Engineering Commons^™

Modular Approach To Soft Mobile Robots, Dimuthu Kodippili Arachchige

College of Computing and Digital Media Dissertations

Soft robot locomotion is a highly promising but under-researched subfield within the field of soft robotics. The compliant limbs and bodies of soft robots offer numerous benefits, including the ability to regulate impacts, tolerate falls, and navigate through tight spaces. These robots have the potential to be used for various applications, such as search and rescue, inspection, surveillance, and more. The state-of-the-art still faces many challenges, including limited degrees of freedom, a lack of diversity in gait trajectories, insufficient limb dexterity, limited payload capabilities, lack of control methods, etc. To address these challenges, this research introduces a modular approach to …

Sliding Mode Control With Chattering Reduction, Suryamshu Ramesh

Doctoral Dissertations and Master's Theses

Sliding Mode Control is a powerful nonlinear control methodology that can handle parametric uncertainties and external disturbances. However, the discontinuous and high-frequency switching nature of the control law introduces the chattering phenomenon, which leads to potential actuator degradation, alterations to the desired response characteristics and, sometimes, instability during control implementation. The main objective of this thesis is to study Sliding Mode Control with chattering reduction. The Sliding Mode Control law involves an equivalent control component and a discontinuous control component. A disturbance estimation is performed based on Lyapunov analysis and adaptive control techniques and then included in the control law …

Automatic Mass Balancing Of A Spacecraft Attitude Dynamics Simulator With Six Sliding Masses, Amelia J. Gilman

Master's Theses

The goal of this thesis is to investigate automatic mass balancing methods for spacecraft attitude dynamics simulators, create a hardware design for a mass balancing system, and assemble the hardware on the Cal Poly Spacecraft Attitude Dynamics Simulator (SADS). Spacecraft attitude dynamics simulators replicate the torque-free environment of space with ground-based hardware. The SADS is mounted on a spherical air bearing, and includes a pyramid of four reaction wheels. The air bearing allows frictionless, unbounded rotation about the vertical axis, and 30 degrees about the horizontal axes. The torque-free configuration of the SADS can be used to test spacecraft attitude …

The Development And Enhancement Of A Forward Mathematical Model Of The Human Knee Joint, Seth Coomer

Doctoral Dissertations

Degenerative joint disease, or osteoarthritis, is a common occurrence in the knee joint. This can often result in joint pain, decrease in range of motion, and ultimately disability. One way to counteract osteoarthritis is the incorporation of a total knee arthroplasty (TKA). TKAs replace the damaged bone and soft tissue surrounding the knee with metal and polyethylene components. Ideally this will improve the joint’s performance and reduce pain. However, there is still a number of TKA patients who remain dissatisfied. In order to investigate this, in depth research must be done on the design and performance of TKAs.

One such …

A Transdisicplinary, Survivor-Centered Approach For Creating A System Dynamics Model Of Closed-Buyer Sex Trafficking Networks, Kemonte Yow

All Theses

One of the largest drivers of sex trafficking operations is the demand for commercial sex. To date, research from a quantitative side typically focuses on understanding how to best identify and remove victims from their trafficking situation and then support their healing and recovery. This may be because this is where data exists (in limited forms) to support quantitative modeling. This thesis broadens that scope to understand how demand for commercial sex impacts trafficking operations. In particular, this research implemented a transdisciplinary, survivor-centered approach to build a system dynamics model of a closed-buyer sex trafficking network, which is a network …

Application Of The Fokker-Planck Equation For Quantifying Initial Condition Uncertainty Of Reversible Dynamic Systems, Troy S. Newhart

Mechanical & Aerospace Engineering Theses & Dissertations

Characterizing the behavior of dynamic systems requires the inclusion of initial conditions to propagate behavior forward in time. More realistic representations of system behavior quantify uncertainty about the initial conditions to assess sensitivity, reliability, and other stochastic response parameters. In many engineering applications, the uncertain initial conditions may be unknown given a desired response. This research applies the Fokker-Planck equation to reversible dynamic systems of select multi-dimensional nonlinear differential equations as a means for predicting the uncertainty about initial conditions. An alternating directions implicit numerical scheme is used to numerically solve the Fokker-Planck equation for both forward and reversed equations …

A One-Wheeled Robot For Exploring Rolling Disk Locomotion, David H. J. Schmidt

Graduate Research Theses & Dissertations

The work proposed in this thesis is motivated by observations of one-wheel vehicles called monocycles. Whereas the unicycle has the rider sitting on a seat above the wheel, the monocycle’s rider sits inside a large circular hoop that serves as the wheel. Due to the position of the rider inside the wheel, it lowers the overall center of mass of the vehicle below the center of the wheel. For this reason, the uncontrolled longitudinal (forward/backward, or drive axis) dynamics are stable. For modest speeds above a certain threshold, the lateral (side-to-side, or lean axis) dynamics of the monocycle are also …

Travel Time Theory For Traffic Conservation Laws With Applications, Sergio Contreras

UNLV Theses, Dissertations, Professional Papers, and Capstones

Travel time is an important concept in various intelligent transportation system (ITS) applications. The concept is used in a wide array of applications, such as system planning, system performance, and optimization. Reducing the time required to travel between different points on a network is an important goal. Benefits include reducing time wasted in traveling, and keeping travelers satisfied. Thus, studying and reducing travel time in ITS is beneficial in different applications.

The classic density-based Lighthill Whitman Richards (LWR) equation for modeling traffic flow is the starting point in this dissertation. A more recent travel time dynamics function built on top …

Analysis Of A Nanoparticle’S Dynamics In An Optical Tweezer, Vatsal Asitkumar Joshi

Mechanical and Aerospace Engineering Dissertations

This work presents a simulation and experimental analysis of a nanoparticle's motion in an optical tweezer. Specifically, different simulation and analysis techniques are developed to investigate a suspected regime change in the dynamics of the micro/nano particles from overdamped to underdamped motion as the particle size reduces to submicron scale. Moreover, the simulation techniques developed here provide accurate prediction of the particle dynamics along with low computation time. Finally, the experimental setup developed here provides new experimental data that help answer the question of the regime change with increased certainty. Micro- and nano- scale systems, such as an optical tweezer, …

Uncertainty Quantification And Constraint Of Chemical Kinetic Mechanisms Based On Flow Reactor Experiments, Ana Victoria Kock

Theses and Dissertations

The chemical kinetic model is one of key sub-models for computational fluid dynamics (CFD) simulation for optimizing and designing various combustors/engines. Detailed chemical kinetic models can consist of hundreds of species and thousands of elementary reaction steps. Considering the complexity in these detailed chemical kinetic models, it is important to quantify and minimize the uncertainties in the kinetic parameters. The uncertainties in the kinetic models can then be compared to uncertainties tied to experimental measurements. This approach has been frequently applied for relatively simple combustion parameters (e.g., laminar flame speed, ignition delay time), however it has not been well utilized …

Dynamics And Steering Of A Vibration-Driven Bristle Bot In A Pipe System, Ian Stewart

All Theses

Soft vibrational robots are robots that incorporate compliant structures into their design and are driven by oscillating actuators. A recent, popular version of a soft vibrational robot is the bristle bot, which uses flexible bristles and a vibration motor to propel itself across surfaces and through pipes. This motion is primarily driven by stick-slip dynamics resulting from asymmetric frictional forces applied at the bristle tips. Depending on the frequency of vibration of the motor, the robot experiences various resonance regions allowing it to maneuver in different directions. Attaching bristles to all sides of the robot and placing it in a …

Locking Solar Tracking Bushing, Benjamin James Reed, Andrew Donald Maas, Angel Navarro-Iniguez, John Vincent Bruner

Mechanical Engineering

The contents of this final design review (FDR) outline the progress made by a team of four mechanical engineering students at California Polytechnic State University, San Luis Obispo to solve the problem of torsional galloping in solar tracker panels since the preliminary design review. The project proposed by the sponsor, Christian Friedrich, on behalf of ARaymond is a design for a friction based braking system integrated into a redesigned bushing.

The CDR contains details about the system design, the design justification, the manufacturing plan, and design verification plan. In the system design section, the four manufacturing subsystems (bushing mount, actuation, …

Environmental Exploration With Long, Thin Tendril Robots, Or Building Plant Based Robots And Teaching Them How To Feel, Michael Benjamin Wooten

All Dissertations

Continuum robots offer unique potential benefits for environmental exploration, notably in using their maneuverability to navigate congested environments. In this dissertation, we show how circumnutation, a motion strategy, commonly employed by plants, can be implemented, and usefully exploited, with continuum robots. We discuss how the kinematics of circumnutation, which combines local backbone growth with periodic backbone bending, can be created using extensible continuum robot hardware. The underlying kinematics are generated by adapting kinematic models of plant growth. We illustrate the effectiveness of that approach with experimental results with a tendril robot exploring a congested environment. However, significant challenges remain in …

Full-Body Biomechanical Characterization Of Children With Hypermobile Ehlers-Danlos Syndrome During Gait And Activities Of Daily Living, Anahita Alahmoradiqashqai

Theses and Dissertations

Hypermobile Ehlers-Danlos syndrome (hEDS) is an inherited connective tissue disorder, often under-diagnosed, and presenting with frequent chronic pain and severe musculoskeletal symptoms that can drastically reduce the quality of life during one’s life span. While there are limited quantitative approaches in the literature on adult movements, the biomechanics of movements during activities of daily living (ADLs) in children have not been investigated comprehensively. Therefore, the primary purpose of this dissertation was to characterize the biomechanics of the musculoskeletal system and investigate the biomechanics of hEDS by quantifying joint dynamics and muscle activations during ADLs and gait in the pediatric population. …

Concurrent Identification, Characterization, And Reconstruction Of Protein Structure And Mixed-Mode Dynamics From Rdc Data Using Redcraft, Hanin Rafiq Omar

Theses and Dissertations

A complete understanding of the structure-function relationship of proteins requires an analysis of their dynamic behaviors and the static structure. However, all current approaches to studying dynamics in proteins have their shortcomings. A conceptually attractive and alternative approach simultaneously characterizes a protein's structure and its intrinsic dynamics⁠. Ideally, such an approach could solely rely on RDC data-carrying both structural and dynamical information. The major bottleneck in utilizing RDC data in recent years has been attributed to a lack of RDC analysis tools capable of extracting the pertinent information embedded within this complex data source.

Here we present a comprehensive strategy …

Dynamic Analysis Of Cubesat Impact On Lunar Surface, Dalton C. Korczyk

Doctoral Dissertations and Master's Theses

EagleCam is a pico-satellite (CubeSat) with dimensions of 100 x 100 x 150 mm3 that is going to the moon as a payload of the Intuitive Machines Nova-C lunar lander. The CubeSat’s purpose is to record the lunar landing from a 3rd person view. Unlike other CubeSats, EagleCam is designed to impact the lunar surface and there is no history to build off of. Specifically, EagleCam will need to survive a 30 m drop onto the lunar surface with all internal components fully operational post impact. This thesis is focused on the analytical, numerical, and experimental methods for determining the …

Dynamic Maneuvers For Satellite On-Orbit Servicing Utilizing Novel Continuum Robotics: Development & Experimentation, Nathan Dalton

Masters Theses

Robotic on-orbit servicing is a developing technology that seeks to increase the longevity and repairability of faulty or aging resident space objects. In this research, the development of a flexible continuum manipulator for a small satellite system that performs low-complexity on-orbit servicing or debris removal is presented. Derivations of manipulator kinematics are described in detail, a non-linear control scheme has been developed, and the accuracy and servicing applications for the prototype are evaluated and discussed. The manipulator has been tested on an air-bearing dynamics simulator, and the results are extensively analyzed. System recommendations and future work suggestions are presented.

Characteristic Of The Dynamics Of Disorder In Crystalline And Amorphous Materials, Amir Behbahanian

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This work provides the evidence to apply simulation methods that are applicable to systems with structural randomness to simulate crystalline materials at high temperatures. My work not only open the avenue to expand the simulation capability of materials but also provides insight to the physics of vibrations of atoms under different temperature and for different types of materials. I have also evaluated the reliability of Molecular Dynamics simulations at the frequency level and found that theses types of simulations, despite the previous belief, are reliable at low temperatures but up to a measurable frequency. In addition, the result of my …

Data-Driven Learning For Robot Physical Intelligence, Leidi Zhao

Dissertations

The physical intelligence, which emphasizes physical capabilities such as dexterous manipulation and dynamic mobility, is essential for robots to physically coexist with humans. Much research on robot physical intelligence has achieved success on hyper robot motor capabilities, but mostly through heavily case-specific engineering. Meanwhile, in terms of robot acquiring skills in a ubiquitous manner, robot learning from human demonstration (LfD) has achieved great progress, but still has limitations handling dynamic skills and compound actions. In this dissertation, a composite learning scheme which goes beyond LfD and integrates robot learning from human definition, demonstration, and evaluation is proposed. This method tackles …

Nonlinear Model Development And Validation For Ball And Plate Control System, Zachary Richter

Master's Theses

Ball and plate balancing control systems are commonly studied due to the complex dynamics associated with the instability of the system in open-loop. For simplicity, mathematical models describing the ball and plate dynamics are often linearized and the effects of complex motion are assumed to be negligible. These assumptions are rarely backed with evidence or explanations validating the simplified form of the dynamical equations of motion. This thesis focuses on developing a nonlinear model that more accurately defines the dynamics of the system, in order to quantify the error of linear and nonlinear models when compared to a Simscape physical …

Displacement-Based Dynamometer For Milling Force Measurement, Michael F. Gomez

Doctoral Dissertations

This project will study the design and testing of a low-cost dynamometer for milling dynamic force measurement. The monolithic design is based on constrained-motion/flexure-based kinematics, where force is inferred from displacement measured using a low-cost optical interrupter (i.e., a knife edge that partially interrupts the light beam in an emitter-detector pair). The time-dependent displacement of the dynamometer’s moving platform caused by the milling force is converted to the frequency domain, multiplied by the inverse of the dynamometer’s ideally single degree of freedom (SDOF) frequency response function (FRF), and converted back into the time-domain to obtain the time-dependent cutting force. The …

Numerical Simulation Of Losses In Four-Way Pipe Junctions, Simon Barth

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

To design pipelines, engineers need to know how much energy the fluid in the pipe has at different locations in the pipe network. The energy the fluid has comes in the form of pressure, velocity, and elevation. As fluid travels through a pipe, it loses energy for many different reasons. Some of those reasons include friction between the fluid and the pipe wall, shear forces within the fluid, changes in flow direction, changes in elevation, or various pipe fittings like elbows, tee’s, valves, reducers, and expanders. Many of the causes of energy loss are well researched. One cause of energy …

A Single-Stage Passive Vibration Isolation System For Scanning Tunneling Microscopy, Toan T. Le

Master's Theses

Scanning Tunneling Microscopy (STM) uses quantum tunneling effect to study the surfaces of materials on an atomic scale. Since the probe of the microscope is on the order of nanometers away from the surface, the device is prone to noises due to vibrations from the surroundings. To minimize the random noises and floor vibrations, passive vibration isolation is a commonly used technique due to its low cost and simpler design compared to active vibration isolation, especially when the entire vibration isolation system (VIS) stays inside an Ultra High Vacuum (UHV) environment. This research aims to analyze and build a single-stage …

Dynamic Neuromechanical Sets For Locomotion, Aravind Sundararajan

Doctoral Dissertations

Most biological systems employ multiple redundant actuators, which is a complicated problem of controls and analysis. Unless assumptions about how the brain and body work together, and assumptions about how the body prioritizes tasks are applied, it is not possible to find the actuator controls. The purpose of this research is to develop computational tools for the analysis of arbitrary musculoskeletal models that employ redundant actuators. Instead of relying primarily on optimization frameworks and numerical methods or task prioritization schemes used typically in biomechanics to find a singular solution for actuator controls, tools for feasible sets analysis are instead developed …

Relative Attitude Dynamics And Control Of Spacecraft Using Electrostatic Torque, John Galjanic

Doctoral Dissertations and Master's Theses

Recent years have seen an increased interest in spacecraft formation flying, with many applications requiring that the members of these formations maintain specific relative attitude configurations. One low-cost method that has been considered to accomplish this is the use of electrostatic torques, which are generated by charging the surfaces of involved spacecraft to allow interaction without physical contact. The research presented in this thesis analyzes a pair of cylindrical-bodied spacecraft operating in deep space. Specifically, the suitability of using electrostatic torques as an actuator to synchronize the two spacecraft's attitude responses is under consideration. The study considers a simplified case, …

The Use And Explanation Of The Phase Angle In Forced Vibration Testing, Nicholas R. Slavin, Ryan D. Thornton

Architectural Engineering

Forced vibration testing is a tool used to characterize a structure’s dynamic properties. When subjecting a structure to a forced harmonic load, the results help define the structure’s fundamental frequencies and dominant mode shapes. However, when conducting testing, it is difficult to determine the contributions of each mode to the response at a given location in the structure. The recorded response from a forced vibration test is a combination of unknown modal constituents. Excitation may not result in the pure, single mode response that the experimenter desires, but may instead result in a combination of modal responses that obscure the …

Mechani-Kits Senior Design Project, Jake Utley, Sophie Carson, Vincent Seguin

Mechanical Engineering

Studies suggest that when designed and executed well, hands-on activities can enhance student understanding of key mechanics concepts. Current products are expensive and typically not designed to meet a variety of learning objectives. Through the Mechanics of Inclusion and Inclusivity in Mechanics grant, the Cal Poly Physics and Engineering Departments are seeking to incorporate new hands-on activities into their courses. Our team has designed three inexpensive ”MechaniKits” to be used in physics, statics and dynamics courses [1]. This Final Design Review outlines our findings, objectives, and final designs for this project. It also explains our manufacturing and design verification plans. …

Dynamic And Control Of Air-Bearing Spacecraft Simulator, Jacob Joseph Korczyk

Doctoral Dissertations and Master's Theses

An air bearing is being designed as a spacecraft rotational motion simulator, featuring the Sawyer Robot and its control box. The objective is to maneuver the robot as desired, performing operations specific to on-orbit servicing operations while maintaining stability of the system. Before the control can be designed, the dynamics of the platform and the robot must be modeled. The dynamics of the robot can be derived utilizing a Newton-Euler recursive approach. By beginning with a simple pendulum, then adding links (degrees of freedom) to more closely resemble the Sawyer arm, the equations of motion for the robot can be …

Brian Valdez - Dynamics And Control Of A 3-Dof Manipulator With Deep Learning Feedback, Brian Orlando Valdez

Open Access Theses & Dissertations

With the ever-increasing demands in the space domain and accessibility to low-cost small satellite platforms for educational and scientific projects, efforts are being made in various technology capacities including robotics and artificial intelligence in microgravity. The MIRO Center for Space Exploration and Technology Research (cSETR) prepares the development of their second nanosatellite to launch to space and it is with that opportunity that a 3-DOF robotic arm is in development to be one of the payloads in the nanosatellite. Analyses, hardware implementation, and testing demonstrate a potential positive outcome from including the payload in the nanosatellite and a deep learning …

Model-Based Network Reconstruction From Cascade Dynamics, Katherine Irena Chwistek

Graduate Research Theses & Dissertations

Network representation provides a natural framework for the study of real world complex systems. From social networks and animal groups to interneuronal communications and power grid systems, complex patterns of interaction can be captured and modeled using networks in a simple mathematical form. In many cases, however, a faithful network representation of the system is not readily available. For this reason, network reconstruction has become a growing topic of interest in recent years, the goal of which is to discover the hidden interaction patterns among individuals by fitting input-output data from multiple experiments to candidate network topologies.

During a cascade, …