Perception: Added more debugging log

Perception: fixed type issue

Perception: fixed type issue2

modules/perception/lidar/lib/segmentation/cnnseg/cnn_segmentation.cc

@@ -342,6 +342,9 @@ void CNNSegmentation::GetObjectsFromSppEngine(
     num_foreground = spp_engine_.RemoveGroundPointsInForegroundCluster(
           original_cloud_, lidar_frame_ref_->roi_indices,
           lidar_frame_ref_->non_ground_indices);
+    if (num_foreground == 0) {
+      ADEBUG << "No foreground segmentation output";
+    }
   }
 
   const auto& clusters = spp_engine_.clusters();

modules/perception/lidar/lib/segmentation/cnnseg/spp_engine/spp_engine.cc

@@ -59,6 +59,10 @@ size_t SppEngine::ProcessConnectedComponentCluster(
   double sync_time1 = timer.toc(true);
   worker_.WakeUp();
   size_t num = detector_2d_cc_.Detect(&labels_2d_);
+  if (num == 0) {
+      ADEBUG << "No object detected";
+      // Later will decide if return this function here
+  }
   double detect_time = timer.toc(true);
   worker_.Join();
   double sync_time2 = timer.toc(true);