Method for diagnosing the dynamics of a sensor in the fresh air or exhaust gas tract of internal combustion engines

Abstract

A method for diagnosing the dynamics of a sensor in the fresh air or exhaust gas tract of internal combustion engines, as well as a computer program, a computer program product and a corresponding vehicle. It is provided that a corresponding sensor for measuring a pressure signal in the fresh air or exhaust gas tract of an internal combustion engine of a vehicle, which is coupled with a control and computing unit, is checked with respect to its dynamic characteristics. Measured values of differing frequency ranges are measured, these being used as the basis for a calculation of a characteristic. After the calculation, the characteristic is compared with a threshold value stored in a user-defined manner in the control and computing unit. If the calculated characteristic deviates from the threshold value, at least one triggering signal is triggered, so that an impaired sensor dynamic of the sensor is displayed.

Claims

1. A method for diagnosing dynamics of a sensor in a fresh air or exhaust gas tract of an internal combustion engine, the method comprising: coupling a sensor for measuring a pressure signal in the fresh air or exhaust gas tract of the internal combustion engine of a vehicle with a control and computing unit; transmitting measured values, collected with the aid of the sensor at differing frequency ranges, to the control and computing unit; calculating a characteristic using the measured values collected at the differing frequency ranges; comparing the calculated characteristic with a threshold value stored in a user-defined manner in the control and computing unit; and triggering a least one triggering signal if the calculated characteristic deviates from the threshold value so that an impaired sensor dynamic of the sensor is displayed.

2. The method according to claim 1, wherein the at least one triggering signal is triggered if the calculated characteristic is smaller than the threshold value.

3. The method according to claim 1, wherein the measured values are collected over a time interval of 2 ms to 300 ms, 15 ms to 280 ms, 30 ms to 240 ms, during at least one engine revolution or during a maximum of ten engine revolutions.

4. The method according to claim 1, wherein the sensor is designed to collect the measured values in the range of 10 Hertz to 6,000 Hertz.

5. The method according to claim 1, wherein the measured values collected at the differing frequency ranges each differ at least by a factor of five.

6. The method according to claim 1, wherein, during the calculation of the characteristic, high-frequency measured values, in the measurement interval between 800 Hertz and 6,000 Hertz, are added up and subsequently normalized with at least one low-frequency measured value that is in the measurement interval between 50 Hertz and 300 Hertz.

7. The method according to claim 1, wherein the measured values are transformed into a frequency domain with the aid of an FFT method prior to calculating the characteristic.

8. The method according to claim 1, wherein the FFT method is a Goertzel method.

9. The method according to claim 1, wherein the sensor is designed to be used in a camshaft adaptation method.

10. The method according to claim 1, wherein the control and computing unit is designed to at least partially carry out tasks of an engine controller, or the control and computing unit is coupled with an engine controller of the vehicle.

11. The method according to claim 1, wherein the triggering signal is used for further calculation and control processes in the vehicle.

12. The method according to claim 1, wherein the triggering signal is displayed in at least one output apparatus of the vehicle or on at least one screen apparatus of the vehicle.

13. A non-transitory computer-readable medium storing a computer program product having program code thereon that, when executed on a computer, causes the computer to carry out the method according to claim 1.

14. A vehicle comprising the computer-readable medium storing the computer program product according to claim 13.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

(2) FIG. 1 shows a method flowchart of a method for diagnosing the dynamics of a sensor in the fresh air or exhaust gas tract of internal combustion engines; and

(3) FIG. 2 shows a schematic representation of a vehicle comprising a computer program and a computer program product.

DETAILED DESCRIPTION

(4) FIG. 1 shows a method flowchart 100 of a method for diagnosing the dynamics of a sensor in the fresh air or exhaust gas tract of internal combustion engines. In a first method step 110, a sensor for measuring a pressure signal in the fresh air or exhaust gas tract of an internal combustion engine of a vehicle is coupled with a control and computing unit. In a second method step 120, at least one measured value of different frequency ranges, collected with the aid of the sensor, is transmitted in each case to the control and computing unit. In a third method step 130, a characteristic is calculated, using the measured values of different frequency ranges. In a fourth method step 140, the calculated characteristic is compared with a threshold value stored in a user-defined manner in the control and computing unit. In a fifth method step 150, at least one triggering signal is triggered if the calculated characteristic deviates from the threshold value, so that an impaired sensor dynamic of the sensor is displayed.

(5) Instead of discrete orders, the frequency range may also be used, as is common for an application of an FFT method. A normalizing step may also be completed during the calculation. Alternatively, any method may be used, with the aid of which the spectral power density is obtained. Other spectral components of the characteristic sensor power density may also be used. The threshold for detecting a sensor which is not okay may have other dependencies. In a combustion engine or an internal combustion engine, the relevant frequency range changes, depending on the engine rotational speed. Accordingly, the orders are used as multiples of the fundamental frequency (engine rotational speed). The amplitude has proven to be the most suitable spectral component for the necessary requirements.

(6) The described method may also be referred to as a diagnosis of the sensor dynamic by calculating the noise output.

(7) FIG. 2 shows a schematic representation of a vehicle 10 comprising a computer program 12 and a computer program product 14. It is conceivable that the illustrated vehicle comprises either the computer program or the computer program product.

(8) The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.