how to prevent navigate backwards, and only rotate and move forwards for navigation?

asked 2017-10-06 11:57:06 -0500

vcdanda
38 ●6 ●7 ●9

Hi, I'm using navigation stack and using teb_local_planner for path planning. But when I use it, I found there's problem for the robot because it will move backwards while my laser can only detect the forward area. Is there any parameter that I can adjust to make it only rotate and move forward?

I've searched on the website, someone said they change the min_vel to negative, and someone said to change the escape_vel to 0. I have no idea about these, and maybe other parameters I need to know in advance?

Anyone familiar with teb_local_planner? I'm glad to hear your advice. Thanks.

answered 2017-10-06 12:35:02 -0500

croesmann
2531 ●21 ●36 ●38

I assume you have a differential drive robot.

Unfortunately, we cannot restrict the optimzer's search space to positive velocities only, since our solver does not support hard-constraints. But you can penalize backwards motions by significantly increasing parameter weight_kinematics_forward_drive. Increase the value by using rqt_reconfigure until you find a satisfactory value (too large values might reduce convergence speed).

Furthermore, you can reduce max_vel_x_backwards to 0 (or it is better to reduce this paramter to at least the value of parameter penalty_epsilon from a numerical point of view; the value is 0.1 by default; I am going to improve this behavior in future versions).

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Never thought about this solution. Sounds pretty reasonable, I'll do as what you have said by changing these parameters . Hope I will get a good result.