imu plugin update rate problem

[Mondo92]

Hi everyone,

I'm trying to interface a quadrotor model in gazebo with the hector imu plugin with Matlab Simulink. The aim is to simulate the model dynamics entirely in Simulink and to only move it in Gazebo gazebo/set_model_state topic. Hence the physic is disabled.

I'm experiencing a problem with the Imu plugin measures. While keeping all drift and noise set to zero I get very different values by changing the update rate field that should be expressed in Hz.
With 200Hz (that should be the reference frequency for the imu I want to simulate) I get very low angular velocity values :

(y: ang vel [rad/s] x: time [s])
On the other hand, by setting up a update rate of 20Hz I get this very different but reasonable angular velocity values:

(y: ang vel [rad/s] x: time [s])
In both cases linear accelerations turned out to be correct.

I can't understand the nature of the problem so I would like to ask for help.
Regards.