Autonomous Water Sampling Payload Design

Abstract

Ideally, water sampling process is conducted due to the need for physical, chemical and bacteriological analysis. Difficult access of water bodies, excessive need for personnel, time, and costs are factors that contribute to the complexity of the sampling process. In order to overcome these challenges, a water sampling payload unit is developed and mounted on Lockheed Martin’s multirotor Unmanned Aerial Vehicle (Indago UAV) for autonomous water sampling. In this work, the allowable requirements of the sampling unit in terms of weight, size, and dimensions have been given by the Lockheed Martin due to the limitations of Indago UAV. The developed unit is an integrated system that includes winch system, cup, sterilized sponge, spherical weight, and software. The winch system is used to lower and lift the cup and its components. The cup is well-sealed in order to prevent the sample from any dust, water or air when the winch is lifting the sample, however it is designed where allowing a water to flow in when the cup is reaching the water. It contains a sterilized sponge that absorbs the inflow water. A trapezoidal weight below the cup connected to the winch via a fisher line is used to lower the cup contents into the water and to seal the cup contents when the winch lifts the sample. The unit also includes height sensor and release mechanism. The height sensor detects the UAV’s height above the water. Once the required height is reached, the winch will start lowering the cup. When the required sample has been taken, the cup will move back up by the winch and will be sealed by the trapezoidal weight in order to avoid any spillage of water. The advantage of developed water sampling payload unit is to get the water sample without the need for an individual diver or boat and to provide a safer way to prevent contact with dangerous fluids. Moreover, it can be used to take a sample from a body of water that is difficult to access, possibly off a major road in sand or forest and spill dams of a mine site could be analyzed.