The main purpose of this work is to provide an extensive, simulation-based comparison of robustness of PID and MPC algorithms in control of blood glucose levels in patients with type 1 diabetes and thus answer the question of their safety. Cohort testing, with 1000 simulated, randomized patients allowed to analyze specific control quality indicators, such as number of hypoglycemic events, and length of hypo- and hyperglycemia periods. Results show that both algorithms provide a reasonable safety level, taking into account natural changes of patients’ physiological parameters. At the same time, we point out drawbacks of each solution, as well as general problems arising in close-loop control of blood glucose level.

The paper presents a solution to the problem of synthesis of control with respect to the sliding interval length for the optimization of a class of discrete linear multidimensional objects with a quadratic performance criterion. The equation of motion of a closed multidimensional discrete system in the general non-stationary case is derived based on the length of the optimization interval and their main properties. The closed-loop is fitted with a signal representing the predicted values averaged over the whole sliding interval of optimization with a certain weight. A problem with a sliding optimization interval may not require a real-time solution by means of a sequence of solutions on compressed intervals. Therefore, the study of control systems with optimization on a sliding interval is of undoubted interest for a number of practically important control problems.

The aim of this work is to study the influence of closed loop control on diagnostic indices of both broken bar and mixed air-gap eccentricity fault indices of the squirrel cage induction motor drive. The present work is focused on the direct stator current isd signal analysis, which is independent of torque load when the induction motor is controlled by an indirect control field. The fault signatures are on the line extracted from the direct stator current signal using the discrete Fourier transformation (DFT). The formula of the measured direct stator current at both conditions is determined by the transfer function of the current loop. The obtained results show that the current loop corresponds to a low pass filter and can reduce the magnitude of diagnostic indicators which lead to wrong evaluation of the fault. Simulation and experiments were carried out in order to confirm the theoretical analysis.