Method for failure detection of injectors in an internal combustion engine, control unit and system for carrying out a method
First Claim
1. A method for failure detection of injectors in an internal combustion engine, including the steps of:
- measuring a crank angle signal;
transforming said crank angle signal into a frequency range using discrete Fourier-transformation;
sequentially turning off each of a number of injectors one time;
sequentially capturing and storing one time an angle of the harmonic of the 0.5th order of said Fourier-transformed crank angle signal for each said turned off injector;
continuously capturing and storing an angle and an amount of the harmonic of the 0.5th order of said Fourier-transformed crank angle signal;
continuously comparing said continuously captured amount with a predetermined threshold value and detecting an injector failure if said continuously captured amount exceeds said predetermined threshold value; and
comparing said continuously captured angle with said sequentially captured angles stored for each said turned off injector, if said injector failure has been detected, and identifying said failed injector as an injector for which a stored sequentially captured angle corresponds.
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Accused Products
Abstract
The invention relates to a method for detecting the failure of injectors in an internal combustion engine, comprising the following steps: measuring a crank angle signal; transforming the crank angle signal into the frequency range by means of a discrete Fourier transformation; switching off each injector once and in a sequential manner; detecting and storing an angle of the harmonic of the 0.5th order of the Fourier-transformed crank angle signal for each switched-off injector once and in a sequential manner; continuous detection and storage of an angle and an amount of the harmonic of the 0.5th order of the Fourier-transformed crank angle signal; continuous comparison of the continuously detected amount with a predetermined threshold value, and determining a failure of the injector when the amount exceeds the predetermined threshold value; comparing the continuously detected angle with the angles stored for each switched-off injector when a failure of the injector is detected, and identifying the failed injector with an injector, for which a matching, stored angle is found.
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Citations
10 Claims
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1. A method for failure detection of injectors in an internal combustion engine, including the steps of:
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measuring a crank angle signal; transforming said crank angle signal into a frequency range using discrete Fourier-transformation; sequentially turning off each of a number of injectors one time; sequentially capturing and storing one time an angle of the harmonic of the 0.5th order of said Fourier-transformed crank angle signal for each said turned off injector; continuously capturing and storing an angle and an amount of the harmonic of the 0.5th order of said Fourier-transformed crank angle signal; continuously comparing said continuously captured amount with a predetermined threshold value and detecting an injector failure if said continuously captured amount exceeds said predetermined threshold value; and comparing said continuously captured angle with said sequentially captured angles stored for each said turned off injector, if said injector failure has been detected, and identifying said failed injector as an injector for which a stored sequentially captured angle corresponds. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An engine control unit for an internal combustion engine, said engine control unit implementing a series of steps, said series of steps comprising:
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measuring a crank angle signal; transforming said crank angle signal into a frequency range by way of discrete Fourier-transformation; sequentially turning off each of a number of injectors one time; sequentially capturing and storing one time an angle of the harmonic of the 0.5th order of said Fourier-transformed crank angle signal for each said turned off injector; continuously capturing and storing an angle and an amount of the harmonic of the 0.5th order of said Fourier-transformed crank angle signal; continuously comparing said continuously captured amount with a predetermined threshold value and detecting an injector failure if said continuously captured amount exceeds said predetermined threshold value; and comparing said continuously captured angle with said sequentially captured angles stored for each said turned off injector, if said injector failure has been detected, and identifying said failed injector as an injector for which a stored sequentially captured angle corresponds.
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10. A system to detect injector failure in an internal combustion engine, comprising
a detection device designed to capture a crank angle signal; -
a converter designed to transform said crank angle signal into a frequency range by way of discrete Fourier transformation; a switching device designed to sequentially turn off a number of injectors of the internal combustion engine; a first memory device designed to capture and store an angle of the harmonic of the 0.5th order of said crank angle signal for each said turned off injector; a second memory device designed to continuously capture and store an angle and an amount of the harmonic of the 0.5th order of said crank angle signal; a first comparison device designed to continuously compare said amount stored in said second memory device with a predetermined threshold value, said first comparison device being further designed so that it detects an injector failure when said amount exceeds said predetermined threshold value; a second comparison device designed to compare said angle stored in said second memory device with each said angle stored in said first memory device when said injector failure occurs, said second comparison device being further designed so that it identifies said failed injector as an injector for which an angle stored in said first memory device corresponds.
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Specification