IMU added to the drone SDF file in Gazebo but data published via ROS is all zero

I modified the SDF file, adding the IMU sensor as this:

And then I try publishing the IMU data using PYTHON as this:

But when I use

rtopic echo /Imu_1

to show the data, they are all zero as this:

Really can’t solve, need help thanks!

Imitating the body IMU of the iris drone, I added the IMU plugin as shown, and subscribe to this topic, however, there is still no valid data but all zero. For the SDF file of PX4 in gazebo, is there any way to obtain the newly added IMU data? Do I have to use XACRO file? Anyone can help?

I am simulating a quadcopter-payload system, I need to use the data of the IMU on the payload to obtain sway angles. I am stuck here cause no data can be obtained…