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--- cs:ai:start [2018/02/23 18:30]
Mike Bykhovtsev Tweak
+++ cs:ai:start [2022/09/22 18:57] (current)
Justin Pilgrim [AI]
@@ Line 1: / Line 1: @@
 ====== AI ======
+Main function of AI on the sub is to make decisions of what the sub should do based on given data from topics like sensors, vision, data, etc. It is using hierarchical state machine, which allows it to cover majority of cases it will face.
-<WRAP alert>
-This page is **stale** and needs to be reviewed. It may be deleted or radically changed in the near future.
-</WRAP>
 ===== Overview =====
-Current AI uses SMACH package that is in ROS. SMACH is a task-level architecture for rapidly creating complex robot behavior. At its core, SMACH is a ROS-independent Python library to build hierarchical state machines.
+Current AI uses [[http://wiki.ros.org/smach | SMACH]] package that is in ROS. SMACH is a task-level architecture for rapidly creating complex robot behavior. At its core, SMACH is a ROS-independent Python library to build hierarchical state machines.
 Advantages of SMACH are:
-  - rapid development, ability to create complex state machines;
+  - rapid development, ability to create complex state machines
   - ability to quickly change state machines without big code changes
-  - explicitly define outcomes of every state thus covering most or all possible situations.
+  - explicitly define outcomes of every state thus covering most or all possible situations
 ===== Current AI =====
 Our current AI was re-written using SMACH. There are several utility files such as:
   - gate_util.py - all states that are used by gate AI, they are generic.
-  - util.py - contains utility functions for vision to filter labels, get N most probably, normalize coordinates from vision, or wrap yaw. **Note that vision will be changed in future, some of the function will no longer be useful.**
+  - util.py - contains utility functions for vision to filter labels, get N most probably, normalize coordinates from vision, or wrap yaw. **Note that vision will be changed in future, some of the functions will no longer be useful.**
   - basic_states.py - contains all of the states for roulette and dice AI.
   - control_wrapper.py - wrapper made to ease communication with control system, making it easy to send basic commands such as dive, yaw, pitch, roll, move forward.
@@ Line 23: / Line 21: @@
   - SubscribeState.py - a state that was made which accept also topic to which you want to subscribe. It is also modified to pass over any input/output keys. **In future this file will also contain SynchronousSubscribeState that subscribes to two topics and moves once it has two**
-There is a useful tool to see state machine and transitions of it called **smach_viewer**. To run it, run
+There is a useful tool to see state machine and transitions of it called [[http://wiki.ros.org/smach_viewer|smach_viewer]]. To run it, run
 <code bash>
 rosrun smach_viewer smach_viewer.py
@@ Line 31: / Line 29: @@
 ===== Things to know when developing AI =====
   * When inheriting from **SubscribeState** instead of **SmachState**, you need to use **self.exit("outcome")** instead of **return "outcome"**
+  * Every python script that is going to run any state machine **must have** in its main function these lines of code below.
+<code python>
+while rospy.get_time() == 0:
+    continue
+</code>
   * Every time you create control_wrapper instance, you need to set depth value again.
   * If your state is using control wrapper to move, right before final outcome make sure to set changed yaw/roll/pitch/forward to 0.
   * Control wrapper forward and strafe do not use relative same way as yaw and pitch, use instead **strafeLeftError()** and **forwardError()**
-  * Some current AI files use parameters from roscore server for different configuration of values. They will crash if they do not load parameters. To load parameters run
+  * Some current AI files use parameters from roscore server for different configuration of values. They will crash if they do not load parameters. Parameters are located in <wrap em>/ros/robosub/param/</wrap> or some may be located in individual utility folders. To load parameters run
 <code bash>
 rosparam load [param_file_name].yaml
@@ Line 40: / Line 43: @@
   * Every time you restart roscore you need to reload parameters
   * Our vision detection requires undistortion to be running.
+===== Example Flow Chart =====
+<flow>
+graph LR;
+    A(SM_ROOT)-->|execute|B[START_SWITCH];
+    subgraph RoboSub
+    B-->C[GATE_TASK];
+    C-->D[PATH_MARKER_TASK1];
+    D-->E[DICE_TASK];
+    E-->F[PATH_MARKER_TASK2];
+    F-->G[GOTO_PINGER];
+    G-->H{Where am I?};
+    H-->|Roulette|I[ROULETTE_TASK];
+    H-->|Square|J[SQUARE_TASK];
+    end
+    I-->EN((end))
+    J-->EN((end))
+click B "start_switch"
+click C "gate_task"
+click D "path_marker_task"
+click E "dice_task"
+click F "path_marker_task"
+click G "goto_pinger"
+click I "roulette_task"
+click J "square_task"
+style A fill:#f9f,stroke:#333,stroke-width:2px;
+style EN fill:#f9f,stroke:#333,stroke-width:2px;
+</flow>

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