Hello.
Starting today, I’d like to delve into a very interesting story.
On this blog, we are currently experimenting with various peripherals using Infineon and NXP MCUs.
MCU stands for Micro Control Unit, and within it, not only the CPU, RAM, and Flash but also various peripherals needed for control are packaged together.
In other words, an MCU can be understood as a specially designed computer for controlling something.
So, what does it mean to ‘control something’?
If you watch the video below, you’ll see that we are currently rotating the wheels using a DC motor.
However, I want to ‘control the speed’ of this.
In this context, the rotation speed of the wheel is commonly expressed in RPM, which stands for Revolutions Per Minute, indicating ‘the number of revolutions per minute.’
In other words, it signifies how many rotations were made in one minute.
And, I have designed the speed control as follows.
Currently, I am giving speed commands (70rpm -> 45rpm -> 80rpm -> 50rpm),
and you can see in the diagram below how the wheel rotation is controlled according to these speeds.
In other words, I am controlling the DC motor at the desired speed. This is called ‘speed control.’
This can be seen as an example of control.
To perform control, additional studies beyond MCU knowledge are required.
To achieve the control I am performing, I have used the following feedback control theory and designed the controller in software.
For feedback control, an encoder to measure the motor speed is also necessary.
I want to convey that the purpose of studying MCU is not just limited to operating peripherals.
To illustrate further, consider the process of adjusting the water temperature using a boiler. In this case, a control logic similar to the speed control mentioned earlier would be in operation. A sensor measures the water temperature, sends the data to the MCU through ADC, and based on that data, a motor (or some other actuator) is controlled to adjust the water temperature.
The same principle applies to autonomous vehicles. Ultrasonic sensors measure the distance to the vehicle in front, send this data to the computer, and control the motor to maintain a certain distance by adjusting the speed.
Now, let’s perform control once. This requires a bit of study on this topic. Even though I checked the textbook I used during my university days, my memory is a bit fuzzy. However, a clear understanding of this topic is necessary for designing control using MCU.
So, let’s start with the next post.
