Time-delay estimation and finite-spectrum assignment for control over multi-hop WSN

Emmanuel Witrant (1) , Pangun Park (2) , Mikael Johansson (2)

1 GIPSA-SLR - GIPSA - Systèmes linéaires et robustesse
2 KTH - KTH Royal Institute of Technology [Stockholm]

Recent technological developments and the need for global control strategies to meet with stringent performance requirements rendered the use of wireless sensor networks (WSN) of prime importance for today's automation. Such communication devices heavily affect the information transport, especially when a multi-hop configuration is introduced to minimize the energy consumption of the network. The associated time-delays are strongly varying and necessitate the design of a dedicated control approach for remote regulation, as proposed in this chapter. First, the communication process is analyzed and illustrated with the Breath protocol, which results in a description of the delay in the frequency domain. Such analysis motivates the use of a CUMSUM Kalman filter to estimate the delay from round-trip-time (RTT) measurements while selecting the desired frequencies. This estimation then allows for the setup of a state-predictor that ensures a finite spectrum assignment (FSA) on the closed loop spectrum. The efficiency of this approach and the impact of packet losses is finally investigated on an inverted pendulum using experimental network measurements.

Mots clés: Network controlled systems; Wireless networks; Multi-hop networks; Time-delay estimation; Predictive control; Finite spectrum assignment

Domaines: Automatique / Robotique

Emmanuel Witrant, Pangun Park, Mikael Johansson. Time-delay estimation and finite-spectrum assignment for control over multi-hop WSN. Mazumder, Sudip K. (Ed.). Wireless Networking Based Control, Springer, pp.135-152, 2011, ISBN 978-1-4419-7392-4, e-ISBN 978-1-4419-7393-1. ⟨10.1007/978-1-4419-7393-16⟩. ⟨hal-00667148⟩