Modified active disturbance rejection control scheme for systems with time delay

Active disturbance rejection control (ADRC) has been gaining attention in recent years and shown its performance multiple applications including non-linear ones, without the need of accurate models. Despite good results this technique, time delay can deteriorate ADRC, limiting application. Here, effect on stability a linear ADRC is analysed, using an alternative mathematical description, new effective design based modified scheme, proposed to overcome while maintaining properties ADRC. An experimental example discussed considering system with low damped mechanical resonances, showing technique.