MATLAB一阶系统二阶系统伯德图和奈氏图

MATLAB可以用系统工具箱中的函数来绘制伯德图和奈氏图。这里简要介绍一下如何使用MATLAB绘制一阶和二阶系统的伯德图和奈氏图。

一阶系统

伯德图：

num = 1;
den = [1 1];
G = tf(num, den);
bode(G);
grid on;

奈氏图：

num = 1;
den = [1 1];
G = tf(num, den);
nyquist(G);
grid on;

二阶系统

伯德图：

num = 1;
den = [1 0.2 1];
G = tf(num, den);
bode(G);
grid on;

奈氏图：

num = 1;
den = [1 0.2 1];
G = tf(num, den);
nyquist(G);
grid on;

需要注意的是，这里的num和den分别是系统的分子和分母多项式系数，可以根据具体的系统进行修改。

相关问题

MATLAB一阶系统二阶系统伯德图和奈氏图通过gui实现

可以使用MATLAB中的GUI开发工具来实现一阶系统和二阶系统的伯德图和奈氏图，下面是一个简单的实现示例：

首先，创建一个GUI窗口，可以使用MATLAB的GUIDE工具进行创建，将窗口分为两个部分，一部分用于输入系统参数，另一部分用于显示伯德图和奈氏图。

在输入部分，可以添加编辑框或下拉菜单等控件，用于用户输入系统参数，如系统的阻尼比、自然频率等。

在显示部分，可以添加绘图区域，用于绘制伯德图和奈氏图。使用MATLAB的绘图函数，如bode、nyquist等，可以方便地绘制伯德图和奈氏图。

下面是一个简单的示例代码：

function varargout = system_gui(varargin)
% SYSTEM_GUI MATLAB code for system_gui.fig
%      SYSTEM_GUI, by itself, creates a new SYSTEM_GUI or raises the existing
%      singleton*.
%
%      H = SYSTEM_GUI returns the handle to a new SYSTEM_GUI or the handle to
%      the existing singleton*.
%
%      SYSTEM_GUI('CALLBACK',hObject,eventData,handles,...) calls the local
%      function named CALLBACK in SYSTEM_GUI.M with the given input arguments.
%
%      SYSTEM_GUI('Property','Value',...) creates a new SYSTEM_GUI or raises the
%      existing singleton*.  Starting from the left, property value pairs are
%      applied to the GUI before system_gui_OpeningFcn gets called.  An
%      unrecognized property name or invalid value makes property application
%      stop.  All inputs are passed to system_gui_OpeningFcn via varargin.
%
%      *See GUI Options on GUIDE's Tools menu.  Choose "GUI allows only one
%      instance to run (singleton)".
%
% See also: GUIDE, GUIDATA, GUIHANDLES

% Edit the above text to modify the response to help system_gui

% Last Modified by GUIDE v2.5 23-Jun-2021 17:37:59

% Begin initialization code - DO NOT EDIT
gui_Singleton = 1;
gui_State = struct('gui_Name',       mfilename, ...
                   'gui_Singleton',  gui_Singleton, ...
                   'gui_OpeningFcn', @system_gui_OpeningFcn, ...
                   'gui_OutputFcn',  @system_gui_OutputFcn, ...
                   'gui_LayoutFcn',  [] , ...
                   'gui_Callback',   []);
if nargin && ischar(varargin{1})
    gui_State.gui_Callback = str2func(varargin{1});
end

if nargout
    [varargout{1:nargout}] = gui_mainfcn(gui_State, varargin{:});
else
    gui_mainfcn(gui_State, varargin{:});
end
% End initialization code - DO NOT EDIT


% --- Executes just before system_gui is made visible.
function system_gui_OpeningFcn(hObject, eventdata, handles, varargin)
% This function has no output args, see OutputFcn.
% hObject    handle to figure
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
% varargin   command line arguments to system_gui (see VARARGIN)

% Choose default command line output for system_gui
handles.output = hObject;

% Update handles structure
guidata(hObject, handles);

% UIWAIT makes system_gui wait for user response (see UIRESUME)
% uiwait(handles.figure1);


% --- Outputs from this function are returned to the command line.
function varargout = system_gui_OutputFcn(hObject, eventdata, handles) 
% varargout  cell array for returning output args (see VARARGOUT);
% hObject    handle to figure
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Get default command line output from handles structure
varargout{1} = handles.output;


% --- Executes on button press in plot_button.
function plot_button_Callback(hObject, eventdata, handles)
% hObject    handle to plot_button (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% read input values
zeta = str2double(get(handles.zeta_edit, 'String'));
wn = str2double(get(handles.wn_edit, 'String'));

% calculate system parameters
wd = wn * sqrt(1 - zeta^2);
tau = 1 / (zeta*wn);
sys = tf(wn^2, [1, 2*zeta*wn, wn^2]);

% plot bode diagram
axes(handles.bode_axes);
bode(sys);

% plot nyquist diagram
axes(handles.nyquist_axes);
nyquist(sys);


function zeta_edit_Callback(hObject, eventdata, handles)
% hObject    handle to zeta_edit (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)


% --- Executes during object creation, after setting all properties.
function zeta_edit_CreateFcn(hObject, eventdata, handles)
% hObject    handle to zeta_edit (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    empty - handles not created until after all CreateFcns called

% Hint: edit controls usually have a white background on Windows.
%       See ISPC and COMPUTER.
if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))
    set(hObject,'BackgroundColor','white');
end


function wn_edit_Callback(hObject, eventdata, handles)
% hObject    handle to wn_edit (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)


% --- Executes during object creation, after setting all properties.
function wn_edit_CreateFcn(hObject, eventdata, handles)
% hObject    handle to wn_edit (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    empty - handles not created until after all CreateFcns called

% Hint: edit controls usually have a white background on Windows.
%       See ISPC and COMPUTER.
if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))
    set(hObject,'BackgroundColor','white');
end


% --- Executes on button press in clear_button.
function clear_button_Callback(hObject, eventdata, handles)
% hObject    handle to clear_button (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% clear plots
axes(handles.bode_axes);
cla;
axes(handles.nyquist_axes);
cla;


% --- Executes on button press in exit_button.
function exit_button_Callback(hObject, eventdata, handles)
% hObject    handle to exit_button (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% close the GUI window
close(handles.figure1);

这个示例代码可以实现通过GUI界面输入系统参数，绘制一阶系统和二阶系统的伯德图和奈氏图。