Overview

ROS driver for all of Microstrain's current G and C series products.

Supported Devices

3DM-GQ7, 3DM-CV7, 3DM-GX5-45, 3DM-GX5-25, 3DM-GX5-15

Installation

Buildfarm

This package is being built and distributed by the ROS build farm. If you do not need to modify the source, it is recommended to install directly from the buildfarm by running the following commands where ROS_DISTRO is the version of ROS you are using such as noetic or humble:

Driver:

sudo apt-get update && sudo apt-get install ros-ROS_DISTRO-microstrain-inertial-driver

Docker

The microstrain_inertial_driver is distributed as a docker image. More information on how to use the image can be found on DockerHub.

Source

For more info on source code and how to build from source, visit the Source section of our README.md on our microstrain_inertial GitHub page.

For more information on the ROS distros and platforms we support, please see our index.ros.org page.

Usage

Configure Parameters

This node uses a params.yml file for ease of configuration. This file contains all available parameters for the node, so please refer to that file for more information on the available parameters and how to use them.

Override Parameters for ROS

1. Copy and paste the line(s) you desire to change from params.yml into a new .yml file. We will call it /home/user/my_params.yml for this example. This new .yml file will override the default params.yml and if there are multiple lines of the same parameter, the last instance of the parameter will take precedence.

2. Launch the driver and specify the new params file:

roslaunch microstrain_inertial_driver microstrain.launch params_file:=/home/user/my_params.yml

Override Parameters for ROS2

1. Copy the file empty.yml to a new .yml file. For this example we will call the new file /home/user/my_params.yml. This new .yml file will override the default params.yml and if there are multiple lines of the same parameter, the last instance of the parameter will take precedence.

2. Copy and paste the line(s) you desire to change from params.yml into /home/user/my_params.yml.

3. Launch the driver and specify the new params file:

ros2 launch microstrain_inertial_driver microstrain_launch.py params_file:=/home/user/my_params.yml

Publishers

See below for a mapping between the ROS topics and messages to the MIP messages that populate them

Standard ROS Messages

The following topics contain standard ROS messages often used by other nodes. Sensor data is often massaged or converted to be fit into what the ROS standards dictate.

• /imu/data_raw sensor_msgs/Imu

  • angular_velocity -> Scaled Gyro(0x80, 0x05)

  • linear_acceleration -> Scaled Accel (0x80, 0x04)

    • The x,y,z values reported by the device are in Gs, but are converted to m/s^2 for ROS.

• /imu/data sensor_msgs/Imu

  • orientation -> Complementary Filter Quaternion (0x80, 0x0A)

  • angular_velocity -> Delta Theta (0x80, 0x07)

    • This measurement is the delta theta, so it is divided by the time since it was last sampled

  • linear_acceleration -> Delta Velocity(0x80, 0x08)

    • The x,y,z values reported by the device are in Gs, but are converted to m/s^2 for ROS.
    • This measurement is the delta velocity, so it is divided by the time since it was last sampled.

• /imu/mag sensor_msgs/MagneticField

  • magnetic_field -> Scaled Mag (0x80, 0x06)

• /imu/pressure sensor_msgs/FluidPressure

  • fluid_pressure -> Scaled Pressure (0x80, 0x17)

    • The device reports data in mBar, but the data is converted into Pascals for ROS.

• /imu/wheel_speed geometry_msgs/TwistWithCovarianceStamped

  • twist.twist.linear.x -> Odometer Data (0x80, 0x40)

  • twist.covariance[0] -> Odometer Data (0x80, 0x40)

• /gnss_1/llh_position sensor_msgs/NavSatFix -> GNSS LLH Position (0x91, 0x03)

• /gnss_1/velocity geometry_msgs/TwistWithCovarianceStamped -> GNSS NED Velocity (0x91, 0x05)

• /gnss_1/velocity_ecef geometry_msgs/TwistWithCovarianceStamped -> GNSS ECEF Velocity (0x91, 0x06)

• /gnss_1/odometry_earth nav_msgs/Odometry

  • pose -> GNSS ECEF Position (0x91, 0x04)

  • twist -> GNSS ECEF Velocity (0x91, 0x06)

• /gnss_1/time sensor_msgs/TimeReference -> GPS Timestamp (0x91, 0xD3)

• /gnss_2/llh_position sensor_msgs/NavSatFix -> GNSS LLH Position (0x92, 0x03)

• /gnss_2/velocity geometry_msgs/TwistWithCovarianceStamped -> GNSS NED Velocity (0x92, 0x05)

• /gnss_2/velocity_ecef geometry_msgs/TwistWithCovarianceStamped -> GNSS ECEF Velocity (0x92, 0x06)

• /gnss_2/odometry_earth nav_msgs/Odometry

  • pose -> GNSS ECEF Position (0x92, 0x04)

  • twist -> GNSS ECEF Velocity (0x92, 0x06)

• /gnss_2/time sensor_msgs/TimeReference -> GPS Timestamp (0x92, 0xD3)

• /ekf/imu/data sensor_msgs/Imu

  • orientation -> Attitude Quaternion (0x82, 0x03)

  • orientation_covariance -> Euler Angles Uncertainty (0x82, 0x0A)

  • angular_velocity -> Compensated Angular Rate (0x82, 0x0E)

  • linear_acceleration -> Compensated Acceleration (0x82, 0x1C)

• /ekf/llh_position sensor_msgs/NavSatFix

  • status -> GNSS Position Aiding Status (0x82, 0x43)

  • latitude -> LLH Position (0x82, 0x01)

  • longitude -> LLH Position (0x82, 0x01)

  • altitude -> LLH Position (0x82, 0x01)

  • position_covariance -> LLH Position Uncertainty (0x82, 0x08)

• /ekf/velocity geometry_msgs/TwistWithCovarianceStamped

  • twist.covariance -> NED Velocity Uncertainty (0x82, 0x09)

  • twist.twist.linear -> NED Velocity (0x82, 0x02)

  • twist.twist.angular -> Comp Angular Rate (0x82, 0x0E)

• /ekf/velocity_ecef geometry_msgs/TwistWithCovarianceStamped

  • twist.covariance -> ECEF Velocity Unvertainty (0x82, 0x37)

  • twist.twist.linear -> ECEF Velocity (0x82, 0x41)

  • twist.twist.angular -> Comp Angular Rate (0x82, 0x0E)

• /ekf/odometry_earth nav_msgs/Odometry

  • pose.covariance -> ECEF Position Uncertainty (0x82, 0x36) and Euler Angles Uncertainty (0x82, 0x0A)

  • pose.pose.position -> ECEF Position (0x82, 0x40)

  • pose.pose.orientation -> Attitude Quaternion (0x82, 0x03)

  • twist.covariance -> ECEF Velocity Unvertainty (0x82, 0x37)

  • twist.twist.linear -> ECEF Velocity (0x82, 0x41)

  • twist.twist.angular -> Comp Angular Rate (0x82, 0x0E)

• /ekf/odometry_map nav_msgs/Odometry

  • pose.covariance -> LLH Position Uncertainty (0x82, 0x08) and Euler Angles Uncertainty (0x82, 0x0A)

  • pose.pose.position -> ECEF Position (0x82, 0x40)

    • The ECEF position is converted to a local position relative to the relative position configuration before populating this message

  • pose.pose.orientation -> Attitude Quaternion (0x82, 0x03)

  • twist.covariance -> NED Velocity Uncertainty (0x82, 0x09)

  • twist.twist.linear -> NED Velocity (0x82, 0x02)

  • twist.twist.angular -> Comp Angular Rate (0x82, 0x0E)

• /ekf/dual_antenna_heading -> geometry_msgs/PoseWithCovarianceStamped

  • pose.pose.orientation -> GNSS Dual Antenna Status (0x82, 0x49)

    • Only the rotation about the Z axis will be populated in the orientation.

MIP Messages

The following topics contain messages that are exact copies of their MIP counterparts. The topic format is /mip/<descriptor_set_name>/<field_descriptor_name>. For more information on what descriptor_set_name and field_descriptor_name mean, see the MIP Protocol page.

See the message definitions for links to their MIP fields as well as field documentation

• /mip/sensor/temperature_statistics microstrain_inertial_msgs/MipSensorTemperatureStatistics

• /mip/sensor/overrange_status microstrain_inertial_msgs/MipSensorOverrangeStatus

• /mip/gnss_1/fix_info microstrain_inertial_msgs/MipGnssFixInfo

• /mip/gnss_1/sbas_info microstrain_inertial_msgs/MipGnssSbasInfo

• /mip/gnss_1/rf_error_detection microstrain_inertial_msgs/MipGnssRfErrorDetection

• /mip/gnss_2/fix_info microstrain_inertial_msgs/MipGnssFixInfo

• /mip/gnss_2/sbas_info microstrain_inertial_msgs/MipGnssSbasInfo

• /mip/gnss_2/rf_error_detection microstrain_inertial_msgs/MipGnssRfErrorDetection

• /mip/gnss_corrections/rtk_corrections_status microstrain_inertial_msgs/MipGnssCorrectionsRtkCorrectionsStatus

• /mip/ekf/status microstrain_inertial_msgs/MipFilterStatus

• /mip/ekf/gnss_position_aiding_status microstrain_inertial_msgs/MipFilterGnssPositionAidingStatus

• /mip/ekf/multi_antenna_offset_correction microstrain_inertial_msgs/MipFilterMultiAntennaOffsetCorrection

• /mip/ekf/gnss_dual_antenna_status microstrain_inertial_msgs/MipFilterGnssDualAntennaStatus

• /mip/ekf/aiding_measurement_summary microstrain_inertial_msgs/MipFilterAidingMeasurementSummary

• /mip/system/built_in_test microstrain_inertial_msgs/MipSystemBuiltInTest

Other Messages

The following topics do not fall into any of the above categories and are likely addons to the device not specifically from the MIP protocol

• /ekf/status microstrain_inertial_msgs/HumanReadableStatus

  • Human readable status of the device. This message will contain strings that should be easily readable, but SHOULD NOT be used in a production application

• /nmea nmea_msgs/Sentence

  • GGA NMEA sentences may be published from the aux port of a GQ7 if it is connected and the following configuration is set:

       aux_port: '/dev/ttyACM1'  # The serial port that the aux port is connected on
       ntrip_interface_enable: True  # Enable the sending of NMEA messages

  • Several types of NMEA sentences may be published from the main port of the GQ7 if this section of config is configured to stream NMEA.

Subscriptions

The following topics are subscribed to by the node. Most are controlled by individual booleans in the configuration and need to be enabled in order to be subscribed to

• /rtcm rtcm_msgs/Message

  • Will be enabled if ntrip_interface_enable is true and the device is a GQ7. Will subscribe to RTCM in order to pass to the aux port of the GQ7

• /ext/time sensor_msgs/TimeReference

  • Will be enabled if subscribe_ext_time is true and the device supports external GPS time updates. Will subscribe to external time updates and send them to the device.

  • NOTE: The time update command should be done once a second within the top 250 milliseconds of the second.

• /ext/llh_position sensor_msgs/NavSatFix

  • Will be enabled if subscribe_ext_fix is true and the device supports the LLH position aiding command. Will subscribe to external LLH position and send it to the device.

• /ext/velocity_ned geometry_msgs/TwistWithCovarianceStamped

  • Will be enabled if subscribe_ext_vel_ned is true and the device supports the NED velocity aiding command. Will subscribe to external NED velocity and send it to the device.

• /ext/velocity_enu geometry_msgs/TwistWithCovarianceStamped

  • Will be enabled if subscribe_ext_vel_enu is true and the device supports the NED velocity aiding command. Will subscribe to external ENU velocity and send it to the device.

• /ext/velocity_ecef geometry_msgs/TwistWithCovarianceStamped

  • Will be enabled if subscribe_ext_vel_ecef is true and the device supports the ECEF velocity aiding command. Will subscribe to external ECEF velocity and send it to the device.

• /ext/velocity_body geometry_msgs/TwistWithCovarianceStamped

  • Will be enabled if subscribe_ext_vel_body is true and the device supports the body velocity aiding command. Will subscribe to external body velocity and send it to the device.

• /ext/heading_ned geometry_msgs/PoseWithCovarianceStamped

  • Will be enabled if subscribe_ext_heading_ned is true and the device supports the true heading aiding command. Will subscribe to external heading in the NED frame and send it to the device.

• /ext/heading_enu geometry_msgs/PoseWithCovarianceStamped

  • Will be enabled if subscribe_ext_heading_enu is true and the device supports the true heading aiding command. Will subscribe to external heading in the ENU frame and send it to the device.

• /ext/mag sensor_msgs/MagneticField

  • Will be enabled if subscribe_ext_mag is true and the device supports the magnetic field aiding command. Will subscribe to external magnetic field data and send it to the device.

• /ext/pressure sensor_msgs/FluidPressure

  • Will be enabled if subscribe_ext_pressure is true and the device supports the pressure aiding command. Will subscribe to external pressure data and send it to the device.

Services

The following services are available on this node. All services that your device supports will be created when the node is activated.

• /raw_file_config/main/read microstrain_inertial_msgs/RawFileConfigRead

• /raw_file_config/main/write microstrain_inertial_msgs/RawFileConfigWrite

• /raw_file_config/aux/read microstrain_inertial_msgs/RawFileConfigRead

• /raw_file_config/aux/write microstrain_inertial_msgs/RawFileConfigWrite

• /mip/base/get_device_information microstrain_inertial_msgs/MipBaseGetDeviceInformation

• /mip/three_dm/capture_gyro_bias microstrain_inertial_msgs/Mip3dmCaptureGyroBias

• /mip/three_dm/device_settings/save std_srvs/Empty

• /mip/three_dm/device_settings/load std_srvs/Empty

• /mip/three_dm/gpio_state/read microstrain_inertial_msgs/Mip3dmGpioStateRead

• /mip/three_dm/gpio_state/write microstrain_inertial_msgs/Mip3dmGpioStateWrite

• /mip/ekf/reset std_srvs/Empty

More Resources

Getting Started with GQ7

Getting Started with GQ7

Transforms and Frame IDs

The driver now supports publishing several different transforms. See Transforms for more information on the transforms and frame IDs used.

Relative Position Configuration

All devices with global postiion capabilities can now publish relative position. See Relative Position Configuration for more detailed information.

Frames and use_enu_frame

The use_enu_frame parameter considerably changes the behavior of this application. See use_enu_frame for more information.

Examples

See Examples for more information.