I am using Isaac Sim to acquire IMU Sensor data at 120 Hz by changing the physics setting and physics scene settings to 120, allowing me to publish all sensor data at this rate.
However, in such cases, while the robot remains still without vibration, it starts oscillating as soon as it moves. (This does not happen if I don’t make these changes.) When I run SLAM with the data acquired this way, it doesn’t work due to IMU noise. Although I assumed zero IMU noise in the simulator, it seems that the robot’s oscillation is causing the IMU noise.
Is there a way to eliminate the vibration that occurs when the robot is in motion?
Or, is there a way to know the IMU Noise parameter in the Isaac Simulator?
@AlesBorovicka
I’m really sorry for tagging, But i couldn’t ask anymore because the below link is closed.
After solving the below issue, when i navigated the robot, the robots are vibrating when i handled the physics settings to 120. How can i solve?
Hi,
so this happens with the convex approximation right?
Please what IsaacSim version are you using? Can you please also try the CPU simulation? (In the Window->Simulation->Debug you can override the simulation between CPU/GPU or schema based).
I’m using the Isaac 2022.2.1 version now.
And then, When i change the “GPU/CPU Settings” from “shcema based”(default) to “Force CPU”, the robots are still vibrating when it driving.
But now i found something wrong.
In ROS Example (Hospital), I found that when the physics settings were set to default (30) and I followed the link and drove with only collision(Cyliners As Custom Geometry) turned off, it vibrated while driving. But when I turn this on, the robot doesn’t vibrate.
However, When I increase the physics setting to 120, if I do not turn off collision, large vibrations will occur when it is stationary, so I have no choice but to turn it off. However, if I turn this off, the robot will vibrate when driving.
Perhaps turning off collision is one of the reasons why vibration still occurs when driving even when I set the physics setting to 120.
I do not want unintentional vibrations to occur even when stationary or driving.
Is there any way to solve this?
Yeah absolutely, we need to figure out what is wrong. By any chance could you try this scene with the newer IsaacSim 2023? I tried this scene with 2023.1 last time and it looked good there, will try the 2022.2 version and move the robot around to see if I can repro your issues.
When I moved the hospital scene (2022.2.1) that I had modified myself and was using for research(paper work) to 2023.1 version, the scene was broken, so I am currently continuing to use 2022.2.1 to use our hospital scene.
Thank you so much for trying to reproduce and solve it.
I’ll be waiting for your answer.
Thank you
Hi @phr0201 - It would be great if you share what issues you observed when you updated to Isaac Sim 2023.1.1 version. It might be some settings or things that you might have to update, because many things have been updated since 2022.2.1 release.
I tried in Isaac Sim 2023.1.1 version. But it still vibrating when the robot drives if I turn off the Collisions (Cylinders As Custom Geometry).
And this is a separate question, but when I open the Tutorial hospital & office scene in version 2023.1.1, it renders a dark environment with no lights. What is the problem?
I was looking at the scene again and I might know what could be your issue.
So, when you say turn off collisions (Cylinder as Custom Geometry) its not really turning off the collisions, but it will simulate the cylinder with convex approximation, rather then through a custom geometry. (Cylinder is not supported natively inside PhysX SDK).
So when you have convex approximation its not perfectly round, hence you see the robot to bounce a bit, is that your vibration?
In order to mitigate this you have two options:
You replace the colliders with a sphere, this of course has the negative impact of having collisions that are around the wheels.
You can add complient contacts, you can do that by selecting the Wheelmaterial and there in the advanced settings you set the complient contact:
