pgm_map_creator

The ROS package pgm_map_creator can generate the pgm map directly from the Gazebo world. Compilation errors occur in ROS melodic are fixed. See reference for the original version of the package.

Environment

Ubuntu 18.04, ROS Melodic.

Installation

Install the dependencies.

sudo apt-get install libignition-math2-dev protobuf-compiler

Clone the package to the src folder.

cd catkin_ws/src/
git clone https://github.com/gene-su/pgm_map_creator

Build the catkin workspace.

cd catkin_ws
catkin_make

Usage

Copy the world file to the worlds folder.

cd catkin_ws/src/pgm_map_creator
mkdir worlds
cp my_world.world ~/catkin_ws/src/pgm_map_creator/worlds/

Add the plugin to the world file.

Add the following code to the my_world.world, just before the </world> tag.

<plugin filename="libcollision_map_creator.so" name="collision_map_creator"/>

roslaunch the node gazebo_ros to spwan the world file in the Gazebo.

cd catkin_ws/src/pgm_map_creator/launch
touch my_world.launch

my_world.launch

<?xml version="1.0" encoding="UTF-8"?>
<launch>
  <!-- World File -->
  <arg name="world_file" default="$(find pgm_map_creator)/worlds/my_world.world"/>

  <!-- Launch Gazebo World -->
  <include file="$(find gazebo_ros)/launch/empty_world.launch">
    <arg name="use_sim_time" value="true"/>
    <arg name="debug" value="false"/>
    <arg name="gui" value="true" />
    <arg name="world_name" value="$(arg world_file)"/>
  </include>
</launch>

roslaunch pgm_map_creator my_world.launch

roslaunch the node request_publisher to create the pgm map of the world file.

roslaunch pgm_map_creator request_publisher.launch

Wait for the plugin th generate map. Track the progess in the terminal that spawns the world file. Once it is done, the pgm map would be in the map folder of the pgm_map_creator.

Create the yaml file for the pgm map.

You may also need a yaml file which provides the metadata of the map.

cd catkin_ws/src/pgm_map_creator/maps
touch map.yaml

map.yaml

image: map.pgm
resolution: 0.01
origin: [-15.0, -15.0, 0.0]
occupied_thresh: 0.65
free_thresh: 0.196
negate: 0

The parameters resolution and origin are based on the arguments in request_publisher.launch.

Issues

1. error: ‘int_p_NULL’ was not declared in this scope

Add the following code to the top of /usr/include/boost/gil/extension/io/png_io_private.hpp

#define png_infopp_NULL (png_infopp)NULL
#define int_p_NULL (int*)NULL

2. [libprotobuf ERROR google/protobuf/descriptor_database.cc:57] File already exists in database: vector2d.proto

Change CmakeLists in pgm_map_creator/msgs/CMakeLists.txt to the following

find_package(Protobuf REQUIRED)

set(PROTOBUF_IMPORT_DIRS)
foreach(ITR ${GAZEBO_INCLUDE_DIRS})
  if(ITR MATCHES ".*gazebo-[0-9.]+$")
    set(PROTOBUF_IMPORT_DIRS "${ITR}/gazebo/msgs/proto")
  endif()
endforeach()

set (msgs
  collision_map_request.proto
  #${PROTOBUF_IMPORT_DIRS}/vector2d.proto
  #${PROTOBUF_IMPORT_DIRS}/header.proto
  #${PROTOBUF_IMPORT_DIRS}/time.proto
)

PROTOBUF_GENERATE_CPP(PROTO_SRCS PROTO_HDRS ${msgs})
add_library(collision_map_creator_msgs SHARED ${PROTO_SRCS})
target_include_directories(collision_map_creator_msgs PUBLIC ${PROTOBUF_INCLUDE_DIRS})
target_link_libraries(collision_map_creator_msgs ${PROTOBUF_LIBRARY})

3. Cropped Map

Edit the arguments in the launch/request_publisher.launch for a larger map size.

<arg name="xmin" default="-15" />
<arg name="xmax" default="15" />
<arg name="ymin" default="-15" />
<arg name="ymax" default="15" />
<arg name="scan_height" default="5" />
<arg name="resolution" default="0.01" />

Reference

1. Udacity: Robotic Software Engineer Nanodegree Program
2. https://github.com/udacity/pgm_map_creator
3. https://github.com/hyfan1116/pgm_map_creator