Perlin Noise Node

Assorted ROS nodes that implement the perlin_noise_filter package to add Perlin Noise to the motion of user specified joints.

Currently working with:

• Aldebaran Nao

Note: Working in ROS indigo, other versions have not been tested

Getting Started

Filter Configuration

See perlin_noise_filter for instructions on configuring the Perlin Noise Filter.

Parameter Server

perlin_noise_node uses the Parameter server to retrieve configuration parameters at runtime. perlin_noise_node sets these parameters in the .launch file that then loads a YAML file with the command-line tool, rosparam. Ultimately, this allows the user to quickly tweak commonly used variables such as freq, speed, and perlin_joints (the joints that Perlin noise is being applied to) without having to recompile the whole project.

Existing Robot Instructions

If the robot you're working with already has a perlin_noise_node configuration, you're in luck. First, feel free to tweak the parameter server configuration in launch/robotName.yaml and change any values to your liking.

Next, you'll need to start roscore

roscore

Launch your robot's corresponding perlin_noise_node

roslaunch perlin_noise_node robotName.launch

Nao only: Enable joint stiffness

rosservice call /nao_robot/pose/body_stiffness/enable "{}"

New Robot Instructions

New robots require the following:

• perlin_base.cpp implementation
• Parameter Server configuration
• Launch file

perlin_base.cpp implementation

perlin_base.cpp and it's corresponding header file, perlin_base.h contain the majority of setup functionality for each robot's node. This includes initializing the filter chain (perlin_noise_filter setup), and setting the node parameters contained in the robot's .launch file. perlin_base is also an abstract base class that each node is to inherit from and implement it's pure virtual function, timerCallback.

Essentially, timerCallback should contain the implementation specific code that calls the Perlin Noise filter and publishes the results in a new message.

See nao.cpp for an example of implementing perlin_base

Parameter Server configuration

A YAML file that will be loaded with rosparam should be created and include the following parameters. You're free to add any robot-specific parameters, also.

• freq (double, default: Required)

  Frequency of message publishing

• speed (double, default: Required)

  Motion speed of robot

• perlin_joints (std::Vector<std::string>, default: Required)

  Joint names that Perlin noise will be applied to

• joint_names (std::Vector<std::string>, default: Required)

  All joints names (required for message being published)

Example Configuration

freq: .5
speed: .025
perlin_joints: ['HeadYaw', 'HeadPitch']
joint_names: ['HeadYaw', ...., 'RHand']

Launch file

roslaunch allows for easy launching of multiple ROS nodes, as well as setting parameters on the Parameter server with the YAML configuration file described above. You'll need to create a .launch file to launch your robot's node and set the Parameter server parameters.

Example Configuration

<launch>
  <!-- The C++ nao_pn_gen node will publish a message with perlinized motion. -->
  <node pkg="perlin_noise_node" type="nao_pn_gen" name="nao_pn_gen">
    <rosparam command="load" file="$(find perlin_noise_node)/launch/nao.yaml" />
  </node>

  <!-- Load default values into Filter Chain. Add additional/custom robot launch configs below -->
  <rosparam command="load" file="$(find perlin_noise_node)/launch/filter.yaml" />
</launch>

Installing

Note: A working catkin workspace is required for installation. For more information, see catkin.

Make sure you have sourced the correct setup.bash file for your ROS distribution already

Go to workspace src directory

cd /path/to/your/catkin_ws/src

Checkout the perlin_noise_node repository

git clone https://github.com/jakedex/perlin_noise_node

Then make sure you have all dependencies installed

cd /path/to/your/catkin_ws
rosdep install --from-paths src --ignore-src --rosdistro indigo

Now build

catkin_make

After sourcing /path/to/your/catkin_ws/devel/setup.bash you should now be able to use the perlin_noise_node package.

License

This project is licensed under the BSD License - see the LICENSE.txt file for details