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2020-08-24 02:22:01 -0500 asked a question Gazebo doesn't use GPU when run inside a container

Gazebo doesn't use GPU when run inside a container Hi Everyone, I have set up a singularity container (Ubuntu 16.04, Ro

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2016-03-01 05:42:14 -0500 commented question Odd robot/joint behaviour on high simulation speed

So do you mean I should add friction/damping to the Joint? Because at this moment, the default SDF for the Pioneer3DX does not have it. It only has mu,mu2,slip1,slip2 for the link of the wheels, and not the joint.

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2016-02-29 07:47:42 -0500 asked a question Odd robot/joint behaviour on high simulation speed

Dear All,

On an earlier question, Speeding Up Gazebo Physics Simulation, I found out how to increase the simulation speed significantly by using the latest gazebo and increasing max_step_size.

Now, I want to discuss an odd behavior which I observed on all the robot models in gazebo, including Pioneer 3DX, Pioneer AT, PR2, Youbot, and iRobot which is observable when the speed of the simulator is increased.

My observation:

  1. With the default max_step_size value(0.001), when the speed of the simulator is increased (by setting the real_time_update_rate to zero) all the above robots start moving around without any given value to the command velocity topic.
  2. If I increase the max_step_size to (0.05), these movements become very very big (10 meters radius), and some robots will just cease to work.
  • Notes: I have read similar other topics regarding this issue, but none of them were conclusive.

My questions are:

  1. Why this happens?
  2. Does this mean that my velocity commands will be affected by this problem?
  3. Is there a way for me to find out whether the question number two happens? It is quite impossible for me to see anything by eye when the simulator is running at 500x normal speed.
  4. Is it possible to fix this?

You can also see this behavior in the following YouTube video. Video Link

The PC used is an i7 with 8GB RAM and GTX980 Graphic Card.

2016-02-04 05:35:32 -0500 commented answer Speeding Up Gazebo Physics Simulation (Considering ROS Plugin usage)

I can confirm that with Gazebo 7.0 (compiled from source), I have no sensor assert problems, and I could speed up a very simple Pioneer 2 DX up to 430 times the real time speed with max_step_size of 0.05.

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2016-02-03 06:42:18 -0500 commented answer Speeding Up Gazebo Physics Simulation (Considering ROS Plugin usage)

Oh, great thanks. I guess then this is it. I got my answer. Thank you for you efforts.

2016-02-02 09:16:49 -0500 commented answer Speeding Up Gazebo Physics Simulation (Considering ROS Plugin usage)

I did increase the max_step_size to 0.01 (it means 100Hz update rate, right?), and I have the following problem: After some time, the gazebo SensorManager.cc gives an assertion failure. It says "Took over 1.0 seconds to update a sensor". I have to see whether this happens on gazebo7 as well or not.

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2016-02-02 02:22:13 -0500 commented answer Speeding Up Gazebo Physics Simulation (Considering ROS Plugin usage)

I see. Does gazebo use CPU to calculate the collision and dynamic engines or GPU? Because my GPU utilization is at 8%, while gazebo is using 4 of my 8 CPU cores (4 processes with usage 2.5+1.0+0.55+0.18 CPUs based on htop results). I will try installing the latest version. I am already using 10 machines to run separate simulations. Is it possible to run multiple gazebo's on the same machine?

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2016-02-01 11:07:01 -0500 asked a question Speeding Up Gazebo Physics Simulation (Considering ROS Plugin usage)

Dear All,

I was not sure whether to post this question here or on ROS answers page. But I think it is closer to gazebo than ROS.

My Objectives is to Speed up Physical simulation to the max speed (I use max_step_size=0.005 and real_time_update_rate=0.0). I have around 25xspeed up with a Pioneer 2 robot with a single camera, 4x bumper and an IMU sensor (NVIDIA Geforce GTX980 with i7-4790@3.60 GHz x8). I use Gazebo 2.2.3 which comes with ROS indigo.

I need MORE! The reason is that I do Reinforcement learning experiments with robots, and well, faster experiments mean easier life.

What I Need to have for My robot

  • Diff drive ( I use libgazebo_ros_diff_drive )
  • Camera ( liggazebo_ros_camera)
  • 4x Bumpers (I use 4 different link connected to chassis with libgazebo_ros_bumper)
  • IMU ( I use libgazebo_ros_imu or libhector_gazebo_ros_imu)

My Questions:

  • Why the speed of simulation drops so much when a robot is added? I have around 100x speed when an environment is loaded without a robot. Is this because of ROS plugins?
  • Does anyone know of any faster ROS plugins if they are the bottleneck?
  • Is there any other way for me to update the speed further without increasing more max_step_size?
  • Is there perhaps a faster physics engine that I can use? I tried bullet, but nothing really changed.

Notes

  • I already use very simple collision meshes both for my environment and my robot.
  • My environment texture does not use lighting reflection/effects.