Aerospace Engineering Commons^™

The Study Of Electrostatic And Magnetostatic Active Space Radiation Shielding For Deep Space Missions, Leroy A. Fung

Electrical & Computer Engineering Theses & Dissertations

A goal of the National Aeronautics and Space Administration (NASA) has been to develop technologies that will enable deep space explorations. Such missions include a prolonged stay on the Moon and the ability to sustain a long duration of travel time to Mars and beyond. Long-term human exposures to radiation are a crucial concern. Recent research has taken focus on active and passive shielding methods as a way of eliminating the hazard posed by radiation particles. Passive shielding involves the use of materials that has the ability to withstand radiation particles and reduce the dose by stopping or slowing the …

Dual High-Voltage Power Supply For Use On Board A Cubesat, Nicholas Weiser

Master's Theses

Since their conception in 1999, CubeSats have come and gone a long way. The first few that went into space were more of a “proof of concept,” and were more focused on sending simple data and photographs back to Earth. Since then, vast improvements have been made by over 40 universities and private firms, and now CubeSats are beginning to look towards interplanetary travel. These small satellites could provide a cost effective means of exploring the galaxy, using off the shelf components and piggy-backing on other launch vehicles with more expensive payloads. However, CubeSats are traditionally launched into Low Earth …

Gps Multipath Reduction With Correlator Beamforming, Jason M. Barhorst

Theses and Dissertations

This research effort investigates the feasibility of beamforming using a single Global Positioning System (GPS) front end. Traditional methods of beamforming use multiple front ends, typically one per antenna element. By enabling a receiver to sample a switched antenna array, the hardware cost of implementing a GPS antenna array can be significantly reduced. Similar techniques of reducing the number of receivers have been used by Locata Corporation in the design of their non-GPS positioning systems. However, Locata Corporation's local transmitters provide a signal strength much higher than GPS's signal strength. For this reason, the inclusion of low-noise amplifiers into the …

Development Of An Ionic Liquid Ferrofluid Electrospray Source And Mode Shape Studies Of A Ferrofluid In A Non-Uniform Magnetic Field, Edmond Joseph Meyer Iv

Dissertations, Master's Theses and Master's Reports - Open

An electrospray source has been developed using a novel new fluid that is both magnetic and conductive. Unlike conventional electrospray sources that required microfabricated structures to support the fluid to be electrosprayed, this new electrospray fluid utilizes the Rosensweig instability to create the structures in the magnetic fluid when an external magnetic field was applied. Application of an external electric field caused these magnetic fluid structures to spray. These fluid based structures were found to spray at a lower onset voltage than was predicted for electrospray sources with solid structures of similar geometry. These fluid based structures were also found …

Design And Evaluation Of A Propulsion System For Small, Compact, Low-Speed Maneuvering Underwater Vehicles, Florence M. Mbithi

Electronic Theses and Dissertations

Underwater vehicles used to perform precision inspection and non-destructive evaluation in tightly constrained or delicate underwater environments must be small, have low-speed maneuverability and a smooth streamlined outer shape with no appendages. In this thesis, the design and analysis of a new propulsion system for such underwater vehicles is presented. It consists primarily of a syringe and a plunger driven by a linear actuator and uses different inflow and outflow nozzles to provide continuous propulsive force. A prototype of the proposed propulsion mechanism is built and tested. The practical utility and potential efficacy of the system is demonstrated and assessed …

Filtered-Dynamic-Inversion Control For Fixed-Wing Unmanned Aerial Systems, Jon Mullen

Theses and Dissertations--Mechanical and Aerospace Engineering

Instrumented umanned aerial vehicles represent a new way of measuring turbulence in the atmospheric boundary layer. However, autonomous measurements require control methods with disturbance-rejection and altitude command-following capabilities. Filtered dynamic inversion is a control method with desirable disturbance-rejection and command-following properties, and this controller requires limited model information. We implement filtered dynamic inversion as the pitch controller in an altitude-hold autopilot. We design and numerically simulate the continuous-time and discrete-time filtered-dynamic-inversion controllers with anti-windup on a nonlinear aircraft model. Finally, we present results from a flight experiment comparing the filtered-dynamic-inversion controller to a classical proportional-integral controller. The experimental results show …

Extremum-Seeking For Nonlinear Discrete-Time Systems With Application To Hcci Engines, H. Zargarzadeh, S. Jagannathan, J. A. Drallmeier

Electrical and Computer Engineering Faculty Research & Creative Works

For many control applications, identifying an optimal operating point by maximizing/minimizing a performance function is important. This paper applies the extremum-seeking method to nonaffine, nonlinear discrete-time systems stabilized by an optimal adaptive controller. First, a novel averaging method is used for the nonlinear discrete-time systems to show that their output unique extrema are stable equilibrium points. Then, a singular perturbation method in discrete time is employed to show that the overall closed loop system will dynamically converge to the extremum. The applicability of this scheme is numerically verified on a Homogeneous Charge Compression Ignition (HCCI) model validated experimentally and expressed …

Identifiability Of Additive Actuator And Sensor Faults By State Augmentation, Suresh M. Joshi, Oscar R. Gonzalez, Jason M. Upchurch

Electrical & Computer Engineering Faculty Publications

A class of FDI (fault detection and identification) methods for bias-type actuator and sensor faults was explored from the point of view of fault identifiability. The methods use banks of Kalman-Bucy filters (KBFs) to detect faults, determine the fault pattern, and estimate the fault values. A complete characterization of conditions for identifiability of bias-type actuator faults, sensor faults, and simultaneous actuator and sensor faults was presented. It was shown that FDI of simultaneous actuator and sensor faults is not possible using these methods when all sensors have unknown biases. The fault identifiability conditions were demonstrated via numerical examples. The analytical …

Scalable Autonomous Operations Of Unmanned Assets, Sunghun Jung

Open Access Dissertations

Although there have been great theoretical advances in the region of Unmanned Aerial Vehicle (UAV) autonomy, applications of those theories into real world are still hesitated due to unexpected disturbances. Most of UAVs which are currently used are mainly, strictly speaking, Remotely Piloted Vehicles (RPA) since most works related with the flight control, sensor data analysis, and decision makings are done by human operators. To increase the degree of autonomy, many researches are focused on developing Unmanned Autonomous Aerial Vehicle (UAAV) which can takeoff, fly to the interested area by avoiding unexpected obstacles, perform various missions with decision makings, come …

Identifiability Of Additive, Time-Varying Actuator And Sensor Faults By State Augmentation, Jason M. Upchurch

Electrical & Computer Engineering Theses & Dissertations

Faults in dynamical systems can have serious safety and reliability implications. For example, actuator and sensor faults have been factors in past incidents and mishaps in many aerospace systems. A large body of research is devoted to developing methods to detect and identify actuator and sensor faults in such systems.

One fault detection and identification menthol employs state augmentation, whereby a set of time-varying faults of interest are modeled as outputs of exogenous linear, time-invariant systems and augmented to the state of the nominal system model. The resulting model represents the system dynamics due to a particular actuator-sensor fault configuration. …

Correlational Study Of Open Circuit Resonant (Sansec) Sensor’S Electric Field Distribution On Lightning Attachment, Kayla M. Farrow, Linda L. Vahala

Electrical & Computer Engineering Faculty Publications

NASA Langley Research Center (LaRC) is conducting research to develop an open circuit SansEC (Sans Electric Connection) sensor to provide lightning strike protection (LSP) in conjunction with damage detection and diagnosis for composite aircraft. SansEC sensors are simplistic devices consisting of an open circuit conductive trace shaped in a planar geometric spiral. The length and width of the conductive trace as well as the gap separation between adjacent turns determines the inductance, resistance and capacitance of the LRC circuit and its associated resonant response. When the sensor is placed on a composite substrate, the electric impedance of the substrate is …

Control System Infrastructure For The Cal Poly Human Powered Helicopter: Upturn Ii, Douglas A. Thornber, Samuel J. Wahyou

Aerospace Engineering

The Upturn was donated to Cal Poly in October 2012 by Neal Saiki from NTS. Our project was to replicate the old system to decrease the turn-around time in case of a crash during a test flight. The control system for the Upturn II was designed with the same considerations that were used for the Upturn. The result we got was inconclusive for the sensor selection, the new control system is heavier than the old system, and we couldn’t validate the system without doing a flight test. For the next iteration if some of the replication requirements are relaxed the …

Assessment For Completion Of Cp7 Integration With Revision 6 Avionics, Daniel Jennings

Electrical Engineering

he purpose of this project is the continuation of the CP7 CubeSat project, analysis for integration with new Avionics Systems, and to leave behind instruction for future work for completion of the satellite. CP7 is a satellite in development to support a mechanical and electrical system to experiment on particle damping in micro-gravity. The completion of this satellite needs to be prioritized more than it has been by the PolySat team to honor our work with Northrop Grumman, who have been supportive and helpful throughout the process. This work seeks to aid in the completion of this satellite, so that …

Low-Cost Imu Implementation Via Sensor Fusion Algorithms In The Arduino Environment, Brandon Mccarron

Aerospace Engineering

A multi-phase experiment was conducted at Cal Poly in San Luis Obispo, CA, to design a low-cost inertial measurement unit composed of a 3-axis accelerometer and 3-axis gyroscope. Utilizing the growing microprocessor software environment, a 3-axis accelerometer and 3-axis gyroscope simulated 6 degrees of freedom orientation sensing through sensor fusion. By analyzing a simple complimentary filter and a more complex Kalman filter, the outputs of each sensor were combined and took advantage of the benefits of both sensors to improved results. Gyroscopic drift was removed in the pitch and roll axes using the Kalman filter for both static and dynamic …

Design, Fabrication, And Testing Of An Emr Based Orbital Debris Impact Testing Platform, Jeffrey J. Maniglia Jr.

Master's Theses

This paper describes the changes made from Cal Poly’s initial railgun system, the Mk. 1 railgun, to the Mk. 1.1 system, as well as the design, fabrication, and testing of a newer and larger Mk. 2 railgun system. The Mk. 1.1 system is developed as a more efficient alteration of the original Mk. 1 system, but is found to be defective due to hardware deficiencies and failure, as well as unforeseen efficiency losses. A Mk. 2 system is developed and built around donated hardware from the Naval Postgraduate School. The Mk. 2 system strove to implement an efficient, augmented, electromagnetic …

High Frequency Magnetic Field Direction Finding Using Mgl-S8a B-Dot Sensors, Michael D. Archer

Theses and Dissertations

Aircraft based direction finding (DF) in the high frequency (HF) band is difficult due to the aircraft's size with respect to wavelength and limited azimuthal resolution. A B-dot sensor is useful for detection of the time varying magnetic field and offers improved integration into an aircraft. What the B-dot sensor gains in integration it gives up in sensitivity because it is designed for frequencies above 5 GHz. Design of an airborne HFDF array using Bdot sensors is based in maximizing the physical extent of the array and eliminating multiple main beams. The goals of this research are to complete a …

Real-Time Heading Estimation Using Perspective Features, James W. Dean

Theses and Dissertations

There are a large number of commercially available quad-rotor helicopters available from various manufacturers. All of these systems rely on a low cost MEMS based inertial measurement system for stabilization and navigation. These low cost inertial systems are all subject to rapid error growth in their attitude and position estimates unless bounded by external measurements. This thesis created real-time algorithm to integrate measurements from visual cues with measurements from onboard sensors to estimate the attitude position and velocity of a quad-rotor helicopter in a local navigation frame, a system model for the ARDrone, and a feed-back controller for the vehicle's …

Information Encoding On A Pseudo Random Noise Radar Waveform, Joshua A . Hardin

Theses and Dissertations

Navigation requires knowledge of current location and a planned destination. This is true with manned vehicles and unmanned vehicles. There are many ways to acquire the current location, including global positioning system (GPS), triangulation, radar, and dead reckoning. Today GPS is the most reliable and accurate navigation technique when there is a clear, unobstructed view of the satellite constellation. Various sensors can be used to perform indoor navigation; however, when the vehicle is autonomous the sensors need to provide the exact location to the system. This research determined if using a template replay strategy has the same RNR performance as …

Error Characterization Of Vision-Aided Navigation Systems, Daniel A . Marietta

Theses and Dissertations

The goal of this work is to characterize the errors committed by an Image Aided Navigation (IAN) algorithm that has been developed for use as a navigation tool in GPS denied areas. The filter under study was developed by the Air Force Institute of Technology's Advanced Navigation Technology center, and has been the focus of numerous research efforts. Unfortunately, these studies have all been based on single runs or simulations, and such results may not be indicative of the true filter performance. This problem extends to IAN publications in general; no analysis of IAN based upon a sizable real world …

Inertial Navigation System Aiding Using Vision, James O. Quarmyne

Theses and Dissertations

The aiding of an INS using measurements over time of the line of sight of ground features as they come into view of an onboard camera is investigated. The objective is to quantify the reduction in the navigation states' errors by using bearings-only measurements over time of terrain features in the aircraft's field of view. INS aiding is achieved through the use of a Kalman Filter. The design of the Kalman Filter is presented and it is shown that during a long range, wings level cruising flight at constant velocity and altitude, a 90% reduction in the aided INS-calculated navigation …

Adaptations And Analysis Of The Afit Noise Radar Network For Indoor Navigation, Russell D. Wilson Iv

Theses and Dissertations

After several years of development, the AFIT Noise Radar Network (NoNET) has proven to be an extremely versatile system for many standard radar functions. This pallet of capabilities includes through the wall target tracking capabilities due to its wide bandwidth and UHF operations. Utilizing White Gaussian Noise as its waveform, the NoNET can operate at much lower power levels than other comparable systems while remaining extremely covert. In an effort to explore new applications, the question arose could the NoNET provide a viable option for navigation capability in GPS denied and indoor environments? This research aims to provide proof of …

Materials Selection And Processing Techniques For Small Spacecraft Solar Cell Arrays, Naseem M. Torabi

Theses and Dissertations--Electrical and Computer Engineering

Body mounted germanium substrate solar cell arrays form the faces of many small satellite designs to provide the primary power source on orbit. High efficiency solar cells are made affordable for university satellite programs as triangular devices trimmed from wafer scale solar cells. The smaller cells allow array designs to pack tightly around antenna mounts and payload instruments, giving the board design flexibility. One objective of this work is to investigate the reliability of solar cells attached to FR-4 printed circuit boards. FR-4 circuit boards have significantly higher thermal expansion coefficients and lower thermal conductivities than germanium. This thermal expansion …

Information Measures For Statistical Orbit Determination, Alinda Kenyana Mashiku

Open Access Dissertations

The current Situational Space Awareness (SSA) is faced with a huge task of tracking the increasing number of space objects. The tracking of space objects requires frequent and accurate monitoring for orbit maintenance and collision avoidance using methods for statistical orbit determination. Statistical orbit determination enables us to obtain estimates of the state and the statistical information of its region of uncertainty given by the probability density function (PDF). As even collision events with very low probability are important, accurate prediction of collisions require the representation of the full PDF of the random orbit state. Through representing the full PDF …

An Attitude Determination System With Mems Gyroscope Drift Compensation For Small Satellites, Maxwell Bezold

Theses and Dissertations--Electrical and Computer Engineering

This thesis presents the design of an attitude determination system for small satellites that automatically corrects for attitude drift. Existing attitude determination systems suffer from attitude drift due to the integration of noisy rate gyro sensors used to measure the change in attitude. This attitude drift leads to a gradual loss in attitude knowledge, as error between the estimated attitude and the actual attitude increases.

In this thesis a Kalman filter is used to complete sensor fusion which combines sensor observations with a projected attitude based on the dynamics of the satellite. The system proposed in this thesis also utilizes …

Visual Attitude Propagation For Small Satellites, Samir Ahmed Rawashdeh

Theses and Dissertations--Electrical and Computer Engineering

As electronics become smaller and more capable, it has become possible to conduct meaningful and sophisticated satellite missions in a small form factor. However, the capability of small satellites and the range of possible applications are limited by the capabilities of several technologies, including attitude determination and control systems. This dissertation evaluates the use of image-based visual attitude propagation as a compliment or alternative to other attitude determination technologies that are suitable for miniature satellites. The concept lies in using miniature cameras to track image features across frames and extracting the underlying rotation.

The problem of visual attitude propagation as …

Unmanned Autonomous Object Retrieval: Old Dominion University 2013 International Aerial Robotics Competition Entry, Johnathan Bailey, Austin Boyd, Chung-Hao Chen, Stephen Dailey, Lisa Henderson, Jeremy Stuart, Christina Williams

Electrical & Computer Engineering Faculty Publications

This paper describes the design implementation of a Quadrotor Unmanned Aerial Vehicle (UAV) with the capability of exploring indoor locations without the assistance of external aids. For relative position, the use of a laser range sensor, an optical flow sensor, and sonar sensor combined allows for the vehicle to generate mapping information. With relative position in mind, the vehicle uses vision algorithms to recognize immediate obstacles, sign, and entry ways to allow for quick movement responses and object recognition. A proportional-integral-differentiator controller allows for flight stability and mitigation in the tight confines of the indoor spaces. A mapping algorithm allows …

Radar Based Navigation In Unknown Terrain, Kyle J. Kauffman

Theses and Dissertations

There is a great need to develop non-GPS based methods for positioning and navigation in situations where GPS is not available. This research focuses on the development of an Ultra-Wideband Orthogonal Frequency Division Multiplexed (UWB-OFDM) radar as a navigation sensor in GPS-denied environments. A side-looking vehicle-fixed UWB-OFDM radar is mounted to a ground or aerial vehicle continuously collecting data. A set of signal processing algorithms and methods are developed which use the raw radar data to aide in calculating the vehicle position and velocity via a simultaneous localization and mapping (SLAM) approach. The radar processing algorithms detect strong, persistent, and …

The Architecture Selection, Design, And Discharge Modeling Of A Passive Compensation, Iron-Core, Two-Phase, Permanent Magnet Compulsator To Power A Small Railgun Platform, Collin Macgregor

Aerospace Engineering

The goal of this project was to design and build a compensated pulsed alternator, or compulsator, to power the Cal Poly Electromagnetic Railgun Mark 1.1. This project examines the feasibility of implementing mechanical pulsed power supplies for repeatable use with a railgun load for orbital debris hypervelocity testing. The final system architecture chosen was a passively compensated, iron-core, 2-phase, permanent magnet compulsator. The Cal Poly Compulsator will be capable of storing 45 kJ of mechanical energy with a peak operating speed of 5,000 rpm at 190 V. Theoretical calculations resulted in the following predicted electrical performance values: a peak output …

Closed-Loop Thrust And Pressure Profile Throttling Of A Nitrous Oxide/Hydroxyl-Terminated Polybutadiene Hybrid Rocket Motor, Zachary W. Peterson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Hybrid motors that employ non-toxic, non-explosive components with a liquid oxidizer and a solid hydrocarbon fuel grain have inherently safe operating characteristics. The inherent safety of hybrid rocket motors offers the potential to greatly reduce overall operating costs. Another key advantage of hybrid rocket motors is the potential for in-flight shutdown, restart, and throttle by controlling the pressure drop between the oxidizer tank and the injector. This research designed, developed, and ground tested a closed-loop throttle controller for a hybrid rocket motor using nitrous oxide and hydroxyl-terminated polybutadiene as propellants. The research simultaneously developed closed-loop throttle algorithms and lab scale …

Advancing The Beamed Energy Ablation Driven Propulsion Engine Concept, Grant Bergstue

Von Braun Symposium Student Posters

No abstract provided.