Bridging the gap between advanced control methods and industrial control applications: Shortcomings of the current nonlinear PID Method and new research lines to its enhancing

As the performance requirements become more demanding and the plants become more and more complex, control designers were naturally forced to look beyond traditional linear control theory and attempt to find more advanced nonlinear methods. However, it has been very difficult to overcome the huge gap between the current knowledge, researched by the scientific automatic control community, and its application in the industrial environment. In this paper, it is proposed to consider the nonlinear PID as the method to deal with this hitch. The current nonlinear PID methodologies were reviewed and their shortcomings presented. The main aim is to objectify new research lines that may enhance it, in order to ensure that the evolution of industrial control systems is strongly linked to that of the control techniques.