I'm not doing any kind, kind of you know, feedback on, on how I should be moving.

So this, I think this a very key concept in

controls that And kind of motivates why it is that

we need state information or we need Feedback or even all

the stuff that you studied about you know, PID regulators, PI everything.

When you are minimizing the error you need Feedback,

you need output, you need to know where you

are in order to find even the error, how

far you are from, what you need to be doing.

For all this Feedback is a very important thing that you need.

So hopefully with all this, I have kind

of explained to you guys, the motivation behind why

you need to know where you are in the world.

And as you saw in the lectures Dr. Edgarson

goes over this whole thing of wheel encoders, right.

because if you have wheel encoders you will be to measure where you are.

Okay, for that again real quick. this is how the wheel encoder works.

Each encoder has N ticks, and a total of N ticks that

means if you over haul N ticks you would have moved one revolution

on the wheel which is two pi r on, you

know, your distance, and then you have Dl, Dr, Dc.

What is Dl, Dr, Dc is basically how much Your wheel is moving how

much distance the distance of this arc, for example, based on the number of ticks.

So that I have got 5 ticks how much I move?

what is this distance?

that is given by Dl, Dr, Dc. Dc is this.

You see all this before and then okay

once we had this of this is what you know, the wheel encoders

give us now what, how do we find where we are in space?

Okay, I know where I am in the beginning let's say I this is where I wake up.

Now I use DL, DR, DC in this form, in this update equation

and now I get my new position X prime, Y prime, and V prime.

And remember, X, Y, and V is my state, or where I am in place,

like X, Y, and looking there. That kind of a thing.

Okay, cool. So this whole thing is the wheel encoders.

This is how they work.

So just for your general you know, knowledge or curiosity

if you are wondering where did this model come from,

well we could go back to our, you know concepts

in physics really quick and we could be like, all right.

If this is a circle, if this is me walking on the circle with radius Small r here.