Saturday, 24 May 2014

Importance Of Wheel In Robotics

After a long time I have come back to write about robotics. This time I am going to give you a little insight about mathematics and physics involved in robotics. This is going to be really interesting, so without wasting time "Let's dive in!".

Robotics is an interplay of mechanics, electronics and programming. As these are all related to science and mathematics, it is not unusual to find mathematics and physics in robotics. When you buy a motor for a robot one must always pay attention to information printed on it, mainly the rpm (rotations per minute) and the torque of the motor. These two quantities can be used to calculate the speed of the motor, force generated by it, its acceleration etc. 
To find the speed of the motor you just need the rpm of the motor and the radius of the wheel that you are using. Let's see how to do it.
Circumference of a circle = 2*pi*r where 'r' is the radius of the wheel.
Rpm tells us how many times a wheel rotates in a minute. If we multiply rpm with the circumference of the wheel, we will get the total distance traveled. Now 
Speed = distance traveled / time taken 
Therefore, speed = 2*pi*r*rpm since rpm gives us the number of rotations in 60 seconds. 
With this we can conclude that the speed of the motor is directly proportional to the radius of the wheel. So if you want a fast robot, use bigger wheels. But wait, what about force?

The force can be calculated by using the torque of the motor using this simple equation :-
Torque = Force * Perpendicular distance      
where perpendicular distance is the radius of the wheel. Since torque is a constant, which varies with motors, the force generated by the motor is inversely proportional to the radius of the wheel. 

In the end we can conclude that if you want a fast robot, use bigger wheels. If you want a robot that can produce a larger force for carrying things, then you need smaller wheels. That is why wheel is considered one of the most important and revolutionary inventions of all times!

If you want to get started in robotics, be sure to check these tips.