introduction - sean reidyseanmreidy.com/uploads/seanreidyportfolio.pdfthen used scripted algorithms...

SEAN M. REIDY

1024 Conception Drive • Lompoc, CA 93436 240-478-4734 • [email protected] • http://seanmreidy.com

INTRODUCTION

My name is Sean Reidy. I'm 26 years old and grew up in

Montgomery County, Maryland and am currently a Launch

Engineer for SpaceX in Southern California. I'm working to

launch things, and eventually humans, into space. My current

responsibilities include launch operations and automation out

of Vandenberg AFB and Cape Canaveral AFS, as well as

automating the launch integration process.

I earned my bachelors of science in Mechanical Engineering

from the University of Pennsylvania in 2015 with a minor in

Computer Science. I hold a deep interest in mechanical

systems and robotics, inspired by my work in Penn's General

Robotics, Automation, Sensing, and Perception (GRASP)

laboratory. There I used and even modified 3D printers to

explore new manufacturing possibilities. My involvement in

Penn's graduate-level Design of Mechatronic Systems class

solidified my interest in robotics. I want to leverage

mechanical design, electronics design and computer science to

work with complicated systems.

In summer 2014, as an intern at The Boeing Company, I

worked in the Scripted Process Engineering team where I

wrote code in Python to automate the manufacturing process

for composite material panels used in the construction of new

Boeing 787 and 777X aircraft.

At Penn I served as a teaching assistant for the Introduction to

Computer Science class for three years, where I held weekly

recitation sessions and office hours to help students learn

programming. I also served as President of the Penn chapter

of the American Society of Mechanical Engineers, and was

actively involved in Theta Tau Professional Engineering

Fraternity and Alpha Chi Rho Fraternity.

I have made an effort to diversify my skills across the

mechanical engineering and computer science disciplines. I

have refined my skills in mechanical design by learning and

mastering the SolidWorks application on my project work

over the last three years. I have worked with MATLAB for

data analysis and expanded my coding skills by developing

expertise across a variety of programming languages including

C, C++, Java, Python, and PHP. I also designed electronic

circuitry and hand-soldered circuit boards for all my projects.

The following pages present a sampling of project work that

showcases a broad spectrum of the skills and experience I

have developed at Penn, not so much a summary of my

current professional work, which is mostly ITAR protected. If

you would like to see more of my projects, please visit my

website at http://seanmreidy.com.

Me on top of Mount Si, around 30 miles

from Seattle, WA.

SpaceX (2015-Present)

The Boeing Company (Summer 2014)

General Robotics, Automation, Sensing

and Perception Laboratory (2013-2014)

National Institute of Standards and

Technology (Summer 2012)

http://seanmreidy.com/

SEAN M. REIDY


BREAZE

MEAM 446 – Mechanical Engineering Senior Design

September 2014 – April 2015

Collaborators: Shelby Bierig, Lars-Patrik Roeller, Noah Frick

OVERVIEW

Breaze is a portable, autonomous solution to oxygen tank

transport for the purpose of supplemental oxygen therapy. A

variety of ailments require continuous oxygen supply such as

chronic obstructive pulmonary disease, late-stage heart failure,

cystic fibrosis, and pneumonia. As elderly patients travel

within the hospital, they often require nursing assistance to

carry their oxygen tanks which discourages them from

maintaining their physical therapy.

TECHNICAL APPROACHES

Breaze is a robotic retrofit for oxygen tanks which can follow

patients around in a hospital setting, eliminating the need for

manual transport or nursing assistance. The device is powered

by DC motors and can change directions with the patient, as

well as avoid obstacles in its path. By implementing robotic

control and path-planning algorithms, Breaze will track

patients and maintain a proper distance, making mobility more

feasible and less of a burden. To meet the demands of an

aging population, Breaze increases the quality of life for

patients by promoting mobility and incentivizing consistent

oxygen therapy.

The user wears a "beacon" belt pack, with one ultrasonic

Parallax transmitter and an RF receiver to sync the time

signal. The vehicle contains three spaced ultrasonic Parallax

sensors which pick up the signal from the beacon. The vehicle

transmits a packet via RF to the beacon, and proceeds to wait

for the signal from the ultrasonic transmitter. Upon recording

the time taken to receive the signal from the beacon, the

vehicle triangulates the relative position (distance and

orientation) from the user. Because we have three holonomic

constraints, we can determing planar x-y relative position, so

the height of the user is irrelevant.

After gathering location information, the control algorithm

uses a PD-based controller to correct the vehicle to "zero-in"

on the user, as well as maintain a 1-meter distance from the

user, and is capable of smooth correction up to 2 m/s.

OUTCOME

Breaze was successfully able to track and follow a human

patient with smooth control implementation.

General overview of system.

Final Breaze product.

Closed-form triangulation.

SEAN M. REIDY


ROBOCKEY 2013

MEAM 510 – Design of Mechatronic Systems

November – December, 2013

Collaborators: Klyde Breitton, Nick Labarbera

OVERVIEW

This is Robockey, the final project for MEAM 510. In

summary, Robockey is a 3v3 autonomous robot hockey

tournament. In 2013, there were close to 30 teams competing

in the tournament. Each robot used 4 LED “stars” above a

hockey rink to determine location and orientation data, and

then used scripted algorithms to find a puck, evade enemy

robots, and shoot the puck to their respective goal.

Our three robots had different functions – Robot 1 served only

to find the puck and score, Robot 2 rushed forward and

blocked other robots from Robot 1’s path, and Robot 3 was a

defender who stayed near our goal to attempt saves.


Each of our robots was powered by two 600mAh 9V batteries

- one for motor power, and one for logic. The robots are

controlled by an AVR microprocessor, and localization is

accomplished with the help of the Nintendo Wii sensor. All of

the manufacturing, electronics, and code were completely

original work by our team.

Seven IR phototransistors spaced around the bottom of the

bots served to detect a custom IR-LED puck. The robots are

designed to turn at different degrees/speeds depending on

which phototransistor has the highest value; they move slower

and turn tighter when the phototransistors near the back are at

a maximum, and move faster/turn very slightly when the ones

near the front are at a maximum. Proportional-Integral-

Derivative (PID) control is implemented to ensure smooth

movement.

All electronics were designed and manufactured by our team.

The exterior of the robots were composed primarily of acrylic

plastic and were designed using SolidWorks and

manufactured via laser cutting.

OUTCOME

Our team fared well in the round-robin portion of the

tournament – after 5 games, our team was undefeated.

Overall, we finished in the top third of the class, and felt

satisfied with our end product.

Robot 1 after initial assembly.

SolidWorks final rendering of Robot 3.

Robots 1 and 3 after the tournament.

SolidWorks Design of Robot 2.

SEAN M. REIDY


BUNGEE CORD DESIGN

MEAM 348 – Mechanical Engineering Design Laboratory

January, 2014

Collaborators: Lars-Patrik Roeller, Robert Ritchie

OVERVIEW

In this lab, our team was tasked with designing a model for

bungee cords made of rubber bands, based off force-

displacement testing, energy methods, and statistical analysis.

Teams were given the mass of the “jumper” (in this case, a

0.5-1 kg mass), and height of the jump just 30 minutes before

a demonstration, and we needed to determine the cord

characteristics (how many rubber bands and series and how

many in parallel) and construct the cord in that time. Teams

needed to maximize free-fall length for the jumper, as well as

keep the force below 5 G’s. Our team constructed a script in

MATLAB, based on a force-displacement function that was

determined by stretch-testing. The output of our script

provided the number of rubber bands (in series and parallel)

which would provide the ideal bungee jumping conditions.


To determine the relationship between the stretching length of

a rubber band and the resultant force it exerts elastically, we

used a MTS force sensor on different combinations of

configurations – one in series, two in series, two in parallel,

etc. We then normalized this data to make displacement in

terms of percentage of the unstretched length of the bands, and

divided the total force by the number of parallel chains. The

force-displacement curves then collapsed into one curve; this

way, given a set of rubber bands with x bands in series and y

bands in parallel, we would be able to expand the force-

displacement curve to fit the configuration.

Our team’s MATLAB script to calculate the bungee cord

configuration took as input (a) the mass of the “jumper” and

(b) the height of the jump. Using our force-displacement

function, we determined an optimal strain for the rubber band

chain, and used energy methods to calculate the final

configuration.

OUTCOME

The final parameters on test day were a 0.555 kg jumper and a

42-foot drop. Our MATLAB script outputted a configuration

of 1-1/6 bands in parallel (in this case, doubling up every sixth

band) and 32 in series. Our team was successful in the

demonstration, achieving a force of 3.8 G’s and having the

jumper stop less than 3 feet above the ground.

Rubber band linking configuration.

Force vs. Displacement graph of

different rubber band configurations.

Normalized Force vs. Displacement.

Acceleration G-force data over time.

SEAN M. REIDY


FORCED CONVECTION HEAT SINK DESIGN

MEAM 348 – Mechanical Engineering Design Laboratory

March, 2014

Collaborators: Kris Li, David Tompkins

OVERVIEW

In this lab, our team was to design a heat sink for a metal

plate. This metal plate would be heated by an electric current

and be placed in a wind tunnel to induce forced convection.

Our task was to dissipate heat on the plate for the largest area

possible. Evaluations were favorable for slow wind speeds,

high electrical power, and high heat dissipation. Temperature

readings were taken through a thermal imager.

This lab served to test our knowledge of heat transfer, to

complement a course my mechanical engineering class was

taking at the time, Heat and Mass Transfer.


Our team’s plan was to create as much surface area as possible

for our heat sink to maximize convection heat transfer with

the surrounding air. We chose to use thin sheets of aluminum

alloy with a high thermal conductivity to maximize area and

minimize mass. To keep under the mass limit of 150 g, we

would not have our heat sink span the entire area of the plate,

but put it near the back where the effects of the forced

convection from the wind tunnel would have the least effect.

Our design implemented a fan-like fin geometry. These fins

were spaced out in order to provide maximum “breathing

room” for the sink to increase fin efficiency.

To analyze our design, we ran a test in the wind tunnel. After

10 minutes (where the plate would reach steady state

temperature distribution), we used a thermal reader to take a

temperature reading of the plate. We used a MATLAB script

to read the image produced by the reader to determine the

success of heat dissipation.

OUTCOME

The final version of the heat sink yielded a 60% successful

area of heat dissipation, under conditions of 70% maximum

power and only 20% of wind power. This resulted in a

favorable evaluation by the teaching staff. Out of a field of 20

teams, our team placed third in our overall score.

SolidWorks rendering of heat sink.

Colorized thermal map of heated plate.

Temperature distribution as a function of

x-location on the plate.

SEAN M. REIDY


SELF-BALANCING, TWO-WHEELED ROBOT

MEAM 510 – Design of Mechatronic Systems

November, 2013

Collaborators: Klyde Breitton, Nick Labarbera

OVERVIEW

The Acrobat was a self-balancing robot which used an inertial

accelerometer and gyroscope to stay on two wheels. This was

the penultimate project for our Design of Mechatronic

Systems class.


The robot kept balance by applying a motor torque from the

wheels to prevent the robot from tipping over.

Our acrobat robot featured a three tier structure, with motors

and circuitry on the bottom tier and a battery on the second

tier. The second tier had stabilizing wings that would help to

prevent the robot from falling completely over. The wings

also allowed the robot to sometimes bring itself back upright

after tipping too far over. Our robot had a wide base to allow

for stability and the ability to place most components as low

as possible to the wheel axis.

An accelerometer was mounted along the axis of the motors to

minimize noise caused by the radial acceleration of the robot.

Our code implemented a failure angle at which point the

motors would stop spinning. This allowed us to prevent the

robot from running off once it fell over. The failure angle

portion of the code can be seen in action at the ending of our

demonstration video where the robot lays still while resting on

one of the wings.

The code to determine the torque applied to the wheels

implemented Proportional-Integral-Derivative (PID) control.

The input for the controls was smoothed out using a digital

filter to eliminate noise.

OUTCOME

Our robot was able to start from an unbalanced position and

correct itself into an upright position. It was able to maintain

balance for well over 30 seconds. A video of the

demonstration can be found at the following link:

https://www.youtube.com/watch?v=7i9jIiKVaek

SolidWorks rendering of robot.

Finished Acrobat self-balancing.

https://www.youtube.com/watch?v=7i9jIiKVaek

SEAN M. REIDY


MODELING OF MECHANICAL DEVICE

MEAM 101 – Introduction to Mechanical Design

October-November, 2011

Collaborators: Daniel Blank, Daleroy Sibadna

OVERVIEW

Our team was tasked with creating a full 3D model of an

electromechanical device. In particular, we were to model an

electric jigsaw in SolidWorks. We took apart the jigsaw,

modeled each part individually, and joined all parts in a

SolidWorks assembly. We then made a video of an exploded

view of the jigsaw, showcasing the detail we put into the

model and renderings.


Our team split the components up and modeled them

individually. We first discussed which measurements for our

parts would be in common and ensured that those would be

the same, to avoid issues with joining the assembly later on.

For modeling the different components, most of the work

involved tedious measuring and recording. Many hours were

put into creating the most accurate model possible.

After individual modeling, our team joined our parts together

in a SolidWorks assembly. The parts were successfully joined

and the full assembly was complete.

The final task was to create an animated exploded view of the

jigsaw. This served to display all of the small, intricate parts

that were modeled in the jigsaw that would otherwise not be

shown.

OUTCOME

The final video can be viewed at the following link:

https://www.youtube.com/watch?v=dQE_O1u12Gk

Rendering of central shell of jigsaw.

Rendering of central motor of jigsaw.

Designing the central motor in

SolidWorks.

Final enclosed jigsaw model.

https://www.youtube.com/watch?v=dQE_O1u12Gk

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