The way I think of this is I think of the PGain as a multiplier value. When I tune a loop, I take the percentage of the error between the PV and SP and multiply that value by the PGain and that is how much the output will move. Higher the PGain, the bigger movement the PID will make the output value change. If you have a PGain of 1 and a 10% error in PV from SP, then the output will move 10%, PGain of 2 with the same 10% error, then the output will move by 20%. The Igain just repeats the PGain over time so for for every PGain move, the error between the PV and SP gets smaller and smaller over time to help get the offset of PV back to SP quicker.
That only holds true in a positional PID equation. AB uses a velocity PID equation. The PGain is multiplied by the change in the error, not the difference between the PV and SP. I think I need to do another video specifically about the differences between the positional and velocity PID equations to help with this.
Tim, I was taught P=whole number i.e.1.0, I=10th i.e. 0.1, and D=100th i.e. 0.001. I will have to try this the next time I do a PID. I deal with mostly Temperature slower to react. not sure if that makes a difference. Your Videos are very helpful, glad you decided to keep the channel going.
The challenge to this rule is it is going to depend on the equation. Check out this one where we talk about velocity vs position equations. twcontrols.com/lessons/pid-velocity-vs-positional-equation-studio-5000-pide-instruction
Currently i am preparing temperature close loop pid here due to intergral action output are saturated because temperature is slow moving parameter so what i want to do? For temperature control ON/OFF controller is better than the PID controller?
Here are my PID videos twcontrols.com/pid-control-proportional-integral-derivative A PID that pulses an output is still a PID, you just adjust your frequency of a sample rate timer ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-oKwK3uo_eVg.html
Love the videos so far....but there are some general rules of thumb that can be used instead of just changing values at a guess....which we rarely can do in real situations.
Yes there are. Upcoming videos include PID AutoTuning and running them through some manual equations to get decent ideas of what to enter. For this video I really wanted people to understand the relationship between the proportional and integral.
