CHAPTER I
INTRODUCTION
A quadcopter, also called a quadrotor helicopter or quadrotor, is a multicolor helicopter that is lifted and propelled by four rotors. Quadcopters are classified as rotorcraft, as against fixed-wing aircraft, because their lift is generated by a group of rotors (vertically oriented propellers).
Quadcopters generally use two pairs of identical fixed-pitched propellers; two clockwise (CW) and two counterclockwise (CCW). These use independent variations of the speed of every rotor to realize control. By changing the speed of every rotor it’s possible to specifically generate a desired total thrust; locate the middle of thrust both laterally and longitudinally, and to create a desired total torque, or turning force.
Quadcopters differ from conventional helicopters, which use rotors that are ready to vary the pitch of their blades dynamically as they move around the rotor hub. In the early days of flight, quadcopters (then referred to either as ‘quad rotors’ or simply as ‘helicopters’) were seen as possible solutions to some of the persistent problems in vertical flight. Torque-induced control issues (as well as efficiency issues originating from the anti-torque rotor, which generates no useful lift) are often eliminated by counter-rotation, and therefore the relatively short blades are much easier to construct. Several manned designs appeared within the 1920s and 1930s. These vehicles were among the primary successful heavier-than-air vertical takeoff and landing (VTOL) vehicles. However, early prototypes suffered from poor performance, and later prototypes required an excessive amount of pilot workload, thanks to poor stability augmentation and limited control authority.
In the late 2000s, advances in electronics allowed the assembly of cheap lightweight flight controllers, accelerometers (IMU), global positioning systems, and cameras. This resulted in the quadcopter configuration becoming popular for small unmanned aerial vehicles. With their small size and maneuverability, these quadcopters can be flown indoors as well as outdoors.
Fig.2 Working of Quadcopter Drone
At a little size, quadcopters are cheaper and more durable than conventional helicopters thanks to their mechanical simplicity. Their smaller blades also are advantageous because they possess less K.E., reducing their ability to cause damage. For small-scale quadcopters, this makes the vehicles safer for close interaction. It is also possible to suit quadcopters with guards that enclose the rotors, further reducing the potential for damage. However, as size increases, fixed propeller quadcopters develop disadvantages relative to conventional helicopters. Increasing blade size increases their momentum. This means that changes in blade speed take longer, which negatively impacts control. Helicopters don’t experience this problem as increasing the dimensions of the rotor disk doesn’t significantly impact the power to regulate blade pitch.
A quadcopter drone, also known as a quadrotor helicopter, is a type of unmanned aerial vehicle (UAV) that is lifted and propelled by four rotors. It is a multi-rotor aircraft that is capable of vertical take-off and landing (VTOL), making it highly versatile for a wide range of applications.
Quadcopter drones have gained popularity in recent years due to their ability to be used for aerial photography and videography, as well as for various other applications such as surveying, mapping, inspection, search and rescue, and delivery.
Fig. 3 Quadcopter Drone
One of the key features of a quadcopter drone is its stability. The four rotors provide a stable platform, making it easier to control the drone in the air. Additionally, quadcopter drones are equipped with a variety of sensors, including accelerometers, gyroscopes, and GPS, that provide information on the drone’s orientation, speed, and position, which helps to maintain stability.
Quadcopter drones are usually controlled by a remote controller or a smartphone app, which allows the user to adjust the drone’s speed, altitude, and direction. Some quadcopter drones also come with features such as obstacle avoidance, automatic landing and take-off, and pre-programmed flight paths.
Another advantage of quadcopter drones is that they are relatively easy to repair and maintain compared to other types of aircraft. In case of a crash or damage, individual parts can be easily replaced, making it possible to quickly get the drone back in the air.
Despite their many advantages, quadcopter drones are subject to regulations and restrictions in many countries due to safety and privacy concerns. For example, it is often illegal to fly a drone over populated areas or near airports, and there are strict rules on the use of drones for commercial purposes.
In conclusion, quadcopter drones are a highly versatile type of unmanned aerial vehicle that have a wide range of applications. They are easy to control and maintain, but also subject to regulations due to safety and privacy concerns. As technology continues to improve, the potential uses of quadcopter drones will likely continue to expand.
