Road User Stop

Role

The road_user_stop module stops the ego vehicle when pedestrians, cyclists, or other road users are detected on or near the road within the ego's planned trajectory. This module ensures safe interaction with vulnerable road users by maintaining appropriate stopping distances and making decisions about when to stop versus when to continue driving.

Activation

This module is activated if the launch parameter launch_road_user_stop_module is set to true.

Parameters

Option Parameters

Name	Unit	Type	Description	Default value
suppress_sudden_stop	[-]	bool	Enable to suppress sudden stop	true

Stop Planning Parameters

Longitudinal Margin Parameters

Name	Unit	Type	Description	Default value
default_margin	[m]	double	Default longitudinal margin to obstacle	5.0
terminal_margin	[m]	double	Stop margin at the goal position	3.0
minimum_margin	[m]	double	Minimum stop margin for behavior decision	3.0

Opposing Traffic Parameters

Name	Unit	Type	Description	Default value
stop_margin	[m]	double	Ideal stop-margin from moving opposing obstacle when ego stops	10.0
max_negative_velocity	[m/s]	double	Maximum velocity of opposing traffic to consider stop planning	-0.1
min_velocity_for_stop_planning	[m/s]	double	Minimum velocity of ego to consider stop planning	2.77
effective_deceleration	[m/s^2]	double	Higher value brings final stop-margin closer to ideal value	4.0

General Stop Planning Parameters

Name	Unit	Type	Description	Default value
hold_stop_velocity_threshold	[m/s]	double	The maximum ego velocity to hold stopping	0.01
hold_stop_distance_threshold	[m]	double	The ego keeps stopping if distance to stop changes within threshold	0.3
limit_min_acc	[m/s^2]	double	Overwrite the deceleration limit (usually from common_param.yaml)	-2.5
sudden_object_acc_threshold	[m/s^2]	double	If stop achievable by smaller deceleration, not "sudden stop"	-1.0
sudden_object_dist_threshold	[m]	double	If stop distance is longer than this, not considered "sudden stop"	1000.0
abandon_to_stop	[-]	bool	Give up stopping when cannot avoid run over within decel limit	false

Stop on Curve Parameters

Name	Unit	Type	Description	Default value
enable_approaching	[-]	bool	Enable approaching behavior on curved paths	false
additional_stop_margin	[m]	double	Additional stop margin for obstacles on curves	3.0
min_stop_margin	[m]	double	Minimum stop margin on curves	6.0

Obstacle Filtering Parameters

Object Type Parameters

Name	Unit	Type	Description	Default value
pedestrian	[-]	bool	Enable detection of pedestrians	true
bicycle	[-]	bool	Enable detection of bicycles	true
motorcycle	[-]	bool	Enable detection of motorcycles	false
unknown	[-]	bool	Enable detection of unknown objects	false

General Filtering Parameters

Name	Unit	Type	Description	Default value
trajectory_lateral_margin	[m]	double	Lateral margin from ego trajectory to detect objects	1.0

Intersection Parameters

Name	Unit	Type	Description	Default value
exclude	[-]	bool	If true, exclude objects inside intersection lanelets from detection	false

Crosswalk Parameters

Name	Unit	Type	Description	Default value
exclude	[-]	bool	Exclude objects near crosswalks	true
margin	[m]	double	Margin distance from crosswalk	1.0

Opposing Traffic Detection Parameters

Name	Unit	Type	Description	Default value
enable	[-]	bool	Enable wrong-way object detection	true
angle_threshold	[deg]	double	Angle threshold for wrong-way detection	150.0
min_speed_threshold	[m/s]	double	Minimum speed for wrong-way detection	0.5

Temporal Filtering Parameters

Name	Unit	Type	Description	Default value
min_detection_duration	[s]	double	Minimum duration for object detection	0.1
lost_object_retention_duration	[s]	double	Duration to keep tracking objects after they are lost or exit the detection area	2.0
polygon_expansion_length	[m]	double	Distance to expand object polygon outward from centroid when object was previously inside detection area	0.5

Limitations

• If object tracking is lost for an extended period or object classification is misidentified, the module may not function properly and may fail to stop as expected