Knock is a fundamental phenomenon in combustion engines, and knock control is central in any engine management system. Better understanding of knock, and weak knock in particular, is considered from two main aspects: knock detection and knock characterization. The aim of knock detectors is both to detect knock and to estimate the crank angle at knock onset. Focusing on weaker knock than before, it is shown that knock detectors and algorithms have to take into account other characteristics of knock traces than the standard model. It is shown that the best-performing knock detector of those investigated is one that supervises changes in signal variance, except for low signal-to-noise ratios where it is advantageous to use also the oscillation frequency. Regarding characterization, an important result is that in a wide range of intensities there is an almost linear dependence between the logarithmic normalized knock energy and the rate of cycles with knock. This means for example that a knock controller can use feedback on the rate of cycles with knock instead of knock intensity and vice versa; both can in combination with better detection provide possibilities for smoother and more anticipatory control schemes.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Weak knock characterization and detection for knock control


    Contributors:
    Nilsson, Y (author) / Frisk, E (author) / Nielsen, L (author)


    Publication date :

    2009-01-01


    Size :

    23 pages




    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    English




    Weak knock characterization and detection for knock control

    Nilsson,Y. / Frisk,E. / Nielsen,L. et al. | Automotive engineering | 2009


    Weak knock characterization and detection for knock control

    Nilsson, Y. / Frisk, E. / Nielsen, L. | Tema Archive | 2009



    Knock Frequency-Based Knock Control

    Kulzer, André / Bargende, Michael / Grill, Michael et al. | SAE Technical Papers | 2022


    Different Methods of Knock Detection and Knock Control

    Schmillen, Karl P. / Rechs, Manfred | SAE Technical Papers | 1991