This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Closed-Loop Control of Spark Advance and Air-Fuel Ratio in SI Engines Using Cylinder Pressure
Technical Paper
2000-01-0933
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Event:
SAE 2000 World Congress
Language:
English
Abstract
The introduction of inexpensive cylinder pressure sensors provides new opportunities for precise engine control. This paper presents a control strategy of spark advance and air-fuel ratio based upon cylinder pressure for spark ignition engines. In order to extend the cylinder pressure based engine control to a wide range of engine speeds, the appropriate choice of control parameters is important as well as essential.
For this control scheme, peak pressure and its location for each cylinder during every engine cycle are the major parameters for controlling the air-fuel ratio and spark timing. However, the conventional method requires the measurement of cylinder pressure at every crank angle degree to determine the peak pressure and its location. In this study, the peak pressure and its location were estimated, using a multi-layer feedforward neural network, which needs only five cylinder pressure samples at -40°, -20°, 0°, 20°, and 40° after TDC.
The neural network plays an important role in mitigating the A/D conversion load of an electronic controller by increasing the sampling interval from 1°crank angle (CA) to 20°CA. The estimated location of the peak pressure can be regarded as a good index for combustion phasing, and can also be used as an MBT control parameter. The peak pressure reflects the air-fuel ratio from rich mixture to lean mixture near the lean misfire limit, and can be used as an air-fuel ratio control parameter as well.
The feasibility of this methodology was closely examined through steady and transient engine operations to control spark advance and air-fuel ratio. Moreover, a commercial two-liter four-cylinder engine was employed in this experiment. The experimental results revealed a favorable agreement between the real MBT and target air-fuel ratio.
Recommended Content
Authors
Topic
Citation
Yoon, P., Park, S., Sunwoo, M., Ohm, I. et al., "Closed-Loop Control of Spark Advance and Air-Fuel Ratio in SI Engines Using Cylinder Pressure," SAE Technical Paper 2000-01-0933, 2000, https://doi.org/10.4271/2000-01-0933.Also In
References
- Eriksson Lars et al. “Closed Loop Ignition Control by Ionization Current Interpretation,” SAE paper 970854
- Upadhyay Devesh Rizzoni Giorgio “AFR Control on a Single Cylinder Engine using the Ionization Current,” SAE paper 980203
- Hellring Magnus et al. “Robust AFR Estimation using the Ion Current and Neural Network,” SAE paper 1999-01-1161
- Powell J. D. “Engine Control using Cylinder Pressure: Past, Present, and Future,” ASME, Journal of Dynamic Systems, Measurements, and Control 115 1993
- Fujii Isao et al. “MBT Feedback Control System in Spark Ignition Engines,” Transactions of Society of Automotive Engineers of Japan 28 3 July 1997
- Haykin Simon “Neural Networks - A Comprehensive Foundation,” Macmillan College Publishing Company