Pod V Reveal

Pod 5 Overview

Hello, and welcome to Badgerloop Pod V Reveal. Last fall we began with the intent of designing a pod that would handle the foreseeable rules of the next competition. Despite not hearing word from SpaceX regarding the competition, we pushed forward with this plan to prepare for what we believed would be the most likely scenario for the next competition. We continued on this path until February, when the executive team re-evaluated our high level direction. We realized that the path we were on had strayed from our organization's mission and goals, and that we needed to rectify this. Our mission statement is to “Provide an unparalleled learning opportunity that fosters innovation and hands-on experience”. Following our mission statement, we pushed forward, developed safety procedures, and built this pod.

The Pod

Battery

The high voltage battery pack for Pod V consists of 90 8 Ah LiFePO4 pouch cells connected in series to give a pack voltage of about 297 volts. We split the 90 cells into six modules of 15 cells each for easy maintenance on the battery pack. The voltages and temperatures of each cell are captured through voltage taps and thermistors which are processed by our Orion Battery Management System. The BMS sends that data through a Control Area Network to the pod’s external dashboard where it can be read by a user.

Low Voltage

The low voltage electrical hardware system provides an interface between our mechanical systems and the electronics controls that guide our run in the tube. To achieve this integration, we designed two printed circuit boards that contain hundreds of electrical components each--the Braking IO and Main IO boards. First of all, when our pod needs to brake, the Braking IO board translates a message from our sensors or software into an electrical signal that actuates the braking system. Secondly, the Main IO board is connected to the entire electrical system. It provides safe communication between our main software controller, the high voltage system, battery management system, and our entire sensor suite.

Analysis

The Analysis subteam is responsible for the team’s effort in ensuring the pod’s viability through collecting all the hand calculations and documentation on the pod substructures as well as creating detailed FEAs. For Pod 5, the Analysis team's focus has been on creating more detailed models of Pod 4 structures that would be used again on Pod 5 as well as helping to compile test data to prove these FEAs validity.

Propulsion

The Pod 5 propulsion system consists of two main components, a cooling loop and the drive system. The cooling loop is currently set up to cool the motor controller, but has the capability to cool the motor and the motor controller. The loop goes from a 1 L reservoir through a filter to the pump. The coolant is then pushed through the motor controller and back into the reservoir. If motor cooling was necessary the flow would be split right before entering the motor controller and converge at the reservoir. The drive system is composed of an in hub direct drive motor. The motor is a three phase electric motor and is powered by our high voltage system. It takes an input of AC current from the motor controller. The wheel is coated in polyurethane to increase friction on the I-beam. The wheel assembly (with the motor inside) is sandwiched between two aluminum plates and mounted to the chassis. It is able to pivot about the fulcrum with a suspension system in the rear to absorb track bumps.

Controls

Controls is the brain of the pod! The controls team is in charge of writing the code to make our pod do exactly what we want it to do. The controls team thinks through the expected life cycle of the pod like turning on, spinning the motor, braking, and turning off (with a few states in between) and implementing that in code. We interact with temperature and pressure sensors as well as our motor and battery management system. Through our code, we can ensure the pod is always functioning optimally and if needed take action to safely shut down.

High Voltage

he high voltage team completed testing and inspection of the motor controller in a vacuum environment that allowed for the elimination of the bulky and complex pressure vessel it was previously housed in. Additionally, a new circuit board was taken from concept to functional design, referred to as the “precharge board”. This circuit board facilitates the high voltage charging of the capacitors in the motor controller, electrical isolation of the high-voltage system, and physical clearances that minimizes the risk of electrical arcing.

Braking

The pod’s braking system consists of two independent sets of friction brakes. The pneumatically-actuated pads clamp onto the vertical web of the I-beam, rapidly decelerating the pod. The primary braking system is located behind the secondary system, so in the event of mechanical failure or malfunction the secondary system will still be able to brake properly. The two systems differ only in pneumatic logic, with the primary being “normally-closed,” and the secondary “normally-open.” The brake pads are mounted to pivoting arms, which make contact with the I-beam when pushed inward by the pneumatic actuators. The braking mechanism is mounted to the pod channel via a robust U frame, which absorbs the force exerted by the actuators.

Stability

The stability sub team is responsible for designing building and testing systems to keep the pod lined up and prevent it from being knocked around. We have a few different systems which prevent different unwanted motion. We have the lateral system so stay lined up on the I-beam from side to side. We have the vertical system to prevent being knocked around by bumps and gaps in the subtrack. We also have pitch and roll systems to prevent rotation in those directions.

Electrical Reliability

The electrical reliability team is a new electrical sub team for Badgerloop. It was created to have someone responsible for testing, quality assurance, and integration on the entire electrical system. With any prototype system, bugs and hardware errors are bound to happen and this year the team worked to quickly resolve those issues so development can continue to move forward. The electrical reliability team also worked toward some new testing hardware and debugging tools to aid with the rapid prototype process and data collection tools to better characterize our LV batteries.

Software

Every pod needs an operator and Software is the team to let that happen. The software team is in charge of creating the dashboard that allows our engineers to interact with the pod. This involved receiving and processing several hundred data points a second and commanding the pods internal state machine. As engineers we like to test again and again until it's perfect. Part of the dashboard's data processing capabilities is to record and save each run to be reviewed by our engineers later. As well as the dashboard the software team is in charge of various software tasks around the team including maintaining the teams Bill of Materials WebApp.

Mechanical Reliability

The mechanical reliability team has a wide variety of responsibilities on the team ranging from machining parts to electro-mechanical integration to testing. This year, the mechanical reliability team designed the enclosures that contain the electrical team's printed circuit boards. They can be seen mounted all around the pod's chassis. Additionally, many members of the mechanical reliability team spent time in the machine shop producing parts to aid the propulsion team, the stability team, and more. Another contribution the mechanical reliability team made to this year's pod was testing the retro-reflective sensors with the help of the low voltage team, a bicycle, and a little creativity. All in all, the mechanical reliability team has many responsibilities and the team's contributions can be seen throughout the pod.

Structural

The structural team's main goals are to design/update the chassis of the POD, manufacture the mold, chassis, and shell, and work with other mechanical and electrical sub-teams to locate and mount components to chassis. For this pod, the structural team worked to fabricate a new chassis with the newly machined aluminum mold. Due to unforeseen circumstances, the newly fabricated and cured chassis was unable to be utilized for this pod. The structural team was able to use the structure from pod iv to accommodate the new electrical and mechanical subsystems. With the help of multiple members, we were able to design and create new jigs for accurate hole drilling for the mounting of other subsystems. A brand new carbon fiber processing room also allowed us to fabricate a new honeycomb core backplate for the structure.

The Team

Executive

President
Nathan Berg
Electrical Director
Shelby Riggleman
Mechanical Director
Bryan Tanck
Operations Director
Vito Gerlach

Team Leads

Battery
Andrew Cook
Controls
Eric Udlis
Electrical Reliability
Kevin Guenthner
Low Voltage
Lucas Maddox
High Voltage
Wyatt Dvorak
Software
Daniel Kouchekinia
Analysis
Joshua Lueth
Braking
Katie Argo
Mechanical Reliability
Joe Seifert
Propulsion
Alex Wells
Stability
Sebastian Thompson
Structural
Hannah Schilling
Communications
Mika Chang
Feasibility
David Garrelick
Finance and Supply Chain
McKenna Ruppert
Industry Relations
Cade Geldreich
Outreach and Recruiting
Ryan McFarlane
Virtual Reality
Nick Stoffel
Website
Luke Houge

Engineering Expo Experiments