How to Synchronize a Honeywell HGuide n580 Navigator with a Velodyne HDL-32E or VLP-16 LiDAR Unit

Executive Summary

Honeywell has been producing high-performance inertial sensors for decades, delivering over 500,000 units for navigation aids across aircraft and spacecraft. Their HGuide inertial measurement units (IMUs) and navigators are utilized in various industrial applications, including agriculture, AUVs, communications, marine, robotics, and transportation.

The Honeywell HGuide n580 is a compact, lightweight, self-contained inertial navigation system (INS) combined with a global navigation satellite system (GNSS) navigator. It provides position and orientation data, even when GPS/GNSS signals are unavailable. The n580 features Honeywell's HG4930 IMU and dual-antenna, multi-frequency, multi-constellation real-time kinematic (RTK) capability, integrating IMU and GNSS data for robust navigation.

For mobile applications, such as collecting LiDAR data from moving platforms (cars, aerial vehicles), knowing the precise location and attitude of the scanner is crucial. This requires parameters like latitude, longitude, altitude, and attitude at the time the LiDAR data is valid. These parameters are essential for creating accurate 3D maps from point cloud data.

Synchronization Concept

To accurately merge INS/GNSS and LiDAR data, timestamps must be synchronized to a common reference clock, typically GPS time. This synchronization requires two key pieces of information from the INS/GNSS:

• A TTL level '1 pulse per second' (1PPS) signal, sent precisely every second.
• An NMEA $GPRMC message, containing the actual time of the 1PPS.

The HGuide n580's output messages and signal timing are designed for easy integration with Velodyne LiDAR scanners like the HDL-32E and VLP-16.

Diagram Description: A diagram illustrates the system architecture, showing GNSS antennas feeding into the HGuide n580. The HGuide n580 then provides a 1PPS signal and real-time GNSS data, including GPS time, to a Velodyne Interface Box, which connects to the Velodyne LiDAR Sensor.

Process to Set Up Sync

The Honeywell HGuide n580 Navigator provides the necessary $GPRMC and 1PPS signals via its IO2 port. The IO1 port typically handles data logging. While the 1PPS signal is always present and the $GPRMC message is usually enabled by default, users may need to re-enable it via configuration files or commands, as detailed in the HGuide n580 manual.

The following connections are required from the HGuide n580 to the Velodyne interface box:

• Signal: Ground, IO Port: 102, Pin Number: Pin 15, Pin Label: Ground, Color: Black
• Signal: $GPRMC Message, IO Port: 102, Pin Number: Pin 14, Pin Label: GPS Receive, Color: Blue
• Signal: 1PPS, IO Port: 102, Pin Number: Pin 9, Pin Label: GPS Pulse, Color: Green

It is also possible to bypass the interface box and connect directly to the Velodyne LiDAR unit.

After making these connections, power up the HGuide n580 and Velodyne LiDAR unit. Ensure the GNSS antennae have a clear view of the sky to acquire a satellite signal. Verify that the HGuide n580's GNSS board has achieved 'GNSS Lock' using the HGuide Data Reader program, indicated by the presence of latitude, longitude, and altitude data.

Diagram Description: A diagram shows the wiring connections between the HGuide n580 and the Velodyne Interface Box, specifying signal types, IO ports, pin numbers, and wire colors. Another diagram illustrates the HGuide n580 providing navigation data, including position and attitude, in a vehicle environment, highlighting its performance in GNSS-denied areas.

To confirm the connection, access the Velodyne hardware via Ethernet and use its Webserver User Interface by navigating to http://192.168.1.201. Once the PPS signal is 'Locked' and the GNSS position in the Velodyne software matches the HGuide data reader, users can begin logging both LiDAR and INS/GNSS data, ensuring concurrent timestamps for offline processing.

Diagram Description: Screenshots show the HGuide Data Reader displaying navigation status (position, attitude) and the Velodyne LiDAR Software User Interface confirming GPS Position and PPS 'locked' status.

Conclusion

Synchronizing the Honeywell HGuide n580 with Velodyne VLP-16 or HDL-32E LiDAR units is a straightforward process that enables users to align data logs. The HGuide n580 provides time-stamped position, velocity, angular rate, linear acceleration, roll, pitch, and heading. Its dual-antenna mode supports GNSS-based heading, and its broad input/output range facilitates easy interfacing with other sensors, including Velodyne LiDAR units.

For more information on the Honeywell HGuide n580, visit aerospace.honeywell.com/hguide. Further details on the Velodyne HDL-32E & VLP-16 Interface Box can be found in its manual.

About Honeywell Aerospace

Honeywell Aerospace develops and integrates thousands of products, software, and services to enhance transportation safety, efficiency, and comfort globally. Their offerings are present on nearly all commercial, defense, and space aircraft. They focus on innovative solutions for fuel efficiency, flight optimization, and advanced avionics.

In 2016, Honeywell expanded its IMU and navigator offerings with a new business unit, making class-leading products available without export licenses (ECCN = 7A994). This brings Honeywell's aerospace quality standards to a wider customer base at industrial pricing.

To learn more about Honeywell's HGuide IMUs and navigators, visit: aerospace.honeywell.com/hguide.

Talk to an Expert

For North America and South America:
Ray Sturm
Ray.S.Sturm@Honeywell.com
+1 6122804010

For Asia Pacific and the United Kingdom:
Darren Fisher
Darren.Fisher@Honeywell.com
+44 (0)7779970095

For Mainland Europe, the Middle East, Africa and India:
Theo Kuijper van der Duijn
Theo.KuijpervanderDuijn@Honeywell.com
+41 (0)1217117904

Author of this document:
Darren Fisher
Sales Manager
APAC and United Kingdom

Honeywell Aerospace
2600 Ridgway Parkway
Minneapolis MN 55413
aerospace.honeywell.com