Controle por modo deslizante para sistemas com atrasos de comunicação estocásticos

Abstract

This work proposes the use of a state observer in order to compensate stochastic time-delays in a sliding mode control system. The proposed strategy is able to compensate the delays and provide the controller the state estimates in continuous time. Signals from sensors located in the plant are periodically sampled and sent over a network to the state observer. The networked induced delays are considered as known and they vary stochastically. Furthermore, in the stability analysis, the concept of almost sure stability is used, which provides a very satisfactory and less conservative result. Thus, combining known techniques with new methodologies, a good result is obtained in compensating delas with stochastic characteristics. Illustrative examples are presented throughout this study, simulating normal operating conditions and conditions that aim to stress and reinforce the importance of delay compensation in the case of sliding mode controllers.