Project

# Title Team Members TA Documents Sponsor
2 LiftSense - Olympic Lifting Technique Analyzer
 Chase Johnston
Ethan Filzone
Rohin Kumar
 Jonathan Hoff design_document1.pdf
final_paper1.pdf
photo1.JPG
presentation1.pptx
proposal1.pdf
# Team Members (NetID):
Rohin Kumar (rohink2) | Chase Johnston (clj2) | Ethan Filzone (efilzo2@illinois.edu)

# Problem:
Olympic Lifting is a sport that comprises of two lifts. The Clean & Jerk and the Snatch. The Clean & Jerk is the movement of a barbell from the ground to the shoulders, then from the shoulders to overhead. The Snatch is the movement of a barbell from the ground to overhead in one movement. Both of these lifts require a very high level of technique and years of practice to master. The optimal technique for these lifts is to for the barbell to travel at a 180 degree angle from the ground to overhead without any deviation. In addition, it is imperative to accelerate the barbell as fast as possible between the 1st pull (From the ground to above the knee) to the 2nd pull (From the knee to either the shoulders or overhead). All this must be done while maintaining a high velocity on the barbell throughout both the 1st & 2nd pull of the lift.

# Solution Overview:
We plan on creating two lightweight attachments equipped with a high performance IMU to achieve the metrics that we plan on collecting. These metrics are the path of the barbell, velocity and acceleration. All of these metrics will be collected as a function of time (ie: 1 Clean & Jerk or 1 Snatch). These lightweight attachments are planned to be attached onto the weightlifting clips. The reason being the weight will be evenly distributed on both sides as well as these attachments will be a minimal hindrance to the lifter (ie: The attachment is not in the line of sight of the lifter - not in between the weights, but on the outside of the weights). All of the data gathered from the sensors will be processed and displayed on a simple phone application that will allow olympic lifters to receive instantaneous feedback of each lift in near real time.

# Uniqueness/Differentiators:
This idea has almost never been done before. The only similar competitor in this space is an Android application called “Barsense Weightlifting Log”. This application tracks the barbell path as well as velocity. However, the application uses computer vision algorithms rather than sensors to gather these metrics. Using computer vision algorithms for a task like this versus actual sensors will certainly lead to inaccuracies in the velocity and acceleration metrics for this application. In addition, the app currently seems to not be working for many users as indicated by its three star review.

# Solution Components:

## Sensor Subsystem:
Two IMU sensors to capture acceleration, velocity, and position information from each clip attachment.

## Processing Subsystem:
Internal micro-controller for A/D conversion and other light data processing. Will be used to manage communication if needed
Bluetooth to send data from micro-controller to external server.

## Power Subsystem:
Manages output from wall adapter to appropriate power levels to charge small lithium ion batteries (handles overcharge/battery protection).Indicators for charging/full charge.Converts battery power to required sensor, micro-controller, and communication module demands.

## Front-End Application:
Data is further processed from server and presented to the user quickly ( < 2 minutes) and in meaningful/useful way.

# Criterion For Success:

## Hardware:
The Olympic Lifting Technique Analyzer accurately tracks the barbell path throughout the course of one entire lift. The velocity and acceleration metrics are accurate in conjunction with the current position of the barbell.

## Software:
These metrics will be displayed on a simple Android application for Olympic Lifters to receive feedback on their lifts within a couple of minutes (< 2).

## Design:
The attachments will not interfere with the Olympic Lifter during the actual lift itself. This means the weight of the attachments must be roughly equal on both sides (< 1 Pound deviation in weight between the attachments). The attachments must be out of the line of sight of the lifter.

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.