DE102019216158A1 - Method and system for evaluating the operation of an internal combustion engine - Google Patents

Abstract

The invention relates to a method for evaluating the operation of an internal combustion engine (2) of a vehicle (1) by means of at least one first ultrasonic transducer (21), in which signals from an exhaust system (11) of the internal combustion engine (2) received by the at least one first ultrasonic transducer (21) ) are fed to an evaluation device (20) as input values.

Description

Technical area

The invention relates to a method for evaluating the operation of an internal combustion engine by means of at least one ultrasonic transducer, which is used to infer a road condition that may be critical for a vehicle and / or the condition of an exhaust system of the vehicle. The invention also relates to a system for carrying out the method according to the invention as well as a computer product program and a storage medium for a computer product program.

State of the art

A method for evaluating the operation of an internal combustion engine with the features of the preamble of claim 1 is from DE 10 2014 108 865 A1 known. The known method is used in a hybrid vehicle to detect the operation of an internal combustion engine of the hybrid vehicle. For this purpose, at least one first ultrasonic transducer is arranged in such a way that its transmitted signals encounter the exhaust gases emerging from the vehicle's exhaust system when the internal combustion engine is in operation. Based on the sound waves reflected by the exhaust gases, it is possible to recognize the operation of the internal combustion engine. This is used to ensure that, for example, when reversing the hybrid vehicle, its electric motor is used and its internal combustion engine is switched off at the same time.

Furthermore, it is known from the prior art to detect the degree of wetness of a roadway by means of at least one ultrasonic transducer, for which purpose the noise level, i.e. the basic level of the signals received by the ultrasonic transducer in passive operation, is evaluated. This basic level or noise is increased when driving over a wet road, e.g. by splashing water, etc. compared to driving on a dry road. The detection of the degree of wetness of a roadway can be used, for example, to inform the driver of an impending risk of aquaplaning or to serve as an input variable for at least partially autonomous operation of the vehicle.

Disclosure of the invention

The method according to the invention for evaluating the operation of an internal combustion engine with the features of claim 1 has the advantage that, on the one hand, it enables a roadway condition that may be critical when driving, in particular an increased degree of wetness of the roadway, to be identified particularly reliably and / or on the other hand, it opens up the possibility to infer the condition of a vehicle's exhaust system, for example to identify whether the exhaust system is defective.

The invention is based on the idea that the noises emitted by an exhaust system during operation of the internal combustion engine, which are expressed in the at least one ultrasonic transducer as noise or in increased basic values of received signals (compared to a state in which the internal combustion engine is not operated) to be compared with the expected aging or operational noise values of the exhaust system.

The noise values to be expected in the exhaust system are in particular dependent on the age or the operating hours, with a temperature load on the components of the exhaust system also having to be taken into account. With regard to the operational noise values of the exhaust system, these depend in particular on the speed of the internal combustion engine and possibly other operating parameters. In particular, it is also known that the noises or the noise levels increase over the service life of the exhaust system due to wear and tear or damage to insulating materials or similar elements installed within the exhaust system. This aging or operation-related increase in noise or noise values should be taken into account insofar as it should not be deduced from this, for example, that the roadway is more wet if increased noise values occur that are related to the circumstances mentioned above.

Against the background of the above explanations, the teaching of the invention suggests that life-time or operation-dependent signals of the exhaust system are stored or calculable in an evaluation device, and that for at least indirect detection of a current road condition and / and for determining the condition of the exhaust system the evaluation device carries out a comparison between the input signals of the at least one ultrasonic transducer and the service life or operation-related signals by means of an algorithm.

Advantageous developments of the method according to the invention for recognizing the operation of an internal combustion engine are listed in the subclaims.

In contrast to the method known at the outset from the prior art, the method according to the invention is characterized in that the received signals of the at least one ultrasonic transducer are noise values of noises from the exhaust system during operation of the internal combustion engine. Such a method makes it possible thus that the ultrasonic transducer can only be operated in a passive mode and, in contrast to the prior art, therefore does not have to be in an active or ultrasound-emitting state.

As also explained, it can be provided in particular that the algorithm in the evaluation device is used to determine a degree of wetness in the roadway, and that the signals recorded by the at least one ultrasonic transducer are only taken into account to determine the degree of wetness if the measured signals are over lifetime or operation-dependent signals from the exhaust system.

Conversely, this means that in the event that the detected signals of the at least one ultrasonic transducer is in the range or even below the expected signals, it cannot be concluded that there is increased ambient noise, which is typical, for example, for an increased degree of wetness in the roadway.

A particularly reliable interpretation of the values recorded by the at least one first ultrasonic transducer is made possible if ambient signals are additionally detected by means of at least one second ultrasonic transducer and that the at least one second ultrasonic transducer receives at least essentially no signals from the exhaust system. In other words, this means that the at least one second ultrasonic transducer is used to (exclusively) detect ambient or road noises. If these are known, they can be taken into account in the acquisition or evaluation of the signals acquired by the at least one other or first ultrasonic transducer or the signals acquired by the at least one first ultrasonic transducer can be corrected by the signals acquired by the at least one second ultrasonic transducer.

The method according to the invention also makes it possible, by comparing the detected noise values with the noise values to be expected of the exhaust system, to infer an aging or operational condition of the exhaust system which, with increasing aging or wear, is typically associated with increased noise from the exhaust system. In order to avoid increased noise pollution of the environment in this regard, a further embodiment of the method according to the invention provides that the operation of the internal combustion engine is controlled by the detected signals of the exhaust system in such a way that the speed of the internal combustion engine is limited in the event of a signal that is higher than an expected signal and / or a notice is generated. The speed limitation of the internal combustion engine typically leads to a reduction in the maximum noise of the internal combustion engine. In the context of the invention, a reference is understood to mean that, for example, the driver is given a visual reference to the defective exhaust system or the exhaust system having an increased noise level. Alternatively or in addition, such a notice can of course also be stored in a diagnostic system of the vehicle in order to provide a workshop with a corresponding notice the next time it visits the workshop.

Alternatively or additionally, it can also be provided to control the operation of the internal combustion engine in such a way that the detected signals of the exhaust system are in the range of the signals to be expected. What is meant here is that, for example, its speed is limited during the entire operating time of the vehicle in such a way that desired and / or legally required noise levels are maintained, with the speed limitation allowing a relatively small distance from the (noise) limit values.

Furthermore, the invention also includes a system for performing the method according to the invention described so far, the system having at least one ultrasonic transducer for detecting signals from the exhaust system and an evaluation device with an algorithm for comparing the signals received from the at least one first ultrasonic transducer with a stored or calculable service life - or operation-dependent signals of the exhaust system.

The invention also includes a computer product program that is designed to execute and / or implement a method according to the invention, as well as a storage medium, in particular as part of a control device of the vehicle, on which the computer product program is stored.

Further advantages, features and details of the invention emerge from the following description of preferred embodiments of the invention and with reference to the drawings.

Figure list

• 1 shows a simplified representation of a vehicle traveling along a roadway and
• 2 a flow chart to explain the method according to the invention.

Embodiments of the invention

The same elements or elements with the same function are provided with the same reference numbers in the figures.

In the 1 is a vehicle 1 shown, which travels along a roadway FB at a speed v. The vehicle 1 has an internal combustion engine 2 on, its exhaust system 11 also an example of a muffler 22nd with two tailpipes 12th , 13th includes. Inside the exhaust system 11 can at least one sensor 15th be arranged, which is designed to monitor the operating state of the exhaust system 11 capture. In particular, the at least one sensor 15th be designed as a temperature sensor. The signals from the at least one sensor 15th become a control device 20th as part of a system 10 for evaluating the operation of the internal combustion engine 2 supplied as input values.

The vehicle also includes 1 at least one first ultrasonic transducer 21 , the arrangement or design is such that the operation of the internal combustion engine 2 in the area of the exhaust system 11 , for example in the area of the tailpipes 12th , 13th emitted sound waves SW are detected. For this purpose, there is at least one first ultrasonic transducer 21 for example near the tailpipes 12th , 13th or the muffler 22nd the exhaust system 11 arranged.

In addition, the vehicle includes 1 at least one second ultrasonic transducer 23 , wherein the at least one second ultrasonic transducer 23 is designed to detect environmental noises, in particular noises from the roadway FB. Two second ultrasonic transducers are exemplary 23 in the area of the rear right wheel arch of the vehicle 1 intended. Alternatively or additionally, a second ultrasonic transducer installed in the area of the front or rear bumper for distance measurement during parking maneuvers can also be used 23 be provided. Both the signals of the at least one first ultrasonic transducer 21 , as well as the signals of the at least one second ultrasonic transducer 23 become the control device 20th supplied as input values.

The control device 20th assigns an algorithm 25th which is designed to, at least that of the first ultrasonic transducer 21 to process incoming signals. Furthermore are in the control device 20th or in the algorithm 25th Lifetime or operation-dependent signals or values for the sound waves SW of the exhaust system 11 saved. Instead of stored values, a function for calculating the values can alternatively be provided so that stored values do not have to be used. The stored or calculable values are characteristic of the signals of sound waves SW that are generated by means of a first ultrasonic transducer 21 detected when there is a typical aging process in the exhaust system 11 adjusts or the internal combustion engine 2 is operated, for example, at a corresponding speed n. Whether such a typical aging process is present can be determined, for example, by means of the at least one sensor 15th be evaluated, since its signals provide information about the aging of the exhaust system 11 can give, as this in particular also depends on the temperature profile of the exhaust system 11 is dependent. If necessary, for example when determining a due to the operating conditions or the speed n of the internal combustion engine 2 Increased noise level or amplified sound waves SW, the stored or calculated basic values can be adapted or corrected accordingly.

The algorithm 25th leads when driving the vehicle 1 on the roadway FB a comparison between the at least one first ultrasonic transducer 21 detected values of the sound waves SW with those in the control device 20th saved or calculated values. If this comparison shows that the recorded values of the sound waves SW lie in the range of the sound waves SW to be expected, it is concluded from this that there is no increased environmental noise. This suggests, for example, that a degree of wetness in the roadway FB, which indicates an increased risk of aquaplaning, is not increased either. Are those of the at least one first ultrasonic transducer 21 In contrast, the recorded values for the sound waves SW are higher than the expected service life or operation-dependent values for the sound waves SW, so it is concluded that there is increased environmental noise. However, these increased environmental noises do not necessarily have to be present, for example due to an increased degree of wetness of the roadway FB, but can also be caused, for example, by oncoming vehicles, a particularly rough road surface or the like.

Due to the time course of the signals of the at least one first ultrasonic transducer 21 However, such effects can possibly be compensated or taken into account, as is known per se from the prior art.

In addition, it is of particular advantage if the at least one second ultrasonic transducer is used at the same time 23 recorded measured values by the control device 20th or the algorithm 25th must be taken into account, since these serve (exclusively) to record environmental noises or to record a wet roadway FB.

Furthermore, the control device 20th with a motor control device 30th coupled. The engine control device 30th serves to operate the internal combustion engine 2 .

The measurement of the sound waves SW of the at least one first ultrasonic transducer results 21 that increased wear and tear or a defective exhaust system 11 is present, it can be provided that the control device 20th corresponding signals to the engine control 30th outputs, for example, the speed n of the internal combustion engine 2 to limit to a maximum speed n. Additionally or alternatively, it can be provided that the control device 20th outputs a corresponding note to the driver, or that a corresponding note in a diagnostic memory of the vehicle 1 is stored, which can be read out the next time you visit the workshop.

In the 2 the method according to the invention is explained as follows: In a first step 101 are those of the at least one first ultrasonic transducer 21 detected values for the sound waves SW of the control device 20th supplied as input values. In a second step 102 is then using the algorithm 25th a comparison of the recorded values with the expected or calculated values for the sound waves SW is carried out. This is the result of this comparison in a third step 103 that of the at least one first ultrasonic transducer 21 the recorded values are in the range of the expected values, the program leads to the first step 101 back. If, on the other hand, the comparison shows that that of the at least one first ultrasonic transducer 21 detected values for the sound waves SW is above the expected values, it is concluded that there is increased environmental noise. In a fourth step 104 these values can be analyzed and / or the values of the at least one second ultrasonic transducer 23 must be taken into account. If this comparison shows that the at least one second ultrasonic transducer 23 no increased ambient noise is recorded, so in a fifth step 105 closed to a defective exhaust system. Alternatively, in a sixth step 106 concluded that there was a risk of aquaplaning.

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 102014108865 A1 [0002]

Claims (11)

Method for evaluating the operation of an internal combustion engine (2) of a vehicle (1) by means of at least one first ultrasonic transducer (21), in which the at least one first ultrasonic transducer (21) receives signals from an exhaust system (11) of the internal combustion engine (2) of an evaluation device ( 20) are supplied as input values, characterized in that in the evaluation device (20) service life or operation-dependent signals of the exhaust system (11) are stored or calculated, and that for at least indirect detection of a current state of a roadway (FB), in particular a risk of aquaplaning for the vehicle (1) and / or, to determine the condition of the exhaust system (11), the evaluation device (20) uses an algorithm (25) to compare the input signals of the at least one first ultrasonic transducer (21) and the lifetime or carries out operation-dependent signals of the exhaust system (11). Procedure according to Claim 1 , characterized in that the received signals of the at least one first ultrasonic transducer (21) are noise values of noises from the exhaust system (11) during operation of the internal combustion engine (2). Procedure according to Claim 1 or 2 , characterized in that the at least one first ultrasonic transducer (21) is operated exclusively in a passive mode. Method according to one of the Claims 1 to 3 , characterized in that the algorithm (25) is used to determine a degree of wetness of the roadway (FB), and that the signals recorded by the at least one first ultrasonic transducer (21) are taken into account to determine the degree of wetness if the measured signals over the lifetime or operation-dependent signals of the exhaust system (11). Method according to one of the Claims 1 to 3 , characterized in that the algorithm (25) is used to determine a degree of wetness of the roadway (FB), and that the signals detected by the at least one first ultrasonic transducer (21) for determining the degree of wetness are not taken into account if the measured signals approximately match the Lifetime or operation-dependent signals of the exhaust system correspond. Method according to one of the Claims 1 to 5 , characterized in that ambient signals are additionally detected by means of at least one second ultrasonic transducer (23), and that the at least one second ultrasonic transducer (23) receives at least essentially no signals from the exhaust system (11). Method according to one of the Claims 1 to 6th , characterized in that the operation of the internal combustion engine (2) is controlled by the detected signals of the exhaust system (11) by means of an engine control device (30) in such a way that in the event of a signal that is higher than an expected signal, the maximum speed (s) of the internal combustion engine ( 2) is limited or a notice is generated. Method according to one of the Claims 1 to 7th , characterized in that the operation of the internal combustion engine (2) is controlled in such a way that the detected signals of the exhaust system (11), in particular by adapting a maximum speed (n), are in the range of the expected signals. System (10) designed to carry out a method according to one of the Claims 1 to 8th , having at least one first ultrasonic transducer (21) for detecting signals from the exhaust system (11) and an evaluation device (20) with an algorithm (25) for comparing the signals received from the at least one first ultrasonic transducer (21) with a stored or calculable service life - or operation-dependent signals from the exhaust system (11). Computer product program which is designed to implement a method according to one of the Claims 1 to 8th execute and / or implement. Storage medium, in particular as part of a control device (20), on which the computer product program is based Claim 9 is saved.

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