DE102022201916A1 - Method for operating a sensor system - Google Patents

Abstract

Method for operating a sensor system (100), comprising the steps: a) wirelessly providing at least one data set (D) relating to an operating characteristic of a sensor device (10) of the sensor system (100); andb) using the data set (D) in the operation of the sensor system (100).

Description

The present invention relates to a method for operating a sensor system. The invention also relates to a sensor system. Furthermore, the invention relates to a computer program product. Furthermore, the invention relates to a machine-readable storage medium.

State of the art

Driver assistance functions based on ultrasonic sensors have been known for many years. Most ultrasonic sensors are similar in their structural design, with a diaphragm pot (typically made of aluminium) bonded to a piezoelectric element. In order to damp membrane vibration after excitation, the membrane pot and parts of the sensor housing are filled with a material for acoustic vibration damping, typically silicone foam, which is foamed during the manufacturing process. These parts together form the transducer, which is connected to control and evaluation electronics with wires. The transducer and the electronics connected to it form a coupled serial and parallel oscillating circuit.

A transfer function can be different for each ultrasonic sensor due to manufacturing variations. In addition, the transfer function can depend on the temperature of the sound transducer, since the vibration-mechanical properties of the sound transducer, e.g. the membrane stiffness, the hardness of the adhesive layer, the resilience of the damping foam, etc., and the electrical properties of its components, e.g. the electrical capacitance of the piezoceramic, also are temperature dependent.

EP 3 540 709 A1 discloses a road surveillance system having a plurality of sensor elements, the sensor elements being arranged along at least a portion of a road. The sensor elements each have a housing with an underside for attachment and an upper side. Furthermore, at least one sensor is provided for detecting a measured variable, with the sensor being connected to an evaluation device arranged in the housing, in particular for the autonomous evaluation of the detected measured variable. The evaluation device is designed in such a way that an event and/or a state can be determined from the recorded measured variable.

Disclosure of Invention

An object of the invention is to provide an improved method for operating a sensor system.

1. a) Drahtloses Bereitstellen wenigstens eines Datensatzes betreffend eine Betriebscharakteristik einer Sensoreinrichtung des Sensorsystems; und
2. b) Verwenden des Datensatzes im Betrieb des Sensorsystems.

According to a first aspect, the object is achieved with a method for operating a sensor system, with the steps:

1. a) Wireless provision of at least one data set relating to an operating characteristic of a sensor device of the sensor system; and
2. b) Using the data set in the operation of the sensor system.

In this way, properties of the sensor device used therein are advantageously better known to the sensor system, as a result of which a system design of the sensor system can be carried out in an improved manner. This advantageously enables the use of sensor-specific data, e.g. in the form of a family of characteristics of the sensor device. This can advantageously reduce a scattering of the transmission and reception properties of the sensor device, which can affect the transmission function for a transmission and reception case, with a transmission function being understood in this context as meaning a dependence of the echo amplitude on the transmission sound frequency of the sensor device . This includes both the frequency dependency of the sound pressure of the transmitted ultrasonic pulse and the frequency dependency of the received echo amplitude.

Acoustic-electrical properties of the sensor device, which depend on many influencing variables from production, such as quality and quality of the piezo adhesive, quality and quality of the damping foam, tolerances of the membrane pot, etc., can be taken into account in this way during operation of the sensor device.

• eine Sensoreinrichtung; und
• eine Recheneinrichtung, wobei wenigstens ein drahtlos bereitgestellter Datensatz betreffend eine Betriebscharakteristik der Sensoreinrichtung in einem Betrieb des Sensorsystems verwendet wird.
• Gemäß einem dritten Aspekt wird die Aufgabe gelöst mit einem Computerprogramm umfassend Befehle, die bei der Ausführung des Computerprogramms durch einen Computer diesen veranlassen, das vorgeschlagene Verfahren auszuführen.

According to a second aspect, the object is achieved with a sensor system having:

• a sensor device; and
• a computing device, wherein at least one wirelessly provided data set relating to an operating characteristic of the sensor device is used in an operation of the sensor system.
• According to a third aspect, the object is achieved with a computer program comprising instructions which, when the computer program is executed by a computer, cause the latter to execute the proposed method.

According to a fourth aspect, the object is achieved with a machine-readable storage medium on which the computer program is stored.

Advantageous developments of the proposed method are the subject of dependent claims.

An advantageous development of the proposed method provides that the at least one data set relating to the operating characteristics of the sensor device is determined in a manufacturing process of the sensor device.

A further advantageous development of the proposed method provides that a transmission function of the sensor device is provided wirelessly in the at least one data set. This provides a data set relating to an operating characteristic, although it goes without saying that additional or other data can also be provided wirelessly.

A further advantageous development of the proposed method provides that the at least one data set is stored in a computing device in the cloud.

A further advantageous development of the proposed method provides that the at least one data set is transmitted to a vehicle control unit of a vehicle. In this way, it is not necessary to store the data set in a sensor memory, which is usually very limited anyway.

A further advantageous development of the proposed method provides that the received data set is used for a compensation in a selection process, in particular for an amplitude correction of received echo data. In this way, a narrowing in the scattering can advantageously be achieved, which as a result enables finer compensation of sensor-specific properties.

A further advantageous development of the proposed method provides that the at least one data set is assigned to the sensor device of the sensor system via a unique ID (e.g. serial number). This supports precise use of the data corresponding to the respective sensor.

A further advantageous development of the proposed method provides that after each system start, a sensor configuration and the serial number are read out, with a check being made as to whether the data set already exists, and if the data set does not yet exist, the data set is downloaded again and is stored in the control unit. In this way, it is also checked whether the sensor with the unique specific sensor ID is installed at all. For example, the check can take place each time a parking application of the vehicle is started (usually when the vehicle is started).

A further advantageous development of the proposed method provides that current environmental data is queried using the current vehicle position, with an operating point of the sensor device being adjusted from the data set using the environmental data. This can be done, for example, from sensor data or using position data from weather maps.

Further measures that explain and improve the invention are explained in more detail below together with the description of preferred exemplary embodiments of the invention with reference to several figures.

Disclosed method features result analogously from corresponding disclosed device features and vice versa. This means in particular that features, technical advantages and versions relating to the proposed method for operating a sensor system result from corresponding versions, features and technical advantages relating to the proposed sensor system and vice versa.

character list

• 1 ein erstes Diagramm eines Kennlinienfeldes einer Sensoreinrichtung eines vorgeschlagenen Sensorsystems;
• 2 ein zweites Diagramm eines Kennlinienfeldes einer Sensoreinrichtung eines vorgeschlagenen Sensorsystems;
• 3 ein Übersichtsbild mit einer Erläuterung einer prinzipiellen Wirkungsweise des vorgeschlagenen Verfahrens; und
• 4 einen prinzipiellen Ablauf eines vorgeschlagenen Verfahrens zum Betreiben eines vorgeschlagenen Sensorsystems.

In the figures shows:

• 1 a first diagram of a family of characteristics of a sensor device of a proposed sensor system;
• 2 a second diagram of a family of characteristics of a sensor device of a proposed sensor system;
• 3 an overview image with an explanation of a basic mode of operation of the proposed method; and
• 4 a basic sequence of a proposed method for operating a proposed sensor system.

Embodiments of the invention

High demands are placed on today's ultrasonic sensors in terms of robustness, accuracy and reliability over different temperature and operating frequency ranges. Influences on the measured echo amplitude through the individual transfer function, temperature, humidity of the environment can only be compensated insufficiently and can ultimately lead to functional limitations.

In order to align the functional properties of ultrasonic sensors with one another, ultrasonic sensors are usually adjusted at a working point in the factory (e.g. with regard to sound pressure and sensitivity at a specific working frequency and ambient temperature). This ensures, at least at a specific temperature and a specific working frequency in subsequent measurement operation, that different sensors essentially deliver the same echo amplitude for the same measurement object. This is important because certain properties of the object can be inferred from the echo amplitude, such as the height of a detected object.

It is proposed, especially in new vehicle architectures with a connection to a mobile network (e.g. to the 5G wireless network), to download ultrasonic sensor-specific and ultrasonic sensor-individual properties (in particular the transmission function) from a cloud into the vehicle and to use them profitably in a sensor system with an ultrasonic sensor. In addition, local temperature and humidity data can also be transmitted via the cloud and used in the sensor system.

If a different temperature prevails during measurement than during calibration and/or if a different working frequency is selected than during calibration, the echo amplitude can deviate from the setpoint.

With the proposed method it can advantageously be achieved that the form and the temperature response of the transfer function of a sensor are known and also used during ongoing operation of an ultrasonic sensor. It follows from this that differences in the echo amplitude between different sensors can be taken into account and compensated for outside of the operating point of the adjustment.

The proposed method supports limiting the spread of the overall performance over changing environmental conditions and vehicles in sensor systems with an ultrasonic sensor with the aid of sensor-specific parameters and more precise knowledge of the outside temperature and humidity.

This data and parameters are stored in a data cloud and can be called up by the sensor system with the ultrasonic sensor if required. This has the advantage that the data does not have to be stored in the sensor itself, as a result of which material and production costs can advantageously be saved.

1. a) eine für das Sensorsystem mit dem Ultraschallsensor zugängliche drahtlose Anbindung an ein Mobilfunknetz (z.B. 5G-Netz) und Zugang zu einer Daten Cloud
2. b) die Speicherung relevanter sensorindividueller Kenngrößen wie Übertragungsfunktion, Abgleichdaten, Impedanzkurve und Ersatzparameter inklusive deren Temperaturgang und Frequenzabhängigkeit in der Daten Cloud. Diese Größen können z.B. während der Fertigung der Sensoren und deren Abgleich am Bandende an jedem Sensor gemessen werden. Denkbar ist aber auch die Bereitstellung derartiger Daten aus rechentechnischen Simulationsprozessen
3. c) Die Speicherung einer eineindeutigen Kennung bzw. ID dieser Datensätze, z.B. über die Seriennummer des Sensors. Diese eineindeutige Kennung wird in jeden Ultraschallsensor am Bandende programmiert

The following components are assumed for the proposed method:

1. a) a wireless connection to a mobile network (e.g. 5G network) accessible for the sensor system with the ultrasonic sensor and access to a data cloud
2. b) the storage of relevant sensor-specific parameters such as transfer function, adjustment data, impedance curve and substitute parameters including their temperature response and frequency dependency in the data cloud. These variables can be measured on each sensor during the manufacture of the sensors and their adjustment at the end of the line, for example. However, the provision of such data from computational simulation processes is also conceivable
3. c) The storage of a unique identification or ID of these data sets, eg via the serial number of the sensor. This unique identifier is programmed into each ultrasonic sensor at the end of the line

• Nach Systemstart (Inbetriebnahme eines Fahrzeugs mit dem vorgeschlagenen Sensorsystem):
  1. 1. In einem Fahrzeug wird nach Systemstart die Sensorkonfiguration abgefragt und die Seriennummer jedes Sensors ausgelesen.
  2. 2. Reihum wird für alle Sensoren geprüft, ob zu den Seriennummern bereits der zugehörige Datensatz für die aktuell herrschende Umgebungstemperatur im Steuergerät vorliegt.
     1. a. Falls ja: ist das Verfahren beendet
     2. b. Falls nein: Herunterladen des Datensatzes aus der Cloud und Speicherung des Datensatzes in einem Steuergerät des Fahrzeugs

A sequence of the proposed procedure can look like this:

• After system start (commissioning of a vehicle with the proposed sensor system):
  1. 1. In a vehicle, after the system starts, the sensor configuration is queried and the serial number of each sensor is read.
  2. 2. All sensors are checked in turn to see whether the corresponding data set for the current ambient temperature is already available in the control unit for the serial numbers.
     1. a. If yes: the procedure is finished
     2. b. If not: downloading the data set from the cloud and storing the data set in a vehicle control unit

• 3. Abfragen von aktuellen Umgebungsdaten (z.B. Luftfeuchte und Umgebungstemperatur) aus dem 5G-Netz anhand der aktuellen Fahrzeugposition
• 4. Abgleich mit der Fahrzeugmessung (Umgebungstemperatursensor im Fahrzeug)
• 5. Aktualisierung der Datensätze, falls die Umgebungstemperatur sich signifikant geändert hat

In an ongoing operation:

• 3. Requesting current environmental data (e.g. humidity and ambient temperature) from the 5G network based on the current vehicle position
• 4. Comparison with the vehicle measurement (ambient temperature sensor in the vehicle)
• 5. Updating the records if the ambient temperature has changed significantly

The data sets D can advantageously be transmitted to a vehicle control unit of a vehicle via the 5G network and stored there. Due to the very high bandwidth of a 5G network, this supports the data records D being very up-to-date.

An example of compensation for the temperature-dependent detection sensitivity is explained below with reference to two figures.

A transfer function of the sensor device can, for example, 1 have the course shown over the temperature T and the frequency f. The echoes received by the sensor device 10 have an amplitude proportional to the magnitude m1(T1) at a signal frequency _f1 (frequency of the ultrasonic pulse emitted by the sensor device 10). If the sensor device 10 is operated at a higher signal frequency f ₂ , the echo amplitude decreases with the same object scene in accordance with the then lower magnitude m2(T1). 1 thus shows a transfer function of the sensor device 10 at the temperature T1 as a function of the frequency f.

By downloading the magnitude values m1(T1) and m2(T1) associated with the temperature T1 currently prevailing at the sensor device 10 from the sensor database in the cloud 300, the control unit can correct the echo amplitudes for each identified sensor by multiplying them by the reciprocal of the magnitude carry out. Thus, after the correction, the echo amplitudes are independent of the working frequency and the transfer function of the sensor device 10.

2 shows another transfer function of the same sensor device 10 as that of FIG 1 , but at a different temperature T2. It can be seen that at this temperature, in contrast to 1 the magnitude m2(T2) is greater than m1(T2). During operation of the sensor device 10, the signal frequencies f ₁ , f ₂ can also be provided, for example, in the context of frequency chirps. 3 shows an overview of how the proposed method works. It can be seen that at least one data set D relating to an operating characteristic of the sensor device 10 (eg production data) is fed to a computing device 200 arranged in a cloud 300 . As an application example, the data set D can be transmitted to a sensor system 100 of a vehicle 30, which stores the data set D eg in a control unit (not shown) for further use (eg for a driver assistance system).

It can be seen that the sensor system 100 includes a sensor device 10 (for example an ultrasonic sensor). Operational data (e.g. echo data), which are recorded by the sensor device 10 during operation, are processed and evaluated by means of a computing device 20 (e.g. ASIC) functionally connected to the sensor device 10. The evaluated data can be supplied to a driver assistance system (not shown), for example in the form of a parking pilot and the like.

The shown connection of the cloud 300 with the computing device 200 to the vehicle 30 can be realized, for example, by means of a 5G network, whereby a high-performance data connection is available.

For example, the proposed sensor system 100 can be used in an electric vehicle architecture in which a few controllers assume the functions of dozens today.

Although the proposed method was explained above using an ultrasonic sensor, it goes without saying that the proposed method can also be implemented with technologically different sensor types. An application of the proposed method is advantageously not limited to sensor systems with ultrasonic sensors, but can also be applied analogously to other functions/systems.

• In einem Schritt 400 erfolgt ein drahtloses Bereitstellen wenigstens eines Datensatzes D betreffend eine Betriebscharakteristik einer Sensoreinrichtung 10 des Sensorsystems 100.

4 shows a basic sequence of a proposed procedure:

• In step 400, at least one data set D relating to an operating characteristic of a sensor device 10 of sensor system 100 is provided wirelessly.

In step 410, data set D is used during operation of sensor system 100.

It is advantageously possible to implement the proposed method at least partially or entirely in software, which supports efficient and easy adaptability of the proposed method. For example, a powerful computing device 200 in the cloud 300 can be used for implementation.

When implementing the invention, a person skilled in the art will also implement embodiments that are not explained or only partially explained.

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited 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

• EP 3540709 A1 [0004]

Claims (13)

Method for operating a sensor system (100), comprising the steps: a) Wireless provision of at least one data set (D) relating to an operating characteristic of a sensor device (10) of the sensor system (100); and b) Using the data set (D) in the operation of the sensor system (100). procedure after claim 1 , The at least one data set (D) relating to the operating characteristics of the sensor device (10) being determined in a manufacturing process of the sensor device (10). procedure after claim 1 or 2 , wherein in the at least one data set (D) a transfer function of the sensor device (10) is provided wirelessly. Method according to one of the preceding claims, wherein the at least one data set (D) is stored in a computing device (200) of the cloud (300). Method according to one of the preceding claims, wherein the at least one data set (D) is transmitted to a vehicle control unit of a vehicle. Method according to one of the preceding claims, in which the received data set (D) is used for a compensation in a selection process, in particular for an amplitude correction of received echo data. Method according to one of the preceding claims, wherein the at least one data set (D) is assigned to the sensor device (10) of the sensor system (100) via a unique ID. Method according to one of the preceding claims, that after each system start, a sensor configuration and the serial number is read out, it being checked whether the data set already exists, and if the data set does not yet exist, the data set is downloaded again and stored in the control unit becomes. Method according to one of the preceding claims, that current environmental data are queried based on the current vehicle position, with an operating point of the sensor device being adjusted from the data set based on the environmental data. Sensor system (100) comprising: - a sensor device (10); and - A computing device (20), wherein at least one wirelessly provided data set (D) relating to an operating characteristic of the sensor device (D) is used in an operation of the sensor system (100). Sensor system (100) according to claim 10 , wherein the sensor device (10) is an ultrasonic sensor. Computer program comprising instructions which, when the computer program is executed by a computer, cause the latter to carry out a method according to one of Claims 1 until 9 to execute. Machine-readable storage medium on which the computer program claim 12 is saved.

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