Sewio RTLS 2.5: First RTLS in the World to Enable Full Visibility into Narrow Aisles with Unmatched Cost-Effectiveness

Why is 1D tracking with directional antennas a significant evolutionary step in the expanding market of indoor location tracking services? Production halls, warehouses and distribution centers all include corridors and tight aisles that are too complicated and costly to be covered by a grid of omnidirectional antennas providing 2D tracking. However, customer use cases require exact real-time position in the aisles. This is where UWB directional antennas and 1D comes into play, fulfilling customer needs while drastically cutting deployment costs. Suddenly, fewer anchors (antennas) and cabling are needed.

Depending on the facility’s layout, RTLS project costs can be cut by anywhere between 10-50%, resulting in enabling indoor tracking projects for even tighter innovation budgets in the post-COVID era. And in general, shortening the overall payback period of the project.

One of the first Sewio RTLS customers leveraging the combination of 1D and 2D tracking was an unnamed car maker Europe. While covering their production hall solely with 2D tracking would require 187 anchors, the combination of location modes lowered the number of needed anchors to 116 cutting the infrastructure costs including the cabling by 38%.

A) Close-up of the hall: Area covered solely by omni anchors (2D tracking only)

B) Close-up of the hall: Area covered by combination of directional and omni anchors (1D and 2D tracking)

The 1D tracking feature has been brought with the latest Sewio RTLS 2.5 release and enabled by the latest industrial anchors release.

Searching for material, misplaced items or wrong shipments leading to longer lead times and decreased OTIF are a few of the inefficiencies that can be easily eliminated by tag-less asset tracking. Why “tag-less”?

Instead of equipping each asset with a tag, resulting in thousands of tags to be tracked, the tag is featured only at the forklift that is moving the asset. The sensors for the fork load registers anytime the forklift (un)loads the asset and the QR code camera records the particular asset code. At the same time, the UWB tag at the forklift adds the exact position.

Each of the forklifts is utilized differently – one being in operation for 92% of time, another only for 76%. Which are the best performing ones and which are the underperforming? And then what, where and when causes the worst ones not to perform?

It is not practical to track and record every minute the movement of each of the forklifts manually. RTLS brings in reliable data about each forklift, including the run/stop time, distance traveled and OEE, resulting in a single source of disprovable truth about each forklift. Having the spaghetti diagrams, heatmaps and detailed historical tracking data allows users to identify and solve what is blocking their forklifts to reach higher OEE.

Accidents between people and the forklift or two forklifts especially tend to happen at the entrances and exits of tight aisles where the view is limited. That is also the reason why many safety solutions, including the peer-to-peer systems, fail to operate and prevent injuries.

Only an infrastructure based on RTLS with precise 1D tracking within the aisle can provide real-time reliable data to alert the necessary people and prevent any injuries.

Read more about the different indoor location modes that can be leveraged within Sewio RTLS.

The reliability and scalability of a Time Difference of Arrival (TDoA) based location system is highly affected by the synchronization model being used. Each anchor in the RTLS can receive the positioning signal or synchronization signal at the same time. It is, therefore, crucial how the time slots are reordered, shrined and expanded in order to achieve the best performance. Slot alignment is managed by TDMA (Time-Division Multiple Access), which uses either a UDP or TCP synchronization protocol.

UDP Synchronization

TCP Synchronization

UDP AD Synchronization

While the UDP protocol is very straightforward and reliable as it sends a single broadcast message from a RTLS Server, it’s also limited by the fact that all anchors must be within the same network as the server. The TCP protocol ensures the anchors’ synchronization one by one via a continuous TCP connection, which solves the biggest obstacle of UDP – the server can be on a different network (and at a greater distance) than the anchors. This advantage comes at a cost, the TCP synchronization startup time is longer as the whole TCP tree must be built, and anytime one branch is temporarily broken, the tree must self-heal, decreasing its reliability.

The new UDP AD (anchor-driven) synchronization, which debuts in Sewio RTLS 2.5 as a beta version, takes the best of both worlds of synchronization. UDP AD synchronization is sent by anchors instead of servers, just as in a TCP sync, but via the Ethernet cable, just as with UDP. Unlike UDP, it uses the full channel capacity and the RTLS Server can be on a different network to the anchors. And unlike TCP, the startup time is immediate and the reliability is the highest possible as the sync cannot be blocked.

Sewio RTLS 2.5 also includes major improvements to the current TCP model, which will still be used for Wi-Fi or hybrid (Wi-Fi and Ethernet) installations. In addition to this, the improvements include quicker self-healing tree initialization and more robust time domain splitting.

For more information, please see TDMA Synchronization in the documentation.

Besides the two-dimensional indoor tracking, Sewio RTLS also allows height (Z-axis) tracking. The challenge of barometer-based Z-axis tracking is that the barometer isn’t stable over a longer time, thus recalibration needs to be performed on a regular basis.

While the tag calibration adds to the maintenance cost, the latest Sewio RTLS streamlines and simplifies the process by introducing an API for re-calibration. This brings automatic calibration of tags based on the time and/or the zone. For example, the system can automatically calibrate all tags that are at 23:45 in a given zone (=usually a place/time where tags are being stored).

This addition supports people-tracking use cases that require floor-level determination for complicated multilevel mezzanine deployments in industrial environments where unwanted signal penetration among multiple floors occurs.

Furthermore, direct Z-axis data from a barometer can be utilized in use cases requiring temporary high-accuracy 3D tracking for training units (military/police/firefighters) or different people-tracking applications in the entertainment industry.

The installation of software often needs to download additional packages online – a practice that is convenient for end users at their home, but not in strict and bandwidth limited networks in industry. That’s why RTLS Studio bundles (Docker, Vbox, Native installation) now works as standalone application without the need of the internet connection as all required packages are already part of the install bundle. You can install RTLS Studio 2.5 or higher on Ubuntu Server 18.04 LTS (64-bit) or deploy it on the Docker in a server room without the internet connection.

The list of new features and UX improvements brought with 2.5 doesn’t end here. For a full list, please read the RTLS Studio documentation.

You could also take the Sewio RTLS 2.5 Product tour at your own pace or download the recording of the webinar “First Truly Affordable RTLS for Industry: Sewio RTLS 2.5“ that covers the 2.5 release feature set.

Sewio partners can download the latest version of RTLS Studio from the Sewio portal and it is also possible to evaluate the new features via a hosted live demo version on the Sewio website.