Reduced order model based design of linear active disturbance rejection controller with applications

This paper presents an improved linear active disturbance rejection control (LADRC) technique. The concept of model order reduction is incorporated in the design of LADRC controllers for the simplification of complex higher order systems, leading to the ease of tuning, simplification of analysis and reduction in the number of controller and observer parameters. The corresponding generalized formulae are derived. The efficacy of the improved LADRC scheme is then demonstrated for the angular position control of a DC servo system by comparing the response with the internal model control technique. It is observed that the desired response specifications are achieved even when the lower order controller is used, thereby revealing the advantages of the proposed technique. Further, the proposed technique exhibits significant improvement in time response over the existing IMC technique. The simulation results provide a validation to the strength of the proposed technique.