ROS Answers: Open Source Q&A Forum - RSS feedhttps://answers.ros.org/questions/Open source question and answer forum written in Python and DjangoenROS Answers is licensed under Creative Commons Attribution 3.0Fri, 01 Feb 2019 09:17:50 -0600DWALocalPlanner very small theta velocitieshttps://answers.ros.org/question/314502/dwalocalplanner-very-small-theta-velocities/I am running DWALocalPlanner with these parameters:
DWAPlannerROS:
# Robot configuration parameters
acc_lim_x: 0.8
acc_lim_y: 0
acc_lim_theta: 0.8
max_vel_x: 0.3
min_vel_x: 0
max_vel_y: 0
min_vel_y: 0
holonomic_robot: false
max_vel_theta: 1.8
min_vel_theta: 0
max_trans_vel: 0.3
min_trans_vel: 0
max_rot_vel: 1.8
min_rot_vel: 1.2
# Goal Tolerance Parameters
yaw_goal_tolerance: 0.05
xy_goal_tolerance: 0.1
latch_xy_goal_tolerance: false
# Forward Simulation Parameters
sim_time: 4
vy_samples: 0
vx_samples: 20
vth_samples: 40
# Trajectory scoring parameters
path_distance_bias: 32.0
goal_distance_bias: 20.0
occdist_scale: 0.02
oscillation_reset_dist: 0.05
And the problem occurs sometimes when robot needs to rotate inplace in order to go to the goal. It gives very small velocity commands to angular.z and my robot simply cannot move as the velocity is very small. In fact, DWA gives like 0.2,0.4 rad/s whereas the minimum angular velocity that my robot can do is 1 rad/s (even if you think about it, 1 rad/s is pretty slow, needs 6 seconds for a full rotation).
I have tried to set min_vel_theta to 1.0 but in that case, robot simply cannot set angular velocity to 0.0.
Is there a solution or do I need to modify source code for that?Fri, 01 Feb 2019 09:17:50 -0600https://answers.ros.org/question/314502/dwalocalplanner-very-small-theta-velocities/