The improvement of internal combustion engine is largely accomplished though the introduction of innovative actuators that allow optimization and control of the flow, mixing, and combustion processes. The realization of such a novel system depends on the existence of an operational controller that will stabilize the engine and allow experimental testing which, consequently, leads to further development of the actuator and the engine controller. This iterative process requires a starting point which is the development of a control-oriented model. Although not fully validated, the control-oriented model reveals issues associated with uncertainties, nonlinearities, and limitation of different subsystems. Moreover, it aides in defining the controller structure and the necessary parameters for the calibration of the closed loop system. In this paper (Part I) we describe the development process of a control-oriented model for a camless intake process. We first model the multicylinder crankangle-based breathing dynamics and validate it against experimental data of a conventional engine with cam-driven valve profile during unthrottled operation. We then employ the assumption of uniform air pulses during the intake duration and derive a simple input-output representation of the cylinder air charge, pumping losses and associated uncertainties that can be used for designing an electronic valvetrain controller (Part II). [S0022-0434(00)02901-4]

1.
Elrod, A. C., and Nelson, M. T., 1986, “Development of a Variable Valve Timing Engine to Eliminate the Pumping Losses Associated with Throttled Operation,” SAE Paper No. 860537.
2.
Gray, C., 1988, “A Review of Variable Engine Valve Timing,” SAE Paper No. 880386.
3.
Ma, T. H., 1986, 1996, “Recent Advances in Variable Valve Timing,” Alternative and Advanced Automotive Engines, Plenum Press, New York.
4.
Schecter, M. M., and Levin, M. B., 1996, “Camless engine,” SAE Paper No. 960581.
5.
Meacham, G.-B., 1970, “Variable Cam Timing as an Emission Control Tool,” SAE Paper No. 700645.
6.
Moriya, Y., Watanabe, A., Uda, H., Kawamura, H., Yoshioka, M., and Adachi, M. 1996, “A Newly Developed Intelligent Valve Timing System—Continuously Controlled Cam Phasing as Applied to A New 3 Liter Inline 6 Engine,” SAE Paper No. 960579.
7.
Anderson, M., Tsao, T.-C., and Levin, M., 1998, “Adaptive Lift Control for a Camless Electrohydraulic Valvetrain,” SAE Paper No. 981029.
8.
Kim, D., Anderson, M., Tsao, T.-C., and Levin, M. 1997, “A Dynamic Model of a Springless Electrohydraulic Camless Valvetrain System,” SAE Paper No. 970248.
9.
Ahmad, T., and Theobald, M. A., 1989, “A Survey of Variable Valve Actuation Technology,” SAE Paper No. 891674.
10.
Sono, H., and Umiyama, H. 1994, “A Study of Combustion Stability of Non-Throttling Sl Engine with Early Intake Valve Closing Mechanism,” SAE Paper No. 945009.
11.
Ashhab, M. S., Stefanopoulou, A. G., Cook, J. A., and Levin, M., “Camless Engine Control for Robust Unthrottled Operation,” SAE Paper No. 981031.
12.
Urata, Y., Umiyama, H., Shimizu, K., Fujiyoshi, Y., Sono, H., and Fukuo, K., “A Study of Vehicle Equipped with Non-Throttling SI Engine with Early Intake Valve Closing,” SAE Paper No. 930820.
13.
Moraal, P. E., Cook, J. A., and Grizzle, J. W., 1995, “Modeling the Induction Process of an Automobile Engine,” Control Problems in Industry, I. Lasiecka and B. Morton, ed., Birkhauser, Basel, pp. 253–270.
14.
Powell, B. K., and Cook, J. A. 1987, “Nonlinear Low Frequency Phenomenological Engine Modeling and Analysis,” Proc. 1987 Amer. Contr. Conf. 1, pp. 332–340, June.
15.
Heywood, J. B., 1988, Internal Combustion Engine Fundamentals, McGraw-Hill, New York, NY.
16.
Broome, D., 1969, “Induction Ram: Part I, II, III,” Automobile Engineer, Apr., May, June.
17.
Ohata, A., and Ishida, Y., 1982, “Dynamic Inlet Pressure and Volumetric Efficiency of Four Cylinder Engine,” SAE Paper No. 820407.
18.
Novak, J. M., 1977, “Simulation of the Breathing Process and Air-Fuel Ratio Distribution Characteristics of Three-Valve, Stratified Charge Engines,” SAE Paper No. 770881.
19.
Shampine
,
L. F.
, and
Gear
,
C. W.
,
1979
, “
A User’s View of Solving Stiff Differential Equations
,”
SIAM Rev.
,
21
, No.
1
, pp.
1
17
.
20.
Miller, R. H., Davis, G. C., Newman, C. E., and Levin, M. B., 1997, “Unthrottled Camless Valvetrain Strategy for Spark-Ignited Engines,” Proc. ASME ICE 29-1, pp. 81–94.
You do not currently have access to this content.