Controller design for a fish robot to follow an oscillating source

PVDF sensors are used to measure the dynamic pressure surrounding a biomimetic autonomous underwater vehicle (BAUV). To track the motion of a periodically oscillating source by following the pressure generated by the source motion, the BAUV estimates pressure derived by its own, and subtract those information to find the signals of the source motion. Mechanics and motion control of the BAUV is derived. The BAUV's tail fin is then controlled to be an oscillator like mechanism. A dipole model is used to predict the dynamic pressure around the tail fin using the potential flow theory. A moving dipole source is then considered as an external source that is oscillating with constant amplitude and frequency. Relative phases between the tail fin and the dipole source are estimated using measurement from the PVDF sensor attached on the robot's body. Coupling forces based on the phase angle between the tail and the oscillating source are derived to drive the tail fin. Tank experiments employing a captured BAUV model beside a moving dipole mechanism are conducted to observe the phase following performance. The future application of this paper is directed to the control a group of fish robots.