Pure Pursuit Controller

The Pure Pursuit Controller module calculates the steering angle for tracking a desired trajectory using the pure pursuit algorithm. This is used as a lateral controller plugin in the autoware_trajectory_follower_node.

Inputs

Set the following from the controller_node

• autoware_planning_msgs/Trajectory : reference trajectory to follow.
• nav_msgs/Odometry: current ego pose and velocity information

Outputs

Return LateralOutput which contains the following to the controller node

• autoware_control_msgs/Lateral: target steering angle
• LateralSyncData
  • steer angle convergence
• autoware_planning_msgs/Trajectory: predicted path for ego vehicle

Parameters

Name	Type	Description	Default	Range
ld_velocity_ratio	float	Velocity ratio for lookahead distance.	2.4	N/A
ld_lateral_error_ratio	float	Lateral error ratio for lookahead distance.	3.6	N/A
ld_curvature_ratio	float	Curvature ratio for lookahead distance.	120	N/A
long_ld_lateral_error_threshold	float	Threshold for lateral error in long lookahead distance.	0.5	N/A
min_lookahead_distance	float	Minimum lookahead distance.	4.35	N/A
max_lookahead_distance	float	Maximum lookahead distance.	15	N/A
converged_steer_rad	float	Steering angle considered as converged.	0.1	N/A
reverse_min_lookahead_distance	float	Minimum lookahead distance for reversing.	7	N/A
prediction_ds	float	Prediction step size.	0.3	N/A
prediction_distance_length	float	Prediction distance length.	21	N/A
resampling_ds	float	Resampling step size.	0.1	N/A
curvature_calculation_distance	float	Distance for curvature calculation.	4	N/A
enable_path_smoothing	boolean	Enable or disable path smoothing.	0	N/A
path_filter_moving_ave_num	float	Number of points for moving average path filter.	25	N/A
control_period	float	Control period.	0.03	N/A