Sensor System and Observer Algorithm Co-Design For Modern Internal Combustion Engine Air Management Based on H2 Optimization

Xu Zhang,Gregory M. Shaver,Carlos A. Lana,Dat Le,David Langenderfer,Dheeraj Gosala

doi:10.3389/fmech.2021.611992

Xu Zhang, Gregory M. Shaver + Show 4 more

Open Access

https://doi.org/10.3389/fmech.2021.611992

Copy DOI

Abstract

This paper outlines a novel sensor selection and observer design algorithm for linear time-invariant systems with both process and measurement noise based on H2 optimization to optimize the tradeoff between the observer error and the number of required sensors. The optimization problem is relaxed to a sequence of convex optimization problems that minimize the cost function consisting of the H2 norm of the observer error and the weighted l1 norm of the observer gain. An LMI formulation allows for efficient solution via semi-definite programing. The approach is applied here, for the first time, to a turbo-charged spark-ignited engine using exhaust gas circulation to determine the optimal sensor sets for real-time intake manifold burnt gas mass fraction estimation. Simulation with the candidate estimator embedded in a high fidelity engine GT-Power model demonstrates that the optimal sensor sets selected using this algorithm have the best H2 estimation performance. Sensor redundancy is also analyzed based on the algorithm results. This algorithm is applicable for any type of modern internal combustion engines to reduce system design time and experimental efforts typically required for selecting optimal sensor sets.

Highlights

The control of fuel and air in spark-ignited engines has increasingly become a challenge with the incorporation of turbo-charging, exhaust gas recirculation (EGR), valvetrain flexibility, and more stringent emission regulations
Previous studies in the field of engine air handling system management have focused on the observer design based on pre-selected sensor sets
Since this paper focusing on selecting the optimal sensor set among candidate sensors for the engine system rather than studying the differences between the engine model and actual system, a quick and simple approximation method of the process noise described in Section 3.2 was used

Summary

Introduction

The control of fuel and air in spark-ignited engines has increasingly become a challenge with the incorporation of turbo-charging, exhaust gas recirculation (EGR), valvetrain flexibility, and more stringent emission regulations. To enable effective stoichiometric air-to-fuel ratio control, the engine flow and composition must be accurately and robustly measured or estimated. Previous studies in the field of engine air handling system management have focused on the observer design based on pre-selected sensor sets Considering the increasing complexity of today’s engine systems and sensor characteristics, the choice of optimal air handling sensor set is not obvious; and it can be time-consuming and error prone if ‘guess and check’ experimental or simulation approaches are used. In order to effectively solve the problem, an algorithm for optimal sensor selection and observer design for the engine air handling system is outlined and demonstrated in this paper

Results

Discussion

Conclusion