To begin I want to thank you all. This kind of project change the way people make and think things. And I hope I will be able to give you back what you give to me…
I’m pretty new to brushless motor control. I just start making my own control few weeks ago to learn about brushless. For now I’m training on small gimbals and really small and sheep brushless driver with an arduino.
I tried to create my own control without watching other algorithme to keep my fresh eyes on this subject and possibly understand deep things about brushless.
Don’t be surprise to find strange language or idea here, I create my own technical language and theory around this subject.
Actually I have position, speed, and torque control working only with a position sensor on my gimbal motor so I choose to let me look at other algorithme to discover differences with my approche.
So I start (just start) looking at the Odrive code, and I found a lot of differences.
Current centric control
One of the main difference I found is the current centric control of the standard approach (the Odrive one). In my setup I don’t have current measurement and I don’t feel the need of measuring current for control purpose.
To evaluate the torque I compare the theoretical position of the rotor on" stepper mode" (I call it magnetic vector), and the real one given by my position sensor.
Is this “magnetic vector” thing is existing in standard brushless control approach?
So based on my observations a “magnetic vector” shifted with a given angle (9° in my motor) at the same volatage or PWM value give me more torque.
Here is my results :
The blue and red curve give torque at a fixed tension depending on angle difference between my “magnetic vector” and the rotor vector.
The yellow one is just a dynamixel XL320 measure for reference.
Is this delta angle performance thing something you heard about?
I will have A LOT OF questions after that, I will ask them later to keep this subject understandable.
Please feel free to chalenge/ask me about my strange approach.