Engine Control using a Real-Time 1D Engine Model

Zusammenfassung

Emissions legislation, the increasing complexity of vehicle powertrain systems and pressures on cost reduction are governing the growing demands on future Electronic Control Units (ECUs). The currently widely-used ECU mean value modelling approach is becoming insufficient for providing the information required. The purpose of this work is to demonstrate the successful implementation of a state of the art rapid prototyping ECU system using a real time 1-D gas dynamics model in closed loop control on a real engine. The model is capable of calculating all crank resolved engine parameters such as in-cylinder pressure, intake & exhaust manifold pressures and temperatures, specific cylinder trapped AFRs, mass flow and EGR prediction, etc.

This contribution shows the latest achievements in using a real-time 1-D gas dynamics model in an engine control strategy. This approach is first demonstrated on a real-time engine model running in an ECU used for closed-loop control to reduce emissions, and secondly, on an application illustrating the real-time 1-D gas dynamics model’s capabilities in sensorless control where selected major sensors are replaced by virtual sensors without any negative effects on engine performance, responses and emissions.

Ricardo has used its advanced rapid prototyping ECU, rCube2, equipped with an additional CPU where WAVE-RT (Ricardo’s real-time 1-D gas dynamics model) is running faster than real time and providing all requested parameters with a slight time advance. The rCube2 embedded processing unit is a modular prototyping system intended for control strategy development in an automotive environment. Applications are developed in MATLAB®/Simulink® and integrated into the AUTOSAR (AUTomotive Open System ARchitecture) compliant base software. WAVE-RT is Ricardo’s real-time, crankangle resolved and physically-based engine modelling simulation software designed for SiL, HiL testing of engine management systems and future ECUs. The WAVE-RT model is created from a pre-existing, validated WAVE (standard 1-D gas dynamics software) model which covers, in detail, modelling of individual cylinders, real engine geometry, boosting system, etc.