Python simulation

This is the link to the Python simulation of the slip model: https://github.com/nooshin-kohli/python_simulation

Gazebo simulation and ROS

prerequisites

Considering ROS Melodic is installed on your Ubuntu 18.04, we will guide you to configure your workspace. If you don't have ROS Melodic installed, check this page http://wiki.ros.org/melodic/Installation/Ubuntu For using controllers you need to install ros_control and ros_controllers:

sudo apt update

sudo apt-get install ros-melodic-ros-control ros-melodic-ros-controllers

For using joint-state-publisher-gui:

sudo apt update

sudo apt install ros-melodic-joint-state-publisher-gui

Create your workspace

First, you need to configure a workspace using these commands:

mkdir <your_ws>

cd <your_ws>

catkin_make

For more information about Catkin workspace check this page http://wiki.ros.org/catkin/Tutorials/create_a_workspace Now It's time to clone the repository.

cd <your_ws>/src

git clone https://github.com/nooshin-kohli/simulation.git

There is no need to do all these steps all over again every time you want to use simulation. In the next part, you will learn how to run these codes.

Run simulation

Open new terminal

cd <your_ws>
source devel/setup.bash

To visualize the robot with a slider in rviz:

roslaunch first_leg urdf_rviz.launch

To visualize a robot with a slider in Gazebo:

roslaunch first_leg urdf_gazebo.launch

You can run rviz and the gazebo simultaneously. To do so run gazebo as mentioned above and in the new terminal type:

rviz rviz

Now in rviz add the tf plugin. See Topics in the new terminal write

rostopic list

Command a position to controllers

rostopic pub -1 /leg/jumper_position_controller/command std_msgs/Float64 <value in meters>

or for commanding one of the revolute joints:

rostopic pub -1 /leg/hip_joint_position_controller/command std_msgs/Float64 <value in radians>

*note: for commanding negative values (for calf_joint)

rostopic pub -1 /leg/calf_joint_position_controller/command std_msgs/Float64 -- <value in radians>

Run command node

After launching the robot in gazebo, open another terminal then go to your workspace

cd <your_ws>

and source setup.bash

source devel/setup.bash

To run the node for no slider mode enter

rosrun first_leg command.py

you will see a robot moving in the gazebo. *note: For permission denied error, open the terminal in the scripts directory and enter

chmod +x command.py