ROS 2 Doctor
ROS2 Doctor is a diagnostic tool that succeeds ros wtf (where is the fault). It checks all aspects of ROS 2, including platform, version, network, environment, running systems. It’s part of the ros2cli package. So if ros2cli is installed, ROS2doctor is installed.
What Does ROS2 Doctor Check?
One can see ros2 doctor --report
- Package versioning, such as
tf2_bullet NETWORK CONFIGURATION, items like:inet : 192.168.1.65…
PLATFORM INFORMATION, items like:- like
platform info : Linux-6.9.3-76060903-generic-x86_64-with-glibc2.35
- like
QOS COMPATIBILITY LISTcompatibility status : No publisher/subscriber pairs found
ROS 2 INFORMATION:distribution name : humble
TOPIC LIST- Existence of “dangling” topics without subscribers.
One can check failed checks only (report fail): ros2 doctor -rf. Reference
What ros2 doctor Can’t Detect
- I had a mix of
ROS2 IronandROS2 Humble- ROS 2 Iron cannot directly listen to ROS 2 Humble messages due to ABI incompatibility and other changes between ROS 2 distributions. E.g.,
sensor_msgsthat has different symbols or behavior inIron
- ROS 2 Iron cannot directly listen to ROS 2 Humble messages due to ABI incompatibility and other changes between ROS 2 distributions. E.g.,
Ros2 Topic
In ROS 2 design, it’s generally good to keep in mind what QoS we might need for each topic
ros2 topic echo /your_topic --qos-reliability=best_effort- Messages might be dropped if the subscriber cannot keep up or if the network connection is unreliable.
- Can use
ros2 node info /wayfinder/head_stereo_camera/depth_left_camerato see which nodes are publishing / subscribing via this topic -
Checking pub-sub qos:
ros2 topic info TOPIC --verbose ros2 topic hzcurrentlty doesn’t have aqosoption-
Useful:
ros2 topic echo /diagnostics: monitors if there are dropped frames, overheating, etc. Any node can publish to/diagnostics. (Hardware drivers, software nodes, etc.) - QoS:
- In order to make the transition from ROS 1 to ROS 2 easier, exercising a similar network behavior is desirable. By default, publishers and subscriptions in ROS 2 have “keep last” for history with a queue size of 10, “reliable” for reliability, “volatile” for durability, and “system default” for liveliness. Deadline, lifespan, and lease durations are also all set to “default”.
best_effort= UDP,Reliable= TCP
Multicast
This command is a diagnostic tool that’s often used in ROS 2 for discovery and communication between nodes
ros2 multicast receive
ROS2 pkg
- Find the path to a package:
ros2 pkg prefix PKG
