From simulation to real robots

11.05.2013

From simulation to real robots

Dipl. Inform Michael Fritscher
Dipl. Inform Robin Heß1

Introduction
Simulation vs. real robot• Simulations allow– Easy and fast development– Save operation of untested algorithms– Repeatability• But suffer from– Simulation accuracy– Real world dynamics and timing– Often different interfaces compared to real robots• WHAT MUST WE DO TO BRING SIMULATION CLOSE TO REAL ROBOTS?

11.05.2013

From simulation to real robots

Dipl. Inform Michael Fritscher
Dipl. Inform Robin Heß2

Choosing Simulation environment• Player/Gazebo – free but lacks e.g. multi camera support• Webots – commercial, very expensive• Deltra3D – free but it seems to be fairly inactive• USARSim – free, used by e.g. the RoboCup=> USARSim chosen

11.05.2013

From simulation to real robots

Dipl. Inform Michael Fritscher
Dipl. Inform Robin Heß3

USARSimA high-fidelity simulator• Based on Unreal Tournament game engine• moderate hardware requirements, high speed physics engine and rendering
capabilities• Simulation of all important types of robots with adjustable parameters:– Wheeled robots - Car-like (2WD and 4 WD), Differential drive, …
– Arial robots – Quadrocopter, …

• Simulation of most important sensors:– Range (LODAR, sonar, IR)– Position (INS, GPS, Wheel sensors)– Camera (Multi camera views)

11.05.2013

From simulation to real robots

Dipl. Inform Michael Fritscher
Dipl. Inform Robin Heß4

How to integrate a real robot in USARSim?
USARSim setup• Setting up robot using existing USARSim models and sensors• Adjusting parameters to fit the real robot• Develop maps according to real facilities

11.05.2013

From simulation to real robots

Dipl. Inform Michael Fritscher
Dipl. Inform Robin Heß5

How to integrate a real robot in USARSim?
Problem: Different interfaces of simulation and robot systems (single connection vs.
multi connection)
USARSim

Base unit

Main unit

RS232

INS

Core Node

Simcore Node

INS Node

Camera Node

LIDAR Node

RS232

GPS NodeGPS

Ethernet

AltURI

Camera Node

USB
LIDAR

Ethernet

CameraEthernet

11.05.2013

From simulation to real robots

Dipl. Inform Michael Fritscher
Dipl. Inform Robin Heß6

How to break the single simulation connection?
Overview

DriverID
Publisher
Callback

DriverSelector
USAR packet

DriverList
newSimulationPacket
addDriverremoveDriver
selectDriver

Select Driver

SimulationCore

ROS topic

LaserDriver
INSDriver

ROS…

USAR
sim
11.05.2013

From simulation to real robots

Dipl. Inform Michael Fritscher
Dipl. Inform Robin Heß7

How to enable multi-node architecture?
• SimulationCore extended by service registerExternalDriver– Special extDriver added to DriverSelector once services is called– No processing of data and publishing as normal ROS data types by extDriver– Data serialized and published over special extDriverPublisher• ExternalDriverNode– Calls registerExternalDriver service (sets extDriverPublisher topic)– Subscribe to extDriverPublisher topic– Deserialize data, and do all processing (existing drivers may be foundation)

11.05.2013

From simulation to real robots

Dipl. Inform Michael Fritscher
Dipl. Inform Robin Heß8

Use-Case: SiNafaR overview
The rough…

11.05.2013

From simulation to real robots

Dipl. Inform Michael Fritscher
Dipl. Inform Robin Heß9

Use-Case: SiNafaR overview.. And the fine view

11.05.2013

From simulation to real robots

Dipl. Inform Michael Fritscher
Dipl. Inform Robin Heß10

… and a screenshot of the GUI

11.05.2013

From simulation to real robots

Dipl. Inform Michael Fritscher
Dipl. Inform Robin Heß11

Conclusion• Benefits of using simulation in aspects of cost, efficiency, …

• Complete and dynamic integration of USARSim simulation environment into ROS andROSenabled robots• Easy change between simulation and real robots (matter of exchanging one module)• Multi node architecture in simulation and reality• Reuse of existing driver code in simulations• Use of the stockpile of ROSs modules possible

11.05.2013

From simulation to real robots

Dipl. Inform Michael Fritscher
Dipl. Inform Robin Heß

12

Future Work

• Bidirectional communication between externalDriverNodes and Simulation• Configuration of robot sensor systems using launchfiles• Analysis of overhead of the presented system• Calibration of simulated cameras

11.05.2013

From simulation to real robots

Dipl. Inform Michael Fritscher
Dipl. Inform Robin Heß13

Thank you!

Questions?

11.05.2013

From simulation to real robots

Dipl. Inform Michael FritscherDipl. Inform Robin Heß14