| Note: This tutorial assumes that you have completed the previous tutorials: ROS Tutorials, qb SoftHand, qbmove. |
 Please ask about problems and questions regarding this tutorial on answers.ros.org. Don't forget to include in your question the link to this page, the versions of your OS & ROS, and also add appropriate tags. |
Basics
Description: Basic knowledge on multi-device systemKeywords: qbrobotics SoftHand qbmove chain
Tutorial Level: BEGINNER
This repository contains just few examples of how to properly set up several qbrobotics® devices to work together on ROS related applications.
Please, refer first to the following wikis:
Installation
To install also this packages, simply clone https://bitbucket.org/qbrobotics/qbchain-ros.git in your Catkin Workspace as you have done for the others. Note that there is no need to recompile since this repository contains only example configurations based on the other packages.
Actually the installation is not required. Nonetheless it is recommended to follow the proposed approach for your customizations to keep everything tidy and structured.
Usage
Each system configuration has a unique name. And that name is used as prefix for all the configuration files:
qb_chain_description/rviz/<unique_name>.rviz: the rviz configuration file.
qb_chain_description/urdf/<unique_name>.urdf.xacro: the urdf/xacro model describing the physical chained system by connecting together simpler device modules (and possibly other parts).
qb_chain_control/launch/<unique_name>_control.launch: the launch file to start the control Node for the given chained system. Be aware that this must strictly match the above URDF model of your actual system, e.g. device types, joint names, ...
qb_chain_control/config/<unique_name>_waypoints.yaml [optional]: the waypoints that the chained system must follow if use_waypoints is set.
After you have looked at the proposed examples you can launch a given configuration by executing:
roslaunch qb_chain_control <unique_name>_control.launch
Every launch file has a structure close to the ones explained in details in qb SoftHand and qbmove packages. The only difference is that the argument robot_hardware (required by the combined_robot_hw) plays a crucial role when using several devices together, i.e. its names must match the ones of the loaded hardware interfaces to bring up everything correctly.
On the other hand, almost all the arguments used in the single-device launch files hold even for the chained system. Have a look at the following example:
Please remember that in a multi-device configuration, each qbrobotics® device connected to your system must have a unique ID.
