Add dynamic_obstacle_stop module (behavior_velocity_planner)

Signed-off-by: Maxime CLEMENT <[email protected]>

planning/behavior_velocity_dynamic_obstacle_stop_module/CMakeLists.txt

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+cmake_minimum_required(VERSION 3.14)
+project(behavior_velocity_dynamic_obstacle_stop_module)
+
+find_package(autoware_cmake REQUIRED)
+autoware_package()
+pluginlib_export_plugin_description_file(behavior_velocity_planner plugins.xml)
+
+ament_auto_add_library(${PROJECT_NAME} SHARED
+  DIRECTORY src
+)
+
+ament_auto_package(INSTALL_TO_SHARE config)

planning/behavior_velocity_dynamic_obstacle_stop_module/README.md

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+## Dynamic Obstacle Stop
+
+### Role
+
+`dynamic_obstacle_stop` is a module that stops the ego vehicle from entering the _immediate_ path of a dynamic object.
+
+The _immediate_ path of an object is the area that the object would traverse during a given time horizon, assuming constant velocity and heading.
+
+![rviz example](docs/dynamic_obstacle_stop_rviz.png)
+
+### Activation Timing
+
+This module is activated if the launch parameter `launch_dynamic_obstacle_stop_module` is set to true in the behavior planning launch file.
+
+### Inner-workings / Algorithms
+
+The module insert a stop point where the ego path collides with the immediate path of an object.
+The overall module flow can be summarized with the following 4 steps.
+
+1. Filter dynamic objects.
+2. Calculate immediate path rectangles of the dynamic objects.
+3. Find earliest collision where ego collides with an immediate path rectangle.
+4. Insert stop point before the collision.
+
+In addition to these 4 steps, 2 mechanisms are in place to make the stop point of this module more stable: an hysteresis and a decision duration buffer.
+
+The `hysteresis` parameter is used when a stop point was already being inserted in the previous iteration
+and it increases the range where dynamic objects are considered close enough to the ego path to be used by the module.
+
+The `decision_duration_buffer` parameter defines the duration when the module will keep inserted the previous stop point, even after no collisions were found.
+
+#### Filter dynamic objects
+
+![filtering example](docs/DynamicObstacleStop-Filtering.drawio.svg)
+
+An object is considered by the module only if it meets all of the following conditions:
+
+- it is a vehicle (pedestrians are ignored);
+- it is moving at a velocity higher than defined by the `minimum_object_velocity` parameter;
+- it is not too close to the current position of the ego vehicle;
+- it is close to the ego path.
+
+For the last condition,
+the object is considered close enough if its lateral distance from the ego path is less than the threshold parameter `minimum_object_distance_from_ego_path` plus half the width of ego and of the object (including the `extra_object_width` parameter).
+In addition, the value of the `hysteresis` parameter is added to the minimum distance if a stop point was inserted in the previous iteration.
+
+#### Calculate immediate path rectangles
+
+![Immediate paths example](docs/DynamicObstacleStop-ImmediatePaths.drawio.svg)
+
+For each considered object, a rectangle is created representing its _immediate_ path.
+The rectangle has the width of the object plus the `extra_object_width` parameter
+and its length is the current speed of the object multiplied by the `time_horizon`.
+
+#### Find earliest collision
+
+![Earliest collision example](docs/DynamicObstacleStop-Collision.drawio.svg)
+
+We build the ego path footprints as the set of ego footprint polygons projected on each path point.
+We then calculate the intersections between these ego path footprints and the previously calculated immediate path rectangles.
+An intersection is ignored if the object is not driving toward ego, i.e., the absolute angle between the object and the path point is larger than $\frac{3 \pi}{4}$.
+
+The collision point with the lowest arc length when projected on the ego path will be used to calculate the final stop point.
+
+#### Insert stop point
+
+![Stop point example](docs/DynamicObstacleStop-StopPoint.drawio.svg)
+
+Before inserting a stop point, we calculate the range of path arc lengths where it can be inserted.
+The minimum is calculated to satisfy the acceleration and jerk constraints of the vehicle.
+If a stop point was inserted in the previous iteration of the module, its arc length is used as the maximum.
+Finally,
+the stop point arc length is calculated to be the arc length of the previously found collision point minus the `stop_distance_buffer` and the ego vehicle longitudinal offset, clamped between the minimum and maximum values.
+
+### Module Parameters
+
+| Parameter                               | Type   | Description                                                                                |
+| --------------------------------------- | ------ | ------------------------------------------------------------------------------------------ |
+| `extra_object_width`                    | double | [m] extra width around detected objects                                                    |
+| `minimum_object_velocity`               | double | [m/s] objects with a velocity bellow this value are ignored                                |
+| `stop_distance_buffer`                  | double | [m] extra distance to add between the stop point and the collision point                   |
+| `time_horizon`                          | double | [s] time horizon used for collision checks                                                 |
+| `hysteresis`                            | double | [m] once a collision has been detected, this hysteresis is used on the collision detection |
+| `decision_duration_buffer`              | double | [s] duration between no collision being detected and the stop decision being cancelled     |
+| `minimum_object_distance_from_ego_path` | double | [m] minimum distance between the footprints of ego and an object to consider for collision |

planning/behavior_velocity_dynamic_obstacle_stop_module/config/dynamic_obstacle_stop.param.yaml

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+/**:
+  ros__parameters:
+    dynamic_obstacle_stop: # module to stop or before entering the immediate path of a moving object
+      extra_object_width: 1.0  # [m] extra width around detected objects
+      minimum_object_velocity: 0.5  # [m/s] objects with a velocity bellow this value are ignored
+      stop_distance_buffer: 0.5  # [m] extra distance to add between the stop point and the collision point
+      time_horizon: 5.0  # [s] time horizon used for collision checks
+      hysteresis: 1.0  # [m] once a collision has been detected, this hysteresis is used on the collision detection
+      decision_duration_buffer : 1.0  # [s] duration between no collision being detected and the stop decision being cancelled
+      minimum_object_distance_from_ego_path: 1.0  # [m] minimum distance between the footprints of ego and an object to consider for collision