[ROS2][rclpy] Load parameters from file does not work when using namespaces
As the title says, I'm currently trying to load some parameters from a parameters.yaml file which is formatted as shown below:
nodename:
ros__parameters:
val1: 1
val2: 2
This parameter file is loaded to the node using a nodename.launch.py file as shown below:
return LaunchDescription([
Node(
package='nodename',
node_namespace='/',
node_executable='nodename',
node_name='nodename',
output='screen',
emulate_tty=True,
parameters=[
path_to_parameters,
],
)
])
The node itself is started by setting allow_undeclared_parameters=true and automatically_declare_parameters_from_overrides=true while my code inside of the constructor of the Node loads the parameters as displayed here:
# load parameters
val1_default = rclpy.parameter.Parameter(
"default_behavior",
type_=rclpy.parameter.Parameter.Type.INTEGER,
value=1
)
val1 = self.get_parameter_or("val1", val1_default).value
All this works fine as long as I don't change the nodes namespace in the launch file by e.g. setting node_namespace='robot1'. I have already played around with the name of my parameter where it is loaded in the code by e.g. applying the namespace name as a prefix. I also tried to changed the .yaml file according to the parameter file description documentation by e.g. including the namespaces name in the parameter file as described here. Unfortunately nothing of this works for me so I would be very thankful if someone could give me some advice.
Edit: I forgot to mention that I'm using ROS2 Eloquent Elusor on Mint/Ubuntu
Hey, did you solve it? I am having the same problem, just with c++.
Unfortunately not, instead I kept using the "workaround" to simply define the default parameter inside the code as shown here:
# load parameters val1_default = rclpy.parameter.Parameter( "default_behavior", type_=rclpy.parameter.Parameter.Type.INTEGER, value=1 ) val1 = self.get_parameter_or("val1", val1_default).valueI'm very unhappy with this solution. If you find a better one that does not include to write an own parameterloader I would be very happy if you could share it.
Hey, so I was able to replicate the "normal" ROS1 behavior, meaning, parameters work for me even when the node is namespaced and when the node name changes (I hope I understood your question well and this is what you asked about). Strangely, to achieve this I do exactly the opposite of what the tutorials say --- I do not put the
node_nameandros__parametersinto the yaml file. Here is my "hello world": https://github.com/ctu-mrs/ros2_uav_example.Hey, I tried your purposed solution. In python (still eloquent) it results in an instant
process has died [pid 14645, exit code -6error. But I haven't tried an other parameter loading method (e.g. using declare_parameter) than showed in my question above like you used. Nonetheless, it seems to be a problem of the reading of the YAML file since the node crashes before it is actually started (or at least before parameters are loaded).I am also trying to find a way to load parameters from a
.yamlfile in a way that is namespace-agnostic, but not node name-agnostic. It's unfortunate this doesn't seem to be possible. The/**:wildcard mentioned in other answers like here only works if there aren't parameters for different nodes in the same.yamlfile.