Eckhard, D, Bergel ME, Bazanella AS.
2010.
Análise comparativa dos métodos de ajuste de controladores baseados em dados. XVIII Congresso Brasileiro de Automática. :1620–1626., Bonito: SBA
AbstractThis work addresses data-based control design. The properties inherent to data-based design are discussed under a common theoretical framework. The computational cost is estimated with relation to memory space and number of elementar operations. Simulations present a comparision between the studied methods.
Eckhard, D, Campestrini L, Boeira E, Gomes da Silva Jr. JM.
2014.
Aplicação de métodos de controle baseado em dados em um sistema de controle de nível industrial. XVI Congreso Latinoamericano de Control Automático. :1410–1415., Cancún: AMCA
AbstractOs métodos de projeto de controladores baseado em dados são um conjunto de técnicas utilizadas para ajustar os ganhos de controladores, que não utilizam um modelo matemático do processo na sintonia dos parâmetros. Alguns destes métodos são o Iterative Feedback Tuning (IFT), Correlation based Tuning (CbT), Virtual Reference Feedback Tuning (VRFT) e Optimal Controller Identification (OCI). Apesar de algumas destas t{ écnicas existirem por mais de uma década, são encontrados poucos trabalhos na literatura que demonstram a aplicabilidade dos métodos em sistemas industriais. Neste trabalho duas técnicas de projeto de controladores baseado em dados não-iterativas (VRFT e OCI) são aplicadas em em um sistema de controle de nível industrial, que utiliza uma rede Foundation Fieldbus H1. O trabalho demostra que as técnicas apresentadas podem ser aplicadas com facilidade em sistemas industriais gerando repostas dinâmicas satisfatórias.
Scheid Filho, R, Eckhard D, Gonçalves da Silva GR, Campestrini L.
2016.
Application of Virtual Reference Feedback Tuning to a non-minimum phase pilot plant, Sept. 2016 IEEE Conference on Control Applications (CCA). :1318–1323., Buenos Aires: IEEE
AbstractVirtual Reference Feedback Tuning (VRFT) is a data-driven technique used to design controllers without the need of a process model, only input-output data is utilized. When the process has non-minimum phase (NMP) zeros, the original method usually presents poor performance, because scarcely the reference model has the same NMP zeros as the process. To overcome this problem, a flexible criterion has been proposed to the VRFT method, in a way that both the controller parameters and the NMP zeros of the process are estimated together. In this paper we present the application of the VRFT method with flexible criterion to the level control of a MIMO pilot plant. We show that a sequential controller design may incorporate NMP behavior to the process. We then use the VRFT method with flexible criterion to design the controller using only closed-loop data from the process.
Müller, I, Winter JM, Pereira CE, Netto JC, Eckhard D.
2014.
Automatic {RF} power adjustment for {WirelessHART} field devices. 2014 IEEE International Conference on Industrial Technology. :749–753., Busan: IEEE
AbstractIndustrial wireless networks are gradually being adopted in industry, especially due to the low installation costs and low maintenance provided by these systems. For the use in harsh environments, the communication system should provide reliable radio links and low power to allow battery powered devices. In this context, WirelessHART, ISA SP100.11a and WIA-PA protocols were developed to meet these requirements. The standards of these protocols define a minimum number of RF fixed power and selectable only by commissioning. Within this scenario, it is important to adapt RF power modulation, a procedure already used in several communication protocols to minimize the energy consumption of transceivers while maintaining link quality. In this paper, three ways to modulate RF power are analyzed within WirelessHART field devices. A specific approach that works in a decentralized way is developed and the results show it can save 50% of energy in certain cases. The proposal has the extra advantage to be compatible with the standard.
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