Decoupling Control of Distillation Column Based on Active Disturbance Rejection Control

Distillation tower process is a typical multivariable system, which has the characteristics of time-varying, coupling and time-delay. For multivariable systems, decentralized Active Disturbance Rejection Control (ADRC) can regard the coupling between channels as disturbance. Estimating disturbances through Extended State Observer (ESO) of respective channels may not eliminate coupling in time for strongly coupled systems. Based on ADRC's excellent tracking and anti-interference ability, the model's known information is fully utilized, and the multivariable extended state observer is adopted. The inverse decoupling design and ADRC are integrated into a complete multivariable control scheme to achieve better decoupling control. The simulation results show that the multivariable inverse decoupling ADRC control scheme can effectively estimate and compensate the uncertainties such as coupling and interference existing in the system. Its tracking capability and anti-jamming capability are superior to the conventional decentralized ADRC control scheme.