1.How does KIO RTLS work?
KIO RTLS consists of tags, anchors and server software. The evaluation kit comes with 4 anchors ( types A, B, C and D) and 1 tag. In reality, set ups could include tens, even hundreds of tags and anchors.
Every tracked object needs to have a tag, whether it’s a vehicle or a person. The four types of KIO anchors work a bit like beacons. In order to determine the tag’s position, the system measures the distance between each tag and the four anchors using the time-of-flight method. This happens multiple times per second and gives the real time location of the tracked object.
The KIO RTLS is based on ultra wideband (UWB) radio technology. The ultra wideband radio was originally used by the military and is quite immune to obstacles. Thereby, KIO gives reliable results about each tag’s location even if there is no direct line of sight between the tag and the anchors. The most challenging materials to penetrate for the UWB radio are liquids and metal objects.
2. How to set it up?
When setting up the KIO RTLS for the first time, there are a few things to consider. The anchors are usually installed on upper corners of the walls or poles to ensure a wide line-of-sight. They require a power connection and each anchor works reliably in a range of 40 metres in direct line of sight. Although the shape and type of the area can influence the positioning accuracy, the rule of thumb says that one anchor can cover around 100 to 150 m2.
The KIO RTLS is highly scalable with the ability to cover large areas with anchors and track hundreds of objects. It’s easy to extend the positioning area, it only requires adding another set of ABCD anchors. It’s important to make sure the new anchors are set up so that the tag can always communicate with one A, one B, one C and one D anchor. This ensures that the algorithm is always able to determine the most accurate position for the tag. It’s also important to note that the more tags there are to position for a set of anchors, the less frequently they can be positioned.
3. How to collect the positioning data?
As mentioned before, to determine the exact position of the tag, the system measures the distance between each tag and four different anchors using time-of-flight method. The distance measurements can be collected from both the tag and the anchors. Whether to use a tag or an anchor for data collection depends on your use case. For example, when there are many tracked objects, it’s easier to collect data from the anchors. When the tracking area is larger and needs more than one set of anchors, data needs to be collected from every fourth anchor.
The distance measurements need to reach a computer where the KIO API performs the multilateration calculations. The KIO algorithm turns the measurement data from different anchors into precise tag coordinates. The output data is the form of XYZ coordinates for each of the tag in each point in the tracking area. The KIO API can also feed this data into other information systems for further processing.
Hopefully this has helped you better analyse your own technology needs. We at Eliko are working with clients with very different use cases. Don’t hesitate to send me an e-mail if you have further questions about the setup.