As a project in my graduate mobility class, I replicated the results of “Target Tracking Control Design for a Robotic Fish with Caudal Fin” (reference included at the bottom of this page). The purpose of this project was to explore the methods of controllers that are able to regulate nonholonomic, or nonintegrable, systems.
I found several mistakes in the published paper. These errors were mostly due to the omission of minus signs, but it did yield a controller which was unable to regulate the fish to a given location. After working through the math with the appropriate corrections, and making some modification to the design of the controller, I was able to control the fish. The fish’s velocity was limited so that it could not travel backwards, but it was still able to reach a target position behind its initial position. In the above image, the fish begins at the origin facing to the right. The blue curve represents the fish’s path as it approaches the red target on the left, placed 10 centimeters behind the fish.
In this project, I demonstrated the following abilities:
1) The ability to learn quickly, demonstrated by my use of control techniques I was unfamiliar with.
2) The ability to recognize when original plans must be altered, shown by my willingness to alter the controller after derivation.