Slide 1Adaptive controlAdaptive control diagramSlide 41.2 Adaptive Control Versus Conventional Feedback ControlSlide 6Slide 7Slide 8Slide 9Slide 10Slide 111.2.1 Fundamental Hypothesis in Adaptive ControlSlide 131.2.2 Adaptive Control Versus Robust ControlSlide 15Slide 16THANK YOU1.1 ADAPTIVE CONTROLADAPTIVE CONTROL•Adaptive control is a method of controlling a process or system that changes its behavior over time in response to changes in its environment or operating conditions.•It covers a set of techniques which provide a systematic approach for automatic adjustment of controllers in real time, in order to achieve or to maintain a desired level of control system performance when the parameters of the plant dynamic model are unknown and/or change in time.ADAPTIVE CONTROL DIAGRAM•In order to design and tune a good controller, one needs to:(1)Specify the desired control loop performances.(2) Know the dynamic model of the plant to be controlled.(3) Possess a suitable controller design method making it possible to achieve thedesired performance for the corresponding plant model.1.2 ADAPTIVE CONTROL VERSUS CONVENTIONAL FEEDBACK CONTROL•The unknown and unmeasurable variations of the process parameters degrade theperformances of the control systems. Similarly to the disturbances acting upon thecontrolled variables, one can consider that the variations of the process parametersare caused by disturbances acting upon the parameters (called parameter distur-bances). These parameter disturbances will affect the performance of the controlsystems. Therefore the disturbances acting upon a control system can be classifiedas follows:•(a) disturbances acting upon the controlled variables;•(b) (parameter) disturbances acting upon the performance of the control system.•An adaptive control system measures a certain performance index (IP) of the control system using the inputs, the states, the outputs and the known disturbances. From the comparison of the measured performance index and a set of given ones, the adaptation mechanism modifies the parameters of the adjustable controller and/or generates an auxiliary control in order to maintain the performance index of the control system close to the set of given ones (i.e., within the set of acceptable ones).•Basic configuration for an adaptive control system is not monitored) under the effect of parameter disturbances (the design is done assuming known and constant process parameters). An adaptive control system, which contains in addition to a feedback control with adjustable parameters a supplementary loop acting upon the adjustable parameters of the controller, will monitor the performance of the system in the presence of parameter disturbances.1.2.1 FUNDAMENTAL HYPOTHESIS IN ADAPTIVE CONTROL•The operation of the adaptation loop and its design relies upon the following fundamental hypothesis: For any possible values of plant model parameters there is a controller with a fixed structure and complexity such that the specified performances can be achieved with appropriate values of the controller parameters. In the context of this book, the plant models are assumed to be linear and the controllers which are considered are also linear. Therefore, the task of the adaptation loop is solely to search for the “good” values of the controller parameters.1.2.2 ADAPTIVE CONTROL VERSUS ROBUST CONTROL•In the presence of model parameter variations or more generally in the presence ofvariations of the dynamic characteristics of a plant to be controlled, robust controldesign of the conventional feedback control system is a powerful tool for achievinga satisfactory level of performance for a family of plant models. This family is oftendefined by means of a nominal model and a size of the uncertainty specified in theparameter domain or in the frequency domain.Comparison of conventional feedback control and robust control, (a) conventional designfor the nominal model, (b) robust control designTHANK