Development of a Technique for Extraction of Transient Control Strategies from Automotive Electronic Control Units, 03-9247

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Principal Investigators
Arun T. Vemuri
Jayant Sarlashkar
Joseph Grogan

Inclusive Dates: 04/01/01 - 04/01/02

Background - Automotive system benchmarking is a common practice used by automotive companies and government agencies. The benchmarking process of an automotive engine involves understanding the mechanical aspects of the engine as well as the electronic controller. The automotive control system consists of a number of subcontrol systems. Each subcontrol system typically consists of a steady-state component and a transient component. The steady-state component, as the name implies, is responsible for the control of the relevant subsystem during steady-state operation while the transient component is responsible for controlling the subsystem behavior during transient events such as throttle tip-in. A number of techniques have been developed to characterize the input-output characteristics of steady-state component. The identification of the transient component of the control system, however, is considerably more difficult and has not received attention in the literature. This project investigates the characterization process of the transient-component of a production automotive engine control system.

Approach - This project proposes to develop a general benchmarking methodology controller by investigating the characterization process of a state-of-the art diesel engine used in the latest passenger cars. This engine is currently in use on an Engine, Emissions and Vehicle Research Division project. Further, a specific subsystem - the engine’s fuel control subsystem - will be used to develop the control system characterization methodology. The control strategy benchmarking process will involve proposing a mathematical structure in the form of a difference equation. Standard system identification methods will then be used to estimate the calibrations in the difference equation.

Accomplishments - Steady-state data have been collected and are being analyzed. The load-speed range under which the steady-state data have been collected is shown below. The data are being analyzed to extract steady-state behavior of various actuators. This behavior will then be used to benchmark the transient algorithms.

Speed-load points at which steady-state data have been collected.

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