Overall Progress
- Tested LiDAR sensor
- Tested H-Bridges for motor control
Risks & Management
One of the risks for the project is the issue with the H-Bridges. Since they were received as faulty, we were unable to test the motors and make significant progress on the robot’s movement. Thus, we bought new H-Bridges to replace the faulty ones and are looking into getting those H-Bridges refunded. If these new H-Bridges don’t work as intended, we are considering buying a robot car kit online to remove the risk of compatibility issues between components, so that our Interim Demo can show the code’s progress.
Additionally, the Raspberry Pi 5 we borrowed from the ECE inventory had a broken SD card holder, which made it so that we were unable to test the receiver iPhone to Raspberry Pi connection. To manage this, we ordered a new Raspberry Pi 5 immediately and continued to work on the software part of the communication. If the new Raspberry Pi experiences delays or if additional hardware issues arise, we can temporarily use a laptop-based server for testing.
Design Changes & Justification
In addition to using D* Lite for pathfinding, we also decided to test out the virtual force algorithm for local navigation as a way to avoid obstacles. This algorithm uses an attractive vector pointing from the robot to the next position and a repulsive vector pointing from the obstacle to the robot. These two vectors are added up to create the direction of motion. We decided to use this because it provides a reactive, real-time, obstacle avoidance. D* Lite by itself only provides the long-term goal of getting the cart to the user, rather than the short-term motions.