Perception: add cropping point cloud and ground removal

modules/perception/common/perception_gflags.cc

@@ -52,6 +52,8 @@ DEFINE_double(normalizing_factor, 255,
 DEFINE_int32(num_point_feature, 5,
              "Length of raw point feature. Features include x, y, z,"
              "intensity and delta of time.");
+DEFINE_bool(enable_ground_removal, false, "Enable ground removal.");
+DEFINE_double(ground_removal_height, -1.5, "Height for ground removal.");
 DEFINE_bool(enable_downsample_beams, false,
             "Enable down sampling point cloud beams with a factor.");
 DEFINE_int32(downsample_beams_factor, 4,

modules/perception/common/perception_gflags.h

@@ -37,6 +37,8 @@ DECLARE_string(pfe_onnx_file);
 DECLARE_string(rpn_onnx_file);
 DECLARE_double(normalizing_factor);
 DECLARE_int32(num_point_feature);
+DECLARE_bool(enable_ground_removal);
+DECLARE_double(ground_removal_height);
 DECLARE_bool(enable_downsample_beams);
 DECLARE_int32(downsample_beams_factor);
 DECLARE_bool(enable_downsample_pointcloud);

modules/perception/lidar/lib/detection/lidar_point_pillars/point_pillars_detection.cc

@@ -28,6 +28,7 @@
 #include "modules/perception/common/perception_gflags.h"
 #include "modules/perception/lidar/common/lidar_timer.h"
 #include "modules/perception/lidar/common/pcl_util.h"
+#include "modules/perception/lidar/lib/detection/lidar_point_pillars/params.h"
 
 namespace apollo {
 namespace perception {
@@ -43,6 +44,18 @@ bool PointPillarsDetection::Init(const DetectionInitOptions& options) {
   point_pillars_ptr_.reset(new PointPillars(
       FLAGS_reproduce_result_mode, FLAGS_score_threshold,
       FLAGS_nms_overlap_threshold, FLAGS_pfe_onnx_file, FLAGS_rpn_onnx_file));
+
+  // point cloud range
+  x_min_ = Params::kMinXRange;
+  x_max_ = Params::kMaxXRange;
+  y_min_ = Params::kMinYRange;
+  y_max_ = Params::kMaxYRange;
+  z_min_ = Params::kMinZRange;
+  z_max_ = Params::kMaxZRange;
+  if (FLAGS_enable_ground_removal) {
+    z_min_ = std::max(z_min_, static_cast<float>(FLAGS_ground_removal_height));
+  }
+
   return true;
 }
 
@@ -88,7 +101,7 @@ bool PointPillarsDetection::Detect(const DetectionOptions& options,
                                   FLAGS_downsample_beams_factor)) {
       cur_cloud_ptr_ = downsample_beams_cloud_ptr;
     } else {
-      AWARN << "Down sample beams factor must be >= 1. Cancel down sampling."
+      AWARN << "Down-sample beams factor must be >= 1. Cancel down-sampling."
                " Current factor: "
             << FLAGS_downsample_beams_factor;
     }
@@ -202,11 +215,19 @@ void PointPillarsDetection::CloudToArray(const base::PointFCloudPtr& pc_ptr,
                                          const float normalizing_factor) {
   for (size_t i = 0; i < pc_ptr->size(); ++i) {
     const auto& point = pc_ptr->at(i);
-    out_points_array[i * FLAGS_num_point_feature + 0] = point.x;
-    out_points_array[i * FLAGS_num_point_feature + 1] = point.y;
-    out_points_array[i * FLAGS_num_point_feature + 2] = point.z;
+    float x = point.x;
+    float y = point.y;
+    float z = point.z;
+    float intensity = point.intensity;
+    if (z < z_min_ || z > z_max_ || y < y_min_ || y > y_max_ || x < x_min_ ||
+        x > x_max_) {
+      continue;
+    }
+    out_points_array[i * FLAGS_num_point_feature + 0] = x;
+    out_points_array[i * FLAGS_num_point_feature + 1] = y;
+    out_points_array[i * FLAGS_num_point_feature + 2] = z;
     out_points_array[i * FLAGS_num_point_feature + 3] =
-        point.intensity / normalizing_factor;
+        intensity / normalizing_factor;
     // delta of timestamp between prev and cur frames
     out_points_array[i * FLAGS_num_point_feature + 4] =
         static_cast<float>(pc_ptr->points_timestamp(i));

modules/perception/lidar/lib/detection/lidar_point_pillars/point_pillars_detection.h

@@ -74,6 +74,14 @@ class PointPillarsDetection {
   std::deque<base::PointDCloudPtr> prev_world_clouds_;
   base::PointFCloudPtr cur_cloud_ptr_;
 
+  // point cloud range
+  float x_min_;
+  float x_max_;
+  float y_min_;
+  float y_max_;
+  float z_min_;
+  float z_max_;
+
   // time statistics
   double downsample_time_ = 0.0;
   double fuse_time_ = 0.0;

modules/perception/production/conf/perception/perception_common.flag

@@ -88,12 +88,58 @@
 
 ###########################################################################
 # Flags from lidar_point_pillars
+
+# classification score threshold
+# type: double
+# default: 0.5
 --score_threshold=0.5
+
+# enable ground removal
+# type: bool
+# default: false
+--enable_ground_removal=false
+
+# remove point cloud that under this height
+# type: double
+# default: -1.5
+--ground_removal_height=-1.5
+
+# enable down-sample point cloud by beams
+# type: bool
+# default: false
 --enable_downsample_beams=false
+
+# factor for down-sampling point cloud beams
+# type: int
+# default: 4
 --downsample_beams_factor=4
+
+# enable down-sample point cloud by voxelization
+# type: bool
+# default: false
 --enable_downsample_pointcloud=false
+
+# down-sample voxel size along x-axis
+# type: double
+# default: 0.01
 --downsample_voxel_size_x=0.1
+
+# down-sample voxel size along y-axis
+# type: double
+# default: 0.01
 --downsample_voxel_size_y=0.1
+
+# down-sample voxel size along z-axis
+# type: double
+# default: 0.01
 --downsample_voxel_size_z=0.1
+
+# enable fusing point cloud of preceding frames
+# type: bool
+# default: false
 --enable_fuse_frames=false
+
+# number of frames (including current frame) for fusing point cloud
+# type: int
+# default: 5
 --num_fuse_frames=5