Executor

The Executor module is responsible for requesting a plan to the Planner, and carry it out, calling to the nodes in the client application that implements the actions. While executing each action, it checks the requisites (At Start, At End and Over all, in case of durative Actions). If the requirements are not meet, it cancels the plan execution. It also is responsible for applying the effects of the actions, requesting updates to the Problem Expert.

The main class of Executor is plansys2::ExecutorNode, which is instantiated from executor_node.cpp.

The executions of plans are carried out using ROS2 actions, in particular, plansys2_msgs::action::ExecutePlan. Take note that the goal must be already in the Domain Expert.

ExecutorNode ask for the domain and problem, and ask for a plan to the Planner. For each action in the plan, ExecuterNode creates a plansys2::ActionExecutor. The lifetime of this object is only one action. This object calls the actions implemented in the client appliciation using the ROS2 actions plansys2_msgs::action::ExecuteAction. Each client action implementation can use the class plansys2::ActionExecutorClient to avoid the complexity of managing ROS2 actions.

Using the feedback information from plansys2_msgs::action::ExecuteAction, feedback for plansys2::ExecutorNode is composed and returned to plansys2::ExecutorClient. It contains the current action in the plan and the progress in the currently executing action.

Next graph shows an example of the execution flow:

Actions:

• /execute_plan [plansys2_msgs::action::ExecutePlan]

(in ActionExecutorClient)

• /${ACTION_NAME}[plansys2_msgs::action::ExecuteAction]

Subscribed topics:

(in ActionExecutor)

• /problem_expert/update_notify [std_msgs::msg::Empty]

Changelog for package plansys2_executor

1.0.9 (2021-03-15)

• Disable boost in tests
• Contributors: Francisco Martin Rico

1.0.8 (2021-03-12)

• Change default ZMQ ports
• Removing whitespace.
• Simplified logic.
• Update API for FutureReturnCode
• Handling edge cases of action failure and preventing overriding completion percentage on action completion.
• Publishing generated plan as a dotgraph on a string topic.
• Fix BT creation; parallel deps actions
• Fixing feedback control
• Action execution refactoring
• Moving Utils file to plansys2_problem_expert since all the functions are checking information in the problem or modifying the problem.
• utils-bug: Fixing bug in OR case of evaluate function in plansys2_executor/Utils.cpp.
• Making zmq error message more generic to reflect that there are multiple possible reasons for a BT::LogicError to be thrown.
• Add support to plansys2_executor/ExecutorNode for visualizing the behavior trees in Groot.
• Moving publisher on_activate call to the ExecutorNode::on_activate callback.
• Add support for numeric conditions and effects.
• Monitorization info
• Remove an unreshable return
• Adding actor checker in terminal
• Improving BTActions
• Fix repeated nodes
• New Graph creation Algorithm
• Debugging
• Added negative predicates support
• Namespaced action_hub
• Contributors: Alexander Xydes, Fabrice Larribe, Francisco Martin Rico, Greg Kogut, Josh Zapf

1.0.7 (2021-01-04)

• Making explicit dependencies
• Contributors: Francisco Martin Rico

1.0.6 (2020-12-29)

• Disable boost functions
• Contributors: Francisco Martin Rico

1.0.5 (2020-12-28)

• Migration to c++17
• Contributors: Francisco Mart