Design and System Identification of a Miniature Underwater Vehicle for Controls Research

This thesis describes the development of an indoor water tank facility for controlsresearch and the design, testing, and system identification of a miniature underwater vehicle capable of three-dimensional motion. A visual tracking system was developed for the water tank that uses an overhead camera in conjunction with fiducial markers (AprilTags) to measure the vehicle’s planar position. A miniature unmanned underwater vehicle, or MiniUUV, was designed to serve as a prototype for future design iterations, which may involve bio-inspired locomotion and sensing, model-based path planning and control, or, by fabrication of additional vehicles, collective behaviors, and multi-vehicle coordination. The MiniUUV uses a differential propulsion drive and a peristaltic pump with a syringe for buoyancy control. Several experiments were conducted to collect data for identifying the MiniUUV’s dynamics. The experiments consisted of the vehicle performing various maneuvers such as moving in a straight line, circle, and zig-zag, and moving to various desired depths. Each maneuver was repeated several times with different control input profiles. These models can be used to simulate the MiniUUV and for control design in future work. System identification was conducted using a model-based method with linear regression and a model-free method with stepwise regression to identify and compare models of the MiniUUV’s dynamics.