0321-ROS- with map navigation

Semantic model with static navigation map

Foreword

• Background model is a semantic map, but ROS-NAV need a grid map, so I want to change my ways
• Also needs to be done in line with P3AT comes with a map format ArMap map
• Re-set the cost of ROS-Nav global map configuration

reference

ros-mapserver
ArMap Map file format
Resize the static map
setup map yaml file
Aria Docs: Maps
ArMap file formats

Learning Content

ROS-MapServer

Map Format

• Multiple file jointly decided map data, the map YAML file metadata describing meta-data, graphics files with the same name YAML files, graphics files describing raster data

Image Format

• General grayscale image to create a map, a fatal obstacle to pure black and pure white for freedom control, intermediate gray value uncertain, but may be determined by a threshold value if it is recognized as an obstacle, the threshold value processing by the internal MapServer deal with
• Determining whether the pixel gray scale higher risk probability using the following formula: occ = (255 - color_avg) / 255.0, where color_avg is the 8-bit value that results from averaging over all channels
• The image is read by SDL_Image library, the library supported file is supported map image data including bmp, git, jpg, png, tif, etc.

yaml format

• yaml some technical parameters

image: testmap.png
# 使用相对或绝对路径
resolution: 0.1
# 分辨率 0.1m/pixel
origin: [0.0, 0.0, 0.0]
# 图像的左下角（边界）在地图中的坐标
occupied_thresh: 0.65
# 判断像素格是否为障碍的阈值
free_thresh: 0.196
# 判断是否为自由空间的阈值
negate: 0
# 一般情况下，黑色为障碍物，白色为自由空间
width:  20  # m   Don't forget to create a file with 2000 pixel width
height: 20  # m   Don't forget to create a file with 2000 pixel height

global_costmap.yaml

global_costmap:
   global_frame: /map
   robot_base_frame: /base_link
   update_frequency: 3.0
   publish_frequency: 0.0  # For a static global map, there is generally no need to continually publish it
   static_map: true        # This parameter and the next are always set to opposite values. The global map is usually static so we set static_map to true
   rolling_window: false   # The global map is generally not updated as the robot moves to we set this parameter to false
   resolution: 0.01
   transform_tolerance: 1.0
   map_type: costmap
   width:  20 # m   Don't forget to create a file with 2000 pixel width
   height: 20 # m   Don't forget to create a file with 2000 pixel width

Command Line

rosrun map_server map_server mymap.yaml

<!-- Run the map server -->
      <node name="map_server" pkg="map_server" type="map_server" args="/tmp/my_map_waalre.yaml" />

Arnap

format

• Because the temporary expect no semantic model into ArMap, so here is omitted

Use Mapper3 modify the map

• 添加forbidden line, forbidden area, home point, home area

ROS-Map generation

new map

• CAD display, the whole environment is 148876mmX117600mm, namely 148.876mX117.6m
• 则width=148.876; height=117.600
• Suggested amendments is an integer:
• Setting resolution = 0.05m / pixel
• 2977.52: 2352
• Picture pixels 2978: 2352
• Fixed dimensions: width: 148.9; height: 117.6

The new chart resolution increases

• Setting resolution = 0.1m / pixel
• 1488.76: 1176
• Pixels: 1489: 1176

Sim old map

• 1417.4cmX1187.9cm; 141.74mX118.79m
• width=141.74; height=118.79
• Repair is an integer:
• Setting resolution = 0.05m / pixel
• 2834.8: 2375.8
• Picture pixels 2835: 2376
• Revised dimensions: width: 141.75 height: 118.8

Old map yaml

image: 4F-sim.png
resolution: 0.050000
origin: [0, 0, 0]
negate: 0
occupied_thresh: 0.65 # 无关紧要
free_thresh: 0.196 # # 无关紧要

width: 141.75
height: 118.8

PS Retouching

• LV semantic map drawn low pixel, with PS amplified to the specified resolution
• Toolbar - image - the image size - the specified pixel - Resample Image: Bicubic smoother (applicable to expand)

  Note: Windows Paint program that comes with, you can modify the image resolution, but did not enlarge the existing pixel graphics, but simply extends the boundaries of the picture, making the graphics peripheral pixels are all white

Reconfigure ROS

global costmap

tf and message design

• In order to facilitate control map-> odom relationship, i.e. a global positioning robot, or decide not to use fake amcl AMCL
• If you are using amcl or fake amcl, you need to ROSARIA be modified to add move_to interface.
  • Use amcl does not make sense to draw a map of semantics, because it is too simple geometric elements, using the registration algorithm still a problem, SLAM algorithm to generate the map is much better compared to the details contained in the laser sensor are generated.
• ARIA finally decided to amend the publisher, the original zs_worldframe into / map.
  • Later I thought, if the change / map, then, proxy there are a lot of things about the coordinate system also needs to be changed, it should do so, the topic name changed mapserver sent directly into zsworld_frame. Solve OK!
• Take a look at fake_amcl be convenient positioning in RViz, the temporarily tf between zs_worldframe and odom to disabled, if the location is not convenient then to major changes in the code.