PID = Proportional,Integral, Derivative.
I call them Power,Interference, Determination to more closely associate what they do in my brain. the dude in the video does a decent job teaching but is not exactly spot on in definition or use of it all. He also fails to mention that when changing pids you can drastically over heat and smoke motors if you just go swapping numbers randomly like he was doing. If he were using the cheapest parts possible like most builders these days that quad would have fried at least three times in that video.
P... "Power" of the rotation on the controlled axis. This determines how aggressive the inputs will be at the outputs. Basically how hard the changes attack in motion.
I... "Interference" of outside factors like wind, aerodynamics and torque effecting the stability of the craft. This is the push back against those forces and how strong the resistance will be.
D... "Determination" or how hard the controller works to smooth out the efforts of the other two controls.
P and D work as a team up to a point. I is the loner and works by itself as a guardian of P and D.
The first step in PID tuning is to find the rates you will be flying at first as those play a bigger part in how PIDS will function then most "tuners" explain. For example, if you just cruise around and say do cinematic video you want to tune for a non aggressive extremely smooth flight so you would not tune P too high and have the I term very tight to stiffen up any spastic movements in flight. For a flippy floppy freestyle flight you would want a higher P gain for the super crisp response to inputs and an I term setting just high enough to correct for snappy maneuvers and the torque needed to do them. Both styles use different rates and require different control expectations from the FC.
If I were to follow that video (and I just might for this new build I am just finishing) I would disable the filters as shown and begin tuning for different settings for the three styles of flight I want to do with it having it all on switches to change at will. This means I will need to set three rate profiles THEN begin the tuning process for each.
Once rates are set I will start with stock P gain and lower I gain by a third as well as D gains. (NEVER tune in auto leveling modes) I start by raising P gains in beta flight by 10 points with a quick flight to test response and motor temps. I will keep doing that until I get either a spastic response or start feeling higher motor temps on short flights. Then I will bump D gains up at intervals of 2 until the jitteryness eases up. I never use high d gains like most other pilots as I like to have super locked in feel no matter what I fly. I use it more at the end of P gain tuning to smooth out the roughness as well as for motor temp control.
Once that is feeling close to how I like it I will adjust I gains by doing punch outs straight up looking for any changes in yaw, pitch or roll as it goes thru the power cycle of hard throttle up to free falling back down. Once there is no dipping or twisting going up or coming back down I raise I gain a touch more to compensate for the higher average winds we have here.
Bottom line is tuning is a personal preference to how you fly so there is no magic number. You just need a good understanding of what the PID settings do and how to manipulate them to get the craft to do what you want and how you want it to feel. Just be very aware you can fry gear fast with drastic changes so small changes to find the edge of locked is better then big changes crossing that threshold and lighting your esc's and motors on fire.
