REACH

Robotic Evaluation And Comparison Heuristic

Description

The REACH repository is a tool that allows users to visualize and quantitatively evaluate the reach capability of a robot system for a given workpiece.

The package is comprised of several packages:

• reach_msgs
  • Message definitions for the reach study
• reach_core
  • Core code to operate the reach study
  • Interfaces for plugins
    • Inverse kinematics solver
    • Robot pose evaluator
    • Reach Display
• moveit_reach_plugins
  • Implementations of the plugin interfaces built on the MoveIt! planning framework

Installation

cd ~/catkin_ws/src
git clone https://github.com/ros-industrial/reach.git
cd ..
rosdep install --from-paths src --ignore-src -r -y
catkin build

Demo

A simple demonstration of the capability of this repository is provided in the reach_demo package. See the instructions for details on how to run the demo.

Usage

1. Create a URDF of your robot system
2. Create a launch file to load the URDF, SRDF, and other required parameters (e.g. related to kinematics, joint, limits) to the parameter server
3. Create a mesh model of the workpiece
4. Create a point cloud of the target points on the workpiece
   • This point cloud can be generated using a command line tool from PCL 1.8:

     pcl_mesh_sampling <workpiece_mesh>.ply <output_cloud>.pcd -n_samples <number of samples> -leaf_size <leaf_size> -write_normals true
     

5. Create a configuration YAML file (see example in config directory)
6. Run the setup launch file

   roslaunch reach_core setup.launch robot:=<load_robot_parameters>.launch
   

7. Run the reach study analysis

   roslaunch reach_core start.launch config_file:=<config_file.yaml> config_name:=<arbitrary_config>
   

The algorithm searches for alignment of the TCP Z-axis with the pointcloud normals.

Hints

1. Ensure the object mesh scale and the point cloud scale match and are correct in RViz. It is common to be off by a factor of 1000.
2. If it is OK for a robot link to collide with the mesh, add the link to "touch_links" fields in the config file.
3. A different IK solver may yield better results than the default. A good choice is TracIK. Typically this is configured in kinematics.yaml.
4. reach_core has some options for programmatically querying the reachability database.