RoboCup Rescue Simulation

1. RoboCup Rescue Simulation Barış Eker April 2005

2. CONTENT • Robocup Rescue • RoboAKUT 2005 • Discussion

3. RoboCup Rescue • Rescue League • Disaster environment is simulated in real world • Real robots are used • Final aim is to search&rescue • First step is searching and finding important points in disaster environment, civilians, fires, etc.

4. What is RoboCup Rescue? • Rescue Simulation League • Disaster environment is simulated in computer • Aims to simulate large urban areas • 2D simulation (Although simulation is in 2D, 3D viewer is now available) • Agent programs are written to run on this environment • Aim is to both search&rescue

5. Rescue Simulation League • Multi-agent approach, heterogeneous agents, rescue strategies are tested • Seven different types of agent • Ambulance, fire fighter, police agents and control center agents for each of them, and civilians • Cooperation is needed among agents • Most cases, individual agents are insufficient to deal with problems • Communication is limited

6. Structure of the Simulation Environment • Real-time distributed simulation system • Several modules that connect to a network • Each module can run on a different computer to reduce the computational load • Each phenomenon is simulated by different simulators • E.g. collapse of buildings, fire, etc. • GIS provides initial condition of disaster space • Viewer makes the visualization

7. Progress of RCRSS • The kernel sends individual vision info to each RCR agent • Each agent submits an action to kernel • The kernel sends these commands to sub-simulators • Sub-simulators submit the updated states to kernel • Kernel integrates the received states and send it to viewer • The kernel advances simulator clock

8. Progress of RCRSS • One cycle in simulation corresponds to one minute in disaster space • The kernel waits half a second for command/state submissions at steps 2 and 4, so a cycle takes a second • It occasionally takes a few seconds according to scale of the simulation and machine specs • All RCR agents must decide in half a second

9. RoboCupRescue Agents • An RCR agent controls act of an object in the disaster space • Seven classes • Civilian, AmbulanceTeam, FireBrigade, PoliceForce, AmbulanceCenter, FireStation and PoliceOffice • Platoon agents: Ambulance Team, Fire Brigade and Police Forces • Center agents: Ambulance center, Fire Station and Police Office • Rescue agents: Platoon agents + Center agents OR All agents – Civilian agents

10. RoboAkut • Reinforcement learning used in previous years • This year, all team is written from scratch • Task-based multiagent approach • Tasks are assigned from centers, however the agents can also act autonomously • Platoon agents collect the sensory information and send necessary ones to their centers

11. Ambulance Team • Start with exploring buildings assigned by center • If any civilian found, they are reported to center and the one that has the highest priority is started to be saved • Rescue agents has highest priority • Among civilians, having less estimated life(hp/damage) has more priority

12. Ambulance Team • Center opens auction for reported buried civilians and platoon agents respond by bidding • The bid values are determined by the distance from target, however this may be improved • Agents are assigned roles • Owner role : deals with job until it finished (with success or failure) • Helper role : deals with job until job finishes or owner role for another job is assigned • By that way, more than one agent is assigned to job when available, this increases efficiency

13. Ambulance Center • At the beginning, divides the disaster space into regions and assigns to platoons • Holds list of reported civilians and open auctions for them • Waits for two clock tick • Concludes the auction and inform the winners (owner and helper) • If owner does not send confirmation message, auction is re-opened for the civilian

14. Ambulance Center • Civilians are hold in a priority list • Reported by ambulance teams and from other centers • Priority is determined by • Estimated remaining life • Having less life, has more priority • Estimated rescue time • Having less rescue time, has more priority • At first, we want to save the ones that has minimum life and easiest to save • What can be done ? • Better remaining life estimation can be done via learning • Better metrics can be proposed • By that way, we may increase the overall efficiency of the team

15. Fire Brigades • Fire brigades also works with auction mechanism, but auction is not opened for each building • Fires should be extinguished in early stages, otherwise it becomes much harder • Therefore, quicker response required • Auction is opened for representative building for a region

16. Fire Brigades • All firebrigades assigned to a region deals with representative building at first • When fieryness property becomes 2, fires start spreading • In that case, helper firebrigades start extinguishing neighbour fires, because they can be extinguished more easily and by that way spreading can be prevented • Owner deals with representative building until it is extinguished or completely burned • Helpers are assigned index from center • The agent having index 1, deals with most recent fire, the agent having index 2, deals with next most recent

17. Fire Center • Holds the list of known fires • Fires represent regions • If a new fire is reported, it is checked whether it is in one of the known regions • After center assign a region to firebrigades, it sends clear region command to police center

18. Police Agents • Deals with the job assigned by their center • Clear region : If a region is assigned, all roads in this region are cleared • Clear road : If a road is assigned, it is reached and cleared • Report their position in each clock tick • Sends confirmation message when “clear region” message is taken • Informs center, when “clear region” job is finished • While path planning, other agents do not use blocked roads, but police agents use them and clear while passing

19. Police Center • Collect “clear road” and “clear region” messages from other centers • Assigns jobs to nearest polices • For “clear region” waits for confirmation message, if not taken, re-assignes the region

20. Communication • We used a common mechanism for message sending • Each agent has a “Message Sender” • “Message Sender” collects the messages in different queues according to their priority • “Message Sender” controls the maximum number of sendable messages in each clock tick • Unsent messages remain to be sent in next clock tick, by that way no message remains unsent • Each agent gives the message type while sending, “Message Sender” knows the priority of messages and puts them into related list

21. Problems • Need a better life estimator for ambulances • Need a better priority metrics for ambulance center, the rescue order of civilians is very important • Can auction or cost mechanism be improved? • Need a better way to extinguish boundary fires • Traffic jam • What if centers fail? • Communication between heterogeneous agents fail • Are platoon agents autonomous enough?