Issues to get the camera_calibration running

[Felix2M]

Since I head lots of issues to get this plugin running with Ubuntu 20.04 I created a ReadMe file how I was able to compile and run it. I would appreciate if someone could provide some help to set it up easier or add some steps to the official ReadMe file.

Additionally I had some issues with a distirbuted ROS Systems. The calibration software takes the sample immediatly after the robot reaches the position, but sometimes my TF was not up to date already, so I added a delay to solve this problem with:

bool ControlTabWidget::takeTransformSamples()
{
  // Store the pair of two tf transforms and calculate camera_robot pose
  sleep(1.5);

This was already mentioned in #103, but I think there are better solutions to this.

Also my re-projectionerror was quite high. I got for translation an error of 0.3 m, which would be a lot. When I tested the system with this high error it was able grasp with an accuracy of 3 mm. Is this a unit problem or does this only occur in my case?

Here the ReadMe file:

Moveit Calibration

Install Package to calibrate the camera position

git clone https://github.com/ros-planning/moveit_calibration
cd ..
rosdep install --from-paths src --ignore-src -r -y
catkin_make

Install dependencies

Install the dependencies in your catkin workspace.

Handeye is needed otherwise the error "Failed to load python module: handeye.calibrator" occurs when taking calibration samples (see last step). Install it:

git clone https://github.com/crigroup/handeye.git
rosdep install --from-paths . --ignore-src -r -y
cd ..
catkin_make

The handeye package is depending on baldor. Install it:

git clone https://github.com/crigroup/baldor.git
rosdep install --from-paths . --ignore-src -r -y
cd ..
catkin_make

Check your version normal is 0.3.8 but we need >=0.3.9
To install follow the following steps of #109 (comment) to install

pkg-config --modversion openblas

Remove existing openblas. Do this with caution and maybe backup your machine first!!
sudo apt -y remove libopenblas*

download openblas from official github page

cd ~
wget https://github.com/xianyi/OpenBLAS/releases/download/v0.3.23/OpenBLAS-0.3.23.tar.gz
tar xf OpenBLAS-0.3.23.tar.gz 
cd OpenBLAS-0.3.23/
make
make install

cd ~/Downloads
unzip "OpenBLAS 0.3.9 version.zip" -d /opt
cd /opt
sudo mv xianyi-OpenBLAS-33f76a6 "OpenBLAS-0.3.9"
cd OpenBLAS-0.3.9/
sudo make FC=gfortran
sudo make install
export PKG_CONFIG_PATH=/opt/OpenBLAS/lib/pkgconfig:$PKG_CONFIG_PATH
pkg-config --modversion openblas

Create a symbolic link to the lib folder:

sudo ln -s /home/faps/OpenBLAS-0.3.23/libopenblas.so /usr/lib/x86_64-linux-gnu/libopenblas.so

Modifications for using saved joint_states.yaml

Change the handeye_control_widget.cpp, which is located at moveit_calibration/moveit_calibration_gui/handeye_calibration_rviz_plugin/src/handeye_control_widget.cpp

Add sleep to make sure the tf tree is updated before taking a sample:

bool ControlTabWidget::takeTransformSamples()
{
  // Store the pair of two tf transforms and calculate camera_robot pose
  sleep(1.5);

Change robot velocity:

move_group_->setMaxVelocityScalingFactor(0.5); ==> move_group_->setMaxVelocityScalingFactor(0.1);
move_group_->setMaxAccelerationScalingFactor(0.5); ==> move_group_->setMaxAccelerationScalingFactor(0.1);

and build the workspace afterwards with catkin_make

Start Calibration Setup

start a new terminal with the following commands:

export LC_NUMERIC=en_US.UTF-8
rviz