1 / 15

Decentralized and Dynamic Bandwidth Allocation in Networked Control Systems

Decentralized and Dynamic Bandwidth Allocation in Networked Control Systems. Ahmad T. Al-Hammouri, Michael S. Branicky, Vincenzo Liberatore Case Western Reserve University Stephen M. Phillips Arizona State University April 25, 2006

keziah
Download Presentation

Decentralized and Dynamic Bandwidth Allocation in Networked Control Systems

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Decentralized and Dynamic Bandwidth Allocation in Networked Control Systems Ahmad T. Al-Hammouri, Michael S. Branicky, Vincenzo Liberatore Case Western Reserve University Stephen M. Phillips Arizona State University April 25, 2006 Support by: NSF CCR-0329910, Department of Commerce TOP 39-60-04003, NASA NNC04AA12A, and an OhioICE Training grant`

  2. Paper Overview • Control over Networks • NCSs, DCSs, SANETs, … • Control of Networks • Efficient BW allocation • Congestion control • Fairness • We propose a “Cof N” scheme to better serve “Cover N” Decentralized and Dynamic Bandwidth Allocation in Networked Control Systems (WPDRTS’06)

  3. Control over Networks Decentralized and Dynamic Bandwidth Allocation in Networked Control Systems (WPDRTS’06)

  4. Control over Networks Decentralized and Dynamic Bandwidth Allocation in Networked Control Systems (WPDRTS’06)

  5. Control over Networks • Remote interaction (monitoring & control) with the physical world • Applications: • Industrial automation & process control • Space exploration, e.g., telerobotics • Smart homes • Medical sensing & surgical simulations • Automatic asset mgmt. (RFID) Decentralized and Dynamic Bandwidth Allocation in Networked Control Systems (WPDRTS’06)

  6. Control of Networks (Scope of the paper) • A bandwidth allocation scheme • Objectives: • Stability of control systems • Efficiency & fairness • Fully distributed, asynchronous, & scalable • Dynamic & self reconfigurable • Formulating the scheme in CT • NCSs regulate h based on congestion fed back from the network Decentralized and Dynamic Bandwidth Allocation in Networked Control Systems (WPDRTS’06)

  7. Sampling Rate & Network Congestion h=1/r l2 l1 Decentralized and Dynamic Bandwidth Allocation in Networked Control Systems (WPDRTS’06)

  8. Problem Formulation • Define a utility fn U(r) that is • Monotonically increasing • Strictly concave • Defined for r ≥ rmin • Optimization formulation Decentralized and Dynamic Bandwidth Allocation in Networked Control Systems (WPDRTS’06)

  9. Distributed Implementation p p p • Two independent algorithms • End-systems (plants) algorithm • Router algorithm (later on) NCS Plant NCS Controller Router Decentralized and Dynamic Bandwidth Allocation in Networked Control Systems (WPDRTS’06)

  10. NCS-AQM Control Loop Model Plant P(s) = Queue ControllerG(s) NCS Plant Queue f(q(t)) q`=Σr(t) - C p(t) q(t) tf tb Decentralized and Dynamic Bandwidth Allocation in Networked Control Systems (WPDRTS’06)

  11. Queue Controller G(s) q0 q(s) e u G(s) P(s) _ + • Proportional (P) Controller • GP(s) = kp • Proportional-Integral (PI) Controller • GPI(s) = kp+ ki/s Decentralized and Dynamic Bandwidth Allocation in Networked Control Systems (WPDRTS’06)

  12. Determination of kpand ki • Stability region in the ki–kp plane • Stabilizes the NCS-AQM closed-loop system for delays less or equal d • Analysis of quasi-polynomials, f(s,es) Decentralized and Dynamic Bandwidth Allocation in Networked Control Systems (WPDRTS’06)

  13. Simulations & Results 50 NCS Plants: [Branicky et al. 2002] [Zhang et al. 2001] Decentralized and Dynamic Bandwidth Allocation in Networked Control Systems (WPDRTS’06)

  14. Simulations & Results (cont.) PI ¤ P ¤ Decentralized and Dynamic Bandwidth Allocation in Networked Control Systems (WPDRTS’06)

  15. Thank You • Questions • Comments • Probing further: http://start.case.edu/~vxl11/NetBots Decentralized and Dynamic Bandwidth Allocation in Networked Control Systems (WPDRTS’06)

More Related