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tutorials:beginner:location_designators_2 [2017/09/07 12:49] – Added rule for matching process module of going-to designator. cpotutorials:beginner:location_designators_2 [2022/02/25 23:20] (current) – [Using location designators with the TurtleSim] schimpf
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 **Description:** in this tutorial you will learn about location designators, how to create and resolve them. You will expand a process module to make use of the location designator. **Description:** in this tutorial you will learn about location designators, how to create and resolve them. You will expand a process module to make use of the location designator.
  
-**Previous Tutorial:** [[tutorials:beginner:assigning_actions|Automatically choosing a process module for an action]]+**Previous Tutorial:** [[tutorials:beginner:assigning_actions_2|Automatically choosing a process module for an action]]\\ 
 +**Next Tutorial:** [[tutorials:beginner:high_level_plans|Writing plans for the TurtleSim]]
  
 +To run the code in the tutuorial the roscore and the turtlesim need to be started over the terminal. Each in their own tab.
 +<code bash>
 +$ roscore
 +</code>
 +<code bash>
 +$ rosrun turtlesim turtlesim_node
 +</code>
 +
 +And in the REPL the following commands should be executed:
 +<code lisp>
 +CL-USER>(ros-load:load-system "cram_my_beginner_tutorial" :cram-my-beginner-tutorial)
 +...
 +CL-USER>(in-package :tut)
 +</code>
 ===== Location designators: an overview ===== ===== Location designators: an overview =====
  
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 ===== Location designator generators ===== ===== Location designator generators =====
  
-Let's create a new file called ''location-designators.lisp'' in our tutorial's ''src'' directory and add it to the ''*.asd'' file with ''process-modules'' depending on it. The resulting ''cram-beginner-tutorial.asd'' should now look like this:+Let's create a new file called ''location-designators.lisp'' in our tutorial's ''src'' directory and add it to the ''*.asd'' file. The resulting ''cram-my-beginner-tutorial.asd'' should now look like this:
  
 <code lisp> <code lisp>
-(defsystem cram-beginner-tutorial+(defsystem cram-my-beginner-tutorial
   :depends-on (roslisp cram-language turtlesim-msg turtlesim-srv cl-transforms geometry_msgs-msg cram-designators cram-prolog   :depends-on (roslisp cram-language turtlesim-msg turtlesim-srv cl-transforms geometry_msgs-msg cram-designators cram-prolog
                        cram-process-modules cram-language-designator-support cram-executive)                        cram-process-modules cram-language-designator-support cram-executive)
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        (make-designator :location '((:vertical-position :bottom) (:horizontal-position :left))))        (make-designator :location '((:vertical-position :bottom) (:horizontal-position :left))))
 TUT> goal-desig TUT> goal-desig
-#<LOCATION-DESIGNATOR ((:VERTICAL-POSITION :BOTTOM) +#<A LOCATION 
-                       (:HORIZONTAL-POSITION :LEFT)) {1008548CD3}>+​    (VERTICAL-POSITION BOTTOM) 
 +    (HORIZONTAL-POSITION LEFT)>
 </code> </code>
  
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 </code> </code>
  
-Depending on the random number generator we will get some or none of the solutions rejected and, therefore, ''<='' number of valid solutions for our designator ''another-goal''.+Depending on the random number generator we will get some or none of the solutions rejected and, therefore, ''<='' number of valid solutions for our designator ''another-goal''. That means, you might get a different number of solutions than what we got: we got 3 but you might be 4 or 5 or something else. 
  
  
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 <code lisp> <code lisp>
-(def-fact-group goal-motions (motion-desig) +(def-fact-group goal-motions (motion-grounding) 
-  (<- (motion-desig ?desig (go-to ?point))+  (<- (motion-grounding ?desig (go-to ?point))
     (desig-prop ?desig (:type :going-to))     (desig-prop ?desig (:type :going-to))
     (desig-prop ?desig (:goal ?point))))     (desig-prop ?desig (:goal ?point))))
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          (let ((target-point (reference motion)))          (let ((target-point (reference motion)))
            (roslisp:ros-info (turtle-process-modules)            (roslisp:ros-info (turtle-process-modules)
-                             "Goint to point ~a." target-point)+                             "Going to point ~a." target-point)
            (move-to target-point)))))))            (move-to target-point)))))))
  
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                                (horizontal-position ?horizontal-position)                                (horizontal-position ?horizontal-position)
                                (vertical-position ?vertical-position)))                                (vertical-position ?vertical-position)))
-               (goal (desig:a motion (type :going-to) (:goal ?area))))+               (goal (desig:a motion (type going-to) (goal ?area))))
           (cram-executive:perform goal))))))           (cram-executive:perform goal))))))
 </code> </code>
  
-In ''goto-location'' we use ''perform'', which means we have to make sure the right process module for our ''going-to'' designator can be found. For that we add a rule to the fact-group ''available-turtle-process-modules'':+In ''goto-location'' we use ''perform'', which means we have to make sure the right process module for our ''going-to'' designator can be found. For that we add a rule to the fact-group ''available-turtle-process-modules'' from the ''selecting-process-modules.lisp'' file. The file should now look like this:
  
 <code lisp> <code lisp>
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 </code> </code>
  
-It's the same as the other ones. If the type of ''?desig'' is ''going-to'', the rule applies and ''turtlesim-navigation'' gets selected-+It's the same as the other ones. If the type of ''?desig'' is ''going-to'', the rule applies and ''turtlesim-navigation'' gets selected.
  
 Now let's give it a go. Reload the tutorial in ''roslisp_repl'' then in the command line of the REPL type: Now let's give it a go. Reload the tutorial in ''roslisp_repl'' then in the command line of the REPL type:
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 [(ROSLISP TOP) INFO] 1501153969.641: master URI is 127.0.0.1:11311 [(ROSLISP TOP) INFO] 1501153969.641: master URI is 127.0.0.1:11311
 [(ROSLISP TOP) INFO] 1501153970.649: Node startup complete [(ROSLISP TOP) INFO] 1501153970.649: Node startup complete
-[(TURTLE-PROCESS-MODULES) INFO] 1501153970.689: TurtleSim navigation invoked with motion designator `#<MOTION-DESIGNATOR ((TYPE +[(TURTLE-PROCESS-MODULES) INFO] 1562698457.619: TurtleSim navigation invoked with motion designator `#<A MOTION 
-                                                                           GOING-TO) +    (TYPE GOING-TO) 
-                                                                          (GOAL +    (GOAL #<A LOCATION 
-                                                                           #<LOCATION-DESIGNATOR +    (HORIZONTAL-POSITION RIGHT) 
-                                                                             ((HORIZONTAL-POSITION +    (VERTICAL-POSITION TOP)>)>'. 
-                                                                               RIGHT) +[(TURTLE-PROCESS-MODULES) INFO] 1501153970.691: Going to point #<3D-VECTOR (10.131428718566895d0 8.874866485595703d0 0.0d0)>.
-                                                                              (VERTICAL-POSITION +
-                                                                               TOP)) +
-                                                                             {1005139363}>)) {1005139703}>'. +
-[(TURTLE-PROCESS-MODULES) INFO] 1501153970.691: Goint to point #<3D-VECTOR (10.131428718566895d0 8.874866485595703d0 0.0d0)>.+
 T T
 +</code>
 +
 +If you already had a running node in the REPL, you might get the error shown below but that is absolutely normal: ROS simply notifies you that it is going to shut down the previous node and start a new one.
 +<code lisp>
 +WARNING:
 +   Before starting node, node-status equalled RUNNING instead of :shutdown.  Shutting the previous node invocation down now.
 </code> </code>