Controle Digital
5 figura(s) nesta categoria. Fonte em figuras/controle-digital/.
Amostrador ideal
Chave amostradora que converte um sinal contínuo r(t) num sinal amostrado r*(kTs).
Ver código TikZ
\begin{tikzpicture}[scale=1.5, every node/.style={font=\normalsize}]
% Input signal line
\draw[line width=2pt] (0,0) -- (1.6,0);
\node[below=0.35cm] at (0.8,0) {Sinal};
\node[below=0.8cm] at (0.8,0) {contínuo};
\node[left] at (0,0) {$r(t)$};
% Left terminal (contact point)
\draw[line width=1.5pt, fill=white] (1.7,0) circle (3pt);
% Switch arm (chave) - diagonal open
\draw[line width=1.5pt] (1.7,0) -- (2.6,0.6);
% Right terminal (contact point)
\draw[line width=1.5pt, fill=white] (2.9,0) circle (3pt);
% Output signal line
\draw[line width=2pt] (3.0,0) -- (4.6,0);
\node[below=0.35cm] at (3.8,0) {Sinal};
\node[below=0.8cm] at (3.8,0) {amostrado};
\node[right] at (4.6,0) {$r^*(kT_s)$};
\end{tikzpicture}
Malha de Controle com Sinal Amostrado
Diagrama de blocos de uma malha de controle digital destacando o amostrador entre o controlador discreto e a planta contínua.
Ver código TikZ
\begin{tikzpicture}[
auto,
node distance=1.5cm,
block/.style={draw, fill=blue!5, rectangle, minimum height=1.2cm, minimum width=2.2cm, align=center, thick},
block_ctrl/.style={draw, fill=green!5, rectangle, minimum height=1.2cm, minimum width=2.2cm, align=center, thick},
sum/.style={draw, circle, minimum size=0.5cm, thick},
arrow/.style={-Stealth, thick},
dot/.style={fill, circle, minimum size=3pt, inner sep=0pt},
every node/.style={font=\small}
]
% --- Nós ---
\node (input) {};
\node [sum, right=0.8cm of input] (sum) {};
\node [block_ctrl, right=of sum] (controller) {Controlador};
\node [block, right=of controller] (interpolator) {Interpolador};
\node [block, right=1.5cm of interpolator] (plant) {Planta};
\node [right=1.2cm of plant] (output) {};
% --- Caminho Direto ---
\draw [arrow] (input) -- node {$r(nT_s)$} (sum);
\draw (sum.north east) -- (sum.south west);
\draw (sum.north west) -- (sum.south east);
\draw [arrow] (sum) -- node {$e(nT_s)$} (controller);
\draw [arrow] (controller) -- node {$u(nT_s)$} (interpolator);
\draw [arrow] (interpolator) -- node {$\bar{u}(t)$} (plant);
\draw [arrow] (plant) -- node [pos=0.6] (c_node) {$y(t)$} (output);
% --- Realimentação ---
\node [dot] at ($(plant.east)!0.5!(output)$) (branch) {};
% Desce da ramificação
\draw [thick] (branch) |- ++(0,-1.5) coordinate (corner);
% Linha horizontal até a chave
\draw [thick] (corner) -- ++(-1.2,0) coordinate (sampler_tip);
% Chave (amostrador) com T_s (sem a seta curva)
\draw [thick] (sampler_tip) -- ++(-0.5,0.4) node[above left] {$T_s$};
% O fechamento:
\draw [arrow] ($(sampler_tip)+(-0.6,0)$) -| (sum.south)
node[pos=0.9, left] {\textbf{--}};
% --- Containers (Medidas Originais) ---
\draw [dashed, thick] ($(sum.north west)+(-1.0,0.9)$) rectangle ($(interpolator.south east)+(0.35,-1.5)$);
\draw [dotted, thick] ($(controller.north east)+(1.25,0.49)$) -- ($(controller.south east)+(1.25,-1.5)$);
% Rótulos
\node [anchor=south west] at ($(sum.north west)+(-0.8,-2.3)$) {\textbf{Computador}};
\node [anchor=north west] at ($(controller.south east)+(1.7,-0.95)$) {\textbf{Interface}};
\end{tikzpicture}
Malha de Controle Digital
Diagrama de blocos de malha fechada com controlador e planta discretos, no domínio Z.
Ver código TikZ
\begin{tikzpicture}[
auto,
% Distância padrão entre os nós para compactar
node distance=1.6cm,
% Estilo padrão para blocos (Planta)
block/.style={draw, fill=blue!5, rectangle, minimum height=1.2cm, minimum width=2.2cm, align=center, thick},
% Estilo específico para o Controlador (cor diferente)
block_ctrl/.style={draw, fill=green!5, rectangle, minimum height=1.2cm, minimum width=2.2cm, align=center, thick},
% Estilo para o ponto de soma (menor)
sum/.style={draw, circle, minimum size=0.5cm, thick},
% Estilo para as setas
arrow/.style={-Stealth, thick},
% Ponto de derivação
dot/.style={fill, circle, minimum size=3pt, inner sep=0pt},
% Define o tamanho da fonte padrão para os rótulos
every node/.style={font=\small}
]
% --- Nós ---
\node (input) {};
% Aproximei o ponto de soma da entrada
\node [sum, right=0.8cm of input] (sum) {};
% Controlador (usando o estilo block_ctrl)
\node [block_ctrl, right=of sum] (controller) {Controlador \\ $C(z)$};
% Planta
\node [block, right=of controller] (plant) {Planta \\ $G(z)$};
% Reduzi o tamanho da seta de saída para compactar
\node [right=1.8cm of plant] (output) {};
% --- Caminho Direto ---
% Removido o nó que continha o sinal de "+" na entrada
\draw [arrow] (input) -- node {$R(z)$} (sum);
\draw [arrow] (sum) -- node {$E(z)$} (controller);
\draw [arrow] (controller) -- node {$U(z)$} (plant);
% Posição do rótulo de saída ajustada
\draw [arrow] (plant) -- node (y_out) [pos=0.6] {$Y(z)$} (output);
% --- Realimentação (Feedback) ---
% Ponto de ramificação ajustado para a saída menor
\node [dot, right=1.0cm of plant] (branch) {};
% Caminho de volta mais próximo e com sinal '-' deslocado
\draw [thick] (branch) |- ++(0,-1.3) -| node[pos=0.95, xshift=0.4cm] {\textbf{--}} (sum);
% Detalhe interno do ponto de soma
\draw (sum.north east) -- (sum.south west);
\draw (sum.north west) -- (sum.south east);
\end{tikzpicture}
Malha de Controle Digital (Domínio do Tempo Discreto)
Diagrama de blocos de malha fechada digital com sinais no domínio do tempo discreto (amostras k).
Ver código TikZ
\begin{tikzpicture}[
auto,
node distance=1.5cm,
block/.style={draw, fill=blue!5, rectangle, minimum height=1.2cm, minimum width=2.2cm, align=center, thick},
block_ctrl/.style={draw, fill=green!5, rectangle, minimum height=1.2cm, minimum width=2.2cm, align=center, thick},
sum/.style={draw, circle, minimum size=0.5cm, thick},
arrow/.style={-Stealth, thick},
dot/.style={fill, circle, minimum size=3pt, inner sep=0pt},
every node/.style={font=\small}
]
% --- Nós ---
\node (input) {};
\node [sum, right=1.2cm of input] (sum) {};
\node [block_ctrl, right=of sum] (controller) {Controlador};
% Conversor D/A
\node [block, right=1.5cm of controller, minimum width=1.5cm] (da) {D/A};
% Planta
\node [block, right=1.5cm of da] (plant) {Planta};
\node [right=1.2cm of plant] (output) {};
% --- Caminho Direto ---
\draw [arrow] (input) -- node {$r(nT_s)$} (sum);
\draw (sum.north east) -- (sum.south west);
\draw (sum.north west) -- (sum.south east);
\draw [arrow] (sum) -- node {$e(nT_s)$} (controller);
\draw [arrow] (controller) -- node {$u(nT_s)$} (da);
\draw [arrow] (da) -- node {$\bar{u}(t)$} (plant);
\draw [arrow] (plant) -- node [pos=0.6] (c_node) {$y(t)$} (output);
% --- Realimentação com A/D Alinhado ---
\node [dot] at ($(plant.east)!0.5!(output)$) (branch) {};
% Posicionando o A/D exatamente abaixo do D/A
\node [block, minimum width=1.5cm] at (da.center |- 0,-2.5) (ad) {A/D};
% Caminho da realimentação
\draw [thick] (branch) |- (ad);
\draw [arrow] (ad) -| (sum.south)
node [pos=0.4, above] {$y(nT_s)$}
node [pos=0.9, left] {\textbf{--}};
% --- Container do Computador Digital ---
% Ajustado para englobar a referência interna e o caminho de volta
\draw [dashed, thick] ($(sum.north west)+(-1.4,0.8)$) rectangle ($(controller.south east)+(2.7,-2.8)$);
% Rótulo do Computador
\node [anchor=south west] at ($(sum.north west)+(-0.8,0.8)$) {\textbf{Computador Digital}};
\end{tikzpicture}
Sinais Contínuo, Amostrado e Digital
Três gráficos lado a lado comparando o mesmo sinal em suas representações contínua y(t), amostrada y(nTs) e digital/quantizada y[k].
Ver código TikZ
\begin{tikzpicture}
% Configurações compartilhadas
\pgfplotsset{
my_axis_style/.style={
width=5.5cm, height=4.5cm,
axis lines=middle,
xmin=0, xmax=8.5,
ymin=-0.8, ymax=1.2,
% Remove números e marcas dos eixos
xtick=\empty,
ytick={-0.75,-0.5,-0.25,0.25,0.5,0.75,1.0},
yticklabels=\empty,
extra y ticks={0},
extra y tick labels=\empty,
domain=0:8,
samples=100,
thick,
% Rótulo do eixo Y à esquerda
every axis y label/.style={at={(ticklabel* cs:0.95)}, anchor=east, xshift=-2pt},
every axis x label/.style={at={(ticklabel* cs:0.95)}, anchor=north}
}
}
% 1. Sinal Contínuo y(t)
\begin{axis}[
my_axis_style,
title={\textbf{Contínuo: $y(t)$}},
name=cont,
ylabel={$y(t)$},
xlabel={$t$},
ytick=\empty % Sem grid no contínuo
]
\addplot[blue, smooth] {exp(-0.3*x)*sin(deg(2*x))};
\end{axis}
% 2. Sinal Amostrado y(nTs)
\begin{axis}[
my_axis_style,
title={\textbf{Amostrado: $y(nT_s)$}},
name=amost,
at={(cont.right of south east)},
xshift=1.5cm,
anchor=south west,
ylabel={$y(nT_s)$},
xlabel={$nT_s$},
% Correção do Grid
ymajorgrids=true,
grid style={dashed, gray!30}
]
\addplot[gray, dashed, opacity=0.2] {exp(-0.3*x)*sin(deg(2*x))};
\addplot[blue, ycomb, samples=16, mark=*, mark size=1.5pt] {exp(-0.3*x)*sin(deg(2*x))};
\end{axis}
% 3. Sinal Digital yq[k]
\begin{axis}[
my_axis_style,
title={\textbf{Digital: $y[k]$}},
name=dig,
at={(amost.right of south east)},
xshift=1.5cm,
anchor=south west,
ylabel={$y[k]$},
xlabel={$k$},
% Correção do Grid
ymajorgrids=true,
grid style={dashed, gray!30}
]
\addplot[gray, dashed, opacity=0.2] {exp(-0.3*x)*sin(deg(2*x))};
\addplot[red, const plot, samples=16, mark=square*, mark size=1.5pt] {round(exp(-0.3*x)*sin(deg(2*x))*4)/4};
\end{axis}
\end{tikzpicture}