planning: added exit condition for backup stage in sidepass.

modules/planning/conf/scenario_side_pass_config.pb.txt

@@ -11,6 +11,7 @@ side_pass_config: {
   approach_obstacle_min_stop_distance: 4.0
   block_obstacle_min_speed: 0.1
   enable_obstacle_blocked_check: true
+  max_backup_stage_cycle_num: 30
 }
 stage_config: {
   stage_type: SIDE_PASS_APPROACH_OBSTACLE

modules/planning/proto/planning_config.proto

@@ -74,6 +74,7 @@ message ScenarioSidePassConfig {
   optional double block_obstacle_min_speed = 4 [default = 0.1]; // m/s
   // set to false to work around large vehicle splitting issue in perception
   optional bool enable_obstacle_blocked_check = 5 [default = true];
+  optional uint32 max_backup_stage_cycle_num = 6 [default = 30];
 }
 
 message ScenarioStopSignUnprotectedConfig {

modules/planning/scenarios/side_pass/side_pass_scenario.h

@@ -36,6 +36,7 @@ struct SidePassContext {
   PathData path_data_;
   ScenarioSidePassConfig scenario_config_;
   int pass_obstacle_stuck_cycle_num_;
+  uint32_t backup_stage_cycle_num;
 };
 
 class SidePassScenario : public Scenario {

modules/planning/scenarios/side_pass/side_pass_stage.cc

@@ -90,7 +90,11 @@ Stage::StageStatus SidePassBackup::Process(
     break;
   }
 
-  if (!has_blocking_obstacle) {
+  GetContext()->backup_stage_cycle_num += 1;
+  if (!has_blocking_obstacle ||
+      GetContext()->backup_stage_cycle_num >
+          GetContext()->scenario_config_.max_backup_stage_cycle_num()) {
+    GetContext()->backup_stage_cycle_num = 0;
     next_stage_ = ScenarioConfig::NO_STAGE;
     return Stage::FINISHED;
   }
@@ -223,6 +227,7 @@ Stage::StageStatus SidePassGeneratePath::Process(
     const TrajectoryPoint& planning_start_point, Frame* frame) {
   if (!ExecuteTaskOnReferenceLine(planning_start_point, frame)) {
     AERROR << "Fail to plan on reference_line.";
+    GetContext()->backup_stage_cycle_num = 0;
     next_stage_ = ScenarioConfig::SIDE_PASS_BACKUP;
     return Stage::FINISHED;
   }