Development of a real-time navigation and collisionavoidance system for an autonomous naval rover : A Contribution to the Environmental Initiative for Flexible andReal-time Water Monitoring of the CatFish team

Abstract: This thesis explores the design and optimisation of a sensor system for real-time position determination of the Fish component in the CatFish naval drone and the development of a sonar sensor system for accurate object localisation and safe navigation in dynamic and uncertain underwater conditions. Through comprehensive experimentation and analysis, this thesis demonstrates the effectiveness of the proposed sensor system and sonar sensing system in enhancing underwater navigation and obstacle avoidance capabilities.  Additionally, research will compare two sonar systems: one using more expensive MaxBotix sonar sensors that are plug-and-play and don't need a lot of extra interfacing and data analysis. The other system utilises the cheaper CUSA ultrasonic transducers which needs a surrounding circuit and extra data analysis to work. The findings help researchers select the right system and improve sonar technology by identifying limitations and proposing enhancements to the systems. The research offers insights into building a self-built beamforming sonar array and addresses the deficiencies of commonly used ultrasonic systems. It provides valuable guidance for engineers and contributes to the advancement of ultrasonic technologies. The study also offers a unique comparison between user-friendly systems and simple transducers, aiding engineers in choosing the appropriate system for their needs. Overall, it enriches the field's knowledge and guides future developments in sonar systems. This thesis contributes to the advancement of underwater navigation in autonomous naval vehicles, providing valuable insights and recommendations for the design and optimisation of sensor systems and sonar sensing systems. The findings have implications for improving the navigational capabilities of the CatFish drone and contribute to the scientific understanding of sonar system performance under diverse conditions.