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| Author(s): |
Eduardo Paciência Godoy
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Carlos. |
| Institution: | Universidade de São Paulo (USP). Escola de Engenharia de São Carlos (EESC/SBD) |
| Defense date: | 2011-03-21 |
| Examining board members: |
Arthur Jose Vieira Porto;
Edilson Reis Rodrigues Kato;
Newton Maruyama;
Geraldo Nunes Silva;
Mario Luiz Tronco
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| Advisor: | Arthur Jose Vieira Porto |
| Abstract | |
Networked control system (NCS) is a distributed control system where the sensors, actuators and controllers are physically separated and connected through an industrial communication network. The NCS represents the evolution of networked control architectures providing greater modularity and control decentralization, maintenance and diagnosis ease and lower cost of implementation. The challenge in the development of NCS is to overcome the degenerative effects of factors which affect its performance and stability. Among these factors are the sampling time, the loss of information on the network and the network delays. Aiming to overcome this challenge, this work presents the development of NCS for applications in CAN-Based networks based on the simulation use and in a control strategy proposal. The use NCS simulation tools, selected by a comparative and qualitative study, allowed to analyze the impact of degrading factors in the NCS control performance and stability. This analysis using simulation highlighted the message sampling time as factor with the biggest influence for the design of CAN-based NCS. To overcome the sampling time problem, an adaptive control strategy was proposed. This strategy uses the NCS output to automatically adapt the message sampling time, ensuring NCS control performance and stability and providing significant reduction of the CAN network load. Experiments carried out on a NCS Research Platform demonstrated the reliability and robustness of the adaptive control methodology application, even under worst case conditions of operation of the CAN-based network. Experiments have also proved the effectiveness of a model identification technique developed for NCS, which presents the advantage of using information available on the network to obtain the NCS model with acceptable accuracy. (AU) | |