improve readability

Signed-off-by: kyoichi-sugahara <kyoichi.sugahara@tier4.jp>

planning/behavior_path_planner/include/behavior_path_planner/utils/path_safety_checker/objects_filtering.hpp

@@ -55,25 +55,37 @@ PredictedObjects filterObjects(
   const std::shared_ptr<ObjectsFilteringParams> & params);
 
 /**
- * @brief Filter objects based on their velocity.
+ * @brief Filters objects based on their velocity.
  *
- * @param objects The predicted objects to filter.
- * @param lim_v Velocity limit for filtering.
- * @return PredictedObjects The filtered objects.
+ * Depending on the remove_above_threshold parameter, this function either removes objects with
+ * velocities above the given threshold or only keeps those objects. It uses the helper function
+ * filterObjectsByVelocity() to do the actual filtering.
+ *
+ * @param objects The objects to be filtered.
+ * @param velocity_threshold The velocity threshold for the filtering.
+ * @param remove_above_threshold If true, objects with velocities above the threshold are removed.
+ *                               If false, only objects with velocities above the threshold are
+ * kept.
+ * @return A new collection of objects that have been filtered according to the rules.
  */
 PredictedObjects filterObjectsByVelocity(
-  const PredictedObjects & objects, const double lim_v, const bool filter_dynamic_objects = true);
+  const PredictedObjects & objects, const double velocity_threshold,
+  const bool remove_above_threshold == true);
 
 /**
- * @brief Filter objects based on a velocity range.
+ * @brief Helper function to filter objects based on their velocity.
  *
- * @param objects The predicted objects to filter.
- * @param min_v Minimum velocity for filtering.
- * @param max_v Maximum velocity for filtering.
- * @return PredictedObjects The filtered objects.
+ * This function iterates over all objects and calculates their velocity norm. If the velocity norm
+ * is within the velocity_threshold and max_velocity range, the object is added to a new collection.
+ * This new collection is then returned.
+ *
+ * @param objects The objects to be filtered.
+ * @param velocity_threshold The minimum velocity for an object to be included in the output.
+ * @param max_velocity The maximum velocity for an object to be included in the output.
+ * @return A new collection of objects that have been filtered according to the rules.
  */
 PredictedObjects filterObjectsByVelocity(
-  const PredictedObjects & objects, double min_v, double max_v);
+  const PredictedObjects & objects, double velocity_threshold, double max_velocity);
 
 /**
  * @brief Filter objects based on their position relative to a current_pose.

planning/behavior_path_planner/src/utils/path_safety_checker/objects_filtering.cpp

@@ -52,25 +52,26 @@ PredictedObjects filterObjects(
 }
 
 PredictedObjects filterObjectsByVelocity(
-  const PredictedObjects & objects, double lim_v, const bool filter_dynamic_objects)
+  const PredictedObjects & objects, const double velocity_threshold,
+  const bool remove_above_threshold)
 {
   if (filter_dynamic_objects) {
-    return filterObjectsByVelocity(objects, -lim_v, lim_v);
+    return filterObjectsByVelocity(objects, -velocity_threshold, velocity_threshold);
   } else {
-    return filterObjectsByVelocity(objects, lim_v, std::numeric_limits<double>::max());
+    return filterObjectsByVelocity(objects, velocity_threshold, std::numeric_limits<double>::max());
   }
 }
 
 PredictedObjects filterObjectsByVelocity(
-  const PredictedObjects & objects, double min_v, double max_v)
+  const PredictedObjects & objects, double velocity_threshold, double max_velocity)
 {
   PredictedObjects filtered;
   filtered.header = objects.header;
   for (const auto & obj : objects.objects) {
     const auto v_norm = std::hypot(
       obj.kinematics.initial_twist_with_covariance.twist.linear.x,
       obj.kinematics.initial_twist_with_covariance.twist.linear.y);
-    if (min_v < v_norm && v_norm < max_v) {
+    if (velocity_threshold < v_norm && v_norm < max_velocity) {
       filtered.objects.push_back(obj);
     }
   }