autoware_simple_object_merger

This package can merge multiple topics of autoware_perception_msgs/msg/DetectedObject with low calculation cost.

Design

Background

Object_merger is mainly used for merge process with DetectedObjects. There are 2 characteristics in Object_merger. First, object_merger solve data association algorithm like Hungarian algorithm for matching problem, but it needs computational cost. Second, object_merger can handle only 2 DetectedObjects topics and cannot handle more than 2 topics in one node. To merge 6 DetectedObjects topics, 6 object_merger nodes need to stand for now.

Therefore, autoware_simple_object_merger aim to merge multiple DetectedObjects with low calculation cost. The package do not use data association algorithm to reduce the computational cost, and it can handle more than 2 topics in one node to prevent launching a large number of nodes.

Use case

• Multiple radar detection

autoware_simple_object_merger can be used for multiple radar detection. By combining them into one topic from multiple radar topics, the pipeline for faraway detection with radar can be simpler.

Limitation

• Sensor data drops and delay

Merged objects will not be published until all topic data is received when initializing. In addition, to care sensor data drops and delayed, this package has a parameter to judge timeout. When the latest time of the data of a topic is older than the timeout parameter, it is not merged for output objects. For now specification of this package, if all topic data is received at first and after that the data drops, and the merged objects are published without objects which is judged as timeout.The timeout parameter should be determined by sensor cycle time.

• Post-processing

Because this package does not have matching processing, there are overlapping objects depending on the input objects. So output objects can be used only when post-processing is used. For now, clustering processing can be used as post-processing.

Interface

Input

Input topics is defined by the parameter of input_topics (List[string]). The type of input topics is std::vector<autoware_perception_msgs/msg/DetectedObjects.msg>.

Output

• ~/output/objects (autoware_perception_msgs/msg/DetectedObjects.msg)
  • Merged objects combined from input topics.

Parameters

• update_rate_hz (double) [hz]
  • Default parameter: 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: “base_link”

This parameter is the header frame_id of the output topic. If output topics use for perception module, it should be set for “base_link”

• timeout_threshold (double) [s]
  • Default parameter: 0.1

This parameter is the threshold for timeout judgement. If the time difference between the first topic of input_topics and an input topic is exceeded to this parameter, then the objects of topic is not merged to output objects.

  for (size_t i = 0; i < input_topic_size; i++) {
    double time_diff = rclcpp::Time(objects_data_.at(i)->header.stamp).seconds() -
                       rclcpp::Time(objects_data_.at(0)->header.stamp).seconds();
    if (std::abs(time_diff) < node_param_.timeout_threshold) {
      // merge objects
    }
  }

• input_topics (List[string])
  • Default parameter: “[]”

This parameter is the name of input topics. For example, when this packages use for radar objects,

input_topics:
  [
    "/sensing/radar/front_center/detected_objects",
    "/sensing/radar/front_left/detected_objects",
    "/sensing/radar/rear_left/detected_objects",
    "/sensing/radar/rear_center/detected_objects",
    "/sensing/radar/rear_right/detected_objects",
    "/sensing/radar/front_right/detected_objects",
  ]

can be set in config yaml file. For now, the time difference is calculated by the header time between the first topic of input_topics and the input topics, so the most important objects to detect should be set in the first of input_topics list.

Changelog for package autoware_simple_object_merger

0.43.0 (2025-03-21)

• Merge remote-tracking branch 'origin/main' into chore/bump-version-0.43
• chore: rename from [autoware.universe]{.title-ref} to [autoware_universe]{.title-ref} (#10306)
• Contributors: Hayato Mizushima, Yutaka Kondo

0.42.0 (2025-03-03)

• Merge remote-tracking branch 'origin/main' into tmp/bot/bump_version_base
• feat(autoware_utils): replace autoware_universe_utils with autoware_utils (#10191)
• chore: refine maintainer list (#10110)
  • chore: remove Miura from maintainer

  * chore: add Taekjin-san to perception_utils package maintainer ---------

• Contributors: Fumiya Watanabe, Shunsuke Miura, 心刚

0.41.2 (2025-02-19)

• chore: bump version to 0.41.1 (#10088)
• Contributors: Ryohsuke Mitsudome

0.41.1 (2025-02-10)

0.41.0 (2025-01-29)

0.40.0 (2024-12-12)

• Revert "chore(package.xml): bump version to 0.39.0 (#9587)" This reverts commit c9f0f2688c57b0f657f5c1f28f036a970682e7f5.
• fix: fix ticket links in CHANGELOG.rst (#9588)
• chore(package.xml): bump version to 0.39.0 (#9587)
  • chore(package.xml): bump version to 0.39.0
  • fix: fix ticket links in CHANGELOG.rst

  * fix: remove unnecessary diff ---------Co-authored-by: Yutaka Kondo <<yutaka.kondo@youtalk.jp>>

• fix: fix ticket links in CHANGELOG.rst (#9588)
• 0.39.0
• update changelog
• fix: fix ticket links to point to https://github.com/autowarefoundation/autoware_universe (#9304)
• fix: fix ticket links to point to https://github.com/autowarefoundation/autoware_universe (#9304)
• chore(package.xml): bump version to 0.38.0 (#9266) (#9284)
  • unify package.xml version to 0.37.0
  • remove system_monitor/CHANGELOG.rst
  • add changelog

  * 0.38.0

• Contributors: Esteve Fernandez, Fumiya Watanabe, Ryohsuke Mitsudome, Yutaka Kondo

0.39.0 (2024-11-25)

• fix: fix ticket links to point to https://github.com/autowarefoundation/autoware_universe (#9304)
• fix: fix ticket links to point to https://github.com/autowarefoundation/autoware_universe (#9304)
• chore(package.xml): bump version to 0.38.0 (#9266) (#9284)
  • unify package.xml version to 0.37.0
  • remove system_monitor/CHANGELOG.rst
  • add changelog

  * 0.38.0

• Contributors: Esteve Fernandez, Yutaka Kondo

0.38.0 (2024-11-08)

• unify package.xml version to 0.37.0
• refactor(radar_tracks_msgs_converter, simple_object_merger, radar_tracks_noise_filter)!: add package name prefix of autoware_ (#8173)
  • refactor: rename radar_tracks_msgs_converter package to autoware_radar_tracks_msgs_converter
  • refactor: rename simple_object_merger package to autoware_simple_object_merger

  * refactor: rename sensing/radar_tracks_noise_filter to sensing/autoware_radar_tracks_noise_filter ---------

• Contributors: Taekjin LEE, Yutaka Kondo

0.26.0 (2024-04-03)