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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Telescope Parallel Actuator Mount: Control and Testing

Artho-Bentz, Samuel S 01 November 2020 (has links) (PDF)
This thesis approaches the task of designing a control system for the Parallel Actuator Mount developed by Dr. John Ridgely and Mr. Garrett Gudgel. It aims to create a base framework that directly controls the telescope and can be expanded to accept external command. It incorporates lower priced components and develops more easily approachable software with great functionality. An open-loop method for velocity control is established. Developing repeatable tests is a major focus. Testing finds the control methods developed result in velocity error of less than 5% and position error of less than 1.5% despite several mechanical issues and inaccuracies. Design guidelines are established that allow for the easy implementation of a Parallel Actuator Mount on other systems. This paper proves that the Parallel Actuator Mount is a potentially viable system for aiming a telescope when an astronomer does not require full sky coverage. The tests showed too much error to fully recommend the system as built and tested, but there are paths to increase accuracy of the system without greatly increasing the complexity or cost. The inclusion of a method of feedback, including a plate solver and an inertial measurement unit, would greatly improve the system. It may also be of use to modify the software to include a variable time step for the velocity control.
72

Telepresence: Design, Implementation and Study of an HMD-Controlled Avatar with a Mechatronic Approach

Chan, Darren Michael 01 June 2015 (has links) (PDF)
Telepresence describes technologies that allow users to remotely experience the sensation of being present at an event without being physically present. An avatar exists to represent the user whilst in a remote location and is tasked to collect stimuli from its immediate surroundings to be delivered to the user for consumption. With the advent of recent developments in Virtual Reality technology, viz., head-mounted displays (HMDs), new possibilities have been enabled in the field of Telepresence. The main focus of this thesis is to develop a solution for visual Telepresence, where an HMD is used to control the direction of a camera‟s viewpoint, such that the user‟s head is tracked by the avatar, while providing visual feedback to the user. The design and development of the device follows a mechatronic approach, where a real time operating system (RTOS) is used in conjunction with a microcontroller for mechanical actuator control. The first-generation prototype, HOG-1 (HMD-Operated Gimbal, rev. 1), developed for this thesis serves as a foundation for study; the implementation and analysis of the prototype contributes to the state of the art by providing a clearer glimpse of hardware and software requirements that are necessary to construct an improved model. Additionally, qualitative and quantitative measurements are developed in the process of this research.
73

Low-Cost Reaction Wheel Design for CubeSat Applications

Bonafede, Nicholas J, Jr. 01 August 2020 (has links) (PDF)
As science instruments on CubeSats become more sensitive to the attitude of the spacecraft, better methods must be employed to provide the accuracy needed to complete the planned mission. While systems that provide the accuracy required are available commercially, these solutions are not cost-effective, do not allow the design to be tailored to a specific mission, and most importantly, do not give students hand-on experience with attitude control actuators. This thesis documents the design, modeling, and simulation of a low-cost, student-fabricated, reaction wheel system for use in 3U CubeSat satellites. The entire design process for the development of this reaction wheel is based on fundamental design principles and can be replicated for either larger or smaller spacecraft as needed. Additionally, plans for bringing this design up to a prototyping and testing phase are outlined for continued use of this design in the Cal Poly CubeSat Laboratory.
74

A Concept Validation of a Magnetometry-Based Technology for Detecting Concealed Weapons in Vehicle Door Panels

Vang, Nar 01 August 2015 (has links) (PDF)
Acts of insurgency have become an increasing threat resulting in extensive measures being taken by the law enforcement authorities to mitigate their devastating effects on human life and infrastructure. This thesis introduces a magnetometry-based information, and signal processing methodology for detecting concealed ferrous objects in vehicle body panels. From extensive literature research, it was observed that while magnetic sensors have been used in a variety of related applications, but they have not been extensively applied to the on-road detection of firearms and explosives concealed in vehicles. This study utilized an extensive experimental protocol for preliminary concept validation. The main idea behind the approach was that almost all concealed weapons and explosives are made up of a considerable amount of ferrous material, and hence produce a local distortion in the Earth’s magnetic field. This distortion can then be identified by utilizing sensitive magnetic sensors. To detect concealed ferrous objects, magnetic signatures of a vehicle door panel were obtained by using a scanning assembly design in this thesis project, and compared to a base magnetic signature of the same vehicle door panel. The base magnetic signature is the magnetic field data of the same vehicle where no foreign ferrous objects were present. To analyze the data, a signal processing methodology was designed. To achieve the objective of accurately detecting concealed ferrous objects, simple measures such as magnetic field strength and its energy density were computed. These simple measures were then used in conjunction with more sophisticated statistical methods such as, normalized cross-correlation and Mahalanobis distance. Although all these methodologies were able to detect a magnetic footprint anomaly in the presence of a concealed object, the Mahalanobis distance approach, in particular provided the most conclusive results in all the test cases considered.
75

Dynamics Simulation and Optimal Control of a Multiple-Input and Multiple-Output Balancing Cube

Haimerl, Felix K 01 June 2018 (has links) (PDF)
This thesis document outlines the development of a multibody dynamics simulation of an actively stabilized multiple-input, multiple-output, coupled, balancing cube and the process of verifying the results by implementing the control algorithm in hardware. A non-linear simulation of the system was created in Simscape and used to develop a Linear Quadratic Gaussian control algorithm. To implement this algorithm in actual hardware, the system was first designed, manufactured, and assembled. The structure of the cube and the reaction wheels were milled from aluminum. DC brushless motors were installed into the mechanical system. In terms of electronics, a processor, orientation sensor, motor drivers, analog to digital converters, and a pulse width modulation board were assembled into the cube. Upon completion, the software to control the cube was developed using Simulink and run on a Raspberry Pi computer within the mechanism.
76

Pier Portal

Hardy, Alec W 01 June 2020 (has links) (PDF)
The Pier Portal marine monitoring system is an internet controlled underwater camera that will enable students, researchers, and the general public the ability to monitor underwater marine life and ocean conditions. Installed at Cal Poly’s Center for Coastal Marine Science pier at Avila Beach, California, the camera can be commanded in real-time to raise or lower to any position between the top of the pier and the bottom of the ocean floor, while providing a live-stream video to the operator and general public. This thesis effort focused on the integration of the various subsystem components through software, and the development of an online interface to allow the remote control of the system and the ability to view the live-stream video from the camera. Missing or damaged mechanical and electrical components were successfully redesigned and replaced, and a more compact and serviceable winch and sheave system was designed and partially manufactured. A software set was written in Python, JavaScript, HTML, and IEC 61131-6 successfully connecting the system’s control server, the winch’s industrial PLC, the cameras inside the underwater pod, and the front-facing webserver. The system’s internal network has been designed to allow internal components to communicate, and to allow external users the ability to securely control the system and view the video feed. Due to campus closure in early 2020, the final system was unable to be installed and tested, however, this document contains the entire system design and the next steps required to fully implement the system.
77

A Quantitative Approach for Tuning a Mountain Bike Suspension

Waal, Steven Robert 01 November 2020 (has links) (PDF)
A method for tuning the spring rate and damping rate of a mountain bike suspension based on a data-driven procedure is presented. The design and development of a custom data acquisition system, known as the "MTB DAQ," capable of measuring acceleration data at the front and rear axles of a bike are discussed. These data are input into a model that is used to calculate the vertical acceleration and pitching angular acceleration response of the bike and rider. All geometric and dynamic properties of the bike and rider system are measured and built into the model. The model is tested and validated using image processing techniques. A genetic algorithm is implemented with the model and used to calculate the best spring rate and damping rate of the mountain bike suspension such that the vertical and pitching accelerations of the bike and rider are minimized for a given trail. Testing is done on a variety of different courses and the performance of the bike when tuned to the results of the genetic algorithm is discussed. While more fine tuning of the model is possible, the results show that the genetic algorithm and model accurately predict the best suspension settings for each course necessary to minimize the vertical and pitching accelerations of the bike and rider.
78

Evaluation of Design Tools for the Micro-Ram Air Turbine

Villa, Victor Fidel 01 June 2015 (has links) (PDF)
The development and evaluation of the design of a Micro-Ram Air Turbine (µRAT), a device being developed to provide power for an autonomous boundary layer measurement system, has been undertaken. The design tools consist of a rotor model and a generator model. The primary focus was on developing and evaluating the generator model for the prediction of generator brake power and output electrical power with and without rectification as a function of shaft speed and electrical load, with only basic manufacturer specifications given as inputs. A series of motored generator evaluation test were conducted at speeds ranging from 9,000 to 25,000 rpm for loads varying between 1 and 3.02 Ohms with output power of up to 80 Watts. Results demonstrated that predicted generated power was at or below 3% error when compared to measured results with about 1% uncertainty. A rotor model was also developed using basic blade element theory. This model neglected induced flow effects and was therefore expected to over predict rotor torque and power. A second rotor model that includes induced flow effects, the open source program X-Rotor, was also used to predict rotor power and for comparison to the blade element rotor model results. Both rotor models were evaluated through wind tunnel validation tests conducted on a turbine generator with two different 3.25 in diameter rotors, rotor-1 (untwisted blades) and rotor-2 (twisted blades). Wind tunnel validation test airspeeds varied between 71-110 mph with electrical loads ranging from 1-20 ohms. Results indicated power predictions to be 50-75% higher for the blade element model and 20-30% for X-Rotor results. The blade element rotor model was modified by applying the Prandtl tip-loss factor to approximately account for the induced flow effects; this addition brought predictions much closer to X-Rotor results. Based on the motor-driven generator test results, it is believed that most of the discrepancy in baseline rotor/generator validation test between predicted and observed power generated is due to inaccuracy in the rotor performance modelling with likely contributors to error being induced flow effects, crude section lift/drag modelling, and aero-elastic deformation. It is concluded that the proposed generator model is sufficient although direct torque measurements may be desired and further development of the µRAT design tools should focus on an improved rotor performance model.
79

Design and Implementation of Eight-Legged Robotic Transporter

Depangher, Jeremy David 01 November 2013 (has links) (PDF)
This thesis contains the design, manufacturing, and testing of a functional eight-legged robotic transporter based on the concept design laid out in U.S. Patent 7,246,671. The device is intended to achieve three different sequences of motion: regular driving, obstacle climbing, and stair climbing. The prototype was carried through concept design, analysis, selection of materials and components, manufacturing, software development, and final assembly and testing. The device can be assembled under multiple configurations, which harbor certain advantages and disadvantages. The results of the testing encourage the continuation of a second iteration of this concept.
80

Modal analysis of electric motors using reduced-order modeling

Mathis, Allen, MATHIS 17 June 2016 (has links)
No description available.

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