[perception] apollo lidar obstacle detection messed up by a random shape object.

[ntutangyun]

Issue

Hi team,

Recently I've been trying Apollo's lidar perception module with LGSVL simulator. I've encountered the following case:

• when there is no random-shape obstacle added, the lidar perception works fine. (recording by cyber_recorder)
• when a random-shape obstacle added in front, the number of obstacles detected seemed to be messed up. (recording by cyber_recorder)

Here's a screenshot when one vehicle is detected correctly.

Here's a screenshot when two vehicles are detected correctly.

Here's one vehicle plus one random-shape obstacle, detected normally.

But when the second vehicle is spawned, without changing the rest, the lidar perception produces 5 obstacles in the result, which by right should be 3 obstacles.
Two additional "ghost" obstacles appeared, where one is directly below the Apollo car and the other one behind the random-shape obstacle.

Steps to reproduce

• build Apollo pre6 branch.
• start boostrap_lgsvl.sh
• configure in Dreamview
  • Setup mode: Mkz Lgsvl
  • Vehicle: Lincoln2017MKZ LGSVL
  • map: Borregas Ave
• download and save the recording files as xxx.rec
• cyber_recorder play -l -f xxx.rec

Configurations

Below is my dag file for lidar perception:

module_config {
  module_library : "/apollo/bazel-bin/modules/perception/onboard/component/libperception_component_lidar.so"

 components {
    class_name : "SegmentationComponent"
    config {
      name: "Velodyne128Segmentation"
      config_file_path: "/apollo/modules/perception/production/conf/perception/lidar/velodyne128_segmentation_conf_lgsvl.pb.txt"
      flag_file_path: "/apollo/modules/perception/production/conf/perception/perception_common.flag"
      readers {
          channel: "/apollo/sensor/lidar128/compensator/PointCloud2"
        }
    }
  }

  components {
    class_name : "RecognitionComponent"
    config {
      name: "RecognitionComponent"
      config_file_path: "/apollo/modules/perception/production/conf/perception/lidar/recognition_conf.pb.txt"
      readers {
          channel: "/perception/inner/SegmentationObjects"
        }
    }
  }

  components {
    class_name: "FusionComponent"
    config {
      name: "SensorFusion"
      config_file_path: "/apollo/modules/perception/production/conf/perception/fusion/fusion_component_conf.pb.txt"
      readers {
          channel: "/perception/inner/PrefusedObjects"
        }
    }
  }
}

Please let me know if any other resources are needed to verify this. Thanks.

[jeroldchen]

Please refer to #12073 .