NovAtel GPS Driver

Overview

This is a C++ ROS driver for NovAtel GPS / GNSS Receivers.

Features:

• Fast and robust
• Supports serial, TCP, and UDP connections
• Can play back PCAP capture logs to test behavior
• Supports a variety of common NovAtel logs
• Easy to add support for more log types
• Supports ASCII and binary-format NovAtel logs
• Can synchronize BESTPOS, BESTVEL, and PSRDOP2 logs together in order to produce gps_common/GPSFix messages
• Tested with OEM4, OEM6, and OEM7 receivers
• Can produce IMU data from receives with SPAN support

It has been tested primarily on NovAtel OEM628 receivers, but it has been used with various OEM4, OEM6, and OEM7 devices. Please let the maintainers know of your success or failure in using this with other devices so we can update this page appropriately.

Usage

The driver should function on ROS 2 Dashing, and binary packages are available for both of them. To install them, first install ROS, then just run:

sudo apt-get install ros-dashing-novatel-gps-driver

If you’d like to build it from source:

mkdir -p novatel/src
cd novatel/src
git clone https://github.com/swri-robotics/novatel_gps_driver
rosdep install . --from-paths -i
cd ../..
colcon build

Then create a .launch.py file and configure it as desired:

"""Launch an example driver that communicates using TCP"""

from launch import LaunchDescription
import launch_ros.actions


def generate_launch_description():
    container = launch_ros.actions.ComposableNodeContainer(
        name='novatel_gps_container',
        namespace='',
        package='rclcpp_components',
        executable='component_container',
        composable_node_descriptions=[
            launch_ros.descriptions.ComposableNode(
                package='novatel_gps_driver',
                plugin='novatel_gps_driver::NovatelGpsNode',
                name='novatel_gps',
                parameters=[{
                    'connection_type': 'serial',
                    'device': '/dev/ttyUSB0',
                    'verbose': True,
                    'publish_novatel_positions': True,
                    'publish_novatel_velocity': True,
                    'publish_novatel_psrdop2': True,
                    'frame_id': '/gps'
                }]
            )
        ],
        output='screen'
    )

    return LaunchDescription([container])

gps_common/GPSFix messages will always be published, but by default, other message types are not. See the config parameters for a list of which other message types can be enabled.

Packages

1. novatel_gps_msgs

   ROS messages that represent NovAtel message logs. Each supported log should have its own message type. A list of official log types can be found at http://docs.novatel.com/OEM7/Content/Logs/Log_Reference.htm .

2. novatel_gps_driver

   A C++ library with an accompanying ROS node and node that can connect to a NovAtel device over a serial, TCP, or UDP connection and translate NovAtel logs into ROS messages.

Nodelets

1. novatel_gps_driver/novatel_gps_nodelet

   1. ROS Parameters
      • connection_type: Type of physical connection to the device
        • One of serial, tcp, udp, or pcap
        • Default: serial
      • device: Location of device connection.
        • For serial connections, the device node; e. g., /dev/ttyUSB0
        • For tcp or udp connections, a host:port specification.
          • If the host is omitted, it will listen for connections on the specified port.
          • If the port is omitted, 3001 will be used as the default for TCP connections and 3002 as the default for UDP connections.
        • For pcap connections, the location of a .pcap capture file. Note that the node will exit automatically after finishing playback.
        • Default: Empty
      • frame_id: ROS TF frame to place in the header of published messages.
        • Default: Empty
      • imu_frame_id: TF frame id to use in IMU messages.
        • Default: Empty
      • imu_rate: Desired logging rate in Hz for IMU messages.
        • This is set as the rate for CORRIMUDATA logs.
        • Default: 100
      • imu_sample_rate: Sample rate of the connected IMU. Normally this is automatically detected based on the IMU type.
      • polling_period: Desired period between GPS messages.
        • This will be set as the period for GPGGA, GPRMC, GPGSA, BESTPOS, and BESTVEL logs.
        • Default: 0.05 (20 Hz)
      • expected_rate: Expected publish rate of GPS messages.
        • If time between GPS message stamps is greater than 1.5 times the excepted publish rate, diagnostic warning is published.
        • Default: Based on polling_period parameter: 20.0 (20Hz)
      • publish_clocksteering: true to publish novatel_gps_msgs/ClockSteering messages.
        • Default: false
      • publish_diagnostics: true to publish node diagnostics.
        • Default: true
      • publish_gpgsa: true to publish novatel_gps_msgs/Gpgsa messages.
        • Default: false
      • publish_gpgsv: true to publish novatel_gps_msgs/Gpgsv messages.
        • Default: false
      • publish_gphdt: true to publish novatel_gps_msgs/Gphdt messages.
        • Default: false
      • publish_imu_messages: true to publish novatel_gps_msgs/NovatelCorrectedImuData, novatel_gps_msgs/Inspva, novatel_gps_msgs/Inspvax, novatel_gps_msgs/Insstdev, and sensor_msgs/Imu messages.
        • Default: false
      • publish_nmea_messages: true to publish novatel_gps_msgs/Gpgga and novatel_gps_msgs/Gprmc messages.
        • Default: false
      • publish_novatel_dual_antenna_heading: true to publish novatel_gps_msgs/NovatelDualAntennaHeading messages.
        • Default: false
      • publish_novatel_heading2: true to publish novatel_gps_msgs/Heading2 messages.
        • Default: false
      • publish_novatel_positions: true to publish novatel_gps_msgs/NovatelPosition messages. Note that even if this is false, these logs will always be requested from the receiver in order to generate gps_msgs/GPSFix messages.
        • Default: false
      • publish_novatel_psrdop2: true to publish novatel_gps_msgs/NovatelPsrdop2 messages. If set, the data from these messages will be used to fill in the DoP values in gps_msgs/GPSFix messages. Note that these messages are only published when the values change, not at the standard polling rate.
        • Default: false
      • publish_novatel_utm_positions: true to publish novatel_gps_msgs/NovatelUtmPosition messages.
        • Default: false
      • publish_novatel_velocity: true to publish novatel_gps_msgs/NovatelVelocity messages. If set, the data from these messages will be used to fill in the speed and track values in gps_msgs/GPSFix messages.
        • Default: false
      • publish_novatel_xyz_positions: true to publish novatel_gps_msgs/NovatelXYZ messages.
        • Default: false
      • publish_range_messages: true to publish novatel_gps_msgs/Range messages.
        • Default: false
      • publish_sync_diagnostic: If true, publish a time Sync diagnostic.
        • Ignored if publish_diagnostics is false.
        • Default: true
      • publish_dual_antenna_diagnostic: If true, publish diagnostics for the second antenna.
        • Ignored if publish_diagnostics is false.
        • Default: same as publish_novatel_dual_antenna_heading
      • publish_time_messages: true to publish novatel_gps_msgs/Time messages.
        • Default: false
      • publish_trackstat: true to publish novatel_gps_msgs/Trackstat messages.
        • Default: false
      • publish_invalid_gpsfix: true to publish the /gps topic, even if the status of the GPS fix is STATUS_NO_FIX.
        • Default: false
      • reconnect_delay_s: Second delay between reconnection attempts.
        • Default: 0.5
      • serial_baud: Select the serial baud rate to be used in a serial connection.
        • Default: 115200
      • spam_frame_to_ros_frame: Translate the SPAN coordinate frame to a ROS coordinate frame using the VEHICLEBODYROTATION and APPLYVEHICLEBODYROTATION commands.
        • Default: false
      • use_binary_messages: true to request binary NovAtel logs, false to request ASCII.
        • Binary logs are much more efficient and effectively required for IMU data, but ASCII logs are easier to parse for a human.
        • Default: false
      • wait_for_sync: true in order to wait for both BESTPOS and BESTVEL messages to arrive before publishing gps_msgs/GPSFix messages. If this is false, GPSFix messages will be published immediately when BESTPOS messages are received, but a side effect is that the driver will often be unable to fill in the speed & track fields. This has no effect if publish_novatel_velocity is false.
        • Default: true
   2. ROS Topic Subscriptions
      • /gps_sync (std_msgs/Time): (optional) Timestamped sync pulses from a DIO module. These are used to improve the accuracy of the time stamps of the messages published.
   3. ROS Topic Publications
      • /bestpos (novatel_gps_msgs/NovatelPosition): BESTPOS logs
      • /bestutm (novatel_gps_msgs/NovatelUtmPosition): BESTUTM logs
      • /bestvel (novatel_gps_msgs/NovatelVelocity): BESTVEL logs
      • /bestxyz (novatel_gps_msgs/NovatelXYZ): BESTXYZ logs
      • /clocksteering (novatel_gps_msgs/ClockSteering): CLOCKSTEERING logs
      • /corrimudata (novatel_gps_msgs/NovatelCorrectedImuData): CORRIMUDATA logs
      • /diagnostics (diagnostic_msgs/DiagnosticArray): ROS diagnostics
      • /dual_antenna_heading (novatel_gps_msgs/NovatelDualAntennaHeading): DUALANTENNAHEADING logs
      • /fix (sensor_msgs/NavSatFix): GPSFix messages converted to NavSatFix messages
      • /gpgga (novatel_gps_msgs/Gpgga): GPGGA logs
      • /gpgsa (novatel_gps_msgs/Gpgsa): GPGSA logs
      • /gpgsv (novatel_gps_msgs/Gpgsv): GPGSV logs
      • /gprmc (novatel_gps_msgs/Gprmc): GPRMC logs
      • /gps (gps_msgs/GPSFix): Fixes produced by combining BESTVEL, PSRDOP2 and BESTPOS messages together
        • Note: GPSFix messages will always be published regardless of what other types are enabled.
      • /heading2 (novatel_gps_msgs/NovatelHeadin2): HEADING2 logs
      • /imu (sensor_msgs/Imu): CORRIMUDATA logs converted to Imu messages
      • /inspva (novatel_gps_msgs/Inspva): INSPVA logs
      • /inspvax (novatel_gps_msgs/Inspvax): INSPVAX logs
      • /insstdev (novatel_gps_msgs/Insstdev): INSSTDEV logs
      • /psrdop2 (novatel_gps_msgs/Psrdop2): PSRDOP2 logs
      • /range (novatel_gps_msgs/Range): RANGE logs
      • /rosout (rosgraph_msgs/Log): Console output
      • /time (novatel_gps_msgs/Time): TIME logs
      • /trackstat (novatel_gps_msgs/Trackstat): TRACKSTAT logs

Adding New Logs

Do you need support for a new log type? Follow these steps:

1. Find the log reference in the official documentation.
2. Add a new .msg file to the novatel_gps_msgs package.
3. Add a new class in the novatel_gps_driver package that extends the novatel_gps_driver::MessageParser class that can parse the log and return the appropriate ROS message.
   1. Note that most MessageParsers produce UniquePtrs to messages because this is more efficient for intraprocess communications. Some MessageParsers have to produce SharedPtrs because multiple references to their messages are kept for synchronization or other purposes. Choose the appropriate pointer type based on your needs and look at other messages as examples.
4. Modify the novatel_gps_driver::NovatelGps class:
   1. Add an instance of your parser, a buffer for storing parsed messages, and a method for retrieving them.
   2. Modify the NovatelGps::ParseBinaryMessage, NovatelGps::ParseNovatelSentence, or NovatelGps::ParseNmeaSentence methods to use your parser to parse the new message type and store it in the appropriate buffer.
5. Modify the novatel_gps_driver::NovatelGpsNodelet class:
   1. Add a configuration parameter to enable the new message type.
   2. Add a publisher for publishing it.
   3. Modify NovatelGpsNodelet::CheckDeviceForData to retrieve messages from the appropriate buffer and publish them.
6. Add a new unit test to novatel_gps_driver/tests/parser_tests.cpp to test your parser.