adding mppi path angle mode docs

configuration/packages/configuring-mppic.rst

@@ -620,6 +620,18 @@ Path Angle Critic
   Description
     Angular distance (rad) between robot and goal above which path angle cost starts being considered
 
+:mode:
+
+  ============== ===========================
+  Type           Default                    
+  -------------- ---------------------------
+  int            0
+  ============== ===========================
+
+  Description
+    Enum type for mode of operations for the path angle critic depending on path input types and behavioral desires. 0: Forward Preference, penalizes high path angles relative to the robot's orientation to incentivize turning towards the path. 1: No directional preference, penalizes high path angles relative to the robot's orientation or mirrored orientation (e.g. reverse), which ever is less, when a particular direction of travel is not preferable. 2: Consider feasible path orientation, when using a feasible path whereas the path points have orientation information (e.g. Smac Planners), consider the path's requested direction of travel to penalize path angles such that the robot will follow the path in the requested direction.
+
+
 Path Follow Critic
 ------------------
 
@@ -812,6 +824,7 @@ Example
             offset_from_furthest: 4
             threshold_to_consider: 0.5
             max_angle_to_furthest: 1.0
+            mode: 0
           # TwirlingCritic:
           #   enabled: true
           #   twirling_cost_power: 1

migration/Iron.rst

@@ -14,3 +14,12 @@ Changes to MPPI Goal Critic
 ***************************
 
 The MPPI Goal critic's formulation is changed to better keep up with speed on approach to goal instead of preemptively slowing too significantly. It also allows you to better use the weight to adjust the degree at which it slows more naturally. This change involves adjusting the ``threshold_to_consider`` to be the same as your prediction horizon (e.g. samples * dt * max speed) for both the goal critic and path follower critic to have a good hand-off between them without deceleration. 
+
+Changes to MPPI Path Angle Critic
+*********************************
+
+MPPI's Path Angle critic now has a ``mode`` setting to adjust behavior depending on robot's desired behavioral traits. Previously, it penalized path orientations that deviated far the the robot's forward orientation to turn the robot towards sharp changes in the path. This is still default (``mode: 0``), but other modes now exist too. 
+
+``mode: 1`` sets the penalization of path's relative directions by either forward orientation or the opposite for reversing to allow for true bidirectional motion when one way or another is not preferable for a symmetric robot. This uses only the path's relative points to the robot to decide which direction to incentivize. 
+
+``mode: 2`` instead uses the path's orientations when a feasible path is given from the Smac Planners or the Smoother server's algorithms. This way, the globally planned orientations are followed rather than the based solely on the path's relative points. This is useful for non-circular robots in highly confined settings where there may be restricted opportunities to change directions so following the global path's orientation are required to end in the orientation you require.