The torque produced by each combustion in an engine is one of the most important indices tied to internal combustion engine performance. In this paper, an approach is investigated to estimate engine torque. Instead of employing expensive and delicate combustion pressure sensors to directly measure indicated pressure in each cylinder, unknown input observers are exploited to estimate cylinder indicated torque using one or more low-cost measurements of crankshaft angular position. Necessary and sufficient conditions for the existence of such torque estimators for multi-cylinder engines are presented in the paper; these include the number of angular position sensors required and their suggested placement. Model reduction issues and the number of measurements required to obtain an acceptable estimate are also considered. The approach is applied to a six-cylinder industrial diesel engine.

Issue Section:
Technical Papers
Topics:
Design, Internal combustion engines, Torque, Cylinders, Engines, Combustion, Diesel engines, Pressure, Pressure sensors, Sensors
1.
Connolly
 
F.
, and
Rizzoni
 
G.
,
1994
, “
Real Time Estimation of Engine Torque for Detection of Engine Misfire
,”
ASME JOURNAL OF DYNAMIC SYSTEMS, MEASUREMENT, AND CONTROL
, Vol.
116
, pp.
675
–
680
.
2.
Drakunov, S., Rizzoni, G., and Wang, Y. Y., 1995, “On-line Estimation of Indicated Torque in IC Engines using Nonlinear Observers,” 1995 SAE International Congress and Exposition, Paper No. SP-1086K, Detroit, MI.
3.
Ferenbach, H., 1990, “Model Based Combustion Pressure Computation through Crankshaft Angular Acceleration Analysis,” Paper No. 900021, Proceedings of the XXII Int’l Symposium on Automotive Technology and Automation, Florence, Italy.
4.
Iida, K., Akishino, K., and Kido, K., 1990, “IMEP Estimation from Instantaneous Crankshaft Torque Variation,” SAE Technical Paper No. 900617.
5.
Lee, D., and Rizzoni, G., “Detection of Partial Misfire in IC Engines using a Measurement of Crankshaft Angular Velocity,” SAE Technical Paper 951070, 1995 SAE Transactions, Journal of Engines.
6.
Kao, M., and Moskwa, J., 1993, “Nonlinear Turbo-charged Diesel Engine Control and State Observation,” ASME Winter Annual Meeting, New Orleans, LA, pp. 187–198.
7.
Miu
 
D. K.
, and
Yang
 
B.
,
1994
, “
On the Transfer Function Zeros of the General Colocated Control Systems with Mechanical Flexibility
,”
ASME JOURNAL OF DYNAMIC SYSTEMS, MEASUREMENT, AND CONTROL
, Vol.
116
, pp.
151
–
153
.
8.
Mu¨ller
 
P. C.
, and
Hou
 
M.
,
1992
, “
Design of Observers for Linear Systems for Unknown Inputs
,”
IEEE Transactions on Automatic Control
, Vol.
AC-37
, No.
6
, pp.
871
–
874
.
9.
Rizzoni, G., 1989, “Estimate of Indicated Torque from Crankshaft Speed Fluctuations: A Model for the Dynamics of IC Engine,” IEEE Transactions on Vehicular Technology, Vol. VT-38, No. 3, pp.
10.
Rizzoni, G., and Ribbens, W. B., 1992, “An Integrated Circuit Engine Analyzer for IC Engine On-Board Diagnostics,” Proc. 1992 FISITA Conference, Vol. 2, The Vehicle and the Environment, pp. 121–126, London, U.K., June 8–11.
11.
Drakunov, S., Rizzoni, G., and Wang, Y., 1995, “Estimation of Engine Torque Using Nonlinear Observers in the Crank Angle Domain,” Proc. 5th ASME Symposium on Advanced Automotive Technologies, 1995 ASME IMECE, San Francisco, CA, Nov.
12.
Rizzoni
 
G.
, and
Zhang
 
Y. X.
,
1994
, “
Identification of A Nonlinear Internal Combustion Engine Model for On-line Indicated Torque Estimation
,”
Mechanical Systems and Signal Processing
, Vol.
8
, No.
3
, pp.
274
–
287
.
13.
Shiao
 
Y.
, and
Moskwa
 
J.
,
1995
, “
Cylinder Pressure and Combustion Heat Release Estimation for SI Engine Diagnostics Using Nonlinear Sliding Mode Observers
,”
IEEE Transactions on Control System Technology
, Vol.
3
, pp.
70
–
77
.
14.
Srinivasan, K., Rizzoni, G., Trigui, V., and Luh, G. C., 1992, “On-line Estimation of Net Engine Torque from Crankshaft Angular Velocity Measurement Using Repetitive Estimators,” Proceedings of the American Control Conference, pp. 516–520.
15.
Symos
 
V. L.
,
1993
, “
Computational Observer Design Techniques for Linear System with Unknown Inputs Using the Concept of Transmission zeros
,”
IEEE Transactions on Automatic Control
, Vol.
AC-38
, pp.
790
–
794
.
16.
Wang
 
Y. Y.
,
Krishnaswami
 
V.
, and
Rizzoni
 
G.
,
1997
, “
Event-Based Estimation of Indicated Torque for IC Engines Using Sliding Mode Observers
,”
Control Engineering Practice
, Vol.
5
, No.
8
, pp.
1123
–
1129
.
This content is only available via PDF.
Copyright © 1999
 by The American Society of Mechanical Engineers
You do not currently have access to this content.