An Introduction to Wireless Monitoring Systems By Daniel Scott Technical Development Manager ITM-Soil Group [email_address]

Introduction to the principles of Monitoring, Field Measurements and the Site Environment Why go Wireless? Wireless Mesh Networks Tutorial Soil Instruments Wireless Network Module Intelligent Monitoring System Example

Introduction to the principles of Monitoring, Field Measurements and the Site Environment

Why go Wireless?

Wireless Mesh Networks Tutorial

Soil Instruments Wireless Network Module

Intelligent Monitoring System Example

Goal of the Monitoring System The goal of a monitoring system is to detect changes in physical parameters that are of decision-making importance

The goal of a monitoring system is to detect changes in physical parameters that are of decision-making importance

Goal of the Monitoring System The system is a functional success if the information generated from it is: Consistent, accurate and valid Represented in some form of standardised unit Of engineering significance The system is financially sustainable if the Information obtained from it is of more value than the cost of the systems implementation: Decrease the cost of implementation Increase the value of the data

The system is a functional success if the

information generated from it is:

Consistent, accurate and valid

Represented in some form of standardised unit

Of engineering significance

The system is financially sustainable if the

Information obtained from it is of more value

than the cost of the systems implementation:

Decrease the cost of implementation

Increase the value of the data

Goal of a Monitoring System 0001100111001 Operators, Engineers, Consulting Engineers, Risk Ans, Neural Networks Spread Sheet, Software, Web Based Manual, CAN, RS485/Short Haul Modems, TCP/IP Binary, Hex, ASCII Voltage, Current, Frequency, Count, Digital mm, Hz , N, Pa, V, A, Ω , °C Observer Presentation Transport Data Signal Sensor Physical Phenomenon

Why Monitor? Risk analysis Design verification Development of new constitutive laws Project management Process control and optimisation Asset and infrastructure management Post-construction problem diagnosis

Risk analysis

Design verification

Development of new constitutive laws

Project management

Process control and optimisation

Asset and infrastructure management

Post-construction problem diagnosis

Alternatives Assumptions Ignorance Over design Adoption of greater risk

Assumptions

Ignorance

Over design

Adoption of greater risk

The Challenge Providing detailed information about the real world that is of importance to engineers and practitioners Lab-Level metrology within the field environment

Providing detailed information about the real world that is of importance to engineers and practitioners

Lab-Level metrology within the field environment

Extreme environments

Extreme environments

Extreme environments

Why Wireless?

… manpower Cabling sensors… Finding: Committed Good Skilled people Intricate Systems

Finding:

Committed

Good

Skilled people

… disruptive environments Cabling sensors…

… machinery Cabling sensors…

… Problems with Safety … cable susceptible to damage Cabling sensors…

… Inter-Cable signal Interference Cabling sensors… … Cable Management … Complex Wiring Requirements … Difficult Access

… high cost of installation Cabling sensors…

Wireless monitoring using Mesh Networks

Wireless monitoring using

Mesh Networks

Network Sensor Module (Node)

Network Sensor Module (Node) Sensors and nodes are put in place

Wireless Data Link The network collects, stores and shares sensor data

Network Gateway Wired Data Link Wireless Data Link A node is selected as the gateway Wired or wireless loggers are connected to the gateway

A data path may become blocked The network will reroute the data via a different node Network Gateway Wired Data Link Wireless Data Link

Network Gateway Rerouted Wireless Data Link Data are again rerouted when the obstruction is cleared This is a “Self Healing Network”

Network Gateway Wired Data Link Wireless Data Link Access to the network can be made from any node

Network Gateway If connection to the logger is lost… Data are stored within the network until connection with the logger is restored

Network Gateway When connection is restored, the logger can collect data from network

New wireless sensor nodes are installed in a nearby location The nodes are out of range of the working network … and a brick wall is in the way Placing two nodes as repeaters, the new sensors are able to connect to the existing network

Placing two nodes as repeaters, the new sensors are able to connect to the existing network

Wireless Network Module

Wireless Network Module IP68 Box Interface for any sensor 9V battery 75x119x58mm 395g RS232 serial connection External power control

IP68 Box

Interface for any sensor

9V battery

75x119x58mm

395g

RS232 serial connection

External power control

Sensor Reading Multiplexed Voltage Output Electrolevel Solid State Vibrating Wire Thermistor 4-20mA Pulse Counter Digital Piezometers Pressure Cells Inclinometers Extensometers Load Cells Weather Stations Settlement Cells Thermometers Etc

Multiplexed

Voltage Output

Electrolevel

Solid State

Vibrating Wire

Thermistor

4-20mA

Pulse Counter

Digital

Piezometers

Pressure Cells

Inclinometers

Extensometers

Load Cells

Weather Stations

Settlement Cells

Thermometers

Etc

Datalogging 1,000,000+ Readings per Module Upgradeable Memory User Configurable Reading Intervals Alarm Functions Threshold-Based Reading Intervals Request Specific Date/Time Information Instantaneous Readings Cal factors Engineering Notes

1,000,000+ Readings per Module

Upgradeable Memory

User Configurable Reading Intervals

Alarm Functions

Threshold-Based Reading Intervals

Request Specific Date/Time Information

Instantaneous Readings

Cal factors

Engineering Notes

Telemetry PC/Laptops Handheld Computers Existing Dataloggers Short-Haul Modems GSM/GPRS modem Satellite modem IP Addressable (Access over the Internet) Access every Sensor from one Gateway

PC/Laptops

Handheld Computers

Existing Dataloggers

Short-Haul Modems

GSM/GPRS modem

Satellite modem

IP Addressable (Access over the Internet)

Access every Sensor from one Gateway

Battery Life Battery Type Type of Sensor Frequency of Readings Frequency of Radio Transmission Processing Requirements Temperature External Energy Sources This is a Dynamic System, Battery Life depends on:

Battery Type

Type of Sensor

Frequency of Readings

Frequency of Radio Transmission

Processing Requirements

Temperature

External Energy Sources

Sensor Performance Absolute: 24bit ADC ± 0.05mV 0-2.5V dc Resistance <1% in 100-50k Ohms Range (~0.15ºC) Vibrating Wire 0.5Hz Accuracy @ 400-5000 Hz Engineering [100mm Linear Potentiometer] Stability 0.003mm 0.1mm Accuracy 0.01mm Accuracy w/ Calibration

Absolute:

24bit ADC

± 0.05mV 0-2.5V dc

Resistance <1% in 100-50k Ohms Range (~0.15ºC)

Vibrating Wire 0.5Hz Accuracy @ 400-5000 Hz

Engineering [100mm Linear Potentiometer]

Stability 0.003mm

0.1mm Accuracy

0.01mm Accuracy w/ Calibration

2.4 GHz Radio Pros: Operates Globally, Licence Free High Data throughput (<250kb/s) Short Wake times High complexity of Network organisation Optimised at a Suitable Range 1-100mW output allowed (30m-1Km+) Cons: Higher attenuation than lower frequencies Greater power drop off

Pros:

Operates Globally, Licence Free

High Data throughput (<250kb/s)

Short Wake times

High complexity of Network organisation

Optimised at a Suitable Range

1-100mW output allowed (30m-1Km+)

Cons:

Higher attenuation than lower frequencies

Greater power drop off

Wireless monitoring on Dams using Mesh Networks

Wireless monitoring on Dams using Mesh Networks

Network Sensor Module (Node)

Wireless Data Link Network Sensor Module (Node)

Network Sensor Module (Node) Wireless Data Link

Network Sensor Module (Node) Wireless Data Link

Network Sensor Module (Node) Wireless Data Link

Network Sensor Module (Node) Wireless Data Link

Network Sensor Module (Node) Wireless Data Link

Network Gateway Wireless Data Link

Network Gateway Wireless Data Link

Speed of Installation Flexibility Scalability Access to Data Inherent Lightening Protection Reduction in need for Multiplexers Terminal Boxes Dataloggers

Speed of Installation

Flexibility

Scalability

Access to Data

Inherent Lightening Protection

Reduction in need for

Multiplexers

Terminal Boxes

Dataloggers

Intelligent Monitoring Automatic optimisation of read/report cycles Event monitoring Power saving Automatic notification of maintenance Requirements Flagging of extraordinary readings for Engineering analysis Collaboration between sensors

Automatic optimisation of read/report cycles

Event monitoring

Power saving

Automatic notification of maintenance Requirements

Flagging of extraordinary readings for Engineering analysis

Collaboration between sensors

Intelligent Wireless Sensors A Case Study

Flood Monitoring

Flood Monitoring

SOLID STATE PRESSURE TRANSDUCER

TRANSDUCER IS INSTALLED INTO SLOTTED HDPE TUBE…

… AND INSTALLED BELOW THE WATER

GPRS MODEM LOGGER IS USED TO STORE AND COMMUNICATE DATA…

… AND IS CONNECTED TO THE PRESSURE TRANSDUCER

AT NORMAL WATER LEVELS, DATA TRANSMSSIONS NEED ONLY TO BE SENT ONCE A DAY Data sent every day

WHEN WATER LEVEL RISES TO PRECONDITIONED LEVELS, THE SENSOR DATA CAN BE TRANSMITTED MORE OFTEN Data sent every 10 minutes

IF FLOOD CONDITIONS ARE DETECTED, ALARMS CAN BE SENT AND SENSOR DATA TRANSMITTED MORE FREQUENTLY Alarms sent and data transmitted every 2 minutes

Future Developments Over Air Programming Onboard Math / FFT’s Integrated Telemetry Energy Harvesting Security Encryption Continual Advancement of Sensor Functions Development of further system intelligence

Over Air Programming

Onboard Math / FFT’s

Integrated Telemetry

Energy Harvesting

Security Encryption

Continual Advancement of Sensor Functions

Development of further system intelligence

The Future What do you want to do?