add：在基础地图上实现了实时避障以及实现了比较灵活的后撤，从而实现掉头

src/gc_navigation2_slamtoolbox/params/gc_navigation_slam.yaml

@@ -10,6 +10,8 @@ bt_navigator:
     odom_topic: /odom
     bt_loop_duration: 20
     default_server_timeout: 20
+    # 阿克曼底盘专用 BT：移除 Spin，恢复行为 = 清代价地图 → 后退 → 等待
+    default_nav_to_pose_bt_xml: /home/guoch/test_ws/install/gc_navigation2_slamtoolbox/share/gc_navigation2_slamtoolbox/config/nav_to_pose_ackermann.xml
     plugin_lib_names:
       - nav2_compute_path_to_pose_action_bt_node
       - nav2_compute_path_through_poses_action_bt_node
@@ -269,7 +271,7 @@ planner_server:
       analytic_expansion_ratio: 3.5
       analytic_expansion_max_length: 3.0
       minimum_turning_radius: 0.40
-      reverse_penalty: 2.0
+      reverse_penalty: 1.3     # 后退惩罚，越小越愿意后退（默认 2.0，设为 1.3 允许灵活倒车）
       change_penalty: 0.0
       non_straight_penalty: 1.2
       cost_penalty: 2.0
@@ -308,11 +310,13 @@ behavior_server:
     cycle_frequency: 10.0
     behavior_plugins: ["spin", "backup", "wait"]
     spin:
-      plugin: "nav2_behaviors/Spin"
+      plugin: "nav2_behaviors/Spin"    # 需保留以匹配默认 BT XML
     backup:
       plugin: "nav2_behaviors/BackUp"
+      backup_dist: 0.5
     wait:
       plugin: "nav2_behaviors/Wait"
+      wait_duration: 0.5
     global_frame: odom
     robot_base_frame: base_link
     transform_tolerance: 0.5