to describe the heat transfer and flow behavior and improve prediction abilities. The circular cylindrical pins are relatively easy to manufacture and hence, this configuration is often found in commercial applications. However, the need to reduce pressure drop and maintain the heat transfer rates are a much needed requirement for a variety of industries to improve the cooling efficiency.
One such prominent line of research is conducted on optimizing the design of the circular cylindrical pins to increase their cooling performance. In this line of research, it was found that bio-mimicked harbor seal whisker geometry leads to the reduction in the cooling system pumping power requirements, while maintaining or improving heat transfer rates. The seal whisker geometry consists of stream-wise and span-wise undulations which reduce the size of the wake and coherent structures shed from the body as a result of an added component of stream-wise vorticity along the pin surface. Also, the vortex shedding frequency becomes less pronounced, leading to significantly reduced lateral loading on the modified cylinder. Preliminary computational studies have shown that the modified wake and vortex shedding structures resulting from the geometry tend to reduce the total pressure loss throughout the system without degrading the cooling levels.
Seal whisker and proposed bio-inspired cylinder:
Three different cross-section types, one elliptical, one of circular cross section and a 0.25X axially scaled type of the bio inspired pin were created for further investigation along with two baseline circular cylindrical and elliptical pins. Computational analysis for an array of the above three shapes and a standard elliptical cross-section pin array was undertaken. The results obtained were compared with the baseline circular cylindrical pin array. The main purpose of this research is to describe the heat transfer and flow characteristics of 3 novel bio inspired pin designs using steady and unsteady Reynolds-Averaged-Navier-Stokes (RANS) based simulations, in an effort to better understand their performance. These findings are important to the gas turbine community as reduced penalties associated with cooling flows directly translate to improved thermodynamic and propulsive efficiencies.
Pin-fin geometries analyzed:
Further computational research is being conducted in these geometries, and later will be compared with the experimental results, which will be carried out in Embry-Riddle's Gas Turbine Laboratory.
Categories: Graduate
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Investigate Detect and Avoid Track Classification and Filtering
PI Richard Prazenica
CO-I Troy Henderson
CO-I Morad Nazari
CO-I Tyler Spence
This research will identify key sources of uncertainty in representative detect and avoid architectures and assess the downstream risks and effects of spurious information on downstream system performance
In this project, which is funded by the FAA ASSURE program, the research team consisting of The Ohio State University, Embry‑Riddle Aeronautical University, Mississippi State University, University of North Dakota and Cal Analytics will work together to:
- Identify the key sources of misleading surveillance information produced by airborne and ground-based detect and avoid (DAA) systems. Develop risk modeling and analysis tools to assess the system-wide effects of false or misleading information on alerting and separation, as well as impacts on pilots in command (PIC) and air traffic operators.
- Provide guidance and recommendations for track classification and filter performance and safety requirements to standards bodies, including Radio Technical Commission for Aeronautics (RTCA) and American Society for Testing and Materials (ASTM) DAA working groups, and inform Federal Aviation Administration (FAA) rulemaking on DAA operations.
Current guidance provided by the Federal Aviation Administration has made beyond visual line of sight (BVLOS) missions an executive priority. Key to the success of these missions is the development of DAA systems capable of providing accurate pilot in the loop, or autonomous deconfliction guidance. Current standards for DAA services provided by RTCA and ASTM do not address the requirements for system performance with respect to generation of false or misleading information to the PIC or autonomous response services of the unmanned aircraft system. This research will identify key sources of uncertainty in representative DAA architectures and assess the downstream risks and effects of spurious information on downstream system performance. Additionally, recommendations will be developed for track classification accuracy requirements that provide sufficient safety margins for enabling DAA services in support of BVLOS missions.
Categories: Faculty-Staff
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Researching How You Teach Holistic Modeling (RHYTHM)
PI Kelsey Rodgers
CO-I Matthew Verleger
CO-I Lisa Davids
"Models are a critical part of the analysis and design of engineered systems. The purpose of multiple types of models (physical, mathematical, computational, and financial) is to provide a simplified representation of reality that mimics the features of the engineered system, and that predicts the behavior of the system. This project, a collaboration between Embry-Riddle Aeronautical University, San Jose State University, and the University of Louisville, aims to improve engineering students' modeling competence. The project plans to achieve this goal by transforming first-year engineering courses to teach modeling as an engineering tool. The project will change existing course materials, pedagogy, and assessment methods across the three institutions. Each institution will implement its own specific strategy to teach mathematical, physical, computational, and financial modeling, thus providing three different approaches. By comparing student's modeling abilities across the institutions and approaches, the project aims to identify the most impactful approaches for teaching multiple modeling in introductory undergraduate engineering courses.
The project is guided by a "holistic modeling perspective" theoretical framework, that builds on the successful "Models and Modeling Perspective" and "Computational Adaptive Expertise" frameworks. The objectives of the project are to: (1) implement, test, and refine holistic modeling environments for institutions that have flexibility in changing curriculum and for instructors that have different degrees of interest in changing their course(s); (2) implement, test, and refine methods to assess students' modeling abilities; and (3) evaluate and present the results of modeling abilities attained by students at three different universities. A unified language and discussion around modeling will be adopted in all revised courses. An assessment tool to measure students' modeling competence will be developed and implemented at each university. This work builds upon existing research in the development of more easily adaptable and adoptable modeling pedagogies and modeling languages. The following broad research question guides the research: How do students' definitional knowledge, ability to apply, and ability to create models change based on different degrees of modeling integration in the classroom?
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria."
Categories: Faculty-Staff
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Machine Learning for Dynamic Airspace Configuration towards Optimized Mobility in Emergency Situations
PI Houbing Song
Categories: Faculty-Staff
41-50 of 63 results