1, Experimental background

  according to the time distribution of the first operation, the elevator simulation system is realized to test the time cost performance of students arriving at the first floor in different scenarios. Elevator system is a discrete system, which is driven by events. The state changes at discrete time points and operates in the mode of call first service.

2, Known conditions

1. Arrival time is the start time = wake-up time distribution + washing time distribution. The distribution of wake-up time is N ( 7.633 , 0.7822 ) N(7.633,0.7822) N(7.633,0.7822), the distribution of washing time is N ( 0.17689 , 0.00235 ) N(0.17689,0.00235) N(0.17689,0.00235) .
2. The running speed of the elevator is 1.58s/floor.
3. Residence time of each floor U ( 10 , 60 ) U(10,60) U(10,60) seconds.
4. Elevator operation strategy: call first, service first + operation direction floor sequencing strategy

3, Implementation process

  the elevator has three states: idle, running under full load (number of people < 10), running and full load (number of people = 10). Set Event_queue is the sequence of events. The first behavior is the start time and consumption time. The second behavior is the current state. 1 is arrival, 0 is in the elevator, and - 1 determines whether to reach the first floor or out of the elevator. Let queue be the waiting sequence, and each line represents missing multiplication. The first digit is the number of people, and the second digit and later are the ID number
Set queue_ in_ The ID that the elevator records in the elevator.
There are three situations for elevator operation:

1. Students arrive to call the elevator ① yes and open door ③ whether it is full ② whether it is on the first floor.
2. When the elevator is running, arrive at the call floor, judge whether there is a queue below the call floor in turn, and if so, join the elevator queue when the elevator is running downward under the condition that the elevator is not full.
3. The elevator closes and waits for a call.

Case 1 type=1

Figure 1 student arrival flow chart

Case 2 type=0

Figure 2 flow chart of elevator movement process

Case 3 type = -1

Fig. 3 flow chart of elevator door closing waiting process

4, Effect test

Operation process:

......

Figure 4 operation process

Figure 5 broken line diagram of time consumption

Scene group comparison
① There are 20 students on each floor

Table 1 (5,9) average consumption schedule under the floor

Number of floors		5	6	7	8	9
Total number		100	120	140	160	180
Average consumption time	1	43.511s	41.365	67.589	52.908	65.652
	2	44.179s	48.702	53.102	61.904	86.502
	3	41.515	53.731	60.289	59.374	64.415
	4	41.056	49.858	60.929	53.575	71.541
	5	38.552	67.702	40.739	64.393	74.349
	Total average	41.762	52.271	56.5296	58.4308	72.4918

Figure 5 Comparison of average consumption time of different floors
② According to the actual data of the author's dormitory building, the average service time of 64 people on each floor is 261.192s
Table 2 average consumption schedule of 64 people on the 9th floor

1	2	3	4	5	average
376.576	196.350	267.617	266.110	199.309	261.192s

5, Conclusion

Compared with the average time performance, the average time cost increases with the increase of the number of floors and the total number of people.

Appendix:

Main.m

clc;clear;
close all;
%***********************
Event_queue= [];%Event queue
N=6;%Number of floors
student_num = 20*N;
queue = zeros(N,20);
elevator_loc = 1;%Elevator floor
elevator_num_threshold = 10;%Maximum number of elevators
num_in_elevator = 0;%Number of people in the elevator
time_every_floor = 0.0004388; %2.1361/3600s
elevator_dst = 0;
queue_in_elevator = [];
elevator_door = 0;%Status of elevator door

wakeup_time=normrnd(7.633,0.7822,1,student_num);
wash_time=normrnd(0.17689,0.00235,1,student_num);
t=wakeup_time+wash_time;
time=sort(t);

for t=1:student_num
    s(t)=student;
    s(t).id = t;
    s(t).StartTime = time(t);
    s(t).floor = unidrnd(N); %floor=1 2 3 4 5 6 7 8 9
    s(t).left_elevator = 0;%Time to leave the elevator
    if s(t).floor == 1
        s(t).left_elevator = s(t).StartTime;
    else
        Event_queue = insert_Event_queue(Event_queue, s(t).StartTime, 1,s(t).id);
    end
end
t_floor = []; %Print and generate the corresponding floor of students
for i = 1:student_num
    t_floor = [t_floor s(i).floor];
end
t_floor;
t_start=[]; %Print and generate the corresponding start time of students entering the elevator system
for i =1:student_num
    t_start = [t_start s(i).StartTime];
end
t_start;

t=0;
mid = 0;
while(~isempty(Event_queue))

        
    [t,type,id,Event_queue]=pop_Event_queue(Event_queue);
%**********************************************************************************************
    if type == -1 %Elevator door closing
        elevator_door = 0;
        if elevator_loc == 1 
            for i = N:-1:1
                if queue(i,1) ~= 0
                    elevator_dst = i;
                    break;
                end
            end
            if i == 1
                elevator_dst = 0;
            else
                Event_queue = insert_Event_queue(Event_queue,t+time_every_floor*(elevator_dst-1), 0, elevator_dst);
            end
        else
            time_arrive_next_floor = t + time_every_floor;%Go to the next floor
            Event_queue = insert_Event_queue(Event_queue,time_arrive_next_floor, 0, elevator_loc-1);%insert change event
        end
%**********************************************************************************************         
    elseif type == 0 %Elevator operation
       elevator_loc = id;%Elevator floor
       elevator_door = 1;
       if elevator_loc == 1%Get out of the elevator
           while(num_in_elevator ~= 0)
               temp_id = queue_in_elevator(1);
               s(temp_id).left_elevator = t;%Record the time
               queue_in_elevator = queue_in_elevator(2:length(queue_in_elevator));
               num_in_elevator = num_in_elevator - 1;
           end
%            queue_in_elevator = [];
           elevator_dst = 0;
           time_elevator_close = t + (10 + 50 * rand())/3600;
           Event_queue = insert_Event_queue(Event_queue,time_elevator_close, -1, elevator_loc);%insert close event
       elseif elevator_loc == elevator_dst
           elevator_dst = 1;
           time_elevator_close = t + (10 + 50 * rand())/3600;
           Event_queue = insert_Event_queue(Event_queue,time_elevator_close, -1, elevator_loc);%insert close event
           if queue(elevator_loc,1) ~= 0
               [queue, pop_id] = pop_queue(queue,elevator_loc,elevator_num_threshold-num_in_elevator);
                while(~isempty(pop_id))
                    temp_id = pop_id(1);
                    queue_in_elevator = [queue_in_elevator temp_id];%ID Put it in the elevator
                    num_in_elevator = num_in_elevator + 1;
                    pop_id = pop_id(2:length(pop_id));
                end
           end
       elseif elevator_dst == 1 
           if queue(elevator_loc,1) ~= 0 && num_in_elevator < elevator_num_threshold%Determine whether someone
               [queue, pop_id] = pop_queue(queue,elevator_loc,elevator_num_threshold-num_in_elevator);
                while(~isempty(pop_id))%Layer by layer judgment
                    temp_id = pop_id(1);
                    queue_in_elevator = [queue_in_elevator temp_id];
                    num_in_elevator = num_in_elevator + 1;
                    pop_id = pop_id(2:length(pop_id));
                end
                time_elevator_close = t + (10 + 50 * rand())/3600;
                Event_queue = insert_Event_queue(Event_queue,time_elevator_close, -1, elevator_loc);%insert close event
           else
                Event_queue = insert_Event_queue(Event_queue,t+time_every_floor, 0, elevator_loc-1);%insert change event
           end
      end
 %**********************************************************************************************   
    elseif type == 1% Elevator.
        if elevator_loc == s(id).floor && elevator_door == 1%The elevator is just in and the door is open
                queue_in_elevator = [queue_in_elevator id];
                num_in_elevator = num_in_elevator + 1;
        elseif queue(s(id).floor,1) == 0 %Judge whether the current floor queue is empty
            temp_num_in_queue = queue(s(id).floor,1);%Number of people on this floor
            queue(s(id).floor,temp_num_in_queue+2) = id;
            queue(s(id).floor,1) = queue(s(id).floor,1) + 1;
            if elevator_loc == 1 && elevator_dst == 0 %At first, the elevator was on the first floor
                for i = N:-1:1
                    if queue(i,1) ~= 0
                        elevator_dst = i;
                        break;
                    end
                end
                Event_queue = insert_Event_queue(Event_queue,t+time_every_floor*(elevator_dst-1), 0, elevator_dst);%hold id Changed to the floor
            end
        else %else, join the queue
            temp_num_in_queue = queue(s(id).floor,1);
            queue(s(id).floor,temp_num_in_queue+2) = id;
            queue(s(id).floor,1) = queue(s(id).floor,1) + 1;
        end
    end

end
% Graphical visualization of results
t_cost=[];
t_left=[];
for i =1:student_num
        t_cost = [t_cost (s(i).left_elevator-s(i).StartTime)*3600];
end
for i =1:student_num
    t_left = [t_left s(i).left_elevator];
end

x=(1:student_num);
figure
plot(x,t_cost,'LineWidth',1.5);
xlabel('ID');
ylabel('Time consuming(Unit: Second)');
grid on;

%Result value output
fprintf('Number of floors: %d  Total number of students:%d\n',N,student_num);
fprintf('-----------------------------------------------------------\n')
t_start_hour=floor(t_start);
t_start_middle = (t_start-floor(t_start))*60;
t_start_min=floor(t_start_middle);
t_start_second=(t_start_middle-floor(t_start_middle))*60;

t_left_hour=floor(t_left);
t_left_middle = (t_left-floor(t_left))*60;
t_left_min=floor(t_left_middle);
t_left_second=(t_left_middle-floor(t_left_middle))*60;

for k=1:student_num
       fprintf('ID be entitled as %d My students are in the second grade %d The departure time on the first floor is %d:%d:%0.1f,Departure time is %d:%d:%0.1f,time consuming%0.1fs\n',s(k).id,s(k).floor,t_start_hour(k),t_start_min(k),t_start_second(k),t_left_hour(k),t_left_min(k),t_left_second(k),t_cost(k));
end
fprintf('-----------------------------------------------------------\n')
fprintf('The average length of time students spend taking the elevator= %f second\n',mean(t_cost));

pop_queuw.m

function [ queue, pop_id ] = pop_queue( queue, index ,num_to_pop )
    pop_id = [];
    num_pop = 0;
    if queue(index,1) <= num_to_pop %The number of students who want to withdraw is less than the number of queuing on the current floor
        num_pop = queue(index,1); %Everyone in line took it out
        for i = 2:(num_pop+1)
            pop_id = [pop_id queue(index,i)];
            if queue(index,i) == 0
                bb = 1;
            end
        end
        queue(index,:) = 0;
    else %The number of students you want to withdraw is more than the number of people in the queue on the current floor
        num_pop = num_to_pop;
        queue(index,1) = queue(index,1) - num_pop;
        for i = 2:(num_pop +1)
            pop_id = [pop_id queue(index,i)];
            if queue(index,i) == 0
                bb = 1;
            end
            queue(index,i) = 0; %Dispose of the removed student position 0
        end
        for i = 2:(queue(index,1)+1)
            queue(index,i) = queue(index,i+num_pop); %Line up the students who are not taken out from the back and move forward
            queue(index,i+num_pop) = 0; %The student position moved forward is disposed of 0
        end
        
    end
end

insert_Event_queue.m

function event_queue=insert_Event_queue(event_queue,time, type,id)

if isempty(event_queue)
    event_queue = [time type id]';
else
    s = size(event_queue);
    %check the start and end 
    if event_queue(1,1) >= time
        %add to the start
        event_queue = [[time type id]' event_queue(:,1:s(2))];
    elseif event_queue(1,s(2)) <= time
        %add to the end
        event_queue = [event_queue(:,1:s(2)) [time type id]'];
    else
        for n = 1:s(2) %go through the event queue and find the right place to insert
            if event_queue(1,n)<time
                %insert the time and type
                event_queue = [event_queue(:,1:n) [time type id]' event_queue(:,n+1:s(2))];
                break;
            end
        end
    end
end

pop_Event_queue.m

function [time, type, id, event_queue]=pop_Event_queue(event_queue)
time= event_queue(1,1);% move the timer
type = event_queue(2,1);
id = event_queue(3,1);
s = size(event_queue);
if s == [3 1]% only one event existed
    event_queue = [];
else %more than one event existed
     %push the fisrt event out.
    event_queue=event_queue(:,2:s(2));%Remove the previous one            
end

reference resources
[1]. Liuss Shengsheng cabin