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[Move_base] problem of setting planner

Hi, everyone. I'm trying to use movebase package. However, my robot is not used differential wheels. Its steering and acceleration are actuated by servo motor and DC motor. movebase sent the cmdvel.linear.x and cmdvel.angular.z separately. But, my robot need to move and rotate together, like the car. It can't move like the planner's trajectory. I'm wondering how to set the planner.yaml to move as I wish. Appreciated for any suggestion or discussion, thanks.

controller_frequency: 3.0   # freq of update trace planning
recovery_behavior_enabled: true
clearing_rotation_allowed: false

TrajectoryPlannerROS:
   max_vel_x: 0.5  # miles / seconds
   min_vel_x: 0.1
   max_vel_y: 0.0  # zero for a differential drive robot
   min_vel_y: 0.0
   max_vel_theta: 1.0
   min_vel_theta: 0.4
   # min_in_place_vel_theta 0.4
   escape_vel: -0.1  # backward speed
   acc_lim_x: 1.5  # miles / senconds ^ 2
   acc_lim_y: 0.0  # zero for a differential drive robot
   acc_lim_theta: 0.5

   holonomic_robot: false
   yaw_goal_tolerance: 0.2 # about 6 degrees
   xy_goal_tolerance: 0.2  # 5 cm  # cannot smaller than map's revolution
   latch_xy_goal_tolerance: false
   pdist_scale: 0.4
   gdist_scale: 0.8
   meter_scoring: true

   heading_lookahead: 0.325
   heading_scoring: false
   heading_scoring_timestep: 0.8
   occdist_scale: 0.05
   oscillation_reset_dist: 0.05
   publish_cost_grid_pc: false
   prune_plan: true

   sim_time: 1.0
   sim_granularity: 0.05
   angular_sim_granularity: 0.1
   vx_samples: 8
   vy_samples: 0  # zero for a differential drive robot
   vtheta_samples: 20
   dwa: true
   simple_attractor: false

Asked by KSWang on 2019-03-15 05:22:43 UTC

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any one have some ideas? plz

Asked by KSWang on 2019-03-15 23:25:15 UTC

Answers

That kind of behavior is hard to achieve with the default TrajectoryPlannerROS. You should look into local planners that support car-like movement. For example you can check:
teb_local_planner and tutorials
sbpl_lattice_planner
This question also tackles the problem. More on Ackermann steering can be found here here.

Asked by pavel92 on 2019-03-19 03:41:50 UTC

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