Request for Approval

Description

The request for approval (RFA) is the very first step in successfully completing a senior design project. Before submitting your RFA, you must post your project idea to the Web Board using the "Idea" post type. Once your idea has been fleshed out through the Web Board, you can move on request for approval through PACE under the My Project page. Once submitted, your project will be cloned to the Web Board as "Project Request" post. You can edit the project on the My Project page, add your teammates and see comments from the instructors. The course staff may provide feedback on your idea (which will appear at the bottom of your project's page), or suggest changes in the scope of the project and ask you to re-submit an RFA. Based on your incorporation of feedback your project will be approved or rejected. If it is rejected, the My Project page will revert back to it's original format and your project will disappear.

Once the course staff has approved the project idea, you will receive instructions on how to submit your project through PACE, at which time you will be assigned a project number in the Projects list, a TA, and a locker in the lab. Once your project is approved, please go to the Projects page, log into the PACE system, and make sure all of the information is correct.

Video Lecture

Video, Slides

Requirements and Grading

The RFA is graded credit/no credit based on whether your project is approved before the deadline. Note that submitting an RFA before the deadline does not guarantee approval before the deadline. The RFA is submitted through PACE under the My Project page, and should be Markdown-formatted with the following information:

# Title

Team Members:
- Student 1 (netid)
- Student 2 (netid)
- Student 3 (netid)

# Problem

Describe the problem you want to solve and motivate the need.

# Solution

Describe your design at a high-level, how it solves the problem, and introduce the subsystems of your project.

# Solution Components

## Subsystem 1

Explain what the subsystem does.  Explicitly list what sensors/components you will use in this subsystem.  Include part numbers.

## Subsystem 2

## ...

# Criterion For Success

Describe high-level goals that your project needs to achieve to be effective.  These goals need to be clearly testable and not subjective.

Projects must be legal and ethical. They must have significant scope and complexity commensurate with the size of the team. This is, of course, a subjective assessment of the course staff. To gain some insight into this judgment, please browse projects from previous semesters. The project must involve the design of a significant hardware component at the circuit level. In exceptional cases, projects not meeting this criteria may be acceptable when augmented by a Special Circuit assignment (however this is typically a last resort).

Beyond these basic requirements, you have total discretion in proposing a project. This is a great opportunity for you to pursue your own interests. Since you choose your own projects, we expect a high level of enthusiasm from you and your team.

Submission and Deadlines

The RFA submission deadline may be found on the Course Calendar. Typically, approval of the RFA is due during the afternoon of the third Thursday of the semester.

Quick Tips and Helpful Hints

Posting: Choosing a project: Choosing partners: Some general project ideas that are fraught with pitfalls:

Active Cell Balancing for Solar Vehicle Battery Pack

Tara D'Souza, John Han, Rohan Kamatar

Featured Project

# Problem

Illini Solar Car (ISC) utilizes lithium ion battery packs with 28 series modules of 15 parallel cells each. In order to ensure safe operation, each battery cell must remain in its safe voltage operating range (2.5 - 4.2 V). Currently, all modules charge and discharge simultaneously. If any single module reaches 4.2V while charging, or 2.5V while discharging, the car must stop charging or discharging, respectively. During normal use, it is natural for the modules to become unbalanced. As the pack grows more unbalanced, the capacity of the entire battery pack decreases as it can only charge and discharge to the range of the lowest capacity module. An actively balanced battery box would ensure that we utilize all possible charge during the race, up to 5% more charge based on previous calculations.

# Solution Overview

We will implement active balancing which will redistribute charge in order to fully utilize the capacity of every module. This system will be verified within a test battery box so that it can be incorporated into future solar vehicles.

Solution Components:

- Test Battery Box (Hardware): The test battery box provides an interface to test new battery management circuitry and active balancing.

- Battery Sensors (Hardware): The current battery sensors for ISC do not include hardware necessary for active balancing. The revised PCB will include the active balancing components proposed below while also including voltage and temperature sensing for each cell.

- Active Balancing Circuit (Hardware): The active balancing circuit includes a switching regulator IC, transformers, and the cell voltage monitors.

- BMS Test firmware (Software): The Battery Management System requires new firmware to control and test active balancing.

# Criterion for Success

- Charge can be redistributed from one module to another during discharge and charge, to be demonstrated by collected data of cell voltages over time.

- BMS can control balancing.

- The battery pack should always be kept within safe operating conditions.

- Test battery box provides a safe and usable platform for future tests.