Modern methods of design, analysis, optimization and implementation of conventional control algorithms for processes with finite and infinite degrees of freedom

This paper presents characterization methods for a large class of industrial processes using a critical experiment as well as modern methods of design, analysis, optimization and implementation of conventional control algorithms. Special attention is set to the process characterization methods using relay techniques and phase-locked loops in order to form a general process model which serves as a base for controller adequate design. This general process model adequately approximates processes which behavior can be described with linear mathematical models with finite and infinite degrees of freedoms including conventional finite dimension systems, time-delayed systems, systems whose behavior is dominated by a wave and transport problems such as mass and energy transfer, systems described with fractional differential equations etc. Based on characterization, an important accent is also put on the design of PI/PID controller due to their large application in industry which exceeds 93% compared to all the other regulators according to Honeywell's surveys. In order to illustrate validity of characterization model and effectiveness of presented design method, the paper provides an example of optimal designed PID controller under constraints on robustness and sensitivity to the measurement noise. Digital implementation is considered for both controllers with rational and those with non-rational transfer functions. At the end, analytical design methods of controllers are elaborated and analytical tuning formulae for PI/PID controllers are presented.