Pluribus: final – Group A Ingmar, Laurence, Kang, Raymon and Roy

Component architecture Bus Unit

Introducing types Instances of the following types are unique: Bus ID Bus Stand ID Time is expressed in UTC

Sender and Receiver The input of a Sender matches it’s output Output of the Sender may be delayed for buffering The input of a Receiver matches it’s output Each Sender has a reference to a Receiver The input of a Sender matches the output of it’s connected Receiver The Sender initiates the connection to the Receiver Other entities need not be aware of the communication mechanism used

Bus Unit Given: Bus ID Input: Signal from the GPS unit Output: GPS coordinates GPS time in UTC Bus ID

R&S Aware System Given: A graph Map with nodes of type Node the nodes contain GPS coordinates and the edges contain the average travelling speed and the distance A set Routes of sequences of (Node, Time) For each Route also a relation Node to Stand ID. Each node that is not a bus stand has Stand ID null Each node that is a bus stand has the Stand ID of the bus stand Threshold t

R&S Aware System (2) State: Set I of (GPS coordinates, GPS time in UTC, Bus ID) A set of sequences ETAs of (Node, Time) one sequence of ETAs for each bus. Initialisation: Sequence I as an empty sequence Set of sequences ETAs as Routes (initial timetable) Updating state after receiving the input: I = I \ (_,_, bid) U (coords,time,bid) Update ETAs for bid, if and only if the difference is at least t

R&S Aware System (3) Input: GPS coordinates coords GPS time in UTC time Bus ID bid Output: Either: Bus ID bid, Line number nr, and Sequence times of (Stand ID, Time) Or no output at all

R&S Aware System (4) Calculating Output: Using the Bus ID and current time, get the Line number nr and Route the bus is following Position p are the coords mapped to the most likely position where the bus is at on an edge on the graph

R&S Aware System (5) Calculating Output: For each Node in the current Route after p, calculate a Time by the remaining distance from p to that Node following the current Route, using the average traveling speed In Sequence times only include the Nodes that have Stand ID not equal to null Sequence times only contains tuples (Stand ID, Time) for which the new time differs from the old time enough. If sequence times is empty, then there is no output at all.

Dispatcher Given: A relation P, being a subset of (Stand ID,Phone number) Input: Bus ID bid, Line number nr, and Sequence times of (Stand ID, Time) Output: For each element (sid, time) of times, send a message to (P sid), using the appropriate Sender, containing: bid nr time

Bus Stand Given: A static set S, being a subset of (Bus ID, Line number, Time) defining the original schedule A set D, also being a subset of (Bus ID, Line number, Time) initially the same as S Local Time Zone Input: Bus ID bid, Line number nr, and Time time Result: D = D \ (bid,nr,_) U (bid,nr,time)

Bus Stand Display Every interval i: Update the display information, such that it contains n elements, such that the n th element on the display is the n th element of D ordered by time, larger than the current time in UTC For each element to display, display: Line number Time in local time zone