A brief introduction to elevator scheduling algorithm

0x00 Overview

Based on the structure of bus algorithm, this algorithm increases the judgment of docking in the middle floor and the search of a stop at the top and bottom.

1. If the elevator is at the top level, traverse all requests in the request queue, logging in the direction of the operation: most recent same-direction external request, nearest same-direction internal request, furthest counter-directional external request;

When scheduling, increase the elevator is full of judgment, if full, only to meet internal requests, the next stop is the closest in the same direction internal request; If the elevator is not full, while there are external requests in the same direction and internal requests docked in the nearest request floor, there is no same direction request when docked in the furthest side to the external request floor;

At the bottom of the same time;

2. In the middle of the floor, determine whether the next stop is open and close, conditions including whether it is full, whether there is a request on the floor;

The uniqueness of the 0x01 algorithm:

I. Relative to the bus algorithm, the flexible use of known information (including request information, elevator capacity, the remaining space and other state information), reducing unnecessary time to dock the switch door;

II. Since each trip is as high priority as possible to solve the same direction of the request, the entire scheduling process will not exist a passenger waiting for a long time (up to the time of the trip), so the practicality of the design is excellent, this is the bus algorithm learning and reference;

Iii. the strategy of not stopping when the elevator is full is closer to reality, reducing a lot of overload rejection, can greatly improve the efficiency of elevator dispatching operation during rush hour.

A brief introduction to elevator scheduling algorithm