A Comparison of Three Ion Sensing Circuits in a Homogeneous Charge Compression Ignition Engine. Issue 8 (3rd August 2017)

• Record Type: Journal Article
• Authors: Phan, Tung M.; Mack, J. Hunter; Butt, Ryan H.; Dibble, Robert W.
• Is Part Of: Combustion science and technology. Volume 189:Issue 8(2017)
• Page Start: 1294
• Page End: 1306
• Publication Date: 2017-08-03
• Subjects: Circuits -- Engine -- Homogeneous charge compression ignition (HCCI) -- Ion signal -- Sensor; Combustion -- Periodicals; Combustion engineering -- Periodicals; 541.36105
• DOI: 10.1080/00102202.2017.1294587
• Languages: English
• ISSNs: 0010-2202

Abstract

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.