Version 2024.04
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Vision-RTK 2
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Vision-RTK 2 Starter Kit
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The information contained herein is provided “as is” and Fixposition assumes no liability for its use. No warranty, either express or implied, is given, including but not limited to, with respect to the accuracy, correctness, reliability and fitness for a particular purpose of the information. This document may be revised by Fixposition at any time without notice. For the most recent documents, visit https://docs.fixposition.com/fd/.
Copyright © 2024, Fixposition AG
Technical data
Technical details
| Maximum output rate | 100Hz |
| Positioning accuracy (RTK Fix only) | 1.0 cm + 1 ppm R50 |
| Heading accuracy | 0.4° (1 m baseline) |
| Velocity accuracy | 0.1 m/s |
| Maximum velocity | 22 m/s |
| Position error as % if distance traveled in GNSS outages | 0.75 %1 |
| Acquisition time | 25 s (cold start) |
¹Automotive mode with wheel odometry input
Communication and configuration
| Data formats | NMEA, ROS1, ROS2, Fixposition messages, others |
| Operation modes | Automotive, Generic, Lawnmower, Ground robot |
| RTK correction format | RTCM3 |
| Data interfaces (input/output) | UART, TCP, CAN |
| Time synchronization | PPS, PTP, NTP |
Hardware
| Dual RTK receivers | Supported GNSS constellations • GPS/QZSS (L1C/A, L2C) • Galileo (E1B/C, E5B) • Beidou (B1I, B2I) • GLONASS (L1OF, L2OF) |
| Camera | CMOS with global shutter, 120° DFOV |
| IMU | Accelerometer and gyroscope |
| Internal storage | 16 GB flash memory |
| Time synchronization | PPS, PTP, NTP |
Interfaces
| Wired inputs/outputs | 2x UART, CAN, Ethernet, USB-C |
| Wireless | Wi-Fi 802.11 ac/a/b/g/n |
| GNSS antenna connector | 2x SMA |
| Camera inputs | 2x MIPI CSI-2 |
Electrical specifications
| Supply voltage range | 5-36 V DC |
| Typical power consumption | 10 W |
Mechanical specifications
| Dimensions (L × W × H) | 114 × 129 × 30 mm |
| Weight | 420g |
Environmental specifications
| Operating temperature | -30°C to +85°C |
| Certifications | IP66 – water and dust resistance |
Setup overview
- Power on the Vision-RTK 2 (Step 1) and connect to the sensor over Ethernet or Wi-Fi (Step 2)
Ethernet 10.0.2.1 Wi-Fi 10.0.1.1 SSID fp-xxxxxx password 1234567890 
- Provide internet access to the Vision-RTK 2 (Step 3)
- Provide RTK corrections via NTRIP (Step 4)
- Head into an open area with a clear view of the sky to achieve an RTK fixed on both GNSS receivers (Step 7)
- Start the Fusion engine (Step 9) and perform IMU calibration (Step 10)
Step 1: Power on the Vision-RTK 2
- To power on the Vision-RTK 2, either:
A. Connect the Vision-RTK 2 to an external power supply
B. Connect the battery provided with the starter kit
- To power off the Vision-RTK 2, simply disconnect the power supply
Additional information
- Ensure the power cable is securely fastened to the Vision-RTK 2.
- The power supply must be able to deliver 10 W at a 5-36 V voltage. The absolute maximum ratings are -14 V to 40 V, and operating conditions are 4.5 V to 36 V.
- Do not disconnect the power while recording, as information might be lost. After stopping a recording, wait at least 15 seconds before powering down.
- While it is possible to power the Vision-RTK 2 via the USB-C port, it is not recommended to do so during operation.
Step 2: Connect to the Web-interface
- Connect the Vision-RTK 2 either via:
A. Ethernet (recommended)
◦ Connect the provided Ethernet cable to your network
◦ Open the browser and visit http://10.0.2.1/ or http://fp-xxxxxx.local/
B. Wi-Fi
◦ Plug the provided Wi-Fi antenna to the Vision-RTK 2
◦ Connect to the Wi-Fi SSID fp-xxxxxx using the default password 1234567890
◦ Open the browser and visit http://10.0.1.1/ or http://fp-xxxxxx.local/
Additional information
- Wi-Fi is only suitable as a service interface. Use Ethernet for regular operation
- Connect the Wi-Fi antenna as the range without it is limited to only half a meter
- To change the Wi-Fi hotspot password, refer to Section 5.2.6 of the Integration manual. To set up a password for the web interface, refer to Section 5.14
- When employing an intermediary device, such as a router, configure the sensor as a DHCP client. The network’s DHCP server will assign a dynamic IP to the sensor. Thus, the 10.0.1.1 and 10.0.2.1 IPs do not apply anymore
- To configure a static IP, please refer to Section 5.2.7 of the Integration manual
Step 3: Configure network
GNSS corrections for the Vision-RTK 2 are typically delivered over the internet, which necessitates connectivity to a network with internet access.
- Navigate to Configuration ↪ Network
- Establish a network connection over:
A. Ethernet (recommended)
◦ Connect the Vision-RTK 2 to the desired network
◦ Set the Vision-RTK 2 as DHCP client or DHCP server depending on the network topology
B. Wi-Fi
◦ Select the active Wi-Fi band (2.4 or 5 GHz)
◦ On the Wi-Fi client tab, click Add Wi-Fi connection
◦ Search for available networks, select one, and type in the password to connect
◦ Wait until the connection is established (the label “Connected” will appear)
Additional information
- The Vision-RTK 2 can only access the Internet if set as a DHCP client or with an static IP
- An Ethernet connection is always prioritized over Wi-Fi for Internet access
- Set the network as default to automatically reconnect to it after a disconnection or reboot
- 2.4 GHz is preferred over 5 GHz for Wi-Fi connections due to its range and reliability
- The only supported Wi-Fi security configuration is wpa-psk (WPA2)
- The network SSID must be alphanumeric
- Most Wi-Fi 6E access points use 802.11ax by default, which is not supported. It must be configured to one of the supported bands
Step 4: Configure GNSS corrections
- Navigate to Configuration ↪ GNSS
- Select a source for corrections among:
A. NTRIP client (recommended)
◦ Fill in the required configuration fields (optionally, can also be be filled using a path)
B. I/O port
◦ Send appropriate RTCM3 messages to any I/O port. In this configuration, the built-in NTRIP client is disabled, and the sensor does not need an Internet connection
C. TCP client
◦ Connect to any TCP/IP host that provides the appropriate RTCM3 messages. In this configuration, the sensor does not need an Internet connection
Additional information
- The geodetic coordinate system is defined by the correction service provider
- Ensure that your selected correction stream has a base-station nearby (ideally closer than 15km) or good VRS coverage
- For more information, refer to Section 5.5 of the Integration manual
Step 5: Configure the Fusion engine
- Navigate to Configuration ↪ Fusion
- Select the tuning mode based on the following table
Mode Application v range ω Range Generic Default mode that covers most platforms’ dynamics ± 3 m/s ± 1.5 rad/s Slow robot Dynamics similar to that of a slow-moving robot ± 3 m/s ± 0.5 rad/s Lawnmower Dynamics similar to that of a lawnmower ± 3 m/s ± 1.0 rad/s Car Dynamics similar to that of a passenger car ± 22 m/s ± 0.5 rad/s - Set the GNSS antenna extrinsics within millimeter accuracy
Additional information
- Enabling wheel-speed sensor is recommended for optimal performance
- If using the Starter Kit, select the Standard Starter Kit preset to retrieve the extrinsics
- The Autostart option enables the Fusion Engine to initialize automatically on system boot-up
- If the baseline check error pop-up appears, please verify your GNSS extrinsics and check that the selected base-station is closer than 25km (refer to Section 5.13 of the Integration manual)
- The GNSS extrinsics are set relative to the ‘X’ on the sensor
- The antenna reference point refers to its phase center (see antenna datasheet)
Step 6: Configure output
- Navigate to Configuration ↪ I/O to the Output generators section
- Set the Output frequency (Hz), Output translation (m), and Output rotation (degrees)
- Navigate to Output messages section and select the desired messages and output channels
Additional information
- The output translation is set relative to the ‘X’ on the sensor
- The high-precision NMEA format contains non-standard fields which allow higher precision in the timing, position, and heading values
- A higher output frequency requires a higher I/O bandwidth. For example, IMU messages require significant bandwidth and should be enabled with discretion
- All available messages are documented at https://docs.fixposition.com/fd/i-o-messages
- For the LLH output, the sensor assumes that the correction data employs the WGS84 geodetic datum
- Enabling more messages will consume more CPU resources and might impact the sensor’s performance. Only enable them when necessary, preferably on one port only
Step 7: Check GNSS status
- Navigate to Status ↪ GNSS
- Ensure the correction data is connected and stable
- Ensure both of the GNSS receivers to be of “RTK Fixed” status
Additional information
- Initialize outdoors, as some casters require an initial position estimate to provide corrections
- Most signals should ideally be above 42 dBHz
- Antenna state and power should be OK and On
- If an RTK fixed is not achieved in less than two minutes, move away from obstructions, ensure no USB3 devices or unshielded cables are near the GNSS antennas, and verify that your selected base-station is closer than 25km
Step 8: Check camera view
- Navigate to Configuration ↪ Camera
- Ensure that feature-sparse regions and static objects (e.g., vehicle’s structure) are cropped from the image
Additional information
- The auto-exposure of the camera is affected by the crop mask
- The sensor can look forwards or backwards
- Employ an external lighting source if working in low-lighting conditions
Step 9: Start the Fusion engine
- Navigate to Status ↪ Fusion
- Click the Start button and head into an open area with a clear view of the sky to achieve an “RTK fixed” on both GNSS receivers. This process should take less than 2 minutes
- Ensure that all message outputs on the status page are activated and the arrow in the map is accurately indicating the heading of the sensor
| Output | StdDev | |
Position  |
47° 24′ 1.0727″ N | 14.150 m |
| 8° 27′ 1.3247″ E | 14.145 m | |
| 459.44m | 14.146 m | |
| Orientation |  |
8.32º yaw |
| 3.80º pitch | ||
| 8.31º roll | ||
| Velocity (2d) | 0.00 m/s | |
Step 10: Calibrate the IMU
The Vision-RTK 2 requires a start-up procedure before being fully operational. The user must ensure the following requirements are fulfilled to start the calibration procedure:
- Ensure both receivers obtain RTK fixed status
- Start the Fusion engine, and ensure extrinsics are correct
- Move the sensor under RTK fixed status with some dynamic motion
▪ Move in the shape of eight roughly sized at 10m
▪ Move back-and-forth a few times over a stretch of 10m
- Calibrate until IMU biases are converged (IMU status must show “Converged”)
Additional information
- After converging, the IMU biases will be saved to be used on the next initialization procedure. Thus, the calibration will be significantly faster
- The IMU biases will continue to be estimated any time the sensor is under ”RTK fixed”
- IMU’s “Excessive noise” only indicates that the measurements present significant mechanical vibrations; however, this is not necessarily noise (e.g., moving on rocky terrain)
Data logging and customer support
- Navigate to System ↪ Logs
- Choose the logging location
A. Internal disk: Embedded memory, max. around 6 GB (up to ~20min of “Maximal“ recording)
B. External USB: Storage connected to USB-C port. May consume additional CPU resources - Choose the logging level
A. Minimal: Smallest file, only minimal data (no GNSS or camera)
B. Medium: Larger file, does not contain images.
C. Maximal: Largest file, contains all data (incl. images). Allows to reprocess the trajectory - Retrieve the logs from the web-interface by clicking on the log name
- Get support
A. Browse the Vision-RTK 2 Documentation for rich description of all features
B. Email support@fixposition.com to get access to the Fixposition Dashboard, and upload the log files to the Fixposition Data Uploader¹ to accelerate debugging and analyze the sequence
C. Report other technical issues at Fixposition JIRA platform
D. Request customer support at support@fixposition.com
¹All shared data is visible only to the uploader, the uploader’s company domain (if explicitly asked to do so), and selected Fixposition employees.
Software update
- Navigate to System ↪ Update
- Drag/drop the corresponding SWU file inside the marked area.
- Wait for a few minutes for the update to process. The sensor will automatically restart after the update is completed
Additional information
- Software updates are released at Current Software Version
- Software updates are released every 6-10 weeks. Please email support@fixposition.com to be added to the distribution list
Documents / Resources
 |
FIXPOSITION Vision-RTK 2 Starter Kit [pdf] User Guide Vision-RTK 2 Starter Kit, Vision-RTK, 2 Starter Kit, Starter Kit, Kit |
