Prediction: narrow the range of caution in cruise

modules/prediction/common/prediction_gflags.cc

@@ -62,6 +62,8 @@ DEFINE_bool(enable_all_junction, false,
             "If consider all junction with junction_mlp_model.");
 DEFINE_double(caution_search_distance_ahead, 50.0,
               "The distance ahead to search caution-level obstacles");
+DEFINE_double(caution_search_distance_backward, 50.0,
+              "The distance backward to search caution-level obstacles");
 DEFINE_double(caution_search_distance_backward_for_merge, 60.0,
               "The distance backward to search caution-lebel obstacles "
               "in the case of merging");

modules/prediction/common/prediction_gflags.h

@@ -46,6 +46,7 @@ DECLARE_int32(road_graph_max_search_horizon);
 DECLARE_double(junction_distance_threshold);
 DECLARE_bool(enable_all_junction);
 DECLARE_double(caution_search_distance_ahead);
+DECLARE_double(caution_search_distance_backward);
 DECLARE_double(caution_search_distance_backward_for_merge);
 DECLARE_double(caution_search_distance_backward_for_overlap);
 DECLARE_double(caution_pedestrian_approach_time);

modules/prediction/scenario/prioritization/obstacles_prioritizer.cc

@@ -59,7 +59,8 @@ int NearestFrontObstacleIdOnLaneSequence(const LaneSequence& lane_sequence) {
   int nearest_front_obstacle_id = std::numeric_limits<int>::min();
   double smallest_relative_s = std::numeric_limits<double>::max();
   for (const auto& nearby_obs : lane_sequence.nearby_obstacle()) {
-    if (nearby_obs.s() < 0.0) {
+    if (nearby_obs.s() < 0.0 ||
+        nearby_obs.s() > FLAGS_caution_search_distance_ahead) {
       continue;
     }
     if (nearby_obs.s() < smallest_relative_s) {
@@ -74,7 +75,8 @@ int NearestBackwardObstacleIdOnLaneSequence(const LaneSequence& lane_sequence) {
   int nearest_backward_obstacle_id = std::numeric_limits<int>::min();
   double smallest_relative_s = std::numeric_limits<double>::max();
   for (const auto& nearby_obs : lane_sequence.nearby_obstacle()) {
-    if (nearby_obs.s() > 0.0) {
+    if (nearby_obs.s() > 0.0 ||
+        nearby_obs.s() < -FLAGS_caution_search_distance_backward) {
       continue;
     }
     if (-nearby_obs.s() < smallest_relative_s) {