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Published February 14, 2017 | public
Journal Article

A Comparison of Three Ion Sensing Circuits in a Homogeneous Charge Compression Ignition Engine

Abstract

The use of a spark plug ion sensor to detect combustion timing in a homogeneous charge compression ignition (HCCI) engine is a technique that could alleviate the need for pressure transducers, a more expensive alternative. One disadvantage of this approach is the difficulty in obtaining a strong signal at lower equivalence ratios. This article addresses and compares three ion sensing circuitries, namely a voltage follower, a notch filter circuit that removes the 60-Hz wall noise, and a notch filter whose output is coupled to a custom-built "integrator" circuit. The circuit optimizations are aimed at improving signal strength and reliability. The ion signal present in the combustion chamber is experimentally investigated in a 1.9-L Volkswagen engine, modified for HCCI operation and fueled with gasoline. Experiments are conducted across different intake temperatures, pressures, and equivalence ratios. It was found that the custom-built circuit provided the best ion signal strength and reliability.

Additional Information

© 2017 Taylor & Francis. Received 12 Jul 2016, Accepted 09 Feb 2017, Accepted author version posted online: 14 Feb 2017, Published online: 14 Feb 2017.

Additional details

Created:
August 19, 2023
Modified:
October 25, 2023