NovAtel GPS Driver

1. Overview

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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 GPGGA, GPRMC, and BESTPOS logs together in order to produce gps_common/GPSFix messages
• Compatible with OEM6, OEM7, and SPAN receivers

It has been tested primarily on NovAtel OEM628 receivers, but in theory it should work with any OEM6, OEM7, or SPAN device. Please let us know of your success or failure in using this with other devices so we can update this page appropriately.

2. Usage

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The driver should function on ROS Indigo, Jade, Kinetic, and Lunar, and will hopefully soon be provided in the binary package repositories.

In the meantime, to build it from source using catkin_tools:

mkdir -p novatel/src
cd novatel
catkin init
catkin config --cmake-args -DCMAKE_BUILD_TYPE=RelWithDebInfo
cd src
git clone https://github.com/swri-robotics/novatel_gps_driver
rosdep install . --from-paths -i
catkin build

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

<?xml version="1.0"?>
<launch>
  <node name="novatel"
        pkg="nodelet" type="nodelet"
        args="standalone novatel_gps_driver/novatel_gps_nodelet">
    <rosparam>
      connection_type: serial
      device: /dev/ttyUSB0
      frame_id: /gps
    </rosparam>
  </node>
</launch>

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.

3. Packages

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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 nodelet and node that can connect to a NovAtel device over a serial, TCP, or UDP connection and translate NovAtel logs into ROS messages.

3. Nodelets

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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
      • gpgga_gprmc_sync_tol: Tolerance (in seconds) for synchronizing GPGGA and GPRMC logs.
        • Default: 0.01
      • gpgga_position_sync_tol: Tolerance (in seconds) for synchronizing GPGGA and BESTPOS logs.
        • Default 0.01
      • imu_frame_id: TF frame id to use in IMU messages.
        • Default: Empty
      • imu_rate: Desired rate in Hz for IMU messages.
        • This is set as the rate for CORRIMUDATA logs.
        • Default: 100
      • 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)
      • publish_diagnostics: true to publish node diagnostics.
        • Default: false
      • 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_imu: true to publish novatel_gps_msgs/NovatelCorrectedImuData, novatel_gps_msgs/Inspva, 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_positions: true to publish novatel_gps_msgs/NovatelPosition messages.
        • Default: false
      • publish_novatel_velocity: true to publish novatel_gps_msgs/NovatelVelocity 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_time_messages: true to publish novatel_gps_msgs/Time messages.
        • Default: false
      • publish_trackstat: true to publish novatel_gps_msgs/Trackstat messages.
        • Default: false
      • reconnect_delay_s: Second delay between reconnection attempts.
        • Default: 0.5
      • 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_position: true in order to wait for BESTPOS logs before publishing GPSFix messages.
        • Default: false
   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
      • /bestvel (novatel_gps_msgs/NovatelVelocity): BESTVEL logs
      • /corrimudata (novatel_gps_msgs/NovatelCorrectedImuData): CORRIMUDATA logs
      • /diagnostics (diagnostic_msgs/DiagnosticArray): ROS diagnostics
      • /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_common/GPSFix): Fixes produced by combining GPGGA, GPRMC, and BESTPOS messages together
        • Note: GPSFix messages will always be published regardless of what other types are enabled.
      • /imu (sensor_msgs/Imu): CORRIMUDATA logs converted to Imu messages
      • /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

2. Adding New Logs

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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.
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.