How to call a global planner from within a custom planner?
Problem (TL;DR)
I am trying to write a custom global planner that can alternate between the another global planner (here navfn), and a custom algorithm of my own. The errors I am getting suggest a linker error, but I could also be incorrectly calling and using the navfn code. I would appreciate it if someone with more knowledge than me could confirm whether my implementation is correct or not.
Problem (full)
As above. My repository, including all necessary .h, .cpp, .xml and CMakeList files is here. The code is largely based off the ROS tutorial on writing a custom planner. It seems that this method relies on writing overloaded versions of functions that move_base can call. I would like someone more knowledgeable than me to confirm that my implementation is correct, specifically:
The definition of the
navfnobject from the class definition in the custom sinusoid_path_planner.h file:navfn::NavfnROS* navfn_planner = NULL;The initalization of the
navfnclass from within my custom plannerinitalizefunction, as written in the sinusoid_path_planner.cpp filenavfn_planner = new navfn::NavfnROS(); navfn_planner->initialize(name, costmap_ros);Calling the
navfn::NavfnROS::makePlanfunction from within themakePlanfunction of my custom planner, again in sinusoid_path_planner.cpp:navfn_planner->makePlan(start, goal, plan);
I've seen several other questions from people trying to do something similar (1, 2, 3) , but so far I haven't found any working pre-existing code. So hopefully an answer to this question can help those people as well.
Relevant system information:
- OS: Ubuntu 14.04
- ROS version: Indigo Igloo
- PCL version: PCL 1.8
The code in my linked repository compiles on my system but fails with this error:
[ INFO] [1560163720.835616531, 3720.674000000]: Created global planner sinusoid_path_planner/GlobalPlanner
/opt/ros/indigo/lib/move_base/move_base: symbol lookup error: /home/matt/auxiliary_ros_repo/devel/lib//libsinusoid_path_planner.so: undefined symbol: _ZN5navfn8NavfnROSC1Ev
[move_base-1] process has died [pid 16479, exit code 127, cmd /opt/ros/indigo/lib/move_base/move_base odom:=odometry/filtered __name:=move_base __log:=/home/matt/.ros/log/28c5f010-8b68-11e9-a9ae-e8b1fc8ba78b/move_base-1.log].
log file: /home/matt/.ros/log/28c5f010-8b68-11e9-a9ae-e8b1fc8ba78b/move_base-1*.log
all processes on machine have died, roslaunch will exit
shutting down processing monitor...
... shutting down processing monitor complete
done
De-mangling the symbol name with c++filt indicates that this is failing at the navfn::NavfnROS::NavfnROS() call. The "missing symbol" error is usually a linker problem. But as I've said, my implementation could also be wrong, and I would greatly appreciate someone confirming if this is the case or not.
You'll need to show us your
CMakeLists.txt.Plugins need to link against the libraries from which they are (attempting to) import(ing) symbols.
Are you linking to the Navfn libraries?
Sorry, I linked my repo above, but didn't make it clear enough that this included all the necessary files like the CMakeList.txt file. When I explicitly link
navfnit just changes the nature of the error message, hence why I wanted to confirm that the way I am calling navfn is correct.Also, like I said there are some compatibility issues I am trying to work around, which are confounding the problem. But that needs to be discussed in its own question (which I will put up as soon as I can) as I want the focus of this question to be on whether the implementation of
navfnis correct or not. I feel like this should have been something clearly and explicitly addressed in the tutorial, and that there should be a standard way of initializing and calling planners like this. But I haven't found any documentation clearly explaining this, other than some allusions to being able to call a global planner as a standalone package.to what exactly?
Sorry, forgot to add the link to the separate question - which you've already found. I've edited this question to redirect as necessary.