Technical Training L2

The primary goal of this training is to get some practical skills via hands-on experience of using the RTLS TDoA kit.

Our targets

  • Be able to deploy and setup the small RTLS deployment
  • Have an hands-on experience with incorrect anchor placement and their troubleshooting
  • Understand Tag settings and reconfiguration
  • Understand Zone feature and API

Prerequisities

  • Sewio TDoA RTLS Kit (Ethernet or Wi-Fi)
  • Installation of the RTLS Studio 2.0.1 or higher (Virtual machine or native machine installation)
  • Suitable venue to deploy the RTLS system demo - room/area with dimensions of at least 5x5 m
  • Distance measurement tool (ideal laser measurement tool)
  • Plan of the area (at least drawn rectangle with right aspect ratio)


L2 Training Procedure


1. Follow the Install Guide

Follow the Install Guide for the Kit to section "RTLS Studio 2.x". Install guide will guide you trough the system basics and virtual box installation. Please focus primarily on section "Anchors and Tags Deployment Rules", since this section describe rules for achieving sub-meter location accuracy. Not following the rules can have negative impact on the precision of the localization system. 


2. Anchor deployment

TASK TIME: 30 MIN

According to the rules for anchors and tags deployment, try to deploy and install anchors in the room. 

 Hint

Make a picture of each Anchor and the overall area with installed Anchors

Pictures from a real installation can help to identify the Issue with the Anchor. Also, remote communication with Sewio support or with customers will be easier. In bigger projects it is good to have such documentation for each Anchor. Make sure that the orientation and placement of the Anchor is clear from the picture together with any surrounding obstacles.


3. Finish the Install Guide

TASK TIME: 60 MIN

Please follow the rest of the sections in the Install Guide document. Section RTLS Manager will guide you trough the steps on how to check if all the Anchors are visible in the system. It will also show you how to initialize the Anchors and how the synchronization stability between Master Anchor and rest of the Anchors looks like. The RTLS Manager also shows if the activated Tags are visible in the system. Section Sensmap Visualization will guide you on how to set up a background (floor-plan) for the localization. At the end of the guide, it is possible to adjust Anchor positions according to real measurements, or according to measurements between the Anchors themselves (Auto-deployment).


4. Measure the positions of the Anchors

TASK TIME: 30 MIN

Measure the real Anchor positions with a laser measurement tool and set the precise position of Anchors. This step is very important for each project to achieve precise positioning. Only with precise Anchor positions high positioning accuracy of the Tags can be achieved. The Anchor auto-deployment feature is currently in beta stage. This feature can be used during a quick deployment of the RTLS kit.


5. Walking with the Tag

This section is an evaluation test. Walk inside the location area with the Tag with enabled "Nodes Tracking Statistics" at least one minute and try to evaluate if the number of calculated positions corresponds to set RR (Refresh Rate). During this test it is important to notice if the Tag behaves as expected and If the tracked trajectory of movement corresponds to real trajectory. It is also important to check if the precision level is as expected and the density of the positions corresponds to the selected RR. In some use-cases the Tag configuration is set incorrectly and has a negative effect on the performance (Tag is sleeping when it shouldn't be, refresh rate is too low to track an object in high speed etc.). 

If the performance is not as expected, please check the following points:

  • all rules are followed,
  • positions of the Anchors are correctly set in Sensmap,
  • in case of the WiFi kit - check the strength of the WiFi signal (it should be around -60 dBm).


 Hint

Make sure that there is a clear line-of-sight between the Anchors and Tags. If necessary, place the Tag above your head.

We recommend using a Tag that has a disabled sleep mode during the tests to avoid a situation where the Tag is moved, but positions get lost because it has not been woken up from sleep.


6. RTLS Studio Backup

Backup is used to save the current settings of the RTLS Studio. Further information about both Back-up and Restore can be found here. This point is very important for each installation. Every time when the positions of Anchor are changed or some settings of the RTLS Server are altered the performance of localization system can be affected by such changes. For that reason if the system works as expected and you want to try different settings it is highly recommended to do a Backup. Keep in mind that every time when you restore the system from a backup, you lose the historical data including positions between the date of the backup and the date of the restore.

Configuration of the Anchors and Tags is not part of the backup.  


7. Experimenting with the Anchors

This exercise should help you understand what happens when most typical mistakes occur during the Anchor deployment.

TASK TIME: 60 MIN

  1. Switch positions of two Anchors 

    Sometimes it can happen that if you have similar MAC addresses of the Anchors, you may physically switch two Anchors by a mistake. It can also happen during the process of setting up the Anchors coordinates in Sensmap that two Anchors have switched positions by an accident.



    light-on (on) This mistake effects two Anchors, which is leads to a significant error in a setup with five Anchors in total. The positioning error will be so high, that the position might not be calculated at all in the whole area, or the calculated position will have a very little correlation to the real position of the Tag.

  2. Set an incorrect position of one Anchor 

    Unintentionally, an anchor could be placed at the wrong position or placed just by an eye without a precise measurement.


    light-on (on) In a scenario where one Anchor is incorrectly placed (difference between real position and position in Sensmap), the Anchor will introduce an unwanted offset into the position calculation. If the mismatch between the real position and the one in Sensmap is too big, the Anchor can be excluded from position calculation because it introduces too much error. If this Anchor is set as Master, this might result in a highly inaccurate positioning performance.


  3. Set an incorrect scale of the floorplan 

    This is a very common mistake during the deployment phase is having an inaccurate floorplan. The plan itself may be inaccurate, or the scale can be set incorrectly. You can try the results of that by yourself

    1. Edit the Building in Sensmap and set an incorrect scale (two times bigger or less than the correct scale).

    2. Now, place an Anchor to the correct position on the updated floorplan (the physical distance between Anchors will be the same, but the distance between Anchors in Sensmap will be different). 

    3. Try to evaluate the results.


    The calculated positions will be visible in Sensmap but only in one part of the area depending on the position of the Master Anchor.





     Hint

    For each scenario, try and walk around with a Tag to compare the results, like in Section "Walking with the Tag".

    After each scenario, you can restore the system back into the original working state by using the Backup/Restore in RTLS Studio. 

    Using Aliases instead of MAC addresses to identify the Anchors will help you avoid some of the mistakes during placing the Anchors on the floorplan.



8. Experimenting with the Tags

TASK TIME: 90 MIN

A Tag placement and configuration is a key for any project. Typical tag placement is shown in picture below.

Tag placement

Rule of thumb: Put tag as high as possible on an object. Do not hide the tag behind materials which attenuate the radio signal like water, human body or metal parts.


Tag Configuration

It is important to understand use-case requirements i.e tracking a sport player require fast refresh rate without much care about battery lifetime, thus sleep mode can be disabled. While asset tracking requires very long battery lifetime and decent refresh rate in seconds or tens of second employing also the motion detection feature in order to preserve battery. 

Please read details about configurable tag motion detection and sleep modes.


We'll focus on two exercises, one will evaluate the Tag placement and the second on trying different Tag configurations. You migth observe a different performance with various configurations of the Tags, plus you'll also learn how to configure them. For example, different refresh rates will mean different density of positions in time.

A very common mistake with Tag configuration is when the sleep mode threshold is set. Low threshold means that the Tags can be woken up by a very slight movement with low force, with high threshold the situation is opposite and you need a higher acceleration to wake up the Tag. Also, it is quite common that the Tag is held in hand during testing. Subtle movements while the Tag is held in hand may cause that the Tag doesn't actually wake up, even when the threshold for sleep mode is Low. Because of that, it is recommended that the tests are performed with a disabled sleep mode, to void a situation when the Tag is sleeping unintentionally. 

Scenarios with various Tag configurations:

Please change the configuration of your Tags as follows, and evaluate the results by using the "Nodes Tracking Statistics" in Sensmap as shown in "Walking with the Tag":

  • IMU #1 - RR 200 ms / Sleep mode Immediately High 
  • IMU #2 - RR 1000 ms / Sleep mode Immediately Low
  • Picco #1 - RR 200 ms / Sleep mode Immediately Low 
  • Picco #2 - RR 1000 ms / Sleep mode immediately Low


 Hint

The Anchors and Tags should have the same Blink Profile and Channel. See Tag Wireless Configuration for more information.

The Anchors and Tags should have the same Blink Profile and Channel. See "Walking with the Tag" for more information.

Further information about sleep modes can be found in Motion Detection and Sleep Modes.



9. Experimenting with the Zones and WebSocket API

TASK TIME: 60 MIN

The zones are one of the most powerful feature of RTLS. They simply transform area into a smart space, where virtual geo zones and accurate positioning data allows to trigger API events. 

This exercise should help you understand more about the Zones feature and how to use the WebSocket API. It is split into two scenarios. The first scenario should help you understand how Zones work and how to obtain information about them through the WebSocket API. In this scenario, you can use various Tag configurations to compare the performance with different refresh rates and sleep modes while using Zones. The WebSocket API is the only connector to achieve real-time information about Zones (Entry/Exit information). The second scenario is used for the training evaluation.

Please create the RTLS Capture for each of those for evaluation of the training.

Scenario A: Subscription to the zones.

  • Please draw 3 zones (minimum dimensions is one meter), the distance between the Zones should be also one meter. For example:

     Hint

    For easier drawing of the Zones, you can enable the grid (1x1 meters) by pressing ALT+G

  • Set up WebSocket client via your browser (recommended is to use Chrome) and subscribe to the created Zones.
  • Make the RTLS Capture and store the output from the WebSocket API (to text file) for evaluation of a similar trajectory as shown on the figure below:

Scenario B: Performance evaluation. 

  • Divide your Location Area into two Zones. The distance between them should be one meter.

     Hint

    Corridor may not be exactly at the center. But it should not be on the edge of room.

  • Make the RTLS Capture for evaluation purposes of a trajectory shown in the picture below. If approximately 95% of the positions stay in the corridor, you will pass the L2 Training.


10. Factory restore - optional

After the training is finished, you should do a factory restore of your RTLS Studio and Anchors and Tags. This exercise will show you how to do that, in order to set the system into default. This process is important before making a demo or presentation to a customer, in order to make sure that the system is working properly.

  1. Factory restore of RTLS Studio - Optional
  2. Anchors - Recommended 
    1. Reset one Anchor to default. In case of a regular RTLS kit (no Wi-Fi), set the IP address  of the Anchor from the kit's IP range: 192.168.101 - 105. (See Anchor datasheet chapter 3 for more information).
    2. Rest of the Anchors should have their Blink Channel set back to the default (channel 5).
  3. Tags - Recommended
    1. The IMU Tags can be restored into default via console (See IMU Tag datasheet chapter 10 for more details)
    2. The Piccolino Tags can be restored into default via the user button (See Piccolino Tag datasheet chapter 1.1 for more information)