An Object-Oriented Modular Simulation Model for Integrated Gasoline Engine and Automatic Transmission Control

In this paper a computer simulation model for control system design of gasoline engines with an automatic transmission is presented. A modular programming approach has been pursued, and MATLAB/SIMULINK has been utilized as a programming environment. Engine/transmission systems are analyzed in the objectoriented fashion. Thus, easy construction of various computer models by assembling various objects is possible. An object in this paper represents a physical part, an equation, or an algorithm. The top level in the powertrain model consists of three classes: an engine, a transmission, and a driveline. Each class is designed to perform by itself. The construction procedure of a typical powertrain model together with supplementary explanation is demonstrated. It is expected that the whole program and individual class constructed in this paper are useful for the automotive engineers who design a new engine/transmission system and/or modify an existing system. INTRODUCTION In the automotive industry, the enhancement of the ride quality, fuel efficiency, and exhaust emission of a newly introduced vehicle has been continuously emphasized. This endeavor can be substantially achieved by improving the performance of the powertrain, which is a primary element of the noise, vibration, harshness, and fuel efficiency of a vehicle. Fig. 1 shows the schematic diagram of a typical powertrain system. An integrated control of the powertrain system refers to a combined control of the hitherto separated engine and transmission controls as shown in Fig. 2. The subject of powertrain control will play a central role among the many issues related to the control of the vehicle[1,2]. One challenging engineering problem is to build a software model with a computer which imitates or reproduces the behavior of a real plant. If this goal is achieved, then the cost and time needed to develop a better performing machine can be greatly reduced. It would be very effective if the dynamic performance of a newly configured powertrain system could be evaluated from the early stages of its design with a computer model before making its prototype.