Jan Siroky

Constrained Active Fault Detection and Control

The technical note introduces a constrained optimization approach to active fault detection and control. Detection and control aims can be expressed either as a part of an objective function or as a constraint. Five principal formulations of active fault detection and control problem are proposed and investigated in the technical note. Three formulations are focused on alternative detection and control aims combinations while the other formulations represent marginal cases that outline a relationship to the well know fields of optimal control and active fault detection. The underlying difficulty of the optimal solution is discussed and a suboptimal solution is proposed that makes use of nonlinear programming techniques.

Model predictive control of buildings: The efficient way of heating

The implicit model predictive control based on models identified by subspace identification methods was implemented and tested on a large university building. The control was improved by incorporating the weather prediction into the model. The performance of said controller was estimated in an experiment, wherein two almost identical building blocks were compared - one controlled by the model predictive control, and the other one by the existing weather-compensated heating controller. The model predictive control achieved energy consumption lower by approximately 10 %. Based on the positive results, an implementation was developed, which is suitable for commercial applications.

An optimization approach to resolve the competing aims of active fault detection and control

The paper deals with the problem of active fault detection and control for multiple models. It is assumed that a fault detector is given and the goal is to design an input signal generator such that detection and control aims are achieved. Since these two aim are conflicting, it is necessary to express a desired compromise between them. The paper investigates three formulations that allow for respecting both competing aims. In the first formulation both aims are combined into a single criterion. In other two formulations, one aim is reflected in the criterion and the other aim is enforced as a constraint.

Model of a hot water full circulation mode in a building

The circulation system of the heating water can be used for distribution of heat throughout a building even without an active heat supply - the water may absorb the heat in the rooms exposed to the solar heat and deliver it to the rooms in shade. In Central Europe, this is particularly useful when the outdoor temperatures are close to the required inside temperatures and solar energy can play a significant part in the building heating system. The model of the circulation system during a full circulation mode can help the heating system operators to predict the possible effect of said system and thus save the energy. The model was identified by means of subspace identification methods and connected to a Kalman filter.

Optimal active decision making for control

The paper deals with a general formulation of the optimal active change detection and control problem for stochastic systems, which includes several design problems as special cases. The special case treated in this paper can be characterized as a decision making problem where decisions are transformed into inputs of a system and the aim is to control the system. The utilization of the general formulation naturally leads to an optimal solution that makes use of the closed loop information processing strategy. Since the optimal solution is computationally intractable, the paper also discusses some approximate design techniques available for obtaining a feasible active generator for a given controller. The results are illustrated in a numerical example.

Application of knowledge-based control on an antibiotics production fermentation process

Modernisation of control systems of industrial biotechnology processes to the current technology levels presents a challenging task because nowadays, there is a bigger stress put on the automatisation of the production process so that the possible human fault is minimised. Therefore in this paper, the process of sequential modernisation of the control system from “almost fully controlled by process operators” to “almost supervised control” is presented. A decision support system based on various knowledge about the process is developed to support actions performed by process operators. The system brings improvements in antibiotic production operations and reduces manufacturing variance.