Tuning Reduced-order Error-based ADRC for FOPDT processes using Magnitude optimum approach

Error-based Active Disturbance Rejection Control (ADRC) belongs to the family of ADRC controllers exhibiting superior disturbance rejection capability. This paper proposed a new tuning approach to select the parameters of reduced-order error-based ADRC. Instead of considering full-order error-based ADRC, a reduced-order version is considered in work to simplify its tuning and implementation. For the standard FOPDT model, a reduced-order error-based ADRC (ERADRC) is formulated, which is then transformed into its frequency domain. Then, using the FOPDT and ERADRC model dynamics, the coefficients of the magnitude optimum methods’ equations are identified. These equations are the functions of tuning parameters of ERADRC. The remaining parameters are obtained from the real positive solutions of the non-linear equations by fixing one of the parameters. The proposed tuning methodology is validated on standard benchmark test systems.