CLOiSim : Multi-Robot Simulator

Happy to announce CLOiSim. It is a new multi-robot simulator that uses an SDF file containing 3d world environemnts and robot descriptions.

The simulator is based on Unity 3D. It may look similar to Gazebo, where, unfortunately, we encountered performance problems while loading multiple robots equipped with multiple sensors. Hence, CLOiSim.

This project consists of

• SDF Parser for C#
• SDF Robot Implementation for Unity -> Visual / Collision / Sensor / Physics for joints
• SDF Plugins for Unity3D
• UI modules -> Module for on-screen information
• Network modules -> Module for transporting sensor data or control signal
• Web service -> Module for controling simulation through a web interface

video link

Notices

Working branch policy has been updated. Previous latest main branch which is corresponding to release-3.2.0 branch is no longer available. So please check release-3.2.0 branch if you want to follow the history of CLOiSim-3.x.x. develop branch shall be merged into main branch every released.

Features

Sensors

The current release includes the features only for marked items in the list below. Other sensor models are work in progress. Here are the list of items that is implemented(marked) or planned to be implemented.

• Joint models
  • Joint control
  • Joint Pose
• Sensor models
  • LiDAR Sensor
    • 2D: Due to performance issue, < 40hz is recommended
    • 3D
  • Sonar sensor
  • IMU
  • Contact
  • Camera: Due to performance issue, < 40hz is recommended
    • Camera intrinsic parameter
    • Depth Camera
    • Multi-camera
    • RealSense (RGB + IR1 + IR2 + Depth)
    • Semantic Segmentation Camera
  • GPS sensor
  • Sensor noise models
    • Gaussian
      • GPS, IMU
      • Lidar
      • Camera
    • Custom
• Physics
  • Support all physics parameters in SDF specification
  • Support <Joint type="revolute2">
• Worlds
  • Actors
    • interpolate_x in <animation>
  • Lights
    • supporting <specular>, <attenuation/linear>, <attenuation/contant>, <attenuation/quadratic>, <spot/falloff>
  • Spherical Coordinates
  • Heightmap (DEM)
    • Support GeoTIFF
    • Texture Blend
  • Road

Plus, SDF file basically targeting and supporting version 1.6 and works on the essential elements such as <model>, <link>, <visual>, <collision>, <joint>, etc.

It does not support optional elmenets like <wind>, <audio>, <state>, <atmosphere>, <magnetic_field>, <scene>, <population>.

There is problem with <pose> in <joint> since introduction of articulation body model. Therefore, plaese

Currently, geometry mesh type is supporting only 'Wavefront(.obj) with material', 'Collada(.dae) including animation' and 'STL(.stl)'. <ambient> elements in <materal> and ambient properies in mesh files are not support in CLOiSim.

If you're trying to connect <link> of <model>, it needs to specify unique name in link name in joint/parent or joint/child within same root model.

video link

Sensor Plugins

It called 'CLOiSimPlugin'. And below plugins could be utilized through write an element on SDF.

Plugin name should be written in filename attribute and it's case sensitive.

For example,

<plugin name="actor_plugin" filename="libActorPlugin.so" />

More details and usages for configuration/parameters in here.

Model Specific

• LaserPlugin: help to publish 2D or 3D lidar data
• CameraPlugin: help to publish 2D color image data or depth image data
• SegmentationCameraPlugin: help to publish semantic segmentation image data and label info
• MultiCameraPlugin: help to publish multiple color image data
• RealSensePlugin: can handle ir1(left), ir2(right), depth, color
• MicomPlugin: control micom(differential drive) input/output(sensor)
  • 2/4-Wheeled Motor differntial drive
  • 2-Wheel Self-balancing drive
• GpsPlugin: gps position in world
• JointControlPlugin: can control joints and help to publish joints status.
• ActorPlugin: add actor control functionality using AI(Unity) components
• ImuPlugin: help to publish IMU sensor data
• SonarPlugin: help to publish Sonar range data
• ParticleSystemPlugin: Enable particla system of Unity

World Specific

• ElevatorSystemPlugin: control(lifting, cal) elevators
• GroundTruthPlugin: retrieve all information(position, size, velocity) for objects
• ActorControlPlugin: controls actor using AI(Unity) components(actor which loaded ActorPlugin)
• MowingPlugin: plant grass and enable to mow

How it works

Refer to core codes in 'Assets/Scripts'.

• Load SDF file -> Parse SDF(simulation description) -> Implement and realize description

Shaders are also used to get depth buffer information in a few sensor model.

Default physics engine 'Nvidia PhysX' is used for physics. And it retrieves some of physics parameters from <ode> in sdf. 'SDFPlugins' help physics tricky handling for jointing <link> ojbects by <joint> element.

We've deceided to change a solver type of physics engine since new solver "TGS(Temporal Gauss Seidel)" is intorduced recently(PhysX 4.1).

So there is NO more constaints for rigidbodies by PGS(Projected Gauss Seidel) solver type since latest version(CLOiSim-1.11.0).

For the performance in terms of collision handling, designing collision geometry properly may important.

an aspect of rendering

if <name> element of <script> element in <material> element contains "tree" words, CLOiSim applies "URP/Nature/SpeedTree" Shader as a rendering material.

Getting Started

Minimum requirement

• Processor: testing and looking for the minimum
• Memory: testing and looking for the minimum
• Graphics: testing and looking for the minimum

Tested environement (latest)

• Unity Editor Version: '2022.3.54f1 (LTS)'.

• Linux Machine

  • OS: Ubuntu 22.04.5 LTS
  • Processor: AMD® Ryzen 9 5950x 16-core processor × 32
  • Memory: 128.0 GiB
  • Graphics: NVIDIA Corporation [GeForce RTX 3090]

• Windows Machine

  • OS: Windows 10 20H2
  • Processor: AMD® Ryzen 9 5900HS 8-core processor x 16
  • Memory: 32GB
  • Graphics: NVIDIA GeForce RTX3060 Laptop GPU

Release version

If you don't want to build a project, just USE a release binary(Download linux version). And just refer to 'Usage' section.

In terms of branch, 'main' is release(stable) version, and 'develop' is used for development(on-going).

If you want to build a project

Please visit here build guide in Wiki pages.

Usage

Any problem during launching the simultion, please refer to Wiki Page/Usage' section.

Run 'CLOiSim'

Set environment path like below. You can find the sample resources here

Multiple path can be set by :(colon).

export CLOISIM_FILES_PATH="/home/Unity/cloisim/sample_resources/media"
export CLOISIM_MODEL_PATH="/home/Unity/cloisim/sample_resources/models:/home/Unity/cloisim/another_resources/models"
export CLOISIM_WORLD_PATH="/home/Unity/cloisim/sample_resources/worlds"

Run CLOiSim

 ./run.sh cloisim.world

or you can execute binary file directly.

./CLOiSim.x86_64 -world lg_seocho.world

Run 'cloisim_ros' after running CLOiSim

• You need to run this package in order to publish sensor data in ROS2.

• Run bringup node in 'cloisim_ros' ros2 packages

• Latest version of CLOiSim will support only humble version of ROS2

• That's it. Have fun!!!

Debugging log

tail -f ~/.config/unity3d/LGE.CTO.AdvancedRoboticsLab/CLOiSim/Player.log

Control and external UI service

CLOiSim supports web-based control service through websocket as an external interface.

websocket service path: ws://127.0.0.1:8080/{service-name}

You can add markers like line, text, box, or sphere point and reset simulation by just sending a request data as a JSON format.

Read detail guide in Wiki pages.

CLOiSim + nav2

video link

Future Plan

New features or functions shall be developed on demand.

• Fully support to keep up with the latest version of 'SDF specifiaction'

  • Considering wrapper class for SDF c++ library.

• Add new sensor models and enhance sensor performance

• introduce programmable c++ plugin

• Performance optimization for sensors (Use DOT by unity?)

• Upgrade quality of graphical elements

• If you have any troubles or issues, please don't hesitate to create a new issue on 'Issues'. https://github.com/lge-ros2/cloisim/issues

감사합니다. Thank you