Clevis and Boathead was a term project for the course Design of Electromechanical Robotic Systems (2.017) during the Spring 2018 term. As a team of four students, we were responsible for the following aspects of the vehicle's design:
Constructing the mechanical structure of an unmanned boat
Designing controllers for autonomous navigation of specific, predetermined tasks
Implementing appropriate sensors and electronic components for safe operation and feedback control of vehicle
Performing real-time data processing for use in feedback control algorithms
My primary role in the project was sensor data acquisition and electronics integration. The feedback controllers required that the boat's position, speed, and heading be known with reasonable accuracy and be robust to disturbances such as wind, currents, and waves. To collect these measurements, I combined readings from a GPS module and IMU into a Kalman filter algorithm to provide estimates of the required states of the boat. I also collected these variables as data, performed post-task analysis, and confirmed quantitatively that the vehicle carried out the commanded task(s) as specified. Additionally, I was responsible for implementing a radio-controlled relay circuit which served a safety mechanism for the vehicle. See page 8 and pages 14-22 in the attached report for details on these specific contributions.
We were given three tasks for our boat to autonomously carry out in the Charles River near MIT's campus. These tasks, in increasing order of difficulty, were:
Travel in a straight line along a compass heading at constant speed
Travel in a closed circular path at constant speed with a radius centered around a GPS point
Autonomously approach a buoy, make a U-turn around the buoy and return to the starting location on the dock
Ultimately, tasks 1 and 2 were successfully tested and performed. Task 3 was tested but not successfully completed due to time constraints.
The below video shows both tasks 1 and 2 being performed by the boat in one run. The boat autonomously navigates in a straight line until it is approximately 30 meters away from the dock. It then begins its control algorithm to navigate in a circular path. The boat performs this circular path indefinitely until the boat's control is overridden to RC control and steered back to the dock.