# Research on Fault Diagnosis of Marine Diesel Engines Based on CNN-TCN-ATTENTION
## 3 Experiment
### Experimental Data
#### 3.1.2 Data Acquisition and Preprocessing  
In this paper, the fault parameter for the diagnostic model is chosen from the thermodynamic parameters produced during diesel engine operation. To provide a comprehensive display of how various faults affect the engine's performance, 22 thermodynamic parameters are chosen as fault data. These include the following: speed (N), maximum pressure (Pz), effective torque (T), intake air flow (F), effective power (Pe), indicated power (Pi), Indicated Mean Effective Pressure (IMEP), Brake Mean Effective Pressure (BMEP), Indicated Specific Fuel Consumption (ISFC), Brake Specific Fuel Consumption (BSFC), turbocharger outlet pressure (Pmp1) and temperature (Tmp1), intercooler outlet pressure (Pmp2) and temperature (Tmp2), cylinder intake pressure (Pmp3) and temperature (Tmp3), cylinder exhaust pressure (Pmp4) and temperature (Tmp4), turbine inlet pressure (Pmp5) and temperature (Tmp5), and turbine outlet pressure (Pmp6) and temperature (Tmp6). In the GT-Power software (Version 2020), the diesel engine model is set with the four faults listed in Table 2. Fault values are taken every 0.87 s (one cycle time), and for each fault, 360 sets of data are collected with a duration of 313.2 s. Similarly, data are collected for the normal state with the corresponding number of cycles. This results in a total of 1800 sets of 22-dimensional data, with 1440 sets of fault data and 360 sets of normal data. A part of the operation data is shown in Table 5. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Fault Type**} & \multicolumn{2}{c}{**Fault Feature**} & \multirow{2}{*}{**Normal Value**} & \multicolumn{2}{c}{**Fault Severity Level**} & \\  & **Parameter** & & & & & \\ \hline F3 & Gas capacity per cylinder/g & 71.3 & 67.74 & 64.17 & 60.61 & 57.04 \\ F4 & Turbine failure/\% & 100 & 95 & 90 & 85 & 80 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: _Cont._ \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Parameter**} & \multicolumn{4}{c}{**Parameter Values for 5 Running States**} \\ \cline{2-5}  & **F0** & **F1** & **F2** & **F3** & **F4** \\ \hline N (r/min) & 69.27 & 68.25 & 68.01 & 68.26 & 68.26 \\ Pz (bar) & 172.3 & 151.98 & 153.42 & 155.92 & 151.89 \\ T (N-m) & 1,850,111.60 & 1,791,066.60 & 1,778,327.60 & 1,792,177.60 & 1,791,566.60 \\ F (g/s) & 5028.95 & 3822.88 & 3960.63 & 5042.83 & 3816.25 \\ Pi (Kw) & 13,696.50 & 13,058.63 & 12,921.95 & 13,067.69 & 13,064.00 \\ Pe (Kw) & 13,435.14 & 12,801.39 & 12,665.61 & 12,810.43 & 12,806.73 \\ IMEP (bar) & 15.72 & 15.23 & 15.12 & 15.24 & 15.23 \\ BMEP (bar) & 15.42 & 14.93 & 14.82 & 14.94 & 14.93 \\ ISFC & 140.32 & 144.85 & 145.87 & 140.30 & 144.81 \\ (g/Kwh) & 143.05 & 147.76 & 148.82 & 143.11 & 147.72 \\ Pmp1 (bar) & 4.03 & 3.27 & 3.43 & 3.93 & 3.27 \\ Tmp1 (K) & 476 & 491.54 & 500 & 483.41 & 455.68 \\ Pmp2 (bar) & 4.04 & 3.27 & 3.43 & 3.93 & 3.26 \\ Tmp2 (K) & 313.65 & 315.39 & 352.34 & 313.56 & 313.82 \\ Pmp3 (bar) & 3.58 & 3.03 & 3.03 & 3.51 & 3.03 \\ Tmp3 (K) & 312.87 & 314.53 & 349.28 & 312.68 & 313.05 \\ Pmp4 (bar) & 3.43 & 2.73 & 2.83 & 3.33 & 2.74 \\ Tmp4 (K) & 624.76 & 701.47 & 718.37 & 569.44 & 700.86 \\ Pmp5 (bar) & 3.9 & 3.16 & 3.29 & 3.76 & 3.15 \\ Tmp5 (K) & 660 & 743.35 & 757.01 & 643.49 & 742.74 \\ Pmp6 (bar) & 1.01 & 1.01 & 1.01 & 1.01 & 1.01 \\ Tmp6 (K) & 486 & 580.90 & 586.59 & 483.02 & 612.89 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Thermodynamic parameter data for diesel engine under different states. To confirm that the simulated defects are effective, a qualitative analysis is conducted by comparing the deviation rate of fault data at different fault severities against the thermodynamic parameters under normal conditions. The qualitative analysis is shown in Figure 12. The fault simulation results align with the expert experience analysis, verifying the accuracy and reasonableness of the fault simulation data. The formula for the qualitative analysis is presented in Equation (10).