A method, system, and apparatus for a linear active disturbance rejection control with a fractional order integral (FOI-LADRC) action for set-point tracking of a process variable is disclosed. The FOI-LADRC method includes receiving and multiplying a reference signal by a first feedback signal, applying, by a set-point tracking controller, fractional order integration to the reference signal, amplifying and multiplying the reference signal by a series of second feedback signals and a third feedback signal, dividing the reference signal by a static gain, and generating a process control variable, inputting the process control variable and applying a disturbance to the plant to output an output signal, feeding back the output signal, as the first feedback signal, generating the series of second feedback signals and a third feedback signal by an extended state observer, ESO, and tuning the set-point tracking controller and the ESO to eliminate the disturbance, from the output signal.