This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
A Controller for a Spark Ignition Engine with Bi-Fuel Capability
Annotation ability available
Sector:
Language:
English
Abstract
A bi-fuel engine with the ability to run optimally on both compressed natural gas (CNG) and gasoline is being developed. Such bi-fuel automotive engines are necessary to bridge the gap between gasoline and natural gas as an alternative fuel while natural gas fueling stations are not yet common enough to make a dedicated natural gas vehicle practical. As an example of modern progressive engine design, a Saturn 1.9 liter 4-cylinder dual overhead cam (DOHC) engine has been selected as a base powerplant for this development. Many previous natural gas conversions have made compromises in engine control strategies, including mapped open-loop methods, or resorting to translating the signals to or from the original controller. The engine control system described here, however, employs adaptive closed-loop control, optimizing fuel delivery and spark timing for both fuels. Each fuel is metered by solenoid injectors and the fuel injection control maintains a preset air-fuel ratio using a universal exhaust gas oxygen sensor (UEGO). Spark timing is controlled to maintain the location of peak in-cylinder pressure at the optimum value for best torque, which was determined experimentally to be 14° after top dead center for this engine. In-cylinder pressure was measured in the experimental engine using piezoelectric pressure transducers flush-mounted in the cylinder head. Location of peak pressure was determined in real time with the IBM-compatible 486 computer used for control, and was used to modify the spark advance for the next engine event in that cylinder. Reductions in engine-out emissions of hydrocarbons, carbon dioxide, and oxides of nitrogen, as compared with stock operation, were observed when using the controller with gasoline. Further reductions in emissions were achieved with CNG operation, due to the properties of the fuel. An improvement in engine stability was also realized with the controller.
Recommended Content
Authors
Topic
Citation
Atkinson, R., Tennant, C., Traver, M., Atkinson, C. et al., "A Controller for a Spark Ignition Engine with Bi-Fuel Capability," SAE Technical Paper 942004, 1994, https://doi.org/10.4271/942004.Also In
References
- Tennant, C. de Jong, R. Atkinson, R. Traver, M. Atkinson, C. Vincent, C. Clark, N. Lyons, D. “Performance of a High Speed Engine with Dual Fuel Capability” SAE Paper 940517
- Chrysler Canada LTD. “The Development of an Optimized Dual-Fuel Gasoline-Propane Passenger Car, ” Paper Prepared for Energy, Mine and Resources Canada and Province of Ontario
- King, S. R. “ The Impact of Natural Gas Composition on Fuel Metering and Engine Operational Characteristics,” SAE Paper 920593
- Liss, W. E. Thrasher, W. H. “Natural Gas as a Stationary Engine and Vehicular Fuel,” SAE Paper 912364
- Beck, N.J. Johnson, W.P. Peterson, P.W. “Optimized E.F.I, for Natural Gas Fueled Engines,” SAE Paper 911650
- Franklin, M.L. Kittelson, D.B. Leuer, R.H. Pipho, M.J. “A PC-based Fuel and Ignition Control System Used to Map the 3-D Surfaces of Torque and Emissions Versus Air-Fuel Ratio and Ignition Timing,” SAE Paper 940546
- Noble, A.D. Beaumont, A.J. “Control System for a Low Emissions Natural Gas Engine for Urban Vehicles,” SAE Paper 910255
- Varde, K.S. Cherng, J.C. Bailey, C.J. Majewski, W.A. “Emissions and Their Control in Natural Gas Fueled Engines,” SAE Paper 922250
- Kawamura, Y. Shinshi, M. Sato, H. Takahashi, N. Iriyama, M. “MBT Control through Individual Cylinder Pressure Detection” SAE Paper 881779
- Quayle, R.S. Bhot, S. R. “Assessment of a strategy for optimum control of ignition advance angle,” Proceedings of the Institute of Mechanical Engineers 202 D1 1 8
- Heywood, J. B. “Internal Combustion Engine Fundamentals” McGraw-Hill New York 1988
- Herden, W. Küsell, M. “A New Combustion Pressure Sensor for Advanced Engine Management” SAE Paper 940379
- Weaver, C. S. “Natural Gas Vehicles - A Review of the State of the Art,” SAE Paper 892133
- Yamada, T. Hayakawa, N. Kami, Y. Kawai, T. “Universal Air-Fuel Ratio Heated Exhaust Gas Oxygen Sensor and Further Applications” SAE Paper 920234