For high-order systems

strong nonlinearities

parameter uncertainties and external disturbances pose significant control challenges. Several improved active disturbance rejection controller (ADRC) methods are proposed

including input modified ADRC (MADRC)

time-delay ADRC (DADRC) and Smith-like ADRC (SLADRC). These improved ADRC methods are systematically compared with conventional proportional integral (PI) control and regular ADRC

focusing on key performance metrics such as tracking accuracy and disturbance rejection capability. The effectiveness of the proposed improved ADRC methods is validated via numerical simulations of a typical superheated steam temperature (SST) system. The integral absolute error (IAE) of ADRC

MADRC

DADRC and SLADRC shows a reduction of around 30

50

33 and 35

respectively

relative to that of PI. The outcomes of numerical simulations demonstrate that improved ADRC methods achieve satisfactory control performance

whereas MADRC stands out with the best overall performance. Thus

field application data show that compared with PI

MADRC exhibits significant reductions in key deviation metrics

with the maximum positive deviation decreasing by 33

the maximum negative deviation decreasing by 8

the average positive deviation decreasing by 25

the average negative deviation decreasing by 11 and the variance deviation decreasing by 18.