Project

# Title Team Members TA Documents Sponsor
23 VR Force Feedback Gloves Restricting Side to Side Finger Movement
Yoonseo Choi
Aaron Gros
Sunghoon Kim
Jason Paximadas design_document1.pdf
final_paper1.pdf
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presentation1.pptx
proposal1.pdf
video
**Team Members:**
- Aaron Gros (aygros2)
- Yoonseo Choi (yschoi4)

**Problem:**

Current commercial force feedback VR gloves are too expensive for regular consumers and are only targeted towards industry and research. Open source force feedback VR gloves are economically accessible to regular consumers as long as they’re willing to spend some time putting them together. However, they are bulky and don’t restrict the finger’s side to side movement. The latter would be desired for a greater sense of immersion when for example grabbing an object between the sides of your fingers.

**Solution:**

We propose a new design for force feedback VR gloves that are still economically accessible to the regular consumer and that restrict the finger’s side to side movement as well as back and forward movement. The result would be that if a user tried to grab an object in VR with the sides of their fingers, this movement would be reflected in VR, and the movement of the fingers would be restricted when they collide with the object in VR. The same would be the case for trying to grab an object with the fingers’ back and forwards movement.

**Alternatives/Competition:**

These are some commercial alternatives that are too expensive for regular consumers: Sence Gloves and HaptiX.

Lucid Gloves is the most successful open source alternative but it lacks side to side force feedback and is bulky.

**Solution Components:**

**Glove:**

This includes the physical glove and its mechanical components that will enable the electronics to do their job. We will design and 3D print this component. It will consist of a mount to place all the other components on, a spider leg like fixture attached near the knuckle on one end and on the finger on the other end, and guides along the finger to hold the string.

**Back and Forwards Actuator:**

We will have a string attached to an actuator on one end and a finger tip on the other. The actuator will either be a small motor or an electromagnetic brake. The actuator will resist the extension of the string, which will apply force feedback to the fingers.

**Side to Side Actuator:**

We will have a plastic mechanism attached to an actuator around the knuckle on one end and a finger tip on the other. The actuator will either be a small motor or an electromagnetic brake. This actuator will resist the movement of the plastic mechanism therefore providing force feedback to the fingers.

**Back and Forwards Sensing:**

The string mentioned above will also be attached to a potentiometer. This will measure the movement of the string and therefore calculate the position of the finger.

**Side to Side Sensing:**

The plastic mechanism mentioned above will also be attached to a potentiometer. The movement of the mechanism will be the same as the side to side movement of the finger.

**Power:**

Although the final product should be wireless, to be able to focus on the force feedback components and not make the gloves too bulky, we won’t be incorporating a battery into the design and will instead have a wired connection.

**Processing and IO:**

We will use the ESP32 to read all the sensors and actuate all the motors as well as send the necessary signals to the computer.

**Criterion for Success:**

The gloves are able to:

- accurately track the finger’s position
- restrict the finger’s side to side movement
- restrict the finger’s back and forwards movement
- recreate the finger’s motion in VR
- correctly restrict the finger’s movement when they are in contact with a VR object

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.