Introduction - If you have any usage issues, please Google them yourself
t control
An integral term increases action in relation not only to the error but also the time for which it has persisted. So, if applied force is not enough to bring the error to zero, this force will be increased as time pass. A pure "I" controller could bring the error to zero, however, it would be both slow reacting at the start (because action would be small at the beginning, needing time