DE102020209197A1 - Sensor system for monitoring a fluid film - Google Patents

Abstract

The invention relates to a sensor system (100) for monitoring a fluid film (102), in particular an oil film, comprising: - a wave generator (104), - an ultrasonic sensor (106), the wave generator (104) being at a predefined distance (108) from a lubricated component (110), wherein the wave generator (104) is set up to form an ultrasonic wave in a defined frequency range due to a relative movement between the lubricated component (110) and the wave generator (104) when the fluid film (102) of lubricated component (110) falls below a predetermined limit value, the ultrasonic sensor (106) being set up to detect the ultrasonic wave in the defined frequency range, the sensor system (100) being set up to use the detected ultrasonic wave to determine a state of the fluid film (102) of the lubricated component (110).Further the invention shows a motor vehicle (200) and ei n Method for fluid film monitoring (300).

Description

The present invention relates to a sensor system for monitoring a fluid film, a motor vehicle and a method for monitoring a fluid film.

State of the art

There are currently a large number of different systems for monitoring the fluid film in lubricated components. This can be achieved, for example, by an oil level indicator, which measures an oil level in a housing in order to deduce the lubrication of the component. Furthermore, optical systems are also conceivable, which determine the degree of lubrication of the lubricated component by means of reflection. However, additional sensors are often installed in order to fulfill these functions, but this is often expensive and complex.

Disclosure of Invention

With the embodiments described below, an improved sensor system for monitoring a fluid film can be provided.

The invention is defined in the independent claims. Advantageous developments of the invention result from the dependent claims and the following description. Technical terms are used in the usual way. Where a particular meaning is conferred on a particular term, the following are definitions of terms within which the terms are used.

• -einen Wellenerzeuger,
• -einen Ultraschallsensor,

wobei der Wellenerzeuger in einem vordefinierten Abstand zu einer geschmierten Komponente angeordnet ist, wobei der Wellenerzeuger dazu eingerichtet ist, eine Ultraschallwelle in einem definierten Frequenzbereich aufgrund einer Relativbewegung zwischen einer geschmierten Komponente und dem Wellenerzeuger auszubilden, wenn der Fluidfilm der geschmierten Komponente einen vorbestimmten Grenzwert unterschreitet, wobei der Ultraschallsensor dazu eingerichtet ist, die Ultraschallwelle im definierten Frequenzbereich zu detektieren, wobei das Sensorsystem dazu eingerichtet ist, mittels der detektierten Ultraschallwelle einen Zustand des Fluidfilms der geschmierten Komponente zu ermitteln.One aspect of the invention relates to a sensor system for monitoring a fluid film, in particular an oil film, having:

• - a wave generator,
• -an ultrasonic sensor,

wherein the wave generator is arranged at a predefined distance from a lubricated component, wherein the wave generator is set up to form an ultrasonic wave in a defined frequency range due to a relative movement between a lubricated component and the wave generator when the fluid film of the lubricated component falls below a predetermined limit value, wherein the ultrasonic sensor is set up to detect the ultrasonic wave in the defined frequency range, wherein the sensor system is set up to determine a state of the fluid film of the lubricated component using the detected ultrasonic wave.

An advantage of this embodiment can be that the wave generator can be used to generate an ultrasonic wave when a fluid film of a lubricated component falls below a predetermined limit value, so that damage to the lubricated component can be avoided. In this way, existing sensors can be saved, since additional sensors can be saved with the aid of a wave generator in the form of a scraper plate, which in conjunction with ultrasonic sensors, which are typically already installed in a motor vehicle. Since the wave generator generates ultrasonic waves and these are in a frequency range that is inaudible to humans, there are no background noises. Furthermore, a state of health of the lubricant properties of the fluid film can be detected with the aid of the wave generator.

The fluid film may be an oil film or fuel film on a lubricated component such as a crankshaft or the like. The wave generator is positioned at a predefined distance from the lubricated component. The predefined distance correlates with the limit value, below which triggers the generation of the ultrasonic wave. In particular, the distance is selected in such a way that the wave generator does not form an ultrasonic wave when there is a sufficient fluid film and forms an ultrasonic wave when there is not a sufficient fluid film. Furthermore, the wave generator can be set up to form, generate and/or produce an ultrasonic wave in a defined frequency range or a defined frequency due to a relative movement and/or movement between a lubricated component and the wave generator when the fluid film of the lubricated component falls below or reaches a predetermined limit value. The ultrasonic wave can be any form and type of wave that has a frequency of at least 12 kHz. In this case, the wave generator can be made to oscillate, in particular by means of friction created by the relative movement, so that the wave generator generates, emits and/or produces an ultrasonic wave. The defined frequency range can be a frequency range of, for example, 42 to 52 kHz and/or a single frequency, such as 48 kHz. The relative movement can be any type of movement, in particular rotary or translatory movements, between the wave generator and the lubricated component. The predetermined Limit describe a state of the fluid film, such as a thickness and / or a sufficient degree of lubrication of the lubricated component. Furthermore, the ultrasonic sensor can be set up to detect and/or recognize the ultrasonic wave in the defined frequency range. The ultrasonic sensor can in particular be a parking ultrasonic sensor which is installed in a motor vehicle or the like. A sensor system can be set up to use the detected ultrasonic wave to determine, calculate and/or detect a state of the fluid film or a degree of lubrication of the lubricated component. The fluid film limit may be a variety of parameters, such as the thickness of the fluid film during relative motion between the lubricated component and the wave generator, aging of the fluid film, contamination of the fluid film, or the like. In doing so, these values can be defined using indexes in order to define the predetermined limit value, such as a lubricating film thickness of 1 mm on the lubricated component. Furthermore, the condition of the fluid film can describe an insufficient thickness of the fluid film, so that damage to the lubricated component can be avoided with the aid of the sensor system.

According to one embodiment, the wave generator is configured to be spaced apart by the fluid film from the lubricated component due to displacement of the fluid film when the fluid film is at the predetermined threshold.

An advantage of this embodiment can be that with the aid of the displacement of the fluid film, generation of the ultrasonic wave is suppressed as long as the fluid film has a necessary thickness.

For example, the fluid film is an oil film, which has a certain density and thus generates and/or forms a displacement effect in relation to the wave generator during a relative movement due to its fluid dynamics. In other words, the generation of the ultrasonic wave by displacement by the fluid film is suppressed by the wave generator as long as the fluid film does not fall below or reach the predetermined limit value and thus meets the specifications of the limit value.

In one embodiment, the predetermined fluid film limit of the lubricated component comprises at least a predetermined fluid film thickness.

An advantage of this embodiment can be that the thickness of the fluid film provides an easily definable parameter for controlling the generation of the ultrasonic wave.

In other words, the limit of the fluid film may be some sort of thickness or coverage of the fluid film on the lubricated component. The thickness of the lubricating film can be, for example, a 1 mm thick application of the fluid film on the lubricated component.

According to one embodiment, the predetermined limit value of the fluid film of the lubricated component comprises at least a ratio between at least a portion of the surface with a predetermined thickness of the fluid film of the lubricated component and at least a portion of a surface without a predetermined thickness of the fluid film of the lubricated component.

An advantage of this embodiment can be that an average value can be formed using the ratio between the surfaces that have sufficient lubrication and insufficient lubrication, in order to reduce the number of false detections.

In other words, a ratio is established between parts of the surface area of the lubricated component that have a sufficient fluid film thickness to parts of the surface area of the lubricated component that do not have a sufficient fluid film thickness. For example, the lubricated component is a shaft, with a first shaft portion having adequate lubrication and a second shaft portion not having adequate lubrication. Thus, a ratio of the lubricating film thickness can be established between the first and second shaft sections so as to define the limit value of the fluid film.

According to one embodiment, the predetermined limit of the fluid of the lubricated component comprises at least a predetermined level of contamination of the fluid film.

An advantage of this embodiment can be that damage to other components in the vicinity of the lubricated component can be avoided using the degree of contamination, since, for example, chips or similar contaminants in an oil film cannot penetrate into other components, such as an oil pump.

Contamination of the fluid film can be, for example, chips or metallic abrasion, which is typically found in an oil may occur. Above a certain degree of contamination, ie a certain proportion of solids or the like in the fluid film, the limit value of the fluid film is reached and an ultrasonic wave is formed.

According to one embodiment, the predetermined limit of the fluid of the lubricated component comprises at least a predetermined degree of aging of the fluid film.

An advantage of this embodiment can be that clogging or the like can be avoided with the aid of the degree of aging of the fluid film, since lumps or the like can increasingly form due to the aging of the fluid film.

In other words, the degree of aging of the fluid film describes a viscosity or sluggishness of the fluid film, which can be the cause of clumping or the like. A degree of aging can thus also be described with the aid of the limit value of the fluid film, so that an ultrasonic wave can be formed when the predetermined degree of aging of the fluid film is reached.

According to one embodiment, the sensor system has a large number of ultrasonic sensors, wherein the sensor system is set up to determine an original position of the ultrasonic wave of the wave generator by means of the large number of ultrasonic sensors, in particular by means of triangulation.

An advantage of this embodiment can be that a component which has insufficient lubrication can be identified by means of the detection of the original position of the ultrasonic wave.

For example, the multiplicity of ultrasonic sensors can be parking ultrasonic sensors of a motor vehicle, which are arranged in a ring-like arrangement along the outer edges of the vehicle. With the help of triangulation, an original position of the ultrasonic wave can thus be determined using the multiplicity of ultrasonic sensors due to the different arrival times at the respective ultrasonic sensors.

According to one embodiment, the wave generator is configured to emit/form a plurality of ultrasonic waves, each in a different predetermined frequency range, depending on a degree of lubrication of the fluid film.

An advantage of this embodiment can be that the multitude of ultrasonic waves can be used to determine a state of health or a remaining service life of the fluid film and/or the lubricated component, since the ultrasonic waves are formed depending on the degree of lubrication of the fluid film.

In other words, the wave generator can emit and/or form a plurality of ultrasonic waves, each in a predetermined frequency range or at a predetermined frequency, depending on the degree of lubrication of the fluid film and/or depending on the lubrication of the lubricated component. For example, the wave generator can form a first ultrasonic wave in a first predetermined frequency range when, for example, 50% of the degree of lubrication of the fluid film has been reached for the desired degree of lubrication. Furthermore, the wave generator can form a second ultrasonic wave when, for example, 80% of the degree of lubrication of the fluid film has been reached at the desired degree of lubrication. Thus, based on the detection of the first and second ultrasonic waves, the sensor system can determine whether the degree of lubrication is 50% or 80% of the lubricated component.

According to one embodiment, the sensor system has a plurality of wave generators, each of the plurality of wave generators being set up to form an individual predetermined ultrasonic wave, each individual predetermined ultrasonic wave being associated with a respective state of the fluid film, the sensor system being set up based on of the respective individual predetermined ultrasonic wave to determine a respective condition of the fluid film of the lubricated component.

An advantage of this embodiment can be that the plurality of wave generators can be used to describe different states of the fluid film of the lubricated components, with the wave generators being able to be arranged on different parts of the lubricated components in order to achieve an increase in the flexibility of the sensor system.

The sensor system can include a plurality of wave generators, each of which can be mounted at a predetermined distance from the lubricated component. The wave generators are set up in such a way that each of the wave generators forms an individual predetermined ultrasonic wave when the limit value of the fluid film is reached. Furthermore, each ultrasonic wave can be associated with a respective state of the fluid film. For example, the sensor system has a first and a second wave generator. The first wave generator generates an ultrasonic wave at a fluid film condition of 50% of the desired fluid film thickness. The second wave generator generates an ultrasonic wave at a fluid film thickness of 20% of the desired fluid film thickness. If a fluid film thickness of 50% is now reached, the first ultrasonic wave is thus generated by the first wave generator. If the fluid film is now at a condition of 20% of the desired fluid film thickness, the second wave generator generates the second ultrasonic wave. The sensor system can determine the first condition of the fluid film, for example 50% of the fluid film thickness, and the second condition, for example 20% of the fluid film thickness of the lubricated component based on the detection of the first and second ultrasonic waves.

According to one embodiment, the ultrasonic sensor has an ultrasonic microphone, in particular with a piezo element, the ultrasonic microphone being arranged at a predetermined distance and/or essentially adjacent to the lubricated component.

An advantage of this embodiment can be that by using the ultrasonic microphone at a predetermined distance and/or adjacent to the lubricated component, the reliability of the ultrasonic wave detection by the ultrasonic sensor can be increased.

The ultrasonic sensor can have, for example, an ultrasonic microphone with a piezo element, which can be attached in the vicinity and/or adjacent to the fluid-lubricated component. The ultrasonic microphone can receive the ultrasonic wave emitted by the wave generator and the sensor system can thus deduce the state of the fluid film.

According to one embodiment, the predetermined frequency range of the ultrasonic wave is between 40 kHz and 60 kHz, in particular 45 kHz and 52 kHz.

An advantage of this embodiment can be that interference with other ultrasonic systems, for example in a motor vehicle, can be avoided with the aid of the frequencies mentioned above.

The predetermined frequency range can be any frequency range that is set up or designed to form or describe an ultrasonic wave.

Another aspect is a motor vehicle, having an ultrasonic sensor, in particular a parking ultrasonic sensor, a lubricated component, a wave generator, the wave generator being arranged at a predefined distance from the lubricated component, the wave generator being set up to generate an ultrasonic wave in a defined frequency range to form a relative movement between the lubricated component and the wave generator when a fluid film of the lubricated component falls below a predetermined limit value, the ultrasonic sensor being set up to detect the ultrasonic wave in the defined frequency range, the motor vehicle being set up to use the detected ultrasonic wave to indicate a state of the fluid film of the lubricated component.

An advantage of this embodiment can be that the occupants of the motor vehicle do not perceive any disturbing noises since the wave generator generates an ultrasonic wave which is not in the audible range of the occupants. In this way, a sensor system can be implemented in the motor vehicle using simple means, which does not generate any disturbing background noise.

The motor vehicle can be a passenger car, which has ultrasonic sensors in the front area and in the rear area or circumferentially, which can be parking ultrasonic sensors in particular. Furthermore, the lubricated component of the motor vehicle can be, for example, a crankshaft of the motor vehicle or the like. In particular, the wave generator can be arranged or aligned at a predefined distance from the lubricated component. Furthermore, the wave generator can be set up to form, generate and/or emit an ultrasonic wave in a defined frequency range due to a relative movement or movement between the lubricated component and the wave generator when a fluid film of the lubricated component falls below or reaches a predetermined limit value . In this case, the ultrasonic sensor can be set up to detect, record and/or receive the ultrasonic wave in the defined frequency range. Furthermore, the motor vehicle, in particular a control unit of the motor vehicle, can be set up to use the detected ultrasonic wave to determine or calculate a state of the fluid film of the lubricated component. The ultrasonic signal can be evaluated in a control unit, preferably in the motor vehicle, for example an ultrasonic control unit, an engine control unit or a vehicle control unit. In this case, any computer and/or computer inside or outside the motor vehicle, for example a cloud system, can be used to calculate the state of the fluid film. A signal detection, esp special ultrasonic detection, transmission and / or evaluation continuously over the life of the motor vehicle in the motor vehicle itself or are determined using a cloud system. In particular, the sensor data determined by the ultrasonic sensor can be transmitted to the cloud system using a mobile radio interface.

• - Ausbilden einer Ultraschallwelle in einem definierten Frequenzbereich bei einem vorbestimmten Grenzwert eines Fluidfilms einer geschmierten Komponente durch eine Relativbewegung zwischen der geschmierten Komponente und einem Wellenerzeuger,
• - Detektieren der Ultraschallwelle im definierten Frequenzbereich, und
• - Ermitteln eines Zustands des Fluidfilms der geschmierten Komponente anhand der detektierten Ultraschallwelle.

Another aspect is a method for fluid film monitoring, comprising the steps:

• - forming an ultrasonic wave in a defined frequency range at a predetermined limit value of a fluid film of a lubricated component by a relative movement between the lubricated component and a wave generator,
• - detecting the ultrasonic wave in the defined frequency range, and
• - determining a state of the fluid film of the lubricated component based on the detected ultrasonic wave.

An advantage of this embodiment can be that the condition of the fluid film can be determined directly on the component to be lubricated with the aid of the method. Furthermore, a state of health of the component to be lubricated can be determined continuously.

For example, the ultrasonic wave can be formed due to friction between the wave generator and the lubricated component due to relative movement. The friction arises due to the absence or insufficient presence of a fluid film on the lubricated component. Furthermore, the ultrasonic wave can be detected in particular with the aid of an ultrasonic sensor. In addition, a condition of the fluid film can be determined or calculated using a computing unit, sensor unit, sensor system or the like of the lubricated component based on the detected ultrasonic wave.

Elements and/or steps of the method, as described above and below, can be features and elements of the sensor system and/or the motor vehicle and vice versa.

Further measures improving the invention are presented in more detail below together with the description of the preferred exemplary embodiments of the invention with the aid of figures.

exemplary embodiments

• 1 ein Sensorsystem gemäß einer Ausführungsform;
• 2 ein Kraftfahrzeug gemäß einer Ausführungsform;
• 3 zeigt ein Flussdiagramm zur Illustration von Schritten des Verfahrens gemäß einer Ausführungsform.

It shows:

• 1 a sensor system according to an embodiment;
• 2 a motor vehicle according to an embodiment;
• 3 12 shows a flowchart to illustrate steps of the method according to an embodiment.

• -einen Wellenerzeuger 104,
• -einen Ultraschallsensor 106,

wobei der Wellenerzeuger 104 in einem vordefinierten Abstand 108 zu einer geschmierten Komponente 110 angeordnet ist. Dabei kann der Wellenerzeuger 104 dazu eingerichtet sein, eine Ultraschallwelle in einem definierten Frequenzbereich aufgrund einer Relativbewegung zwischen der geschmierten Komponente 110 und dem Wellenerzeuger 104 auszubilden, wenn der Fluidfilm 102 der geschmierten Komponente 110 einen vorbestimmten Grenzwert unterschreitet, wobei der Ultraschallsensor 106 dazu eingerichtet ist, die Ultraschallwelle im definierten Frequenzbereich zu detektieren, wobei das Sensorsystem 100 dazu eingerichtet ist, mittels der detektierten Ultraschallwelle einen Zustand des Fluidfilms 102 der geschmierten Komponente 110 zu ermitteln. Ferner zeigt die 1 einen Ultraschallsensor 106, welcher ein Ultraschallmikrofon 112 aufweist, welches insbesondere ein Piezoelement umfasst, um die ausbildete Ultraschallwelle zu detektieren. 1 shows a sensor system 100 for monitoring a fluid film 102, in particular an oil film, having:

• - a wave generator 104,
• - an ultrasonic sensor 106,

wherein the wave generator 104 is located a predefined distance 108 from a lubricated component 110 . Wave generator 104 can be set up to form an ultrasonic wave in a defined frequency range based on a relative movement between lubricated component 110 and wave generator 104 when fluid film 102 of lubricated component 110 falls below a predetermined limit value, ultrasonic sensor 106 being set up to to detect the ultrasonic wave in the defined frequency range, the sensor system 100 being set up to determine a state of the fluid film 102 of the lubricated component 110 by means of the ultrasonic wave detected. Furthermore, the 1 an ultrasonic sensor 106, which has an ultrasonic microphone 112, which in particular comprises a piezo element in order to detect the ultrasonic wave formed.

2 FIG. 1 shows a motor vehicle 200 which has a multiplicity of ultrasonic sensors 106. FIG. The multiplicity of ultrasonic sensors 106 is arranged in particular in a ring shape and/or square shape along the outer edges of the motor vehicle 200 . The ultrasonic sensors 106 may determine an origin 114 of the ultrasonic wave using triangulation or the like. Thus, by determining the origin 114 of the ultrasonic wave, the lubricated component can be identified.

3 12 shows a flowchart to illustrate steps of the method 300. The method 300 includes the step of forming an ultrasonic wave S1. The ultrasonic wave can be formed in a defined frequency range at a predetermined threshold of a fluid film 102 of a lubricated component 110 by relative movement between the lubricated component 110 and a wave generator 104 . Furthermore, the method 300 has the step of detecting the ultrasonic wave S2. The ultrasonic wave can be in a defined frequency range be detected. In addition, the method 300 has the step of determining a state S3 of the fluid film 102 of the lubricated component 110 based on the detected ultrasonic wave.

In addition, it should be noted that "comprising" and "having" do not exclude other elements and the indefinite articles "a" or "an" do not exclude a plurality. Furthermore, it should be pointed out that features that have been described with reference to one of the above exemplary embodiments can also be used in combination with other features of other exemplary embodiments described above. Reference signs in the claims are not to be construed as limitations.

Claims (13)

Sensor system (100) for monitoring a fluid film (102), in particular an oil film, having: - a wave generator (104), - an ultrasonic sensor (106), wherein the wave generator (104) is arranged at a predefined distance (108) from a lubricated component (110), wherein the wave generator (104) is set up to form an ultrasonic wave in a defined frequency range due to a relative movement between the lubricated component (110) and the wave generator (104) when the fluid film (102) of the lubricated component (110) falls below a predetermined limit value , wherein the ultrasonic sensor (106) is set up to detect the ultrasonic wave in the defined frequency range, wherein the sensor system (100) is set up to determine a state of the fluid film (102) of the lubricated component (110) by means of the detected ultrasonic wave. sensor system claim 1 wherein the wave generator (104) is adapted to be spaced apart from the lubricated component (110) by the fluid film (102) due to displacement of the fluid film (102) when the fluid film (102) is at the predetermined threshold. A sensor system as claimed in any preceding claim, wherein the predetermined fluid film (102) limit of the lubricated component (110) comprises at least a predetermined fluid film (102) thickness. Sensor system according to one of the preceding claims, wherein the predetermined limit value of the fluid film (102) of the lubricated component (110) is at least a ratio between at least a part of a surface with a predetermined thickness of the fluid film (102) of the lubricated component (110) and at least a part a surface without a predetermined thickness of the fluid film (102) of the lubricated component (110). A sensor system as claimed in any preceding claim, wherein the predetermined limit of the fluid film (102) of the lubricated component (110) comprises at least a predetermined level of contamination of the fluid film (102). A sensor system as claimed in any preceding claim, wherein the predetermined limit of the fluid film (102) of the lubricated component (110) comprises at least a predetermined degree of aging of the fluid film (102). Sensor system according to one of the preceding claims, wherein the sensor system (100) has a plurality of ultrasonic sensors (106), wherein the sensor system (100) is set up to use the plurality of ultrasonic sensors (106) to determine an origin position (114) of the ultrasonic wave of the wave generator ( 104), in particular by means of triangulation. Sensor system according to one of the preceding claims, wherein the wave generator (104) is set up to emit/form a plurality of ultrasonic waves, each in a different predetermined frequency range depending on a degree of lubrication of the fluid film (102). Sensor system according to one of the preceding claims, wherein the sensor system (100) has a plurality of wave generators (104), each of the plurality of wave generators (104) being set up to form an individual predetermined ultrasonic wave, each individual predetermined ultrasonic wave being associated with a respective condition of the fluid film (102), wherein the sensor system (100) is set up to determine a respective state of the fluid film (102) of the lubricated component (110) on the basis of the respective individual predetermined ultrasonic wave. Sensor system according to one of the preceding claims, wherein the ultrasonic sensor (106) has an ultrasonic microphone (112), in particular with a piezo element, the ultrasonic microphone (112) being arranged at a predetermined distance from and/or substantially adjacent to the lubricated component (110). is. Sensor system according to one of the preceding claims, wherein the predetermined frequency range range of the ultrasonic wave is between 40 kHz to 60 kHz, particularly 45 kHz to 52 kHz. Motor vehicle (200) having: - an ultrasonic sensor (106), in particular a parking ultrasonic sensor, - a lubricated component (110), - a wave generator (104), the wave generator (104) being arranged at a predefined distance (108) from the lubricated component (110), wherein the wave generator (104) is set up to form an ultrasonic wave in a defined frequency range due to a relative movement between the lubricated component (110) and the wave generator (104) when a fluid film (102) of the lubricated component (110) falls below a predetermined limit value , wherein the ultrasonic sensor (106) is set up to detect the ultrasonic wave in the defined frequency range, wherein the motor vehicle (200) is set up to determine a state of the fluid film (102) of the lubricated component (110) by means of the detected ultrasonic wave. A method for fluid film monitoring (300), comprising the steps of: - forming an ultrasonic wave (S1) in a defined frequency range at a predetermined limit value of a fluid film (102) of a lubricated component (110) by a relative movement between the lubricated component (110) and a wave generator (104), -Detecting the ultrasonic wave (S2) in the defined frequency range, and - determining a state (S3) of the fluid film (102) of the lubricated component (110) based on the detected ultrasonic wave.

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