Acoustics, Dynamics, and Controls Commons^™

External Direct Sum Invariant Subspace And Decomposition Of Coupled Differential-Difference Equations, Keqin Gu, Huan Phan-Van

SIUE Faculty Research, Scholarship, and Creative Activity

This article discusses the invariant subspaces that are restricted to be external direct sums. Some existence conditions are presented that facilitate finding such invariant subspaces. This problem is related to the decomposition of coupled differential-difference equations, leading to the possibility of lowering the dimensions of coupled differential-difference equations. As has been well documented, lowering the dimension of coupled differential-difference equations can drastically reduce the computational time needed in stability analysis when a complete quadratic Lyapunov-Krasovskii functional is used. Most known ad hoc methods of reducing the order are special cases of this formulation.

Covenant Persuasion Lead To Constitutionalism – Neither Was Invented, Joseph Livni

Helm's School of Government Conference

Constitutionalism is a conviction shared by people that a government must act in compliance with a dominant charter. So is covenantal persuasion. The covenant reflects statutes and traditions etched in a living covenantal practice. The practice cannot exist without the persuasion and the persuasion cannot exist without the practice. Elazar was one of the most prolific scholars of the covenantal model. There is one point were the paper diverges from Elazar. The paper discusses a mathematical model and other studies of the covenant practice demonstrating that such a practice involves a multitude of simultaneous vital conditions. That led to the …

Cable Decoupling And Cable-Based Stiffening Of Continuum Robots, Parsa Molaei

LSU Master's Theses

Cable-driven continuum robots, which are robots with a continuously flexible backbone and no identifiable joints that are actuated by cables, have shown great potential for many applications in unstructured, uncertain environments. However, the standard design for a cable-driven continuum robot segment, which bends a continuous backbone along a circular arc, has many compliant modes of deformation which are uncontrolled, and which may result in buckling or other undesirable behaviors if not ameliorated. In this study, a detailed approach for using additional cables to selectively stiffen planar cable-driven robots without substantial coupling to the actuating cables is investigated. A mechanics-based model …

Estimation Of The Response, Power Spectra, And Whirling Patterns Generated From Mud Circulating Along The Annulus During Drilling Procedures: An Alternative Mathematical Representation Via Finite Element Modelling, Eleazar Marquez

Mechanical Engineering Faculty Publications and Presentations

In this study, an alternative mathematical representation of a drill-string is proposed to provide an alternative assessment on BHA dynamic alterations. Lateral vibrations remain the focal point of drill-string breakdowns given their high frequency characterization and ability to deviate perforation trajectories from the subsurface target. In this paper, the proposed model consists of an anisotropic rotor subjected to distinct RPMs, an axial force, and a bidirectional harmonic excitation with specified amplitude and assorted duration to simulate annulus motion generated from the mud fluid. In this regard, Euler-Bernoulli beam theory was adopted to establish a complete MDOF mathematical expression and thus …

A Probabilistic Analysis In Vibration-Assisted Drilling To Measure Dynamic Behavior During Drilling And Understand Risk Factors, Eleazar Marquez, Samuel Garcia

Mechanical Engineering Faculty Publications and Presentations

In this paper, a mathematical representation is proposed to further understand the dynamic behavior and risk factors associated with vibration-assisted drilling (VAD) technology. The proposed Timoshenko beam model, which characterizes VAD technology, consists of two passive, counter-rotating coaxial rotors operating simultaneously, subjected to a stochastic excitation. In this regard, a finite element technique was incorporated to determine the physical parameters of the governing equation of motion, where the shear and rotary effects, as well as the gyroscopic couples generated perpendicular to the axis of rotation, were accounted for. Further, the relative velocity between the coaxial rotors was accounted in the …

Development Of An Improved Mathematical Representation Which Captures The Nonlinear Dynamic Behavior Of A Drill-String Assembly, Eleazar Marquez

Mechanical Engineering Faculty Publications and Presentations

In this study, an improved mathematical representation of a drill-string assembly is developed to provide an alternative assessment on vibration irregularities proliferating downhole due to bit-rock interference. Lateral vibrations receive particular attention due to their high frequency content which alter the dynamic response of the drill-string, instigate casing damage, and impede optimal penetration rates. The response of the drill-string is captured by synthesizing compatible stationary bit excitations, via an auto-regressive digital filter, and implementing Monte Carlo simulation, while the power spectral density function is approximated to elucidate the dynamic characteristics during drilling. Formulating adequate physical parameters for the equation of …

Alternative Method For Low Frequency Impact Sound Measurement For Building Field Tests, Sunit Girdhar

Dissertations, Master's Theses and Master's Reports

What do high heels, dog nails, and dragging furniture have in common? They are all frequent sources of noise pollution and annoyance in multi-story buildings. Building codes exist to control and mitigate such noise, but these codes are outdated and fail to protect the residents against noise annoyance. Footstep noise is still the number one cause of complaints among the residents. The impact performance of floor-ceiling assemblies is characterized using a single-number rating called the Impact Sound Rating (ISR). A standard tapping machine is used in pre-defined locations on the floor and the radiated Sound Pressure Level (SPL) is measured …

Mechanical Energy Harvester For Powering Rfid Systems Components: Modeling, Analysis, Optimization And Design, Alireza Babaei

Theses and Dissertations--Mechanical Engineering

Finding alternative power sources has been an important topic of study worldwide. It is vital to find substitutes for finite fossil fuels. Such substitutes may be termed renewable energy sources and infinite supplies. Such limitless sources are derived from ambient energy like wind energy, solar energy, sea waves energy; on the other hand, smart cities megaprojects have been receiving enormous amounts of funding to transition our lives into smart lives. Smart cities heavily rely on smart devices and electronics, which utilize small amounts of energy to run. Using batteries as the power source for such smart devices imposes environmental and …

Optimal Path Planning For Aerial Robots Using Genetic Algorithm, Anna Puigvert I Juan

Graduate Theses, Dissertations, and Problem Reports

This thesis presents a path optimization solution for a robot in two different constrained 3-dimensional (3D) environments. The robot is required to travel from its current position to a goal position following minimum cost paths (optimal paths). The first environment has 3D obstacles that interfere with the robot’s path. The path cost for this environment accounts for the minimum distance traveled by the robot from the start to the goal position while avoiding obstacles. The second environment is the atmosphere of Venus, specifically a flyable region of this atmosphere with characteristics similar to Earth’s. This environment has strong westward winds …

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, …

Novel Hitch Cargo Cart, Cesilio Sanchez Ramirez, Lance Haidet, Richard Lontoc, Tyler Selinka

Mechanical Engineering

This document presents the engineering design process used to develop, manufacture, and test a new and improved iteration of a hitch cart prototype. This process was performed by a team of four mechanical engineering seniors as part of California Polytechnic State University, San Luis Obispo’s senior design pathway. The goal of this project was to develop a sturdy and reliable iteration of our sponsor’s hitch cart prototype, that integrated the functionality of a vehicle hitch cargo platform and that of a height adjustable cargo cart into a single streamlined and easy to use product. This design could be used by …

Novelty Ice Cream Assembly Prototype, Mason Sylvester, Logan Williamson, Alvaro Martinez, Adin Gilman-Cohen

Mechanical Engineering

Cool Beans USA is a novelty ice cream startup company founded by Keith Zachow. In the winter of 2022, our team began working with Mr. Zachow to develop a machine to automate parts of the production process for his product. This product consists of two hemispherical ice-cream cone shell halves filled with soft serve ice cream and pressed together. The assembled pods are around the size and shape of a small walnut and are intended to be sold in stores as a frozen finger food. At the time of project inception, this product was in its early stages and was …

Multiple Heat Exchanger Cooling System For Automotive Applications – Design, Mathematical Modeling, And Experimental Observations, Zaker Syed

All Dissertations

The design of the automotive cooling systems has slowly evolved from engine-driven mechanical to computer-controlled electro-mechanical components. With the addition of computer-controlled variable speed actuators, cooling system architectures have been updated to maximize performance and efficiency. By switching from one large radiator to multiple smaller radiators with individual flow control valves, the heat rejection requirements may be precisely adjusted. The combination of computer regulated thermal management system should reduce power consumption while satisfying temperature control objectives. This research focuses on developing and analyzing a multi-radiator system architecture for implementation in ground transportation applications. The premise is to use a single …

Infusing Kirigami Principles Into Design Of Mechanical Properties, Hesameddin Khosravi

All Dissertations

The emergence of mechanical metamaterials — which derive their properties primarily from the underlying architecture rather than the constituent material — has unleashed a new era of material design and functionalities. To fully materialize the promising potentials of metamaterials, it is crucial to develop versatile, scalable, and easy-to-fabricate methods that can both generate and tailor the underlying periodic architecture. To this end, we propose the use of kirigami — a popular recreational art of cutting and manipulating paper — as a platform to create periodicity and super-stretchability. Kirigami has become a design and fabrication framework for constructing metamaterials, robotic tools, …

Baby Soothing Device, Grace Kalene Mekrut, Matteo Gozzini, Miles Angel Ibarra, Christian Joel Roberts

Mechanical Engineering

This document is the official final design review for the Baby Soothing Device. This product is intended to help families sleep throughout the night by allowing a baby to be soothed back to sleep without constant and direct parental interaction. It is maintained by Mechanical Engineering students at California Polytechnic State University, San Luis Obispo for Dustin Yoder, the project sponsor. The purpose of this document is to present the design process from ideation to finished design in great enough detail that its manufacturing procedure may be replicated if desired. This document further explains all the research, testing, and benchmarks …

Multiple Objective Function Optimization And Trade Space Analysis, Yifan Xu

All Theses

Optimization can assist in obtaining the best possible solution to a design problem by varying related variables under given constraints. It can be applied in many practical applications, including engineering, during the design process. The design time can be further reduced by the application of automated optimization methods. Since the required resource and desired benefit can be translated to a function of variables, optimization can be viewed as the process of finding the variable values to reach the function maxima or minima. A Multiple Objective Optimization (MOO) problem is when there is more than one desired function that needs to …

Koopman Operator Theory And The Applied Perspective Of Modern Data-Driven Systems, Alex Krolicki

All Theses

Recent theoretical developments in dynamical systems and machine learning have allowed researchers to re-evaluate how dynamical systems are modeled and controlled. In this thesis, Koopman operator theory is used to model dynamical systems and obtain optimal control solutions for nonlinear systems using sampled system data. The Koopman operator is obtained using data generated from a real physical system or from an analytical model which describes the physical system under nominal conditions. One of the critical advantages of the Koopman operator is that the response of the nonlinear system can be obtained from an equivalent infinite dimensional linear system. This is …

Modeling, Control And Estimation Of Reconfigurable Cable Driven Parallel Robots, Adhiti Raman Thothathri

All Dissertations

The motivation for this thesis was to develop a cable-driven parallel robot (CDPR) as part of a two-part robotic device for concrete 3D printing. This research addresses specific research questions in this domain, chiefly, to present advantages offered by the addition of kinematic redundancies to CDPRs. Due to the natural actuation redundancy present in a fully constrained CDPR, the addition of internal mobility offers complex challenges in modeling and control that are not often encountered in literature.

This work presents a systematic analysis of modeling such kinematic redundancies through the application of reciprocal screw theory (RST) and Lie algebra while …

Performance Comparison Of Several Control Algorithms For Tracking Control Of Pantograph Mechanism, Laylaa Mahmoud Eng, Mohamed Shamseldin Dr, Mohamed Sallam Dr, Abdelghany Mohamed Prof

Future Engineering Journal

A sort of parallel manipulator known as a pantograph robot mechanism was created primarily for industrial requests that required high precision and satisfied speed. While tracking a chosen trajectory profile requires a powerful controller. Because it has four active robot links and one robot passive link in place of just two links like the open chain does, it can carry more loads than the open chain robot mechanism while maintaining accuracy and stability. The calculated model for a closed chain pantograph robot mechanism presented in this paper takes into account the boundary conditions. For the purpose of simulating the dynamics …

Multi-Robot Symbolic Task And Motion Planning Leveraging Human Trust Models: Theory And Applications, Huanfei Zheng

All Dissertations

Multi-robot systems (MRS) can accomplish more complex tasks with two or more robots and have produced a broad set of applications. The presence of a human operator in an MRS can guarantee the safety of the task performing, but the human operators can be subject to heavier stress and cognitive workload in collaboration with the MRS than the single robot. It is significant for the MRS to have the provable correct task and motion planning solution for a complex task. That can reduce the human workload during supervising the task and improve the reliability of human-MRS collaboration. This dissertation relies …