Project

# Title Team Members TA Documents Sponsor
35 Bat Migration Monitor [PITCHED PROJECT]
Aidan Rafferty
Hoguer Benitez Hernandez
Romin Patel
Tianxiang Zheng design_document1.pdf
final_paper1.pdf
photo1.png
presentation1.pptx
proposal1.pdf
# Bat Migration Monitor [PITCHED PROJECT]

## Team Members:
- Aidan Rafferty (Aidanr4)
- Hoguer Benitez (Hoguerb2)
- Romin Patel (Rominmp2)

## Design Requirements:
- GPS tag that emits VHF
- VHF duration: 7-14 days
- Goal Weight: 1.5g
- Dimensions: 21 x 13 x 5 mm
- VHF range: 1 km
- Battery life: 3 days straight
- Data collection every 5-10 min periods over 6 hour timeframe
- Rechargeable
- Temperature Sensor

# Problem
The population of bats, whose presence provides pest control, pollination, and seed dispersal has been on decline due to various reasons such as WNS, habit destruction, and wind turbines(>400,00 hoary bats are killed by wind turbines annually). Due to the unawareness of their migratory path, minimum support has been provided in order to protect them. At the moment, there are VHF & Untraceable GPS tags currently available in the market, however, they both have their own downsides. The VHF tags are very labor intensive and only are beneficial when the bat is stationary. Untraceable GPS tags are unable to be retrieved which creates a lot of data loss of the paths. Additionally, both tags have a pricey dollar tag attached to both. In order to aid in bat conservation efforts, we need to learn more about the bats’ migration habits, which calls for the need of a new low-cost tracking product, such that it can improve the devices that are currently in the market in order to preserve the current population of bats.

# Solution
Our design is aimed to have low-cost VHF & GPS technology that can store the bat’s movement as well as send a signal for tracking data. This information will help us gather data for the bats’ winter-summer migration paths, and use it to prevent the further increase in bats’ casualties. For our design, it is essential to construct a device that incorporates a GPS tag integrated with VHF tracking capabilities to resolve issues that current devices have in the market. The construction of the device must ensure a weight below 1.5g and have an approximately 21x13x5 mm dimensions, such that the device would have no interference with the flight capabilities of bats.

# Solution Components
## Subsystem 1: Rechargeable Battery (Power)
The Power subsystem of the device requires us to use rechargeable batteries. We’ve looked at Lithium-ion and primary lithium cells, and we’ve decided to use Lithium-ion to meet the power density and rechargeable requirements. Due to the complexity of this project, we haven’t picked a specific battery, but due to the weight requirements, we want to stay in the range of 35-50 mAh. We have, however, picked a potential battery, but trade-offs and flexibility is still our priority here.

- Potential Battery - https://www.powerstream.com/ultra-light.htm
GM051215; 3.7 V; 50mAH; 1.2g

## Subsystem 2: Low dropout regulator
The LOD regulator will be used to bring down the voltage from the battery to the GPS and VHF. We’re going to stay away from designing our own voltage/current dividers and use the IC already in the market. Specific LOD regulator is still to be determined, however, since the battery we’re looking at will use 3.7V and the components use 3.3V, these are the specs we’ll look for.

## Subsystem 3: GPS Data Logging
For our project it is essential to have a device that is able to provide accurate position data of the bat. Beyond functionality, we also need to consider the dimensions and weight of the device as well such that it can comfortably be attached to the bat without hindering its flight capabilities. We believe that this chip would be suitable for our project as it fits within the dimension and weight constraints, while also still delivering the necessary functionality for tracking at very low power consumption. The data then would be written from the GPS module to the EEPROM chip by the microcontroller.
GPS Data Tracker - Max-M10M https://content.u-blox.com/sites/default/files/documents/MAX-M10M_DataSheet_UBX-22028884.pdf

## Subsystem 4: VHF Transmitter
The VHF transmitter system will be in the 148-152MHz band and needs to have a range of at least 1 km. The receiver used by the lab has a minimal detectable limit of -150dBm and -133dBm with the DSP using a 3 pole Yagi antenna with a gain of 7.7 dBi. Given the Wavelength of 2 meters and the incredibly small form factor requirements and omnidirectional need the antenna will be electrically small giving a predicted gain around 1.76 dBi. This means the transmitter will need to output at atleast 13 dBm to be detected by the receiver. The modulation scheme is a simple pulse of width 12ms and fundamental frequency of 1-.1 Hz. Right now we are most likely going to Use the ADF7020-1 Transceiver to accomplish the transmitter but are also continuing to work on a discrete component design and comparing designs for the Design Document. While the ADF7020-1 fits all the requirements perfectly, and has very low power draw in the off state, it takes up a rather large footprint and comes with a large amount of unnecessary features.

# Criterion For Success
In order to successfully complete this challenge, we need to be able to implement the data collection, VHF, GPS, and weight goal. The last three subsystems are vital to obtain the research data collection, and the weight is important due to the subject that we’re putting the device on, the bats. The rest of the specs would be greatly beneficial, but are not vital for the device to perform, hence we’ll categorize these as potential device enhancements.

Remotely Controlled Self-balancing Mini Bike

Will Chen, Eric Tang, Jiaming Xu

Featured Project

# Remotely Controlled Self-balancing Mini Bike

Team Members:

- Will Chen hongyuc5

- Jiaming Xu jx30

- Eric Tang leweit2

# Problem

Bike Share and scooter share have become more popular all over the world these years. This mode of travel is gradually gaining recognition and support. Champaign also has a company that provides this service called Veo. Short-distance traveling with shared bikes between school buildings and bus stops is convenient. However, since they will be randomly parked around the entire city when we need to use them, we often need to look for where the bike is parked and walk to the bike's location. Some of the potential solutions are not ideal, for example: collecting and redistributing all of the bikes once in a while is going to be costly and inefficient; using enough bikes to saturate the region is also very cost inefficient.

# Solution

We think the best way to solve the above problem is to create a self-balancing and moving bike, which users can call bikes to self-drive to their location. To make this solution possible we first need to design a bike that can self-balance. After that, we will add a remote control feature to control the bike movement. Considering the possibilities for demonstration are complicated for a real bike, we will design a scaled-down mini bicycle to apply our self-balancing and remote control functions.

# Solution Components

## Subsystem 1: Self-balancing part

The self-balancing subsystem is the most important component of this project: it will use one reaction wheel with a Brushless DC motor to balance the bike based on reading from the accelerometer.

MPU-6050 Accelerometer gyroscope sensor: it will measure the velocity, acceleration, orientation, and displacement of the object it attaches to, and, with this information, we could implement the corresponding control algorithm on the reaction wheel to balance the bike.

Brushless DC motor: it will be used to rotate the reaction wheel. BLDC motors tend to have better efficiency and speed control than other motors.

Reaction wheel: we will design the reaction wheel by ourselves in Solidworks, and ask the ECE machine shop to help us machine the metal part.

Battery: it will be used to power the BLDC motor for the reaction wheel, the stepper motor for steering, and another BLDC motor for movement. We are considering using an 11.1 Volt LiPo battery.

Processor: we will use STM32F103C8T6 as the brain for this project to complete the application of control algorithms and the coordination between various subsystems.

## Subsystem 2: Bike movement, steering, and remote control

This subsystem will accomplish bike movement and steering with remote control.

Servo motor for movement: it will be used to rotate one of the wheels to achieve bike movement. Servo motors tend to have better efficiency and speed control than other motors.

Stepper motor for steering: in general, stepper motors have better precision and provide higher torque at low speeds than other motors, which makes them perfect for steering the handlebar.

ESP32 2.4GHz Dual-Core WiFi Bluetooth Processor: it has both WiFi and Bluetooth connectivity so it could be used for receiving messages from remote controllers such as Xbox controllers or mobile phones.

## Subsystem 3: Bike structure design

We plan to design the bike frame structure with Solidworks and have it printed out with a 3D printer. At least one of our team members has previous experience in Solidworks and 3D printing, and we have access to a 3D printer.

3D Printed parts: we plan to use PETG material to print all the bike structure parts. PETG is known to be stronger, more durable, and more heat resistant than PLA.

PCB: The PCB will contain several parts mentioned above such as ESP32, MPU6050, STM32, motor driver chips, and other electronic components

## Bonus Subsystem4: Collision check and obstacle avoidance

To detect the obstacles, we are considering using ultrasonic sensors HC-SR04

or cameras such as the OV7725 Camera function with stm32 with an obstacle detection algorithm. Based on the messages received from these sensors, the bicycle could turn left or right to avoid.

# Criterion For Success

The bike could be self-balanced.

The bike could recover from small external disturbances and maintain self-balancing.

The bike movement and steering could be remotely controlled by the user.

Project Videos