Class Projects
What is in this collection?
I completed a number of class projects, many of which were team efforts. I describe some of these projects with pictures on this page. They are presented in reverse chronological order to show progression.
Although academic credit was received for the orrery, it was self-initiated and self-directed rather than a class-assigned project. Therefore, the orrery has its own page. I also initiated Open Hardware Makerspace which received funding and university recognition, but I did not receive academic credit for it.
Automated Systems Engineering
About the course: Although it also covered other topics, this course was my primary introduction to programmable logic controllers (PLCs) and writing CNC g-code. Individual PLC exercises generally involved controlling timing of traffic/stoplights.
About the project: The final, six-student team project was to develop a “prototype hardware system for automating the sequence of operations” to include a PLC, inputs, sensors, actuators, and outputs. We decided to prototype a vending machine: a sensor would detect the coin insertion, the user would select the product they wanted, pneumatic actuators would dispense the product, and feedback would be provided with lights. My primary contribution was the physical system, sensors, and actuators.
Engineering Design Optimization
About the course: This course provided a formal approach to nonlinear optimization problems and a survey of numerical optimization algorithms. I implemented a variety of optimization methods (univariate and multivariate, nonheuristic and heuristic) in MATLAB, including genetic algorithms.
About the project: For the final project, our three-student team considered truss designs; the load case had a point load in the middle of the span. We previously wrote MATLAB finite element analysis code in MAE 533 which could be used for problems like this, but our team wanted to demonstrate optimization could also be done for more complex finite element models. Therefore, we used ANSYS as a “black box” function that returned outputs (stress values) for our inputs (designs). I used MATLAB to generate text scripts for ANSYS Mechanical ADPL, including node locations and element connectivity, and to then run them using the Linux command line. ANSYS returned its deflection and stress results in text files, which were iteratively used in MATLAB to make design improvements. The below animation was generated in MATLAB to visually represent the changes to the ANSYS text scripts.
Design of Electromechanical Systems
About the course: This course provided “theory and practical tools for the design of electric machines (standard motors, linear actuators, magnetic bearings, LVDTs, etc)” with an emphasis on modeling, analysis and design.
About the project: For a hands-on project, our three-student team built a perpetual pendulum; energizing a coil in its base kept it moving. FEMM was used for multiple modeling tasks during the course; the model for this project is shown below with the pendulum sweeping through a range of angles. Unfortunately, the colorscale is not constant between frames. My primary contribution to the project was creating a data acquisition system for live magnetic field readings in the coil at the base using an Arduino and MATLAB.
Senior Design
All NC State bachelor-degree mechanical engineering students take a design class each semester of their senior year. We were assigned three design projects for the fall semester and one design/fabrication project in the spring semester.
Spring Semester: Vehicle Suspension Redesign
EcoCAR2 was an intercollegiate competition sponsored by General Motors and the Department of Energy to improve the fuel efficiency and emissions of a 2013 Chevrolet Malibu. In support of NC State University’s EcoCAR2 team, our team of five students analyzed and made simple modifications to a vehicle suspension system to compensate for the addition of the new 550 pound battery pack in the rear of the vehicle. (The battery pack was installed as a step in converting the car from gas to hybrid.) I wrote several sections of the final (106 page) report and checked a teammate’s analysis for accuracy. An abridged version of our final report is provided below.
Fall Semester
About the course: This portion of senior design had no lab component. Instead, students analyzed a series of open-ended design problems and prepared formal reports communicating the design process and conclusions.
About the project: The last of the three fall semester projects was a garage door assist system. Our team consisting of five students analyzed the door’s movement to determine the force required to lift a garage door and selected components (chain/sprocket, torsion spring, and motor) which could be used to build our design.
The magnitude of the force required to maintain the garage door in a quasi-static equilibrium undulates as each door panel transitions between the vertical, curved, and horizontal sections of the track. The graph shows the selected spring prescribed by our design analysis allows the garage door to remain in both the open and stored positions while also (when compared to a reference design) requiring less force to move it.
Controls: Inverted Pendulum Stabilization
About the courses: MAE 435 and MAE 469 were controls classes; one was primarily lecture-oriented while the other was a lab class. The teaching focused on feedback control of linear systems, including proportional-integral-derivative (PID) control.
About the project: A projects assigned to our team of four was to implement a PID controller in MATLAB’s Simulink to stabilize and control an inverted pendulum (a system in which the axis of rotation exists below the center of the mass of the pendulum). The system we had was single-input (pendulum angle) and single-output (a motor for pivot translation). The project definition prescribed a maximum starting angle of 20° from vertical. Not only could the controller stabilize the pendulum from that offset, it could also track a sine wave with the pendulum angle and handle changes to the pendulum length. In the below video, you can observe the controller keep the pendulum vertical.
Modern Manufacturing Processes
About the course: This special-topics seminar was an introduction into an array (subtractive, additive, forming, hybrid, and joining) of modern manufacturing processes through both lectures and hands-on labs. This class was the first time I used a lathe, mill, and 3d printer.
About the project: This was 1 of 5 labs/projects in the course. During this particular project, I collaborated with two students, each at a different university in a different state (NIU and TAMU). We were given a month to choose a project based on our schools’ combined manufacturing capabilities, use different manufacturing processes to create parts at different locations, and finally ship and assemble the components. This was an exercise in remote collaboration, including dealing with different CAD packages, and intended to reflect how components are frequently manufactured in different locations yet must still assemble successfully.
Introduction to Engineering
About the course: This is a requirement for all first-year engineering students, intended to provide an introduction to engineering as a discipline and profession. Practicing the engineering design process was done through an interdisciplinary team project.
About the project: Our four-student team made an arcade game in which the player attempted to use the plunger to launch a steel ball into the holes (possibly even on the spinning disks).
