Robots

To create a new Robot node, one can either use the UI (instructions) or create the robot programmatically with the following commands. The convenience function vtkMRMLROS2NodeNode::CreateAndAddRobotNode was added to the module logic that accepts three arguments (std::string robotName, std::string parameterNodeName, std::string parameterName).

PythonC++

rosLogic = slicer.util.getModuleLogic('ROS2')
rosNode = rosLogic.GetDefaultROS2Node()
rosNode.CreateAndAddRobotNode('PSM','PSM1/robot_state_publisher','robot_description') # Using the PSM as an example

The robot node creates an observer on the parameter node that contains the robot description. If the parameter node is modified (indicating that the robot description is available), it begins the process of loading the visuals for the robot into the scene. This process involves: parsing the URDF file, creating a list of TF2 lookups in the scene, creating the models for each link of the robot and applying the correct color and offset position relative to the base of the robot. Once the visuals have been created, the TF2 lookups start to check the TF2 buffer and update the position of the model according to the joint state publisher.

To remove the robot, use the “Remove robot” button on the UI or the method vtkMRMLROS2NodeNode::RemoveAndDeleteRobotNode. This method takes up to 5 parameters:

• the robot name (std::string)

• the parameter node name (std::string)

• parameter name (std::string, default is “robot_description”)

• fixed frame, aka reference frame used in RViz (std::string, default is “”),

• tf prefix (std::string, default is “”);