Difference between revisions of "ROS2"

Revision as of 15:19, 7 December 2018

About

Use ROS2 in Elphel single or multi-camera systems. The cameras are 10393 system boards based on Xilinx Zynq, ARM.

Goals

Notes:

Having ROS2 cross-compiled and installed on each camera:

• Initialize cameras in a pre-defined multi-camera system - sync and sequence critical init
• Control multiple cameras from any camera of the system - parameters, recording
• Control multiple cameras from a PC (with ROS2 for PC installed).
• Control multiple cameras from a network device (w/o ROS2 installed, but with a browser) - by accessing a web server running on a camera interfaced with ROS2 of the camera. Can use nodejs or just lighttpd+php.

Status

Development

Interfaces

ROS2 nodes communicate over:

• 1 GigE LAN or (possibly) wifi (camera1-camera2..N, pc-camera1..N, pc1-pc2..M)
• within a single device

Notes:

ROS2 on Zynq

Installation

• For Embedded Linux (but not Ubuntu Distro) use meta-ros.git. What about meta-ros2?

TODO: Include meta-ros.git in elphel393 build system.

Include meta-ros to elphel393

• Add path to bblayers.conf
• Add to "IMAGE_INSTALL_append" of core-image-elphel393.bb:

packagegroup-ros2-world \

Workflow

ROS2 on PC

Installation

• Google and follow the general instructions.

Notes:

• apt install ros-bouncy-desktop available in 18.04, n/a in 16.04
• apt install ros-ardent-desktop available in 16.04

Workflow

• ROS2 will get installed to /opt/ros/<name>, <name> = ardent, bouncy.
• Terminal setup:

source /opt/ros/bouncy/setup.bash
or
source /opt/ros/bouncy/local_setup.bash

• Create a workspace
• Create some packages inside or clone - they have a vcs tool to clone all repos from a text file.
• Install colcon
• Then build with colcon
• Packages will not get installed to /opt/ros/bouncy/... Instead they will stay in their folders.
• To use a package:

source /opt/ros/bouncy/setup.bash
source ~/ros2_ws/some-package/install/local_setup.bash
ros2 pkg list
then run anything in this terminal

• Python scripts can live anywhere - just run them from that sourced terminal
• Good book about UDP?

ROS2 General Notes

Notes

• SROS is Secure ROS or something

Useful links

• Tutorials ErleRobotics
• Intel RealSense
• Ament tutorial - will not work for PC because it's outdated, will work in Yocto
• Colcon tutorial - this one worked for PC
• STD-SRVS discussion & ROS2 examples(?)
• About meta-ros

Docker

docker pull osrf/ros2:bouncy-desktop
docker run -i -t osrf/ros2:bouncy-desktop 
...no network, no colcon, no ament...

ROS2 on Zynq

Cross-compiled and installed in Yocto

Other links

• ROS on DDS

... 
if you are concerned about latency, like for soft real-time, you can basically tune DDS to be just a UDP blaster. In another scenario you might need something that behaves like TCP, but needs to be more 
tolerant to long dropouts, and with DDS all of these things can be controlled by changing the QoS parameters.
...

• FastRTPS benchmarks
• FastRTPS max message size
• Request-Response is done with service. Format srv

Work

Available packages

• SSH session:

root@elphel393:~# export AMENT_PREFIX_PATH=/usr
root@elphel393:~# ros2 pkg list
builtin_interfaces
demo_nodes_cpp
example_interfaces
geometry_msgs
rcl
rcl_interfaces
rclcpp
rclpy
rcutils
rmw
rmw_fastrtps_cpp
rosidl_cmake
rosidl_generator_c
rosidl_generator_cpp
rosidl_parser
rosidl_typesupport_interface
rosidl_typesupport_introspection_c
rosidl_typesupport_introspection_cpp
sensor_msgs

Test Talker and Listener

• SSH session 1:

root@elphel393:~# export AMENT_PREFIX_PATH=/usr
root@elphel393:~# ros2 run demo_nodes_cpp talker

• SSH session 2:

root@elphel393:~# export AMENT_PREFIX_PATH=/usr
root@elphel393:~# ros2 run demo_nodes_cpp listener

Notes:

• It populates /usr/lib/python3.5/site-packages/ so python scripts can be pretty much standalone
• If AMENT_PREFIX_PATH is not set (only for command line apps) then:

Traceback (most recent call last):
  File "/usr/bin/ros2", line 11, in <module>
    load_entry_point('ros2cli==0.4.0', 'console_scripts', 'ros2')()
  File "/usr/lib/python3.5/site-packages/ros2cli/cli.py", line 64, in main
    rc = extension.main(parser=parser, args=args)
  File "/usr/lib/python3.5/site-packages/ros2run/command/run.py", line 59, in main
    executable_name=args.executable_name)
  File "/usr/lib/python3.5/site-packages/ros2run/api/__init__.py", line 30, in get_executable_path
    paths = get_executable_paths(package_name=package_name)
  File "/usr/lib/python3.5/site-packages/ros2pkg/api/__init__.py", line 41, in get_executable_paths
    prefix_path = get_prefix_path(package_name)
  File "/usr/lib/python3.5/site-packages/ros2pkg/api/__init__.py", line 34, in get_prefix_path
    prefix_path = get_package_prefix(package_name)
  File "/usr/lib/python3.5/site-packages/ament_index_python/packages.py", line 49, in get_package_prefix
    content, package_prefix = get_resource('packages', package_name)
  File "/usr/lib/python3.5/site-packages/ament_index_python/resources.py", line 37, in get_resource
    for path in get_search_paths():
  File "/usr/lib/python3.5/site-packages/ament_index_python/search_paths.py", line 30, in get_search_paths
    "Environment variable '{}' is not set or empty".format(AMENT_PREFIX_PATH_ENV_VAR))
OSError: Environment variable 'AMENT_PREFIX_PATH' is not set or empty

ROS1

Build

Won't build

Build Configuration:
BB_VERSION           = "1.37.0"
BUILD_SYS            = "x86_64-linux"
NATIVELSBSTRING      = "universal"
TARGET_SYS           = "arm-poky-linux-gnueabi"
MACHINE              = "elphel393"
DISTRO               = "poky"
DISTRO_VERSION       = "2.4+snapshot-20181204"
TUNE_FEATURES        = "arm armv7a vfp neon cortexa9"
TARGET_FPU           = "softfp"
meta                 
meta-poky            
meta-yocto-bsp       = "HEAD:72867393fe2004ab9f0ee23eb09a975c82938b9e"
meta-ezynq           = "rocko:046de13c06cc248b725cb7b9928f35d4a369b50f"
meta-elphel393       = "rocko:0cea9b9b8776f0fe725316f1be1501396c95feb4"
meta-ros             = "HEAD:72068b17e4192b51e09c8dc633805a35edac8701"
meta-xilinx-bsp      = "HEAD:a18947c20dba2c0c38db8bde1ad4684995df4bbd"
meta-oe              
meta-python          
meta-networking      
meta-webserver       = "HEAD:34aa4c3202b427f59f843dc43a4e1afda4f81d13"

• Error 1:
  • ROS_USE_PYTHON3 = "yes"
  • IMAGE_INSTALL += "roslaunch"

NOTE: Resolving any missing task queue dependencies
ERROR: Nothing RPROVIDES 'python3-pycrypto' (but /home/oleg/GIT/elphel393_rocko_clean_install/meta/meta-ros/recipes-devtools/python/python3-paramiko_1.16.0.bb RDEPENDS on or otherwise requires it)
NOTE: Runtime target 'python3-pycrypto' is unbuildable, removing...
Missing or unbuildable dependency chain was: ['python3-pycrypto']
NOTE: Runtime target 'python3-paramiko' is unbuildable, removing...
Missing or unbuildable dependency chain was: ['python3-paramiko', 'python3-pycrypto']
NOTE: Runtime target 'roslaunch' is unbuildable, removing...
Missing or unbuildable dependency chain was: ['roslaunch', 'python3-paramiko', 'python3-pycrypto']
ERROR: Required build target 'core-image-elphel393' has no buildable providers.
Missing or unbuildable dependency chain was: ['core-image-elphel393', 'roslaunch', 'python3-paramiko', 'python3-pycrypto']

• Successful build:
  • IMAGE_INSTALL += "roslaunch"

NOTE: Resolving any missing task queue dependencies
ERROR: Nothing RPROVIDES 'python3-pycrypto' (but /home/oleg/GIT/elphel393_rocko_clean_install/meta/meta-ros/recipes-devtools/python/python3-paramiko_1.16.0.bb RDEPENDS on or otherwise requires it)
NOTE: Runtime target 'python3-pycrypto' is unbuildable, removing...
Missing or unbuildable dependency chain was: ['python3-pycrypto']
NOTE: Runtime target 'python3-paramiko' is unbuildable, removing...
Missing or unbuildable dependency chain was: ['python3-paramiko', 'python3-pycrypto']
NOTE: Runtime target 'roslaunch' is unbuildable, removing...
Missing or unbuildable dependency chain was: ['roslaunch', 'python3-paramiko', 'python3-pycrypto']
ERROR: Required build target 'core-image-elphel393' has no buildable providers.
Missing or unbuildable dependency chain was: ['core-image-elphel393', 'roslaunch', 'python3-paramiko', 'python3-pycrypto']

• Error 2:
  • Seems like rostopic causes:

ERROR: python-imaging-1.1.7-r5 do_package_qa: QA Issue: python-imaging: The compile log indicates that host include and/or library paths were used.
         Please check the log '/home/oleg/GIT/elphel393_rocko_clean_install/poky/build/tmp/work/cortexa9-neon-poky-linux-gnueabi/python-imaging/1.1.7-r5/temp/log.do_compile' for more information. [compile- host-path]
ERROR: python-imaging-1.1.7-r5 do_package_qa: QA run found fatal errors. Please consider fixing them.
ERROR: python-imaging-1.1.7-r5 do_package_qa: Function failed: do_package_qa
ERROR: Logfile of failure stored in: /home/oleg/GIT/elphel393_rocko_clean_install/poky/build/tmp/work/cortexa9-neon-poky-linux-gnueabi/python-imaging/1.1.7-r5/temp/log.do_package_qa.19425
ERROR: Task (/home/oleg/GIT/elphel393_rocko_clean_install/meta/meta-openembedded/meta-python/recipes-devtools/python/python-imaging_1.1.7.bb:do_package_qa) failed with exit code '1'

potential links: 
 https://github.com/intel-aero/meta-intel-aero/issues/81
 https://github.com/bmwcarit/meta-ros/issues/395

removed python3-imaging from rosbag - everything builds but then not really working.

with ROS_USE_PYTHON3 = "yes" stopped at finding an appropriate python-pycrypto lib

Work

• Won't work

• • There's no rosrun (does not exist?)

• • SSH session 1:
    • Add to /etc/hosts:

127.0.0.1	elphel393.localdomain		elphel393

• • • Export vars:

export ROS_ROOT=/opt/ros
export ROS_DISTRO=indigo
export ROS_PACKAGE_PATH=/opt/ros/indigo/share
export PATH=$PATH:/opt/ros/indigo/bin
export LD_LIBRARY_PATH=/opt/ros/indigo/lib
export PYTHONPATH=/opt/ros/indigo/lib/python2.7/site-packages
export ROS_MASTER_URI=http://localhost:11311
export CMAKE_PREFIX_PATH=/opt/ros/indigo
touch /opt/ros/indigo/.catkin

• • • Roscore

roscore

• • SSH session 2:

root@elphel393:~# rosnode list
 /rosout
root@elphel393:~# rospack list
 cpp_common /opt/ros/indigo/share/cpp_common
 genmsg /opt/ros/indigo/share/genmsg
 genpy /opt/ros/indigo/share/genpy
 rosbag /opt/ros/indigo/share/rosbag
 rosbag_storage /opt/ros/indigo/share/rosbag_storage
 rosclean /opt/ros/indigo/share/rosclean
 rosconsole /opt/ros/indigo/share/rosconsole
 roscpp /opt/ros/indigo/share/roscpp
 roscpp_serialization /opt/ros/indigo/share/roscpp_serialization
 roscpp_tutorials /opt/ros/indigo/share/roscpp_tutorials
 rosgraph /opt/ros/indigo/share/rosgraph
 rosgraph_msgs /opt/ros/indigo/share/rosgraph_msgs
 roslaunch /opt/ros/indigo/share/roslaunch
 roslib /opt/ros/indigo/share/roslib
 roslz4 /opt/ros/indigo/share/roslz4
 rosmaster /opt/ros/indigo/share/rosmaster
 rosnode /opt/ros/indigo/share/rosnode
 rosout /opt/ros/indigo/share/rosout
 rospack /opt/ros/indigo/share/rospack
 rosparam /opt/ros/indigo/share/rosparam
 rospy /opt/ros/indigo/share/rospy
 rospy_tutorials /opt/ros/indigo/share/rospy_tutorials
 rostime /opt/ros/indigo/share/rostime
 rostopic /opt/ros/indigo/share/rostopic
 std_msgs /opt/ros/indigo/share/std_msgs 
 topic_tools /opt/ros/indigo/share/topic_tools
 xmlrpcpp /opt/ros/indigo/share/xmlrpcpp