Inertial Labs ROS Driver Package

Posted by Will Dillingham on Aug 19, 2020 1:49:18 PM

Inertial Labs logo - new2-1

 

Purpose: To describe the Inertial Labs ROS Driver Package for INS/MRU/AHRS/IMU.

Last Updated: December 8, 2020

INS

Click Here to Download ROS Package for Inertial Labs Products

The InertialLabs_ros_package package is a linux ROS driver for GPS-Aided Inertial Navigation Systems (INS), IMU-P, AHRS and AHRS-10 of Inertial Labs. The package is developed based on the official SDK v0.2 for Linux. 

The package is tested on Ubuntu 16.04 LTS & 18.04 LTS with ROS Kinetic & ROS Melodic . You can install ROS from here.

License

  • The license for the official SDK is the MIT license which is included in the ins_ros/inertiallabs_sdk
  • The license for the other codes is Apache 2.0 whenever not specified

Compiling

This is a Catkin package. Make sure the package is on ROS_PACKAGE_PATH after cloning the package to your workspace. And the normal procedure for compiling a catkin package will work.

$ cd <your_work_space>/src
$ $ git clone https://us.inertiallabs.com:31443/scm/ins/inertiallabs-ros-pkgs.git
$ cd <your_work_space>
$ catkin_make_isolated
$ source devel_isolated/setup.bash

Why catkin_make_isolated ?

We developed a package for multiple devices with same dependencies, so to avoid confilcts we are compiling using catkin_make_isolated. If you need to use ins only, you get the subpackages like inertiallabs_ins, inertiallabs_sdk, intertiallabs_msgs and intertiallabs_ros_pkgs to your workspace and use your own build system to compile it. You have to change the intertiallabs_ros_pkgs/intertiallabs_ros_pkgs/package.xml

<exec_depend>inertiallabs_ins</exec_depend>

Node

Example rosnodes:

For ins OPVT2AHR packet via USB serial port:

rosrun inertiallabs_ins il_ins url:=serial:/dev/ttyUSB0:460800 _ins_output_format:=0x58

For ins OPVT packet via UDP (INS hostname is used):

rosrun inertiallabs_ins il_ins _ins_url:=udp:INS-F2001234:23 _ins_output_format:=0x52

For ins OPVT packet via UDP (INS IP address is used):

rosrun inertiallabs_ins il_ins _ins_url:=udp:192.168.0.249:23 _ins_output_format:=0x52

Example Usage

Parameters

url (string, default: serial:/dev/ttyUSB0:115200)

Port the device is connected to. Can be serial:[path to device]:[baudrate], tcp:[hostname or address]:[tcp server port], or udp:[hostname or address]:[udp server port]. Inertial Labs Driver supports serial connection

ins_output_format (int, 82)

The output data format of the INS data according to IL INS ICD.

IL_SENSOR_DATA 0x50
IL_OPVT 0x52
IL_MINIMAL_DATA 0x53
IL_QPVT 0x56
IL_OPVT2A 0x57
IL_OPVT2AHR 0x58
IL_OPVT2AW 0x59
IL_OPVTAD 0x61
MRU_OPVTHSSHR 0x64
IL_OPVT_RAWIMU_DATA 0x66
IL_OPVT_GNSSEXT_DATA 0x67
IL_USER_DEFINED_DATA 0x95

Published Topics - feel free to modify using fields from IL::INSDataStruct

/Inertial_Labs/sensor_data (ins_ros/sensor_data)

Publish Gyro(x,y,z) , Acceleration(x,y,z), Magnetic (x,y,z), Temperature, Input Voltage, Pressure, Barometric height.

/Inertial_Labs/ins_data (ins_ros/ins_data)

Publish GPS INS Time, GPS IMU Time, Millisecond of the week, Latitude, Longitude, Altitude, Heading, Pitch , Roll, Orientation quaternion, East Velocity, North Velocity, Up Velocity values, Solution status, Position STD, Heading STD, Unit Status.

/Inertial_Labs/gps_data (ins_ros/gps_data)

Publish Latitude, Longitude, Altitude, Ground Speed, Track Direction, Vertical Speed values.

/Inertial_Labs/gnss_data (ins_ros/gnss_data)

Publish GNSS service Info 1, Info 2, Satellites Used, Velocity Latency, Heading status, Heading, Pitch, GDOP, PDOP, HDOP, VDOP, TDOP, New GNSS Flag, Age of differential correction.

/Inertial_Labs/marine_data (ins_ros/marine_data)

Publish Heave, Surge, Sway, Heave Velocity, Surge Velocity, Sway Velocity, Significant Wave Height.

FAQ

1. The driver can't open my device?
Make sure you have ownership of the device in /dev.

2. Why do I have a permission error during the initialization process of the driver?
Most often, this is because the baud rate you set does not match the package size to be received. Try increasing the baud rate.

3. Why is the IMU data output rate much lower than what is set?
This may be due to a recent change in the FTDI USB-Serial driver in the Linux kernel, the following shell script might help:

# Reduce latency in the FTDI serial-USB kernel driver to 1ms
# This is required due to https://github.com/torvalds/linux/commit/c6dce262
for file in $(ls /sys/bus/usb-serial/devices/); do
     value=`cat /sys/bus/usb-serial/devices/$file/latency_timer`
     if [ $value -gt 1 ]; then
          echo "Setting low_latency mode for $file"
          sudo sh -c "echo 1 > /sys/bus/usb-serial/devices/$file/latency_timer"
    fi
done

4. Why is a field value always zero?

This is most likely because this field is not provided in the selected INS data packet. The most versatile data packet is User-Defined Data which allows to order any set of fields.

Bug Report

To report any bugs, you can send an e-mail to support@inertiallabs.com.

Topics: MRU, AHRS, IMU, INS, ROS, Driver


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