DESIGN AND CONSTRUCTION OF A QUAD ROTOR CAPABLE OF LIFTING FROM THE FLOOR
CHAPTER ONE 1.0 INTRODUCTION An unmanned aerial vehicle (UAV) is an aircraft that does not carry a human operator. It is normally a powered aircraft that relies on aerodynamic forces to provide motion. This motion is controlled either by onboard computer (autonomous) or by remote control. Accurate methods of detecting and reacting to the UAVs environment are being developed; making some modern UAVs are virtually crash-proof (Merz & Kendoul 2013). Quadrotors are symmetrical vehicles with four equally sized rotors at the end of four equal length rods. Early designs of quadrotors were completed in the 1920‟s by Etienne Omichen, Dr. George de Bothezat and Ivan Jerome. These designs, however, never truly grasped the attention of the public or the in case of Dr. Bothezat and Jerome the military. Therefore, neither Omichen’s or Bothezat and Jerome’s were mass-produced. This fact, however, does not discredit the advantages of quadrotors. Unlike their counterparts, quadrotors make use of multiple rotors allowing for a greater amount of thrust and consequently a greater amount of maneuverability. Also, the quadrotors symmetrical design allows for easier control of the overall stability of the aircraft. Each of the rotors on the quad-rotor helicopter produces both thrust and torque. Given that the front and rear motors both rotate counter-clockwise and the other two rotate clockwise, the net aerodynamic torque will be zero, as seen in Figure 1.0 Fig. 1.0: Torque Pattern and Related Motion The generalized coordinates for rotorcraft are: q=(x, y, z, θ, φ, ψ) (1.1) Where (x, y, z) denote the position of the center of mass of the rotorcraft relative to the frame, and (θ, φ, ψ) are the three Euler angles that represent the orientation of the craft in figure 1.2 As UAVs are becoming more advanced and more practical, with longer flight times and larger payloads, more tasks are being found that they can perform. From pleasure activities to advanced military versions, UAVs are finding a bigger role in the modern world (Merz & Kendoul 2013). There are two types of UAVs, rotary-wing, and fixed-wing. Fixed-wing UAVs are Unmanned airplanes that use forward propulsion over a fixed airfoil to gain lift. They need a relatively high forward velocity in order to produce this lift and so are not suitable for operation in confined or hazardous environments. Rotary-wing UAVS can further be divided into another 2 types, single rotor, and multi-rotor. Single rotor vehicles are helicopters. They generally use a single large diameter rotor to generate lift and require a tail rotor for stability and direction control. Multi-rotor vehicles use multiple rotors to control all forms of motion (Kendoul 2012). 1.1 Aim of the Project The project involves the design of a quadrotor capable of lifting from the ground. Along with optimizing frame design and weight reduction, the control for the quadrotor was designed. With With the control on board, we were able to configure the flight controller of the quadrotor and allow the quadrotor to hover at a given altitude. Fig. 1.1: Body and Inertial Frame Coordinate Axis 1.2 Objective of the Project The major objective of this project is to design, implement and test a stable flying UAV. The the plane is to choose an existing quadcopter kit, couple the kits, and configuring each of the kits on the choosing flight controller.
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