Design of Autonomous Underwater Vehicle and Optimization of Hydrodynamic Properties and Control

Autonomous vehicles are becoming more and more prevalent in military, private industry and residential applications. Unfortunately, research currently being done in the area of autonomous underwater craft is often hindered by expense. It was desired to build a craft at WPI which could serve as an inexpensive test-bed for future research and implementation of control algorithms, etc. The vehicle\u27s construction required the design and manufacture of a number of components including water-jet stabilization thrusters, propeller driven main thrusters, a complete multi-hub electronic sensor and drive control system and individual sensors such as a tri-axial sonar unit as well as a capacitance based water-leak sensor. A Lexan heat forming process was also developed for hull construction

Direct AC/DC Rectifier With Mitigated Low-Frequency Ripple Through Inductor-Current Waveform Control

In a rectification system with unity power factor, the input power consists of a dc and a double-line frequency power component. Traditionally, an electrolytic capacitor (E-Cap) is used to buffer the double-line frequency power such that the dc output presents a small voltage ripple. The use of E-Cap significantly limits the lifetime of the rectifier system. In this paper, a differential ac/dc rectifier based on the use of an inductor-current waveform control methodology is proposed such that a single-stage direct ac/dc rectification without the need of an E-Cap for buffering the double-line frequency power, and a front-stage diode rectifier circuit can be achieved. The feasibility of the proposal has been practically confirmed in an experimental prototype.published_or_final_versio