A Cyber-Physical System for Distributed Real-Time Control of Urban Drainage Networks in Smart Cities

Transcription

1 Cyber-Physical System for Distributed Real-Time Control of Urban Drainage Networks in Smart Cities ndrea Giordano, Giandomenico Spezzano, ndrea Vinci ICR - CNR Rende (CS), Italy Giuseppina Garofalo, Patrizia Piro Dipartimento Ingegneria Civile- Indirizzo Idraulica Università della Calabria Rende (CS), Italy

2 Background Sewer system The magnitude and the frequency of flooding in urban areas are likely to increase due to climate change expanding urbanization In current practices, engineers and administrators focus their attention on flooding phenomena due to rivers inside the cities Conversely, There is not enough attention toward flooding triggered by overload conditions occurring in the sewer system (sewer flooding). Flooding phenomena give rise to potential risks to human life, economic assets and the environment, etc. 2

3 Flooding phenomenon Road surface Sewer system Drains 3

4 Flooding phenomenon Road surface Sewer system Drains 4

5 Smart Gates electronically adjustable gates. They allow you dynamically changing the flow of the water DSRT 2011, September 4-7, Salford, UK 5

6 Distributed real-time control Real time control: Reading from sensors Elaborating information (as soon as possible) ctuating on the gates Issues related on centralized control Need for comprehensive mathematical model of the whole hydraulic network Need for communication between each sensor and gate and the centralized control the huge amount of the incoming data gives rise to real time constraint violation Proposed approach: fully distributed: Computational nodes spread across the drainage network (RaspBerry) Only short-range communications are required Enabling gent-based e Swarm Intelligence 6

7 Drainage network drainage network is made up of: conduits, i.e. pipes where water flows Inlet nodes, i.e. water entry points (manhole) Outlet nodes, i.e. exit points where water is discharged into a river, lake, reservoir and so forth Junctions, i.e intersection points for conduits whole drainage network of a city can be broken down in a set of not connected tree-like structured drainage networks which own only on outlet node 7

8 Drainage network drainage network is defined in a recursive way: it is made up of a main channel into which recursively defined (sub)network discharge. The recursive process stops when reaching the Most simple Drainage Network (MSDN) made up of only a conduit and an inlet node. 8

9 Drainage network 9

10 Generated networks 10

11 Gates position The gates are inserted at the start of each branch, i.e. between the junctions of the main channel and the sub-networks 11

12 Gate-agents One agent per gate One agent per outlet node The whole problem become: «for each network, each agent has to tune its gate in order to ensure that filling levels of the conduits are balanced as much as possible» 12

13 agent algorithm agents continuously execute two tasks: Task 1: Figuring out the average of the water level in the specific network Task 2: triggering specific gates in order to bring the water level closer to that average 13

14 Task1: Gossip-based algorithm Nodes own such numerical values The goal is to compute global average even if each node is able to communicate only with neighbour nodes Each node holds the current local average value (initially sets to the measured value) These local average values are continuously exchanged among neighbor nodes which update their local averages by applying the average operator It can be proved that the algorithm converges to the global average value after an enough steps * The algorithm ensures fault tolerance and adaptivity *Jelasity M., Montresor., Babaoglu O., Gossip-based aggregation in large dynamic networks, CM Transactions on Computer Systems 23, 3, ,

15 Task2: how to tune the gate? Even though we know the optimal water level to set, we don t know how to adjust gates so as to get it 15

16 PID Controller The average value computed in task1 is used as setpoint of a PID (Proporzionale, Integrativo, Derivativo) controller e t setpoint t output t u t K e t K e d K e t verage Water level Gate opening degree p i t 0 d d dt 16

17 SWMM simulation software DSRT 2011, September 4-7, Salford, UK 17

18 Customizing SWMM SWMM Real-Time connector Gossip-lgorithm + PID DSRT 2011, September 4-7, Salford, UK 18

19 Experimental results Uncontrolled Controlled 19

20 ny questions? 20