Design of an Autonomous underwater drone for achieving efficiency in the operation of the sensor package during monitoring of water bodies

Abstract: Background: the process of water quality monitoring is a critical quality assurance process. However, conventional methods include monitoring by a team of divers going to different depths to collect water samples. This method is expensive, time-consuming, and can lead to adverse consequences like a fatality.  Objectives: This study aimed to develop a robust, autonomous prototype for water quality monitoring. The idea was to measure water quality at a depth of 20 meters by designing an unmanned underwater drone with sensors for measurement and tracking.  Methods: a detailed literature review was conducted and trend watching, tech watching, and benchmarking were some strategies used to extract design ideas. After creating a good scope, various design ideas were iterated to solve the problem. Two concept designs of the underwater drones were selected and evaluated by a discussion matrix. The design idea that best fit the project requirements was selected and produced. Stress analysis was performed on the final design to check design performance at a depth of 20 meters.  Results: Design Fish 2 was chosen as the final design of the prototype. The selected design is manufactured from S316 stainless steel which is the material used for the shell while the rest is PLA.  Conclusion: The prototype has a hollow, cylindrical body that provides low hydrodynamic resistance, and the vertical design provides better stability when moving underwater.