A method for detecting a crankcase ventilation line disconnection of a combustion engine, a computer program product, a non-transitory computer-readable

Abstract

A method for detecting a crankcase ventilation line disconnection of a combustion engine (12 Fig. 1) of a motor vehicle (10 Fig.1) by use of a vehicle monitoring device (14 Fig. 1) and receiving a cur

Description

[0001] The present invention relates to the field of automobiles. More specifically, the present invention relates to a method for detecting a crankcase ventilation line disconnection of a combustion engine of a motor vehicle by a monitoring device of the motor vehicle. Furthermore, the present invention relates to a corresponding computer program product, to a corresponding non-transitory computer-readable storage medium, to a corresponding monitoring device, as well as to a corresponding combustion engine. BACKGROUND INFORMATION

[0002] Some regulations mandate that monitoring for crankcase ventilation line disconnection, which led to the development of a specific diagnostic for this purpose. It is known that a vehicle speed may impact a crankcase ventilation line disconnect diagnostic, because at high vehicle speeds ram air effects as well as intake manifold pressure dynamics may prevent accurate detection of a crankcase ventilation line disconnection. Therefore, there is a need in the art to provide a more robust method for detecting a crankcase ventilation line disconnection. SUMMARY OF THE INVENTION

[0003] It is an object of the present invention to provide a method, a corresponding computer program product, a corresponding non-transitory computer-readable storage medium, a corresponding monitoring device, as well as a corresponding combustion engine, by which a crankcase ventilation line disconnection can be detected in a more reliable way.

[0004] This object is solved by a method, a corresponding computer program product, a corresponding non-transitory computer-readable storage medium, a corresponding monitoring device, as well as a corresponding combustion engine according to the independent claims. Advantageous embodiments are presented in the dependent claims.

[0005] One aspect of the present invention relates to a method for detecting a crankcase ventilation line disconnection of a combustion engine of a motor vehicle by a monitoring device of the motor vehicle. A current mass airflow to the combustion engine is captured by a mass airflow sensor device of the monitoring device. A target mass airflow to the combustion engine is determined by an electronic computing device of the monitoring device. A current velocity value of the motor vehicle is received by the electronic computing device. The current mass airflow is compared with the target mass airflow by the electronic computing device, if the velocity value is lower than a predetermined threshold. The crankcase ventilation line disconnection is detected depending on the comparison by the electronic computing device.

[0006] In particular, similar to a general air path leak check diagnostic, the vehicle speed may be used as a dependency for detecting the crankcase ventilation line disconnection. Limiting the new diagnostic to low speed operation helps to exclude high vehicle speed ram air effects as well as intake manifold positions which prevent an accurate detecting of the crankcase line disconnection.

[0007] The diagnostic work is in particular by comparing the measured mass airflow sensor reading with a modeled airflow calculation based upon intake air temperature and pressure. The unique aspect of the present invention is that it may provide the crankcase ventilation line disconnect diagnostic at a low vehicle speed to avoid unpredictable intake manifold flow dynamics.

[0008] Therefore, a more robust way for detecting the crankcase ventilation line disconnection is provided.

[0009] In particular, the method uses the vehicle speed component to limit the area in which the crankcase disconnect test is run.

[0010] The diagnostic preconditions may be a set of criteria based around ensuring that the combustion engine is in a stable condition and therefore an execution of the diagnostic may be run.

[0011] The crankcase ventilation line disconnection diagnostic may use existing sensors with no additional hardware. This serves in particular as a cost savings for the user since fewer components are needed. The diagnostic may determine if the crankcase ventilation hose has been tampered with as well. A damaged crankcase ventilation hose may allow fumes and combustion blow by (exhaust gas) to escape the motor vehicle. This diagnostic also aids the workshop or dealership in pinpointing the repair that may be required for the user.

[0012] According to an embodiment with a velocity higher than 50 km / h as the threshold the comparison is suppressed.

[0013] In another embodiment the target mass airflow is determined depending on an intake manifold temperature and pressure sensor.

[0014] In another embodiment the combustion engine is provided with a passive crankcase ventilation system.

[0015] In another embodiment, if a leak in the crankcase ventilation line and / or the crankcase ventilation line disconnection is determined, a control signal for controlling the combustion engine is generated.

[0016] In particular, the provided method is at least in part a computer-implemented method. Therefore, another aspect of the present invention relates to a computer program product comprising program code means for performing a method according to the preceding aspect.

[0017] Furthermore, the present invention relates to a non-transitory computer-readable storage medium comprising at least the computer program product according to the preceding aspect.

[0018] Another aspect of the present invention relates to a monitoring device for detecting a crankcase ventilation line disconnection of a combustion engine of a motor vehicle, comprising at least one mass airflow sensor device, and one electronic computing device, wherein the monitoring device is configured for performing a method according to the preceding aspect. In particular, the method is performed by the monitoring device.

[0019] A computing unit / electronic computing device may in particular be understood as a data processing device, which comprises processing circuitry. The computing unit can therefore in particular process data to perform computing operations. This may also include operations to perform indexed accesses to a data structure, for example a look-up table, LUT.

[0020] In particular, the computing unit may include one or more computers, one or more microcontrollers, and / or one or more integrated circuits, for example, one or more application-specific integrated circuits, ASIC, one or more field-programmable gate arrays, FPGA, and / or one or more systems on a chip, SoC. The computing unit may also include one or more processors, for example one or more microprocessors, one or more central processing units, CPU, one or more graphics processing units, GPU, and / or one or more signal processors, in particular one or more digital signal processors, DSP. The computing unit may also include a physical or a virtual cluster of computers or other of said units.

[0021] In various embodiments, the computing unit includes one or more hardware and / or software interfaces and / or one or more memory units.

[0022] A memory unit may be implemented as a volatile data memory, for example a dynamic random access memory, DRAM, or a static random access memory, SRAM, or as a non-volatile data memory, for example a read-only memory, ROM, a programmable read-only memory, PROM, an erasable programmable read-only memory, EPROM, an electrically erasable programmable read-only memory, EEPROM, a flash memory or flash EEPROM, a ferroelectric random access memory, FRAM, a magnetoresistive random access memory, MRAM, or a phase-change random access memory, PCRAM.

[0023] A still further aspect of the present invention relates to a combustion engine for a motor vehicle comprising at least the monitoring device according to the preceding aspect.

[0024] Furthermore, the present invention relates to a motor vehicle comprising at least the combustion engine according to the preceding aspect.

[0025] Advantageous embodiments of the methods are to be regarded as advantageous embodiments of the computer program product, the non-transitory computer-readable storage medium, the monitoring device, the combustion engine as well as the motor vehicle. The monitoring device, the combustion engine, as well as the motor vehicle therefore comprises means for performing the method.

[0026] Further advantages, features, and details of the present invention derive from the following description of preferred embodiments as well as from the drawings. The features and feature combinations previously mentioned in the description as well as the features and feature combinations mentioned in the following description of the figures and / or shown in the figures alone can be employed not only in the respectively indicated combination but also in any other combination or taken alone without leaving the scope of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The novel features and characteristic of the present disclosure are set forth in the appended claims. The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate exemplary embodiments and together with the description, serve to explain the disclosed principles. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system and / or methods in accordance with embodiments of the present subject matter are now described below, by way of example only, and with reference to the accompanying figures.

[0028] The drawings show in:

[0029] Fig. 1 a schematic side view according to an embodiment of a motor vehicle comprising an embodiment of a combustion engine comprising an embodiment of a monitoring device;

[0030] Fig. 2 a schematic block diagram according to an embodiment of a combustion engine comprising an embodiment of the monitoring device; and

[0031] Fig. 3 a schematic flow chart according to an embodiment of a method.

[0032] In the figures the same elements or elements having the same function are indicated by the same reference signs. DETAILED DESCRIPTION

[0033] In the present document, the word "exemplary" is used herein to mean "serving as an example, instance, or illustration". Any embodiment or implementation of the present subject matter described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

[0034] While the present disclosure is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawing and will be described in detail below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure.

[0035] The terms “comprises”, “comprising”, or any other variations thereof, are intended to cover a non-exclusive inclusion so that a setup, device or method that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or device or method. In other words, one or more elements in a system or apparatus preceded by “comprises” or “comprise” does not or do not, without more constraints, preclude the existence of other elements or additional elements in the system or method.

[0036] In the following detailed description of the embodiment of the present disclosure, reference is made to the accompanying drawing that forms part hereof, and in which is shown by way of illustration a specific embodiment in which the disclosure may be practiced. This embodiment is described in sufficient detail to enable those skilled in the art to practice the disclosure, and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the present disclosure. The following description is, therefore, not to be taken in a limiting sense.

[0037] Fig. 1 shows a schematic side view according to an embodiment of a motor vehicle 10. The motor vehicle 10 comprises a combustion engine 12. The combustion engine 12 comprises at least one monitoring device 14. The monitoring device 14 is configured for detecting a crankcase ventilation line disconnection of the combustion engine 12 of the motor vehicle 10.

[0038] Fig. 2 shows a schematic block diagram according to an embodiment of the combustion engine 12 with the monitoring device 14. In particular, Fig. 2 shows, that the monitoring device 14 comprises at least one mass airflow sensor device 16 and one electronic computing device 18. Furthermore, a temperature and a pressure sensor 20 is shown. Fig. 2 further shows that from an air filter 22 an airflow 24 is provided for the engine 12. The mass airflow sensor device 16 measures the airflow 24. Furthermore, a crankcase ventilation line 26 is shown, wherein the crankcase ventilation line 26 may also be regarded as a so-called positive crankcase ventilation (PCV).

[0039] Fig. 3 shows a schematic flow chart according to an embodiment of the method. In a first step S1 the combustion engine 12 may start. In a second step S2 a diagnosis of preconditions for the method is performed. In a third step S3 the driver of the motor vehicle may cause the motor vehicle speed to be lower than a predetermined threshold, for example below 50 km / h. In particular, therefore a vehicle velocity value 28 is received by the electronic computing device 18.

[0040] In a fourth step S4 the detecting of the crankcase ventilation line disconnection is provided. Therefore, as an input, a current mass airflow 30 as well as a target mass airflow 32 are provided for the fourth step S4. Within the fourth step S4 a leak or a disconnection is determined. A fifth step S5 is performed in the shown embodiment, wherein the combustion engine may be stopped.

[0041] Therefore, Fig. 3 shows in particular the method for detecting the crankcase ventilation line disconnection. The current mass airflow 30 of the combustion engine 12 is captured by the mass airflow sensor device 16. The target mass airflow 32 to the combustion engine 12 is determined by the electronic computing device 18. The current vehicle velocity value 28 is received by the electronic computing device 14. The current mass airflow 30 is compared with the target mass airflow 32 by the electronic computing device 14, if the vehicle velocity value 28 is lower than a predetermined threshold. The crankcase ventilation line disconnection is detected depending on the comparison by the electronic computing device 14.

[0042] In particular, when the vehicle velocity value 28 is higher than 50 km / h as the threshold the comparison is suppressed. For example, the comparison may be implemented at speeds below 50 km / h. Furthermore, the target mass airflow 32 is determined depending on an intake manifold temperature and pressure sensor 20.

[0043] Furthermore, the combustion engine 12 is provided with a passive crankcase ventilation system.

[0044] If a leak in the crankcase ventilation line and / or the crankcase ventilation line disconnection is determined, a control signal for controlling the combustion engine 12 is generated, for example the combustion engine 12 is shut down.

[0045] Therefore, the provided method uses the vehicle velocity value 28 as a dependency. Limiting the diagnostic to low speed operation improves the diagnostic by excluding high vehicle speed ram air effects as well as intake manifold positions which may prevent the electronic computing device 18 from accurately detecting the crankcase line 26 disconnection.

[0046] The diagnostic works by comparing the measured mass airflow sensor 16 reading with a model airflow calculation based upon intake air temperature and pressure. The unique aspect of the diagnosis is that it runs at low vehicle speeds to avoid unpredictable intake manifold flow dynamics.

[0047] Therefore, a crankcase ventilation hose or line pressure sensor may not be needed. The method uses the existing mass airflow sensor device 16 and for example the intake manifold temperature and pressure sensor 20 to determine if there is a leak. Furthermore, an active crankcase ventilation valve may not be used. The combustion engine 12 uses, in particular, a so-called passive crankcase system which means it does not have a valve to control the airflow 24. The diagnostic method may be implemented at low vehicle speeds. Therefore, monitoring for the crankcase ventilation line 26 leak during low vehicle speed situations to isolate a leak with the characteristics of a crankcase ventilation line or hose 26 disconnection is performed.

[0048] As the diagnostic preconditions, in particular in the second step S2, a set of criteria based around ensuring the combustion engine 12 is in a stable condition is performed. These are general requirements like engine temperatures are acceptable. The diagnostic method may be executed during a coasting maneuver by the user at, for example, 50 km / h or slower.

[0049] The crankcase ventilation line 26 disconnection diagnosis uses existing sensors. This serves as a cost savings for the user. The diagnostic may determine if the crankcase ventilation line 26 has been tampered with. A damaged crankcase ventilation line 26 may allow fumes and combustion blow by, in particular so-called exhaust gases, to escape the motor vehicle 10. This diagnostic also aids the workshop or dealership in pinpointing the repair that may be required for the user. Reference Signs motor vehicle combustion engine monitoring device mass airflow sensor device electronic computing device temperature and pressure sensor air filter airflow crankcase ventilation line vehicle velocity value current mass airflow target mass airflow S1 - S5 steps of the method

Claims

1. A method for detecting a crankcase ventilation line disconnection of a combustion engine (12) of a motor vehicle (10) by a monitoring device (14) of the motor vehicle (10), comprising the steps of:- capturing a current mass airflow (30) to the combustion engine (12) by a mass airflow sensor device (16) of the monitoring device (14);- determining a target mass airflow (32) to the combustion engine (12) by an electronic computing device (18) of the monitoring device (14);- receiving a current velocity value (28) of the motor vehicle (10) by the electronic computing device (18);- comparing the current mass airflow (30) with the target mass airflow (32) by the electronic computing device (18), if the velocity value (28) is lower than a predetermined threshold; and- detecting the crankcase ventilation line disconnection depending on the comparison by the electronic computing device (18).

2. The method according to claim 1, characterized in thatwith a velocity value (28) higher than 50 km / h as the threshold the comparison is suppressed.

3. The method according to claim 1 or 2, characterized in thatthe target mass airflow (32) is determined depending on an intake manifold temperature and pressure sensor (20).

4. The method according to any one of claims 1 to 3, characterized in thatthe combustion engine (12) is provided with a passive crankcase ventilation system.

5. The method according to any one of claims 1 to 4, characterized in that, if a leak in the crankcase ventilation line and / or the crankcase ventilation line disconnection is determined, a control signal for controlling the combustion engine (12) is generated.

6. A computer program product comprising program code means for performing a method according to any one of claims 1 to 5.

7. A non-transitory computer-readable storage medium comprising at least the computer program product according to claim 6.

8. A monitoring device (14) for detecting a crankcase ventilation line disconnection of a combustion engine (12) of a motor vehicle (10), comprising at least one mass airflow sensor device (18), and one electronic computing device (18), wherein the monitoring device (14) is configured for performing a method according to any one of claims 1 to 5.

9. A combustion engine (12) for a motor vehicle (10) comprising at least the monitoring device (14) according to claim 8.

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