Patent ID: 9212611
Filing Date: 2015-12-15
Classification: F01L,F02D

Abstract:
1. A method for determining movement of a component that moves towards a position defined by a limit stop in an internal-combustion engine ( 1 ), the said method comprising the steps of: controlling the arrangement of at least one acoustic microphone ( detecting, by the acoustic microphone ( memorizing in a memory buffer, the intensity (S) of the signal generated by the impact of the component against the limit stop according to the engine angle detected by the acoustic microphone ( determining two detection windows (W, V) expressed in engine angle and having each a respective start engine angle (αw_start, αv_start) and a respective finish engine angle (αw_finish, αv_finish); comparing the intensity (S) of the signal within the two detection windows (W, V); determining the extension of an analysis window (Y) of the intensity (S) of the signal based on the comparison between the intensity (S) of the signal within the two detection windows (W, V), wherein start engine angle (αw_start) of the first detection window (W) corresponds to about a −15° engine angle with respect to an upper combustion top dead centre (TDC) of a respective cylinder ( detecting, by the microphone ( determining the at least one of the impact instant and impact intensity by analyzing the intensity (S) of the signal within the analysis window (Y); determining a mean value of the at least one of the impact instant and impact intensity of the component against the limit stop; and determining an error (E) from the comparison between the mean value of the at least one of the impact instant and impact intensity of the component against the limit stop and at least one of the impact instant and impact intensity of the component against the limit stop; controlling the movement of the component that moves toward a position defined by a limit stop by using the impact of the component against the limit stop as feedback in a closed loop control; filtering the intensity (S) of the signal within the analysis window (Y) by a band-pass filter; detecting and memorizing the energy (E) of the filtered signal within the analysis window (Y) in a time interval around the instant of the impact; establishing a number (N) of cycles and a correlation law of the energy (E) of the filtered signal (S) with the impact speed of the component detecting and memorizing in the memory buffer a number (N) of values of the impact speed of the component obtained from the correlation with the energy (E) of the filtered signal (S) within the analysis window (Y), equal to the number (N) of cycles; and determining the impact speed of the component by using the mean of the values of impact speed obtained from the filtered signal within the analysis window (Y).