R1 model generator

This repository contains the resources and scripts to generate the models and the workspaces for Rviz, MoveIt, Gazebo and iKin. The models (URDF, SDF and DH parameters) are generated using a custom python script and copied inside of the proper folders.

Table of Contents

• Dependencies
• Using the models
• Updating the models
• Adding the checkerboard

Dependencies

The following dependencies are required to use the models:

• YARP
• gazebo-yarp-plugins
• Gazebo
• RViz
• MoveIt
• iKin

The following dependencies are required to generate and update the models:

• Python
• Gazebo
• simmechanics-to-urdf
• iDynTree

Using the models

Gazebo

Install YARP, gazebo, and gazebo_yarp_plugins

Add CER models to the GAZEBO_MODEL_PATH:

export GAZEBO_MODEL_PATH=<cer-sim>/gazebo

Start YARP server

yarp server

Start gazebo

gazebo

Drag the CER model into the scene.

RViz

Init and build the catkin workspace:

cd <cer-sim>/catkin_ws/src
catkin_init_workspace
cd <cer-sim>/catkin_ws
catkin_make

Add to .bashrc

if [ -f <cer-sim>/catkin_ws/devel/setup.bash ]; then
  . <cer-sim>/catkin_ws/devel/setup.bash
fi

Start roscore:

roscore

Start yarp server:

yarp server --ros

Start rviz and robot-state-publisher:

roslaunch cer_rviz cer.launch

geomagic-marker

Build:

cd <cer-sim>/src/geomagic-marker
mkdir build
cd build
ccmake ..
make

Start the module

<cer-sim>/src/geomagic-marker/build/geomagic-marker

Updating the models

The proper procedure to update the models is to modify the files inside of the resources folder. Subsequently, run the python script generate_models.py.

Any local change to the models files will be lost.

Adding the checkerboard

The checkerboard is a board with a pattern of white and black squares ("chequered pattern"). The geometry file (*.dae) in the mesh folder represents a rectangular checkerboard with a 7 by 9 pattern. To add the checkerboard to the R1 model simply add the following code to the *.sdf file in the gazebo folder. Since in normal conditions the checkerboard is not necessary, the modified sdf model shouldn't be committed and changes are lost every time the model is regenerated

    <link name='checkerboard_link'>
      <pose frame=''>VALUE_1 0.0 VALUE_2 1.570795 0.0 3.14159</pose>
      <visual name='checkerboard_link_visual'>
        <pose frame=''>0 0 0 0 0 0</pose>
        <geometry>
          <mesh>
            <scale>0.001 0.001 0.001</scale>
            <uri>model://cer/meshes/dae/checkerboard.dae</uri>
          </mesh>
        </geometry>
      </visual>
    </link>
    <joint name='checkerboard_joint' type='fixed'>
      <child>checkerboard_link</child>
      <parent>mobile_base_body_link</parent>
    </joint>

Where we have:

VALUE_1 = B + 0.1779

VALUE_2 = A + 0.2585

As shown in Figure 1, A is the distance between the terrain and the lower border of the white and black squares. While B represents the distance between the black and white squares front surfaces and the border of the covers of R1. The border of the covers can be easily accessed by extending the torso joint of the robot.