Download
cs230 project mobility in energy harvesting wireless sensor network n.
Skip this Video
Loading SlideShow in 5 Seconds..
CS230 Project Mobility in Energy Harvesting Wireless Sensor Network PowerPoint Presentation
Download Presentation
CS230 Project Mobility in Energy Harvesting Wireless Sensor Network

CS230 Project Mobility in Energy Harvesting Wireless Sensor Network

143 Views Download Presentation
Download Presentation

CS230 Project Mobility in Energy Harvesting Wireless Sensor Network

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. CS230 ProjectMobility in Energy HarvestingWireless Sensor Network Nga Dang, Henry Nguyen, Xiujuan Yi

  2. What is our project? Motivation: Wireless Sensor Network - Sensor nodes are powered by batteries - High maintenance cost - Unreliability: network is disconnected when nodes are out of battery Energy Harvesting WSN - Powered by a centralized energy harvesting source whose energy is delivered to sensor nodes by robot - Advantage: + Green computing + Autonomous system + Low maintenance cost Battery System Model Energy Harvesting System Model

  3. What have other groups done? Application • Energy-Efficient Approaches in WSN • Hardware layer: energy-efficient circuit, redundant deployment _ Network layer: energy-efficient routing protocol and network topology _ Operating system: dynamic voltage scheduling, duty cycling _ Application layer: energy-efficient quality-aware data collection, multi-version applications • Use robot mobility as data collector • Robot is scheduled to visit sensor nodes, collecting data in close range • Goal: prolong system’s lifetime • reduce transmission energy for sensor nodes (shorter range) • Find a shortest path to minimize travelling energy • Avoid buffer flow at sensor node’s data buffer, deliver data in time • Usually modeled as Travelling Salesman Problem with additional constraints Operating system Network layer Hardware layer

  4. What have other groups done? (cont.) • Use robot mobility as energy deliverer • Robot is equipped with a large capacity battery • Sensors’ nodes batteries are monitoring periodically • Every hour k nodes with least remaining energy are chosen and robot will visit and charge these nodes through wireless transfer • Prolong system lifetime by charging extra battery • Disadvantage: • System lifetime extension is limited by robot’s battery capacity • Maintenance cost: changing robot battery

  5. How does our system work? Send Energy Requests Sensor Nodes Sensor Nodes Sensor Nodes Execute plan: Visit nodes and recharge batteries Base Station Report charging status Robot Collect Energy Requests &Run algorithm to schedule charging activity Send schedule to robot

  6. The charging algorithm If the robot can’t visit all the node. - It should find the maximum subset of nodes it can visit and give the shortest path of that subset. Input to TSP: D[i]: Deadline of each sensor node C[i,j]: Time to travel from node i to node j W[i]: Waiting time at each node i to charge Input: Energy request queue: sensor deadline Find a starting time satisfy both energy and timing constraints Travelling Salesman Problem Output: A sequence of sensor nodes which robot had to visit Input: Robot charging status Robot speed & power consumption & energy harvesting profile

  7. 1.5 hours 4 hours 2 hours 2 hours 2 hours 1 hour 1 hour 1 hour Charging algorithm example 12:00 7:30 13:15 21:00 0.5 hour charging 23:00 6:10 0.5 hour charging 8:00 9:30 leave base station at 5:00 get back at 23:40