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Can movebase (navfn and base_local_planner) be used for ackermann steered robots!? ... and @ 2. what could the error: Failed to find a valid control. Even after executing recovery behaviors .... mean!?

pathplanning

asked 2014-03-30 13:08:29 -0500

moejoegoe
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I use the map server, a global and local plan is created and I also get cmd_vel outputs. This is a geometry_msgs/Twist output with a value linear.x for the speed and angular.z for the speed around the z-axis -> I generate a odom message from this message to simulate a input for the navigation stack... noticeable is that the value for the speed around the z-axis changes a lot, also from negative to positive values and back... and after some time I get this error!? I'm glad about any suggestions or help (I use ros hydro)

Best regards Matthias

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answered 2014-03-30 17:45:45 -0500

ahendrix

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The short answer is that navfn and base_local_planner aren't suitable for ackermann type robots. The planners don't take into account the kinematic constraints (minimum turning radius, can't turn in place) of the robot, and therefore can generate plans that aren't executable by the robot.

It is possible to use the sbpl_lattice_planner as the global planner, but there isn't a great local planner for ackermann type robots yet.

It's difficult to say what is wrong with your specific simulation without more details. It sounds like the local planner is failing to find a valid path, but without knowing the specifics of your configuration, it's hard to say whether that's a problem with your costmaps, with the local planner configuration, with how you're running the simulation, or something else entirely.

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Asked: 2014-03-30 13:08:29 -0500

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Last updated: Mar 30 '14

Can movebase (navfn and base_local_planner) be used for ackermann steered robots!? ... and @ 2. what could the error: Failed to find a valid control. Even after executing recovery behaviors .... mean!? edit

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Can movebase (navfn and base_local_planner) be used for ackermann steered robots!? ... and @ 2. what could the error: Failed to find a valid control. Even after executing recovery behaviors .... mean!?