Action Client Panel

The Action Client panel eases the task of send goals to an action server. The panel provides a GUI for selecting actions, setting their parameters, sending action goals and monitoring progress of action execution. It has the following features:

• Drop-down list of all supported actions and their parameters.
• Support for loading known parameter values from multiple sources.
• Suport for typing in the parameter values providing suggestions of known parameter values.
• Display of action execution status.
• Support for four types of parameters: boolean, integer, float and enumerations.

Authors:

1. Sushant Vijay Chavan
2. Ahmed Faisal Abdelrahman

The following GIF demonstrates the action client panel tool being used to send action commands to a KUKA youBot on RViz:

Instructions

Using the Action Client Panel:

The panel can be used by following these steps:

• Start Rviz and add the ActionClientPanel from the "Panels" tab. Panels -> Add New Panel -> ActionClientPanel
• Select a desired action form the drop-down list in the newly added ActionClientPanel.
• Set the required parameters for executing the action.
• Click on the Send Goal button.
• The status of action execution will be then displayed below the Send Goal button.

Adding new action clients

The Action Client Panel can be easily extended to support new actions clients. All the supported actions clients and their parameters are described in the ActionClients.yaml file. Follow the below steps to add new action clients:

• Extend the ActionClients.yaml file. For example, to add a place_object action along with its parameters add the below lines:

    place_object:
      object: string
      location: enum

• Implement a new class for the action client that derives from the ClientBase class. Check the MoveBaseClient class for an example.
• Add a new callback method to create an object of the class implemented in the previous step. Check the executeMoveBaseAction method of ActionClientPanel class for an example.
• Extend the handleButton method in ActionClientPanel class to register this new callback function. For example, add the below lines to the existing if-else block

    else if (actionName == "pick_object")
      executePickObjectAction();

Setting up enumerations (drop-down lists)

Enumerations are used in order to provide drop-down lists in the ActionClientPanel. We support two type of enum initializations:

• Enum values declared explicitly in the ActionClients.yaml file.
  • Example

      robot_platform:
        - platform_right
        - platform_left
        - platform_middle

• Enum values lazily loaded from another source on demand.
  • For example the navigation goals specified in the active navigation_goals.yaml file.
  • In order to declare such a lazily loaded enum parameter in the ActionClients.yaml file, declare its type as enum indicating that it will be loaded later. For example location: enum

The method getEnumStrings in the ActionClientPanel class handles the loading of enum values from the correct location. Do not forget to update this method whenever a new enum parameter is added or an existing enum parameter is changed in the ActionClients.yaml file.

Architecture