Mobile Robot doesn't reach nav goal within goal tolerances in nav2
I have found no resources on this online (or I'm just that bad at searching) so I thought I could get this answered here.
I have a differential drive robot that I am simulating in nvidia's Isaac sim. I'm using the navigation2 stack in order for the mobile robot to navigate its surroundings and pick up objects within the environment. Everything works fine except for one minor detail.
I noticed in testing that the mobile robot does not completely reach the navigation goals that are set for it (i.e. the controller claims to have reached its goal when the base_frame of the robot fails to reach the set goal point).
Obviously this is generally fine and understandable since the controller must prevent the robot from oscillating around the goal point, but after checking positions several times I realized that the robot doesn't even reach the goal within the specified tolerance of the goal checker (currently set at 1mm).
Here is the navigation parameters file:
amcl:
ros__parameters:
use_sim_time: True
alpha1: 0.2
alpha2: 0.2
alpha3: 0.2
alpha4: 0.2
alpha5: 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: 2.0
laser_max_range: 100.0
laser_min_range: 0.4
laser_model_type: "likelihood_field"
max_beams: 60
max_particles: 2000
min_particles: 500
odom_frame_id: "odom"
pf_err: 0.05
pf_z: 0.99
recovery_alpha_fast: 0.0
recovery_alpha_slow: 0.0
resample_interval: 1
robot_model_type: "nav2_amcl::DifferentialMotionModel"
save_pose_rate: 0.5
sigma_hit: 0.2
tf_broadcast: true
transform_tolerance: 1.0
update_min_a: 0.2
update_min_d: 0.25
z_hit: 0.5
z_max: 0.05
z_rand: 0.5
z_short: 0.05
scan_topic: scan
map_topic: map
set_initial_pose: true
always_reset_initial_pose: false
first_map_only: false
initial_pose:
x: 0.0
y: 0.0
z: 0.0
yaw: 0.0
amcl_map_client:
ros__parameters:
use_sim_time: True
amcl_rclcpp_node:
ros__parameters:
use_sim_time: True
bt_navigator:
ros__parameters:
use_sim_time: True
global_frame: map
robot_base_frame: base_link
odom_topic: /odom
bt_loop_duration: 20
default_server_timeout: 40
# 'default_nav_through_poses_bt_xml' and 'default_nav_to_pose_bt_xml' are use defaults:
# nav2_bt_navigator/navigate_to_pose_w_replanning_and_recovery.xml
# nav2_bt_navigator/navigate_through_poses_w_replanning_and_recovery.xml
# They can be set here or via a RewrittenYaml remap from a parent launch file to Nav2.
plugin_lib_names:
- nav2_compute_path_to_pose_action_bt_node
- nav2_compute_path_through_poses_action_bt_node
- nav2_smooth_path_action_bt_node
- nav2_follow_path_action_bt_node
- nav2_spin_action_bt_node
- nav2_wait_action_bt_node
- nav2_back_up_action_bt_node
- nav2_drive_on_heading_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_globally_updated_goal_condition_bt_node
- nav2_is_path_valid_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_truncate_path_action_bt_node
- nav2_truncate_path_local_action_bt_node
- nav2_goal_updater_node_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_path_expiring_timer_condition
- nav2_distance_traveled_condition_bt_node
- nav2_single_trigger_bt_node
- nav2_is_battery_low_condition_bt_node
- nav2_navigate_through_poses_action_bt_node
- nav2_navigate_to_pose_action_bt_node
- nav2_remove_passed_goals_action_bt_node
- nav2_planner_selector_bt_node
- nav2_controller_selector_bt_node
- nav2_goal_checker_selector_bt_node
- nav2_controller_cancel_bt_node
- nav2_path_longer_on_approach_bt_node
- nav2_wait_cancel_bt_node
- nav2_spin_cancel_bt_node
- nav2_back_up_cancel_bt_node
- nav2_drive_on_heading_cancel_bt_node
bt_navigator_rclcpp_node:
ros__parameters:
use_sim_time: True
controller_server:
ros__parameters:
use_sim_time: True
controller_frequency: 20.0
min_x_velocity_threshold: 0.001
min_y_velocity_threshold: 0.5
min_theta_velocity_threshold: 0.001
failure_tolerance: 0.3
progress_checker_plugin: "progress_checker"
goal_checker_plugin: ["general_goal_checker"]
controller_plugins: ["FollowPath"]
# Progress checker parameters
progress_checker:
plugin: "nav2_controller::SimpleProgressChecker"
required_movement_radius: 0.5
movement_time_allowance: 10.0
# Goal checker parameters
general_goal_checker:
plugin: "nav2_controller::SimpleGoalChecker"
xy_goal_tolerance: 0.001
yaw_goal_tolerance: 0.001
stateful: true
FollowPath:
# Rotation Shim Controller parameters
plugin: "nav2_rotation_shim_controller::RotationShimController"
primary_controller: "nav2_mppi_controller::MPPIController"
angular_dist_threshold: 0.785
forward_sampling_distance: 2.0
rotate_to_heading_angular_vel: 1.8
max_angular_accel: 3.2
simulate_ahead_time: 1.0
# DWB parameters
time_steps: 56
model_dt: 0.05
batch_size: 2000
vx_std: 0.2
vy_std: 0.2
wz_std: 0.4
vx_max: 0.5
vx_min: -0.35
vy_max: 0.5
wz_max ...