🏉D.10 DWB Planner

သူ့က default controller ( default local planner ) ပဲ။

နမူနာ

controller_server:
  ros__parameters:
    # controller server parameters (see Controller Server for more info)
    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
    progress_checker_plugins: ["progress_checker"] # progress_checker_plugin: "progress_checker" For Humble and older
    goal_checker_plugins: ["goal_checker"]
    controller_plugins: ["FollowPath"]
    progress_checker:
      plugin: "nav2_controller::SimpleProgressChecker"
      required_movement_radius: 0.5
      movement_time_allowance: 10.0
    goal_checker:
      plugin: "nav2_controller::SimpleGoalChecker"
      xy_goal_tolerance: 0.25
      yaw_goal_tolerance: 0.25
      stateful: True
    # DWB controller parameters
    FollowPath:
      plugin: "dwb_core::DWBLocalPlanner"
      debug_trajectory_details: True
      min_vel_x: 0.0
      min_vel_y: 0.0
      max_vel_x: 0.26
      max_vel_y: 0.0
      max_vel_theta: 1.0
      min_speed_xy: 0.0
      max_speed_xy: 0.26
      min_speed_theta: 0.0
      acc_lim_x: 2.5
      acc_lim_y: 0.0
      acc_lim_theta: 3.2
      decel_lim_x: -2.5
      decel_lim_y: 0.0
      decel_lim_theta: -3.2
      vx_samples: 20
      vy_samples: 5
      vtheta_samples: 20
      sim_time: 1.7
      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
      GoalAlign.scale: 24.0
      PathAlign.forward_point_distance: 0.1
      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¶

• DWB Controller

• XYTheta Iterator

• Kinematic Parameters

• Publisher

DWB Controller

Name	Description	Type	Default
critics	list of critics plugins to use	vector<string>	N/A
default_critics_namespace	Namespaces of load critics in	vector<string>	["dwb_critics"]
prune_plan	Whether to prune the path of old, passed points. (လမ်းဟောင်း,ဖြတ်ခဲ့သောအမှတ်တွေကို ဖြတ်သွားချင်းရှိမရှိ )	bool	TRUE
shorten_transformed_plan	Determines whether we will pass the full plan on to the critics.	bool	TRUE
prune_distance	Distance (m) to prune backward until.	double	2.0
forward_prune_distance	Distance (m) to prune forward until. If set to -1, it will search the full path for the closest point, in the case of no replanning.	double	2.0
debug_trajectory_details	Publish debug information (on what topic???).	bool	FALSE
trajectory_generator_name	Trajectory generator plugin name.	string	“dwb_plugins:: StandardTrajectory Generator”
goal_checker_name	goal checker plugin name	string	"dwb_plugins:: SimpleGoalChecker”
transform_tolerance	TF transform tolerance (s)	double	0.1
short_circuit_trajectory_evaluation	Stop evaluating score after best score is found	bool	TRUE
path_distance_bias(Legacy)	Old version of PathAlign.scale, use that instead	double	N/A
goal_distance_bias(Legacy)	Old version of GoalAlign.scale, use that instead	double	N/A
occdist_scale(Legacy)	Old version of ObstacleFootprint.scale, use that instead	double	N/A
max_scaling_factor(Legacy)	Old version of ObstacleFootprint.max_scaling_factor, use that instead	double	N/A
scaling_speed(Legacy)	Old version of ObstacleFootprint.scaling_speed, use that instead	double	N/A
PathAlign.scale	Scale for path align critic, overriding local default.	double	32.0
GoalAlign.scale	Scale for goal align critic, overriding local default.	double	24.0
PathDist.scale	Scale for path distance critic, overriding local default.	double	32.0
GoalDist.scale	Scale for goal distance critic, overriding local default.	double	24.0

XYTheta Iterator

Name	Description	Type	Default
vx_samples	Number of velocity samples in the X velocity direction	int	20
vy_samples	Number of velocity samples in the Y velocity direction	int	5
vtheta_samples	Number of velocity samples in the angular velocity direction	int	20

Kinematic Parameters

Name	Description	Type	Default
max_val_theta	maximum angular velocity (rad/s)	double	0.0
min_speed_xy	minimum translation speed (m/s)	double	0.0
max_speed_xy	maximum translation speed (m/s)	double	0.0
min_speed_theta	minimum angular speed (rad/s)	double	0.0
min_vel_x	minimum velocity X (m/s)	double	0.0
min_vel_y	minimum velocity Y (m/s)	double	0.0
max_vel_x	maximum velocity X (m/s)	double	0.0
max_vel_y	maximum velocity Y (m/s)	double	0.0
acc_lim_x	maximum acceleration X (m/s^2)	double	0.0
acc_lim_y	maximum acceleration Y (m/s^2)	double	0.0
acc_lim_theta	maximum acceleration rotation (rad/s^2)	double	0.0
decel_lim_x	maximum deceleration X (m/s^2)	double	0.0
decel_lim_y	maximum deceleration Y (m/s^2)	double	0.0
decel_lim_theta	maximum deceleration rotation (rad/s^2)	double	0.0

Publisher

Name	Description	Type	Default
publish_evaluation	whether to publish the local plan evaluation	bool	TRUE
publish_global_plan	whether to publish the global plan	bool	TRUE
publish_transform_plan	whether to publish the global plan in the odometry frame	bool	TRUE
publish_local_plan	whether to publish the local planner's plan	bool	TRUE
publish_trajectories	whether to publish debug trajectories	bool	TRUE
publish_cost_grid_pc	whether to publish the cost grid	bool	FALSE
maker_lifetime	How long for the maker to remain	double	0.1

Plugins¶

The plugins listed below are inside the dwb_plugins namespace.

• LimitedAccelGenerator

• StandardTrajectoryGenerator

LimitedAccelGenerator

Name	Description	Type	Defalut
sim_time	Time to simulate ahead by (s)	double	1.7

StandardTrajectoryGenerator

Name	Description	Type	Defalut
sim_time	Time to simulate ahead by (s)	double	1.7
discretize_by_time	If true, forward simulate by time. If False, forward simulate by linear and angular granularity.	bool	FALSE
time_granularity	Time ahead to project	double	0.5
linear_granularity	Linear distance forward to project	double	0.5
angular_granularity	Angular distance to project	double	0.025
include_last_point	Whether to include the last pose in the trajectory	bool	TRUE

Trajectory Critics¶

The trajectory critics listed below are inside the dwb_critics namespace.

• BaseObstacleCritic

• GoalAlignCritic

• GoalDistCritic

• ObstacleFootprintCritic

• OscillationCritic

• PathAlignCritic

• PathDistCritic

• PreferForwardCritic

• RotateToGoalCritic

• TwirlingCritic

BasicObstacleCritic

Name	Description	Type	Default
sum_scores	Whether to allow for scores to be summed up.	bool	FALSE
scale	Weighed scale for critic.	double	1.0

GoalAlignCritic

Name	Description	Type	Default
forward_point_distance	Point in front of robot to look ahead to compute angular change from. ( angular ပြောင်းလဲမှုကို တွကိချက်ရန် robot ရှေ့သို့ ညွှန်းပါ)	double	0.325
aggregation_type	last, sum, or product combination methods.	string	"last"
scale	Weighed scale for critic.	double	1.0

GoalDistCritic

Name	Description	Type	Default
aggregation_type	last, sum, or product combination methods.	string	"last"
scale	Weighed scale for critic.	double	1.0

ObstacleFootprintCritic

Name	Description	Type	Default
sum_scores	Whether to allow for scores to be summed up.	bool	FALSE
scale	Weighed scale for critic.	double	1.0

OscillationCritic

Name	Description	Type	Default
oscillation_reset_dist	Minimum distance to move to reset oscillation watchdog (m). (oscillation reset လုပ်ရန်တွက် ရွေ့ရန် အနည်းဆုံး အကွာဝေး)	double	0.05
oscillation_reset_angle	Minimum angular distance to move to reset watchdog (rad).	double	0.05
oscillation_reset_time	Duration when a reset may be called. If -1, cannot be reset..	double	-1
x_only_threshold	Threshold to check in the X velocity direction.	double	0.05
scale	Weighed scale for critic.	double	1.0

PathAlignCritic

Name	Description	Type	Default
forward_point_distance	Point in front of robot to look ahead to compute angular change from. ( angular ပြောင်းလဲမှုကို တွကိချက်ရန် robot ရှေ့သို့ ညွှန်းပါ)	double	0.325
aggregation_type	last, sum, or product combination methods.	string	"last"
scale	Weighed scale for critic.	double	1.0

PathDistCritic

Name	Description	Type	Default
aggregation_type	last, sum, or product combination methods.	string	"last"
scale	Weighed scale for critic.	double	1.0

PreferForwardCritic

Name	Description	Type	Default
Penalty	penalty to apply the backward motion	double	1.0
strafe_x	Minimum X velocity before penalty.	double	0.1
strafe_theta	Minimum angular velocity before penalty	double	0.2
theta_scale	Weight for anuglar velocity component	double	10.0
scale	Weighed scale for critic.	double	1.0

RotateToGoalCritic

Name	Description	Type	Default
xy_goal_tolerance	Tolerance to meet goal completion criteria (m).	double	0.25
trans_stopped_velocity	Velocity below is considered to be stopped at tolerance met (rad/s).	double	0.25
.slowing_factor	Factor to slow robot motion by while rotating to goal.	double	5.0
lookahead_time	If > 0, amount of time to look forward for a collision for..	double	-1
scale	Weighed scale for critic.	double	1.0

TwirlingCritic

Name	Description	Type	Default
scale	Weighed scale for critic.	double	1.0