A CPS-Enabled Architecture for Sewer Mining Systems

Lazaros Karagiannidis, Michalis Vrettopoulos, Angelos AmditisInstitute of Communication and Computer Systems

National Technical University of Athens

Effie Makri, Nikolaos GkonosTELINT RTD Consultancy Services Ltd.

2nd International Workshop onCyber-Physical Systems for Water Networks

CPS Week 2016, Vienna, Austria, 11thApril 2016

The Challenge

Issue

One of the key challenges in the development of CPSs is interoperability.

Solution

Utilizing standards, such as the Open Geospatial Consortium’s (OGC) Sensor Web Enablement (SWE) standards, will, amongst others, ensure the development of CPSs which consist of heterogeneous sensing elements to be interoperable and seamless in their potential interaction.

DESSIN Solution

A software/hardware platform was developed for the monitoring and control of small packaged plants for urban sewer-mining.

Integrated devices:

• data collection tools

• sensing elements providing monitoring

• configuration tools

Components

• Sensors/probes for measuring various water characteristics

• An industrial data logger/sensor controller

• Several pumps, valves and flow meters

• An industrial Programmable Logic Controller (PLC) with a corresponding HMI.

Sewer Mining CPS Enabled Architecture

Components of Sewer-Mining System

The sewer-mining system consists of a container divided into several tanks:

• primary tank

• de-nitrification tank

• nitrification tank

• membrane tank

• excess sludge tank

Components of Sewer-Mining System

The Ultra-filtration module consist of:

• an air distribution system

• aeration elements

• membranes

• pumps

An activation space is used for biological treatment (denitro-nitro) of wastewater and ultra-filtration through membranes.

Sewer Mining CPS Enabled Architecture

Water Characteristics Measured

The water characteristics measured indicate the quality of water at the different stages of the treatment process through the various compartments and tanks. E.g.

• Mixed Liquor Suspended Solids (MLSS)

• Nitrate,

• Chloride,

• Turbidity

• Temperature

Water Quality Probes / Sensors

Name Location(s)Unit of

MeasurementMLSS Membrane Tank mg/LTurbitity Permeate Tank – Inlet to RO NTUPH RO Effluent, Membrane Tank pH

TemperatureRO Effluent, Aeration Tank, Permeate Tank –

Inlet to RO, Anoxic Tank, Membrane Tank°C

DissolvedOxygen

Aeration Tank mg/L

Conductivity RO Effluent, Permeate Tank – Inlet to RO, Inlet μS/cmAmmonium Aeration Tank mg/LNitrate Aeration Tank, Anoxic Tank mg/LChloride Aeration Tank, Anoxic Tank mg/LPotassium Aeration Tank mg/L

Sewer Mining CPS Enabled Architecture

The Microcontroller

• The microcontroller is responsible for collecting data from the water quality sensors through

• the industrial data logger/sensor controller

• the mechanical parts of the sewer-mining unit through the PLC.

• The microcontroller

• implements a protocol adaptation layer, hiding the complexity of the communication protocols used by the devices

• is equipped with suitable communication interfaces to communicate with the web platform

The ICT Infrastructure • The ICT infrastructure consists of the following components:

• A Raspberry Pi single board computer that acts as the microcontroller with a USB Wi-Fi adapter in order to enable connectivity to the local WLAN infrastructure.

• An RS485 to USB adapter in order to enable connectivity to the data logger/sensor controller through Modbus Protocol.

• A Wi-Fi Access Point and modem router that provides internet connectivity.

• A Server that hosts the web platform and processing functionalities.

• An industrial sensor controller/data logger with Modbus communication interface (Hach’s SC1000).

• An industrial PLC (Unitronics V1210)

ICT Infrastructure Diagram

Standards

Used for:

• the sensor data representation layer

• access

• data exchange

OGC SWE suite

• Sensor Model Language (SensorML)

• Observations & Measurements (O&M)

• Sensor Observation Service (SOS)

• Sensor Event Service (SES)

Data Model

SensorML

• IdentifierList => id, long name, short name.

• ParametersList => location name, minimum threshold, maximum thresholds

O&M

• Procedure => id of the sensor.

• TimePosition => timestamp of the observation.

• Result => the unit and value of measurement.

Software Platform Architeture

SOS/SES Client Architecture

User Control Dashboard Workflow

Sensors Measurements

Real-time Alerting Feature

Sensors Configuration

Platform Settings

Conclusions

• The CPS-enabled platform described provides active monitoring and control of wastewater for urban reuse, based on a SWE-enabled SOA approach.

• The wastewater management and alert system provides monitoring and control functions of the sewer-mining system, including human-interactive features, integration with legacy systems and low cost embedded devices.

• Main effort was to create abstraction of observations, providing interoperability among sensor data representation, data storage and data exchange and enable transformation of monitored data into meaningful and actionable knowledge.

Thank you!