Navigation, Guidance, Control and Dynamics Commons^™

Three-Axis Stabilized Earth Orbiting Spacecraft Simulator, Alan F. Ma, Nikola N. Dominikovic

Aerospace Engineering

This report details the method and results of the program created for simulating an Earth orbiting spacecraft with control actuators and orbital perturbations. The control actuators modeled are reaction thrusters, reaction/momentum wheels, and control moment gyros (CMG). The perturbations modeled were gravity gradient, electromagnetic torques, solar radiation pressure, gravity gradients, third-body effects, Earth oblateness and atmospheric drag. This simulation allows for satellite control in all 6 degrees of freedom for any Earth orbiting spacecraft. Assumptions include rigid body dynamics, no sensor noise, constant spacecraft cross-sectional area, constant coefficient of drag and reflectivity, ignoring the effects due to the moon, moment …

Control System Development For Small Uav Gimbal, Nicholas J. Brake

Master's Theses

The design process of unmanned ISR systems has typically driven in the direction of increasing system mass to increase stabilization performance and imagery quality. However, through the use of new sensor and processor technology high performance stabilization feedback is being made available for control on new small and low mass stabilized platforms that can be placed on small UAVs. This project develops and implements a LOS stabilization controller design, typically seen on larger gimbals, onto a new small stabilized gimbal, the Tigereye, and demonstrates the application on several small UAV aircraft. The Tigereye gimbal is a new 2lb, 2-axis, gimbal …

Comprehensive Matlab Gui For Determining Barycentric Orbital Trajectories, Steve Katzman

Aerospace Engineering

When a 3-body gravitational system is modeled using a rotating coordinate frame, interesting applications become apparent. This frame, otherwise known as a barycentric coordinate system, rotates about the system’s center of mass. Five unique points known as Lagrange points rotate with the system and have numerous applications for spacecraft operations. The goal of the Matlab GUI was to allow easy manipulation of trajectories in a barycentric coordinate system to achieve one of two end goals: a free-return trajectory or a Lagrange point rendezvous. Through graphical user input and an iterative solver, the GUI is capable of calculating and optimizing both …

Development Of A Pyrotechnic Shock Simulation Apparatus For Spacecraft Applications, Joseph Binder, Matthew Mccarty, Chris Rasmussen

Aerospace Engineering

This report details the research, design, construction, and testing of a pyrotechnic shock simulation apparatus for spacecraft applications. The apparatus was developed to be used in the Space Environments Lab at California Polytechnic State University. It will be used for testing spacecraft components with dimensions up to 24”x12”x12” as well as CubeSats. Additionally, it may be used as an instructional or demonstrational tool in the Aerospace Department’s space environments course. The apparatus functions by way of mechanical impact of an approximately 20 lb stainless steel swinging hammer. Tests were performed to verify the simulator’s functionality. Suggestions for improvement and further …

Empennage Sizing And Aircraft Stability Using Matlab, Ryan C. Struett

Aerospace Engineering

No abstract provided.

Flying Qualities Built-In-Test For Unmanned Aerial Systems, Alton Pak-Hin Chiu

Master's Theses

This paper presents a flying qualities built-in-test for UAS application with the scope limited to the longitudinal axis. A doublet input waveform excites the AV and both α and q are used by EUDKF to estimate the A and B matrices which are short period approximations of the system. ζ, ω, GM, PM, observability, and controllability are calculated to determine flying qualities with the results displayed to the AVO in a color-coded, easy to interpret display.

While SID algorithms have been flying in vehicles with adaptive control schemes, vehicles with other schemes (such as classical feedback) lack this built-in self …

Sun-Synchronous Orbit Slot Architecture Analysis And Development, Eric Watson

Master's Theses

Space debris growth and an influx in space traffic will create a need for increased space traffic management. Due to orbital population density and likely future growth, the implementation of a slot architecture to Sun-synchronous orbit is considered in order to mitigate conjunctions among active satellites. This paper furthers work done in Sun-synchronous orbit slot architecture design and focuses on two main aspects. First, an in-depth relative motion analysis of satellites with respect to their assigned slots is presented. Then, a method for developing a slot architecture from a specific set of user defined inputs is derived.

Nonlinear Uav Flight Control Using Command Filtered Backstepping, Brian M. Borra

Master's Theses

The aim of this effort is to implement a nonlinear flight control architecture, specifically flight path control via command filtered backstepping, for use in AME UAS's Fury® 1500 unmanned flying wing aircraft. Backstepping is a recursive, control-effort minimizing, constructive design procedure that interlaces the choice of a Lyapunov function with the design of feedback control. It allows the use of certain plant states to act as intermediate, virtual controls, for others breaking complex high order systems into a sequence of simpler lower-order design tasks.

Work herein is a simplified implementation based on publications by Farrell, Sharma, and Polycarpou. Online approximation …

Aircraft Longitudinal Control Experiment, Dustin Schaff

Aerospace Engineering

This paper describes the design, fabrication, and analysis of an experiment that demonstrates the stability and control system characteristics of an aircraft constrained at the center of gravity in an air flow field. Given a set of basic requirements, the physical system (including the airframe, wings, tail, and mounted ball bearing) was designed, modeled, and manufactured. With the aircraft placed in front of a fan and allowed to rotate freely with the ball bearing, an angular rate sensor and servo motor to the deflect the elevator may be connected to any computer using an analog/digital Data Acquisition (DAQ) device to …

Global Optimization Of Mga-Dsm Problems Using The Interplanetary Gravity Assist Trajectory Optimizer (Igato), Jason M. Bryan

Master's Theses

Interplanetary multiple gravity assist (MGA) trajectory optimization has long been a field of interest to space scientists and engineers. Gravity assist maneuvers alter a spacecraft's velocity vector and potentially allow spacecraft to achieve changes in velocity which would otherwise be unfeasible given our current technological limitations. Unfortunately, designing MGA trajectories is difficult and in order to find good solutions, deep space maneuvers (DSM) are often required which further increase the complexity of the problem. In addition, despite the active research in the field over the last 50 years, software for MGA trajectory optimization is scarce. A few good commercial, and …

Comet: Constrained Optimization Of Multiple-Dimensions For Efficient Trajectories, Michael Curt Conrad

Master's Theses

The paper describes the background and concepts behind a master’s thesis platform known as COMET (Constrained Optimization of Multiple-dimensions for Efficient Trajectories) created for mission designers to determine and evaluate suitable interplanetary trajectories. This includes an examination of the improvements to the global optimization algorithm, Differential Evolution, through a cascading search space pruning method and decomposition of optimization parameters. Results are compared to those produced by the European Space Agency’s Advanced Concept Team’s Multiple Gravity Assist Program. It was found that while discrepancies in the calculation of ΔV’s for flyby maneuvers exist between the two programs, COMET showed a noticeable …

An Analysis Of Stabilizing 3u Cubesats Using Gravity Gradient Techniques And A Low Power Reaction Wheel, Erich Bender

Aerospace Engineering

The purpose of this paper is to determine the feasibility of gravity gradient stabilizing a 3U CubeSat and then using a miniature reaction wheel to further increase stability characteristics. This paper also serves as a guide to understanding and utilizing quaternions in attitude control analysis. The analytical results show that using 33 centimeter booms and 400 gram tip masses, a 3U CubeSat will experience a maximum of 6 degrees of angular displacement in yaw and pitch, and less than .5 degrees of angular displacement in the nadir axis. A .120 kilogram miniature reaction wheel developed by Sinclair Interplanetary was introduced …

Development And Design Of A Hovering Controller For Operation In A Dynamic Asteroid Environment, Nicholas Georgiades

Aerospace Engineering

The project seeks to develop a dynamic model similar to that present near a solar system small body, and to design a controller suggested in other resources that will allow a spacecraft operating in this environment to hover in a fixed location in the relative reference frame of the small body. The paper discusses the derivation of the equations of motion used in the non-linear dynamic model, the design of the controller that will allow the spacecraft to hover, and the development of the control loop that will simulate the spacecraft hovering in the dynamic environment of the asteroid 1999 …

Boom Stability Control Final Project Report, Michael Barnes, Justin Carnahan, Daniel Fluitt, Alicia Johnstone

Mechanical Engineering

The BOOMStiC Gravity Gradient Boom and Turnstile Antenna project was developed to provide a passive attitude control system and better communications for future CubeSat satellites developed by California Polytechnic State University. The system utilizes the energy from a coilable metal spring to deploy a tip mass to a length of one meter from the side of the satellite. Calculations show the resulting gravity gradient torque causes to the satellite to settle two degrees from normal to the earth’s surface.

Imu Integration To The Cal Poly Spacecraft Attitude Dynamics Simulator Power System, Wayland Chan

Electrical Engineering

The Cal Poly Spacecraft Attitude Dynamics Simulator mimics the rotation dynamics of a spacecraft in orbit and acts as a test bed for spacecraft attitude control system development and demonstration. Prior to this project, the simulator measured its attitude dynamics from a total of seven sensors mounted on to the platform, including three micro-electromechanical system (MEMs) gyroscopes, and four motor encoders. This project entails the installation of an LN-200 high performance gyroscope, which will provide a greater measure of accuracy. The goal of this project is to design a power circuit that will integrate the LN-200 inertial measurement unit onto …

Integration Of Aeroservoelastic Properties Into The Nasa Dryden F/A-18 Simulator Using Flight Data From The Active Aeroelastic Wing Program, Alexander Wong Chin

Master's Theses

Aircraft structures have varying stiffness levels making them flexible. Consequently, this elastic property becomes increasingly important at high speeds affecting the flight dynamics of the aircraft.  In high speed aircraft such as the F/A-18, elastic structural properties must be accounted for to ensure confidence in predicted flight dynamics in order to avoid adverse aeroelastic phenomena throughout flight.

Data from the F/A-18 Active Aeroelastic Wing (AAW) program was used to create aeroservoelastic (ASE) models at varying flight conditions. The discretized ASE models were integrated into the NASA Dryden F/A-18 simulator in parallel with the traditional 6-DOF (degrees-of-freedom) flight dynamics calculations to …

Aether, Thomas Cameron, Kristine Colton, Daren Childers

Electrical Engineering

Aether is a RC-style autonomous air vehicle that utilizes GPS positioning along with a wireless communication system to achieve a computer-controlled flight.

This report will incorporate the acquisition, design, integration, implementation and testing phases of the UAV development. Furthermore a discussion of troubleshooting as well as improvements for future projects will be included.

Flight Testing In A Simulation Based Environment, David W. Babka

Aerospace Engineering

Over the past two decades performance flight testing of full scale aircraft has transferred some of the testing workload to simulation based systems.  Flight testing full scale aircraft in the real world environment has always been expensive, especially now with the rise in aviation fuel costs. Additionally, new emerging technologies require extensive testing and doing so in the full scale environment is cost prohibitive.  A cheaper alternative is to test systems in a simulation based environment.  Not only can aircraft be simulated via a computer, but all the aircrafts systems can be modeled in the simulation.  Furthermore, most of the …

Modeling Of A Gyro-Stabilized Helicopter Camera System Using Neural Networks, Nicholas Joseph Layshot

Master's Theses

On-board gimbal systems for camera stabilization in helicopters are typically based on linear models. Such models, however, are inaccurate due to system nonlinearities and complexities. As an alternative approach, artificial neural networks can provide a more accurate model of the gimbal system based on their non-linear mapping and generalization capabilities.

This thesis investigates the applications of artificial neural networks to model the inertial characteristics (on the azimuth axis) of the inner gimbal in a gyro-stabilized multi-gimbal system. The neural network is trained with time-domain data obtained from gyro rate sensors of an actual camera system. The network performance is evaluated …

Modeling And Simulation Of Autonomous Thermal Soaring With Horizon Simulation Framework, Zhenhua Li

Master's Theses

A thermal is a column of warm rising air triggered by differential heating on the ground. In recent studies UAVs were programmed to exploit this free atmospheric energy from thermals to improve their range and endurance. Researchers had successfully flown UAVs autonomously with thermal soaring method. Most research involved some form of flight simulation. Improvements to the aircraft and thermal models for simulation purpose would enable researchers to better design their UAVs and explore any potential flaws in their designs. An aircraft simulation with a thermal environment was created in Horizon Simulation Framework, a modeling and verification framework that was …

Hot Air Balloon Navigation, Dustin Blackwell

Aerospace Engineering

This report describes a program used for navigating a hot air balloon.  The program, Balloon_Trip, was written using MATLAB and gives a flight path to follow from a start position to an end position.  Balloon_Trip calculates the flight path by taking in wind conditions and then flying through these different winds so as to steer the hot air balloon.  The program calculates the flight path by taking into consideration at all times how the wind will propel the balloon while it is rising or falling in elevation.  It then takes the most direct and least complicated, if not fastest, …

Interplanetary Gravity Assisted Trajectory Optimizer (Igato), Jason Bryan

Aerospace Engineering

Interplanetary space travel is an extremely complicated endeavor that is severely limited by our current technological advancements. The amount of energy required to transport a spacecraft from one planet to the next, or even further, is extraordinary and in some cases is even impossible given our current propulsive capabilities. Due to these complications, the search for other means of exchanging energy became imperative to future space exploration missions. One particularly powerful method that was discovered, and the most commonly used one, is referred to as planetary gravity assist. In order to plan out multiple gravity assist trajectories, complex and robust …

Autonomous Control Of The Cal Poly Motion Flight Simulator, Andrew M. Anderson

Aerospace Engineering

An autonomous controller for the Cal Poly Motion Flight Simulator was developed such that the simulated Van’s RV-7 flies a standard light aircraft traffic pattern without any human pilot input. First, an autopilot was developed in Simulink to control the aircraft’s altitude, airspeed, and heading independent of each other. The performance of the autopilot has been tested to perform with a response sufficient for precise navigation. A C++ s- function was written as a mission controller that followed a pre-programmed path around a known airport. The aircraft performs a standard left 45 degree entry into the traffic pattern, lands on …

Senior Project: Global Position Determination From Observed Relative Position Of Celestial Bodies, Michael Holmes

Aerospace Engineering

A method was developed to determine the latitude and longitude of an observer based on the observed position of the Moon and several other celestial bodies. The basic principal developed dealt with the proximity of the Moon. Its relative displacement from calculated values was measured using photography by comparison with stars near the Moon. Photographs were taken from a location in San Luis Obispo at Longitude 120°35.9' and Latitude 35°13.3'. The analysis method has determined the location of the observer to a Longitude of 117°43.8'. An additional method located the observer to 36°38.7'N Latitude and 114°47.6'W Longitude.

Applied System Identification For A Four Wheel Reaction Wheel Platform, Seth F. Silva

Master's Theses

Applied System Identification for a Four Wheel Reaction Wheel Platform

By

Seth Franklyn Silva

At the California Polytechnic State University, San Luis Obispo there is a four-wheel reaction wheel pyramidal simulator platform supported by an air-bearing. This simulator has the current capability to measure the wheel speeds and angular velocity of the platform, and with these measurements, the system identification process was used to obtain the mass properties of this simulator. A handling algorithm was developed to allow wireless data acquisition and command to the spacecraft simulator from a “ground” computer allowing the simulator to be free of induced torques …

System Integration And Attitude Control Of A Low-Cost Spacecraft Attitude Dynamics Simulator, Ryan L. Kinnett

Master's Theses

The CalPoly Spacecraft Attitude Dynamics Simulator mimics the rotational dynamics of a spacecraft in orbit and acts as a testbed for spacecraft attitude control system development and demonstration. Prior to this thesis, the simulator platform and several subsystems had been designed and manufactured, but the total simulator system was not yet capable of closed-loop attitude control. Previous attempts to make the system controllable were primarily mired by data transport performance. Rather than exporting data to an external command computer, the strategy implemented in this thesis relies on a compact computer onboard the simulator platform to handle both attitude control processing …

Adaptive Control Applied To The Cal Poly Spacecraft Attitude Dynamics Simulator, Matthew C. Downs

Master's Theses

The goal of this thesis is to use the Cal Poly Spacecraft Attitude Dynamics Simulator to provide proof of concept of two adaptive control theories developed by former Cal Poly students: Nonlinear Direct Model Reference Adaptive Control and Adaptive Output Feedback Control. The Spacecraft Attitude Dynamics Simulator is a student-built air bearing spacecraft simulator controlled by four reaction wheels in a pyramidal arrangement. Tests were performed to determine the effectiveness of the two adaptive control theories under nominal operating conditions, a “plug-and-play” spacecraft scenario, and under simulated actuator damage. Proof of concept of the adaptive control theories applied to attitude …

Control Law Design And Validation For A Helicopter In-Flight Simulator, Brian T. Fujizawa

Master's Theses

In-flight simulation allows one aircraft to simulate the dynamic response of another aircraft. A control system designed to give RASCAL, a JUH-60A Black Hawk helicopter based at Moffett Field, CA, in-flight simulation capabilities has been designed, optimized and validated in this research. A classical explicit model following control system with a frequency dependent feedback controller was used. The frequency dependent controller allows model following of the attitude in the short term and the velocity in the long term. Controller gains were optimized using a high order, linearized model of UH-60 dynamics. Non-linear simulations of the control laws were performed, first …

On-Board Orbit Determination And 3-Axis Attitude Determination For Picosatellite Applications, John Arthur Bowen

Master's Theses

This thesis outlines an orbit determination and 3-axis attitude determination system for use on orbit as applicable to 1U CubeSats and other picosatellites. The constraints imposed by the CubeSat form factor led to the need for a simple configuration and relaxed accuracy requirements. To design a system within the tight mass, volume, and power constraints inherent to CubeSats, a balance between hardware complexity, software complexity and accuracy is sought. The proposed solution consists of a simple orbit propagator, magnetometers with a magnetic field look-up table, Sun sensors with an analytic Sun direction model, and the TRIAD method to combine vector …

Satellite Formation Flight Navigation Using The Clohessy-Wiltshire Equations, Anna Kimmich

Aerospace Engineering

This report presents the design and simulation of a satellite navigation program using Matlab. The program allows any number of independent satellites to navigate in a co-planar cluster formation in a circular orbit with no input besides its location coordinates from a simulated GPS unit and the relative location of other satellites from a simulated on-board sensor. This navigation program uses a potential field-like function to calculate the desired satellite position within the formation. It uses the Clohessy-Wiltshire equations to calculate the impulsive maneuvers needed to achieve and maintain the formation.