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 | design_document1.pdf proposal1.pdf |
|
| **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. |
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