introduction• An unmanned aerial vehicle (UAV), commonly known as a drone, is an aircraft without a human pilot on board. Its flight is either controlled autonomously by computers in the vehicle, or under the remote control of a pilot on the ground or in another vehicle.
Types of UAVs•Fixed wing UAV.•Helicopter UAV.•Quadrotor UAV.
What is quadrotor• A quadrotor, also called a quadrotor helicopter or quadcopter, is a multicopter that is lifted and propelled by four rotors
Why a quad-rotor UAVsQuad-rotor UAVs have many benefits:• Reliable• Compact• Low maintenanceBut• Limited payload• Limited flight time• Fast unstable dynamics
Quadrotoradvantage overfixed wing vehicle• Less desgin andcomplexity.• Minimal space for take-off and landing.
Quadrotoradvantage overhelicopter• Quadrotors do not require mechanical linkages.• The use of four rotors allows each individual rotor to have a smaller diameter than the equivalent helicopter rotor
Control of a Quad-Rotor UAV•Four variable-speed motors control each rotor individually•Front and aft rotors rotate opposite direction of left and right•Four-axis Control: •Roll – vary relative speed of left and right rotors •Pitch – vary relative speed of fore and aft rotors •Collective – vary speed of all rotors simultaneously •Yaw – vary relative speed of clockwise and counter-clockwise rotors•Highly maneuverable, minimal cross-coupling, simple control mechanisms•Low rate damping, requires electronic stability augmentation