While all machinery and structures vibrate, monitoring excess vibration is key to early identification of asset issues. Vibration monitoring devices use accelerometers to measure changes in amplitude, frequency, and intensity of forces that damage rotating equipment. Studying vibration measurements allows teams to discover imbalance, looseness, misalignment, or bearing wear in equipment prior to failure.
Our use case has particular requirements, so we will focus on the following long term solar powered vibration monitoring PCB. As you can see, it uses 4 tiny solar cells which provide all the energy required by the device. Energy is stores in a Lithyum Ion Capacitor (LIC) which is a very durable energy storage solution. Even if it has not such an energy density as a LiPo battery, it endures x10 charge and discharge cycles.
Seeed Fusion offers one-stop prototyping services for PCB manufacture and PCB assembly, and they take care of the entire fabrication process, from PCB manufacturing and parts sourcing to assembly and testing services, so you can get a quality product.
A transparent enclosure was selected to protect the PCB while keeping solar harvester still operational. Below we can see.
But let´s have a closer look to energy consumption of the board next. We used a Power Profiler Kit II measurement tool from Nordic Devices.
Wio-WM1110 Module🔍The Wio-WM1110 is a fusion positioning module for developing low-power, long-range IoT applications. It's embedded with Semtech LR1110 and Nordic nRF52840, and features Semtech's LoRa technology for long-range wireless communication, GNSS, Wi-Fi, and Bluetooth for location tracking services.
Maintaining current consumption low is critical for our application, as it will be solar powered. Current draw in sleep mode is kept low under 12uA, while there are consumption spikes mainly when LoRa data transmission is performed, reaching up to 48mA instantaneous consumption.
In the next graph, deep sleep current consumption is shown at 11.68uA.
Next, current consumption is measured during LoRa data transmission, reaching up to 48.09mA during a short period of time.
- IIS3DWB accelerometer from ST is a system-in-package featuring a 3-axis digital vibration sensor with low noise over an ultra-wide and flat frequency range. The wide bandwidth, low noise, very stable and repeatable sensitivity, together with the capability of operating over an extended temperature range (up to +105 °C), make the device particularly suitable for vibration monitoring in industrial applications.
Selected sampling frequency for the measurements was 1024Hz.
Now we will see an abnormal acceleration signal and its FFT.
Now we proceed with the AI learning process, we use Nanoedge Studio software for it.
We were able to detect vibration anomalies... Please keep tunned, we are currently working on it. Will complete the post soon with all the details.
Applications 🎯Vibration monitoring has a wide variety of applications in industry, construction, infrastructure maintenance etc. In our case, we are mainly interested in transport infrastructure such as sea conditions for cargo ships, roads (bridges, slopes...), and train railways.
Road transport network monitoring in Castilla y León:
A prototype of CyLoG Open Data based web service can be accessed with the link: www.cylog-data.online (also see http://cylog-data.online/Logistica/)
Some of the used Open Data sources are:
-Electric vehicle charger locations
-Air quality measurement stations data
Sea condition monitoring for cargo ships:
For further academic projects on smart logistic infrastructure, please have a look to the proceedings of "26th IEEE International Conference on Intelligent Transportation Systems ITSC 2023" to be held on 24-28 September in Bilbao.
Ivan Arakistain
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