Control Systems with Input and Output Constraints

In current industrial control, PID technology is firmly established as the standard. Often, however, high control loop performance can only be obtained within narrow limits around a given steady-state operating point. If perturbations introduced by any reference or load change are outside these limitations then the actuators will constrain the system inputs. Other operational limits may also be imposed by additional variables within the plant producing output constraints. A typical method of dealing with input and output constraints, especially for PID control, has been the empirical design and implementation of an intuitive solution to an individual plant and its constraints. Such ad hoc solutions perform surprisingly well but often remain in the form of isolated practical know-how without a more general scientific basis. Control Systems with Input and Output Constraints develops this empirical approach by demonstrating how particular answers to particular industrial design problems can be systematized to cope with a wide variety of simple and more complex situations. Each class of design problems is presented in five parts: industrial situation; problem statement; currently available control structures; benchmark simulation to obtain typical transient response and nonlinear stability analysis to relate structure to response. Links to optimal control and model predictive control are also explored. These steps help the reader to learn how to choose or adapt a control architecture and design or analyse it on a systematic basis.   Features: associated website contains many ready-made examples and case studies using MATLAB®/Simulink® to which extensive reference is made throughout the text facilitating understanding and saving time; exercises interspersed throughout each chapter that allow the student to confirm progress as he/she proceeds; logical five-step design procedure for each problem class moving from a particular industrial example to the informed choice of generic controller and the preparation of closed loop analysis.   Control Systems with Input and Output Constraints will be of great benefit to advanced students of control looking to pursue a career in process and/or plant control or in applications-oriented research. The practical basis of the presentation, the systematic design procedure, the restraint on mathematical formalism and emphasis on implementability will also appeal to industrial control engineers.