Self-triggered control of multiple loops over IEEE 802.15.4 networks
2011 (English)In: IFAC Proceedings Volumes: (IFAC-PapersOnline), 2011, no PART 1, 13893-13898 p.Conference paper (Refereed)
Given the communication savings offered by self-triggered sampling, it is becoming an essential paradigm for closed-loop control over energy-constrained wireless sensor networks (WSNs). The understanding of the performance of self-triggered control systems when the feedback loops are closed over IEEE 802.15.4 WSNs is of major interest, since the communication standard IEEE 802.15.4 is the de-facto the reference protocol for energy-efficient WSNs. In this paper, a new approach to control several processes over a shared IEEE 802.15.4 network by self-triggered sampling is proposed. It is shown that the sampling time of the processes, the protocol parameters, and the scheduling of the transmissions must be jointly selected to ensure stability of the processes and energy efficiency of the network. The challenging part of the proposed analysis is ensuring stability and making an energy efficient scheduling of the state transmissions. These transmissions over IEEE 802.15.4 are allowed only at certain time slots, which are difficult to schedule when multiple control loops share the network. The approach establishes that the joint design of self-triggered samplers and the network protocol 1) ensures the stability of each loop, 2) increases the network capacity, 3) reduces the number of transmissions of the nodes, and 4) increases the sleep time of the nodes. A new dynamic scheduling problem is proposed to control each process, adapt the protocol parameters, and reduce the energy consumption. An algorithm is then derived, which adapts to any choice of the self-triggered samplers of every control loop. Numerical examples illustrate the analysis and show the benefits of the new approach.
Place, publisher, year, edition, pages
2011. no PART 1, 13893-13898 p.
, IFAC Proceedings Volumes (IFAC-PapersOnline), ISSN 1474-6670 ; 18
IEEE 802.15.4, NCS, Self-triggered control, Wireless sensor network, Closed-loop control, Communication standards, Control loop, Dynamic scheduling problems, Energy efficient, Energy-constrained, Energy-Efficient Scheduling, Feed-back loop, IEEE 802.15.4 networks, Joint designs, Multiple control loops, Multiple loops, Network Capacity, Numerical example, Protocol parameters, Reference protocols, Sampling time, Sleep time, Time slots, Wireless sensor network (WSNs), Energy efficiency, Energy utilization, Network protocols, Numerical analysis, Scheduling, Sensor nodes, Standards, Wireless sensor networks, Process control
IdentifiersURN: urn:nbn:se:kth:diva-149780DOI: 10.3182/20110828-6-IT-1002.03604ScopusID: 2-s2.0-84866769492ISBN: 9783902661937OAI: oai:DiVA.org:kth-149780DiVA: diva2:741957
18th IFAC World Congress; Milano, Italy, 28 August - 2 September, 2011
QC 201408282014-08-292014-08-272014-10-03Bibliographically approved