Noisy IMU sensor on Carter V1

[nilesh3]

Hello all,
I am new to Isaac sim and was playing around with Carter V1. I have created an IMU Sensor on the Carter V1 platform. The IMU sensor is child of IMU cube object.

I am accessing the imu readings via python interface. The rendering is running @ 50 Hz while Physics is running at 400 Hz.

On each physics update I am reading the latest IMU reading and publishing to a ROS topic.

I am running the simulation with differential controller set to both zero angular velocity and zero linear velocity. I have plotted the graph of IMU reading attached below -

I believed that for a stationary robot the X and Y axis accelerations would be zero, but they aren’t, especially the Y-acceleration is bit too noisy. How can I reduce this noise?

Thanks,
Nilesh

[Hammad_M]

Thanks for reporting this @nilesh3
The current IMU sensor is unfiltered, so you see the raw values from PhysX basically, resulting in numerical noise coming through. We will add a parameter to control the number of frames the data is averaged over to make this more useful.

[phr0201]

@nilesh3 Hello,

I want to also get the imu data topic in Isaac Sim (2022.1.1) based on ros2.
But i suffered the problem that the imu hz is too low ( that imu hz is same with the camera topic fps [ = viewport fps] ).
I published the imu topic using Omnigraph.

How can you get the imu topic to 400 hz?

[nilesh3]

Hi @phr0201 , you won’t be able to get the imu at 400 Hz using the Action Graph method. You have to follow either the extension workflow or standalone workflow .Read the imu data using python and then publish it. There is one example on IMU - IMU Sensor — Omniverse Robotics documentation

You have to set the physics simulation frequency to 400 Hz.

[phr0201]

Thank you for reply me!

Is physics Simulation frequency means "sensor_period" in property tab of imu_sensor ??