Do you have data that use only for one time and you think
you might not use it anymore?
You can reuse the data to create a model for your great benefit.
In this video, we are going to introduce
how to use LookUp Table with Simulink.
Specifically, we will talk about what LookUp Table is,
how to create a LookUp Table model, and the benefits
of using LookUp Table.
Although the basic LookUp Table concepts
are explored with a brake model, it
can be extended and applied to many other situations,
such as electrical, hydraulic, or thermal modeling.
Let's take an example of the brake model.
If we are driving a car, and if we want to stop the car,
we would step on the brake pedal.
In this case, we use sensors to get
the experimental data of brake pedal position and brake
torque.
The first question to answer is, what is LookUp Table?
LookUp Table is the name of block we use on Simulink.
We can create the model by putting data into LookUp Table.
Next question is, how to create a LookUp Table
model on Simulink.
We can open the Simulink browser by typing Simulink
in the Command Window or by clicking the icon on the Tool
Strip and click Blank Model.
And now we can create a model on this white canvas.
To get 1-D LookUp Table, click Library Browser, Lookup Tables,
and we can add 1-D Lookup Table by dragging
the icon from the library browser
and drop it to the canvas.
Now, we want to put data into Lookup Table.
By double-clicking Lookup Table, Block Parameters window
will pop up.
Table data and Breakpoints are the place
that we put our data in.
Let's say we have experimental data.
In this case, we have data for pedal position and brake
torque.
We want to know how much brake torque we can
get for a given pedal position.
Pedal position, or input data, we will put in Breakpoints 1.
And brake torque, or output data,
will be put in Table Data.
This time we put the numbers directly.
But if the variables are in the workspace,
we can also use variables.
If you want to know how to import the data to MATLAB,
we have a video for that.
So please find the link in the description.
Once we create the LookUp Table model,
now we can test the model by putting random value.
Click Run button and we get some number for the brake torque.
Let's see our original experimental data
to check if the result gets the same number.
We get 371.4 Newton-meter, 400% of pedal position.
It seems working.
Let's try another one.
This time we put 50 in the brake pedal position.
Click Run button and get some number.
This number is same as experimental data.
So our model is working.
Not only 1-D Lookup Table, but you can also
create 2-D Lookup Table by changing number
of table dimensions to two.
Again we have experimental data, but this time we
have two inputs, brake pedal position and temperature.
So we need to put two data into two breakpoints.
Now we created the model.
Not only 1-D and 2-D, but we can also create 3-D, 4-D, n-D.
It depends on the data you have.
Let's talk about the benefit.
When you create a model, you might sometimes face
the problem that you cannot create or find the equations
of the physical phenomenon, because of the uncertainties
of physics or complex calculations.
However, if you use your data to create a LookUp Table,
you do not need to use the equations.
Because you are not using complex equations,
you can save your runtime by using LookUp Table.
Those are the benefits of using LookUp Table.
Today, I talked about what LookUp Table is,
how to create a LookUp Table model, and the benefits
of using LookUp Table.
Now, it is time for you to create your own model
with LookUp Table.
Thank you for watching the video.
I hope you enjoyed it.