Analysis of the Synthesis of a Feedback-Feedforward Control System with a Model of Unstable, Non-minimal Phase and Time-Delay Objects

The paper fully analyzes the proposed mechanism for synthesizing a robust control system. The equivalence, popular in recent years, of the MFC structure and the classical FB-FF structure was demonstrated. Using the example of the second structure, the process of synthesis of the control system is discussed in detail and shown, along with its impact on the nature of the obtained system. Considerations of the presented control system synthesis mechanism cover a wide spectrum of control object dynamics from classical, through non-minimum phase, time delay and unstable. All theoretical considerations are supported by simulation results of exemplary control systems. Also presented is a variant of synthesis that allows reducing the impact of the limitation of the disturbance dynamics of the control system by the dynamics of the object. As an interesting feature, a phenomenon occurring for high-speed loop structures with feedback is presented, which makes it possible to reverse the synthesis mechanism and directly take into account the influence of controllers dynamic.