The document describes a taxi fleet simulator called SPADE that uses agent-based modeling. It simulates different pickup strategies for taxis and passengers using agents with different states. The default strategies have taxis accept all requests, passengers accept the first request, and the coordinator delegates all requests to taxis. The document provides instructions for installing and running the simulator and defines exercises to implement new coordinator, taxi, and passenger strategies like closest taxi and dynamic closest taxi strategies.

1. SPADE
Javi Palanca

2. Goals
Simulate different pick-up
strategies for a taxi fleet
Based on agents (SPADE)
Using Agreement
Technologies
Free sandbox

3. code: https://github.com/javipalanca/taxi_simulator
doc: https://taxi-simulator.readthedocs.io
Taxi Simulator

4. Agents
TaxiAgent PassengerAgent
CoordinatorAgent
TAXI_WAITING
TAXI_WAITING_FOR_APPROVAL
TAXI_MOVING_TO_PASSENGER
TAXI_IN_PASSENGER_PLACE
TAXI_MOVING_TO_DESTINY
PASSENGER_WAITING
PASSENGER_ASSIGNED
PASSENGER_IN_TAXI
PASSENGER_IN_DEST

5. Request Protocol
TaxiAgent
PassengerAgent CoordinatorAgent
REQUEST_PERFORMATIVE
REQUEST_PERFORMATIVE
PROPOSE_PERFORMATIVE
CANCEL_PERFORMATIVE
ACCEPT_PERFORMATIVE
REFUSE_PERFORMATIVE
GOTO TRAVEL_PROTOCOL pick_up_passenger()
CANCEL_PERFORMATIVE

6. Strategy Pattern
TaxiAgent
PassengerAgent
CoordinatorAgent
TaxiStrategyBehaviour
PassengerStrategyBehaviour
CoordinatorStrategyBehaviour
def send_proposal(self, passenger_id, content=None)
def cancel_proposal(self, passenger_id, content=None)
def pick_up_passenger(self, passenger_id, origin, dest)
def send_request(self, content=None)
def accept_taxi(self, taxi_aid)
def refuse_taxi(self, taxi_aid)
def timeout_receive(self, timeout=5)
REQUEST_PROTOCOL
_process(self)
_process(self)
_process(self)

7. Install
$ pip install --user virtualenv
# Create virtual environment with python 2.7
$ virtualenv --python=`which python2.7` taxi_demo
$ cd taxi_demo/
$ source bin/activate
(taxi-demo)$
# Install taxi simulator
(taxi-demo)$ pip install taxi_simulator
# Run taxi simulator
(taxi-demo)$ taxi_simulator --help

8. Usage(taxi-demo)$ taxi_simulator --help
Usage: taxi_simulator [OPTIONS]
Console script for taxi_simulator.
Options:
-t, --taxi TEXT Taxi strategy class (default:
AcceptAlwaysStrategyBehaviour).
-p, --passenger TEXT Passenger strategy class (default:
AcceptFirstRequestTaxiBehaviour).
-c, --coordinator TEXT Coordinator strategy class (default:
DelegateRequestTaxiBehaviour).
--port INTEGER Web interface port (default: 9000).
-nt, --num-taxis INTEGER Number of initial taxis to create (default:
0).
-np, --num-passengers INTEGER Number of initial passengers to create
(default: 0).
--name TEXT Coordinator agent name (default:
coordinator).
--passwd TEXT Coordinator agent password (default:
coordinator_passwd).
-bp, --backend-port INTEGER Backend port (default: 5000).
-v, --verbose Show verbose debug.
--help Show this message and exit.

9. Run
(taxi-demo)$ taxi_simulator --port 9999
INFO:root:XMPP server running.
INFO:root:Running SPADE platform.
INFO:root:Creating 0 taxis and 0 passengers.
INFO:CoordinatorAgent:Coordinator agent running
INFO:CoordinatorAgent:Web interface running at http://127.0.0.1:9999/app
INFO:werkzeug: * Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)
Open http://127.0.0.1:9999/app

10. Default Strategies: Coordinator
class DelegateRequestTaxiBehaviour(CoordinatorStrategyBehaviour):
def _process(self):
msg = self._receive(block=True)
msg.removeReceiver(coordinator_aid)
for taxi in self.myAgent.taxi_agents.values():
msg.addReceiver(taxi.getAID())
self.myAgent.send(msg)
self.logger.debug("Coordinator sent request to taxi {}".format(taxi.getName()))

11. Default Strategies: Taxi
class AcceptAlwaysStrategyBehaviour(TaxiStrategyBehaviour):
def _process(self):
msg = self._receive(block=True)
content = json.loads(msg.getContent())
performative = msg.getPerformative()
self.logger.debug("Taxi {} received request protocol from passenger {}.".format(self.myAgent.agent_id,
content["passenger_id"]))
if performative == REQUEST_PERFORMATIVE:
if self.myAgent.status == TAXI_WAITING:
self.send_proposal(content["passenger_id"], {})
self.myAgent.status = TAXI_WAITING_FOR_APPROVAL
self.logger.debug("Taxi {} sent proposal to passenger {}.".format(self.myAgent.agent_id,
content["passenger_id"]))
elif performative == ACCEPT_PERFORMATIVE:
if self.myAgent.status == TAXI_WAITING_FOR_APPROVAL:
self.logger.debug("Taxi {} got accept from {}".format(self.myAgent.agent_id,
content["passenger_id"]))
self.pick_up_passenger(content["passenger_id"], content["origin"], content["dest"])
else:
self.cancel_proposal(content["passenger_id"], {})
elif performative == REFUSE_PERFORMATIVE:
self.logger.debug("Taxi {} got refusal from {}".format(self.myAgent.agent_id,
content["passenger_id"]))
self.myAgent.status = TAXI_WAITING

12. Default Strategies: Passenger
class AcceptFirstRequestTaxiBehaviour(PassengerStrategyBehaviour):
def _process(self):
if self.myAgent.status == PASSENGER_WAITING:
self.send_request(content={})
msg = self.timeout_receive(timeout=5)
if msg:
performative = msg.getPerformative()
if performative == PROPOSE_PERFORMATIVE:
taxi_aid = msg.getSender()
if self.myAgent.status == PASSENGER_WAITING:
self.logger.debug("Passenger {} received proposal from {}".format(self.myAgent.agent_id,
taxi_aid.getName()))
self.accept_taxi(taxi_aid)
else:
self.refuse_taxi(taxi_aid)
elif performative == CANCEL_PERFORMATIVE:
self.myAgent.status = PASSENGER_WAITING

13. Utils
def build_aid(agent_id):
return aid(name=agent_id + "@127.0.0.1", addresses=["xmpp://" + agent_id + "@127.0.0.1"])
coordinator_aid = build_aid("coordinator")
def random_position():
...
return [lat, lon]
def are_close(coord1, coord2, tolerance=10):
return vincenty(coord1, coord2).meters < tolerance
def request_path(ori, dest):
...
return path, distance, duration
from geopy import vincenty
vincenty(coord1, coord2).meters

14. Exercices
from taxi_simulator.coordinator import CoordinatorStrategyBehaviour
from taxi_simulator.passenger import PassengerStrategyBehaviour
from taxi_simulator.taxi import TaxiStrategyBehaviour
################################################################
# #
# Coordinator Strategy #
# #
################################################################
class MyCoordinatorStrategy(CoordinatorStrategyBehaviour):
def _process(self):
# Your code here
################################################################
# #
# Taxi Strategy #
# #
################################################################
class MyTaxiStrategy(TaxiStrategyBehaviour):
def _process(self):
# Your code here
################################################################
# #
# Passenger Strategy #
# #
################################################################
class MyPassengerStrategy(PassengerStrategyBehaviour):
def _process(self):
# Your code here
1. Closest taxi strategy
2. Dynamic closest taxi
strategy
(cancelling ongoing taxis)
my_strategies.py
(taxi-demo)$ taxi_simulator --port 9999 --coordinator my_strategies.MyCoordinatorStrategy
--taxi my_strategies.MyTaxiStrategy --passenger my_strategies.MyPassengerStrategy