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Configure Tracelet

This section shows how to configure the Tracelet parameters.

UWB Site Origin

The Tracelet can translate UWB site coordinates into WGS84 coordinates. For that the Site latitude, longitude and azimuth must be configured.

Enter these values in fuse-origin parameter.

You can get the parameters from Easyplan: Use the "View" feature of the site. A JSON file will be stored in your download folder. In the JSON, look for

Easyplan building view

    "originAzimuth": xxx,
    "originLatitude": yyy,
    "originLongitude": zzz,

GNSS RTK Correction Data Source

RTK corection data is required to achieve high accuracy. Correction data may come:

  • from NTRIP service providers, delivering RTCM correction data, such as Sapos or rtk2go.
  • from UBLOX pointperfect, delivering SPARTN correction data.
  • from a local RTK Base station + self hosted NTRIP server.

In all cases, ensure the device can reach the correction data source and configure the ntrip-caster and ntrip-credentials parameters accordingly.

Note

PointPerfect users may notice a position offset on some maps. See the Thingstream knowledge base article for details.

Using GNSS Sensor Fusion

In GNSS Sensor Fusion mode, the device uses a dynamic model of the vehicle, integrated IMU, and optionally the external wheeltick to further improve the precision, especially in cases with bad GNSS receiption conditions.

To enable GNSS Sensor Fusion mode generally:

  • Configure the type of vehicle in parameter dynmodel to automotive for automotive vehicles, like cars or trucks, and rail for railway vehicles, like trams.
  • Configure the alignment of the IMU to the vehicle
  • Configure the lever arms
  • Configure the wheeltick
  • set the dr configuration parameter to on.

Lever Arm

The dynamic model for sensor fusion requires the configuration of the lever arm:

  • the lever arm from the IMU to the vehicle rotation point (VRP). Because the IMU is inside the tracelet, it can also be read as traclet-to-VRP.

The VRP is defined as the point where the vehicle rotates around. * For a car, it is the rear axle. * For a train, this is the center between two bogies.

The configuration parameters are: * imu2vrp_x, imu2vrp_y, imu2vrp_z for the IMU to VRP lever arm

All parameters are specified in centimeters.

Mount Alignment

For sensor fusion, the alignment of the IMU to the vehicle is important.

If you mount the tracelet as shown below, you can leave the alignment parameters at their default values (0:0:0). Tracelet orientation

If the tracelet is not aligned 1:1 there are two possibilities: * auto-alignment: the device will try to determine the alignment automatically. This is the default. Set the ubx_mntalg parameter to an empty string to enable auto-alignment. * manual alignment: the alignment can be configured using the ubx_mntalg parameter. The value is a 3-tuple, specifying yaw (0..360), pitch (-90..90), and roll (-180..180) in degrees, e.g. 0:0:0 for no alignment.

For more information, refer to the UBlox Integration Manual.

Wheel Tick

If the vehicles wheeltick signal is connected to the device, the wheeltick signal can be used to improve the precision of the positioning.

The number of ticks per kilometre must be configured via the tacho_k parameter.

Warning

The current firmware uses a fixed wheeltick rate of 4000 ticks/km. Changing the rate requires a different firmware image and matching tacho_k value—contact Ci4Rail if you need an alternative.

To enable wheel tick usage, set ubx_wt_dir to 1:0:0:0. To disable wheeltick usage (if you don't have a wheeltick), set it to 0:0:0:0.

Localization Server Address

Tell the Tracelet where to send the position messages to. Enter the address and port of your localization server. To find out your PC's address, open a command prompt and enter ipconfig. Look for the IPv4 address of your active WLAN network connection (e.g., 192.168.55.100).

The port of the Localization server is 11001.

Set the parameter loc-srv to <your_pc_ip>:11001.

Device Configuration

The device parameters mentioned above can be configured either via USB console or via the network.

All parameters are stored in non-volatile memory. Restart the device after applying changes—for example by entering reboot in the USB console or issuing a restart command over the network.

Info

Parameters persist across reboots, but changes only take effect after a restart.

Setting parameters via network

To set parameters via network, use the io4edge-cli tool. Device management documentation explains how to download and operate it.

To apply a set of parameters, use the provided sio02-params-demo.yaml file (part of the lyve-demokit repo) as a starting point and change all parameters according to your needs.

Afterwards, apply them with 

c:\work\io4edge-cli\io4edge-cli -i 192.168.55.2:9999 set-parameter -f sio02-params-demo.yaml
c:\work\io4edge-cli\io4edge-cli -i 192.168.55.2:9999 restart

Setting Parameters via USB Console

Only necessary in case you can't reach the device via network! In this case connect a USB-A cable to the breakout adapter EVU04, start a terminal program on your PC, such as MobaXterm, and connect it with the serial port at baudrate 115200.

You should see some log messages of the device. Press ENTER and the device will present a config> prompt. Enter the commands to configure the device.

For example, to enable sensor fusion, you would enter:

config> dr on

Info

Use the help command for a list of console commands. Some options are intended only for development.

See also general io4edge device configuration.

Parameter List

The following table lists the user relevant parameters of the device:

Parameter Description Default Example
wifi-ssid SSID of the Wi-Fi network to connect to "" MyWiFi
wifi-pw Password of the Wi-Fi network to connect to "" MyWiFiPassword
device-id Use to identify the device in the network and used for traceled_id in the position message "" TRACELET-DEMO
loc-srv Address of the localization server to send position messages to "" 192.168.0.88:11001
ntp-srv Address of the NTP server to get time from pool.ntp.org pool.ntp.org
ntrip-caster Address of the NTRIP caster to get correction data from (host:port:mountpoint) "" rtk2go.com:2101:LAU01DE
ntrip-credentials Credentials for the NTRIP caster (username:password) "" info@ci4rail.com:none
gnss-rate Rate of GNSS position messages in Hz, 1..4Hz 1 3
fuse-rate Rate of fused position messages in Hz, 1..4Hz. Set it to the same value as `gnss-rate 1 3
fuse-origin UWB Site origin and azimuth (lat:lon:azi) "" 48.1748314:11.5287476:0.8900383
dr Enable GNSS sensor fusion on on
dynmodel Dynamic model of the vehicle (rail, automotive) automotive rail
imu_mntalg Manual alignment of the device to the vehicle (yaw:pitch:roll). If parameter is not set, use auto mount alignment "" -90:0:0
imu2vrp_x, imu2vrp_y, imu2vrp_Z Lever arm from IMU to VRP in cm 0 100
uwb_z Tracelet mounting height (to floor) in cm 0 280
tacho_k Number of ticks per km for the wheeltick signal 0 4000
ubx_wt_dir Enable wheeltick usage (1:0:0:0) or disable wheeltick usage (0:0:0:0) 0:0:0:0 1:0:0:0
uwb_radio UWB channel to use (5 or 9) - Must be 9 for LYVE Demokit Rev. 0 5 9