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--- doc:srdl2_tutorial [2014/11/27 16:24] – [Semantic Robot Description Language] admin
+++ doc:srdl2_tutorial [2014/11/27 17:05] (current) – [Matching requirements to capabilities] admin
@@ Line 22: / Line 22: @@
   * Robot model: Description of a concrete robot instance including its kinematic structure (auto-generated from URDF file), other hardware/software components and hardcoded capabilities
   * Task model: Description of the concrete task at hand, using the action classes defined in the srdl-action ontology
+===== Startup =====
+<code prolog>
+$ rosrun rosprolog rosprolog knowrob_srdl
+% Load SRDL model of the PR2 and Baxter robots
+?- owl_parse('package://knowrob_srdl/owl/PR2.owl').
+?- owl_parse('package://knowrob_srdl/owl/baxter.owl').
+% Load an example task description for serving a drink
+?- register_ros_package(knowrob_actions).
+?- owl_parse('package://knowrob_actions/owl/serve_drink.owl').
+</code>
 ===== Components and capabilities of a robot =====
 Read all components of a robot. There is no distinction between robots and components any more, robots are just complex components that consist of many parts.
-  ?- srdl2:sub_component(tumrosie:'TUM_Rosie1', Sub).
+<code prolog>
-  Sub = 'http://ias.cs.tum.edu/kb/TUM_Rosie.owl#TUM_Rosie_WheeledOmnidirPlatform1' ;
+?- sub_component(pr2:'PR2Robot1', Sub).
-  Sub = 'http://ias.cs.tum.edu/kb/TUM_Rosie.owl#TUM_Rosie_Torso1' .
+Sub = pr2:pr2_base ;
- ...
+Sub = pr2:pr2_left_arm ;
+Sub = pr2:pr2_right_arm
+[...]
+</code>
+Filter the list of components to only those of a given type, e.g. a //Camera//:
+<code prolog>
+?- sub_component(pr2:'PR2Robot1', Sub),
+   owl_individual_of(Sub, srdl2comp:'Camera').
+Sub = pr2:pr2_high_def_frame ;
+Sub = pr2:pr2_high_def_frame ;
+Sub = pr2:pr2_wide_stereo_l_stereo_camera_frame ;
+Sub = pr2:pr2_wide_stereo_r_stereo_camera_frame ;
+Sub = pr2:pr2_narrow_stereo_l_stereo_camera_frame
+[...]
+</code>
+Read all properties of a component:
+<code prolog>
+?- sub_component(pr2:'PR2Robot1', Sub), owl_has(Sub, P, O).
+Sub = pr2:pr2_high_def_frame,
+Sub = pr2:pr2_high_def_frame,
+P = srdl2comp:update_rate,
+O = literal(type('http://qudt.org/vocab/unit#Hertz','20.0')) ;
+Sub = pr2:pr2_high_def_frame,
+P = srdl2comp:frameName,
+O = literal(type(xsd:string,high_def_optical_frame)) ;
+Sub = pr2:pr2_high_def_frame,
+P = srdl2comp:hfov,
+O = literal(type(xsd:string,'0.785398163397'))
+[...]
+</code>
 Check whether a component of a certain type exists on a robot (or, in general, as part of another component):
-  ?- srdl2:comp_type_available(tumrosie:'TUM_Rosie1', CompT).
+<code prolog>
-  CompT = 'http://ias.cs.tum.edu/kb/srdl2-comp.owl#VectorFieldArmController' ;
+?- comp_type_available(pr2:'PR2Robot1', srdl2comp:'Camera').
-  CompT = 'http://ias.cs.tum.edu/kb/srdl2-comp.owl#ArmMotionController' ;
+true
-  CompT = 'http://ias.cs.tum.edu/kb/srdl2-comp.owl#MotionControllerComponent' ;
-  ...
-Check which capabilities exists on a robot
-  ?- srdl2:cap_available_on_robot(Cap, tumrosie:'TUM_Rosie1').
-  Cap = 'http://ias.cs.tum.edu/kb/srdl2-cap.owl#ArmMotionCapability' ;
-  Cap = 'http://ias.cs.tum.edu/kb/srdl2-cap.owl#BaseMotionCapability' ;
-  Cap = 'http://ias.cs.tum.edu/kb/srdl2-cap.owl#GripperMotionCapability' ;
-  Cap = 'http://ias.cs.tum.edu/kb/srdl2-cap.owl#HeadMotionCapability' ;
-  ...
+?- comp_type_available(pr2:'PR2Robot1', Sub).
+Sub = srdl2comp:'Pr2Base' ;
+Sub = srdl2comp:'WheeledBase' ;
+Sub = srdl2comp:'MobileBase' ;
+[...]
+</code>
+Check which capabilities exists on a robot:
+<code prolog>
+?- cap_available_on_robot(Cap, pr2:'PR2Robot1').
+Cap = srdl2cap:'GraspingCapability' ;
+Cap = srdl2cap:'ObjectManipulationCapability' ;
+[...]
+</code>
 ===== Requirements of an action =====
 Capabilities an action depends on:
-  ?- srdl2:required_cap_for_action(tablesetting:'TableSetting', Cap).
-  Cap = 'http://ias.cs.tum.edu/kb/srdl2-cap.owl#PuttingDownAnObjectCapability' ;
+<code prolog>
-  Cap = 'http://ias.cs.tum.edu/kb/srdl2-cap.owl#PickingUpAnObjectCapability' ;
+?- required_cap_for_action(serve_drink:'ServeADrink', C).
-  Cap = 'http://ias.cs.tum.edu/kb/srdl2-cap.owl#BaseMotionCapability' ;
+C = srdl2cap:'BaseMotionCapability' ;
-  Cap = 'http://ias.cs.tum.edu/kb/srdl2-cap.owl#ArmMotionCapability' ;
+C = srdl2cap:'ArmMotionCapability' ;
-  ...
+C = srdl2cap:'GraspingCapability' ;
+C = srdl2cap:'GripperMotionCapability'
+[...]
+</code>
 Components an action depends on (either directly or via required capabilities that depend on these components)
-  ?- srdl2:required_comp_for_action(tablesetting:'TableSetting', Comp).
+<code prolog>
-  Comp = 'http://ias.cs.tum.edu/kb/srdl2-comp.owl#MobileBase' ;
+?- required_comp_for_action(serve_drink:'ServeADrink', C).
-  Comp = 'http://ias.cs.tum.edu/kb/srdl2-comp.owl#ArmMotionController' ;
+C = srdl2comp:'MobileBase' ;
-  Comp = 'http://ias.cs.tum.edu/kb/srdl2-comp.owl#ArmComponent' ;
+C = srdl2comp:'ArmMotionController' ;
-  ...
+C = srdl2comp:'ArmComponent' ;
+C = srdl2comp:'ManipulationEntity'
+[...]
+</code>
 ===== Missing components or capabilities =====
-  ?- missing_cap_for_action(tablesetting:'TableSetting', tumrosie:'TUM_Rosie1', Cap).
+<code prolog>
-  Cap = 'http://ias.cs.tum.edu/kb/srdl2-cap.owl#PuttingDownAnObjectCapability' ;
+% No components nor capabilities are missing for the ServeADrink action on the PR2:
-  Cap = 'http://ias.cs.tum.edu/kb/srdl2-cap.owl#PickingUpAnObjectCapability' ;
+?- missing_comp_for_action(serve_drink:'ServeADrink', pr2:'PR2Robot1', C).
+false.
-  ?- missing_comp_for_action(tablesetting:'TableSetting', tumrosie:'TUM_Rosie1', Comp).
-  false.
+?- missing_cap_for_action(serve_drink:'ServeADrink', pr2:'PR2Robot1', C).
+false.
-===== Matching requirements to capabilities =====
+% The Baxter robot, in contrast, cannot perform the task due to lacking navigation abilities:
+?- missing_cap_for_action(serve_drink:'ServeADrink', baxter:baxter_baxter1, C).
+C = srdl2cap:'BaseMotionCapability'
+</code>
+===== Behind the scenes: Implementation of the matching procedures =====
 The matching can effectively reduced to the following statement:
+<code prolog>
   missing_cap_for_action(Action, Robot, Cap) :-
      required_cap_for_action(Action, Cap),
      \+ cap_available_on_robot(Cap, Robot).
-A missing capability is thus defined as one that is required by an action, but not provided by the robot. Required means that either the action itself or any sub-action has a dependency on this capability:
+</code>
+A missing capability is thus defined as one that is required by an action but not provided by the robot. "Required" thereby means that either the action itself or any sub-action has a dependency on this capability:
+<code prolog>
   required_cap_for_action(Action, Cap) :-
      class_properties(Action, srdl2cap:'dependsOnCapability', Cap).
@@ Line 82: / Line 149: @@
      plan_subevents_recursive(Action, SubAction),
      class_properties(SubAction, srdl2cap:'dependsOnCapability', Cap).
+</code>
-There are three possibilities to express that a capability is available on a robot: Either it is asserted to be available for the whole class of robots (e.g. every PR2 has a holonomic base), for a specific robot instance, or it can be concluded that the capability should be available because all specified dependencies on components or other capabilities are fulfilled:
+There are three possibilities to express that a capability is available on a robot: Either it is asserted to be available for the whole class of robots (e.g. every PR2 has a mobile base), for a specific robot instance, or it can be concluded that the capability should be available because all specified dependencies on components or other capabilities are fulfilled:
+<code prolog>
   % capability asserted for robot instance
   cap_available_on_robot(Cap, Robot) :-
@@ Line 104: / Line 173: @@
      forall( class_properties(Cap, srdl2cap:'dependsOnCapability', SubCap),
              cap_available_on_robot(SubCap, Robot) ).
+</code>
 The matching procedure is equivalent for components.