Process control problem-solving strategies

The second part of the work concerns task analysis. It aims first at recognizing the different variables observed by the operator in order to perform supervisory tasks. To carry out this analysis, it is necessary to study the operator s activities in the control room in order to identify his needs and the different problem solving strategies he can use [6]. This analysis must also emphasize the tetiqxnal constraints associated with performing supervisory task. So, the first step, which includes a study of the process and an analysis of the supervisory task constitutes a preliminary work meant to get the interface designer used in the different aspects of the process application, and lead him to defining the functionalities of the interface which needs to be developed. 

In contrast to the sequential solution method, the simultaneous strategy solves the dynamic process model and the optimization problem at one step. This avoids solving the model equations at each iteration in the optimization algorithm as in the sequential approach. In this approach, the dynamic process model constraints in the optimal control problem are transformed to a set of algebraic equations which is treated as equality constraints in NLP problem [20], To apply the simultaneous strategy, both state and control variable profiles are discretized by approximating functions and treated as the decision variables in optimization algorithms. 

There are two basic approaches to problem solving (1) find and correct the problem, applying only the controls needed or (2) overcome the problem with an appropriate process control strategy. The approach one selects depends on the nature of the processing problem, and whether enough time and money are available to correct it. Process controls may, in most cases, provide the most economical solution. To make the right decision, one must systematically measure the magnitude of the disturbances, relate them to product quality, and identify their cause so that proper control action can be taken. 

Insights from nonlinear wave theory can also be used for designing new control strategies. A major problem in controlling product purities in separation as well as integrated reaction separation processes is often the lack of a cheap, reliable and fast online concentration measurement. This problem can be solved in two different ways (i) through simple inferential control, or (ii) model-based measurement. 

Membrane technology is also an ideal technology for application in the space because process intensification strategy is a more imperative request in the space than on the Earth, today. Volumetric efficiency, optimal remote control, energy, and waste saving are fundamental aspects in the space. Membranes could efficiently solve some of the problems of life in the space such as energy production and water and air purification, fulfilling these requirements. 

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