Energy efficient time-triggered control over wireless sensor/actuator networks

Vineeth S. Varma (1) , Romain Postoyan (1)

1 CRAN - Centre de Recherche en Automatique de Nancy

We investigate the scenario where a controller is connected to a plant using a wireless network. Our objective is to design control strategies, which efficiently use the network in terms of energy, by taking into account the fluctuations of the wireless channel. In particular, we consider discrete-time systems and we focus on time-triggered control. That is, we assume that we know a controller, which ensures a desired property (such as stability), as long as two successive transmissions are not spaced by more than a fixed number of steps N. The problem formulation is generic in the sense that we do not make any assumption on the plant and the controller structures or properties, all we need to ensure is the constraint on the transmission times. We then present triggering strategies to minimize the energy expenditure based on knowledge on the channel state, while ensuring that two successive transmissions are not spaced by more than N steps. The results demonstrate that periodically communicating after exactly N time instants has passed (to minimize the number of transmissions), is not always the optimal scheme to minimize the energy cost. As a result of certain properties of the wireless channel, communicating more often when the wireless channel conditions are good, results in a smaller energy consumption overall despite a higher frequency of communication. Numerical results confirm the validity of the approach and show that a significant amount of energy can be saved.

Mots clés: Networked control systems; Wireless network; Time-triggered control

Domaines: Automatique / Robotique

Vineeth S. Varma, Romain Postoyan. Energy efficient time-triggered control over wireless sensor/actuator networks. 55th IEEE Conference on Decision and Control, CDC 2016, Dec 2016, Las Vegas, NV, United States. ⟨10.1109/CDC.2016.7798674⟩. ⟨hal-01379966⟩