Wyniki wyszukiwania - BazTech

1

The look-up algorithm of monitoring an object described by non-linear ordinary differential equations

Hawro Przemysław, Kwater Tadeusz, Bartman Jacek, Kwiatkowski Bogdan

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2023

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Vol. 71, nr 2

art. no. e144603

EN

The article proposes an adaptive algorithm that generates all object signals, including those for which measurements are not performed due to the difficulties associated with on-line measurements. The algorithm is modeled on the idea of the Kalman filter using its equation, however, the selection of gains is optimized in a different way, i.e. the constant values depend on the adopted ranges of adaptation errors. Moreover, the knowledge of the statistics of all noise signals is not imposed and there is no linearity constraint. This approach allowed to reduce the complexity of calculations. This algorithm can be used in real-time systems to generate signals of objects described by non-linear differential equations and it is universal, which allows it to be used for various objects. In the conducted research, on the example of a biochemically contaminated river, only easily measurable signals were used to generated the object signals, and in addition, in the case of absence some measurements, the functioning of the algorithm did not destabilize.

2

Research on improved sparrow search algorithm for PID controller parameter optimization

Zhang Mingfeng, Xu Chuntian, Xu Deying, Ma Guoqiang, Han Han, Zong Xu

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2023

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Vol. 71, nr 6

art. no. e147344

EN

PID controllers are crucial for industrial control because of their simple structure and good robustness. In order to further improve the accuracy of PID controllers, this paper proposes an improved sparrow search algorithm (ISSA) to prevent the problem of the algorithm being prone to falling into the local optimum at the late stage of iteration. Based on the standard sparrow search algorithm, the position update formula and the step size control parameter are optimized to help quickly jump out of the local, and to obtain the optimal solution in the whole domain. Finally, to verify the accuracy and stability of the improved algorithm, nine standard test functions are first simulated. Then, the PID parameter optimization tests are finished with the chilled water and battery charging systems, where the lifting load and applying perturbation are carried out. Both the simulation and test results show that ISSA improves the convergence speed and accuracy, and performs better in terms of stability.

3

Controlling the mean arterial pressure by modified model reference adaptive controller based on two optimization algorithms

Haamed Rawaa, Hameed Ekhlas

Applied Computer Science

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2020

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Vol. 16, no 2

53--67

EN

This paper Presents Modified Model Reference Adaptive Controller (MRAC) to regulate the hight blood pressure. It is based on slate model that repre-sent the mathematical equation that clarifies relationship between blood pressure and vasoactive drug injection. In this work Squirrel Search Algo-rithm (SSA) and Grey Wolf Optimizer (GWO) algorithms are considered to optimize the controller parameters. the results showed that the suggested controller has good performance and stabilize the mean arterial pressure with small settling time (below than 400s) and small overshoot (below than 1 mmHg) with low amount of error.

4

Accelerating backtrack search with a best-first-search strategy

Mann Z. Á., Szép T.

International Journal of Applied Mathematics and Computer Science

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2014

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Vol. 24, no. 4

901--916

EN

Backtrack-style exhaustive search algorithms for NP-hard problems tend to have large variance in their runtime. This is because “fortunate” branching decisions can lead to finding a solution quickly, whereas “unfortunate” decisions in another run can lead the algorithm to a region of the search space with no solutions. In the literature, frequent restarting has been suggested as a means to overcome this problem. In this paper, we propose a more sophisticated approach: a best-first-search heuristic to quickly move between parts of the search space, always concentrating on the most promising region. We describe how this idea can be efficiently incorporated into a backtrack search algorithm, without sacrificing optimality. Moreover, we demonstrate empirically that, for hard solvable problem instances, the new approach provides significantly higher speed-up than frequent restarting.

5

Parallel and distributed Controlled Random Search algorithms; case study results

Marks M., Niewiadomska-Szynkiewicz E.

Prace Naukowe Politechniki Warszawskiej. Elektronika

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2006

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z. 156

263-272

EN

CRS (Controlled Random Search) algorithms for global optimization are considered. The main objective is to present the advantages of developing the parallel and distributed random search algorithms to search for the global solution. A practical example, application of parallel CRS2, CRS4, CRS6, CRSI algorithms and distributed CRS2 algorithm to calculate the optimal prices of products that are sold in the market, are presented. In the final part of the paper the results of numerical experiments performed on the historical data are described and discussed.