WBC Controller#
The PAL Whole Body Control (WBC) is PAL’s implementation of the Stack of Tasks. This ROS controller includes a hierarchical quadratic solver able to accomplish different tasks with different priorities.
The default stack has the following set of constraints ordered by priority:
Joint Limits
Feet Pose constraints
Center of Mass Z position constraint
Center of Mass XY position constraint
Base Orientation
To start the Kinematic Whole Body Control execute the following command:
roslaunch kangaroo_wbc kangaroo_wbc.launch
To print the active set of constraints / objectives in the stack execute:
rosservice call /whole_body_kinematic_controller/get_stack_description
Once the controller is started it can be modified the COM reference and the Feet references by using Interactive Markers.
Open a terminal pointing to the robot and open RViz.
rviz
Then add some Interactive Markers, select the topic, and drag them to change their position or orientation.