Controller Manager doesn’t have any parameters related to the controllers , why so?

Question

Hi I created some controllers to control a mobile robot. When compile there is no error. Here is my controller launch file.

from launch import LaunchDescription
from launch_ros.actions import Node
from ament_index_python.packages import get_package_share_directory
from launch.substitutions import Command
import os

def generate_launch_description():
    # Path to URDF file
    urdf_file = os.path.join(get_package_share_directory('localisation_sim_task'), 'urdf', 'load_vehicle.urdf')

    # Path to the controllers configuration (params.yaml)
    params_file = os.path.join(get_package_share_directory('localisation_sim_task'), 'config', 'params.yaml')

    robot_description = Command(['xacro ', urdf_file])

    return LaunchDescription([
        # Robot state publisher to publish the URDF
        Node(
            package='robot_state_publisher',
            executable='robot_state_publisher',
            name='robot_state_publisher',
            output='screen',
            parameters=[{'robot_description': robot_description}],
        ),

        # Start ros2_control_node with the controllers from params.yaml
        Node(
            package='controller_manager',
            executable='ros2_control_node',
            parameters=[params_file],
            output='screen',
        ),

        # Load and start the arm position controller
        Node(
            package='controller_manager',
            executable='spawner',
            arguments=['arm_position_controller'],
            output='screen',
        ),

        # Load and start the shovel position controller
        Node(
            package='controller_manager',
            executable='spawner',
            arguments=['shovel_position_controller'],
            output='screen',
        ),

        # Start custom node for controlling the arm and shovel
        Node(
            package='localisation_sim_task',
            executable='arm_shovel_controller',
            name='arm_shovel_controller',
            output='screen',
        ),

        # Start steering velocity controller
        Node(
            package='localisation_sim_task',
            executable='steering_velocity_controller',
            name='steering_velocity_controller',
            output='screen',
        ),
    ])

And here is the cpp file

#include "rclcpp/rclcpp.hpp"
#include "std_msgs/msg/float64.hpp"

class ArmShovelController : public rclcpp::Node {
public:
    ArmShovelController() : Node("arm_shovel_controller") {
        arm_pub_ = this->create_publisher<std_msgs::msg::Float64>("/arm_position_controller/command", 10);
        shovel_pub_ = this->create_publisher<std_msgs::msg::Float64>("/shovel_position_controller/command", 10);

        // Publish commands to move the arm and shovel
        timer_ = this->create_wall_timer(
            std::chrono::milliseconds(100), std::bind(&ArmShovelController::publish_commands, this));
    }

private:
    void publish_commands() {
        auto arm_msg = std_msgs::msg::Float64();
        auto shovel_msg = std_msgs::msg::Float64();

        // Example positions
        arm_msg.data = 0.5;  // Example: move the arm to 0.5 radians
        shovel_msg.data = 0.2;  // Example: move the shovel to 0.2 radians

        arm_pub_->publish(arm_msg);
        shovel_pub_->publish(shovel_msg);
    }

    rclcpp::Publisher<std_msgs::msg::Float64>::SharedPtr arm_pub_;
    rclcpp::Publisher<std_msgs::msg::Float64>::SharedPtr shovel_pub_;
    rclcpp::TimerBase::SharedPtr timer_;
};

int main(int argc, char **argv) {
    rclcpp::init(argc, argv);
    rclcpp::spin(std::make_shared<ArmShovelController>());
    rclcpp::shutdown();
    return 0;
}

and the params.yaml file

arm_position_controller:
  ros__parameters:
    type: position_controllers/JointPositionController  # Define the type of the controller
    joint: arm_joint
    command_interfaces:
      - position
    state_interfaces:
      - position
      - velocity

shovel_position_controller:
  ros__parameters:
    type: position_controllers/JointPositionController  # Define the type of the controller
    joint: shovel_joint
    command_interfaces:
      - position
    state_interfaces:
      - position
      - velocity

steering_velocity_controller:
  ros__parameters:
    type: velocity_controllers/JointVelocityController  # Define the type of the controller
    joint: steering_joint
    command_interfaces:
      - velocity
    state_interfaces:
      - velocity

when run

ros2 param list /controller_manager

qos_overrides./parameter_events.publisher.depth
qos_overrides./parameter_events.publisher.durability
qos_overrides./parameter_events.publisher.history
qos_overrides./parameter_events.publisher.reliability use_sim_time

It seems that the

/controller_manager

node is running, but it doesn’t have any parameters related to the controllers themselves. Normally, you should see parameters like arm_position_controller, shovel_position_controller, etc., listed under /controller_manager

what can be the problem and how to fix it?