MATLAB调试记录

安装地址

安装地址

示波器

• 显示工具栏：

set(0,‘ShowHiddenHandles’,‘On’)
set(gcf,‘menubar’,‘figure’)

• 操作工具栏，点击对应位置，编辑属性（可添加title，legend，颜色以及line设置）

导纳控制框图

• 关注参考轨迹设定，环境位置

S函数

直接馈通辨析
书写参考

>> type sfuntmpl

function [sys,x0,str,ts,simStateCompliance] = sfuntmpl(t,x,u,flag)
%SFUNTMPL General MATLAB S-Function Template
%   With MATLAB S-functions, you can define you own ordinary differential
%   equations (ODEs), discrete system equations, and/or just about
%   any type of algorithm to be used within a Simulink block diagram.
%
%   The general form of an MATLAB S-function syntax is:
%       [SYS,X0,STR,TS,SIMSTATECOMPLIANCE] = SFUNC(T,X,U,FLAG,P1,...,Pn)
%
%   What is returned by SFUNC at a given point in time, T, depends on the
%   value of the FLAG, the current state vector, X, and the current
%   input vector, U.
%
%   FLAG   RESULT             DESCRIPTION
%   -----  ------             --------------------------------------------
%   0      [SIZES,X0,STR,TS]  Initialization, return system sizes in SYS,
%                             initial state in X0, state ordering strings
%                             in STR, and sample times in TS.
%   1      DX                 Return continuous state derivatives in SYS.
%   2      DS                 Update discrete states SYS = X(n+1)
%   3      Y                  Return outputs in SYS.
%   4      TNEXT              Return next time hit for variable step sample
%                             time in SYS.
%   5                         Reserved for future (root finding).
%   9      []                 Termination, perform any cleanup SYS=[].
%
%
%   The state vectors, X and X0 consists of continuous states followed
%   by discrete states.
%
%   Optional parameters, P1,...,Pn can be provided to the S-function and
%   used during any FLAG operation.
%
%   When SFUNC is called with FLAG = 0, the following information
%   should be returned:
%
%      SYS(1) = Number of continuous states.
%      SYS(2) = Number of discrete states.
%      SYS(3) = Number of outputs.
%      SYS(4) = Number of inputs.
%               Any of the first four elements in SYS can be specified
%               as -1 indicating that they are dynamically sized. The
%               actual length for all other flags will be equal to the
%               length of the input, U.
%      SYS(5) = Reserved for root finding. Must be zero.
%      SYS(6) = Direct feedthrough flag (1=yes, 0=no). The s-function
%               has direct feedthrough if U is used during the FLAG=3
%               call. Setting this to 0 is akin to making a promise that
%               U will not be used during FLAG=3. If you break the promise
%               then unpredictable results will occur.
%      SYS(7) = Number of sample times. This is the number of rows in TS.
%
%
%      X0     = Initial state conditions or [] if no states.
%
%      STR    = State ordering strings which is generally specified as [].
%
%      TS     = An m-by-2 matrix containing the sample time
%               (period, offset) information. Where m = number of sample
%               times. The ordering of the sample times must be:
%
%               TS = [0      0,      : Continuous sample time.
%                     0      1,      : Continuous, but fixed in minor step
%                                      sample time.
%                     PERIOD OFFSET, : Discrete sample time where
%                                      PERIOD > 0 & OFFSET < PERIOD.
%                     -2     0];     : Variable step discrete sample time
%                                      where FLAG=4 is used to get time of
%                                      next hit.
%
%               There can be more than one sample time providing
%               they are ordered such that they are monotonically
%               increasing. Only the needed sample times should be
%               specified in TS. When specifying more than one
%               sample time, you must check for sample hits explicitly by
%               seeing if
%                  abs(round((T-OFFSET)/PERIOD) - (T-OFFSET)/PERIOD)
%               is within a specified tolerance, generally 1e-8. This
%               tolerance is dependent upon your model's sampling times
%               and simulation time.
%
%               You can also specify that the sample time of the S-function
%               is inherited from the driving block. For functions which
%               change during minor steps, this is done by
%               specifying SYS(7) = 1 and TS = [-1 0]. For functions which
%               are held during minor steps, this is done by specifying
%               SYS(7) = 1 and TS = [-1 1].
%
%      SIMSTATECOMPLIANCE = Specifices how to handle this block when saving and
%                           restoring the complete simulation state of the
%                           model. The allowed values are: 'DefaultSimState',
%                           'HasNoSimState' or 'DisallowSimState'. If this value
%                           is not speficified, then the block's compliance with
%                           simState feature is set to 'UknownSimState'.


%   Copyright 1990-2010 The MathWorks, Inc.

%
% The following outlines the general structure of an S-function.
%
switch flag,

  %%%%%%%%%%%%%%%%%%
  % Initialization %
  %%%%%%%%%%%%%%%%%%
  case 0,
    [sys,x0,str,ts,simStateCompliance]=mdlInitializeSizes;

  %%%%%%%%%%%%%%%
  % Derivatives %
  %%%%%%%%%%%%%%%
  case 1,
    sys=mdlDerivatives(t,x,u);

  %%%%%%%%%%
  % Update %
  %%%%%%%%%%
  case 2,
    sys=mdlUpdate(t,x,u);

  %%%%%%%%%%%
  % Outputs %
  %%%%%%%%%%%
  case 3,
    sys=mdlOutputs(t,x,u);

  %%%%%%%%%%%%%%%%%%%%%%%
  % GetTimeOfNextVarHit %
  %%%%%%%%%%%%%%%%%%%%%%%
  case 4,
    sys=mdlGetTimeOfNextVarHit(t,x,u);

  %%%%%%%%%%%%%
  % Terminate %
  %%%%%%%%%%%%%
  case 9,
    sys=mdlTerminate(t,x,u);

  %%%%%%%%%%%%%%%%%%%%
  % Unexpected flags %
  %%%%%%%%%%%%%%%%%%%%
  otherwise
    DAStudio.error('Simulink:blocks:unhandledFlag', num2str(flag));

end

% end sfuntmpl

%
%=============================================================================
% mdlInitializeSizes
% Return the sizes, initial conditions, and sample times for the S-function.
%=============================================================================
%
function [sys,x0,str,ts,simStateCompliance]=mdlInitializeSizes

%
% call simsizes for a sizes structure, fill it in and convert it to a
% sizes array.
%
% Note that in this example, the values are hard coded.  This is not a
% recommended practice as the characteristics of the block are typically
% defined by the S-function parameters.
%
sizes = simsizes;

sizes.NumContStates  = 0;
sizes.NumDiscStates  = 0;
sizes.NumOutputs     = 0;
sizes.NumInputs      = 0;
sizes.DirFeedthrough = 1;
sizes.NumSampleTimes = 1;   % at least one sample time is needed

sys = simsizes(sizes);

%
% initialize the initial conditions
%
x0  = [];

%
% str is always an empty matrix
%
str = [];

%
% initialize the array of sample times
%
ts  = [0 0];

% Specify the block simStateCompliance. The allowed values are:
%    'UnknownSimState', < The default setting; warn and assume DefaultSimState
%    'DefaultSimState', < Same sim state as a built-in block
%    'HasNoSimState',   < No sim state
%    'DisallowSimState' < Error out when saving or restoring the model sim state
simStateCompliance = 'UnknownSimState';

% end mdlInitializeSizes

%
%=============================================================================
% mdlDerivatives
% Return the derivatives for the continuous states.
%=============================================================================
%
function sys=mdlDerivatives(t,x,u)

sys = [];

% end mdlDerivatives

%
%=============================================================================
% mdlUpdate
% Handle discrete state updates, sample time hits, and major time step
% requirements.
%=============================================================================
%
function sys=mdlUpdate(t,x,u)

sys = [];

% end mdlUpdate

%
%=============================================================================
% mdlOutputs
% Return the block outputs.
%=============================================================================
%
function sys=mdlOutputs(t,x,u)

sys = [];

% end mdlOutputs

%
%=============================================================================
% mdlGetTimeOfNextVarHit
% Return the time of the next hit for this block.  Note that the result is
% absolute time.  Note that this function is only used when you specify a
% variable discrete-time sample time [-2 0] in the sample time array in
% mdlInitializeSizes.
%=============================================================================
%
function sys=mdlGetTimeOfNextVarHit(t,x,u)

sampleTime = 1;    %  Example, set the next hit to be one second later.
sys = t + sampleTime;

% end mdlGetTimeOfNextVarHit

%
%=============================================================================
% mdlTerminate
% Perform any end of simulation tasks.
%=============================================================================
%
function sys=mdlTerminate(t,x,u)

sys = [];

% end mdlTerminate
>> 

离散系统仿真

c2d函数

把传递函数离散化
dsys=c2d(sys,ts,‘method’);传函离散
[num,den]=tfdata(dsys,‘v’); 离散后提取分子分母
这里面的method有好多种,
zoh 零阶保持， 假设控制输入在采样周期内为常值，为默认值。
foh 一阶保持器，假设控制输入在采样周期内为线性。
tustin 采用双线性逼近。method用tustin替代
matched 采用SISO系统的零极点匹配法

---

采样时间

对于simulink模型，里面所有的信息都是按时间进行传递的，那么就得定义一个更新信息的时间间隔，这就是所谓的模块采样时间，其中0代表连续采样，-1代表继承所在子系统采样时间或者是系统采样时间，正数代表离散的采样时间。另外，还需注意模块的sample time必须是系统stepsize的整数倍，否则会报错的。

Matlab

入门

• 学习MATLAB桌面和窗口，指令格式，数据格式，数据mat文件和变量管理，数值数组及其运算，字符串，元胞和结构等数据类型
• 可打开指令历史窗口查看历史指令
• HOME工具条:最常用的工具栏和菜单
• PLOT:作图
• APPS：应用程序的交互式计算工具（depend on安装的工具箱）
  

技巧

• 分号表示取消输出，。。。表示续行（三点前有空格）
• 可使用箭头键来调出历史指令
• 数据显示格式（format），更改不影响计数精度（MATLAB计数精度约为16位十进制有效数字）
• 预定义变量i,j,pi,eps,realmin,realmax,Inf,NaN，不包括自然常数e，可重新赋值
• 变量区分大小写
• ans是一个特别的变量名，但运算结果未赋值给任意变量，则ans存放答案
• 查询变量（whos,who）
• 保存数据值在MAT文件(二进制数据文件)中，然后加载数据 load xxx.mat
• 可导入其他类型外部数据文件，包括TXT,EXCEL,图像文件

数组及运算

输入数组

• MATLAB基本数据单元是无需预先指定维数的数组
• 最常用的数组为双精度数值数组，数组分为一维数组和二维数组
• 数组可从工作空间打开，进而编辑，当然也可先用Excel写好，复制粘贴到变量中
• 索引即编址从1开始
• 二维数组若按照单下标方式编址，则其按列的顺序组织为一维数组（排为列向量）

b = 0:3:10;
b = linspace(0,10,4);%区间分为3份

• 数组的部分元素可按其编址提取和拼接

b([1,end])
a(1)
a(
a([1 3],[2 3])
a(2,1:3)
a(2,:)
[a:d] %数组拼接

• sum等简单统计函数对一维数组是通常意义的运算，而二维数组是按列进行（各列分别进行，返回向量）

数组运算

• 数组运算也称为点运算，即对应元素之间的运算，区分数学意义上的运算
• k + A等价于 k * ones(size(A)) + A,乘法，除法，乘方同理
• 数组的数学函数，关系和逻辑运算也按每个元素运算，如sin等（❤）
• 关系和逻辑运算要求两个操作对象具有相同的尺寸或其中一个为标量,此时类比k + A（非0为真，即1）

abs(A) >=2

高维数组

• 行列页，类比低维数组

字符串，元胞和结构

数据类型包括：数值（常用的为double），逻辑，字符，元胞，结构，由此进一步组成字符数组，元胞数组和结构数组

字符串

• 单引号标识，数据类型为字符数组(一个中文为一个字符）
• 字符串拼接：a = [a1,’.’,a2,’.’]
• 可与ASCII码互换
• 数字字符串与数值间用num2str和str2num转换，数值要转换为字符串才可以和其他字符串出现在同一数组中
• MATLAB指令可定义为一个字符串，然后使用eval来执行该指令

cell/structure

• 一般数组要求数据结构整齐，即数值和字符不能混合，尺寸相符等
• 不等长的字符串可也通过char，str2mat等来实现，这些函数会自动将较短字符串添加空格来匹配

a = char(‘haha’,‘second’)

• 要想强行匹配，引入元胞数组

a = {‘first’;1:3}; b={‘second’;[1 2;3 4]}
ab = [a,b]

• 结构通过域来定义，比元胞更丰富，灵活，组成结构数组的结构要求域名一致
• 元胞数组和结构数组转换：struct2cell和cell2struct

绘图和程序设计方法

程序结构（控制流）

• MATLAB控制流语法以end结尾
• error(字符串)：提示错误
• pause(n):暂停N秒
• switch语句/

for n:1:100
s = s +1/n/n;
end
while n <= 100
s = s +1/n/n;
n = n + 1;
end

if a,
b;
elseif c,
d;
else,
e;
end

• Ctrl+C:强行中断程序

脚本文件和函数文件(函数句柄和匿名函数)

• 函数文件能进行参数传递，格式：function[ …] = name(…) ，调用时使用其所在的文件名，而不是函数名，当然一般保持一致
• 脚本文件运行时直接输入文件名，不需.m
• M函数除了直接用其函数名来调用外，还能作为一个参数那样调用（函数handle方式）

fname = @ function_name;fname(5000)

• M函数文件中的所有变量默认为局部变量，不进入workspace，脚本文件中所有变量在执行后进入工作空间，即global变量（？）

• M函数的参数值传递主要通过其输入输出变量，但也可以用global定义global变量，其意义与工作空间变量不同，只对有定义的环境起作用

• nargin表示函数的输入变量个数，nargout为输出变量个数，varargin表示可变输入输出变量的个数

• M函数可使用子函数和嵌套函数，第一个function为主函数，其他为子函数，子函数只能被同一文件中的其他函数调用。至于嵌套函数，其在一个函数体内部，这是每个函数体要用end标志结束（具体见实例P29，展示子函数和嵌套函数及global变量）

• 修改后保存再执行，默认保存在当前文件夹中或在MATLAB的Path中

• 变量名区分大小写，而文件名不区分大小写

• 编辑器窗口（包含editor工具条）
  

• 匿名函数

fname = @(m) sum(1./(1:m).^k)
fname(5000)

• disp/input以及tic/toc
• 好的M程序文件少用循环，多用数组运算和内部函数，数组虽然不需要预定义尺寸，但可通过预分配提高运算速度
• funtool:函数分析界面

绘图

plot(x1,y1,x2,y2) %均为向量形式
fplot(fun,[a,b]) %fun用匿名函数形式
plot3(x,y,z)
plot(x,y,’:ro’)
mesh(x,y,z) %绘制曲面图形

• 图像窗口的复制图像选项（相见恨晚）
• 三维空间图可调整视角
• 图像说明和定制