Isaac IMU Sensor data problem (physics_scene time steps per second Fix )

I’m trying to get the imu and rgb data from isaac simulator and run the SLAM algorithms.

But I have some problems to get the imu data from isaac sim. I tried many things for getting the imu sensor data. But I failed to run the SLAM algorithms using my own imu data from isaac simulator.

Below is the methods that i tried so far.

  1. Using Actiongraph
    Set the 200 in the physics scenes and Min Simulation Frame Rate for getting the imu sensor data 200 hz. And Using Action graph, I published the imu and rgb data. I can get the sensor topics to 200 hz. ( Like below figure )

    But I felt that this method is something wrong.
    If the real data acquisition time(Not sim, real-world) actually took 60 seconds(1minute), the recorded rosbag data was recorded for about 15 seconds, almost 1/4 times shorter. And when checking the rgb data, it seemed to be fast-forwarded.
    For various reasons, this method is actually acquired at 60(default time steps per second), but it looks like data that only sets the timestamp of each topic message to 200 hz. Since this is really fast-forwarding the data, I wondered if the imu data, which takes time in units, is wrong.
    Is it true? If it is true, i felt that the imu sensor data acquired from this method is wrong data because the imu data is related to time (unit m/s2).
    Also, I couldn’t know the noise parameters of imu sensor in isaac sim and the other forum issue said that the imu noise is all 0.000. So I set the noise parameter all 0.000, and when i run the ORB-SLAM3, i failed to run.
    => But in tutorial for running the Vins-fusion using isaac sim, I checked that tutorial also publish like this method(setting phyiscs scene hz) using python script… I’m really confused what is the correct answer…

  2. Write the publish code manually & Extract the raw imu data to csv file
    This method acquire the data irregular. Time interval is not regular. Below is the code that i acquire the imu raw data in csv file. (5.3 KB)

To sum up :

  • The first method(using actiongraph) is correct process to get the imu sensor data (200hz)? I felt that imu data is wrong data.
  • Is there any methods that acquire the correct imu data to over 200 hz ?

If anyone know this problem, please help me… I have suffered this problem for long time. I really hope to solve this problem…