chore(radar_tracks_msgs_converter): fix README

perception/radar_tracks_msgs_converter/README.md

@@ -7,31 +7,15 @@ This package converts from [radar_msgs/msg/RadarTracks](https://github.com/ros-p
 
 ## Design
 
-### Input / Output
+### Background
 
-- Input
-  - `~/input/radar_objects` (radar_msgs/msg/RadarTracks.msg): Input radar topic
-  - `~/input/odometry` (nav_msgs/msg/Odometry.msg): Ego vehicle odometry topic
-- Output
-  - `~/output/radar_detected_objects` (autoware_auto_perception_msgs/msg/DetectedObject.idl): The topic converted to Autoware's message. This is used for radar sensor fusion detection and radar detection.
-  - `~/output/radar_tracked_objects` (autoware_auto_perception_msgs/msg/TrackedObject.idl): The topic converted to Autoware's message. This is used for tracking layer sensor fusion.
+Autoware uses [radar_msgs/msg/RadarTracks.msg](https://github.com/ros-perception/radar_msgs/blob/ros2/msg/RadarTracks.msg) as radar objects input data.
+To use radar objects data for Autoware perception module easily, `radar_tracks_msgs_converter` converts message type from `radar_msgs/msg/RadarTracks.msg` to `autoware_auto_perception_msgs/msg/DetectedObject`.
+In addition, because many detection module have an assumption on base_link frame, `radar_tracks_msgs_converter` provide the functions of transform frame_id.
 
-### Parameters
-
-- `update_rate_hz` (double): The update rate [hz].
-  - Default parameter is 20.0
-- `new_frame_id` (string): The header frame of the output topic.
-  - Default parameter is "base_link"
-- `use_twist_compensation` (bool): If the parameter is true, then the twist of the output objects' topic is compensated by ego vehicle motion.
-  - Default parameter is "true"
-- `use_twist_yaw_compensation` (bool): If the parameter is true, then the ego motion compensation will also consider yaw motion of the ego vehicle.
-  - Default parameter is "false"
-- `static_object_speed_threshold` (float): Specify the threshold for static object speed which determines the flag `is_stationary` [m/s].
-  - Default parameter is 1.0
-
-## Note
+### Note
 
-This package convert the label from `radar_msgs/msg/RadarTrack.msg` to Autoware label.
+`Radar_tracks_msgs_converter` converts the label from `radar_msgs/msg/RadarTrack.msg` to Autoware label.
 Label id is defined as below.
 
 |            | RadarTrack | Autoware |
@@ -45,6 +29,54 @@ Label id is defined as below.
 | BICYCLE    | 32006      | 6        |
 | PEDESTRIAN | 32007      | 7        |
 
-- [radar_msgs/msg/RadarTrack.msg](https://github.com/ros-perception/radar_msgs/blob/ros2/msg/RadarTrack.msg): additional vendor-specific classifications are permitted starting from 32000.
+Additional vendor-specific classifications are permitted starting from 32000 in [radar_msgs/msg/RadarTrack.msg](https://github.com/ros-perception/radar_msgs/blob/ros2/msg/RadarTrack.msg).
+Autoware objects label is defined in [ObjectClassification.idl](https://gitlab.com/autowarefoundation/autoware.auto/autoware_auto_msgs/-/blob/master/autoware_auto_perception_msgs/msg/ObjectClassification.idl)
+
+## Interface
+
+### Input
+
+- `~/input/radar_objects` (`radar_msgs/msg/RadarTracks.msg`)
+  - Input radar topic
+- `~/input/odometry` (`nav_msgs/msg/Odometry.msg`)
+  - Ego vehicle odometry topic
+
+### Output
+
+- `~/output/radar_detected_objects` (`autoware_auto_perception_msgs/msg/DetectedObject.idl`)
+  - DetectedObject topic converted to Autoware message.
+  - This is used for radar sensor fusion detection and radar detection.
+- `~/output/radar_tracked_objects` (`autoware_auto_perception_msgs/msg/TrackedObject.idl`)
+  - TrackedObject topic converted to Autoware message.
+  - This is used for tracking layer sensor fusion.
+
+### Parameters
+
+- `update_rate_hz` (double) [hz]
+  - Default parameter is 20.0
+
+This parameter is update rate for the `onTimer` function.
+This parameter should be same as the frame rate of input topics.
+
+- `new_frame_id` (string)
+  - Default parameter is "base_link"
+
+This parameter is the header frame_id of the output topic.
+
+- `use_twist_compensation` (bool)
+  - Default parameter is "true"
+
+This parameter is the flag to use the compensation to linear of ego vehicle's twist.
+If the parameter is true, then the twist of the output objects' topic is compensated by the ego vehicle linear motion.
+
+- `use_twist_yaw_compensation` (bool)
+  - Default parameter is "false"
+
+This parameter is the flag to use the compensation to yaw rotation of ego vehicle's twist.
+If the parameter is true, then the ego motion compensation will also consider yaw motion of the ego vehicle.
+
+- `static_object_speed_threshold` (float) [m/s]
+  - Default parameter is 1.0
 
-- [Autoware objects label](https://gitlab.com/autowarefoundation/autoware.auto/autoware_auto_msgs/-/blob/master/autoware_auto_perception_msgs/msg/ObjectClassification.idl)
+This parameter is the threshold to determine the flag `is_stationary`.
+If the velocity is lower than this parameter, the flag `is_stationary` of DetectedObject is set to `true` and dealt as a static object.