Project

# Title Team Members TA Documents Sponsor
25 Troll E: Tracked Robotic Outdoor Load-Lugging Escort
 Ben Wang
Daniel Ly
Hyun Been Park
 Tianda Huang
**Troll E: Tracked Robotic Outdoor Load-Lugging Escort**

Team Members:
Hyun Been Park (hbpark2)
Daniel Ly (dhly2)
Ben Wang (bw34)


**Problem**

Transporting groceries, tools, camping equipment, gardening supplies, and other heavy items can be difficult when a person is working or traveling alone. Traditional carts can assist people with carrying these weights, but still require the user to manually push or pull them.
These carts also become difficult to use when the terrain changes. Gravel, grass, and curbs can make conventional wheeled carts difficult or unsafe to operate.


Our goal is to design a robotic load carrier that can follow its user automatically and transport a rated load across different types of terrain without requiring the user to continuously control or pull the device.


**Solution**

We propose a multi-purpose robotic load carrier that follows a wireless beacon carried by the user.


The carrier will follow the user while maintaining a set distance and use onboard sensors to detect nearby walls, people, and other obstacles. If an obstacle is detected, the carrier will stop and adjust its movement to avoid a collision.


The main feature of the device will be its ability to travel over several types of terrain, including smooth indoor flooring, pavement, grass, gravel, and sand.


The device will also monitor the weight of the carried load. If the load exceeds the safe operating weight, the system will warn the user and will not be allowed to operate until the load is decreased and the safety risk is eliminated.


**Solution Components**

**User-Following Subsystems**

The user will carry a small wireless beacon that allows the carrier to determine the relative position of the user.
The carrier will use this information to:
Follow the user automatically
Maintain a predetermined following distance
Stop when the user stops
Stop if the beacon signal is lost


A beacon-based system is preferred over image recognition because it reduces the amount of image processing required and provides a dedicated signal identifying the correct user.
Possible technologies for the beacon include UWB, Bluetooth, or another suitable short-range wireless positioning method.


**Obstacle Detection Subsystem**

Distance sensors will be placed around the carrier to detect obstacles in its path.
The sensors will be used to detect:
People
Walls
Cliff/Slope
Large & Small Objects


Possible sensors could be distance sensors like LiDAR or Ultrasonic. We are leaning towards a combination of the two, as LiDAR may be good for seeing far, and the ultrasonics can help with managing the path due to smaller/closer obstacles. It may be beneficial to include bumper sensors as a failsafe option to prevent catastrophic failure and potential damage.


If an obstacle is detected within the required safety distance, the central controller will stop the carrier or determine whether a safe alternate movement is possible. For this to occur, we may need several identical sensors to check front and side views to find viable options of travel to navigate towards the beacon signal.


Additionally, we may need to include a sensor to detect when the cart is on a slope to ensure that no action is taken that may tip the carrier over or cause it to accelerate.


**Multi-Terrain Subsystem**

The drivetrain will provide the force required to move the carrier and its payload.
The system will be designed to operate on several representation surfaces:
Indoor flooring (smooth and carpet)
Pavement
Grass
Gravel
Sand
Wheel diameter, tire material, motor torque, and gear ratio will be selected based on the required load capacity and how well it will fare in all terrains.


The drive motors should be capable of steering and regulating their speed while following the user. This may include reversing in case the carrier is blocked off by obstacles.


**Load Sensing Subsystem**

Load cells or another suitable weight-sensing method will be used to measure the approximate payload placed on the carrier.


The system will compare the measured load against the maximum allowable operating load.
If the allowable load is exceeded:
The user will receive a warning
The carrier may prevent movement if the load creates an unsafe condition


**Control Subsystem**

A central microcontroller will receive information from:
The user beacon
Obstacle sensors
Load sensors
Orientation sensors
The controller will use this information to determine the required speed and direction of the drive motors.


The controller will also coordinate safety functions such as overload protection, obstacle detection, beacon response loss, and unsafe-angle detection.


**Power Subsystem**

A rechargeable battery will supply power to the entire carrier.
The power subsystem will provide the required voltage for:
Drive motors
Motor drivers
Microcontroller
Wireless communication
Obstacle sensors
Load sensors
Orientation sensors
Battery voltage will be monitored so that the system can warn the user when the remaining charge becomes too low for safe operations.


**Criterion for success**
Our solution can be considered successful if the carrier can:
Reliably follow the user’s beacon while maintaining a distance of approximately 2-3 meters under normal walking conditions.
Detect an obstacle in its path and stop before contact.
Carry a payload of at least 20lb across indoor flooring and at least three uneven surfaces such as grass, gravel, or sand.
Detect when the carrier is loaded above its allowable weight and provide a clear warning to the user.
Stop automatically if the beacon signal is lost.


**Extensions**

If the base project is completed successfully, possible extensions include:
A mobile application that allows the user to adjust following distance or operating mode
Manual remote-control mode
Automatic transition between flat ground
Battery state/battery charge display
GPS or location tracking
Detachable or expandable cargo compartments
Additional terrain options
Improved autonomous obstacle avoidance rather than simply stopping
Possible solar implementation for power conservation


**Safety and Ethics**

Because the carrier is an automatically moving device capable of transporting a significant load, user and bystander safety will be an important part of the design.


The carrier will include obstacle detection to reduce the risk of collisions with people or objects. An emergency-stop function will also be implemented, which will allow the user to disable the motors immediately if necessary.


The system will also stop if the user's beacon is lost or if the carrier is at an unsafe position.
The maximum load capacity will also be clearly defined so that the user does not operate the carrier beyond the tested safe limit.

Illini Voyager

Cameron Jones, Christopher Xu

Featured Project

# Illini Voyager

Team Members:

- Christopher Xu (cyx3)

- Cameron Jones (ccj4)

# Problem

Weather balloons are commonly used to collect meteorological data, such as temperature, pressure, humidity, and wind velocity at different layers of the atmosphere. These data are key components of today’s best predictive weather models, and we rely on the constant launch of radiosondes to meet this need. Most weather balloons cannot control their altitude and direction of travel, but if they could, we would be able to collect data from specific regions of the atmosphere, avoid commercial airspaces, increase range and duration of flights by optimizing position relative to weather forecasts, and avoid pollution from constant launches. A long endurance balloon platform also uniquely enables the performance of interesting payloads, such as the detection of high energy particles over the Antarctic, in situ measurements of high-altitude weather phenomena in remote locations, and radiation testing of electronic components. Since nearly all weather balloons flown today lack the control capability to make this possible, we are presented with an interesting engineering challenge with a significant payoff.

# Solution

We aim to solve this problem through the use of an automated venting and ballast system, which can modulate the balloon’s buoyancy to achieve a target altitude. Given accurate GPS positioning and modeling of the jetstream, we can fly at certain altitudes to navigate the winds of the upper atmosphere. The venting will be performed by an actuator fixed to the neck of the balloon, and the ballast drops will consist of small, biodegradable BBs, which pose no threat to anything below the balloon. Similar existing solutions, particularly the Stanford Valbal project, have had significant success with their long endurance launches. We are seeking to improve upon their endurance by increasing longevity from a power consumption and recharging standpoint, implementing a more capable altitude control algorithm which minimizes helium and ballast expenditures, and optimizing mechanisms to increase ballast capacity. With altitude control, the balloon has access to winds going in different directions at different layers in the atmosphere, making it possible to roughly adjust its horizontal trajectory and collect data from multiple regions in one flight.

# Solution Components

## Vent Valve and Cut-down (Mechanical)

A servo actuates a valve that allows helium to exit the balloon, decreasing the lift. The valve must allow enough flow when open to slow the initial ascent of the balloon at the cruising altitude, yet create a tight seal when closed. The same servo will also be able to detach or cut down the balloon in case we need to end the flight early. A parachute will deploy under free fall.

## Ballast Dropper (Mechanical)

A small DC motor spins a wheel to drop [biodegradable BBs](https://www.amazon.com/Force-Premium-Biodegradable-Airsoft-Ammo-20/dp/B08SHJ7LWC/). As the total weight of the system decreases, the balloon will gain altitude. This mechanism must drop BBs at a consistent weight and operate for long durations without jamming or have a method of detecting the jams and running an unjamming sequence.

## Power Subsystem (Electrical)

The entire system will be powered by a few lightweight rechargeable batteries (such as 18650). A battery protection system (such as BQ294x) will have an undervoltage and overvoltage cutoff to ensure safe voltages on the cells during charge and discharge.

## Control Subsystem (Electrical)

An STM32 microcontroller will serve as our flight computer and has the responsibility for commanding actuators, collecting data, and managing communications back to our ground console. We’ll likely use an internal watchdog timer to recover from system faults. On the same board, we’ll have GPS, pressure, temperature, and humidity sensors to determine how to actuate the vent valve or ballast.

## Communication Subsystem (Electrical)

The microcontroller will communicate via serial to the satellite modem (Iridium 9603N), sending small packets back to us on the ground with a minimum frequency of once per hour. There will also be a LED beacon visible up to 5 miles at night to meet regulations. We have read through the FAA part 101 regulations and believe our system meets all requirements to enable a safe, legal, and ethical balloon flight.

## Ground Subsystem (Software)

We will maintain a web server which will receive location reports and other data packets from our balloon while it is in flight. This piece of software will also allow us to schedule commands, respond to error conditions, and adjust the control algorithm while in flight.

# Criterion For Success

We aim to launch the balloon a week before the demo date. At the demo, we will present any data collected from the launch, as well as an identical version of the avionics board showing its functionality. A quantitative goal for the balloon is to survive 24 hours in the air, collect data for that whole period, and report it back via the satellite modem.

![Block diagram](https://i.imgur.com/0yazJTu.png)