Class: ECE575 of Fall 2006
Lecturer: Moon Ho Hwang, Ph.D. (email: [email protected])
Assigned Date: 10/02/06
Due Date: Depending on each problem.
Homework 3:
Simulation of DEVS Models using ODEVS-C++ (45 points)
P1. Simulation of Atomic DEVS model of homework#2 (15 points; Due Date: 11:59 PM.
10/07/06 Sat.)
By deriving from Atomic class of ODEVS-C++ library, develop a concrete class of a
crossroad controller which has been introduced in homework #2. Simulate it s behavior to make
sure that the model satisfies the requirements addressed in homework#2.
P2. Simulation of DEVS Network of a monorail system (30 points; Due Date: 11:59 PM.
10/12/06 Thu.)
[System and its Modeling] Figure 1. illustrates the configuration of a monorail system which
consists of 4 stations whose names are ST0, ST1, ST2 and ST3, respectively. Each station is an
instance of Station class which is suppose to be a derived class of the atomic DEVS, and to
have an input event set X = {?vehicle, ?pull} and an output event set Y={!vehicle, !pull}. A state
of the station is presented by the cross production of (1) phase {Empty (E), Loading (L),
Sending (S), Pulling (P), Waiting (W), Collided (C)} and (2) the other variable nso
{false(f), true(t)} which is indicating that “next station is occupied” if nso = t, or
not, otherwise.
Figure 1. Network Diagram of Monorail System
Figure 2. illustrates the phase transition diagram of the station in which
(1) a node represents a phase and its life time. (Notice that loading time of station 1 is longer
than that of other stations s.t. lt=30 for ST1, lt=10 for STi, i{0,2,3})
(2) an arc shows its enabling pre-condition and post-condition of a state transition such that
if (?input_event & pre-conditions of non-phase variables),(post-conditions of non-phase
variables & !output_event);
ST0 ST1
ST2ST3
!vehicle
?pull !pull
?vehicle
?vehicle
!vehicle
!vehicle
?vehicle
!vehicle?vehicle
!pull
?pull
?pull
!pull
!pull ?pull
