OMPL planner creates only a small number of states in roadmap/graph

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Uli_v
Posts: 29
Joined: 14 Dec 2018, 18:07

OMPL planner creates only a small number of states in roadmap/graph

Post by Uli_v » 28 Jan 2019, 23:02

Hi,

I am sharing the following scene (3DoFHolonomicPathPlanning demo modified to use PRMstar with 10 seconds planning time):
https://drive.google.com/open?id=1JFzqd ... 2g5HjfgoW0

I have added some debug information (e.g. number of total collision checks and number of collisions)

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Info:    PRMstar: Space information setup was not yet called. Calling now.
Info:    PRMstar: Optimization objective specified.
Info:    PRMstar: Starting planning with 2 states already in datastructure
Info:    PRMstar: Created 1394 states
Info:    PRMstar: bestCost_: 4.640044
ob::PlannerStatus solved = task->planner->solve(in->maxTime) took 10035ms
Collision check count 166114
In collision check count 13369
The number of created states of 1400 in 10 seconds seems to be low.

In my application, where I plan in 3D+1D rotation for a path of the gripper to a goal config, the planner creates even fewer states:
About 300 states in 10 seconds. It is probably lower, because the collision checking is slower (about 55k in 10 seconds). But in my case only about 2.4% of states are in collision (1337/55k=2.4%).

I am in contact with one of the OMPL lead developer for advice and he finds it strange, that only so few states are created. He suggested to update V-REP to use the latest OMPL version with V-REP (1.4.2). Currently V-REP uses 1.1.0 (I believe).

If I try to compile the V-REP plugin for OMPL 1.4.2, I get the following error. It was able to recompile V-REP plugin with OMPL 1.1.0 (but not 1.4.2):

Code: Select all

Scanning dependencies of target v_repExtOMPL
[ 33%] Building CXX object CMakeFiles/v_repExtOMPL.dir/plugin.cpp.o
In file included from /usr/local/include/ompl/base/StateSpace.h:43:0,
                 from /usr/local/include/ompl/base/SpaceInformation.h:43,
                 from /usr/local/include/ompl/base/Goal.h:41,
                 from /home/uli/Software/V-REP_OMPL_plugin_1.4.2/v_repExtOMPL/plugin.cpp:7:
/usr/local/include/ompl/base/ProjectionEvaluator.h:49:22: fatal error: Eigen/Core: No such file or directory
compilation terminated.

Thank you.

coppelia
Site Admin
Posts: 7159
Joined: 14 Dec 2012, 00:25

Re: OMPL planner creates only a small number of states in roadmap/graph

Post by coppelia » 29 Jan 2019, 14:14

Hello,

next V-REP release will use the newest OMPL sources.
You need to install Eigen (sudo apt install libeigen3-dev), and compile similar to:

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export CXXFLAGS=-isystem\ /usr/include/eigen3/ #or wherever it is located
cmake -DOMPL_LIBRARY=/home/user/Documents/ompl-1.4.2-Source/build/lib/libompl.so -DOMPL_INCLUDE_DIRS=/home/user/Documents/ompl-1.4.2-Source/src/ ..
cmake --build .
Cheers

Uli_v
Posts: 29
Joined: 14 Dec 2018, 18:07

Re: OMPL planner creates only a small number of states in roadmap/graph

Post by Uli_v » 29 Jan 2019, 16:20

Remember to fix the following issue related to OMPL when updating V-REP with the newest OMPL version:
viewtopic.php?f=5&t=7642&p=29929#p29929

Could you also add support for SO2 and SO3 in the plugin? Similar to this issue:
viewtopic.php?f=9&t=7693

Thank you.

Uli_v
Posts: 29
Joined: 14 Dec 2018, 18:07

Re: OMPL planner creates only a small number of states in roadmap/graph

Post by Uli_v » 29 Jan 2019, 16:49

Thanks for the help with the eigen3 issue. OMPL plugin with OMPL 1.4.2 is compiling now. But I needed to change the lines to compile (e.g. add "Release" in the path, and use unly a single "." at the end). See below

Code: Select all

export CXXFLAGS=-isystem\ /usr/include/eigen3/ #or wherever it is located
cmake -DOMPL_LIBRARY=/home/user/Documents/ompl-1.4.2-Source/build/Release/lib/libompl.so -DOMPL_INCLUDE_DIRS=/home/user/Documents/ompl-1.4.2-Source/src/ .
cmake --build .
With OMPL 1.4.2 it still creates only about 1300 states for the example when planning for 10 seconds.

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