I’m working on Unitree Go2 using ROS 2 Foxy with the Nav2 navigation stack for autonomous multi-goal navigation.
The robot successfully navigates to the first 2D goal, but when I send a second or subsequent goal, several issues arise. Sometimes the robot fails just before reaching the goal, and in many cases, I need to restart map_navi.launch.py
to regain navigation functionality.
Additional critical observation:
- After the error occurs, the TF tree stops receiving updates.
- As a result, the URDF visualization in RViz turns completely white, indicating the robot model is no longer receiving pose or transform updates.
This makes multi-goal autonomous navigation completely unreliable.
This has become a critical problem for executing sequential navigation tasks. I’ve tried multiple fixes but the issue persists
Detailed Error Logs:
Navigation failures during or after first goal:
[bt_navigator-7] [ERROR] [1760002653.479168237] [bt_navigator]: Action server failed while executing action callback: "send_goal failed"
[bt_navigator-7] [WARN] [1760002653.479294512] [bt_navigator]: [navigate_to_pose] [ActionServer] Aborting handle.
[bt_navigator-7] [ERROR] [1760002695.737271274] [bt_navigator]: Action server failed while executing action callback: "send_goal failed"
[bt_navigator-7] [WARN] [1760002695.737376396] [bt_navigator]: [navigate_to_pose] [ActionServer] Aborting handle.
[controller_server-4] [WARN] Control loop missed its desired rate of 10.0000Hz
[controller_server-4] [WARN] Control loop missed its desired rate of 10.0000Hz
[controller_server-4] [WARN] Control loop missed its desired rate of 10.0000Hz
[controller_server-4] [ERROR] Failed to make progress
[controller_server-4] [WARN] [follow_path] [ActionServer] Aborting handle.
[amcl-2] [INFO] Message Filter dropping message: frame 'lidar_link' at time ... for reason 'Unknown'
[amcl-2] [WARN] Failed to transform initial pose in time (Lookup would require extrapolation into the future)
Observations:
- The first goal completes successfully.
- Errors typically occur when the robot reaches or is near the second goal.
- Control loop warnings indicate the
controller_server
cannot maintain its 10 Hz rate. - AMCL frequently drops messages or fails to transform the robot pose.
System Setup
- ROS 2 Distribution: Foxy
- Robot: Unitree Go2
- Navigation Stack: Nav2 with
DWBLocalPlanner
- Controller Frequency: 10 Hz
- Local Costmap: 6 x 6 m, resolution 0.05 m, update_frequency 2 Hz, publish_frequency 1 Hz
- Global Costmap: 50 x 50 m, resolution 0.05 m, update_frequency 0.5 Hz, publish_frequency 0.5 Hz
- Scan Topic:
/go2_unit_38798/scan
- Map Topic:
/go2_unit_38798/map
- Frames:
map → odom → base_link → lidar_link
- AMCL Parameters: max_particles=1000, min_particles=200, update_min_a=0.05, update_min_d=0.05, do_beamskip=false, laser_likelihood_max_dist=0.5
What I’ve Tried
- TF Verification
- Checked the TF tree (
map → odom → base_link → lidar_link
) withtf2_tools view_frames.py
. - Verified
odom
andbase_link
transforms are being published continuously.
- AMCL Tuning Attempts
- Adjusted
update_min_a
andupdate_min_d
to reduce excessive updates. - Monitored AMCL pose output; observed that it sometimes jumps to invalid positions after first goal.
- Controller / Planner Adjustments
- Experimented with increasing controller frequency.
- Modified
sim_time
, acceleration limits, and goal tolerances. - Verified
DWBLocalPlanner
configuration for velocity, acceleration, and trajectory evaluation.
- Costmap Management
- Cleared local and global costmaps before sending new goals.
- Observed local costmap updates occasionally lagging, possibly contributing to missed control loops.
- CPU / System Checks
- Monitored CPU usage; observed spikes during AMCL updates and local costmap publishing.
- Recovery / Restart
- After first goal fails, navigation only resumes after restarting
map_navi.launch.py
.
Also this is my nav2_map.yaml,
amcl:
ros__parameters:
use_sim_time: False
alpha1: 0.1 #0.2
alpha2: 0.2
alpha3: 0.15 #0.2
alpha4: 0.25 #0.2
alpha5: 0.3 #0.2
base_frame_id: "base_link"
beam_skip_distance: 0.5
beam_skip_error_threshold: 0.9
beam_skip_threshold: 0.3
do_beamskip: false
global_frame_id: "map"
lambda_short: 0.1
laser_likelihood_max_dist: 0.5 #2.0
laser_max_range: 100.0
laser_min_range: -1.0
laser_model_type: "likelihood_field"
max_beams: 120 #60
max_particles: 1000 #2000
min_particles: 200 #500
odom_frame_id: "odom"
pf_err: 0.01 #0.05
pf_z: 0.99
recovery_alpha_fast: 0.1 #0.0
recovery_alpha_slow: 0.001 #0.0
resample_interval: 1
robot_model_type: "omnidirectional"
save_pose_rate: 0.5
sigma_hit: 0.1 #0.2
tf_broadcast: true
transform_tolerance: 0.2 #1.0
update_min_a: 0.05 #0.2
update_min_d: 0.05 #0.25
z_hit: 0.9 #0.5
z_max: 0.03 #0.05
z_rand: 0.05 #0.5
z_short: 0.02 #0.05
scan_topic: /go2_unit_38798/scan #scan
set_initial_pose: true
initial_pose:
x: 0.0
y: 0.0
z: 0.0
yaw: 0.0 # radians, calculated from orientation z/w
amcl_map_client:
ros__parameters:
use_sim_time: False
amcl_rclcpp_node:
ros__parameters:
use_sim_time: False
bt_navigator:
ros__parameters:
use_sim_time: False
global_frame: map
robot_base_frame: base_link
odom_topic: /go2_unit_38798/odometry/filtered
default_bt_xml_filename: "navigate_w_replanning_and_recovery.xml"
plugin_lib_names:
- nav2_compute_path_to_pose_action_bt_node
- nav2_follow_path_action_bt_node
- nav2_back_up_action_bt_node
- nav2_spin_action_bt_node
- nav2_wait_action_bt_node
- nav2_clear_costmap_service_bt_node
- nav2_is_stuck_condition_bt_node
- nav2_goal_reached_condition_bt_node
- nav2_goal_updated_condition_bt_node
- nav2_initial_pose_received_condition_bt_node
- nav2_reinitialize_global_localization_service_bt_node
- nav2_rate_controller_bt_node
- nav2_distance_controller_bt_node
- nav2_speed_controller_bt_node
- nav2_recovery_node_bt_node
- nav2_pipeline_sequence_bt_node
- nav2_round_robin_node_bt_node
- nav2_transform_available_condition_bt_node
- nav2_time_expired_condition_bt_node
- nav2_distance_traveled_condition_bt_node
bt_navigator_rclcpp_node:
ros__parameters:
use_sim_time: False
controller_server:
ros__parameters:
use_sim_time: False
controller_frequency: 20.0
min_x_velocity_threshold: 0.001
min_y_velocity_threshold: 0.001
min_theta_velocity_threshold: 0.001
controller_plugins: ["FollowPath"]
# DWB parameters
FollowPath:
plugin: "dwb_core::DWBLocalPlanner"
debug_trajectory_details: True
min_vel_x: 0.0
min_vel_y: 0.0
max_vel_x: 0.3 #0.22
max_vel_y: 0.3 #0.22
max_vel_theta: 0.8 #0.5
min_speed_xy: 0.0 #0.12
max_speed_xy: 0.3 #0.12
min_speed_theta: 0.0
acc_lim_x: 2.5
acc_lim_y: 2.5 #1.0
acc_lim_theta: 3.2 #1.0
decel_lim_x: -2.5
decel_lim_y: -2.5
decel_lim_theta: -3.2
vx_samples: 20
vy_samples: 5
vtheta_samples: 20
sim_time: 1.5 #10.0
linear_granularity: 0.05
angular_granularity: 0.025
transform_tolerance: 0.2
xy_goal_tolerance: 0.25
trans_stopped_velocity: 0.25
short_circuit_trajectory_evaluation: True
stateful: True
critics: ["RotateToGoal", "Oscillation", "BaseObstacle", "GoalAlign", "PathAlign", "PathDist", "GoalDist"]
BaseObstacle.scale: 0.02
PathAlign.scale: 32.0
PathAlign.forward_point_distance: 0.1
GoalAlign.scale: 24.0
GoalAlign.forward_point_distance: 0.1
PathDist.scale: 32.0
GoalDist.scale: 24.0
RotateToGoal.scale: 32.0
RotateToGoal.slowing_factor: 5.0
RotateToGoal.lookahead_time: -1.0
controller_server_rclcpp_node:
ros__parameters:
use_sim_time: False
local_costmap:
local_costmap:
ros__parameters:
update_frequency: 10.0 #5.0
publish_frequency: 5.0 #2.0
global_frame: odom
robot_base_frame: base_link
use_sim_time: False
rolling_window: true
width: 6
height: 6
resolution: 0.05
footprint: '[[-0.4, -0.2], [-0.4, 0.2], [0.4, 0.2], [0.4, -0.2]]'
footprint_padding: 0.3
plugins: ["obstacle_layer", "inflation_layer"]
inflation_layer:
plugin: "nav2_costmap_2d::InflationLayer"
cost_scaling_factor: 3.0
inflation_radius: 0.4 #0.7
obstacle_layer:
plugin: "nav2_costmap_2d::ObstacleLayer"
enabled: True
observation_sources: scan
scan:
topic: /go2_unit_38798/scan #scan
max_obstacle_height: 2.0
clearing: True
marking: True
data_type: "LaserScan"
# voxel_layer:
# plugin: "nav2_costmap_2d::VoxelLayer"
# enabled: True
# publish_voxel_map: True
# origin_z: 0.0
# z_resolution: 0.05
# z_voxels: 16
# max_obstacle_height: 2.0
# mark_threshold: 0
# observation_sources: pointcloud
# pointcloud:
# topic: /utlidar/cloud_unused
# max_obstacle_height: 2.0
# clearing: True
# marking: True
# data_type: "PointCloud2"
static_layer:
map_subscribe_transient_local: True
always_send_full_costmap: True
local_costmap_client:
ros__parameters:
use_sim_time: False
local_costmap_rclcpp_node:
ros__parameters:
use_sim_time: False
global_costmap:
global_costmap:
ros__parameters:
update_frequency: 1.0
publish_frequency: 1.0
global_frame: map
robot_base_frame: base_link
use_sim_time: False
height: 50
width: 50
origin_x: -50.0
origin_y: -50.0
footprint: '[[-0.4, -0.2], [-0.4, 0.2], [0.4, 0.2], [0.4, -0.2]]'
resolution: 0.05
plugins: ["static_layer", "obstacle_layer", "inflation_layer"]
obstacle_layer:
plugin: "nav2_costmap_2d::ObstacleLayer"
enabled: True
observation_sources: scan
scan:
topic: /go2_unit_38798/scan #scan
max_obstacle_height: 2.0
clearing: True
marking: True
data_type: "LaserScan"
static_layer:
plugin: "nav2_costmap_2d::StaticLayer"
map_subscribe_transient_local: True
enabled: true
subscribe_to_updates: true
transform_tolerance: 0.5 #0.1
inflation_layer:
plugin: "nav2_costmap_2d::InflationLayer"
cost_scaling_factor: 3.0
inflation_radius: 0.5 #0.55
always_send_full_costmap: True
global_costmap_client:
ros__parameters:
use_sim_time: False
global_costmap_rclcpp_node:
ros__parameters:
use_sim_time: False
map_server:
ros__parameters:
frame_id: map
topic_name: map
use_sim_time: False
yaml_filename: "/home/unitree/qre_ws/src/mybotshop/go2_navigation/maps/custom_map.yaml"
map_saver:
ros__parameters:
use_sim_time: False
save_map_timeout: 5000
free_thresh_default: 0.25
occupied_thresh_default: 0.65
planner_server:
ros__parameters:
expected_planner_frequency: 20.0
use_sim_time: False
transform_tolerance: 1.0 # ADD THIS - allows 1 second tolerance
planner_plugins: ["GridBased"]
GridBased:
plugin: "nav2_navfn_planner/NavfnPlanner"
tolerance: 0.5
use_astar: false
allow_unknown: true
planner_server_rclcpp_node:
ros__parameters:
use_sim_time: False
recoveries_server:
ros__parameters:
costmap_topic: local_costmap/costmap_raw
footprint_topic: local_costmap/published_footprint
cycle_frequency: 10.0
recovery_plugins: ["spin", "backup", "wait"]
spin:
plugin: "nav2_recoveries/Spin"
backup:
plugin: "nav2_recoveries/BackUp"
wait:
plugin: "nav2_recoveries/Wait"
global_frame: odom
robot_base_frame: base_link
transform_timeout: 1.0
use_sim_time: False
simulate_ahead_time: 2.0
max_rotational_vel: 1.0
min_rotational_vel: 0.4
rotational_acc_lim: 3.2
robot_state_publisher:
ros__parameters:
use_sim_time: False
Questions / Support Needed
- Why does
bt_navigator send_goal failed
occur after the first goal? - Could the TF / AMCL errors be causing the
controller_server
to miss its control loop? - How should AMCL, DWB, and costmap parameters be tuned for multi-goal navigation on Unitree Go2?
- Are there best practices for ensuring stable AMCL transforms and TF timing in ROS 2 Foxy with high-frequency LiDAR?
Any help, parameter suggestions, or debugging guidance would be greatly appreciated.
Thanks in advance!
Minindu Pasan