KA MAP 1

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ABSTRACT ON KA MAP 1

QUADCOPTER

A project report on Quadcopter

 Submitted By Students of D.E.I.

• Amod Prasad
• Mohit Jouhari
• Karan Gandhi
• Pritam Kr. Singh
• Aman Sheel

QUADCOPTER

General Introduction-

This is basically a multi helicopter having four stretched arms. It could have many shapes but most successful one are “+”, “I”, “X” shaped.

It is propelled up by a four motors placed on its four arms respectively. A rotor is a combination of both propeller and motor .Rotors are use to generate both aerodynamics lift force that overcomes the weight of helicopter and intensity synchnorisation which commence aerodynamic drag in a forward motion.

They are simple aircrafts that use electronic stabilization to account for fact they remain precisely under our control during flight.

MAKING OF A QUADCOPTER

We will need-

1. Four Brushless motors, three phase speed control (for each motor), inertial measurement unit.
2. Aluminium  tubing <4x(300mm)>
3. Aluminium frame
4. A remote (wireless) – with V.R.s, push key switches, four pins single joys (two).
5. Landing gear
6. LEDs (combination of green and red) – to check connections.
7. Battery ( 4000 to 5000 mAh)
8. Four propellers ( 2 CW & 2 CCW)
9. Super glue

Before making our quad copter we must check out for it stability in air so we must consider the following:

1) Weight

Weight of quadcopter is one of the main issues so to avoid it we should use a light weight frame made up of wood, plastic or aluminum etc.

2) Design

We must also consider design with weight. The design must be such that it supports the flight of quad in air. It must have aerodynamic properties and since air resistance is not negligible so design must try to reduce air resistance.

STRUCTURAL ANALYSIS OF QUADCOPTER

As I said QuadCopters do have 4 motors with a propeller each. Most of the times the so called Brushless Motors are used to drive the propellers.

Brushless motors are a bit similar to normal DC motors in the way that coils and magnets are used to drive the shaft. Though the brushless motors do not have a brush on the shaft which takes care of switching the power direction in the coils, and this is why they are called brushless.

The reason why QuadCopters use brushless motors instead of normal DC motors is the much higher speeds and less power usage for the same speed. The brushless motors are more efficient as there is no power lost as there is in the brush-transition on the DC motors.

When looking for the brushless motors you should notice the specifications, especially the so called Kv-rating. The Kv-rating is an indication on how many RPMs the motor will do if provided with x-number of volts. The RPMs can be calculated in this way: RPM=Kv*U

On each of the brushless motors there are mounted a propeller. 

The four propellers are actually not identical. If you have a look at the picture above you will notice that the front and the back propellers are tilted to the right, while the left and right propellers are tilted to the left.

This reason for this is that the motor torque of and the law of physics will make the QuadCopter spin around itself if all the propellers were rotating the same way, without any chance of stabilizing it. By making the propeller pairs spin in each direction, but also having opposite tilting, all of them will provide lifting thrust without spinning in the same direction. This makes it possible for the QuadCopter to stabilize the yaw rotation, which is the rotation around itself.

In general you should select your propeller according to the following four tips:

1. The diameter of the propeller indicates how much air the propeller will be able to move while the pitch indicates how much air the propeller moves all the time.
2. The larger diameter and pitch the more thrust the propeller can provide. But be-aware that a large pitch makes it much harder for the motor to drive it, it requires much more power, but in the end it will be able to lift more weight.
3. When using low RPM motors you should go for the larger propellers as you can run into troubles with the small ones not being able to lift the quad at low speed (RPM)
4. A faster rotating propeller (small diameter and small pitch) is used when you have a motor that runs at a high RPM (Kv > 1000) and can provide a decent amount of torque.
5. A slower rotating propeller (longer or larger pitch) is used when you have a motor that manages fewer revolutions but can provide more torque.

For this matter lets just sum up what Roll, Pitch and Yaw is, as we are going to use these terms much more.

Roll, Pitch and Yaw is some well used terms from the aircraft terminology. The terms are used to describe the objects orientation around each of its axis. Have a look at the picture below and I think you will understand the terms.