Control Methods
Control methods in control theory can be classified into several categories based on various criteria, each reflecting different approaches to managing dynamic systems.
One of the primary distinctions is between model-based and model-free control strategies. Model-based control relies on mathematical representations of the system, utilizing models that describe the dynamics and behavior of the system under various conditions. This approach allows for precise predictions and adjustments based on the system’s expected performance. In contrast, model-free control does not require an explicit model of the system. Instead, it focuses on using real-time data or learning from interactions with the environment, making it particularly useful in situations where the system is too complex to model accurately or where the model is unknown. Moreover, there are new control methods that utilize the nominal model of the system while also incorporating real-time data to enhance the performance of the control system by integrating both model-based and data-driven approaches.
Furthermore, model-based control methods can also be categorized as linear or nonlinear. Linear control methods are based on linear models that describe the system’s behavior, which simplifies the analysis and design of control systems. These methods are often easier to implement and understand, making them suitable for a wide range of applications where system dynamics can be approximated as linear. On the other hand, nonlinear control methods are designed to handle systems exhibiting complex behaviors that cannot be accurately captured by linear equations. Nonlinear control techniques are essential for managing systems with inherent nonlinearities, such as saturation, hysteresis, or varying operational conditions, and they often require more sophisticated mathematical tools and approaches.
A summary of the different control methods (control strategies) is shown in the following figure. It is worth noting that there are various combinations of these control methods found in the literature.
Download the high-resolution file of the diagram from here.
Download the pdf file of the diagram with reference links to the control methods from here.
