TRAIL/TNO Project 16
Fault detection and recovery in multi-modal
transportation networks with autonomous mobile actors
Jonne Zutt
Delft University of Technology
Supervisors
Dr. C. Witteveen
Information Technology and Systems
Collective Agent Based Systems Group
Dr. ir. Z. Papp
Dr. ir. A.J.C. van Gemund
www.rsTRAIL.nl
Content
1. Outline of the project
2. Problem setting:
Transport Planning Problem
3. Set-up of experiments
4. Preliminary results of experiments
5. Achievements / Future plans
www.rsTRAIL.nl
Project Characteristics
“Fault detection and recovery in multimodal transportation networks with
autonomous mobile actors”
•
•
•
•
Planning, fault detection and recovery
Multi-agent approach
Multi-layered approach for distributed planning
Operational aspect of multi-modal transportation
www.rsTRAIL.nl
Applications
• Autonomous Guided Vehicle (AGV) terminal,
– FTAM-5/6 (Davinci)
– Simple infrastructures with capacity restrictions and many
conflicts
• Taxi-cab companies,
– SMM-6 (M.M. de Weerdt)
– Medium infrastructure sizes, few capacity restrictions
• Freight transportation, distribution centers
– FTAM-1 (L.D. Aronson)
– Large infrastructures without capacity restrictions
• Multi-Agent diagnosis
– STW: Distributed Model-Based Diagnosis and Repair
– Fault detection and recovery
www.rsTRAIL.nl
Transport Planning Problem
•
•
•
•
Transportation orders
Infrastructure resources
Transport resources
Agents
www.rsTRAIL.nl
TPP – Orders
Transport Planning Problem:
•
•
•
•
Transportation orders
Infrastructure resources
Transport resources
Agents
O = (f, v, s, Ts, d, Td, l, u, p)
f, v
s, d
Ts, Td
l, u
p
freight identifier / volume,
source / destination location,
source / delivery time-window,
loading / unloading costs,
penalty.
www.rsTRAIL.nl
TPP – Infrastructure
•
•
•
•
Transportation orders
Infrastructure resources
Transport resources
Agents
www.rsTRAIL.nl
TPP – Infrastructure model
•
•
•
•
Transportation orders
Infrastructure resources
Transport resources
Agents
www.rsTRAIL.nl
TPP – Transport resources
•
•
•
•
Transportation orders
Infrastructure resources
Transport resources
Agents
www.rsTRAIL.nl
TPP – Agent architecture
TAC
CUS
Transportation
orders
OPR
CRA
Transport
resources
Infrastructure
resources
www.rsTRAIL.nl
Incident Management
What are incidents?
 Any event from outside the planning system that
cannot be anticipated with certainty.
•
•
•
new orders, changes in orders
road blocks, traffic jams
malfunctional vehicles
What is incident management?
• Ensuring the correct operation of a system under
the events of incidents
•
Detection, repair and notification of problems
www.rsTRAIL.nl
Contents
1. Outline of the project
2. Problem setting:
Transport Planning Problem
3. Set-up of experiments
4. Preliminary results of experiments
5. Achievements / Future plans
www.rsTRAIL.nl
Generating infrastructures
• Locations:
Retrieve a list of related postal codes, convert
to latitude / longitude,
then to (x, y) coordinates,
• Arcs:
Paul Bourke’s efficient triangulation algorithm
(for terrain modeling)
– As equilateral as possible (avoiding wedge shaped
triangles),
– Fast  O(n·log(n)).
www.rsTRAIL.nl
Generating transportation orders
1. Generate a (possibly infeasible) set of
transportation orders using several statistical
functions,
2. Generate a feasible set
•
•
Create random plans for the transport agents by
just letting them drive around,
Extract a set of orders they could have been
executing (using a density parameter),
www.rsTRAIL.nl
Contents
1. Outline of the project
2. Problem setting:
Transport Planning Problem
3. Set-up of experiments
4. Preliminary results of experiments
5. Achievements / Future plans
www.rsTRAIL.nl
Distributed operational planning
• Job-shop Scheduling with Blocking
Hatzack & Nebel (ECP 2001)
• JS scheduling: find an optimal allocation of a set R of
scarce resources to a set of activities (jobs) J over
time
• Blocking means that a resource is claimed by a job
until it claims the next resource
• Agent plan: ((IR1, 0-2), (IR2, 5-7), (IR3, 8-9) …)
www.rsTRAIL.nl
Experiments
• Used 3 different
infrastructures,
• 20 transport agents each
execute one order,
• Randomly chosen
source-, destination
location and fixed timewindow,
• H&N algorithm with
rerouting.
www.rsTRAIL.nl
Results (averaged over 100 problem instances)
Tardiness  aA Ca - a if Ca< a
Tardiness
Average % of delay
Delay  { aA (Ca – Ma) / Ca } / |A|
Number of alternatives
Number of alternatives
www.rsTRAIL.nl
Achievements
• AGV Terminal Demonstrator (delayed,
Mar’03)
• D**: dynamic (re)routing algorithm for AGVs
in a terminal [FTAM02 / TRAIL02]
• Distributed operational planning using Hatzack
& Nebel’s approach [BNAIC02]
• Development Uptime tool for multi-agent
based diagnosis [SPIE02]
www.rsTRAIL.nl
Future Plans
• Complete problem instances for the
experiments,
• Survey on routing and conflict resolution
algorithms,
• Build Incident Generator,
• Redo experiment, this time influenced by
incidents,
• Delivering an efficient and robust
demonstrator.
www.rsTRAIL.nl
The End
www.rsTRAIL.nl
Example infrastructure (1)
www.rsTRAIL.nl
Example infrastructure (2)
www.rsTRAIL.nl
Need for complex experiments
• AGV terminals usually have very simple
infrastructures.
– This is to keep things easy, not efficient,
– As terminals become larger, the problem will return.
www.rsTRAIL.nl
Properties of these infrastructures
• Many routes from a source location to a
destination location,
• The arcs (and their cost values) are reasonably
realistic.
www.rsTRAIL.nl
Tactical Level (1)
• Responsible for finding plans and keeping those in
line with reality
• Customers may add and remove orders, as well as
change them
• Problems that cannot be handled by the operational
planners must be dealt with at the tactical level
• Output is a list of order assignments for
each operational agent
www.rsTRAIL.nl
Tactical Level (2)
• Planning is done by means of a heuristic
function, which tells which agent should
execute an order. If no agent can be found, a
reordering is necessary
• Replanning is done by removing the affected
orders and offer them to the planner again
www.rsTRAIL.nl
Operational Level (1)
• Responsible for performing the tasks they
have been assigned
• Tactical layer may add and remove orders as
well as change them
• In the event of incidents, the operational
planner should detect these, and try to fix
within the bounds set by the tactical
layer. Incidents that cannot be dealt with,
are reported to the higher level
www.rsTRAIL.nl
Operational Level (2)
• Adaptive route planning, adapting to usage
levels of the roads. Agents will take another
route if they see a road is congested
• Traffic control at crossroads to ensure that only
one agent can make use of a crossroad. Traffic
flow is being maximized
www.rsTRAIL.nl
TPP – Transport resources
•
•
•
•
Transportation orders
Infrastructure resources
Transport resources
Agents
www.rsTRAIL.nl
TPP - Agents
•
•
•
•
Transportation orders
Infrastructure resources
Transport resources
Agents
Planners
Customers
www.rsTRAIL.nl
TPP – Agent architecture
customer agents
orders
interface,
auction mechanism
tactical agents
operational agents /
cross road agents
infrastructure
/ transport resources
www.rsTRAIL.nl