0
Research Papers: Internal Combustion Engines

Analysis of the Interactions Between Indicated and Reciprocating Torques for the Development of a Torsional Behavior Model of the Powertrain

[+] Author and Article Information
Fabrizio Ponti, Luca Solieri

DIEM, University of Bologna, Via, Fontanelle 40, Forlí 47100, Italy

J. Eng. Gas Turbines Power 130(6), 062803 (Aug 21, 2008) (9 pages) doi:10.1115/1.2939010 History: Received September 16, 2007; Revised April 08, 2008; Published August 21, 2008

Torque-based engine control systems usually employ a produced torque estimation feedback in order to verify that the strategy target torque has been met. Torque estimation can be performed using static maps describing the engine behavior or using models describing the existing relationships between signals measured on the engine and the indicated torque produced. Signals containing information on the combustion development, suitable for this purpose, are, among others, the ion-current signal, the vibration signals obtained from accelerometers mounted on the engine block, or the instantaneous engine speed fluctuations. This paper presents the development and the identification process of an engine-driveline torsional behavior model that enables indicated torque estimation from instantaneous engine speed measurement. Particular attention has been devoted to the interactions between indicated and reciprocating torques, and their effects over instantaneous engine speed fluctuations. Indicated and reciprocating torques produce, in fact, opposite excitations on the driveline that show opposite effects on the engine speed wave form: For low engine speed, usually indicated torque prevails, while the opposite applies for higher engine speed. In order to correctly estimate indicated torque from engine speed measurement, it is therefore necessary to correctly evaluate the reciprocating torque contribution. Reciprocating torque is usually described using a wave form as a function of crank angle, while its amplitude depends on the value of the reciprocating masses. As mentioned before, knowledge of the reciprocating masses is fundamental in order to obtain correct estimation of the indicated torque. The identification process that has been set up for the engine-driveline torsional model enables to evaluate the relationship between torques applied to the engine and the corresponding engine speed wave form even without knowing the value of the reciprocating masses. In addition, once this model has been set up, it is possible to estimate with high precision the value of the reciprocating masses. Particular attention has also been devoted to the feasibility of the application of the identified model onboard for torque estimation; for this reason, the model has been developed in a very simple form. The approach proved to be effective both on gasoline and diesel engines, both for engine mounted on a test cell and onboard, with different engine configurations. Examples of application are given for some of the configurations investigated.

Copyright © 2008 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Flowchart of the methodology employed for indicated torque estimation

Grahic Jump Location
Figure 2

Scheme of the inertia-stiffness equivalent representation to describe the system dynamic behavior

Grahic Jump Location
Figure 3

Amplitude and phase of the indicated torque Order 2 component for an L4 multijet diesel engine at different percentages of full load

Grahic Jump Location
Figure 4

Amplitude and phase of the reciprocating torque Order 2 component for an L4 multijet diesel engine at different percentages of full load

Grahic Jump Location
Figure 5

Amplitude and phase of the indicated torque Order 3 component for a V6 gasoline engine at different percentages of full load

Grahic Jump Location
Figure 6

Amplitude and phase of the reciprocating torque Order 3 component for a V6 gasoline engine at different percentages of full load

Grahic Jump Location
Figure 7

Engine speed wave forms for a V6 gasoline engine running at 2100rpm and different loads

Grahic Jump Location
Figure 8

Indicated torque wave forms for a V6 gasoline engine running at 2100rpm and different loads

Grahic Jump Location
Figure 9

Indicated and reciprocating torque difference for a V6 gasoline engine running at 2100rpm and different loads

Grahic Jump Location
Figure 10

Engine speed difference for a V6 gasoline engine running at 2100rpm and different loads

Grahic Jump Location
Figure 11

Indicated torque difference for a V6 gasoline engine running at 2100rpm and different loads

Grahic Jump Location
Figure 12

Amplitude and phase of the identified FRF

Grahic Jump Location
Figure 13

Engine speed wave forms for an L4 diesel engine running at 3500rpm and different loads (third gear)

Grahic Jump Location
Figure 14

Indicated torque wave forms for an L4 diesel engine running at 3500rpm and different loads (third gear)

Grahic Jump Location
Figure 15

Engine speed difference for an L4 diesel engine running at 3500rpm and different loads (third gear)

Grahic Jump Location
Figure 16

Indicated torque difference for an L4 diesel engine running at 3500rpm and different loads (third gear)

Grahic Jump Location
Figure 17

Amplitude and phase of the identified FRF (third gear)

Grahic Jump Location
Figure 18

Engine speed trace during the ramp tests run for FRF identification purposes

Grahic Jump Location
Figure 19

Amplitude and phase of the identified FRF for different gears inserted

Grahic Jump Location
Figure 20

Measured and estimated Order 2 indicated torque frequency component for the L4 diesel engine (third gear)

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In