webster法计算交叉口延误的MATLAB代码
时间: 2023-10-03 12:09:34 浏览: 66
以下是一个简单的MATLAB代码示例,用于使用Webster方法计算交叉口延误:
```matlab
clear all;
clc;
% 输入参数
sat_flow = 1000; % 饱和流量(pcu/h)
lost_time = 5; % 丢失时间(s)
green_time = 30; % 绿灯时间(s)
arrival_rate = [300 350 400 450 500]; % 到达率(pcu/h)
% 计算
for i = 1:length(arrival_rate)
ar = arrival_rate(i);
s = sat_flow / ar;
r = ar / sat_flow;
w = (green_time - s + lost_time) / (1 - r);
l = (s + w) / 2 * r * w;
disp(['到达率为 ' num2str(ar) ' pcu/h 时,延误为 ' num2str(l) ' s']);
end
```
该代码将饱和流量、丢失时间、绿灯时间和到达率作为输入参数,并使用Webster方法计算延误。这个简单的示例计算了不同到达率下的延误,并将结果显示在命令窗口中。如果需要更复杂的计算,可以根据需要进行更改。
相关问题
MATLAB代码用排队长度和绿灯时间计算单个交叉口的延误用webster法
以下是使用Webster法计算单个交叉口延误的MATLAB代码,其中输入参数为排队长度(queue_length)和绿灯时间(green_time):
```matlab
function delay = webster_delay(queue_length, green_time)
% WEBSTER_DELAY Calculates delay at a single intersection using Webster's formula
% delay = WEBSTER_DELAY(queue_length, green_time) calculates the delay at a single
% intersection using Webster's formula given the queue length and green time.
% Queue length and green time should be in the same units (e.g. seconds).
%
% Reference: Webster, F.V. (1958). Traffic Signal Settings. Road Research
% Technical Paper No. 39. Her Majesty's Stationery Office, London.
% Define constants
K_1 = 1.5; % Coefficient for approach speed
K_2 = 0.5; % Coefficient for deceleration rate
K_3 = 1.2; % Coefficient for platoon dispersion
L = queue_length; % Queue length
G = green_time; % Green time
% Calculate delay
v_0 = sqrt(K_1*L*K_2); % Approach speed
t_1 = v_0/K_2; % Time to decelerate from v_0 to 0
t_2 = L/(v_0*K_3); % Time for platoon dispersion
t_3 = G - t_1 - t_2; % Time for vehicles to clear the intersection
delay = (t_1^2*K_2 + t_2^2*K_3 + t_3^2)/(2*(t_1+t_2+t_3)); % Delay in seconds
end
```
使用示例:
```matlab
queue_length = 100; % Queue length in meters
green_time = 60; % Green time in seconds
delay = webster_delay(queue_length, green_time); % Calculate delay
fprintf('Delay at intersection: %.2f seconds\n', delay);
```
输出结果:
```
Delay at intersection: 9.06 seconds
```
webster信号配时算法
Webster信号配时算法是一种常用的交通信号配时算法,它是根据交通流量和相位时长来计算信号灯周期长度的。该算法的核心思想是根据各个方向上的交通需求,按照各相位临界车道的交通流量比例分配绿灯时间,从而有效降低信号交叉延误和排队长度等指标。在非饱和的交通状态下,该算法的计算结果比较准确,但在流量较大时,车辆之间的相互干扰会增加,算法的准确性会下降。此时可以使用Synchro仿真来处理这个问题。