SIA20 project

This package is tutorial how to make robot arm ROS package.

A goal of sia20 package is to provide functions in order to control sia20(d/f).

DOCUMENT

Packages

• sia20_description This sia20_description subpackage includes foundation of sia20 like xacro and urdf, robot cad file(stl), and so on. If you are not familier with ROS system or this package, please start from this subpackage.

• sia20_control This sia20_control subpackage includes the configurations of actuator of sia20. If you would like to chagne the configuration, like pid gain, please visit this subpackage.

Tutorial

1. Rviz (Getting started in 30 sec)

First of all. take a look sia20 in rviz.

roslaunch sia20_description display.launch

2. Gazebo (Simulator)

As a next step, launch a simulation and move sia20.

roslaunch sia20_description gazebo.launch

Pleaes wait until gazebo launch.

Let's look the list of rostopic

rostopic list

You should look as below.

harumo@harumo-thinkpad-x1:~$ rostopic list
/clock
/gazebo/link_states
/gazebo/model_states
/gazebo/parameter_descriptions
/gazebo/parameter_updates
/gazebo/set_link_state
/gazebo/set_model_state
/rosout
/rosout_agg
/sia20/joint_b_position_controller/command
/sia20/joint_b_position_controller/pid/parameter_descriptions
/sia20/joint_b_position_controller/pid/parameter_updates
/sia20/joint_b_position_controller/state
/sia20/joint_e_position_controller/command
/sia20/joint_e_position_controller/pid/parameter_descriptions
/sia20/joint_e_position_controller/pid/parameter_updates
/sia20/joint_e_position_controller/state
/sia20/joint_l_position_controller/command
/sia20/joint_l_position_controller/pid/parameter_descriptions
/sia20/joint_l_position_controller/pid/parameter_updates
/sia20/joint_l_position_controller/state
/sia20/joint_r_position_controller/command
/sia20/joint_r_position_controller/pid/parameter_descriptions
/sia20/joint_r_position_controller/pid/parameter_updates
/sia20/joint_r_position_controller/state
/sia20/joint_s_position_controller/command
/sia20/joint_s_position_controller/pid/parameter_descriptions
/sia20/joint_s_position_controller/pid/parameter_updates
/sia20/joint_s_position_controller/state
/sia20/joint_states
/sia20/joint_t_position_controller/command
/sia20/joint_t_position_controller/pid/parameter_descriptions
/sia20/joint_t_position_controller/pid/parameter_updates
/sia20/joint_t_position_controller/state
/sia20/joint_u_position_controller/command
/sia20/joint_u_position_controller/pid/parameter_descriptions
/sia20/joint_u_position_controller/pid/parameter_updates
/sia20/joint_u_position_controller/state
/tf
/tf_static

Let's look each joints state such as angle, velocity, effort(stands for moment[N/m]).

rostopic echo /sia20/joint_states

Let's move joint using following command.

rostopic pub -1 /sia20/joint_s_position_controller/command std_msgs/Float64 "data 1.0"

You can see that sia20 moves in gazebo.

How to add a new gripper

reference

• gazebo ros control
• urdf turorial

0. Make your package

Make your new package. It may be convenient to make new package as subpackage of sia20.

sia20
  |--sia20_description
  |--sia20_control
  |--your_new_package!!

or, you can add new urdf and stl file like following.

sia20
  |-- sia20_description
  			|-- urdf
  			|     |-- sia20.urdf
  			|     |-- **your_gripper.urdf**
  			|
  			|-- mesh
  			      |-- **gripper.STL**

In order to make new gripper package, type following command.

mkdir ~/catkin_ws
cd ~/catkin_ws
catkin_create_pkg your_package controller_manager joint_state_controller robot_state_publisher
cd your_package
mkdir config
mkdir launch

1. Prepare gripper STL or COLLADA file.

Make your gripper CAD file and save as STL file.

2. Make new urdf or xacro

Make new urdf that includes sia20's urdf(sia20_description/sia20.urdf.xacro). And write configuration regarding to your gripper.

If you use Solidworks, you can make urdf file using sw_urdf_exporter. And include that urdf file and sia20's urdf into new one file.

Check list

• link
• joint
• transmission
• gazebo (especially robotNamespace)

Attach your gripper link to link tool0.

3. Verify your gripper in rviz

In order to look your gripper and sia20 in rviz, you can use existing launch file.

roslaunch sia20_description display model:=`$(find your_package)/urdf/sia20_with_gripper.urdf)'

4. Make configuration yaml file

Add configuration YAML file in config directory.

That configuration file tells ros parameter server some configuration as below. And ros_controller(pid controller or jont_state_controller) use such configuration.

• [Output] which joint information will be publish from ros_controller node.
• [Input] which joint use which control way(position, velocity, or effort) and pid gain in ros_controller node

Those configuration mush much with configuration in urdf or xacro that you wrote.

5. Make controller launch file

In order to attach pid controller to each joint and receive joint state(angle, velocity, and accelaletion),

set configuration in YAML file to ros parameter server using launch file.

• Load joint controller configuration from YAML file to parameter server
• Spawn pid controllers using configuration
• Spawn robot_state_publisher to convert joint state to tf transforms for rviz, etc

6. Make gazebo launch file

• load empty gazebo world
• load robot_description from urdf file and set to ros parameter server
• spawn robot model using urdf file.

7. launch in gazebo

8. make moveit configuration