BLDC Motor Control Road Map

The goal of this blog is to provide a basic roadmap for those who want to learn about BLDC/PMSM motor control theory. The readers are assumed to have basic knowledge about electronics.

The materials mentioned here are arranged from basics to advanced techniques. After finishing the material the reader should have a solid understanding of motor control theory such as commutation algorithm, PWM technique, PID controller, sensorless technique, field oriented control and flux observer.

I don't own any of these material, what I do here is to arrange the stuff in a progressive order so that you can learn smoothly.

For all the materials a rough study plan will be given according to author's learning experience.

Let's get started.

Sensored Commutation:
Brushless DC Motors & Control - How it Works (Part 1 of 2)
Brushless DC Motors & Control - How it Works (Part 2 of 2)
Suggested Learning time: 30 min
The "hello world" of motor control is Hall-sensor based 6 step commutation, and these two videos gives you a taste of how it works.


Sensorless Commutation:
Introduction to InstaSPIN™-BLDC Motor Control Solution

Suggested Learning time: 45 min

If you want to get rid of those sensors and build a more robust system, this video shows you exactly that; it's time to see how sensorless system play a role in motor control applications. 

Motor Control Tips & Guidelines:
The Ten Commandments of Digital Control (part 1)
The Ten Commandments of Digital Control (part 2)
The Ten Commandments of Digital Control (part 3)
The Ten Commandments of Digital Control (part 4)
The Ten Commandments of Digital Control (part 5)
Suggestd Learning time: 2 hrs
These blogs give you a guideline about digital control designs. Before moving to advanced techniques, it's important to refresh the building blocks.


PWM & H-bridge Basics:
So, Which PWM Technique is Best? (Part 1)
So, Which PWM Technique is Best? (Part 2)
So, Which PWM Technique is Best? (Part 3)
So, Which PWM Technique is Best? (Part 4)
So, Which PWM Technique is Best? (Part 5)
So, Which PWM Technique is Best? (Part 6)
So, Which PWM Technique is Best? (Part 7)
Suggested Learning time: 4 hrs
These blogs discussed in detail about PWM techniques for motor control application. PWM and ADC (Analog to Digital Converter) are two essenstial components for motor control, so it's important do know about them before moving to advanced techniques.


FOC (Field Oriented Control) Basics:
Field Oriented Control of Permanent Magnet Motors
Suggested Learning time: 2 hrs
FOC is a widely used motor control technique in industry. This video is a clear and straightforward explanation of field oriented control technique. Do your homework and fully understand this video; then you are in a good position to start learning FOC.


James Mevey's Master Thesis (The big paper for motor control):
SENSORLESS FIELD ORIENTED CONTROL OF BRUSHLESS PERMANENT MAGNET SYNCHRONOUS MOTORS 
Suggested Learning time: 100 hrs
Suggested Learning plan: Read this paper in parallel with motor control side projects or other materials.
This is a comprehensive discussion of FOC motor control technique from start to end. It is not easy to read, and I haven't finished it yet. From what I see, this paper connects all the dots in PMSM/BLDC motor control techniques in a very thoughful manner. If you want to fully understand motor control from the fundamental concepts such as law of physics, read this paper.


Sensorless FOC (Shane Colton's Paper):
Flux Observer-Based Sensorless Field-Oriented Control ofSurface Permanent Magnet Synchronous Motors (Gen. 1)
Suggested Learning time: unknown
First of all, here is Shane Colton's website:
http://scolton.blogspot.com/p/motor-controllers.html
This guy is good at making motor controllers, and by good I really mean GOOD. Check his website for MORE interesting stuff.
This paper discusses flux observer for sensorless FOC control; it's an advanced topic that I haven't done reading yet. What I can say is that the real challenge of FOC technique is its sensorless position estimation, not the FOC itself. If you want to make your theory level match the industry level, the sensorless technique is what you cannot avoid.



Besides the motor control roadmap, I want to mention some other sites that can help you understand or gain interest in motor control:
Teaching Your PI Controller To Behave
TI Motor Blog
VESC - Open Source ESC
ESC32 | AutoQuad
BLHeli32

Other resource links: (will be updated):
http://ww1.microchip.com/downloads/en/AppNotes/01078B.pdf

Have fun with motor controllers!  : )