From ce7de75626bcd9d6cf0477144b523de1848aadf7 Mon Sep 17 00:00:00 2001 From: Your Name Date: Thu, 29 Mar 2012 17:07:42 +0100 Subject: [PATCH] ... --- submission_thesis/CH5_Examples/copy.tex | 40 ++++++++++--------------- 1 file changed, 16 insertions(+), 24 deletions(-) diff --git a/submission_thesis/CH5_Examples/copy.tex b/submission_thesis/CH5_Examples/copy.tex index 0b09147..5ce122b 100644 --- a/submission_thesis/CH5_Examples/copy.tex +++ b/submission_thesis/CH5_Examples/copy.tex @@ -1932,6 +1932,8 @@ take the mean square error of these accuracy figures. \paragraph{Single Fault FMEA Analysis \\ of PT100 Four wire circuit} + +\ifthenelse {\boolean{pld}} \paragraph{Single Fault Modes as PLD} The component~failure~modes in table \ref{ptfmea} can be represented as contours @@ -1939,11 +1941,7 @@ on a PLD diagram. Each test case, is defined by the contours that enclose it. The test cases here deal with single faults only and are thus enclosed by one contour each. - - \fmodegloss - - \begin{figure}[h] \centering \includegraphics[width=400pt,bb=0 0 518 365,keepaspectratio=true]{./CH5_Examples/pt100_tc.png} @@ -1951,6 +1949,7 @@ and are thus enclosed by one contour each. \caption{PT100 Component Failure Modes} \label{fig:pt100_tc} \end{figure} +} % \ifthenelse {\boolean{pld}} %ating input Fault This circuit supplies two results, the {\em sense+} and {\em sense-} voltage readings. @@ -1959,21 +1958,7 @@ valid temperature range for this example ({0\oc} .. {300\oc}) we can calculate valid voltage reading ranges by using the standard voltage divider equation \ref{eqn:vd} for the circuit shown in figure \ref{fig:vd}. -% -%\begin{figure}[h] -% \centering -% \includegraphics[width=100pt,bb=0 0 183 170,keepaspectratio=true]{./pt100/voltage_divider.png} -% % voltage_divider.png: 183x170 pixel, 72dpi, 6.46x6.00 cm, bb=0 0 183 170 -% \caption{Voltage Divider} -% \label{fig:vd} -%\end{figure} -%%The looking at figure \ref{fig:vd} the standard voltage divider formula (equation \ref{eqn:vd}) is used. -% -%\begin{equation} -%\label{eqn:vd} -% V_{out} = V_{in}.\frac{Z2}{Z2+Z1} -%\end{equation} -% + \paragraph{Proof of Out of Range \\ Values for Failures} @@ -2232,7 +2217,7 @@ The FIT for the circuit as a whole is the sum of MTTF values for all the test cases. The PT100 circuit here has a FIT of 342.6. This is a MTTF of about 360 years per circuit. -A Probablistic tree can now be drawn, with a FIT value for the PT100 +A probabilistic tree can now be drawn, with a FIT value for the PT100 circuit and FIT values for all the component fault modes that it was calculated from. We can see from this that that the most likely fault is the thermistor going OPEN. This circuit is around 10 times more likely to fail in this way than in any other. @@ -2458,6 +2443,8 @@ This shorts the sense+ and sense- to Vcc. Both values will be out of range. \clearpage + + \subsection{Double Faults Represented on a PLD Diagram} We can show the test cases on a diagram with the double faults residing on regions @@ -2487,11 +2474,13 @@ In all the test case results we have at least one out of range value, except for $TC\_7$ which has two unknown values/floating readings. We can collect all the faults, except $TC\_7$, into the symptom $OUT\_OF\_RANGE$. -As a symptom $TC\_7$ could be described as $FLOATING$. We can thus draw a PLD diagram representing the +As a symptom $TC\_7$ could be described as $FLOATING$. + +\ifthenelse {\boolean{pld}} +We can thus draw a PLD diagram representing the failure modes of this functional~group, the pt100 circuit from the perspective of double simultaneous failures, in figure \ref{fig:pt100_doublef}. - \begin{figure}[h] \centering \includegraphics[width=450pt,bb=0 0 730 641,keepaspectratio=true]{./CH5_Examples/plddoublesymptom.png} @@ -2499,14 +2488,15 @@ in figure \ref{fig:pt100_doublef}. \caption{PT100 Double Simultaneous Faults} \label{fig:plddoublesymptom} \end{figure} - +} %% \ifthenelse {\boolean{pld}} \clearpage \subsection{Derived Component : The PT100 Circuit} The PT100 circuit again, can now be treated as a component in its own right, and has two failure modes, {\textbf{OUT\_OF\_RANGE}} and {\textbf{FLOATING}}. -It can now be represented as a PLD see figure \ref{fig:pt100_doublef}. +\ifthenelse {\boolean{pld}} +It can now be represented as a PLD see figure \ref{fig:pt100_doublef}. \begin{figure}[h] \centering \includegraphics[width=100pt,bb=0 0 167 194,keepaspectratio=true]{./CH5_Examples/pt100_doublef.png} @@ -2514,6 +2504,8 @@ It can now be represented as a PLD see figure \ref{fig:pt100_doublef}. \caption{PT100 Circuit Failure Modes : From Double Faults Analysis} \label{fig:pt100_doublef} \end{figure} +} % \ifthenelse {\boolean{pld}} + \subsection{Statistics}