Data acquisition campaign using BLE started

To address the problem of monitoring the cutting process in the case of open-frame diamond-wire gang saw, Magenta started a new data acquisition campaign based on Texas Instruments’ SensorTag, which is a small battery-powered device integrating a bunch of different sensors and based on Bluetooth low-energy (BLE) tecnology.

Using a few SensorTags, Magenta explored the possibility of evaluating the quality of the cutting process by sampling vibrations and temperature in different points of the diamond-wire gang saw. The task revealed to be a hard one, since the environment in which the devices are supposed to work is hostile, due to the mist of water and stone dust that spreads in the air during the stone cutting. However, engineers were able to acquire some interesting data, shown in the following.

These are a few pictures of the diamond-wire gang saw used for the data acquisition campaign.

The most interesting features from all the collected data are summarized in the plots below.

A machine start-and-stop, without cutting, produced the following pattern in the values acquired by accelerometers:

At the beginning of the whole cutting process, procedures require a machine break-in that lasts for about 20 minutes. The beginning of the break-in phase produced the following pattern:

When the break-in phase is completed, the diamond-wires starts moving down towards the stone. When the wires touched the stone, vibrations grew up and we observed this pattern in the accelerometers output:

At the same time, the thermometers catch an increase in temperature: