Quad Rotor or Quad Copter, also called a Quad-rotor Helicopter is basically a multi-rotor helicopter that is controlled by four rotors. Quad-copters are correspondent with rotor-craft as their lift is generated by a set of rotors (vertically oriented propellers), unlike the fixed wing aircraft.
Quad rotors are different from conventional helicopters that vary the pitch of the rotor blades dynamically as they move around the rotor hub. The quad rotors were seen as the realizable solutions to the vertical flight. As seen in the tail rotors of the helicopters that generate no useful lift, is eliminated by the counter-rotation in the quad rotors. Furthermore the rotor blades are short and much easier to construct.
In 1920’s and 1930’s manual designs appeared which were first successful designs of heavier than-Air Vertical-Take-Off-and-Landing (VTOL) vehicles. However the initial prototypes were less reliable as they provided more pilot work load, poor stability augmentation and the limited control potency.
As the Electronics advanced further the in late 2000, the cheap flight controllers, accelerometers or Inertial Measurement Units(IMU), Global Positioning System(GPS), and Cameras were added to the quad rotors. This advancement resulted in the formation of first unmanned aerial vehicles. As these quad rotors are having small size and good mobility, they can be flown both indoors and outdoors.
How is it designed?
With the mechanical simplicity of the quad rotors, they are cheaper and more durable than the helicopters. They cause less damage as the blades are short and possess less Kinetic Energy( KE) . Moreover they can be provided with a shield guards enclosing them, further reducing the potential for damage. The small blades are more advantageous over long blades. As the long blades provide more momentum, there is a negative impact on the control mechanism. The conventional helicopters do not experience such problem as increasing the blade size does not significantly impact the pitch of rotating blades.
The cheap and simple design makes a quad rotor as frequently used as recreational model Quad rotor helicopter project for engineering.
Quad-rotors generally use two pairs of fixed pitched propellers, two in Clockwise(CW) direction and two in Counterclockwise(CCW) direction. Each rotor has an independent variation of the speed for control over the quad rotor. By changing the seed of each rotor giving it assurance to get the desired total thrust, the center of thrust and the desired torque or a turning force.
DIY Quad Rotor!
Quad copters are becoming more far-flung because they are implausibly stable, fast and fun to fly. The emergence of Newer technologies have allowed development of smaller and cheaper quads with vast potentiality.
A quad-copter can provide dateless fun of flying similar to an (Radio- controlled )RC helicopter toy with cameras, these are also popular for taking professional aerial photos or videos, surveillance and 3D terrain mapping. Likewise they help build FPV (First person view) systems so that you can enjoy the experience as if you are a pilot inside the Quad-Copter!
RC helicopter toy –
For satisfying your curiosity to know how to design a Quad-copter, you can follow some industry-standard reference designs on Quad-copters. These reference designs may include the hardware and software design files, schematics, user guides and more…
Quad-copter For Ground/Air/Water UAV’s
There is Quad rotor or drone design that is a very popular design for ground, air and water unmanned aerial vehicles (UAV) and motor control utility. It has a flight controller and four electronic speed controllers (ESCs), one for each motor. The flight controller is accoutred with a radio to receiver flight commands provided by the pilot and the inertial measurement unit (IMU). The IMU provides information (such as velocity and positioning) which is needed for autonomous stabilization of the vehicle, using the internal accelerometer, gyroscope, and sometimes the magnetometer and GPS receiver. This design is based on a single Kinetics KV4x or Kinetis KV5x Micro Controller Unit (MCU) which helps to drive four BLDC motors of ESCs.
The Flight Dynamics
Each rotor produces both a thrust and torque about its center of rotation, as well as a drag force opposite to the vehicle’s direction of flight. If all rotors are spinning at the same angular velocity, with rotors one and three rotating clockwise and rotors two and four counterclockwise, the net aerodynamic torque, and hence the angular acceleration about the yaw axis, is exactly zero, which means there is no need for a tail rotor as on conventional helicopters. Yaw induces from mismatching the balance in aerodynamic torques (i.e., by offsetting the cumulative thrust commands between the counter-rotating blade pairs).
In order to allow more power and stability at reduced weight, a quad-copter, like any other multi-rotor can employ a coaxial rotor configuration.
Vortex ring state
Induced Flow Velocity During Vortex Ring State
Vortex Ring State
All quad-copters are subject to typical rotor-craft aerodynamics, including vortex ring state.
Mechanical components –
Frame, propellers(fixed pitch or variable pitch), electric motors.
Now a days carbon fiber composites are coming into fashion because of their light weight and structural stiffness.The motors and propellers should be equidistant for best performance and simplest control algorithms.
Electrical components –
electronic speed control module, on-board computer or controller board, and battery. A hobby transmitter is also there to allow for human input.
The PX4 autopilot system, an open-source software or hardware combination in development since 2009. It is adopted by both hobbyists and drone manufacturing companies alike to provide their quadcopter projects flight-control susceptibility.
Electric quad-copters have fugitive endurance when compared to similarly sized electric helicopters due to the little “disc area” of the rotor blades. The longest flight time achieved by a battery-powered quad-copter was 2 hours, 31 minutes and 30 seconds as per records.
Arduino-based UAV Helps in 3D Mapping
3D Terrain Mapping
ArduCopter is an open-source UAV platform that works on Arduino. It is an innovative autopilot system for multicopters, helicopters, and other rotor vehicles for applications like 3D mapping. The design offers both enhanced remote control flight (via a number of intelligent flight modes) and execution of fully autonomous missions. You can use respective web applications for sharing flight data , videos or even allow web-based control. Other features include automatic takeoff and landing and fail safety which detects when vehicle loses transmitter contact. A mission planner software is there to set up the Copter without any programming.You can use it to point and click way points to automate the mission and provide a route for the Copter, and provide visual displays for vehicle state, settings and telemetry.
Blade pitch or just pitch refers to turning the angle of attack of the blades of a propeller or helicopter rotor into or out of the wind to control the creation or absorption of power.
In physics, the kinetic energy of an object is the energy that it feature due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity.
A clockwise (typically abbreviated as CW) motion is one that payoff in the same direction as a clock’s hands: from the top to the right, then down and then to the left, and back up to the top.
A motion that is opposite in direction of clock’s hands.
Torque, moment, or moment of force is rotational force. Think of it as a twist or just as a linear force of push or a pull.
Thrust is a reaction force described quantitatively by Newton’s third law ( Action and reaction forces). When a system expels or accelerates mass in one direction, the accelerated mass will cause a force of equal magnitude but opposite direction on that system.
In fluid dynamics, drag is a air resistance, a type of friction, or fluid resistance. Simply it is an another type of friction or fluid friction. It is a force acting diametric to the relative motion of any object moving with respect to a circumferential fluid.
- Humanitarian operations
- Research platform
- Military and law enforcement
For designing you can go through the Robotics Online Course, IoT with Zigbee S2C & Arduino, IoT with LoRa and Arduino Uno. For better programming of Quad rotor you can refer Programming For All – Become Super Expert in Coding.
If this article is helpful, please drop your comments in the below comments section. It helps us to stay motivated! 🙂