FLVIS

The implementation of Feedforward-feedback Loop-based Visual Inertial System.

1-Video

<img src="http://img.youtube.com/vi/ljZWb2x6CRQ/0.jpg" alt="cla" width="480" height="300" border="1" />

EuRoC DataSet MH_05	Handheld Test in Lab	FlVIS on UAV Platform

2-Relevent Publication:

Stereo Visual Inertial Pose Estimation Based on Feedforward and Feedbacks

3-Support Hardware/Dataset:

Intel RealSense D435i Camera
EuRoC MAV Dataset

4-Build The Project

If you do not want to do a lotta prequisite setting, you can use Docker.

Else...Do the following in (Ubuntu 16.04 + ROS Kinetic; Ubuntu 18.04 + ROS melodic; Ubuntu 20.04 + ROS noetic):

A. Prerequisites

Make sure your realsense SDK and Wrapper are all good RS_SDK & RS_ROS.

B. Compile

Clone the repository to the catkin work space eg. /catkin_ws/src

  git clone https://github.com/HKPolyU-UAV/FLVIS.git

Install 3rd Part library

  cd catkin_ws/src/FLVIS/3rdPartLib/
  ./install3rdPartLib.sh

Compile

  cd ~/catkin_ws
  catkin_make

C. Others

If you want to use FLVIS with GPU acceleration, try this repo.

5-Verification

Support Platform D435i(Depth/Stereo Mode), EuRoC Dataset, KITTI Dataset

5.1 D435i Camera Depth Mode

5.1.1 Use our recorded rosbag

Download the dataset Link-melab_sn943222072828.bag to /bag folder
Decompress the rosbag:

rosbag decompress melab_sn943222072828.bag

run the following launch files:

roslaunch flvis rviz_bag.launch
roslaunch flvis flvis_bag.launch

5.1.2 Use your own camera:

Install the realsense driver and its ros wrapper
Boot the d435i camera and echo the camera infomation

roslaunch flvis d435i_depth.launch
rostopic echo /camera/infra1/camera_info

You will get the camera infomation like:

As shown, where the resolution is 640x480 and fx=384.16455078125; fy=384.16455078125; cx=320.2144470214844;cy=238.94403076171875.
Edit these information in the config yaml file (say: /launch/d435i/sn943222072828_depth.yaml):

image_width: 640
image_height: 480
cam0_intrinsics: [384.16455078125, 384.16455078125, 320.2144470214844, 238.94403076171875]#fx fy cx cy
cam0_distortion_coeffs: [0.0, 0.0, 0.0, 0.0]#k1 k2 r1 r2

In the launch file flvis_d435i.launch, make sure /yamlconfigfile is point to the edited config file

<param name="/yamlconfigfile" type="string" value="$(find flvis)/launch/d435i/sn943222072828_depth.yaml"/>

run the following launch files:

roslaunch flvis rviz_bag.launch
roslaunch flvis flvis_d435i_depth.launch

5.2 D435i Camera Stero Mode

Like what we did in 5.1.2, we need to config the sn943222072828_stereo.yaml
Note that, by default the two camera share the same intrinsic parameters, and the baseline length is 0.05m:

cam0_intrinsics: [384.16455078125, 384.16455078125, 320.2144470214844, 238.94403076171875]#fx fy cx cy
cam0_distortion_coeffs: [0.0, 0.0, 0.0, 0.0]#k1 k2 r1 r2
cam1_intrinsics: [384.16455078125, 384.16455078125, 320.2144470214844, 238.94403076171875]#fx fy cx cy
cam1_distortion_coeffs: [0.0, 0.0, 0.0, 0.0]#k1 k2 r1 r2
T_cam0_cam1:
[ 1.0,  0.0,  0.0,  0.05,
  0.0,  1.0,  0.0,  0.0,
  0.0,  0.0,  1.0,  0.0,
  0.0,  0.0,  0.0,  1.0]

5.3 D435i Camera Depth/Stereo + Pixhawk IMU Mode

We also support fusing any Inertial Measurement Unit (IMU), and stereo camera or depth camera. For example, a very common application is running VIO on quadrotors to estimate its own pose by IMU readings from Pixhawk. We need to config the catkin_ws/FLVIS/launch/d435_pixhawk/sn841512070537_depth_px4.yaml or catkin_ws/FLVIS/launch/d435_pixhawk/sn943222072828_stereo_px4.yaml
run the following launch files:

roslaunch flvis flvis_d435_pixhawk_depth.launch

or

roslaunch flvis flvis_d435_pixhawk_stereo.launch

Check your mavros status by:

rostopic echo /mavros/imu/data

If IMU response normally, then open a new terminal, and check by:

rostopic echo /mavros/local_position/pose

5.4 EuRoC MAV Dataset

Download the dataset(say MH_05_difficult) into the bag folder:

roscd flvis/bag/
wget http://robotics.ethz.ch/~asl-datasets/ijrr_euroc_mav_dataset/machine_hall/MH_05_difficult/MH_05_difficult.bag

Edit the corresponding bag name in flvis_euroc_mav.launch file:

<node pkg="rosbag" type="play" name="rosbag" args="$(find flvis)/bag/MH_05_difficult.bag"/>

run the following launch files:

roslaunch flvis rviz_euroc.launch
roslaunch flvis flvis_euroc_mav.launch

5.5 KITTI Dataset

Download the dataset into the bag folder:

Decompress poses.zip file and edit the corresponding bag name in flvis_kitti.launch file:

<param name="/publish_gt"             type="bool"    value="true" />
<param name="/dataset_folder_path"    type="string"  value="$(find flvis)/bag/KITTI/dataset/sequences/00/" />
<param name="/dataset_gt_file"        type="string"  value="$(find flvis)/bag/KITTI/dataset/poses/00.txt" />

run the following launch files:

roslaunch flvis rviz_kitti.launch
roslaunch flvis flvis_kitti.launch

If tracking failure or optimize failure happen, please try a lower dataset publish rate 10 or 15 instead:

<param name="/dataset_pub_rate"       type="int"     value="15" />

Maintainer:

Shengyang Chen(Dept.ME,PolyU): shengyang.chen@connect.polyu.hk
Yurong Feng(Dept.AAE,PolyU): yu-rong.feng@connect.polyu.hk
Yajing Zou(Dept.LSGI,PolyU):rick.zou@connect.polyu.hk