Revision history [back]

The publishers for sensor_mshs, such as IMU, are created with reliability=best-effort and durability=volative and are incompatible with the default QoS profile. You can inspect the QoS policy for the imu topic using:

ros2 topic info -v /imu

Node name: my_imu_plugin
Node namespace: /imu
Topic type: sensor_msgs/msg/Imu
Endpoint type: PUBLISHER
GID: 01.0f.7a.c1.3b.98.3e.00.01.00.00.00.00.00.39.03.00.00.00.00.00.00.00.00
QoS profile:
  Reliability: RMW_QOS_POLICY_RELIABILITY_BEST_EFFORT
  Durability: RMW_QOS_POLICY_DURABILITY_VOLATILE
  Lifespan: 2147483651294967295 nanoseconds
  Deadline: 2147483651294967295 nanoseconds
  Liveliness: RMW_QOS_POLICY_LIVELINESS_AUTOMATIC
  Liveliness lease duration: 2147483651294967295 nanoseconds

Read about QoS compatibilities to see a table of what subscriber QoS settings are compatible with publishing QoS. Create your subscriber with the following QoS profile:

   imu_qos = QoSProfile(
        depth=1,
        reliability=QoSReliabilityPolicy.BEST_EFFORT,
        durability=QoSDurabilityPolicy.VOLATILE)

  self.imu_data = self.create_subscription(
        Imu,
        'imu',
        self.imu_callback,
        imu_qos)

import these types:

from rclpy.qos import QoSDurabilityPolicy
from rclpy.qos import QoSReliabilityPolicy
from rclpy.qos import QoSProfile

The publishers for sensor_mshs, sensor_msgs, such as IMU, are created with reliability=best-effort reliability=BEST_EFFORT and durability=volative durability=VOLATILE and are incompatible with the default QoS profile. You can inspect the QoS policy for the imu topic using:

ros2 topic info -v /imu

Node name: my_imu_plugin
Node namespace: /imu
Topic type: sensor_msgs/msg/Imu
Endpoint type: PUBLISHER
GID: 01.0f.7a.c1.3b.98.3e.00.01.00.00.00.00.00.39.03.00.00.00.00.00.00.00.00
QoS profile:
  Reliability: RMW_QOS_POLICY_RELIABILITY_BEST_EFFORT
  Durability: RMW_QOS_POLICY_DURABILITY_VOLATILE
  Lifespan: 2147483651294967295 nanoseconds
  Deadline: 2147483651294967295 nanoseconds
  Liveliness: RMW_QOS_POLICY_LIVELINESS_AUTOMATIC
  Liveliness lease duration: 2147483651294967295 nanoseconds

Read about QoS compatibilities to see a table of what subscriber QoS settings are compatible with publishing QoS. Create your subscriber with the following QoS profile:

   imu_qos = QoSProfile(
        depth=1,
        reliability=QoSReliabilityPolicy.BEST_EFFORT,
        durability=QoSDurabilityPolicy.VOLATILE)

  self.imu_data = self.create_subscription(
        Imu,
        'imu',
        self.imu_callback,
        imu_qos)

import these types:

from rclpy.qos import QoSDurabilityPolicy
from rclpy.qos import QoSReliabilityPolicy
from rclpy.qos import QoSProfile

The publishers for sensor_msgs, such as IMU, are created with reliability=BEST_EFFORT and durability=VOLATILE and are incompatible with the default QoS profile. You can inspect the QoS policy for the imu topic using:

ros2 topic info -v /imu

Node name: my_imu_plugin
Node namespace: /imu
Topic type: sensor_msgs/msg/Imu
Endpoint type: PUBLISHER
GID: 01.0f.7a.c1.3b.98.3e.00.01.00.00.00.00.00.39.03.00.00.00.00.00.00.00.00
QoS profile:
  Reliability: RMW_QOS_POLICY_RELIABILITY_BEST_EFFORT
  Durability: RMW_QOS_POLICY_DURABILITY_VOLATILE
  Lifespan: 2147483651294967295 nanoseconds
  Deadline: 2147483651294967295 nanoseconds
  Liveliness: RMW_QOS_POLICY_LIVELINESS_AUTOMATIC
  Liveliness lease duration: 2147483651294967295 nanoseconds

Read about QoS compatibilities to see a table of what subscriber QoS settings are compatible with publishing QoS. Create your subscriber with the following QoS profile:

   imu_qos = QoSProfile(
        depth=1,
        reliability=QoSReliabilityPolicy.BEST_EFFORT,
        durability=QoSDurabilityPolicy.VOLATILE)

  self.imu_data = self.create_subscription(
        Imu,
        'imu',
        self.imu_callback,
        imu_qos)

or you can use the sensor-data preset profile instead:

imu_qos = rclpy.qos.QoSPresetProfiles.get_from_short_key('sensor_data')

import these types:

from rclpy.qos import QoSDurabilityPolicy
from rclpy.qos import QoSReliabilityPolicy
from rclpy.qos import QoSProfile