Technology

SYSTEM COMPONENTS

EASY TO INSTALL SENSOR

  • Integrated 32 bit microcontroller for on-board signal conditioning and data processing
  • MEMS accelerometers and tiltmeters, stress and distance measurements
  • Temperature compensated
  • Powerline communication spans hundreds of meters and simplifies installation
  • CAN bus for accelerometer and audio data with repeater functionality
  • LoRaWAN radio option with range of several kilometers
  • Dedicated mobile application for simple installation and configuration

CONCENTRATOR

  • Storage of sensor data and transmission to the cloud
  • On-board data processing with Python plugins
  • Wi-Fi configuration with embedded dashboard
  • Remote maintenance

ANALYTICS AND CROSS-CHECK AMONG DIFFERENT PHYSICAL MEASUREMENTS PROVIDE A ROBUST SELF VERIFICATION SYSTEM

CLOUD INFRASTRUCTURE

  • IBM Cloud multi-tenant environment
  • Real-time alert generation and batch processing
  • Data storage and replication
  • REST API for integration

FINAL REPORTING

  • Disaster prevention and essential maintenance
  • Safety/Reliability thresholds

AN IMPORTANT SET OF EXPERIMENTAL RESULTS

  • 1.2 Km heavily damaged bridge. Sacertis detected the traffic crossing the bridge at any given time and the relevant dynamic rotations of the beams
  • The main vibration mode measured on a wind tower perfectly matches the predictions of the Mathematical Model
  • Road tunnel during excavation phase: data have been collected before and after the fall of the last diaphragm. Below 1 mm displacements have been detected
Performing advanced linear and 
non-linear analysis
Assessing predictive and post-event risk
Providing data for reliable and continuously updated models

Life cycle Management

  • PHASE 1 Assessment of structural performance and reliability
  • PHASE 2 Risk Assessment (Evaluation of economic consequences) in the life-Cycle
  • PHASE 3 Optimization of risk-informed decision making process and maintenance strategy
  • PHASE 4 Updating of structural health monitoring (SHM)

DETAILED PRODUCTS

The SAFE CERTIFIED STRUCTURE product family includes sensors, concentrators and a cloud platform. These elements work together to assess the structural health of civil structures and their evolution over time. The goal is achieved by measuring key structural parameters (vibrations, tilting, pressure and others) and applying suitable algorithms to detect significant changes.

Concentrator

The Sacertis concentrator stores, processes and forwards sensor data to the cloud through an LTE connection.
Based on a powerful ARM/Linux platform, it filters redundant information, reducing the amount of data transferred to the cloud, thanks to remotely injectable data processing plugins written in the Python programming language.
The concentrator creates a protected Wi-Fi network that is used during installation and maintenance to perform functional tests on the sensor system.
In typical installations, several hundreds of sensors can be connected to the concentrator by choosing among powerline, CAN bus and LoRaWan(TM) radio connectivity options.
On the concentrator data is stored in a SSD, which is used as a local cache to avoid data loss in case of intermittent Internet connectivity; database dumps are periodically synchronized with the cloud.
The concentrator forwards sensor data and several statistics to the cloud platform (along with measured data) using the MQTT protocol on a TLS secure socket towards the IBM Cloud.
It comes in a DIN rail mount box suitable for indoor and outdoor mounting.

Tilt Sensor Device

Based on a biaxial MEMS accelerometer, a tilt sensor device is available to measure angles with a resolution of up to 1.4 x 10-3 degrees (when mounted horizontally with a full-scale of +/-0.5g) over a wide temperature range. The sensor is powered at 230VAC and sends measurements back to the concentrator using narrow-band powerline communication. Hundreds of Tilt Sensor Devices can be chained together and each device can be configured as a powerline repeater to further extend range. The device can have other sensor nodes connected such as stress sensors, crack meters and temperature probes.

Cloud infrastructure

Data streams received by multiple installations are analyzed and stored in the IBM Cloud multi-tenant environment that uses state-of-the-art technologies to achieve scalability and high availability. Sacertis authored algorithms are applied to sensor data to extract relevant Key Performance Indicators for every structure type and follow their evolution over time. Diagnostic information can be made available through secure REST API, for ease integration into customers' IT infrastructures.

Triaxial Accelerometer Sensor Device

The three axis MEMS accelerometer uses CAN bus connectivity to send accelerometer data to the Sacertis concentrator.
The sensor performs signal conditioning functions, thanks to its powerful STM32 microcontroller. Accelerometer signal sampling frequency can be adjusted between 50, 100, 200 and 4000Hz, depending on the application. Each accelerometer sensor is time synchronized with a common clock running in the concentrator. After sampling and digital filtering, accelerometer data can be analysed for anomaly detection in time or frequency domain.
Signal statistics and anomalies are transmitted over CAN bus along with actual data samples.
Sensor firmware can be remotely upgraded.
When cabling is not viable, accelerometers can use LoRaWAN radio and send threshold passing events.
Accelerometers come in different form factors, either 230VAC powered (sensor devices) or 24VDC powered (sensor nodes).
Accelerometer sensor devices have two distinct CAN bus connections that can be bridged to extend range or implement different topologies.
The number of accelerometers that can be chained together on the same bus depends on the total length, the sampling frequency and the network topology but can easily reach tenths. Sensor devices can have other sensor nodes connected (stress sensors, tilt meters, crack meters and external temperature probes).