Elevator Control System

Build Instruction:

The simplest way to build is to clone the repository - git clone https://github.com/nobelium/elevator-control-system/ Move to source directory - cd src Compile - javac ElevatorDriver.java Run - java ElevatorDriver

(Or)

Import the project into Eclipse and click run button

Assumptions made:

• The users of the elevator On-board or Off-board the elevator as soon as the elevator reaches the floor.
• In each step function is long enough for the elevator to travel one floor

Scheduling Algorithm:

The scheduling Algorithm uses a two stage approach. This algorithm improves over the naive First-In-First-Out (FIFO) by adding a Piggyback stage. Each pickup request is checked if its possible to piggyback before its added to FIFO request queue.

Criteria for piggybacking:

The image below shows the algorithm and the type of priority queue used for each case. The First column in the image shows the direction in which the elevator is moving and the second column shows the direction of the request it is going to serve. The third column gives the criteria for piggybacking if a new pickup request is issued.

Caveats and areas of improvements:

• Does not smoothly handle the case where the user request for an elevator in one direction and enters a floor number which is in another direction
• Does not consider waiting time, velocity and blocked status for elevator
• Does not consider maximum capacity of elevator
• Does not consider number of piggyback riders/number of piggyback stops