Ask Your Question
0

teb_local_planner having difficulty making a 90 degree turn

asked 2020-10-22 05:10:40 -0500

darthShana gravatar image

updated 2020-10-22 05:15:37 -0500

HI All I have applied the teb_local_planner to my move_base for for my physical car like robot.. It reaches the goals i set successfully in my living room when just travelling in a straight line is required, or just soft turns are required to reach the goal pose

However when bigger turns are required the planner seems to abandon the initial feasible plan to make the turn and adopt more and more complex turn sequences, without giving the original plan a chance to work. It claims the trajectory is not feasible, but i dont understand why. I have a link to a youtube video of what happens

link to youtube

Im sure i have mis-configured it. But can anyonepoint me the direction what parameters i should be looking at? here is my base_local_planner_params.yaml

TebLocalPlannerROS:

  odom_topic: odom

    # Trajectory

  teb_autosize: True
  dt_ref: 0.3
  dt_hysteresis: 0.1
  max_samples: 500
  global_plan_overwrite_orientation: True
  allow_init_with_backwards_motion: True
  max_global_plan_lookahead_dist: 3.0
  global_plan_viapoint_sep: -1
  global_plan_prune_distance: 1
  exact_arc_length: False
  feasibility_check_no_poses: 2
  publish_feedback: True

    # Robot

  max_vel_x: 0.18
  max_vel_x_backwards: 0.18
  max_vel_y: 0.0
  max_vel_theta: 0.5 # the angular velocity is also bounded by min_turning_radius in case of a carlike robot (r = v / omega)
  acc_lim_x: 0.5
  acc_lim_theta: 0.7

  # ********************** Carlike robot parameters ********************
  min_turning_radius: 2.0        # Min turning radius of the carlike robot (compute value using a model or adjust with rqt_reconfigure manually)
  wheelbase: 0.3                 # Wheelbase of our robot
  cmd_angle_instead_rotvel: True # stage simulator takes the angle instead of the rotvel as input (twist message)
  # ********************************************************************

  footprint_model: # types: "point", "circular", "two_circles", "line", "polygon"
    type: "two_circles"
    radius: 0.2 # for type "circular"
    line_start: [0.0, 0.0] # for type "line"
    line_end: [0.4, 0.0] # for type "line"
    front_offset: 0.3 # for type "two_circles"
    front_radius: 0.2 # for type "two_circles"
    rear_offset: 0.0 # for type "two_circles"
    rear_radius: 0.2 # for type "two_circles"
    vertices: [ [0.25, -0.05], [0.18, -0.05], [0.18, -0.18], [-0.19, -0.18], [-0.25, 0], [-0.19, 0.18], [0.18, 0.18], [0.18, 0.05], [0.25, 0.05] ] # for type "polygon"

      # GoalTolerance

  xy_goal_tolerance: 0.4
  yaw_goal_tolerance: 0.25
  free_goal_vel: False
  complete_global_plan: True

    # Obstacles

  min_obstacle_dist: 0.27 # This value must also include our robot's expansion, since footprint_model is set to "line".
  inflation_dist: 0.1
  include_costmap_obstacles: True
  costmap_obstacles_behind_robot_dist: 1.0
  obstacle_poses_affected: 15

  dynamic_obstacle_inflation_dist: 0.6
  include_dynamic_obstacles: True

  costmap_converter_plugin: "costmap_converter::CostmapToLinesDBSRANSAC"
  costmap_converter_spin_thread: True
  costmap_converter_rate: 5

    # Optimization

  no_inner_iterations: 5
  no_outer_iterations: 4
  optimization_activate: True
  optimization_verbose: False
  penalty_epsilon: 0.1
  obstacle_cost_exponent: 4
  weight_max_vel_x: 2
  weight_max_vel_theta: 1
  weight_acc_lim_x: 1
  weight_acc_lim_theta: 1
  weight_kinematics_nh: 1000
  weight_kinematics_forward_drive: 1
  weight_kinematics_turning_radius: 1
  weight_optimaltime: 1 # must be > 0
  weight_shortest_path: 0
  weight_obstacle: 100
  weight_inflation: 0.2
  weight_dynamic_obstacle: 10 # not in use yet
  weight_dynamic_obstacle_inflation: 0.2
  weight_viapoint: 1
  weight_adapt_factor: 2

  # Homotopy Class Planner

  enable_homotopy_class_planning: True
  enable_multithreading: True
  max_number_classes: 4
  selection_cost_hysteresis: 1.0
  selection_prefer_initial_plan: 0.95
  selection_obst_cost_scale: 1.0
  selection_alternative_time_cost: False

  roadmap_graph_no_samples: 15
  roadmap_graph_area_width: 5
  roadmap_graph_area_length_scale: 1.0
  h_signature_prescaler: 0.5
  h_signature_threshold: 0.1
  obstacle_heading_threshold: 0.45
  switching_blocking_period: 0.0
  viapoints_all_candidates: True
  delete_detours_backwards: True
  max_ratio_detours_duration_best_duration: 3.0
  visualize_hc_graph: False
  visualize_with_time_as_z_axis_scale: False

  # Recovery

  shrink_horizon_backup: True
  shrink_horizon_min_duration ...
(more)
edit retag flag offensive close merge delete

2 Answers

Sort by ยป oldest newest most voted
1

answered 2020-11-14 08:46:54 -0500

tropic gravatar image

It looks like you are running SLAM at the same time as navigation. This is not always a good idea since it can mess up the paths the local planner i.e. TEB is trying to generate because

  1. the map area you are sending it to has unexplored areas and may be avoided by the planner because of cost
  2. the map is changing as the robot is moving and SLAM is running, which can instantiate a new local plan being generated.

Try running it with a static map and see if you still experience the same behavior.

TEB also requires a lot of tuning, here is one example of TEB running on an omni-directional mobile robot in a static map https://youtu.be/VfQWa06hQlM. It takes a lot of tuning, and it is hard to say it just one specific parameter. I can try and make one for a car-like robot and see how it behaves.

edit flag offensive delete link more
0

answered 2020-10-22 18:39:40 -0500

min_turning_radius: 2.0 is probably wrong. It indicates to the planner that your car is not able to make turns with a radius of less than two meters. I don't know how large your living room is, but I suspect your robot is small enough where its minimum turning radius is much less than that.

edit flag offensive delete link more

Your Answer

Please start posting anonymously - your entry will be published after you log in or create a new account.

Add Answer

Question Tools

Stats

Asked: 2020-10-22 05:10:40 -0500

Seen: 2,025 times

Last updated: Nov 14 '20