# A Novel Drone Design Based on a Reconfigurable Unmanned Aerial Vehicle for Wildfire Management
## 3 Materials and Methods
### Estimation Design  
The first crucial step in the development process of a UAV is the estimation design. Focusing on key considerations such as electronic equipment, structural design, material selection, and assessing overall geometry and dimensions, this initial estimation stage lays the foundation for subsequent design decisions.  
1. Defining all the necessary electronic equipment to be installed on the drone is a crucial step in the design process. This includes the flight controller, power distribution system, global positioning system (GPS) antenna, wireless telemetry system, companion computer, and cameras. While some specifications may not be fully determined at this stage, estimates can be used to ensure that the design accommodates the intended electronic equipment.
2. The choice of materials for constructing the frame, arms, and landing gear is a critical aspect of the structural design of flying systems. The primary objective is to minimize the overall weight to reduce power demands for flight, extend flight duration, and enhance performance, all while ensuring sufficient structural stiffness to meet design requirements. One of the key factors contributing to this is the selection of suitable structural materials. In the case of this UAV, the main material chosen for construction was carbon fiber-epoxy composite. This material is characterized by its low density, approximately 1.6 kg of mass per litre volume, and it offers excellent mechanical properties, especially in stress, bending, and compression. It is available in various forms, including sheets of different thicknesses and tubes of varying diameters, making it versatile for various components of the UAV [35]. For structural components that may be too intricate to construct using carbon fiber elements, 3D printing with suitable materials, such as Nylon 12 powder, was employed. Additionally, stainless-steel bolted connections have been used where necessary for added strength and durability. In certain cases, commercially available aluminium components, like tube clamps and spacers, have been integrated into the design to meet specific requirements. This combination of materials ensures a well-balanced approach to achieving structural integrity and minimizing weight in the UAV's construction.
3. Based on the considerations outlined above, a preliminary layout was sketched to determine the overall geometry, dimensions, and the estimated total weight of the drone. This initial layout is an essential step in visualizing the UAV's physical configuration and understanding how its various components come together to achieve the desired design objectives.
4. With the parameters defined, including the overall geometry, dimensions, and estimated total weight of the drone, the number of rotors for the multicopter and the selection of motor and propeller sizes, electronic speed controllers (ESCs), and the size of the battery and power management system can be determined. These selections are crucial in ensuring that the drone's propulsion and power systems are well matched to its physical characteristics and mission requirements.
5. The equipment defined in step 4 can impact the earlier weight, size, and layout estimations made in step 3. Therefore, it is common to iterate between steps 3 and 4 until the final data output of step 4 converges with the results obtained in step 3.