Use Niryo robot through simulation

The simulation allows to control a virtual Ned directly from your computer.

Ned in Gazebo Simulation

Ned in Gazebo Simulation

In this tutorial, you will learn how to setup a robot simulation on a computer.

Note

You can use Niryo Studio with the simulation. To do so, you just have to connect Niryo Studio to “Localhost”.

Simulation environment installation

Attention

The whole ROS Stack is developed and tested on ROS Melodic which requires Ubuntu 18.04 to run correctly. The using of another ROS version or OS may lead to malfunctions of some packages. Please follow the steps in Ubuntu 18 Installation to install a working environment.

Simulation usage

Important

  • Hardware features are simulated as if you were using a real robot.
  • The data returned by the faked drivers is arbitrary and immutable. Among this data, you will have : voltage, temperature, error state (always 0), ping (always true), end effector state (immutable)
The simulation is a powerful tool allowing to test new programs directly on your computer which prevents to transfer new code on the robot.
It also helps for developing purpose → no need to transfer code, compile and restart the robot which is way slower than doing it on a desktop computer.

Without physics - No visualization

This mode is mainly for simulation and tests purpose, bringing you in the closest state as possible to a real robot control. It is available for all currently supported architectures. You can access it by using the commands:

  • One simulation:

    roslaunch niryo_robot_bringup niryo_one_simulation.launch

  • Ned simulation:

    roslaunch niryo_robot_bringup niryo_ned_simulation.launch

  • Ned2 simulation:

    roslaunch niryo_robot_bringup niryo_ned2_simulation.launch

This mode is useful if your CPU capacity is limited or if you don’t have X server available.

Options

This mode is the more flexible one, as it provides all the possible options to customize the simulation. For the other simulation modes (with RViz and Gazebo) we will just force some of these parameters to specific values.

Simulation without visualization Options
Name Default Value Description
log_level INFO Log level to display for ROS loggers
ttl_enabled true Enable or disable the TTL bus usage. This feature is used for debug mainly and can lead to an unstable stack.
can_enabled true Enable or disable the CAN bus usage. This feature is used for debug mainly and can lead to an unstable stack.
debug false Launch in debug mode. For development and debug only.
conf_location version.txt Location of the version.txt file. A path to the file is required.
simu_gripper true Simulate the presence of a gripper id 11 on the bus
simu_conveyor true Simulate the presence of a conveyor (CAN for One and Ned, TTL for Ned2, based on configuration files) on the bus
vision_enabled true Enable the Vision Kit
gazebo false Enable gazebo specific parameters (However it does not launch gazebo, use gazebo specific launch file for that)

Without physics - RViz Visualization

A simple visualization of the robot is possible via a tool called Rviz. This application will simulate the robot with its correct geometry and positions but without physics to avoid using too much CPU.

Control with trackbar

This visualization allows an easy first control of the robot, and helps to understand joints disposal. You can access it by using the command:

roslaunch niryo_robot_description display.launch

Rviz should open with a window containing 6 trackbars. Each of these trackbars allows to control the corresponding joint.

Ned on Rviz

Example of trackbars use.

Control with ROS

Not only Rviz can display the robot, but it can also be linked with ROS controllers to show the robot’s actions from ROS commands!
This method can help you debug ROS topics, services and also, API scripts.

To run it:

roslaunch niryo_robot_bringup desktop_rviz_simulation.launch
Ned on RViz

Rviz opening, with the robot ready to be controlled with ROS!

RViz Visualization options

Table of RViz launch Options
Name Default Value Description
log_level INFO Log level to display for ROS loggers
hardware_version ned Use the parameters dedicated to this specific hardware_version. Possible values are “one”, “ned” and “ned2”
debug false Launch in debug mode. For development and debug only.
gui true Enable the gui visualization
conf_location version.txt Location of the version.txt file. A path to the file is required.
simu_gripper false Simulate the presence of a gripper id 11 on the bus (Visualisation of the tool will not be visible, whatever the value of this parameter)
simu_conveyor false Simulate the presence of a conveyor (Visualisation of the conveyor will not be visible, whatever the value of this parameter)

With physics - Gazebo Simulation

For the simulation, Ned uses Gazebo, a well known tool among the ROS community. It allows:

  • Collision.
  • World creation → A virtual environment in which the robot can deal with objects.
  • Gripper & Camera using.

The Niryo Gripper 1 has been replicated in Gazebo. The Camera is also implemented.

Note

Gazebo also generates camera distortion, which brings the simulation even closer from the reality!

Launch Gazebo simulation

A specific world has been created to use Ned in Gazebo with 2 workspaces.

To run it:

roslaunch niryo_robot_bringup desktop_gazebo_simulation.launch
Ned on Gazebo

Gazebo view, with the robot ready to be controlled with ROS!

Note

You can edit Gazebo world to do your own! It’s placed in the folder worlds of the package niryo_robot_gazebo.

Gazebo Simulation options

The user can disable 3 things by adding the specific string to the command line:

  • the Gazebo graphical interface: gui:=false.
  • the Camera & the Gripper - Vision & Gripper wise functions won’t be usable: gripper_n_camera:=false.

Hint

Gazebo can be very slow. If your tests do not need Gripper and Camera, consider using Rviz to alleviate your CPU.

Table of Gazebo launch Options
Name Default Value Description
log_level INFO Log level to display for ROS loggers
hardware_version ned Use the parameters dedicated to this specific hardware_version. Possible values are “one”, “ned” and “ned2”
debug false Launch in debug mode. For development and debug only.
gui true Enable the gui visualization
conf_location version.txt Location of the version.txt file. A path to the file is required.
gripper_n_camera true Simulate the presence of a gripper id 11 and a camera on the bus
simu_conveyor true Simulate the presence of a conveyor (Visualisation of the conveyor will not be visible, whatever the value of this parameter)