Doctorado en Ingeniería · 2025
Aportación al diagnóstico no intrusivo de la presión de combustión a partir de la caracterización de la corriente de ionización aplicado a motores de combustión interna de encendido de chispa
Este trabajo aborda la implementación de un sistema no intrusivo de estimación de características de la presión en cámara de combustión, basado en un esquema de detección de corriente de ionización tipo Low-side, aplicado a un motor monocilíndrico instrumentado de encendido por chispa. La sección 2 del trabajo, relativa a la revisión de literatura, comprende tópicos de diagnóstico de motores de combustión, sistemas de encendido y su modelado eléctrico, conceptos básicos de formación del núcleo de llama, química de la combustión, así como los principales modelos de generación de iones, esquemas eléctricos de detección de corriente de ionización, contornos principales de señales de corriente de iones y sus capacidades de diagnóstico asociadas.
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Contenido
- Abstractp. 14
- Contentsp. 8
- List of Figuresp. 11
- List of Tablesp. 16
- Glossaryp. 17
- List of symbols and acronymsp. 18
- Introductionp. 20
- Background and motivationp. 20
- Objectives and methodologyp. 25
- Thesis outlinep. 27
- Literature reviewp. 28
- Introductionp. 20
- Chapter overviewp. 31
- On methods of fault detection and diagnosisp. 31
- Engine ignition systems using sparkp. 34
- Ion current detectionp. 55
- Main schematic circuits for ion current detection and microammetersp. 56
- The independent probe circuitp. 57
- The high-side circuitp. 63
- The low-side circuitp. 69
- Comments about the polarity of the power supply voltage Up. 76
- Comments about using AC for power supply voltage Up. 77
- featuresp. 78
- Conclusions from literature reviewp. 93
- measurementp. 25
- Ignition system measurement setupp. 99
- The ignition coilp. 101
- The resistive high-tension probep. 104
- The inductive voltage probep. 112
- The power source Up. 114
- The microammeter and limiter for ion current measurementp. 118
- The isolation amplifiersp. 123
- Engine Crank and distributionp. 128
- Crank angle sensingp. 128
- Torque sensingp. 130
- Valve displacement sensingp. 136
- Acquisition systemp. 118
- Conclusions from the implementationsp. 145
- Test procedure and preliminary findingsp. 148
- Preliminary considerations for the testsp. 149
- Limiting the acquisition campaignsp. 154
- Table 15. (continued)p. 158
- Description of the softwarep. 160
- Conditioning and referencing of the pressure signal datap. 163
- Preprocessing of the ion current signalp. 165
- Preliminary findings on motoring testsp. 166
- Motoring tests without sparkp. 168
- Motoring tests with ignition system onp. 170
- Preliminary findings on combustion testsp. 180
- Findings with prechamberp. 180
- Findings without prechamberp. 186
- Conclusionsp. 191
- Analysis and correlations between ion current and pressurep. 193
- of combustion chamber pressurep. 194
- relationship with pressurep. 205
- pressurep. 20
- Cyclic variation: pressure peak magnitudep. 208
- Cyclic variation: determination of pressure peak positionp. 211
- pressure peak and its crank angular positionp. 216
- Ignition delay estimationp. 230
- Mass fraction burned and heat release rate estimationsp. 231
- Conclusions of the chapterp. 234
- Final conclusions and future workp. 235
- Introductionp. 20
- Main conclusionsp. 235
- Future workp. 240
- Contributionsp. 242
- Appendix 1p. 244
- Appendix 2p. 245
- Appendix 3p. 246
- Bibliographyp. 248
- Figure 1. Schematic of the methodologyp. 26
- reciprocating combustion enginesp. 29
- Figure 3. Overall scheme of fault detection and diagnosis, based on Isermann. [16]p. 32
- based on Pashley et al. [37]p. 35
- Figure 5. Classic inductive ignition systems, based on Thurman. [39]p. 36
- Figure 6. Schematic diagram of contact-breaker ignition system, from [40]p. 37
- complete, b) simplified, from [40]p. 38
- complete, b) simplified, from [40]p. 38
- wasted spark, based on Sforza et al. [50]and Pischinger et al. [51]p. 43
- multicylinder integrated with ECU, based on Shimasaki et al. [54]p. 44
- Thurman [39]p. 45
- Maly [66], Song and Sunwoo [67], Arcoumanis and Kamimoto [68], Shen et al. [70]p. 49
- T1, transition; AR, arc; T2, transition; and GL, glowp. 51
- Shimasaki et al. [54]p. 53
- microammeterp. 56
- c) with voltage divider (after Gazis et al. [21])p. 57
- and b) with feedback ammeter and isolation amplifier (after Hu et al. [96])p. 61
- Figure 18. High-side circuit for ion current detection. Based on Eriksson. [25]p. 63
- Based on Eriksson. [25], Wang et al. [42] and [40]p. 64
- Figure 20. High-side circuit for ion current detection. Based on Anderson [92]p. 65
- Figure 22. High-side circuit for ion current detection. Based on Laganá et al. [113]p. 67
- Figure 23. High-side circuit for ion current detection. Based on Hunicz et al. [74]p. 68
- and Wang et al. [42]p. 69
- detection. Based on [40]p. 70
- Figure 26. Low-side circuit for ion current detection. Based on Förster et al. [84]p. 73
- Naoumov et al., and (3) Measured ion current. Based on Naoumov et al. [13]p. 83
- and Fiedkiewicz [131]p. 84
- (2.3) Chemoionization; (2.4) Thermoionization. Based on Gürbüz [18]p. 85
- Figure 30. Schematic of the chapterp. 96
- Figure 31. Photo of engine setupp. 96
- Figure 32. Schematic of the engine setupp. 97
- Figure 33. Ignition and ion current measurement systemp. 99
- Figure 35. Transformation ratio as function of the frequency for the ignition coilp. 103
- Figure 36. Schematic diagram of the resistive high-tension probep. 105
- Figure 38. Setup for static calibration of resistive probe (preliminary)p. 107
- Figure 39. Setup for HVDC calibration of resistive probe, a) schematic, b)photop. 108
- and b) photo of the mockupp. 110
- Figure 41. Normalized frequency response of the resistive high voltage probep. 112
- probep. 113
- Figure 43. Frequency response of the resistive high voltage probep. 114
- Figure 45. Schematic diagram of the power supply for ion current measurementp. 117
- Figure 46. Schematic of the shunt resistor and zener limiter implementedp. 119
- Figure 47. Schematic of the test circuit for frequency response of the zener limiterp. 120
- Figure 48. Schematic diagram of the microammeter, limiter and amplifierp. 121
- right:microammeter, power source and VARIACp. 122
- voltage measurementp. 124
- Figure 51. Transient response of the isolation ampliferp. 126
- Figure 52. Frequency response at 10kHzp. 126
- Figure 53. Frequency response at 100kHzp. 127
- Figure 54. Frequency response at 230kHzp. 127
- Figure 55. Schematic diagram of the signal conditioner for the encoderp. 129
- Figure 56. (A+Z) signal indicating 0,1° motion and TDC positionp. 129
- Figure 57. Dynamometer for load torquep. 131
- b) engine in motionp. 131
- Figure 59. Schematic diagram of the loadcell signal conditioning circuitp. 133
- Figure 60.Calibration of loadcell using INST P3p. 134
- Figure 61. Test points for Usig,, Uexc, Uamp y Uabsp. 134
- Figure 62. Calibration of Usig : a)compression, b)tractionp. 135
- Figure 63. Calibration of UAmp : a)compression, b)tractionp. 135
- Figure 64. Calibration of a)AD620 amplifier gain, b) absolute value circuit gainp. 136
- Figure 65. Simplified schematic diagram of the valve opening sensing systemp. 137
- Figure 66. Detailed schematic diagram of the valve opening sensing systemp. 138
- Figure 67. Photos of the transformers installed on the valve cover and circuit boardp. 139
- Figure 68. Tests of frequency for transformer of intake valvep. 140
- Figure 69. Photo of the setup to measure the displacement of the nucleusp. 140
- Figure 70. Characterization of the intake valve stroke measurementp. 141
- Figure 71. Characterization of the exhaust valve stroke measurementp. 141
- (red)p. 142
- Figure 73. Setup for delay between channels, a) complete. b) detail of connectionsp. 143
- Figure 74. Schematic diagram of the multiple acqusition systemp. 144
- Figure 75. Superimposed channels 1 to 8, at f=1kHz. Horizontal axis in “samples”p. 144
- detail of rise. Horizontal axis is in “samples”p. 145
- Figure 77. Schematic view of the chapterp. 148
- Figure 78. Test campaign schematicp. 155
- Figure 79. Matlab® user interfacep. 160
- Figure 80. Sample of gathered signalsp. 161
- Figure 81. Sample of a scaled primary currentp. 161
- Figure 82. Scheme of the conversion of a sampled signal to cyclic signal arraysp. 162
- cleaned. Original pressure signal obtained in motored condition at 500min-1p. 164
- reconstructed (filtered) signal from inverse FFT in cyanp. 164
- Figure 85. Scheme of the code for pressure signal correctionp. 165
- drive and b) Additional instrumentationp. 166
- Figure 88. Setup for motoring with DC compound motorp. 167
- Figure 89. Schematic of the power supply for the DC compound motorp. 168
- sparkp. 156
- Figure 91. Sample of cyclic ion current during motoring without sparkp. 169
- crank angle during motoring without sparkp. 170
- Figure 94. Details of B1 (compression) and B2 (wasted spark)p. 172
- measured with both probes, without prechamberp. 175
- Figure 97. Comparisons between ion factors a) 104 and b) 105 for the microammeterp. 176
- Figure 98. Comparisons between combinations of Rion and G for the microammeterp. 178
- measured with both probes. U = -100Vp. 179
- Figure 100. Modification to the ignition modulep. 180
- Figure 101. Cyclic plots of a) ion current, and b) pressurep. 181
- pressure, ion current and secondary voltage (both probes)p. 182
- and secondary voltage (both probes). U = -300Vp. 183
- voltage (both probes). U = 100Vp. 184
- measured with both probes, with prechamberp. 185
- pressure deviation, c) ion current, d) secondary voltage (clamp)p. 187
- current, valve displacements and secondary voltage (both probes)p. 188
- and ion currentsp. 189
- includes the inductive effects of both coilsp. 194
- couplingp. 199
- Figure 112. Free run frequencies observed on ion current signal as function of timep. 200
- preceding the ionization of the air-fuel mixturep. 201
- values of Rionp. 203
- = 1, except for Rion = 100 p. 204
- c) windowed ionization current, d) ionization current integralp. 207
- under the curve, and b) regression model of the variablesp. 208
- and regression model of the variablesp. 209
- ionization peak of ionization current signal and regression model of the variablesp. 209
- of normalized ion signal area and damped natural frequencyp. 210
- Figure 121. Peak pressure position compared with the centroid of ion areap. 211