IHMC ROS Control Support

Provides a bridge between Java and ROS Control. The simple interface, ihmc_ros_control::IHMCRosControlJavaBridge and the similarly named Java interface, provides a way to write controllers that operate on the resources exposed by ros_control’s hardware_interface::EffortJointInterface. ihmc_ros_control::IHMCWholeRobotControlJavaBridge is an extension of the base interface and allows for implementing a ros_control controller that hooks in to the initRequest method to acquire resources of multiple types in a single ROS plugin. Currently, you can use this interface to write controllers that work with all of the following simultaneously:

• hardware_interface::JointStateInterface
• hardware_interface::EffortJointInterface
• hardware_interface::PositionJointInterface
• hardware_interface::ImuSensorInterface
• hardware_interface::ForceTorqueSensorInterface

Installation

ihmc_ros_control is a Catkin package. We currently support ROS Indigo on Ubuntu 14.04 LTS with release 0.5.0 and ROS Kinetic on Ubuntu 16.04 LTS with release 0.6.0. We plan to continue targeting LTS releases of both ROS and Ubuntu.

We use some C++11 features in ihmc_ros_control. The versions of gcc and clang available in Ubuntu 14.04 should be fine, and we have modified our CMakeLists.txt accordingly to set up the C++11 features correctly. You will also need a Java JDK (not JRE), as you will need the Java Native Interface headers to compile the C++ code. We support OpenJDK 8 and Oracle JDK 8.

On Ubuntu 16.04:

$ sudo apt-get update
$ sudo apt-get install openjdk-8-jdk

Ubuntu 14.04 may require tapping a PPA: https://launchpad.net/~openjdk-r/+archive/ubuntu/ppa

To install ihmc-ros-control, simply clone the repository in to a catkin workspace and then catkin_make install or catkin build && catkin install if using catkin_tools. If you have an existing catkin workspace, we recommend “overlaying” any IHMC code on top of your code in its own workspace, e.g. ihmc_catkin_ws. If you don’t currently have any IHMC code, that might look something like:

$ cd ~
$ mkdir -p ihmc_catkin_ws/src
$ cd ihmc_catkin_ws
$ catkin_init_workspace src
$ cd src
$ # use https://github.com/ihmcrobotics/ihmc-ros-control.git if you don't have ssh keys configured on GitHub
$ git clone git@github.com:ihmcrobotics/ihmc-ros-control.git
$ cd ..
$ catkin_make install

You may also be interested in ihmc_workspaces which provides ways to get at other IHMC ROS packages.

CMake JNI Errors

If CMake has problems finding the JNI packages or if there are Java/JNI related compilation problems during catkin_make, export JAVA_HOME before running catkin_make:

$ export JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64/

Writing controllers (Java)

IHMCRosControl is provided as a Maven artifact on Bintray: https://bintray.com/ihmcrobotics/maven-release/IHMCRosControl. You can find instructions for depending on our Maven artifacts at Bintray.

As a quick example, to use IHMCRosControl in a Gradle project:

• Add the following repository to your buildscript:

repositories {
    maven {
        url  "http://dl.bintray.com/ihmcrobotics/maven-release"
    }
}

• Add the following dependency to your gradle dependencies:

compile group: 'us.ihmc', name: 'IHMCRosControl', version: '0.6.0'

Then implement either “IHMCRosControlJavaBridge” or “IHMCWholeRobotControlJavaBridge”, depending on which hardware interfaces you would like to control.

Examples

This package provides an example launch file for controlling the RRBot Gazebo demo via the simple EffortJointInterface adapter. For more complex examples, including an example of the Whole Robot interface, take a look at the Valkyrie project in IHMC Open Robotics Software along with the ihmc_valkyrie_ros ROS package for launch files.