NimbRo Primitive Fitter

This package fits primitive shapes (capsules and boxes) to complex meshes to reduce computational complexity in simulations and planning tasks.

Installation

Prerequisites:

sudo apt install libtool libltdl-dev gfortran liblog4cxx-dev coinor-libipopt-dev libpugixml-dev

The roboptim packages:

Clone:

git clone --recursive https://github.com/roboptim/roboptim-core.git
git clone --recursive https://github.com/roboptim/roboptim-core-plugin-ipopt.git
git clone --recursive https://github.com/roboptim/roboptim-capsule.git

Build and install:

Follow this order: roboptim-core > roboptim-core-plugin-ipopt > roboptim-capsule (More detailed instructions can be found within the roboptim-core module)

Navigate to respective projects and:

mkdir build          # (1) Create a build directory
cd build             # (2) Go to the newly created build directory
cmake [options] ..   # (3) Generate the build files

make                 # (4) Compile the package
make install         # (5) Install the package into the prefix 

Change the CMAKE_INSTALL_PREFIX env variable if you want the installation to be in a non-standard location (for example, if you don't have sudo privileges).

If using non-standard location be sure to execute immediately after installing roboptim-core:

export PKG_CONFIG_PATH=$PKG_CONFIG_PATH:<CMAKE_INSTALL_PREFIX>/lib/pkgconfig/

For your convinience, you might want to add this to your ~/.bashrc.

How to use?

Example

This package comes with examples which fits capsules or boxes to the links of an UR10 robotic arm and the NimbRo-Op2X robot. You will need the ur_description or the nimbro_op_model(https://github.com/AIS-Bonn/humanoid_op_ros/tree/master/src/nimbro/hardware/nimbro_op_model) ROS packages to execute the launch files. Once you have this packages, you can try for example:

roslaunch nimbro_primitive_fitter capsule_ur10.launch

or

roslaunch nimbro_primitive_fitter box_op2x.launch

The launch-file specifies the URDF description and generates a new file with the corresponding primitives. To make this pkg work with your model, simply change the corresponding ros parameters in the launch file. The box-fitting comes with a number of parameters, which might be required to change for specific meshes. If required, you can find the description of those parameters in the ApproxMVBB Documentation.

Contributing

How to add new primitive shapes

Create a class that inherits from ShapeFit, thus you need to define the functions writeUrdf and writeUrdfXacro. These functions are supposed to write the fitted shape to the URDF XML. Additionally, you will need to define a static addMacroXacro method, which writes the Xacro Macro that is neccessary in writeUrdfXacro. Finally, the addMacroXacro needs to be included in the Urdf::addXacroDef function. For a simple non-macro example, refer to BoxFit, for help on using macros, refer to the CapsuleFit class.

How to add support for different mesh-files

Firstly, a class inheriting from Meshfile needs to be created, thus including a getPoints and getTransformationMatrix function. The former returns the points of the mesh in form of a flat vector of coordinates like (x1, y1, z1, x2, y2, z2,...). The latter returns the intrinsic transformation of the mesh, like it is neccessary e.g. for collada files. Finally, the file has to be integrated to the VersatileFitter::fit function, solely to check for file extensions.