Recent studies seek to present solutions for one of the great managerial problems faced by companies, which consists of the need to have an accurate management and localization of their assets, especially in cases where there is a large amount of equipment and machinery.

These companies need to have a rigorous control of these assets, identifying their location when necessary, generating periodic reports for presentation in audits, and solving inventory problems by writing off the assets.

This case study presents a possible solution to be used by companies to manage high value-added assets, so that they are not lost in the manufacturing environment, generating setbacks and additional resources for the company in the search and location of the item. For such a solution, an internal proof of concept was created to help in this management and provide a localization of the assets.

The proof of concept was conducted using some application and service boards developed by the internal research and development team of Zilia Brazil.

Below, the description of the items used:

• Zilia SWAP-LRSVCB01 Module (Figure 1), also known as Service Call Button (SVCB);
• LoRa^® Gateway for structuring a private network to enable the connection of SVCBs to the LoRa^® network;
• Platform for the development of a dashboard to locate and manage IoT devices connected to the company’s assets;
• Operator LoRa^® Network, for the transmission of the location information.

To enable the evaluation of the solution, some equipment received in its structure a sample of the SVCB and the use of this module allowed the identification of the exact position of the large assets.

It is important to note that it was not possible to triangulate the location of the assets because only one LoRa^® gateway was used. But this process is totally pertinent to the technology currently available, all that is required is some changes in the method adopted in the measurement of the transmitted signal level and the development of a software algorithm that allows for greater precision in the location of assets, especially for those of smaller size.

The technical principle used to determine the estimated position of the asset within a given area was through the signal strength received by the gateway in decibels (dB), making it possible to determine a location radius for the monitored item.

To determine the range of variability of the ambient power, a survey of measurements was performed in the area to estimate the signal strength at various points in the plant. In this way it was possible to define a range of measurements for each point in the coverage area.

 The radio power of the SVCB module was adjusted so that it would work with good performance in a specific coverage area and have a fast signal attenuation when moving away from the management gateway.

With the registration of the SVCB modules in the LoRa^® operator, it was possible to start the process of data acquisition through the provided services. Next, a dashboard was developed to allow the adjustment of some SVCB configurations ensuring its monitoring. Figure 2 presents the structure of the proposed system to support the asset monitoring process.

Currently, there are several platforms dedicated to developing dashboards for IoT devices. Zilia decided to do the development to support this case study. The SVCB module through the Gateway and a network operator are compatible with most of these platforms, which can speed up the process, giving companies more flexibility in developing their solutions.

Figure 3 illustrates two representations, one by the location point of the fixed asset, the other by the rectangle, which shows us the possible current location area of the tag in the floor plan.

Defining it we have:

Green rectangle – signals that the asset is within the performance area, the signal strength in dB cannot be less than -100dB.

Green dot – signals that the SVCB device is fully active and has not been triggered by the accelerometer or by pressing the signal button.

Alarms – can be triggered in the following situations:

• In case of button press or machine movement, the green dot turns to yellow;
• When there is a shift of the asset outside the green area boundary;
• The Reception Signal Strength Indication (RSSI) will decrease to a value below -100dB (e.g. -112dB) resulting in an area alarm. Thus, the green rectangle will be replaced by a yellow rectangle with a larger area;
• If the signal is lower than -115dB, the yellow rectangle will be replaced by a red rectangle, and will remain so even when the signal disappears, signaling that the asset has left the system coverage area.

Based on the results achieved with this case study, it was possible to identify relevant benefits that were raised with the proof of concept.

Below is a list of the most relevant benefits:

1. Low cost of the SVCB device, depending on the type of asset being monitored;
2. Improvement of the company’s asset management process, enabling its location whenever necessary;
3. Greater agility in locating certain items whenever necessary;
4. Depending on the size of the asset, there are other Zilia solutions that can be used for asset monitoring, with totally feasible implementation;
5. The SVCB device has a low maintenance cost, limited to battery replacement, which lasts approximately one year, depending on the frequency of use of the device;
6. The low costs with the contracting of the operator, considering that one contract has coverage for all the assets being monitored;
7. Short development time for a solution, depending on the platform chosen and the developer’s experience;
8. Depending on the platform selected, it is possible to generate a list of all the assets through the click of a button, and remotely.

By Rodrigo Queiroz, Fabio Bauman and Cleber Figueira