matlab求阶跃响应性能指标函数代码

以下是一个示例MATLAB函数，用于计算阶跃响应的性能指标：

function [rise_time, settling_time, overshoot, undershoot] = step_response_metrics(y, t)
% STEP_RESPONSE_METRICS - compute performance metrics for a step response
%
% Inputs:
%   y - the step response of the system (vector)
%   t - the time vector corresponding to y (vector)
%
% Outputs:
%   rise_time - the time it takes for the response to rise from 10% to 90%
%               of its final value (scalar)
%   settling_time - the time it takes for the response to settle within
%                   5% of its final value (scalar)
%   overshoot - the maximum percentage overshoot of the response (scalar)
%   undershoot - the maximum percentage undershoot of the response (scalar)

% Find the final value of the response
final_value = y(end);

% Find the time it takes for the response to rise from 10% to 90%
rise_time_idx = find(y >= 0.1*final_value & y <= 0.9*final_value, 1);
rise_time = t(rise_time_idx);

% Find the time it takes for the response to settle within 5% of its final value
settling_range = [final_value-0.05*final_value final_value+0.05*final_value];
settling_time_idx = find(y >= settling_range(1) & y <= settling_range(2), 1, 'last');
settling_time = t(settling_time_idx);

% Find the maximum overshoot and undershoot of the response
overshoot = max((y - final_value)/final_value) * 100;
undershoot = min((y - final_value)/final_value) * 100;

该函数接受两个输入参数：阶跃响应的向量y和相应的时间向量t。输出四个性能指标：上升时间，稳定时间，最大超调量和最大欠调量。该函数使用MATLAB内置函数和常规算术运算确定这些指标。