LoRaWAN accelerometer for structural health monitoring

../../_images/preview5.png ../../_images/enclosure-with-antenna.jpg ../../_images/incl-g104mf-bridge.jpg

1.0.0: Field test ongoing (3 prototypes) 1.1.0: Design ready

Introduction

incl-g104mf is a commercial product for structural health monitoring and measurement of self-resonant frequencies of buildings and steel bridges, more specifically. It is a battery powered device in an aluminium waterproof enclosure with dimensions of about 60x50x40 mm attached to the building using strong neodymium magnets.

Acceleration is being measured with a sample rate of about 100 Hz with a range of +- 2.5g in all three axes. The measured acceleration and temperature data is processed using a customer defined algorhitm and transferred over the air to the server infrastructure.

A low power ARM Cortex-M4 microcontroller running at 80 MHz with 160 KB of SRAM is used to provide enough resources to run the required data processing even in real-time while being fed only from a single LiSOCl2 battery.

The 1.1.0 hardware version extends the functionality with more accelerometer sensors for different purposes (high performance low noise, low power), gyroscope, USB connectivity for configuration and measurement data download, and a micro-SD card slot for storing long series of raw measurement data.

The device is capable of running the plumCore DAQ/IoT framework available on GitHub with an open source BSD license.

Hardware design files for this device are not publicly available. If you want to buy the device, contact me at qyx@krtko.org and request a quote.

Specification

Environmental [SK]

Rozsah prevádzky: - rozsah teplôt -40°C do +85°C, vrátane zdroja energie - obal vodotesný do IP67

Radio [SK]

Bezdrôtový prenos dát rádiom:

  • LoRaWAN certifikovaný modem, vyhovuje ETSI EN 300 220

  • Rozsah pracovných frekvencií 863.000 MHz do 870.000 MHz a 433.050 MHz do 434.790 MHz

  • Výstupný výkon 10 dBm (v pásme 433 MHz), 14 dBm (v pásme 868 MHz)

  • Citlivost vstupu -146 dBm (v závislosti od nastavenia prijímača)

  • Anténa 2JW0815-868-C20N

  • Kryptografický koprocesor & secure storage pre zabezpecenie komunikácie (voliteľne)

Power [SK]

Napájanie:

  • 1 kus lítiová batéria (LiSOCl2 3.6 V) veľkosti 14500 (AA), rozsah 2.3 V - 5 V

  • Doba prevádzky cca 1 rok, závisí od spôsobu použitia zariadenia

Sensors [SK]

Merané veličiny:

  • zrýchlenie v troch osiach v rozsahu ±2.5g s rozlíšením 0.076 mg a vzorkovacou frekvenciou max. 1100 Hz

  • náklon v troch osiach s rozlíšením min. 0.005°

  • teplota v celom prevádzkovom rozsahu s rozlíšením typ. 0.01°C, prenosť ±0.1°C (+35.8°C do 41°C), ±0.13°C (20.0°C do 70.0°C), ±0.25°C (-40°C do +85°C)

  • svetlo vo viditelnom spektre pre účel detekcie manipulácie so zariadením

Obsluha:

  • USB konzola pre nastavenie, logovanie a výstup dát

  • LED indikácia stavu