Cylinder Pressure Based Closed-Loop Control

  Copyright: RWTH Aachen | VKA

In addition to powertrain hybridization and electrification, further optimization of the engine combustion process is required. Particularly promising is the cylinder pressure based closed loop control. This requires a very fast response to the combustion processes. For this purpose, measurement of the cylinder pressure and calculation of parameters in real time are essential. Important parameters are the indicated mean effective pressure and the combustion phasing α50. A promising approach is to perform input signal preprocessing and filtering by using field-programmable gate array (FPGA).

Due to the high performance of FPGAs it is possible to achieve significant acceleration of the control functions with minimal system latency. Future combustion processes require increasing calculation complexity. The expandability of FPGAs offers the new degrees of freedom to meet future demands.

In-Cycle combustion control is of particular interest for auto ignition of gasoline fuels GCAI (Gasoline Controlled-Auto-Ignition). GCAI allows high efficiency and very low NOx-emissions by using high conversion rates. Challenging are high fluctuations of the indicated mean effective pressure and combustion phasing. These lead to unsteady engine operation and low efficiencies. In-cycle control compensates the fluctuations, increases the efficiencies and expands the GCAI operation range.

Current research activities evaluate different in-cycle control concepts on the engine test bench. A one-cylinder research engine is equipped with MicroAutobox from dSPACE and an FPGA expansion module for engine investigations. The use of an electromagnetic valvetrain (EMVT) allows ultra-fast interventions in gas exchange of the current cycle. Fundamental engine process effects can be investigated and transferred to mass-production engines in a next step.

 

Projects

FOR 2401

A state-of-the-art approach for closed-loop control of low temperature combustion processes are cycle-based control algorithms. However, these approaches allow only a stable operation in a very limited engine-map. Cycle-based controllers act such that only the system dynamics and disturbances which occur at a cycle-averaged time scale can be controlled.
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Contact

Name

Feihong Xia

Research Associate

Phone

work
+49 241 80 48269

Email

E-Mail

Contact

Name

Julian Bedei

Research Associate

Phone

work
+49 241 80 48244

Email

E-Mail
 

Selected Publications

Reduced Order Modeling for Multi-Scale Control of Low Temperature Combustion Engines

Development and experimental validation of a real-time capable field programmable gate array-based gas exchange model for negative valve overlap

Potential of Real-Time Cylinder Pressure Analysis by using Field Programmable Gate Arrays

Autoregressive modeling of cycle-to-cycle correlations in homogeneous charge compression ignition combustion

Model-based control of gasoline-controlled auto-ignition

Decoupling of consecutive gasoline controlled auto-ignition combustion cycles by field programmable gate array based real-time cylinder pressure analysis

A Study on In-Cycle Combustion Control for Gasoline Controlled Autoignition

NVH Optimization of Range Extender Engines by Electric Torque Profile Shaping