Planner Interface

The Planner Interface node is a wrapper for the AI Planner. The planner is called through a service, which returns true if a solution was found. This interface feeds the planner with a domain file and problem instance, and calls the planner with a command line specified by parameter. The problem instance can be supplied through subscription to a problem topic, or by file. The resulting solution, if one was found, can be written to a file and/or published on a ROS topic.

Contents:

• Launch
• Services
• Publishers

Launching a Planner Interface

There are implementations of the Planner Interface node used with the planners:

An example launch file showing all the parameters is shown below:

<launch>

	<!-- arguments -->
	<arg name="node_name"            default="rosplan_planner_interface" />
	<arg name="use_problem_topic"    default="true" />
	<arg name="problem_topic"        default="/rosplan_problem_interface/problem_instance" />
	<arg name="planner_topic"        default="planner_output" />
	<arg name="domain_path"          default="$(find rosplan_demos)/common/domain_turtlebot_demo.pddl" />
	<arg name="problem_path"         default="$(find rosplan_demos)/common/problem.pddl" />
	<arg name="data_path"            default="$(find rosplan_demos)/common/" />
	<arg name="planner_command"      default="timeout 10 $(find rosplan_planning_system)/common/bin/popf DOMAIN PROBLEM" />


	<!-- planner interface -->
	<node name="$(arg node_name)" pkg="rosplan_planning_system" type="popf_planner_interface" respawn="false" output="screen">

		<!-- read problem from topic (instead of from file) -->
		<param name="use_problem_topic" value="$(arg use_problem_topic)" />

		<!-- ros topics -->
		<param name="problem_topic" value="$(arg problem_topic)" />
		<param name="planner_topic" value="$(arg planner_topic)" />

		<!-- directory for files -->
		<param name="domain_path" value="$(arg domain_path)" />
		<param name="problem_path" value="$(arg problem_path)" />
		<param name="data_path" value="$(arg data_path)" />

		<!-- to run the planner -->
		<!-- planner command replaces strings 'DOMAIN' and 'PROBLEM' with paths -->
		<param name="planner_command" value="$(arg planner_command)" />
	</node>

</launch>

Services

Service: planning_server
Type: std_srvs/Empty
The service is intended to call a planner:

• The command line in parameter planner_command will be run.
• The domain_path parameter will replace the string ‘DOMAIN’ in the command line.
• If use_problem_topic is true, then the last problem instance published on the problem topic will be passed to the planner, otherwise the problem will be read from problem_path.
• In either case, the problem path will replace the string ‘PROBLEM’ in the command line.
• The plan and any files generated by the planner will be written to data_path.
• The service returns when the command is finished, and returns true if a plan was found. The plan is published as a std_msgs/string on the planner topic.

Service: planning_server_params
Type: rosplan_dispatch_msgs/PlanningService
The planning_server is called, overriding the node parameters with the arguments of the service.

Publishers

Topic: planner_output
Type: std_msgs/String
If a plan is found by the planner, it is published on this topic.