QuadcopterQuad copter, quad rotor is a four rotors machine that can fly. Its working principle is as shown:

Principle:

1: Two diagonally opposite rotors are rotating in same direction. The two consecutive rotors will have direction opposite to each other. Hence the torque is cancelled and the net thrust is upward.

2. The Idea for direction control is Simple. The direction you want to move the Quad copter, slowdown that side Motor and speed up the corresponding opposite motor.

3. The Direction control, and rotational is given in fig .

Motors Used: There are options for Motors as:

Brushless Motor:

The most preferred motor for a quad copter is brushless motor, for its high Rpm/Volt, High thrust. But this is of very high cost and need of the Electronic speed controller.

These are the following Brushless DC Motors:

Features Brushless DCServomotors

Flat BrushlessDC Motors

Brushless DC Micromotors

Brushless DC Motorswith IntegratedSpeed Controller

Motion Control Systems

Nominal Voltage

6 ... 48 V 0 ... 12 V 3 ... 6 V 9 ... 24 V 24 V

No Load Speed

up to 100,000 rpm

20,000 ... 60,000 rpm

15,000 ... 100,000 rpm

1,000 ... 16,000 rpm

1.,500 rpm

Rated Torque

0.37 ... 202 mNm

0.05 ... 5 mNm

0.012 ... 41 mNm

1.8 ... 58 mNm

160 mNm

Weight 2.5 ... 750 g 1 ... 3 g 0.09 ... 2 g 16 ... 305 g 440 g

Links to DataSheets

[Click Here] [Click Here] [Click Here] [Click Here] [Click Here]

Coreless Motor:

I am thinking to use Coreless Motor, It is having good rpm/v for no load, and for a small quadcopter these may be good choice. The example of the quadcopter made by Coreless Motor is Hubsan X4.

Figure 1 Hubsan X4 quadcopter, palm size

These are following coreless DC motors:

Features Coreless DC Motors

Flat Coreless DC Motors

High Power PMDC Motors

Commutation Precious Metal or Graphite

Precious Metal Graphite

Nominal Voltage

1,5 ... 48 Volt 2 ... 12 Volt 24 ... 180 Volt

Speed 5000 ... 13000 rpm 5500 ... 10000 rpm 3000 ... 6000 rpm

Continuous Torque

0.11 ... 110 mNm 0.05 ... 3.0 mNm

Links to Data Sheets

[Coreless DC Motors Data Sheets]

[Flat Coreless DC Motors Data Sheets]

[High Power PMDC Motors Data Sheets]

Choice of Controller:

The choice of controller depends upon two main things:

PWM Technique for Controlling:

As discussed in Principle of working, we need to slowdown or speedup the motor according to the need of direction in which it has to be moved.

Lager the On time, More fast the DC Motor will rotate.

The PWM can be implemented in 8051 type microcontroller,(Same as example of flashing LEDs)

Remote Control:As the flying object should be remote controlled, and RF module must be used. Here is on question mark that “How to interface a RF module with The 8051?”:

Can we use a single transmit and receive pin for the data sending and receiving with the RF module? And we have to use a single channel RF module and then How the signal for the four motors can be send for by a serial Data communication.

Figure 2, SImple block diagram for Motor control using RF module

Figure 3, Circuit diagram for a RF Tx and Rx

Figure 4, Transmission of data in 8051 for motor control

Figure 5, Example Program for receiving data with 8051