CRONE Control: Principle, synthesis, performances with non-linearities and robustness-input immunity dilemma

The area of this paper concerns the robustness of stability degree, and more particularly the robustness of the damping of the control versus the parameters of the plant. The approach of the CRONE Control is presented as resulting from the non integer order differential equation which represents the dynamic model directing a natural robust relaxation. A frequency illustration of robustness is given in the Nickol-Black plane through an open loop frequency template. Such a template is synthesized by means of a CRONE variable phase regulator from the phase diagram of an agricultural mobile robot using a highly non linear error detector. The corresponding robustness performances are presented. At last, a dilemma is established by considering two templates of different lenghts. The imput of the plant is given for step responses to the reference input. It shows that the greater the robustness, the lower the input immunity.