imu_utils

A ROS package tool to analyze the IMU performance. C++ version of Allan Variance Tool. The figures are drawn by Matlab, in scripts.

Actually, just analyze the Allan Variance for the IMU data. Collect the data while the IMU is Stationary, with a two hours duration.

Dependencies

1. Ceres

# CMake
sudo apt-get install cmake
# google-glog + gflags
sudo apt-get install libgoogle-glog-dev libgflags-dev
# BLAS & LAPACK
sudo apt-get install libatlas-base-dev
# Eigen3
sudo apt-get install libeigen3-dev
# SuiteSparse and CXSparse (optional)
sudo apt-get install libsuitesparse-dev
# Ceres
git clone https://github.com/ceres-solver/ceres-solver.git
cd ceres-solver && mkdir build && cd build && cmake .. && make -j32
sudo make install

2. libdw

sudo apt-get install libdw-dev

T265 imu calibration

1. T265

Get realsense-ros

Change rs_t265.launch:

<arg name="unite_imu_method" default="linear_interpolation"/>

And then:

roslaunch realsense2_camera rs_t265.launch

2. Imu utils

source /opt/ros/noetic/setup.bash && catkin build
source /opt/ros/noetic/setup.bash && catkin build && source devel/setup.bash && roslaunch realsense2_camera rs_t265.launch

Result

---

Raw

refrence

Refrence technical report: Allan Variance: Noise Analysis for Gyroscopes, vectornav gyroscope and An introduction to inertial navigation.

Woodman, O.J., 2007. An introduction to inertial navigation (No. UCAM-CL-TR-696). University of Cambridge, Computer Laboratory.

Refrence Matlab code: GyroAllan

IMU Noise Values

Parameter	YAML element	Symbol	Units
Gyroscope "white noise"	gyr_n
Accelerometer "white noise"	acc_n
Gyroscope "bias Instability"	gyr_w
Accelerometer "bias Instability"	acc_w

• White noise is at tau=1;

• Bias Instability is around the minimum;

(according to technical report: Allan Variance: Noise Analysis for Gyroscopes)

sample test

• blue : Vi-Sensor, ADIS16448, 200Hz
• red : 3dm-Gx4, 500Hz
• green : DJI-A3, 400Hz
• black : DJI-N3, 400Hz
• circle : xsens-MTI-100, 100Hz

How to build and run?

to build

sudo apt-get install libdw-dev

• download required code_utils;

• put the ROS package imu_utils and code_utils into your workspace, usually named catkin_ws;

• cd to your workspace, build with catkin_make;

to run

• collect the data while the IMU is Stationary, with a two hours duration;

• (or) play rosbag dataset;

 rosbag play -r 200 imu_A3.bag

• roslaunch the rosnode;

roslaunch imu_utils A3.launch

Be careful of your roslaunch file:

<launch>
    <node pkg="imu_utils" type="imu_an" name="imu_an" output="screen">
        <param name="imu_topic" type="string" value= "/djiros/imu"/>
        <param name="imu_name" type="string" value= "A3"/>
        <param name="data_save_path" type="string" value= "$(find imu_utils)/data/"/>
        <param name="max_time_min" type="int" value= "120"/>
        <param name="max_cluster" type="int" value= "100"/>
    </node>
</launch>

sample output:

type: IMU
name: A3
Gyr:
   unit: " rad/s"
   avg-axis:
      gyr_n: 1.0351286977809465e-04
      gyr_w: 2.9438676109223402e-05
   x-axis:
      gyr_n: 1.0312669892959053e-04
      gyr_w: 3.3765827874234673e-05
   y-axis:
      gyr_n: 1.0787155789128671e-04
      gyr_w: 3.1970693666470835e-05
   z-axis:
      gyr_n: 9.9540352513406743e-05
      gyr_w: 2.2579506786964707e-05
Acc:
   unit: " m/s^2"
   avg-axis:
      acc_n: 1.3985049290745563e-03
      acc_w: 6.3249251509920116e-04
   x-axis:
      acc_n: 1.1687799474421937e-03
      acc_w: 5.3044554054317266e-04
   y-axis:
      acc_n: 1.2050535351630543e-03
      acc_w: 6.0281218607825414e-04
   z-axis:
      acc_n: 1.8216813046184213e-03
      acc_w: 7.6421981867617645e-04

dataset

DJI A3: 400Hz

Download link: 百度网盘

DJI A3: 400Hz

Download link: 百度网盘

ADIS16448: 200Hz

Download link:百度网盘

3dM-GX4: 500Hz

Download link:百度网盘

xsens-MTI-100: 100Hz

Download link:百度网盘